Aortic dissection: clinical guidelines

List of Abbreviations

AAA — abdominal aortic aneurysm

AH — arterial hypertension

TAA — thoracic aortic aneurysm

BP — blood pressure

AOS — aneurysms-osteoarthritis syndrome

TAAD — thoracic aortic aneurysm and dissection

IVUS — intravascular ultrasound

GCA — giant cell (or temporal) arteritis

SMC — smooth muscle cells

BAV — bicuspid aortic valve

CI — confidence interval

ACEI — angiotensin-converting enzyme inhibitors

IMH — intramural hematoma

TL — true lumen

CoA — coarctation of the aorta

CT — computed tomography

CTA — computed tomography angiography of the aorta

CK — creatine kinase

LCC — left coronary cusp

FL — false lumen

MRI — magnetic resonance imaging

MSCT — multislice computed tomography

NCC — non-coronary cusp

nsTAAD — non-syndromic forms of TAAD

AAS — acute aortic syndrome

RR — relative risk

PAU — penetrating atherosclerotic ulcer

RCC — right coronary cusp

PET — positron emission tomography

AD — aortic dissection

RCT — randomized controlled trial

AAS — arterial tortuosity syndrome

TS — Turner syndrome

TAI — traumatic aortic injury

TTE — transthoracic echocardiography

Level of Evidence — LE

Level of Recommendation — LR

DUS — Doppler ultrasound

US — ultrasound

FDG — fludeoxyglucose [18F]

TEE – transesophageal echocardiography

ECG — electrocardiogram

iRA – iatrogenic aortic dissection

BSA – body surface area

EDS – Ehlers-Danlos syndrome

EVAR – endovascular aneurysm repair

HR – hazard ratio

LDS – Loeys-Dietz syndrome

MIP – maximum intensity projection

MPR – multiplanar reconstruction

TEVAR – thoracic endovascular aortic repair

TGF – transforming growth factor

ULP – ulcer-like projection

Terms and Definitions

Aneurysm – a localized dilation of an artery (less commonly a vein) caused by thinning or stretching of its wall.

Intramural hematoma – a condition in which blood leaks into the middle layer of the aorta under low pressure, forming a thrombus that pushes the outer wall of the aorta outward while leaving the aortic lumen relatively normal (absence of a false lumen).

True aneurysm – an aneurysm whose walls consist of the structural elements of the vascular wall.

True aortic lumen – the aortic lumen formed during aortic dissection that has an antegrade blood flow.

False aneurysm – a blood-filled cavity located in the tissues outside an artery but communicating with it through an opening in the wall.

False aortic lumen – the aortic lumen formed during aortic dissection that has retrograde blood flow or thrombosis.

Acute aortic dissection – the period from the onset of symptoms of aortic dissection up to 14 days.

Acute aortic syndrome – a group of sudden, life-threatening conditions with similar clinical presentations associated with aortic pathology. The underlying mechanism of various AAS manifestations involves disruption of the aortic intima and media, which can lead to the formation of an intramural hematoma, penetrating aortic ulcer, aortic dissection, or rupture.

Contained aortic rupture – a condition where a patient with acute pain (typically hemodynamically stable) is found on imaging to have an aortic aneurysm with an intact wall (as opposed to disruption of all wall layers in a rupture) and a perivascular hematoma with/without pseudoaneurysm formation.

Penetrating aortic ulcer – an ulceration of an atherosclerotic plaque of the aorta that penetrates through the internal elastic lamina into the media.

Subacute aortic dissection – the period from 15 days to 90 days from the onset of symptoms of aortic dissection.

Aortic dissection – disruption of the medial layer of the aortic wall caused by the entry of blood into the wall, followed by separation/splitting of the aortic wall layers and the formation of a true lumen and false lumen with/without communication between them.

Malperfusion syndrome – impaired blood supply to organs and/or body parts (myocardial, cerebral, spinal, mesenteric, renal, or limb ischemia) resulting from dissection of the aorta and its branches.

Fenestration – a communication between the true and false lumens of a dissected aorta.

Chronic aortic dissection – a duration of more than 90 days from the onset of symptoms of aortic dissection, as well as in previously operated patients with type A aortic dissection and persistent dissection of the descending aorta.

Endoleak – persistent blood flow into the aneurysms sac after endovascular aneurysm repair (EVAR).

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Acute aortic syndrome (AAS) – life-threatening conditions involving a compromise of the structural integrity of the aortic wall. AAS includes aortic dissection (AD), intramural hematoma (IMH), and penetrating atherosclerotic ulcer (PAU), which can lead to aortic rupture.

Aortic dissection – defined as disruption of the medial layer of the aortic wall caused by intramural entry of blood, followed by separation/splitting of the aortic wall layers and the formation of a true lumen and false lumen with/without communication between them. In most cases, AD is caused by an intimal tear, allowing blood to enter the dissection plane – the media of the aorta. This is followed either by aortic rupture in the event of adventitial disruption or by re-entry of blood into the aortic lumen through a secondary intimal tear. AD can be antegrade or retrograde. Aortic dissection may also extend into its major branches. Other complications include cardiac tamponade, aortic regurgitation, and organ malperfusion syndrome. The inflammatory response to medial thrombosis can initiate further smooth muscle cell necrosis and apoptosis, as well as elastic tissue degeneration, thereby increasing the risk of medial rupture.

Intramural hematoma – the presence of blood within the medial layer of the aortic wall in the absence of a distinct intimal tear or a discernible false lumen. Blood may originate either from the rupture of the vasa vasorum, causing bleeding within the media, or from small intimal tears that are not visualized by standard imaging techniques. IMH is diagnosed using computed tomography angiography of the aorta (CTA), contrast-enhanced magnetic resonance angiography (MRA), and transthoracic echocardiography by demonstrating a circular or crescentic thickening of the aortic wall > 5 mm without evidence of blood flow.

Penetrating aortic ulcer – ulceration of an atherosclerotic plaque leading to a local defect in the aortic intima, which allows blood to penetrate into the medial layer and is frequently associated with an IMH of varying size. PAUs most commonly occur in the middle or distal portion of the descending thoracic aorta, less frequently in the aortic arch and abdominal aorta, and rarely in the ascending aorta.

Blunt traumatic aortic injury (BTAI) – disruption of the integrity of the aortic wall most commonly resulting from rapid deceleration due to a frontal or lateral collision, typically in high-speed motor vehicle accidents or falls from a height. Following traumatic brain injury, thoracic aortic trauma is the second most common cause of death in patients with blunt trauma; early mortality can exceed 80%. With improvements in care and rapid detection of BTAI, surviving patients are more likely to undergo successful surgical repair.

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

1.2.1 Aortic dissection

The etiology of aortic dissection is believed to be related to underlying weakness in the aortic media, exacerbated by an intimal tear, rupture of the vasa vasorum (intramural hematoma), or rupture of an atherosclerotic plaque/ulcer. The location of the primary entry tear and the extent of aortic propagation determine the clinical course of acute aortic dissection. Following the initial injury to the aortic wall at the intimal/medial level, propagation can occur proximally and/or distally. Although the primary entry tear can typically be assigned to a specific aortic segment, proximal/distal propagation and the extent of aortic involvement determine the classification of the disease (whether Stanford or DeBakey), its clinical course, and treatment.

Malperfusion occurs when a dissection compromises blood flow to a target organ. Distal propagation of the false lumen in the descending aorta can cause collapse of the true lumen, leading to malperfusion of the viscera, kidneys, spine, and/or limbs. "Malperfusion syndrome" refers to ischemia of target organs: visceral organs, kidneys, lower extremity vessels, brain, or spinal cord, manifesting as clinically recognizable pathophysiological changes (e.g., bowel ischemia with concomitant lactic acidosis). "Malperfusion" is defined as simply a reduction in blood flow to the arterial bed of a vital organ detected by clinical or instrumental examination (e.g., diminished/asymmetric limb pulse).

1.2.2 Traumatic aortic injury

The consequence of rapid deceleration is the application of torsional and shearing forces to relatively fixed segments of the aorta, such as the aortic root, the area near the ligamentum arteriosum, or the diaphragm. The combination of mediastinal compression and anterior displacement, a sharp rise in blood pressure, and stretching of the aorta along the spine may also explain the pathogenesis of BTAI. Accordingly, in BTAI, the injury is located at the aortic isthmus in 90% of cases.

1.3 Epidemiology of the Disease or Condition

1.3.1 Aortic dissection

Current epidemiological data on AD are sparse. According to the Oxford Vascular Study, the incidence of AD is estimated at 6 cases per 100,000 person-years. Incidence is higher in men and increases with age. The prognosis is worse in women due to atypical presentations and delayed diagnosis. The most common risk factor associated with AD is hypertension, which is observed in 65–75% of individuals. According to the IRAD registry, the mean age of patients is 63 years, and men account for 65%. Other risk factors include a history of aortic or aortic valve disease, a family history of aortic disorders, prior cardiac surgery, smoking, blunt chest trauma, and illicit drug use. According to autopsy data of victims killed in motor vehicle accidents, approximately 20% had an aortic rupture.

1.3.2 Intramural hematoma

Studies show that 5% to 25% of patients with suspected acute aortic syndrome have IMH. In the natural history of IMH, it resolves spontaneously in less than 10% of cases. Between 16% and 47% of IMH cases progress to aortic dissection if the intima tears and forms a communication with the aortic lumen.

1.3.3 Penetrating atherosclerotic ulcer

The true incidence of PAU is unknown, but is estimated to be 2% to 7% of all acute aortic syndrome cases. Typically, patients with PAU are older than 70 years compared to patients with classical aortic dissection, and they have a higher prevalence of multifocal atherosclerosis. Comorbidities include hypertension, tobacco use, chronic obstructive pulmonary disease, and renal failure. PAU may occur in younger patients, but often in the setting of connective tissue disease, with males affected more frequently than females. The natural history of PAU is not clearly defined, as they may remain stable, increase in size, or progress either to IMH, dissection, pseudoaneurysm, or aortic rupture. The risk of rupture reaches 40%. The optimal management strategy should be individualized based on the clinical presentation, imaging features of the PAU, and patient comorbidities.

1.3.4 Traumatic aortic injury

TRA is a rare traumatic lesion encountered in < 1% of patients with blunt trauma. Patients with TRA frequently have associated injuries such as rib fractures, intra-abdominal organ injuries, and cardiac complications that influence treatment decisions. Similar to TRA, abdominal aorta injuries are classified based on aortic contour defects, and this classification can be used to provide a framework for treatment and determination of the risk of severe morbidity and mortality from trauma. Because TRA is rare and symptoms are diverse, patient management must be approached on an individual basis. In general, patients with grade 1 aortic injuries can likely be managed with antihypertensive therapy, beta-blockers, and antithrombotic agents, if not contraindicated, with repeat computed tomography angiography of the aorta in 24-48 hours. Grade 2 injuries can also be managed nonoperatively, but they may progress to involve thrombosis or end-organ vascular rupture. For grade 3 injuries, endovascular treatment may be useful if anatomically feasible. Grade 4 injuries are more frequently accompanied by refractory hypotension, requiring rapid hemorrhage control, which can be performed in the emergency department (e.g., anterolateral thoracotomy with cross-clamping of the aorta) or the operating room. Whether open or endovascular means are used for TRA repair will depend on the patient's clinical status, hospital resources, and the practitioner's expertise.

1.4 Features of Coding the Disease or Condition

I71.0 – Aortic dissection (any part)

I72.1 – Aneurysm and dissection of upper extremity artery

Diagnosis formatting examples:

Primary diagnosis: Type 1(3) aortic dissection with formation of a thoracoabdominal aortic aneurysm.

Complications: Acute kidney injury. Chronic lower extremity ischemia, grade 2B.

1.5 Classification of the disease or condition

1.5.1 Aortic dissection

According to the DeBakey classification, there are three types of aortic dissection. Type I (approximately 50% of all dissections) - dissections originating in the ascending aorta and propagating at least to the aortic arch or distally; Type II (35%) - originating in and confined to the ascending aorta (proximal to the brachiocephalic trunk); Type III - originating distal to the left subclavian artery and propagating distally.

Stanford type A aortic dissection involves the ascending aorta (proximal to the brachiocephalic trunk) regardless of the site of the primary entry tear, which is also considered DeBakey type I / type II aortic dissection (depending on the distal extent of the dissection).

Temporally, aortic dissections are classified into: acute aortic dissection (< 14 days), subacute aortic dissection (15–90 days), and chronic aortic dissection (> 90 days).

1.5.2 Intramural hematoma

• Type A intramural hematoma

• Type B intramural hematoma

1.5.3 Penetrating atherosclerotic ulcer

• Penetrating atherosclerotic ulcer with intramural hematoma (ruptured and non-ruptured)

• Isolated penetrating atherosclerotic ulcer

1.5.4 Traumatic aortic injury

TRA classification (see Appendix A3):

• Type I - intimal tear,

• Type II - IMH,

• Type III - pseudoaneurysm,

• Type IV - rupture.

1.6 Clinical presentation of the disease or condition

Chest pain is the most common symptom of acute aortic dissection. Sudden-onset severe chest and/or back pain is most typical. The pain may be sharp, tearing, or knife-like and generally differs from other causes of chest pain; its sudden onset is its most specific characteristic. The most frequent pain location is the chest (80%), while back or abdominal pain occurs in 40% and 25% of cases, respectively. Anterior chest pain is more commonly associated with type A aortic dissection, whereas patients with type B dissection more frequently present with back or abdominal pain. The clinical manifestations of the two types of aortic dissection often overlap.

Pulse deficit may occur in 30% of patients with type A aortic dissection and 15% with type B. Severe lower extremity ischemia is rare. Blood pressure discrepancies between the right and left brachial arteries may also be noted when the dissection extends into the arch branches.

Aortic regurgitation may accompany 40–75% of cases of aortic dissection. Following acute aortic rupture, aortic valve regurgitation is the second most common cause of death in patients with aortic dissection. Patients with acute severe aortic regurgitation typically develop heart failure and cardiogenic shock.

Aortic regurgitation in aortic dissection results from dilation of the aortic root and aortic valve annulus, rupture of the annulus or valve cusps, displacement of one of the cusps below the line of valve closure, lack of cusp coaptation, and the physical impact of the dissected intima on aortic valve closure. Cardiac tamponade is observed in 20% of patients with acute type A aortic dissection and is associated with a doubled mortality rate.

Myocardial ischemia and infarction may develop in 10–15% of patients with aortic dissection and result from dilation of the aortic false lumen with subsequent compression or occlusion of the coronary artery ostia, or propagation of the dissection into the coronary arteries.

Chronic heart failure in the setting of aortic dissection is usually associated with aortic regurgitation. More commonly identified in type A aortic dissection, heart failure may also occur in patients with type B aortic dissection due to myocardial ischemia, pre-existing diastolic dysfunction, or uncontrolled arterial hypertension.

Massive hemothorax resulting from aortic bleeding into the mediastinum and pleural cavity is relatively rare, as these patients generally do not survive to hospital admission. A small hemothorax may be detected in 15–20% of patients with aortic dissection, with an almost equal distribution between type A and type B dissections. Hemothorax is thought to be primarily a consequence of an inflammatory process.

Pulmonary complications of acute aortic dissection are rare and include compression of the pulmonary artery and formation of an aortopulmonary fistula, leading to dyspnea or unilateral pulmonary edema, as well as acute rupture of the aorta into the lung with massive hemoptysis.

Syncope is an important initial symptom of aortic dissection, occurring in approximately 15% of patients with type A aortic dissection and 5% with type B. This symptom is associated with an increased risk of in-hospital mortality because it is frequently accompanied by life-threatening complications such as cardiac tamponade or dissection of the aortic arch branches. Consequently, clinicians should actively screen for these complications in patients with suspected aortic dissection presenting with syncopal episodes.

Neurological symptoms can often be dramatic and dominate the clinical picture, masking the underlying disease. They may be caused by cerebral malperfusion, hypotension, thromboembolism, as well as compression of peripheral nerves. The incidence of neurological symptoms in aortic dissection ranges from 15–40%, and in half of the cases, they are transient. Acute paraplegia due to spinal cord ischemia caused by occlusion of spinal arteries is uncommon, may be painless, and can lead to a misdiagnosis of Leriche syndrome. Hoarseness due to compression of the left recurrent laryngeal nerve is rarely observed.

Mesenteric ischemia occurs in < 5% of patients with type A aortic dissection. Clinical manifestations are diverse because abdominal pain is often nonspecific, and pain is absent in 40% of cases. As a result, the diagnosis—which enables timely and appropriate life-saving treatment—is frequently delayed. In-hospital mortality in patients with mesenteric malperfusion is nearly 3 times higher than in patients without this complication (63% vs. 24%). Gastrointestinal bleeding is a rare but potentially fatal complication. Bleeding may be limited due to bowel infarction, or massive, caused by an aorto-esophageal fistula or rupture of the aortic dissection into the small intestine.

Renal failure may present at disease onset or manifest during the hospital stay in up to 20% of patients with acute type A aortic dissection and in approximately 10% of patients with type B aortic dissection. It may result from renal hypoperfusion or renal infarction due to involvement of the renal arteries in the dissection process, or develop secondary to prolonged hypotension. Early detection of this condition requires serial blood creatinine testing and urine output monitoring.

2. Diagnostics, medical indications and contraindications for diagnostic methods

Criteria for establishing the disease or condition.

The diagnosis of aortic dissection is suspected during a cardiac examination, targeted chest radiography, and electrocardiography, and is confirmed by computed tomography angiography of the aorta.

2.1 Complaints and Anamnesis

• All patients with suspected aortic dissection are recommended to undergo symptom evaluation and medical history taking to verify the diagnosis and select the optimal management strategy [1].

(CRA C, LOR 4).

Comments. Although the classic textbook description of acute aortic syndrome is sudden or "tearing" pain, patients more frequently report the abrupt onset of severe "sharp" or "stabbing" pain in the chest or back (and occasionally the abdomen) that peaks in intensity at onset and may occasionally radiate. Depending on the extent of aortic involvement, patients may experience various additional symptoms. A thorough, detailed medical and family history (including a history of aortic aneurysms, genetic aortopathies, aortic dissection, or sudden death) is critical for establishing the diagnosis.

Although aortic diseases may be asymptomatic in many cases, a wide spectrum of symptoms can potentially be associated with various aortic lesions:

— acute, severe, aching, or throbbing pain in the chest or abdomen that may radiate to the back, buttocks, groin, or legs, suggesting aortic dissection or another acute aortic syndrome, best described as a "tearing sensation";

— cough, dyspnea, or difficult or painful swallowing in large thoracic aortic aneurysms;

— constant or intermittent abdominal pain or discomfort, a pulsatile sensation in the abdomen, or a feeling of "fullness" after minimal food intake in large abdominal aortic aneurysms;

— stroke, transient ischemic attack, or claudication due to aortic atherosclerosis;

— hoarseness due to left recurrent laryngeal nerve palsy in rapidly progressive lesions.

The history evaluation should aim to thoroughly understand the patient's complaints, identify personal risk factors for cardiovascular disease, and review the family history of arterial diseases, particularly the presence of aneurysms, aortic dissection, or sudden death.

2.2 Physical Examination

(CRA C, LOR 4).

Comments: in some cases, physical examination may reveal abnormal arterial pulsation or turbulent blood flow, and peritoneal signs due to mesenteric ischemia. It is also necessary to compare blood pressure on both upper extremities and assess pulses in the brachiocephalic arteries and lower extremities.

Blood pressure must be measured in both arms and both lower extremities to detect or rule out a blood pressure discrepancy resulting from acute aortic syndrome. Auscultation (of heart and pericardial pathology) may reveal a murmur typical of aortic stenosis, potentially indicating underlying bicuspid aortic valve, or aortic regurgitation, which frequently accompanies type A aortic dissection.

2.3 Laboratory Diagnostics

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

2.4 Instrumental Diagnostics

• Patients with aortic dissection are recommended to undergo resting electrocardiography (ECG), including recording, analysis, and interpretation of 12-lead ECG data to assess heart rhythm, detect QRS complex abnormalities, and identify arrhythmias and conduction disturbances, as well as in the peri- and/or postoperative period when indicated for surgical treatment [34].

(CRA C, LOR 4).

• Patients with suspected aortic dissection are recommended to undergo echocardiography as an initial imaging study [2–3].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

Comments: transthoracic echocardiography is insufficient for detecting acute aortic IMH due to its low sensitivity. The borderline limit for IMH is 5 mm, and the sensitivity of transthoracic echocardiography for its detection is less than 40%. Consequently, transthoracic echocardiography cannot be used as the sole imaging modality in patients with suspected AAS. Contrast-enhanced computed tomography angiography of the aorta and contrast-enhanced magnetic resonance angiography are the leading methods for diagnosing and classifying intramural hematoma. When evaluating the condition of the aorta using computed tomography angiography of the aorta, non-contrast images are of decisive importance for diagnosing IMH. A high-density crescentic aortic thickening extending in a longitudinal, non-spiral plane is a hallmark of this pathology. Unlike AD, the aortic lumen is rarely narrowed in the presence of IMH, and after contrast administration, intimal flaps are not visualized, nor is there enhancement of the aortic wall. The use of computed tomography angiography of the aorta combining unenhanced and contrast-enhanced images in the diagnosis of IMH provides a sensitivity of up to 96%. Occasionally, on computed tomography angiography of the aorta, it may be difficult to differentiate IMH from atherosclerotic aortic thickening, thrombotic masses, or thrombosed dissection. Under these circumstances, contrast-enhanced magnetic resonance angiography can be a valuable method to resolve these issues, as it also makes it possible to determine the timing of hematoma development based on the signal characteristics of various hemoglobin degradation products. In acute type A and B IMH, images must be carefully analyzed to attempt to localize the primary entry tear, which is very frequently present and therefore can assist in choosing the treatment method, especially when discussing the possibility of TEVAR.

On unenhanced computed tomography angiography of the aorta, PAU resembles IM. Computed tomography angiography of the aorta, including the use of axial and multiplanar reformations, is the method of choice for diagnosing PAU. A characteristic sign is a localized ulceration penetrating through the aortic intima into the wall in the middle and distal thirds of the descending thoracic aorta. Local thickening or marked signal intensity reduction from the adjacent neighboring aortic wall suggests the presence of an associated IMH. In this regard, a potential disadvantage of contrast-enhanced magnetic resonance angiography is its inability to detect the displacement of intimal calcifications, which frequently accompanies PAU.

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

In the case of an initially negative instrumental test result in patients with persistent suspicion of AAS, it is recommended to perform repeat computed tomography angiography of the aorta to reduce potential complications after 6 months [168].

• In patients with suspected AD for initial diagnostic imaging, it is recommended to perform computed tomography angiography of the aorta, computed tomography angiography of the brachiocephalic arteries, and computed tomography angiography of the lower extremity vessels to verify the diagnosis [2–6].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

Comments: during panaortography, the diagnosis of AD is based on 'direct' angiographic signs, such as visualization of an intimal flap (a negative, often mobile linear image) or identification of two separate lumens in the aorta. 'Indirect' signs include aortic contour irregularities, rigidity or compression, aortic branch anomalies, aortic wall thickening, and aortic regurgitation. Panaortography is no longer used to diagnose AD, except during coronary angiography or endovascular intervention.

• For initial diagnostic imaging in patients with suspected AAS as an alternative study, taking risks into account, it is recommended to perform transesophageal echocardiography and contrast-enhanced magnetic resonance angiography [2–7].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

Comments: although the sensitivity and specificity of computed tomography angiography of the aorta, contrast-enhanced magnetic resonance angiography, and transesophageal echocardiography are quite high, computed tomography angiography of the aorta has become the preferred method for evaluating most patients with suspected AAS. The 'gold standard' is ECG-gated MSCT panaortography, capturing the brachiocephalic and common femoral arteries in the scan range.

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

• In patients with type B AD undergoing conservative treatment, it is recommended to perform repeat imaging studies (computed tomography angiography of the aorta or contrast-enhanced magnetic resonance angiography) within 24–48 hours after the initial study to reduce potential complications [171, 173].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

• In patients with suspected PAAS, it is recommended to perform computed tomography angiography of the aorta to determine further surgical tactics [117].

(LoE C, GoR 4).

• In patients with suspected PAAS, if computed tomography angiography of the aorta is unavailable, it is recommended to perform transesophageal echocardiography for the differential diagnosis of PAAS [118–119].

(CQR C, LVE 2).

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

(CRA C, LOR 4).

2.5 Other Procedures

No.

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

3.1 Conservative Treatment

3.1.1 Medical therapy in the acute stage of dissection

• In all patients with AAS, it is recommended to administer medical therapy, including pain management (intravenous morphine** (group N02AA – natural opium alkaloids; syn.: narcotic analgesics)) and blood pressure stabilization for impulse-control therapy (intravenous beta-blocker (predominantly metoprolol**)) [172, 173].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

Comments: in addition to pain relief, morphine** helps reduce fear and agitation, decreases sympathetic activity, increases vagal tone, reduces the work of breathing, and causes dilation of peripheral arteries and veins (the latter being especially important in pulmonary edema). The dose required for adequate pain relief depends on individual sensitivity, age, and body size. Before use, 10 mg of morphine** is diluted in at least 10 ml of 0.9% sodium chloride solution** (group B05BB – solutions affecting the water-electrolyte balance). Initially, 2–4 mg of the medicinal product should be administered intravenously and slowly. If necessary, administration is repeated every 5–15 minutes with 2–4 mg until pain relief is achieved or side effects occur that preclude increasing the dose.

When using morphine**, the following complications are possible:

• severe arterial hypotension; resolved by placing the patient in a horizontal position combined with elevating the legs (in the absence of pulmonary edema). If this is insufficient, 0.9% sodium chloride solution** is administered as an IV drip. In rare cases, adreno- and dopaminergic stimulants (group C01CA – adrenergic and dopaminergic agents);

• severe bradycardia combined with arterial hypotension; reversed with atropine** (IV 0.5–1.0 mg);

• nausea, vomiting; reversed with phenothiazine derivatives, specifically metoclopramide** (IV single dose 10 mg);

• marked respiratory depression; reversed by naloxone** (IV 0.1–0.2 mg, repeated every 15 minutes if necessary), which also reduces the analgesic effect of the drug.

Opiates can weaken intestinal peristalsis and lead to constipation. Drugs of this group reduce bladder tone and cause urinary retention, especially in men with prostatic hyperplasia.

Metoprolol must be administered intravenously and slowly under ECG and blood pressure monitoring in 5 mg increments every 2 minutes up to a maximum dose of 15 mg; if well tolerated, 15 minutes after the last IV administration, oral administration of up to 50 mg every 6 hours for 48 hours.

• In patients with uncomplicated type B AD, medical therapy (analgesic and impulse-control therapy) should always be recommended to reduce potential complications [3].

(CRA C, LOR 4).

Comments: the drug therapy regimen is described in the first recommendation of section 3.1.1.

• In patients admitted to the hospital with AAS, as initial therapeutic measures aimed at reducing load on the aortic wall, it is recommended in the first hours of admission to the intensive care unit to prescribe impulse-control therapy and measure blood pressure in peripheral arteries using an arterial catheter to reduce the progression of AAS [2–6].

(LoE C, GoR 4).

Comments: the drug therapy regimen is described in the first recommendation of section 3.1.1.

• In patients with acute aortic syndrome (AAS), intravenous beta-blockers are recommended as part of initial treatment (unless contraindicated) to lower heart rate and SBP (target SBP 100–120 mmHg, target heart rate <60 bpm) [172].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

Comments: the drug therapy regimen is described in the first recommendation of section 3.1.1.

• In patients with contraindications to or intolerance of beta-blockers, it is recommended to initiate treatment with intravenous calcium channel blockers (verapamil** (diltiazem can be used if hypertension is present)) to achieve heart rate control [172].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

Comments: verapamil**, diltiazem (group C08DA – phenylalkylamine derivatives) or amlodipine** (group C08CA – dihydropyridine derivatives) may be used if hypertension cannot be controlled by other means. Diltiazem or verapamil** may be considered for heart rate control when beta-blockers cannot be used, and less frequently for terminating supraventricular tachyarrhythmias. In patients with persistent myocardial ischemia when beta-blockers are insufficiently effective, contraindicated, or cause unacceptable complications, the addition of long-acting dihydropyridine derivatives may be considered. Concomitant administration of verapamil** and diltiazem with beta-blockers is generally discouraged due to the cumulative risk of adverse effects.

• If patients with AAS have inadequate blood pressure control after the initiation of intravenous beta-blocker therapy, it is recommended to add intravenous administration of peripheral vasodilators (nitroglycerin**) to initial treatment to normalize blood pressure [173].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

Comments: nitroglycerin: intravenous infusion at 5–166 mcg/min; usually starting at 10–20 mcg/min with possible increases of 5–10 mcg/min every 5–10 min until symptoms subside and/or systolic blood pressure decreases by 10–15% in initially normotensive patients and by 25–30% in hypertension (but not below 95 mmHg).

The criterion for an adequately adjusted infusion rate (dose) during IV nitrate infusion is the systolic blood pressure level, which should be reduced by 10–15% in normotensive individuals and by 25–30% in hypertensive individuals, but not below 100 mmHg. The usual initial infusion rate of nitroglycerin** is 10 mcg/min. If ineffective, the infusion rate is increased by 10–15 mcg/min every 5–10 min until the desired effect is achieved. If the target blood pressure reduction cannot be reached even after increasing the nitroglycerin infusion rate to 166 mcg/min, further dose escalation is pointless. The optimal duration of nitrate infusion is no more than 24–48 hours, as tolerance frequently develops thereafter. If hypotension occurs, discontinuing the nitroglycerin** infusion is usually sufficient due to the drug's short half-life. Standard measures to increase venous return to the heart are less frequently required (elevating the lower extremities; intravenous administration of 0.9% sodium chloride** solution, use of adrenergic and dopaminergic stimulants may be considered). Organic nitrates are not recommended in arterial hypotension, right ventricular myocardial infarction, as well as after taking sildenafil or vardenafil within the preceding 24 hours, or tadalafil within the preceding 48 hours, due to a high risk of complications. Analgesics and caffeine-containing medications can be used for headaches.

• In the presence of hypotension in patients with AAS, it is recommended to restore circulating blood volume until an SBP of 90 mmHg is reached to reduce the risk of neurological complications and mortality [172].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

Comments: in patients with AAS and polytrauma, a multidisciplinary approach is essential to correctly determine the timing of interventions and treatment priorities. Aggressive fluid administration should be avoided as it may exacerbate bleeding, coagulopathy, and hypertension; to reduce the risk of aortic rupture, the mean arterial pressure should not exceed 90 mmHg.

• To improve hemodynamic control in patients with AAS, it is recommended to provide adequate analgesia as needed [5].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

Comments: the drug therapy regimen is described in the first recommendation of section 3.1.1.

• Optimal medical therapy is recommended to reduce the risk of potential complications (aortic rupture, visceral malperfusion, acute cerebrovascular accident, critical lower limb ischemia, acute renal failure, acute myocardial infarction) in patients with uncomplicated type B aortic dissection and retrograde dissection resulting from a tear at or distal to the left subclavian artery, provided that the retrograde dissection is confined to the aortic arch [30].

(LoE C, GoR 4).

Comments: the drug therapy regimen is described in the first recommendation of section 3.1.1.

• In patients with hemopericardium due to acute type A aortic dissection and imminent cardiac arrest, pericardiocentesis within the first hour after detection may be recommended to relieve tamponade and restore adequate organ perfusion [36].

(LoE C, GoR 4).

3.1.2 Long-term medical therapy

• Patients with aortic dissection are recommended lifelong treatment with beta-blockers (unless contraindicated) to achieve heart rate and blood pressure control in order to reduce the likelihood of long-term adverse events related to aortic pathology [173].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

3.1.3 Intramural hematoma

• In patients with uncomplicated acute type B intramural hematoma, conservative therapy is recommended as the initial treatment strategy to reduce the risk of disease progression [9,158,73,162].

(LoE C, GoR 4).

3.1.4 Traumatic aortic injury

• In patients with type 1 blunt aortic injury (BAI), conservative treatment with dynamic monitoring and evaluation is recommended to improve long-term survival [114, 121].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

Comments: conservative treatment includes pain management and anti-impulse therapy with/without the administration of peripheral vasodilators (see section 3.1.1). Dynamic monitoring and evaluation include: repeat computed tomography angiography of the aorta within 24–48 hours after the initial scan, blood total hemoglobin testing, general clinical blood chemistry panel, and urine output measurement.

• In patients with type 2 blunt aortic injury without high aortic risk, conservative treatment with dynamic monitoring and evaluation may be recommended to prevent subsequent complications [122, 123].

(LoE C, GoR 4).

Comments: for the dynamic monitoring regimen and conservative treatment, see the previous recommendation.

• In patients with grade 1–2 blunt aortic injury without malperfusion, antihypertensive therapy is recommended (see section 3.1.1), if clinically tolerated, along with repeat computed tomography angiography of the aorta within 24–48 hours after the initial scan to reduce the risk of injury progression [166].

(CRA C, LOR 4).

3.2 Surgical Treatment

3.2.1 Acute type A aortic dissection (see Appendix B):

• In patients with acute aortic syndrome requiring urgent surgical intervention (within 24 hours of diagnosis), decisions regarding the method and management strategy are recommended to be made by a Multidisciplinary Aortic Team [37–40].

(CRA C, LOR 4).

Comments: patients with acute aortic dissection who are candidates for either surgical or endovascular treatment modalities, as well as patients with comorbid conditions, should be referred to expert centers performing at least 30–40 procedures per year. The Multidisciplinary Aortic Team may include a cardiologist, cardiovascular surgeon, anesthesiologist, and critical care physician.

• In patients with acute type A aortic dissection, prompt evaluation regarding surgical intervention is recommended to reduce the risk of potential complications and mortality [37–40].

(CRA C, LOR 4).

Comments: surgical triage is based on clinical findings and computed tomography angiography of the aorta and/or transthoracic echocardiography, focusing on:

1) Identification of aortic rupture or intramural hematoma,

2) Location of the primary entry tear,

3) Proximal and distal extent of the false lumen,

4) Radiological signs of malperfusion or rupture.

Clinical findings are compared with imaging data to verify complications of acute type A aortic dissection (AAD), such as cardiac tamponade, aortic regurgitation, malperfusion syndrome, or shock. The traditional management strategy for acute type A aortic dissection with malperfusion syndrome involves intervention on the thoracic aorta within 24 hours to restore the true lumen and normalize blood flow in the true lumen of the aortic branches, while peripheral revascularization is deferred to a subsequent stage in case of persistent end-organ ischemia (at 3 months and no later than 1 year). An alternative strategy in stable patients with acute type A aortic dissection and malperfusion syndrome involves the reverse order of actions, consisting of staged endovascular or surgical revascularization followed by open surgical repair of the thoracic aorta [60-65]. This approach aims to resolve malperfusion syndrome, reduce operative risk during subsequent thoracic aortic surgery, and improve overall survival. However, this strategy carries a risk of aortic rupture because proximal aortic repair is necessarily delayed, making an individualized approach essential. Hybrid strategies allow simultaneous management of visceral malperfusion and proximal aortic replacement [70].

• In patients with acute type A aortic dissection and cerebral malperfusion, surgical treatment is recommended to improve long-term survival [50-56].

(LoE C, GoR 4).

• Conservative management may be recommended in patients with catheter-induced acute type A aortic dissection, provided it does not extend beyond the aortic root, to reduce the likelihood of long-term adverse events [57-59].

(LoE C, GoR 4).

Comments. Iatrogenic aortic dissection (IAD) may occur during coronary interventions, cardiac surgery, endovascular treatment of aortic coarctation [132,133], aortic stent-grafting [134], peripheral interventions, intra-aortic balloon counterpulsation, and transcatheter aortic valve implantation [135]. IAD is a rare complication, occurring in less than 4 cases per 10,000 coronary angiographies and less than 2 per 1,000 percutaneous coronary interventions [135-139]. As a rule, IAD is easily detected during coronary angiography and is characterized by contrast medium stagnation at the aortic root level or in the ascending aorta.

The management of patients with catheter-induced IAD is not standardized. A conservative approach is frequently employed, particularly in catheter-induced dissection of the abdominal aorta or iliac arteries, as well as in cases where the dissection is located at the level of the aortic valve cusps. Although IAD of the right coronary artery ostium may cause blood flow impairment in this artery and require emergency PCI, the outcome is benign if the complication is promptly recognized and further contrast administration is withheld. Management is conservative, with complete spontaneous healing in most cases. Aortic ruptures are extremely rare, but individual reports of extensive secondary type A dissections require careful monitoring of these patients.

Dissection extending several centimeters into the ascending aorta or beyond will likely require emergency surgery.

• In a number of patients with retrograde acute type A aortic dissection, it is recommended to consider isolated thoracic endovascular aortic repair (TEVAR) to reduce the probability of complications [60-61].

(CRA C, LOR 4).

• In patients with acute type A aortic dissection complicated by mesenteric malperfusion, thoracic aortic surgery should be delayed to assess the viability of ischemic visceral organs [60-65].

(LoE C, GoR 4).

• In patients with acute type A aortic dissection complicated by mesenteric malperfusion, it is recommended to consider thoracic endovascular aortic repair with stent-graft fenestration and stenting of the visceral branches to reduce the likelihood of adverse gastrointestinal complications [63,66].

(LoE C, GoR 4).

• Prior to thoracic aortic surgery in patients with acute type A aortic dissection, it is recommended to consider restoring blood flow in the ischemic limb before proximal aortic intervention in stable patients, or to take measures to preserve perfusion (limb perfusion during cardiopulmonary bypass, fenestration, stenting, etc.) during emergency intervention (tamponade, acute aortic regurgitation, etc.) to reduce the risk of acute limb ischemia and subsequent complications [67-69].

(LoE C, GoR 4).

• In patients with acute type A aortic dissection with a partially dissected root without significant aortic valve pathology, aortic valve repair under cardiopulmonary bypass (valve resuspension) is recommended rather than valve replacement to improve long-term survival [75-79].

(Reliability of Evidence Level B, Consistency of Evidence Level 2).

• In patients with acute type A aortic dissection with significant root involvement, root aneurysm, or aortic dysplasia, aortic root replacement is recommended to reduce mortality [80-83].

(LoE C, GoR 4).

• In stable patients with acute type A aortic dissection, it is recommended to consider aortic valve-sparing ascending aorta reconstruction performed by experienced surgeons within a multidisciplinary aortic team to improve long-term survival [84-85].

(Reliability of Evidence Level B, Consistency of Evidence Level 2).

• During ascending aorta replacement in patients with acute type A aortic dissection, creation of an "open" distal anastomosis is recommended to improve long-term outcomes (survival, false lumen thrombosis) [86-89].

(CRA C, LOR 4).

• In patients with acute type A aortic dissection without primary intimal tears in the aortic arch and without significant aortic dilatation, preference should be given to partial arch replacement instead of total arch replacement to improve long-term outcomes [90-92].

(Reliability of Evidence Level B, Consistency of Evidence Level 2).

• When dissection extends into the descending aorta in patients with acute type A aortic dissection, it is recommended to consider extended aortic resection with replacement and antegrade stent-grafting of the proximal descending thoracic aorta to reduce malperfusion and the risk of late distal aortic complications [93-94].

(CRA C, LOR 4).

3.2.1.1 Perfusion and cannulation strategies in acute type A aortic dissection

• Whenever feasible, axillary cannulation is recommended over femoral cannulation in patients with acute type A aortic dissection undergoing surgery, to reduce the risk of cerebral complications or retrograde malperfusion [101-102].

(Reliability of Evidence Level B, Consistency of Evidence Level 2).

• In patients with acute type A aortic dissection undergoing surgery requiring circulatory arrest, continuous monitoring of cerebral tissue oxygen saturation is recommended to improve neurological outcomes [103-105].

(CRA C, LOR 4).

• As an alternative to axillary or femoral cannulation in patients with acute type A aortic dissection, cannulation of the true aortic lumen or the brachiocephalic vessels may be recommended to adhere to the principle of maximum safety [106-111].

(CRA C, LOR 4).

Comments: the cannulation strategy should be based on the principle of maximum safety while taking into account the type of dissection. Various combinations of methods may be used.

3.2.2 Acute type B dissection (complicated) (see Appendix B):

• Thoracic endovascular aortic repair (TEVAR) is recommended for patients with complicated hyperacute, acute, or subacute conditions presenting with rupture and/or malperfusion and favorable anatomy for TEVAR, to reduce the resulting complications [6].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

(Reliability of Evidence Level B, Consistency of Evidence Level 2).

• Fenestration (transluminal balloon aortic angioplasty) may be recommended for patients with complicated hyperacute, acute, or subacute aortic dissection to mitigate the consequences of complications [4-8].

(CRA C, LOR 4).

3.2.3 Acute type B dissection (uncomplicated) (see Appendix B):

• In patients with acute uncomplicated type B aortic dissection and high-risk features, it is recommended to consider treatment (from 24 hours to 90 days) using thoracic endovascular aortic repair (TEVAR) to reduce early adverse events and improve long-term outcomes [18-21].

(LoE C, GoR 4).

Comments: the natural history of type B aortic dissection is often uncomplicated; therefore, in the absence of malperfusion or early signs of disease progression, the patient's condition can be stabilized with isolated medical therapy, controlling pain and blood pressure.

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

3.2.4 Chronic type B dissection (see Appendix B):

(Reliability of Evidence Level B, Consistency of Evidence Level 2).

Comments: patients with chronic type B aortic dissection complicated by progressive thoracic aorta enlargement (> 10 mm/year), penetrating atherosclerotic ulcer of an aneurysm (with a total aortic diameter > 60 mm), malperfusion syndrome, or recurrent pain syndrome require TEVAR or open surgical treatment (aortic resection with replacement and branch reconstruction, aortic resection with replacement, aortic patch angioplasty). Optimal treatment for patients with chronic aortic dissection remains unclear. There are no randomized comparisons between TEVAR and conventional open surgery (aortic resection with replacement and branch reconstruction, aortic resection with replacement, aortic patch angioplasty). Thoracic endovascular aortic repair can be used to exclude an aneurysm, which is usually located in the distal aortic arch, and to prevent its rupture; however, aortic remodeling cannot be expected due to the thickened, rigid intima. Small case series have demonstrated that TEVAR is feasible in patients with descending thoracic aortic aneurysm secondary to chronic aortic dissection, with acceptable mid-term outcomes. Complete aortic remodeling was observed in only 36% of patients following TEVAR. Descending aortic surgery is associated with a high operative risk. The increasingly popular open aortic arch replacement with antegrade stenting of the descending thoracic aorta (“frozen elephant trunk” technique) may become an optimal alternative for selected patients.

• TEVAR (thoracic endovascular aortic repair) is recommended for patients with chronic type B aortic dissection with suitable anatomy (adequate landing zone, no ascending aorta or aortic arch aneurysm) and high risk of complications from open reconstructive surgery (aortic resection with replacement and branch reconstruction, aortic resection with replacement, aortic patch angioplasty) due to comorbidities, to reduce early adverse events and improve long-term outcomes [12-13].

(LoE C, GoR 4).

• Isolated TEVAR (thoracic endovascular aortic repair) as a standalone therapy is not recommended for patients with chronic type B aortic dissection who have a large abdominal aortic aneurysm, inadequate distal landing zone, and/or large distal fenestrations, in order to reduce early adverse events [14-17].

(CRA C, LOR 4).

• For patients with connective tissue disorders and type B aortic dissection who experience disease progression despite optimal medical therapy, it is recommended to perform open surgical intervention (aortic resection with replacement and branch reconstruction, aortic resection with replacement, aortic patch angioplasty) to improve long-term survival [171].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

• TEVAR (thoracic endovascular aortic repair) is recommended for patients with connective tissue disorders presenting with acute complicated type B aortic dissection and anatomy favorable for TEVAR as a bridge to delayed open reconstructive surgery (aortic resection with replacement and branch reconstruction, aortic resection with replacement, aortic patch angioplasty) to improve long-term survival [171].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

• To reduce the risk of spinal cord ischemic injury in patients with aortic dissection undergoing TEVAR (thoracic endovascular aortic repair) that blocks the antegrade blood flow of the left subclavian artery, it is recommended to perform preliminary revascularization of the left subclavian artery (carotid-subclavian bypass, subclavian artery stenting) [171].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

3.2.5 Intramural hematoma

• In patients with complicated acute intramural hematoma (IMH) of the aorta type A or B, it is recommended to perform urgent surgical intervention (within 24 hours) to reduce mortality [9,158,73].

(CRA C, LOR 4).

Comments: signs of complicated IMH include malperfusion, periaortic hematoma, pericardial effusion with cardiac tamponade, persistent, refractory, or recurrent pain syndrome, and rupture.

• In patients with uncomplicated acute type A IMH, it is recommended to perform immediate open surgery within up to 3 days (aortic resection with replacement and branch reconstruction, aortic resection with replacement) to reduce the likelihood of adverse complications [9,159-161].

(Reliability of Evidence Level B, Consistency of Evidence Level 3).

• Emergency surgical intervention is recommended for patients with type A IMH in the presence of risk factors (aortic diameter greater than 50 mm, hematoma thickness greater than 11 mm, hemopericardium, aortic regurgitation, aortic wall ulceration) to reduce mortality [43-44].

(LoE C, GoR 4).

Comments: emergency surgical treatment is indicated in complicated cases involving pericardial effusion, periaortic hematoma, or large aneurysm, while urgent surgery (< 24 h after diagnosis) is required for most type A IMHs. In elderly patients with severe comorbidities, an initial conservative “wait-and-watch” approach (optimal medical therapy with blood pressure control, pain management, and serial imaging) may be a reasonable option, especially in the absence of aortic dilatation (< 50 mm) and an IMH thickness < 11 mm.

• A watchful waiting strategy is recommended for patients with type A IMH and significant comorbidities in the absence of aortic risk factors to reduce early adverse events and improve long-term outcomes [45-49].

(LoE C, GoR 4).

• In patients with type B IMH requiring surgical treatment of the distal aortic arch or descending thoracic aorta (aortic resection with replacement and branch reconstruction, aortic resection with replacement, aortic patch angioplasty) with suitable anatomy, the use of TEVAR (thoracic endovascular aortic repair) is recommended if performed by surgeons experienced in endovascular surgery, to reduce early adverse events and improve long-term outcomes [158,163].

(Reliability of Evidence Level B, Consistency of Evidence Level 2).

Comments: medical therapy is the primary approach for type B IMH. Indications for endovascular treatment or open surgery are the same as for type B aortic dissection. A subgroup of patients with aortic enlargement or ULP should be carefully evaluated, and in case of persistent or recurrent symptoms, or progressive aortic enlargement, surgical treatment is indicated. Indications for intervention in the acute phase include IMH expansion despite medical therapy and intimal rupture according to computed tomography angiography of the aorta, with TEVAR being preferred over open surgery.

• In patients with type B IMH who require surgical treatment of the distal aortic arch or descending thoracic aorta and have anatomical features unfavorable for endovascular surgery, it is recommended to perform open surgery (aortic resection with replacement and branch reconstruction, aortic resection with replacement) to improve long-term outcomes [73,158].

(LoE C, GoR 4).

• In patients with uncomplicated type B IMH who have high-risk imaging features, it is recommended to perform TEVAR (thoracic endovascular aortic repair) to reduce early adverse events and improve long-term outcomes [162,165].

(CQR C, LVE 2).

3.2.6 Penetrating atherosclerotic ulcer

• For patients with penetrating atherosclerotic ulcer (PAU) with aortic rupture or PAU of the ascending aorta with IMH, it is recommended to promptly (within 3 days of diagnosis) address the need for surgical intervention (aortic resection with replacement and branch reconstruction, aortic resection with replacement, aortic endografting) to reduce mortality [71-73,173].

(LoE C, GoR 4).

• In patients with penetrating aortic ulcer of the ascending aorta associated with intramural hematoma, urgent surgical intervention is recommended to reduce the risk of mortality [9,73,158,173].

(LoE C, GoR 4).

• In patients with penetrating aortic ulcer of the aortic arch or descending thoracic aorta with associated intramural hematoma, the question of surgical intervention should be considered in a short timeframe (up to 3 days after diagnosis) to reduce the likelihood of adverse complications [71-73,173].

(LoE C, GoR 4).

• In patients with penetrating aortic ulcer of the abdominal aorta associated with intramural hematoma, urgent surgical intervention (up to 3 days after diagnosis) (aortic resection with grafting and branch plasty, aortic resection with grafting, endovascular aortic repair) may be recommended to reduce the risk of mortality [159,173].

(LoE B, GoR 3).

• In symptomatic patients with isolated penetrating aortic ulcer and recurrent pain syndrome correlating with imaging findings, urgent surgical intervention (aortic resection with grafting and branch plasty, aortic resection with grafting, endovascular aortic repair) is recommended to reduce the likelihood of adverse complications [71-73,173].

(CRA C, LOR 4).

• In asymptomatic patients with isolated penetrating aortic ulcer who are at high risk for aortic complications (maximum ulcer diameter equal to or greater than 13–20 mm, maximum depth equal to or greater than 10 mm (see Appendix A3), significant progression of ulcer diameter or depth over time, combination of penetrating aortic ulcer with a saccular aneurysm or increasing pleural effusion), surgical intervention (aortic resection with grafting and branch plasty, aortic resection with grafting, endovascular aortic repair) is recommended in the absence of significant comorbid conditions to reduce the likelihood of adverse complications [71,72,74,173].

(CRA C, LOR 4).

• In patients indicated for surgical treatment of a penetrating aortic ulcer located in the ascending aorta or the proximal arch (zones 0–1), open surgery is recommended over endovascular intervention to reduce early adverse events and improve long-term outcomes [173].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

• In patients indicated for surgical treatment of a penetrating aortic ulcer located in the distal arch (zones 2–3), descending thoracic aorta, or abdominal aorta, the consideration of both open and endovascular intervention is recommended, based on anatomical features and the patient's condition, to improve long-term outcomes [173].

(LoE C, GoR 4).

• In patients with isolated penetrating aortic ulcer who present with symptoms and persistent pain clinically correlating with radiological findings, surgical treatment is recommended to reduce the likelihood of adverse complications [9,73,158,173].

(LoE C, GoR 4).

• In asymptomatic patients with isolated penetrating aortic ulcer who have high-risk imaging features, elective surgical intervention is recommended to prevent the likelihood of adverse complications [9,158,159,173].

(LoE C, GoR 4).

• In patients with penetrating aortic ulcer requiring repair of the ascending aorta or proximal aortic arch, open surgical intervention is recommended to improve long-term outcomes [9,73,158,173].

(LoE C, GoR 4).

• In patients with penetrating aortic ulcer requiring repair in the distal aortic arch, descending thoracic aorta, or abdominal aorta, open or endovascular surgical intervention is recommended, with indications depending on aortic anatomy and comorbidities to reduce early adverse events and improve long-term outcomes [159-161,173].

(LoE B, GoR 3).

3.2.7 Traumatic aortic injury

• Treatment of patients with traumatic aortic injury is recommended to be carried out in a multidisciplinary hospital equipped with a specialized trauma and vascular department possessing the capabilities and experience in aortic surgical interventions to reduce early adverse events and improve long-term outcomes [115,120].

(CQR C, LVE 2).

Comments: The type of aortic injury is a critical factor in determining the timing of intervention. It should also be noted that in polytrauma patients, an interdisciplinary approach is of vital importance for correctly scheduling interventions and treatment priorities. Treatment of patients with traumatic aortic injury can be carried out in a multidisciplinary vascular center with a specialized trauma and vascular department equipped with the capabilities and experience in aortic surgical interventions.

• In patients with type 3 and 4 traumatic aortic injury without other life-threatening injuries and without comorbidity contraindications, aortic surgery is recommended to prevent adverse complications and mortality [121,122].

(LoE C, GoR 4).

Comments: To date, there is no consensus regarding the optimal timing of treatment for patients with traumatic aortic injury. It is believed that in hemodynamically stable patients, most aortic ruptures associated with traumatic aortic injury occur within 24 hours. For this reason, immediate treatment of traumatic aortic injury was considered the standard of care for many years. Subsequently, several studies demonstrated a reduction in mortality and paraplegia rates associated with delayed treatment in selected patients when specific procedures were required due to other extensive injuries. In such patients, aortic intervention should be performed as soon as possible after the initial trauma (i.e., within 24 hours). Patients with free aortic rupture or large periaortic hematomas should undergo emergency surgery. In all other cases, the intervention may be delayed for up to 24 hours to stabilize the patient and create optimal conditions for the procedure.

• In patients with type 2 traumatic aortic injury at high aortic risk (posterior mediastinal hematoma >10 mm, aortic-to-normal diameter ratio >1.4, extensive mediastinal hematoma, pseudoarctation of the aorta, massive left-sided hemothorax, involvement of the ascending aorta, arch or branches, aortic arch hematoma), aortic surgery (aortic resection with grafting and branch plasty, aortic resection with grafting, endovascular aortic repair) is recommended to prevent adverse complications and mortality [122-127].

(LoE C, GoR 4).

Comments: Open surgical reconstruction for traumatic aortic injury (aortic resection with grafting and branch plasty, aortic resection with grafting) at the classic site of the isthmus typically requires left posterolateral thoracotomy through the fourth intercostal space, as well as single-lung ventilation. The aorta is clamped proximal to the origin of the left subclavian artery and distal to the injured segment. Until the mid-1980s, the majority of these procedures were performed using the "clamp-and-go" technique. According to meta-analyses of this technique, mortality and paraplegia rates are 16–31% and 5–19%, respectively. Various methods of distal aortic perfusion are used for spinal cord protection. The use of cardiopulmonary bypass has been associated with a reduced risk of perioperative mortality and paraplegia. Meta-analyses and large cohort studies of active and passive perfusion have shown a lower incidence of postoperative paraplegia (19% vs. 3%) and mortality (30% vs. 12%) associated with active perfusion.

• In cases of traumatic aortic injury requiring surgical intervention, TEVAR (thoracic endovascular aortic repair) is recommended to be preferred over open surgery, provided anatomical conditions are suitable, to reduce early adverse events and improve long-term outcomes [128-130].

(Reliability of Evidence Level B, Consistency of Evidence Level 2).

Comments: Available data indicate that under suitable anatomical conditions, TEVAR should be preferred in the management of traumatic aortic injury. In a review of 139 studies (7,768 patients), most of which lack comparative analysis of patient series and are retrospective and non-randomized, TEVAR demonstrated lower mortality than open surgery (9% vs. 19%; p < 0.01). Similarly, most other systematic reviews suggest the benefits of TEVAR in terms of survival and reduced incidence of paraplegia compared to open repair. With TEVAR, the incidence of endoleaks was 5.2%, stent-graft compression (universal endovascular aortic stent-graft) – 2.5%, and long-term mortality – 12.9%.

• In patients with grade 2 traumatic aortic injury and concomitant malperfusion, the consideration of surgical treatment is recommended to relieve visceral ischemia [166].

(LoE C, GoR 4).

• In patients with traumatic aortic injury, routine resuscitative endovascular balloon occlusion of the aorta (transluminal balloon angioplasty of the aorta) for bleeding control is not recommended in order to reduce early adverse events and improve long-term outcomes [167].

(LEL C, EL 3).

Comments: efficacy is unclear and in some cases may cause harm.

3.2.8 Aortic dissection and pregnancy

• For female patients with type A acute aortic dissection during the period up to 27 weeks of gestation, it is recommended to resolve the issue of surgical intervention on the aorta within 2 days with fetal condition monitoring to reduce the risk of adverse events [140-142,173].

(LoE C, GoR 4).

• For female patients with type A acute aortic dissection from 28 weeks of gestation onwards, it is recommended to resolve the issue of delivery via cesarean section within 24 hours, followed by immediate surgical intervention on the aorta to prevent adverse complications and death [140-143,173].

(Level of Reliable Evidence C, Uncertainty of Evidence Level 5).

• For female patients with progressive aortic dilation up to 28 weeks of gestation, it is recommended to consider the feasibility of preemptive surgical intervention on the aorta, taking into account individual characteristics to avoid aortic complications [140,141,143,173].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

• For female patients from 28 weeks of gestation with a history of chronic aortic dissection, a cesarean section is recommended to reduce early adverse events and improve long-term outcomes [8,173].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

• For female patients who have experienced type B acute aortic dissection during pregnancy, medical therapy (see section 3.1.1) is recommended before and after delivery, unless endovascular or surgical reconstruction (aortic resection with branch reconstruction and plasty, aortic resection with replacement, aortic stent grafting) is required to treat acute complications in order to improve long-term outcomes [141,143,173].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

• In pregnant women with aortopathy and an aortic diameter < 4.0 cm, vaginal delivery is recommended to reduce early adverse events and improve long-term outcomes [140,143,173].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

• In pregnant women (from 28 weeks of gestation) with a diameter of the aortic root, ascending aorta, or both exceeding 4.5 cm, cesarean section is recommended to improve long-term outcomes [141,143,173].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

4. Medical Rehabilitation and Sanatorium-Resort Treatment

• For patients with type B acute aortic dissection after hospital discharge, careful indefinite follow-up by a surgeon every 3 months at their place of residence (preventive appointment (examination, consultation) by a surgeon) is recommended to monitor disease progression [4].

(CRA C, LOR 4).

Comments: to monitor disease progression, it is necessary to perform electrocardiography, echocardiography, abdominal ultrasound, targeted chest X-ray, and computed tomography angiography of the aorta once a year or upon signs of disease progression.

• For patients after open or endovascular surgical treatment (aortic resection with branch reconstruction and plasty, aortic resection with replacement, aortic stent grafting) of type A acute aortic dissection or intramural hematoma with persisting pathology of the residual aorta, dynamic monitoring at 1, 6, and 12 months with potential computed tomography angiography of the aorta, and then annually if stable, is recommended to monitor emerging complications [144-149].

(CRA C, LOR 4).

Comments: the same applies to patients who received conservative therapy alone [150]. In addition to computed tomography angiography of the aorta, transthoracic echocardiography may be useful for the dynamic monitoring of the aortic root and aortic valve.

• For patients after surgical or medical treatment of type A acute aortic dissection or intramural hematoma with persisting residual chronic pathology of the thoracic aorta and its aneurysmal dilation exceeding 5.5 cm, considering surgical intervention depending on the patient's comorbid status and risk factors is recommended to reduce adverse events and improve long-term outcomes [145,147,151,152].

(LoE C, GoR 4).

Comments: optimal postoperative management of patients after type A acute aortic dissection includes blood pressure control and lifelong follow-up using imaging modalities. Several important aspects of long-term monitoring should be taken into account. First, medical therapy aimed at normalizing blood pressure and reducing stress on the aortic wall must be prescribed and properly explained to patients to ensure adequate drug adherence. Second, imaging studies should be scheduled at appropriate time intervals. Diagnostic studies should focus on evaluating the aortic valve and left ventricular function, as well as aortic remodeling. Finally, first-degree relatives of patients should undergo echocardiography, and if clinical features are identified, the patient should be offered genetic testing to detect hereditary aortic diseases (cytogenetic testing (karyotype)).

• In patients with traumatic aortic disruption who have not undergone surgery, dynamic assessment of the aortic condition via computed tomography angiography of the aorta at 1, 6, and 12 months after the injury, and subsequently at appropriate intervals depending on the type and extent of the lesion if the aorta is stable, is recommended to monitor the appearance of post-traumatic complications [173].

(Reliability of Evidence Level C, Confidence Level in Recommendations 5).

Comments: currently, computed tomography angiography of the aorta is considered the standard imaging method after successful TEVAR. However, given the often young age of patients with traumatic aortic disruption, there are certain concerns regarding the cumulative exposure to ionizing radiation and iodine-containing radiopaque agents. For these reasons, the best alternative for long-term follow-up after the use of MRI-compatible stent grafts (universal endovascular aortic stent graft) is contrast-enhanced magnetic resonance angiography. It seems appropriate to use a combination of multi-projection targeted chest X-ray and contrast-enhanced magnetic resonance angiography rather than computed tomography angiography of the aorta, taking into account the metallic component of the stent graft (universal endovascular aortic stent graft), for the long-term monitoring of patients. Under these two conditions, endoleaks, pseudoaneurysms, and complications related to the stent graft material (universal endovascular aortic stent graft) can be detected.

Classification of endoleaks: Type I: leakage at the stent graft (universal endovascular aortic stent graft) attachment site above, below, or between graft components (Ia: proximal fixation zone; Ib: distal fixation zone). Type II: the aneurysmal sac fills retrogradely via one (IIa) or multiple side branches (IIb). Type III: leakage through a mechanical defect in the graft, mechanical damage to the stent graft (universal endovascular aortic stent graft) resulting from the separation of modular components (IIIa), or fractures and holes in the endoprosthesis (IIIb). Type IV: leakage through the graft fabric due to its porosity. Type V: continued expansion of the aneurysmal sac without obvious leakage on imaging (endotension).

5. Prevention and Dispensary Observation

• For patients after medical treatment of penetrating atherosclerotic ulcer, dynamic monitoring with computed tomography angiography of the aorta at 1 month, then every 6 months for 2 years if stable, and subsequently at appropriate intervals depending on age and penetrating atherosclerotic ulcer characteristics is recommended to monitor disease progression [153,156].

(LoE C, GoR 4).

Comments: mortality rates with medical treatment are high in Europe and the USA, unlike in Asia. According to IRAD, in-hospital mortality for type A intramural hematoma is similar to that of type A aortic dissection and is caused by the proximity of the lesion to the aortic valve. On the other hand, several studies have shown that 30–40% of type A intramural hematomas transform into aortic dissection, with the highest risk in the first 8 days after symptom onset. In acute type B intramural hematoma, the risk of in-hospital mortality is < 10%, similar to type B aortic dissection. The long-term prognosis in patients with intramural hematoma is more favorable compared to patients with aortic dissection. However, the 5-year survival rate for intramural hematoma ranges from 43–90% depending on patient characteristics. Local destruction (ulcer-like projection – ULP) of the aorta may appear within the first days or months after symptom onset, which distinguishes it from penetrating atherosclerotic ulcer, which is associated with atherosclerosis of the aortic wall. Although ULP of the ascending aorta has an unfavorable prognosis, the course of the disease is more benign in type B intramural hematoma.

• For patients after surgical treatment of penetrating atherosclerotic ulcer, dynamic monitoring with computed tomography angiography of the aorta at intervals corresponding to interventions for type A acute aortic dissection is recommended to monitor disease progression [153-155].

(Reliability of Evidence Level C, Confidence Level in Evidence 3).

6. Organization of Medical Care

Indications for planned hospitalization:

1) presence of symptoms of brain, internal organ, kidney, lower limb malperfusion, aortic regurgitation, aortic aneurysm;

2) elective surgical treatment.

Indications for emergency hospitalization:

1) acute aortic dissection;

2) complicated course of chronic dissection.

Indications for patient discharge from the hospital:

1) stabilization of the patient's condition in the subacute and chronic phases of aortic dissection;

1) absence of indications for emergency surgical intervention.

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

Guideline Expert Panel:

Working Group Supervisor: Arakelyan V.S., MD, PhD (Moscow).

Responsible Investigators: Mironenko V.A., MD, PhD (Moscow),

Papitashvili V.G., PhD (Moscow).

Executive Secretary: Kokoev M.B., PhD, Khon V.L., PhD (Moscow).

Expert Panel Members:

S.A. Abugov (Moscow),

T.B. Averina (Moscow),

B.A. Akselrod (Moscow),

R.S. Akchurin (Moscow),

B.G. Alekyan (Moscow),

V.S. Arakelyan (Moscow),

Yu.V. Belov (Moscow),

A.N. Vachev (Samara),

M.L. Gordeev (Saint Petersburg),

R.K. Dzhordzhikiya (Kazan),

A.A. Dyuzhikov (Rostov-on-Don),

I.A. Eroshkin (Moscow),

T.E. Imaev (Moscow),

Z.A. Kavteladze (Moscow),

A.M. Karaskov (Moscow),

S.A. Kovalev (Voronezh),

L.S. Lokshin (Moscow),

V.A. Mironenko (Moscow),

K.V. Petrosyan (Moscow),

E.V. Roseykin (Penza),

M.M. Rybka (Moscow),

V.V. Sokolov (Moscow),

A.V. Troitskiy (Moscow),

A.A. Fokin (Chelyabinsk),

I.E. Chazova (Moscow),

E.R. Charchyan (Moscow),

I.I. Chernov (Astrakhan),

A.M. Chernyavsky (Novosibirsk),

A.V. Chupin (Moscow),

K.V. Shatalov (Moscow),

V.N. Shipovsky (Moscow),

E.V. Shlyakhto (Saint Petersburg),

Yu.A. Shneider (Kaliningrad).

All members of the Working Group have confirmed that they have no financial support or conflicts of interest to disclose.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience of the developed clinical guidelines:

1. Cardiovascular Surgeon

2. Thoracic surgeon

3. Surgeon

4. Ultrasound Diagnostics Physician

5. Radiologist

Methods for evidence collection/selection: search in electronic databases

Description of methods used to assess the quality and strength of evidence: the evidence base for the recommendations consists of publications included in the PubMed, Scopus, and Google Scholar databases. The search depth was 30 years.

Table P1. Scale for assessing levels of evidence certainty (LEC) for preventive, therapeutic, and medical rehabilitation methods, including those based on natural healing factors (preventive, therapeutic, and rehabilitation interventions)

Table P2. Scale for assessing levels of evidence certainty (LEC) for diagnostic methods (diagnostic interventions)

Table P3. Scale for assessing recommendation consensus strength (RCS) for preventive, diagnostic, therapeutic, and medical rehabilitation methods, including those based on natural healing factors (preventive, diagnostic, therapeutic, and rehabilitation interventions)

Related Documents

1. Federal Law No. 323-FZ dated November 21, 2011, "On the Fundamentals of Protecting the Health of Citizens in the Russian Federation".

2. Procedure for providing medical care to patients with cardiovascular diseases (Order of the Russian Ministry of Health No. 918n dated November 15, 2012).

3. Order of the Ministry of Labor of Russia No. 374n dated July 26, 2024, "On Approval of Classifications and Criteria Used in Carrying out Medical and Social Expertise of Citizens by Federal Medical and Social Expertise Institutions" (Registered with the Ministry of Justice of Russia on August 23, 2024, No. 79273).

Procedure for updating clinical guidelines

Clinical guidelines are updated every 3 years.

Appendix A3. Reference Materials

PAU dimensions

A – maximum aortic diameter in the ulcer region (from the ulcer floor to the opposite wall), B – ulcer depth, C – extent of the intimal defect in the ulcer region, D – maximum width of the ulcer within the aortic wall (adapted from [157])

PAU classification

The goals of initial medical therapy in patients with normal or elevated blood pressure should focus on reducing wall stress on the aorta, suppressing false lumen propagation, and ultimately preventing rupture. Forces acutely influencing the dissection process include heart rate, blood pressure, and ventricular contractility rate. These parameters can be stabilized by early blockade to target systolic blood pressure values of 100 to 120 mm Hg and a heart rate below 60 beats per minute. By reducing afterload and myocardial oxygen consumption rate, anti-impulse therapy (antihypertensive agents) also provides improved myocardial perfusion. Typical agents include intravenous propranolol, esmolol, or metoprolol**.

Esmolol has a uniquely short half-life, and a beta-blocker with inherent intrinsic sympathomimetic activity provides a powerful advantage in achieving heart rate and blood pressure control, potentially reducing the need for additional drugs. Some contraindications to beta-blockers include asthma, chronic obstructive pulmonary disease, or atrioventricular block. Potential alternatives in patients with contraindications or those unable to tolerate beta-blockers are non-dihydropyridine calcium channel blockers (phenylalkylamine and benzothiazepine derivatives) – verapamil** or diltiazem. Both drugs should be used with caution in the setting of severe AR, as they may induce reflex tachycardia.

Additional drugs may be required if hypertension is refractory to a single agent. Peripheral vasodilators should be used with caution after prior chronotropic control is established with beta-blockers to avoid reflex tachycardia. Intravenous sodium nitroprusside dihydrate has also been used effectively in the setting of acute AD, but the toxicity of its primary metabolites (cyanide and thiocyanate) with prolonged infusion is a significant side effect.

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers are also reasonable options, but they are more difficult to titrate.

Intravenous opioids should be initiated as early as possible after diagnosis and rapidly titrated for pain relief.

Appendix B. Physician Action Algorithms

Management algorithms for patients with type A acute aortic dissection

Appendix C. Patient Information

What is aortic dissection and how does it occur?

Aortic dissection is the destruction of the middle layer of the aortic wall caused by intramural blood entry, followed by the separation/dissection of the wall layers and the formation of two lumens with or without communication between them.

Aortic dissection may also extend to visceral branches. Other complications include cardiac tamponade, aortic valve regurgitation, and organ malperfusion syndrome.

Such changes are most commonly found in smokers, patients with diabetes mellitus, hypertension, and elevated blood lipid levels.

The etiology of aortic dissection is believed to be associated with underlying weakness in the aortic tunica media, exacerbated by an intimal tear, vaso vasorum rupture (intramural hematoma), or rupture of an atherosclerotic plaque/ulcer.

Other causes may include congenital connective tissue dysplasia ("weakness") of the vessel wall.

What can happen without treatment?

The natural course of this disease is associated with a high risk of formidable complications:

Progression of visceral circulatory impairment with the development of multiple organ failure, up to death

Development of an aortic aneurysm, the walls of which are very thin and can rupture suddenly, resulting in acute, almost always fatal hemorrhage;

Surgical treatment helps avoid these dangers.

How is the surgery performed?

Surgery is performed under general anesthesia. The risks of anesthesia will be explained to you in detail by the anesthesiologist. The goal of the surgery is to eliminate symptoms of circulatory impairment in visceral organs (brain, upper and lower extremities, kidneys, gastrointestinal tract, heart) and prevent the development of complications (aneurysm formation, dissection progression, aortic wall rupture, etc.). For this purpose, an incision (along the midline of the abdomen, a lateral abdominal incision, sternotomy) is made to expose the aorta, the aorta is clamped, and a synthetic graft is sutured in to eliminate the consequences of aortic dissection. Aortic and arterial grafts are not rejected and serve faithfully throughout the patient's life. In minimally invasive procedures, a special graft (stent graft) is placed into the aortic lumen through a groin incision.

Temporary drainage tubes are left in the wound to evacuate wound secretions. Following the completion of surgery, a contrast X-ray examination is sometimes performed.

An increase in the scope of surgery may be necessary.

The physician discusses the stages of the surgical intervention with you; however, during the surgery, the need for additional unplanned steps may arise. Your consent must also be obtained for this; otherwise, the surgery will be stopped. Reoperation will be performed after additional discussion with you, which will increase treatment duration and the likelihood of dangerous complications and an adverse outcome.

What complications can occur?

In certain cases, complex surgeries may be associated with complications.

General complications:

Postoperative bleeding, large hematomas;

Infectious complications. Wound suppuration occurs, requiring further therapeutic measures. In this case, wounds heal slowly, with the formation of keloid scars;

Formation of blood clots in veins with potential pulmonary embolism. If your risk is elevated, you will receive prophylactic medications that lower blood clotting. These drugs may increase the tendency for bleeding. When administering these drugs, as with any other injection, abscesses may occur in rare cases;

Compression of nerves and soft tissues due to the prolonged immobile body position required during surgery. These complications are very rare and typically resolve within a week. In isolated cases, complaints (e.g., a feeling of numbness) and scars may persist. Skin damage from disinfectants may also occur;

Blood or blood component transfusion, which may be required under certain circumstances. Transmission of infections (e.g., hepatitis viruses, HIV/AIDS) is extremely rare;

Hypersensitivity reactions (allergies) to medications, anesthetics, and contrast agents, which may manifest as itching, for example. Extremely severe reactions such as collapse, seizures, and respiratory failure are very rare, require inpatient treatment, and may lead to irreversible consequences;

Excessive scarring. Given appropriate predisposition, thick, bumpy, and/or painful scars (keloids) may develop, similar to any other surgery;

Specific complications:

Damage to adjacent organs such as the intestine, ureter, bladder, etc., which will require a corresponding expansion of the surgical procedure;

Spinal cord ischemia, temporary or permanent, may rarely occur due to impaired spinal cord blood supply during aortic clamping;

Renal failure. Clamping the aorta above the origin of the renal arteries restricts blood supply to the kidneys, resulting in renal failure. Blood purification methods (dialysis) may become necessary;

Impaired blood supply to the intestine and liver due to aortic clamping during surgery. Resection of a segment of the bowel may occasionally be required. In emergency situations, the creation of an artificial anus (bringing the bowel to the anterior abdominal wall) may be necessary;

Occlusion (thrombosis) or embolism of the prosthesis and the vascular segments above and below it. The consequence is reduced organ blood supply and disease recurrence. In this case, the need for surgical or conservative treatment will be discussed.

Infection of the prosthesis, which may lead to hemorrhage from the suture lines; if the infection progresses, removal of the prosthesis may be required, resulting in a significant impairment of organ blood supply.

Postoperative expansion of the aorta at the site of prosthesis attachment; significant expansion must be addressed via reoperation.

All of the aforementioned complications may occur following surgery. However, serious complications are rare: in reoperations (if recurrence occurs), in progressive disease, in obesity, or in the presence of concomitant diseases and smoking.

What is the outlook?

In most cases, surgery leads to an improvement in condition and the disappearance of symptoms.

Maintaining the positive outcome of the surgery requires your active participation. Treatment and prevention of the progression of the underlying disease are necessary. To this end, you must completely stop smoking, discuss a special diet and the elimination of risk factors with your attending physician.

What should you pay attention to?

Postoperative follow-up examinations are particularly important for the timely assessment of the condition of the operated vessel and the detection of potential complications.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Not applicable.