List of Abbreviations
ICD-10 – International Classification of Diseases, 10th Revision
HN – hydronephrosis
HNT – hydronephrotic transformation
AHN – antenatal hydronephrosis
UUT – upper urinary tract
UTI – urinary tract infection
UPJ – ureteropelvic junction
PUJ – pyeloureteral junction
Pelvicalyceal system – pelvicalyceal system
upper third – upper third
US – ultrasound examination
RI – resistive index on duplex Doppler ultrasonography
APPD – anteroposterior diameter (of the renal pelvis)
fUS – functional ultrasound (syn. diuretic ultrasound)
DRP – diagnostic radiopharmaceutical
DRF – differential (split) renal function
T 1/2 – half-life of radiopharmaceutical excretion from the pelvicalyceal system against the background of a diuretic
TTP – parenchymal transit time of the radiopharmaceutical
CT – computed tomography
SCT – spiral computed tomography
MRI – magnetic resonance imaging
VCUG – voiding cystourethrography
RNC – static renal scintigraphy
mm – millimeter
mmHg – millimeter of mercury
ESR – erythrocyte sedimentation rate
CRF — chronic renal failure
LP – laparoscopic pyeloplasty
PCN – percutaneous nephrostomy
SFU – Society of Fetal Urology
EAU – European Association of Urology
ESPU – European Society for Paediatric Urology
Terms and Definitions
Hydronephrosis (Greek *hydōr* – water, *nephros* – kidney; syn. hydronephrotic transformation) is dilation of the renal pelvicalyceal system.
Diaperapeutics – simultaneous transition from a diagnostic stage to an effective instrumental therapeutic intervention.
Pelvicalyceal-ureteral junction (from Greek *pyelos* – trough, pelvis and *ureter* – ureter) is the initial segment of the proximal part of the ureter about 1 cm long, which is the transition site from the renal pelvis to the ureter.
Pelvicalyceal-ureteral junction obstruction (Latin *obstructio* – obstacle, hindrance) is impaired patency of the peri-pelvic section of the ureter due to internal narrowing (stenosis) or external compression of its lumen.
Pelvicalyceal-ureteral junction plasty is a reconstructive plastic surgery to restore ureteral patency in the area of transition from the pelvis to the ureter.
Pelvicalyceal-ureteral junction stenosis – persistent narrowing of the pelvicalyceal-ureteral junction lumen.
Endopyelotomy is an endoscopic method for restoring PUJ patency by internal dissection of the tissues narrowing its lumen.
1. Brief information on the disease or condition
1.1 Definition of the disease or condition
Hydronephrosis (pelvicalyceal-ureteral junction stenosis) is a persistent and progressively increasing dilation of the pelvicalyceal system accompanied by impaired urine outflow from the kidney into the proximal parts of the ureter. This pathological condition leads to increased intrapelvic pressure and atrophy of the renal parenchyma [1].
1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)
Depending on the time of onset, hydronephrosis can be congenital or acquired.
Primary (congenital) hydronephrosis develops due to abnormalities of the upper urinary tract in the pelvoureteral junction (PUJ) area.
Secondary (acquired) hydronephrosis is a consequence of cicatricial changes in the pelvicalyceal-ureteral junction (PCUJ) of unclear origin or the result of complications of various diseases leading to impaired urine outflow from the kidney.
Congenital and acquired hydronephrosis can be the result of various internal and external causes leading to narrowing (stenosis) of the ureteral lumen in the peri-pelvic section.
Etiology of congenital PUJ stenosis/obstruction and primary hydronephrosis:
Internal cause – narrowing (stenosis) of the ureteral lumen in the peri-pelvic section due to structural changes in the ureteral wall.
Internal causes of PUJ obstruction/stenosis:
1. Ureteral stenosis at the PUJ due to abnormal development of smooth muscle structures and innervation disorders [2], which determines the presence of an adynamic, aperistaltic ureteral segment that prevents the development of an effective peristaltic wave (the most common cause of hydronephrosis, 75%) [3];
2. Congenital urothelial valves of the ureter in the PUJ area.
External causes – narrowing of the internal lumen of the PUJ due to external compression.
External causes of PUJ obstruction/stenosis:
1. Vasoureteral conflict. An accessory lower-segmental (aberrant) vessel causing compression of the PUJ and/or the upper third (u/3) of the ureter and impairing urine outflow from the pelvicalyceal system. An aberrant vessel can occur in 40% of cases. At the same time, the mere fact of its presence in the PUJ area does not mean that the vessel is the direct cause of the obstruction. In some cases, the crossing of the ureter by the vessel causes only a mechanical obstacle. However, over time, crossing vessels lead to inflammation of the PUJ, fibrosis, and smooth myocyte hypertrophy, subsequently leading to obstruction. In the presence of vasoureteral conflict, it is customary to speak of a combined cause of impaired urine outflow from the pelvicalyceal system (PCS): an accessory vessel and a scarred PUJ. Crossing by an aberrant vessel is more commonly observed along the anterior surface [4].
2. Ureteral kinks fixed by embryonic adhesions;
3. Abnormal location (dystopia) of the PUJ – high origin of the ureter from the pelvis.
Etiology of acquired PUJ stenosis and secondary hydronephrosis:
1. Scarring of the PUJ of unknown origin;
2. Fibroepithelial polyps (a rare cause of PUJ stenosis) [5];
3. Malignant neoplasms of the ureter;
4. Scar-adhesive process in the PUJ area after trauma or surgery on the upper urinary tract (UUT);
5. Post-inflammatory periureteritis with PUJ scarring in nephrolithiasis (long-term presence of a calculus in the PUJ).
Congenital anomalies of the UUT associated with hydronephrosis:
· Horseshoe kidney;
· Renal duplication;
· Lumbar renal dystopia [6].
Also, long-term studies of the causes of antenatally detected hydronephrosis indicate that in most cases this pathology has a functional or transitory nature (41–88%), is a consequence of maturation dysfunction of the pelvis and/or ureter, and resolves spontaneously in the early postnatal period [7]. This category of patients may subsequently have no clinical symptoms and require no surgical treatment.
1.3 Epidemiology of the Disease or Condition
Urogenital malformations account for 30% of all intrauterine-detected anomalies. Among them, hydronephrosis is one of the most frequently detected pathologies, observed in approximately 1–5% of all pregnancies, due to various reasons [8]. A family, hereditary history of hydronephrosis is also a risk factor for the development of this disease [9].
PUJ stenosis/obstruction ranks second in frequency after transitory hydronephrosis among the causes of antenatally detected hydronephrosis (50%). The incidence of hydronephrosis in newborns is 1:1500. It is twice as common in boys as in girls, and is usually (in 2/3 of cases) detected on the left side. Bilateral obstruction is noted in approximately 30% (range 10–46%) of cases [10, 11]. Hydronephrosis occurs in 1% of patients aged 20–40 years, and is 1.5 times more common in women than in men [12]. In patients older than 40 years, hydronephrosis often serves as a manifestation of other diseases.
1.4 Features of Coding the Disease or Condition
N13.0 – Hydronephrosis with pelvicalyceal junction obstruction
N13.1 – Hydronephrosis with ureteral stricture, not elsewhere classified
Q62.0 – Congenital hydronephrosis
1.5 Classification of the disease or condition
To assess the severity of hydronephrotic transformation (HNT) in Russia, the classification proposed by Academician N.A. Lopatkin (1969) is most widespread, according to which three stages of hydronephrosis are distinguished, while the third is subdivided into two substages, 3A and 3B [13]:
Stage 1 – initial hydronephrosis, characterized by pyelectasis without the development of significant hydrocalyx and impaired renal function;
Stage 2 – early hydronephrosis, in which dilation of the pelvicalyceal system is accompanied by deterioration of renal function;
Stage 3 (A and B) – terminal hydronephrosis, characterized by significant dilation of the pelvicalyceal system and a substantial decrease in renal function. Stage 3A hydronephrosis is potentially reversible; in stage 3B hydronephrosis, the renal parenchyma is atrophied, and changes are irreversible.
In global practice among adult and pediatric urologists, the ultrasound classification of hydronephrosis by Onen A. (2007) [14] is popular – a modification of the Society for Fetal Urology (SFU, 1993) scoring system [15]. Compared to the SFU classification, the Onen system includes not only the assessment of pelvicalyceal system dilation, but also the state of the renal parenchyma.
There are 4 degrees of hydronephrosis:
Grade I – dilation of the renal pelvis without caliceal dilation (pyelectasis);
Grade II – dilation of the renal pelvis and major calices (pyelocalicectasis);
Grade III – dilation of the pelvis, major, and minor calices, thinning of the parenchyma up to 50% relative to normal;
Grade IV – dilation of the pelvis and calices with parenchymal thinning of more than 50% relative to normal.
Both classifications are acceptable and generally consistent: stage 3B according to N.A. Lopatkin implies irreversible changes in the renal parenchyma and, consequently, loss of the kidney, while grade IV according to A. Onen also implies the presence of marked organ changes bordering on end-stage disease.
In pediatric urology, two ultrasound classification systems are mainly used to diagnose and assess the severity of prenatal and postnatal hydronephrosis: the Antero-posterior Diameter of Renal Pelvis (APDRP) by A. Grignon et al. [16] and the alternative Society for Fetal Urology (SFU) grading system by A. Onen, presented above [14].
The Antero-posterior Diameter of Renal Pelvis (APDRP) classification system is a quantitative assessment of the degree of pelvic dilation based on measuring its maximum anteroposterior diameter (APD) on sonographic images of the kidney obtained in the transverse plane at the level of the renal hilum [16].
It classifies antenatal hydronephrosis (AHN) into mild, moderate, and severe degrees based on renal pelvis APD threshold values at various gestation periods:
· Mild degree: APD from 4 to 7 mm in the 2nd trimester, 7–9 mm in the 3rd trimester;
· Moderate degree: APD from 7 to 9 mm in the 2nd trimester, 9–15 mm in the 3rd trimester;
· Severe degree: APD >10 mm in the 2nd trimester, >15 mm in the 3rd trimester.
A high risk of clinically significant hydronephrosis is defined by renal pelvis APD values of ≥ 10 mm before 28 weeks of gestation and >15 mm after 28 weeks [17, 18].
In the postnatal period, mild, moderate, and severe hydronephrosis are distinguished based on the assessment of renal pelvis APD and the SFU classification:
· Mild degree: APD <20 mm or SFU grade I–II;
· Moderate degree: APD in the range of 20–30 mm or SFU grade III;
· Severe degree: APD >30 mm or SFU grade IV.
1.6 Clinical presentation of the disease or condition
There are no specific clinical symptoms characteristic of hydronephrosis. Before the introduction of antenatal ultrasound screening, a palpable abdominal mass was the most common symptom in newborns and infants, with urinary tract infection (UTI) being the second most frequent clinical symptom.
Currently, thanks to the widespread use of screening ultrasound examinations in pregnant women, hydronephrosis is diagnosed antenatally, which allows for the identification of a population of children with this pathology before the development of complications (renal dysfunction, recurrent urinary tract infections, urolithiasis, and arterial hypertension).
Many cases of hydronephrosis are asymptomatic for a long time or are discovered incidentally during ultrasound examinations performed for other reasons. The severity of clinical manifestations of hydronephrosis mainly depends on the stage of the disease, the cause of ureteropelvic junction (UPJ) obstruction, and complications.
In adults and older children, symptoms may include intermittent abdominal or flank pain, nausea, vomiting, hematuria, or signs of urinary tract infection. Laboratory tests may reveal microhematuria or pyuria [9, 19]. Arterial hypertension is rare. In cases of complete UPJ obstruction, the clinical picture of a "blocked kidney" manifests. Bilateral hydronephrosis presents with complaints caused by progressive impairment of renal function and azotemia.
2. Diagnostics, medical indications and contraindications for diagnostic methods
Diagnostic criteria:
1. Intermittent pain in the abdomen or flank on the affected side, nausea, vomiting, hematuria, or signs of urinary tract infection
2. Dilation of the pelvicalyceal system due to narrowing of the UPJ according to imaging diagnostics
When hydronephrosis is suspected , differential diagnosis is carried out with various kidney and abdominal cavity diseases depending on the predominant manifestations in the clinical picture [58]:
In the presence of pain, differential diagnosis is performed with nephrolithiasis and nephroptosis. Plain radiography or MSCT allows confirmation or exclusion of nephrolithiasis. Unlike hydronephrosis, in nephroptosis, pain occurs with movement and physical exertion and quickly subsides at rest. Comparing excretory urograms in the supine and upright positions allows the diagnosis of nephroptosis. UPJ stricture and nephroptosis can coexist.
In the case of a palpable retroperitoneal mass, hydronephrosis should be differentiated from a tumor, polycystic kidney disease, and a simple renal cyst.
In the case of a tumor, the kidney is fixed, dense in consistency, with a nodular surface. Pyelography reveals characteristic deformation of the renal pelvis with compression or "amputation" of the calyces.
In polycystic kidney disease, both kidneys are enlarged and nodular. Signs of renal failure are detected. Pyelography reveals an elongated renal pelvis and branching calyces stretched into crescent shapes.
In a simple renal cyst, pyelography reveals compression of the pelvicalyceal system corresponding to the location of the cyst. The diagnosis is established after ultrasound and MSCT.
In the presence of hematuria and pyuria, hydronephrosis should be differentiated from renal pelvis tumors, pyonephrosis, and renal tuberculosis (mainly using radiological methods).
When pelvicaliectasis is detected, hydronephrosis should be differentiated from the following conditions and diseases (radioisotope testing in most of these conditions reveals no impaired renal function):
— diabetes insipidus;
— diuretic intake;
— physiological polydipsia and polyuria;
— calyceal diverticula;
— polymegacaliciosis;
— extrarenal pelvis;
— Prune-Belly syndrome;
— parapelvic cyst;
— papillary necrosis;
— physiological dilation of the upper urinary tract during pregnancy.
When ureteropyelocaliectasis is detected, ureterohydronephrosis should be differentiated from:
— vesicoureteral reflux (diagnosed via voiding cystourethrography);
— ureterocele;
— megaureter;
— ureteral positioning anomalies (retrocaval, retroiliac ureter).
Excretory urography and MSCT help establish the diagnosis.
2.1 Complaints and Anamnesis
Relevant complaints and medical history are listed in the Clinical Presentation section (Appendix B).
2.2 Physical Examination
To diagnose hydronephrosis, it is recommended that all patients undergo a physical examination [20].
Level of Evidence CLevel of confidence in recommendations C (level of reliability of evidence – 5)
Comments: inspection, palpation, percussion, and auscultation have low or no diagnostic value in the initial and early stages of hydronephrosis. Symptoms of great diagnostic importance for hydronephrosis only appear as the disease progresses, upper urinary tract changes worsen, and the functional state of the renal parenchyma deteriorates.
Palpation of the kidneys and abdomen is an unreliable method for diagnosing hydronephrosis. As long as the structural and functional state of the upper urinary tract is compensated, palpation provides no significant information. Only in end-stage A and B hydronephrosis, often accompanied by giant dilation of the pelvicalyceal system, can a ballotable mass be determined via bimanual palpation. Percussion of the abdomen over the altered kidney usually fails to reveal any changes.
Auscultation of the abdomen in patients with UPJ stenosis and hydronephrosis also lacks characteristic signs. Thus, objective examination methods during physical inspection are not decisive in diagnosing UPJ stenosis and hydronephrosis, especially in the early stages of their development.
2.3 Laboratory Diagnostics
All patients with suspected hydronephrosis are recommended to undergo a complete (clinical) blood count to rule out an acute inflammatory process [21].
Level of Evidence CLevel of confidence in recommendations C (level of reliability of evidence – 5)
Comments: The clinical blood count in hydronephrosis may fall within age-related norms, but the presence of leukocytosis (elevated blood leukocyte levels) may indicate an acute inflammatory or infectious process.
All patients with suspected hydronephrosis are recommended to undergo a general biochemical blood test (creatinine, urea, albumin, potassium, sodium, chlorides) to assess renal function [21].
Level of Evidence CLevel of confidence in recommendations C (level of reliability of evidence – 5)
Comments: In the biochemical blood test, renal function is assessed by the following parameters: creatinine, urea, albumin, and electrolytes (potassium, sodium, chlorides). In bilateral hydronephrosis, the following may be diagnosed: elevated blood creatinine and urea levels, and changes in blood electrolytes (elevated or decreased potassium, sodium, chlorides), indicating impaired renal function (renal failure). Furthermore, hyperkalemia resulting from hydronephrosis is a life-threatening condition.
All patients with suspected hydronephrosis are recommended to undergo a general (clinical) urinalysis to rule out urogenital tract infection [21].
Level of Evidence CLevel of confidence in recommendations C (level of reliability of evidence – 5)
Comments: The clinical urinalysis in hydronephrosis is usually within normal limits, but the presence of white blood cells (leukocyturia) and red blood cells (hematuria) may indicate urolithiasis or a tumor, which are frequently the causes of obstruction and subsequent hydronephrosis, or occur when urinary tract obstruction becomes complicated by infection. Pyuria (presence of pus) indicates urogenital infection. Microscopic hematuria points to the presence of a stone or tumor in the urinary system.
In patients with a nephrostomy tube, it is recommended to assess nephron function via creatinine clearance (Rehberg's test) to clarify the nature of renal parenchymal changes and evaluate renal filtration function [20].
Level of Evidence CLevel of confidence in recommendations C (level of reliability of evidence – 5)
Comments: to evaluate the functional state of the kidneys in patients with a nephrostomy, the excretory function of the renal parenchyma (glomerular filtration) is assessed separately using endogenous creatinine clearance adjusted for urine output. The ability of the kidneys to acidify urine is determined; this ability is reduced in pronounced degenerative changes of the tubular epithelium (characteristic of patients with late, irreversible stages of HN).
2.4 Instrumental Diagnostics
It is recommended to perform a renal ultrasound (ultrasound examination) in all patients with suspected hydronephrosis to confirm and determine the grade of hydronephrosis, and to assess the condition of the parenchyma in the affected and contralateral kidneys [19].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: Ultrasound ranks first among diagnostic procedures used to detect UPJ obstruction and HN. However, this technique does not provide information on the cumulative and excretory function of the kidneys. Since pelvicalyceal system (PCS) dilatation is not always the result of UPJ obstruction, ultrasound may yield false-positive results. Ultrasound can be recommended as a method for the dynamic follow-up of patients who have undergone reconstructive-plastic or endoscopic surgeries by measuring the anteroposterior diameter (APD) of the renal pelvis before and after the surgical procedure [22, 23].
It is recommended to perform a renal ultrasound with a functional (pharmacological (diuretic)) load (fUS or dUS) in adult patients with suspected hydronephrosis to assess evacuation function, PCS contractility, the degree of UPJ obstruction, and urodynamic disorders [19, 20].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: renal ultrasound with assessment of PCS dimensions before and after administration of a drug from the sulfonamide group (ATX code C03CA) has historically been a classic method for confirming the relationship between pain, UPJ obstruction, and impaired urine outflow from the kidney, visualizing the upper urinary tract (UUT), and assessing the compensatory reserves of the pelvicalyceal system. The role of fUS (dUS) in confirming UPJ obstruction can be of significant clinical importance, especially in hospitals lacking advanced upper urinary tract imaging methods. It has limitations in patients with a significantly reduced volume of functioning renal parenchyma, newborns, and cases of marked PCS dilatation.
In pediatric patients, the indications for dUS are the same as in adults, as well as for differentiating between obstructive hydronephrosis and non-obstructive PCS dilatation.
It is recommended to perform duplex scanning of the renal arteries in all patients with HN to assess renal blood supply and detect accessory vessels when other imaging modalities are insufficiently informative [29].
Level of Evidence AGrade of Recommendation 2 Level of Evidence A (grade of recommendation – 2)
Comments: impaired urine outflow from the PCS leads to an alteration in the Doppler waveform determined using the resistivity index (RI). An RI value greater than 0.7 indicates obstruction. In adult patients, this diagnostic test has a sensitivity of 92% and a specificity of 88%.
It is recommended to perform intravenous urography in all patients aged 1 month and older with suspected hydronephrosis to assess the structural and functional state of the upper urinary tract, as well as the dimensions of the pelvicalyceal system and the degree of urinary outflow impairment based on the evacuation time of the diagnostic radiopharmaceutical from the collecting system of the hydronephrotically altered kidney [19].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: a traditional method for diagnosing UPJ obstruction and HN. It may be a justified first-line imaging method in centers not equipped with spiral computed tomography (SCT) scanners. However, the use of this technique is contraindicated in children under two weeks of age, and limited in infants during the first months of life due to the immaturity of the renal parenchyma and a high risk of complications (ranging from allergic reactions and the development of contrast-induced nephropathy to renal vein thrombosis and medullary necrosis [30]. Intravenous urography is contraindicated in patients with a history of intolerance to iodinated radiocontrast agents (ATX code V08A).
Performing intravenous urography is contraindicated in children under two weeks of age, and has limitations in infants during the first months of life due to potential toxic effects of contrast agents (up to the development of contrast-induced nephropathy, acute renal failure) and high radiation exposure.
It is recommended to perform intravenous (infusion) urography in newborns and infants with reduced renal concentrating function to improve visualization of the urinary tract, as well as due to the morphological "immaturity" of the nephron, which reduces the clarity of renal opacification [31].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
If loading diuretic tests are necessary during instrumental examinations, it is recommended to use a drug from the sulfonamide group (ATX code C03CA) in the following regimens:
— 1 mg/kg for patients in their first year of life and 0.5 mg/kg for patients aged one to sixteen years, up to a maximum dose of 20 mg in children [39, 43, 45];
— 0.5 mg/kg for patients aged 18 years and older, with a maximum dose of 40 mg [39].
Level of Evidence CReliability of Evidence 5Level of Confidence C (Level of Evidence – 5)
It is recommended to perform voiding cystourethrography or micturitional cystourethrography (MCUG) in patients under 1 year of age with suspected HN and echo-signs of high-grade hydronephrosis (SFU III–IV with a pelvic APD ≥ 15 mm), distal ureteral dilation (unilateral or bilateral), as well as in cases of severe voiding dysfunction (residual urine) and a history of febrile urinary tract infection to rule out vesicoureteral reflux and differentiate UPJ obstruction and HN from ureterohydronephrosis resulting from lower urinary tract dysfunction [24].
Level of Evidence CReliability of Evidence 5Level of Confidence C (Level of Evidence – 5)
Comments: MCUG is not used as a screening tool for vesicoureteral reflux (VUR) in newborns and infants with UPJ obstruction and HN due to the invasive nature of this examination, radiation exposure, high risk of urinary tract infection [25], and high radiation dose [26].
In pediatric patients with moderate-to-severe hydronephrosis (SFU III–IV), ureterocystography helps differentiate an obstructive cause of HN from a cause due to VUR, which is diagnosed on the ipsilateral side in approximately 20% of these patients [27].
Patients with low-grade HN (SFU I–II), normal renal parenchyma, and symmetrical kidney size do not require MCUG [28].
The volume of a water-soluble nephrotropic low-osmolar radiocontrast agent (iohexol** or iodixanol) administered via a sterile catheter placed in the urinary bladder corresponds to the age-specific bladder capacity, calculated in children under two years of age using the formula: V (mL) = Weight (kg) × 7, and in children over two years of age using Koff's formula: V (mL) = 30 × (age in years + 1). In older children and adult patients, it corresponds to the mean effective bladder capacity calculated from spontaneous voiding diary data.
It is recommended to perform computed tomography of the kidneys and upper urinary tract with intravenous bolus contrast enhancement in patients older than 3 months with suspected hydronephrosis to assess the structural and functional state of the upper urinary tract, the severity of atrophic parenchymal changes secondary to UPJ obstruction, and to identify potential external causes of HN (aberrant or segmental vessels, retrocaval ureter) [32, 33, 34].
Level of Evidence AGrade of Recommendation 2 Level of Evidence A (grade of recommendation – 2)
Comments: SCT provides information on the function of the affected kidney and the anatomy of the upper urinary tract and surrounding tissues. Attempts are being made to use computed tomography to assess renal function based on parenchymal tissue thickness. In the preoperative diagnosis of UPJ stenosis (obstruction), SCT has a sensitivity of 98% and a specificity of 100% [33]. In the preoperative diagnosis of ureterovascular conflict, SCT has a sensitivity of 91% and a specificity of 100% [34]. Currently, SCT is the leading radiological method for diagnosing HN.
Indications for SCT in pediatric patients must be strictly justified due to significant radiation exposure. The necessity of mandatory sedation (general anesthesia) due to the duration of the scan limits its use in young children. The effective dose is significantly higher compared to other imaging and radionuclide diagnostic modalities for urinary system disorders [35, 36]. When performing 4 scans per examination, the effective dose in infants is 4.5–6.2 mSv, in patients aged 3–7 years it is 6.5–9 mSv, in patients aged 8–12 years it is 8.8–14 mSv, and in adolescents it can reach 18 mSv [37].
Contraindications to multislice CT (MSCT): patient age under three months, severe impairment of renal concentrating capacity, intolerance to iodine-containing radiocontrast agents (ATC code V08A).
It is recommended to perform renal and urinary tract scintigraphy with calcium trisodium pentetate** in all patients with hydronephrosis to determine the secretory and excretory function of the affected and contralateral kidneys, as well as the elimination pattern of diagnostic radiopharmaceuticals (ATC code V09) from the upper urinary tract [19, 38, 39].
Level of Evidence AGrade of Recommendation 2 Level of Evidence A (grade of recommendation – 2)
Comments: differential (split) renal function (DRF) is calculated within 1–2 minutes after radiopharmaceutical administration and is considered normal when the DRF value is in the range of 45–55%. Renal parenchymal function is poor at a DRF of less than 20% and moderately reduced at a DRF of 29–39% [40]. Impaired urine outflow from the renal pelvis is assessed by T½ (elimination half-time of the radiopharmaceutical). Mainly in ureteropelvic junction obstruction (UPJO) and hydronephrosis (HN), an obstructive type of drainage curve is observed with a radiopharmaceutical half-elimination period of more than 40 minutes.
An important role in the diagnosis of obstructive urodynamic disorders is played by the kinetic parameter of radiopharmaceutical transfer – the cortical transit time (CTT). The normal CTT is 3 minutes after tracer injection during scanning using calcium trisodium pentetate**. Delayed CTT (resulting from decreased GFR) is a significant predictor of UPJO and the need for surgical intervention in children with unilateral hydronephrosis [41].
It is recommended to perform renal and urinary tract scintigraphy using the radiopharmaceutical diagnostic agent Technemag 99mTc in pediatric patients with hydronephrosis to determine the secretory and excretory function of the affected and contralateral kidneys, as well as the elimination pattern of the diagnostic radiopharmaceutical (ATC code V09) from the upper urinary tract, due to the immaturity of the glomerular apparatus [42, 43].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: the recommended time for diuretic renography is after 4–6 weeks of life. The optimal time for the first isotopic renal study is 3 months of age. In other age groups, a glomerular radiopharmaceutical – calcium trisodium pentetate** – is used for DMSA renal scintigraphy.
It is recommended to perform renal scintigraphy with loading tests (a drug from the sulfonamide group (ATC code C03CA) - for dosing regimen, see above) in children with moderate to severe unilateral or bilateral hydronephrosis (SFU III–IV, APD ≥ 15 mm) in whom vesicoureteral reflux has been excluded, as well as in patients with worsening hydronephrosis grade according to ultrasound data, to study upper urinary tract urodynamics under forced diuresis in order to differentiate UPJO from non-obstructive hydronephrosis [19, 38, 39].
Level of Evidence AGrade of Recommendation 2 Level of Evidence A (grade of recommendation – 2)
Comments: renal scintigraphy with loading tests (a drug from the sulfonamide group (ATC code C03CA)) is the most frequently used diagnostic method to detect the functional significance of urinary outflow disorders from the pelvicalyceal system. Test results can be affected by the patient's hydration status, reduced renal function (GFR <15 mL/min), pelvicalyceal system volume, and bladder filling degree at the time of the study [44]. It is recommended to perform the study under standard conditions (oral fluid intake before the examination, voiding prior to radiopharmaceutical administration). Bladder catheterization is performed only in case of bladder dysfunction and suspected vesicoureteral reflux.
Administration of a drug from the sulfonamide group (ATC code C03CA) 20 minutes after radiotracer injection is the most commonly used protocol for calcium trisodium pentetate. In pediatric patients, it is advisable to use the Technemag 99mTc protocol – where the drug from the sulfonamide group (ATC code C03CA) is administered simultaneously with the radiopharmaceutical, which shortens the study time.
Analysis of the half-elimination period (T1/2) of the radiopharmaceutical after diuretic administration is carried out according to standard criteria: T1/2 less than 10–15 min – no evidence of ureteral obstruction; T1/2 exceeding 20 minutes indicates severe UPJO; T1/2 in the range of 15–20 min makes the diuretic test result equivocal.
Since renal function immaturity leads to decreased radiopharmaceutical uptake, renal and urinary tract scintigraphy in pediatric patients is performed after 6–8 weeks of life, but may be performed earlier in patients with severe hydronephrosis and cortical thinning. Renal and urinary tract scintigraphy with functional tests is not indicated for the evaluation of low-grade hydronephrosis (SFU 1–2) with normal renal parenchyma and symmetrical kidney size.
The recommended time for renal scintigraphy with functional tests (a drug from the sulfonamide group (ATC code C03CA)) is after 4–6 weeks of life. The optimal time for the first isotopic renal study is 3 months of age. In other age groups, a glomerular radiopharmaceutical – calcium trisodium pentetate** – is used for DMSA renal scintigraphy.
It is recommended to perform static renal scintigraphy with Technetium [99mTc] succimer** in adult patients with hydronephrosis for a more accurate assessment of the functional activity of the renal parenchyma and the detection of focal or diffuse changes in obstructive hydronephrosis according to the SFU classification [35, 46–50].
GCR BLOE 2Grade of Recommendation B (Level of Evidence – 2)
Comments: is one of the main methods for detecting changes in the structural and functional state of the renal parenchyma, often in the absence of clinical and laboratory symptoms. DMSA scintigraphy is effective in assessing renal parenchymal function in the early stages of urodynamic disorders. The sensitivity and specificity of static renal scintigraphy with Technetium [99mTc] succimer in detecting sclerotic changes in the renal parenchyma are 88% and 84%, respectively.
The disadvantage of this method is its low informativeness in symmetrical renal damage and in patients with a solitary kidney.
It is recommended to perform magnetic resonance urography (MRU) with loading tests (a drug from the sulfonamide group (ATC code C03CA) - for dosing regimen, see above) in patients with hydronephrosis regardless of age to obtain more precise anatomical detail of the affected kidney, evaluate differential renal function, and study urodynamics under diuresis conditions [51–56].
Level of Evidence AGrade of Recommendation 2 Level of Evidence A (grade of recommendation – 2)
Comments: provides comprehensive morphological and functional information. Using various contrast-enhanced MRU modes with loading tests, it is also possible to image renal vessels and perform virtual ureterorenoscopy. For detecting pelvicalyceal system dilation, the sensitivity of MRI is 95–100%, specificity is 83–90%; in cases of UPJO, these figures are 92–100% and 80–95%, and for crossing vessels, 89–96% and 88–96%, respectively. Particular interest in this functional method in pediatric urology is primarily associated with the absence of ionizing radiation, unlike radiological imaging modalities. Despite the high informativeness of the method in diagnosing obstructive hydronephrosis, a significant limitation of MRI in younger patients is the necessity of mandatory sedation due to the duration of the study [36].
It is recommended to perform retrograde ureteropyelography in adult patients with hydronephrosis for clear visualization of the upper urinary tract on the affected side, in order to confirm the diagnosis, determine the anatomical state of the UPJ, precisely localize the obstruction, and determine the extent of the ureteral stricture zone [19].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: The indication is considered to be the lack of visualization of the ureter below the level of obstruction based on non-invasive imaging diagnostics. The study is important when planning revision surgeries in case of suspected ureteropyelostomy stricture.
It is recommended to perform antegrade pyeloureterography in patients with hydronephrosis regardless of age, if a nephrostomy drainage is present to visualize the upper urinary tract and to localize and determine the extent of the ureteral stricture [19].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
It is recommended to perform pyelomanometry (Whitaker test – antegrade pressure measurement in the upper urinary tract) in patients with hydronephrosis who have a nephrostomy tube to assess the contractility of the upper urinary tract [57].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: The Whitaker test is indicated for patients with a nephrostomy or when the results of other less invasive diagnostic tests are equivocal. The test involves measuring pressure in the pelvicalyceal system at a fixed infusion rate of 10 mL/min.
Interpretation of results:
— a difference of less than 15 cm of water column is considered normal;
— the presence of obstruction is confirmed when the difference is greater than 22 cm of water column;
— if the difference is more than 15 cm of water column, but less than 22 cm of water column, the result is considered borderline and the infusion rate is increased to 15 ml/min.
It is recommended to perform ureteroscopy in patients with hydronephrosis, regardless of age, to rule out ureteropelvic anastomosis stenosis after a prior reconstructive plastic surgery or when recurrent UPJ stenosis is suspected after percutaneous (transfistular) endopyelotomy [20].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: given the highly invasive nature of the study when planning subsequent endoscopic correction of the ureteropelvic anastomosis, it is advisable to perform ureteroscopy with a diatherapeutic purpose (simultaneous combination of anastomotic stenosis diagnosis and surgical correction).
The ability to pass a ureteroscope through the suspected narrowing into the renal pelvis does not rule out the absence of stenosis.
2.5 Other Procedures
No other diagnostic tests are available.
3. Treatment, including drug and non-drug therapies, diet therapy, and pain management
3.1 Medical treatment
Medical therapy is not of primary importance and plays an auxiliary role in preparing the patient for surgical treatment and preventing complications of hydronephrosis [62].
3.2 Surgical Treatment
The main goal of surgical treatment is to restore normal urine passage, preserve renal function, and prevent the progression of chronic pyelonephritis and renal parenchymal atrophy.
Treatment options for hydronephrosis secondary to pelviureteric junction obstruction (PUJO) in children and adults are generally similar and include a wide range of approaches. According to EAU/ESPU guidelines, early surgical correction of PUJO is indicated in children with grade III–IV hydronephrosis (SFU), an anteroposterior renal pelvis diameter >20 mm, differential renal function (DRF) <40%, and an obstructive drainage curve (T1/2 >20 min). For adult patients, the indication for reconstructive surgery is stage 2–3A hydronephrosis. Switching from active surveillance to pyeloplasty is recommended if DRF decreases by more than 10% during the follow-up period, the anteroposterior diameter of the pelvis increases, the grade of hydronephrosis (SFU) progresses, or symptoms (pain/UTI) appear [10].
It is recommended to perform open reconstructive surgeries to prevent renal loss in children with grade III–IV hydronephrosis (SFU) and adults with stage 2–3A hydronephrosis [19].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: open pyeloplasty, performed via an anterior extraperitoneal or lumbar approach, has long been considered the gold standard for treating UPJ stenosis and hydronephrosis. The efficacy of open plastic surgery is approximately 87-95%. Currently, the main drawbacks of this surgical intervention are considered to be high postoperative morbidity and a long incision length, which reduces the cosmetic outcome. Dismembered pyeloplasty (Anderson-Hynes procedure) is considered the gold standard of reconstructive surgery for hydronephrosis. The basic principle of the operation consists of excising the altered UPJ, and if necessary, the pathologically altered upper third of the ureter and part of the renal pelvis, followed by precise alignment of the anastomosed surfaces of the ureter and pelvis. However, this technique has not proven to be the primary treatment method for long or multiple strictures of the upper third of the ureter, nor for small intrarenal pelves.
For long strictures of the upper third of the ureter, it is most advisable to perform flap pyeloplasty to create a tension-free anastomosis with minimal devascularization of the UPJ. Such procedures include the Culp-DeWeerd spiral flap pyeloplasty and the Scardino-Prince vertical flap pyeloplasty.
In cases of high ureteral insertion, Foley Y-V plasty or Albarran-Lichtenberg pyeloplasty can be performed. Studies comparing the Foley technique with the Anderson-Hynes procedure performed under similar conditions noted a significant reduction in intraoperative time and greater ease of intracorporeal suturing in the Y-V group, with comparable surgical outcomes [63]. Another study comparing the success of the Anderson-Hynes operation and Foley Y-V plasty noted that success was slightly higher in the former group, but the difference was not statistically significant [64].
The presence of a vasoureteral vessel as a possible cause of hydronephrosis requires surgery involving the simultaneous resection of the narrowed ureteral segment and elimination of this conflict. The most popular approach is the Anderson-Hynes antevessel pyeloplasty.
In adult patients, the upper urinary tracts are drained postoperatively with a stent (double-pigtail ureteral stent for pyeloplasty) for 4-6 weeks. There is no consensus regarding the method of stent placement (double-pigtail ureteral stent for pyeloplasty)—whether retrograde or antegrade [65]. While studies on stenting-free pyeloplasty exist, upper urinary tract drainage is mandated in patients with a solitary kidney, long strictures of the upper third of the ureter, significant intraoperative hemorrhage from the anastomosed surfaces, and patients with ureteritis [66].
It is recommended to perform laparoscopic and retroperitoneoscopic reconstructive surgeries to prevent renal loss in children with grade III–IV hydronephrosis (SFU) and adults with stage 2–3A hydronephrosis [19].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: currently, laparoscopic pyeloplasty (LP, first performed in 1993 by Schuessler et al.) is considered the gold standard for treating hydronephrosis. The main advantages of the technique are insignificant blood loss, low postoperative morbidity, good cosmetic outcomes, and results comparable to open pyeloplasty. This surgical approach has proven effective in both children <1 year of age and elderly patients (>70 years) [67, 68]. LP is also successfully used in patients with a horseshoe kidney [6]. In large studies, the efficacy of the technique ranges from 85 to 100% [69].
The surgery can be performed transperitoneally or extraperitoneally. Studies comparing these approaches have revealed no differences in postoperative functional outcomes; however, retroperitoneoscopic pyeloplasty requires more operative time [70, 71].
Intraoperatively, the upper urinary tracts are drained with a stent (double-pigtail ureteral stent for pyeloplasty) for 4-6 weeks. There is no consensus regarding the method of stent placement (double-pigtail ureteral stent for pyeloplasty)—whether retrograde or antegrade [65].
It is recommended to perform robot-assisted reconstructive surgeries to prevent renal loss in children with grade III–IV hydronephrosis (SFU) and adults with stage 2–3A hydronephrosis [19].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: robotic systems significantly mitigate the disadvantages of laparoscopic techniques through 3D visualization, tremor filtration, and 5 degrees of instrument articulation. However, disadvantages include the lack of tactile feedback and high economic costs. Clinical trials have demonstrated the safety and efficacy of the technique, although no differences in functional outcomes or complication rates compared to LP were identified [72, 73]. Studies comparing open and robot-assisted pyeloplasty in children have shown that the latter group has a significantly shorter postoperative hospital stay, lower postoperative morbidity, and less intraoperative blood loss [74]. Furthermore, studies have shown that during a 2-year follow-up of patients after robot-assisted pyeloplasty, only 5% of patients required reoperation for anastomotic stenosis, compared to 13% of patients who underwent traditional open LP [75].
Intraoperatively, the upper urinary tracts are drained with a stent (double-pigtail ureteral stent for pyeloplasty) for 4-6 weeks. There is no consensus regarding the method of stent placement (double-pigtail ureteral stent for pyeloplasty)—whether retrograde or antegrade [65].
It is recommended to perform minimally invasive endoscopic surgeries in patients with UPJ stenosis and hydronephrosis to prevent renal loss [19].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
Comments: percutaneous (transfistular) endopyelotomy was first described in 1984 by Ramsay et al. The advantages of this surgical approach include a reduced postoperative hospital stay and rapid postoperative recovery. However, the functional outcomes of this minimally invasive technique are inferior compared to open, laparoscopic, and robot-assisted pyeloplasty. Studies have shown that percutaneous (transfistular) endopyelotomy can be effective in 65–93% of cases [76]. However, with proper patient selection, this technique can achieve clinical and functional efficacy. Studies have demonstrated that patients with early hydronephrosis (grade 2 according to Lopatkin) and preserved renal function have good surgical outcomes compared to patients with pronounced hydronephrosis (grade 3A according to Lopatkin). It should be kept in mind that for stenoses exceeding 2 cm in length, the outcomes of percutaneous (transfistular) and transurethral endopyelotomy may be unfavorable [77]. Endopyelotomy is rarely used in pediatric patients.
Balloon dilation can serve as an alternative endoscopic method. Balloon dilation is most effective when ureteropelvic junction stenosis is detected, provided it is performed within the first 2–3 months after the primary reconstructive surgery. High efficacy may be due to the absence of dense connective tissue in the stricture zone.
High-pressure endoscopic balloon dilation is also used for the minimally invasive treatment of ureteropelvic junction (UPJ) stenosis in patients during the first years of life (up to 18 months), who are characterized by insufficient maturation of the tissue structures of the renal pelvis and UPJ. The rate of positive results for balloon dilation is 70–80% [78-80].
The efficacy of the technique is slightly lower compared to open surgical interventions, but it surpasses them in terms of patient compliance and low invasiveness.
It is recommended to perform nephrectomy in patients with terminal stage 3B hydronephrosis in order to eliminate the non-functioning organ [19].
Level of Recommendations C Level of Evidence 5Level of recommendations C (level of evidence – 5).
Comments: nephrectomy may be performed in symptomatic patients with impaired renal function (differential renal function less than 15-20%) or a non-functioning kidney, or in the absence of technical feasibility for repeated reconstructive surgeries. This surgical procedure should be considered only if the function of the contralateral kidney is preserved.
It is recommended to perform percutaneous nephrostomy (PCN) or placement of an internal stent (double-pigtail ureteral stent for pyeloplasty) in patients with UPJ stenosis and hydronephrosis for the following purposes:
o Prevention of exacerbation of chronic pyelonephritis;
o Prevention of the progression of chronic kidney disease in bilateral processes or hydronephrosis of a solitary anatomical or functioning kidney;
o Relief of pain symptoms;
o Resolving the choice between nephrectomy and organ-sparing surgery [13, 22, 59, 81].
LoR CGoE 4Level of Recommendation C (Level of Evidence – 4)
Comments: in terminal stages of hydronephrosis, when it is necessary to resolve the choice between nephrectomy and organ-sparing surgery, renal drainage is performed. 1-2 weeks after drainage, the excretory and concentrating function of the affected kidney is examined (if a nephrostomy drainage was placed) and dynamic renal scintigraphy is performed.
4. Medical Rehabilitation and Sanatorium-Resort Treatment
Specific recommendation is not required
5. Prevention and Dispensary Observation
Active surveillance is recommended for all postnatal patients with renal function > 40% and anteroposterior renal pelvis diameter < 15 mm in order to timely identify the need for surgical treatment [1, 12, 22, 23, 59].
LoR CGoE 4Level of Recommendation C (Level of Evidence – 4)
Comments: the conservative management strategy for newborns and infants is based on the possibility of grade I-II hydronephrosis (SFU classification) to spontaneously regress within the first 12-14 months of life in 65% of cases [60]. Hydronephrotic transformation in these cases is associated with transient maturation dysfunction of the structural elements of the renal pelvis/ureter (due to delayed and heterochronic maturation).
Patient monitoring is accompanied by regular renal ultrasound examinations; for adult patients, isotope studies with 99mTc-Technemag (or Technetium [99mTc] succimer) are recommended. Ultrasound monitoring is performed once every 3 months during the first year of life to assess the dynamics of renal retention changes. In the absence of negative ultrasound dynamics, it is recommended to perform it once every 6 months, and renal scintigraphy with 99mTc-Technemag to assess renal parenchyma function once a year. It is possible to perform ultrasound with a diuretic test (studying the dynamics of the anteroposterior pelvic diameter and resistive index [RI] during forced diuresis), study the levels of biochemical markers of parenchymal damage (transforming growth factor beta 1 [TGFβ1], epidermal growth factor [EGF], endothelin-1 [ET-1], monocyte chemoattractant protein-1 [MCP-1], low-molecular-weight β2-microglobulin, and tubular enzymes [γ-glutamyltransferase, alkaline phosphatase, N-acetyl-β-D-glucosaminidase, etc.]) [61]. If the grade of hydronephrotic transformation increases, dynamic renal scintigraphy with 99mTc-Technemag with a diuretic test is performed.
It is recommended for all patients with hydronephrosis to undergo a renal ultrasound once every 6 months, and renal and urinary tract scintigraphy once 1 year after surgical treatment to assess disease dynamics [13].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
It is recommended for all patients with hydronephrosis to undergo follow-up care by a local urologist for 3 years after surgery. If residual pelvicalyceal system dilation is present, follow-up care may be prolonged to assess disease dynamics [21].
GRS CLOE 5Grade of Recommendation Strength C (Level of Evidence – 5)
If patients have pelvicalyceal system dilation that does not correspond to the postoperative timeline, it is recommended to perform computed tomography (CT) and ureteroscopy to rule out ureteropelvic junction stenosis [22, 59].
LoR CGoE 4Level of Recommendation C (Level of Evidence – 4)
6. Organization of Medical Care
Indications for planned hospitalization:
1. Confirmed ureteropelvic junction stenosis, stage 2-3 hydronephrosis based on instrumental diagnostic methods for performing reconstructive surgery.
Indications for emergency hospitalization:
1. Acute obstructive pyelonephritis
Indications for patient discharge from the hospital:
1) No need for inpatient observation and treatment after surgery, provided adequate stent patency (double-pigtail ureteral stent for pyeloplasty).
2) Absence of purulent-septic complications after the surgical intervention
3) Absence of thromboembolic complications after the surgical intervention
4) Unobstructed urine passage through the upper urinary tract achieved as a result of the surgical intervention according to ultrasound or (if necessary) CT data
7. Additional Information
No additional information available
Criteria for Evaluating the Quality of Medical Care
№ | Quality criteria | Performance |
|---|---|---|
1. | Reconstructive surgery performed in children with grade III-IV hydronephrosis (SFU) | yes/no |
2. | Reconstructive surgery performed in adult patients with stage 2-3A hydronephrosis (N.A. Lopatkin classification) | yes/no |
3. | Organ-removing surgery performed in patients with stage 3B hydronephrosis (N.A. Lopatkin classification) | yes/no |
4. | Renal ultrasound performed 6 months after reconstructive surgery | yes/no |
5. | Renal ultrasound performed 1 year after reconstructive surgery | yes/no |
6. | Renal scintigraphy performed 1 year after reconstructive surgery | yes/no |
7. | Follow-up by a local urologist conducted for 3 years after reconstructive surgery | yes/no |
References
Show references
1. Hashim Hashim, Christopher R.J. Woodhouse Ureteropelvic Junction Obstruction EUROPEAN UROLOGY SUPPLEMENTS 11 (2012) 25–32 doi:10.1016/j.eursup.2012.01.004
2. Maizels M, Stephens FD. Valves of the ureter as a cause of primary obstruction of the ureter: anatomic, embryologic and clinical aspects. J Urol 1980;123:742–7.
3. Hosgor M, Karaca I, Ulukus C, et al. Structural changes of smooth muscle in congenital ureteropelvic junction obstruction. J Pediatr Surg 2005;40:1632–6.
4. Lowe FC, Marshall FF. Ureteropelvic junction obstruction in adults. Urology 1984;23:331–5.
5. Adey GS, Vargas SO, Retik AB, et al. Fibroepithelial polyps causing ureteropelvic junction obstruction in children. J Urol 2003;169: 1834–6.
6. Lallas CD, Pak RW, Pagnani C, et al. The minimally invasive management of ureteropelvic junction obstruction in horseshoe kidneys. World J Urol 2011;29:91–5.
7. Sizonov V.V. Diagnosis of pelvoureteral junction obstruction in children. Urology Journal (Vestnik urologii). 2016; (4):56-120 (in Russ.)
8. Capello SA, Kogan BA, Giorgi LJ et al. Prenatal ultrasound has led to earlier detection and repair of ureteropelvic junction obstruction. J Urol. 2005; 174:1425–1428
9. Cohen B, Goldman SM, Kopilnick M, Khurana AV, Salik JO. Ureteropelvic junction obstruction: its occurrence in 3 members of a single family. J Urol 1978;120:361–4.
10. Pediatric urology guidelines, ESPU. 2015; 41-44.; Pediatric urology guidelines, European Association of Urology. 2018; 49-53
11.Thomas DFM. Upper tract obstruction. In: Thomas DFM, Duffy PG, Rickwood AMK, editors. Essentials of paediatric urology. Ed. 2. London, UK: Informa Healthcare; 2008. P. 73–92.
12. Nonomura K, Yamashita T, Kanagawa K et al. Management and outcome of antenatally diagnosed hydronephrosis // Int. J. Urol. — 1994 — Vol. 1 — P. 121—128.
13. Lopatkin NA. Guidelines on urology // Moscow: Meditsina, 1998. — Vol. 2. — P. 190. (in Russ.)
14. Onen A. An alternative grading system to refine the criteria for severity of hydronephrosis and optimal treatment guidelines in neonates with primary UPJ-type hydronephrosis. J. Pediatr. Urol. 2007; 3 (3): 200-205. Doi: 10.1016/j.jpurol.2006.08.002
15. Fernbach SK, Maizels M, Conway JJ. Ultrasound grading of hydronephrosis: Introduction to the system used by the Society for Fetal Urology. Pediatr Radiol 1993; 23: 478-480
16. Grignon A, Filion R, Filiatrault D, Robitaille P, Homsy Y, Boutin H, et al. Urinary tract dilatation in utero: classifica- tion and clinical applications. Radiology. 1986;160: 645-7
17. Deryugina LA. Antenatal diagnosis of congenital urinary tract diseases and rationale for postnatal management tactics in children. Dr. med. sci. diss. — M, 2008. (in Russ.)
18. Nguyen, H.T., Herndon, C.D., Cooper C., et al. The Society for Fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis. J Pediatr Urol. 2010; 6: 212–231. Doi: 10.1016/j.jpurol.2010.02.205.
19. Wojciechowska J, Dembowski J, Zdrojowy R, Szydełko T. Hydronephrosis in the course of ureteropelvic junction obstruction: An underestimated problem? Current opinions on the pathogenesis, diagnosis and treatment. Adv Clin Exp Med. 2017 Aug;26(5):857-864. Doi: 10.17219/acem/59509.
20. Glybochko PV, Alyaev YuG. Hydronephrosis. M: GEOTAR-Media, 2011, 32 p. (in Russ.)
21. Urology, national guidelines / edited by Academician of RAMS N.A. Lopatkin. Moscow, "GEOTAR-Media", 2009, p. 370. (in Russ.)
22. Grigoryan VA. Surgical treatment of hydronephrosis: Dr. med. sci. diss. — M, 1998. (in Russ.)
23. Heinlen JE, Manatt CS, Bright BC, Kropp BP, Campbell JB, Frimberger D. Operative versus nonoperative management of ureteropelvic junction obstruction in children. Urology 2009; 73:521–5
24. Ebel KD. Uroradiology in the fetus and newborn: diagnosis and follow-up of congenital obstruction of the urinary tract. Pediatr Radiol 1998;28(8):630–5. http://www.ncbi.nlm.nih.gov/pubmed/9716640
25. Ismaili K, Avni FE, Hall M. Results of systematic voiding cystourethrography in infants with antenatally diagnosed renal pelvis dilatation. J Pediatr. 2002; 141:21–4
26. Ward VL. Patient dose reduction during voiding cystourethrography. Pediatr Radiol. 2006; 36:168-72
27. Herndon C.D., McKenna P.H., Kolon T.F. et al. A multicenter outcomes analysis of patients with neonatal reflux presenting with prenatal hydronephrosis. J Urol. 1999; 162: 1203-1208. DOI: 10.1016/S0022-5347(01)68134-5
28. Capolicchio J.P., Braga L.H., Szymanski K.M. Canadian Urological Association/Pediatric Urologists of Canada guidelines on the investigation and management of antenatally detected hydronephrosis. Can Urol Assoc J. 2018;12(4):85-92. https://doi.org/10.5489/cuaj.5094
29. Mitterberger M, Pinggera GM, Neururer R, et al. Comparison of contrast-enhanced color Doppler imaging (CDI), computed tomography (CT), and magnetic resonance imaging (MRI) for the detection of crossing vessels in patients with ureteropelvic junction obstruction UPJO). Eur Urol.2008 ; 53:12 5 4 –126 0
30. Vasilyev AYu. Diagnostic radiology in pediatrics. / AYu Vasilyev. GEOTAR-Media. 2009. – P. 217. (in Russ.)
31. Talner LB. Specific disorders of the urinary tract. In: Clinical Urography, Pollack HM, Dyer RB, editors. By: WB Saunders: Philadelphia. 2000
32. Ramaswamy K, Marien T, Mass A, Stifelman M, Shah O. Simplified approach to estimating renal function based on computerized tomography. Can J Urol. 2013; 20:6833–6839.
33. Kasiteridi IG. Comparative evaluation of modern diagnostic methods in hydronephrosis. Cand. med. sci. diss. — M., 2005. (in Russ.)
34. Khaira H.S., Platt J.F., Cohan R.H. et al. Helical computed tomography for identification of crossing vessels in ureteropelvic junction obstruction-comparison with operative findings. Urology. 2003; 62 (1); 35-39.
35. Krzemien, G. Importance of different imaging methods in diagnosis of significant urodynamically uretropelvic junction obstruction in children with congenital hydronephrosis. Pol Merkur Lekarski. 2008; 24(4): 41- 45.
36. Thukral, B. B. Problems and preferences in pediatric imaging. Indian J Radiol Imaging. 2015; 25 (4):359-364.
37. Towbin R., Baskin K. Pediatric Interventional Radiology. Cambridge University Press. 2015; 493
38. Esmaeili M, Ghane F, Alamdaran A. Comparison Between Diuretic Urography (IVP) and Diuretic Renography for Diagnosis of Ureteropelvic Junction Obstruction in Children. Iran J Pediatr. 2016 Feb;26(1):e4293. Doi: 10.5812/ijp.4293. Epub 2016 Jan 30.
39. Taylor AT, Brandon DC, de Palma D. et al. SNMMI Procedure Standard/EANM Practice Guideline for Diuretic Renal Scintigraphy in Adults With Suspected Upper Urinary Tract Obstruction. Semin Nucl Med. 2018 Jul;48(4):377-390. Doi: 10.1053/j.s
40. Prigent A., Cosgriff P., Gates G.F. et al. Consensus report on quality control of quantitative measurements of renal function obtained from renogram: International Consensus Committee from the Scientific Committee of Radionuclides in Nephrourology. Semin. Nucl. Med. 1999; 91:46–59.
41. Lee J.N., Kang J.K., Jeong S.Y. et al. Predictive value of cortical transit time on MAG3 for surgery in antenatally detected unilateral hydronephrosis caused by ureteropelvic junction stenosis. J Pediatr Urol. 2018;14(1):55.e1-55.e6. doi: 10.1016/j.jpurol.2017.08.009
42. O´ Reilly P., Aurell M., Britton K. et al. Consensus on diuresis renography for investigating the dilated upper urinary tract. J. Nucl. Med. 1996; 37 (11):1872-76.
43. Gordon I., Piepsz A., Sixt R. Auspices of Paediatric Committee of European Association of Nuclear Medicine. Guidelines for standard and diuretic renogram in children. Eur. J. Nucl. Med. Mol. Imaging. 2011; 38 (6):1175- 88. DOI 10.1007/s00259-011-1811-36
44. Rao NP, Srirangam SJ, Preminger GM. Nuclear Medicine Investigations. Urological Tests in Clinical Practice. London: Springer-Verlag; 2007. P. 132-62.
45. Majd M, Bar-Sever Z, Santos AI, De Palma D. The SNMMI and EANM Procedural Guidelines for Diuresis Renography in Infants and Children. J Nucl Med. 2018;59(10):1636-1640. Doi: 10.2967/jnumed.118.215921
46. Piepsz A, Sixt R., Gordon I. Performing renography in children with antenatally detected pelvi-ureteric junction stenosis: errors, pitfalls, controversies. Q. J. Nucl. Med. Mol. Imaging. 2010; 54(4):350-62
47. Pavlov, A.Yu., Sabirzyanova Z.R., Fomin D.K. et al. [Current capabilities of diagnostic imaging in congenital malformations of the urinary system in children]. Russian Electronic Journal of Radiology. 2011; 1 (2): 135-136. (In Russ.)
48. Mendichovszky I. Nuclear Medicine in Pediatric Nephro-Urology: An Overview. Semin Nucl Med. 2017; 47 (3): 204-228.
49. Ritchie G. Wilkinson A.G., Prescott R.J. Comparison of differential renal function using technetium-99m mercaptoacetyltriglycine (MAG3) and technetium-99m dimercaptosuccinic acid (DMSA) renography in a paediatric population. Ped. Radiol. 2008; 38(8):857-62. Doi: 10.1007/s00247-008-0908-8.
50. Yatsyk S.P., Zubovskiy G.A., Fomin D.K. [Method for assessing renal parenchyma viability]. Patent RF No. 2270605. Bull. 2006; No. 6. (In Russ.)
51. Gromov, A.I. [Diagnostic Imaging and Therapy in Urology: National Guidelines]. / A.I. Gromov, V.M. Buylov, S.K. Ternovoy. GEOTAR-Media. – 2011. – P. 544. (In Russ.)
52. Cerwinka, W. H., Grattan-Smith J.D., Kirsch A.J. Magnetic resonance urography in pediatric urology. J Pediatr Urol. 2008; 4(1): 74-82.
53. Arlen, A.M. Magnetic resonance urography for diagnosis of pediatric ureteral stricture / A.M. Arlen // J Pediatr Urol. – 2014. – Vol. 10. – No. 5. – P. 792-798.
54. Ritter, L. Significance of MR angiography in the diagnosis of aberrant renal arteries as the cause of ureteropelvic junction obstruction in children. Rofo. 2015; 187(1): 42-48.
55. Sharma A. Comparison of intravenous urography and magnetic resonance urography in preoperative evaluation of pelvi-ureteric junction obstruction in children. J Indian Assoc Pediatr Surg. 2016; 21 (4):169-174.
56. Hwang, S.I. Effectiveness of MR urography in the evaluation of kidney which failed to opacify during excretory urography: comparison with ultrasonography. Korean J Radiol. 2000; 1(3):152-158.
57. Johnston RB, Porter C. The Whitaker test. Urology journal. 2014;11(3):17 27–17 3 0.
58. Ringert R.H., Kallerhoff M. Leitlinie zur Diagnostik der Harntransportstörungenin der Kinderurologie // Urologe A. — 1998. — Vol. 37. — P. 573–574.
59. Enikeev, M.E. [Hydronephrosis: modern technologies in diagnosis and treatment]. Diss. Dr. Med. Sci. — Moscow, 2008. (In Russ.)
60. Lee RS, Cendron M, Kinnamon DD, et al. Antenatal hydronephrosis as a predictor of postnatal outcome: A meta-analysis. Pediatrics 2006; 118:586-93. DOI: 10.1542/peds.2006-0120
61. Alberti C. Congenital ureteropelvic junction obstruction: physiopathology, decoupling of tout court pelvic dilatation-obstruction semantic connection, biomarkers to predict renal damage evolution. Eur. Rev. Med. Pharmacol. Sci. 2012; 16(2):213-9.
62. Belman A.B. A perspective on vesicoureteral reflux // Urol. Clin. North. Am. — 1995. — Vol. 22. — P. 139–150.
63. Szydelko T, Kasprzak J, Apoznanski W, et al. Comparison of dismembered and nondismembered Y-V laparoscopic pyeloplasty in patients with primary hydronephrosis. J Laparoendosc Adv Surg Tech A .2010 ; 20 (1):7–12 .
64. Szydelko T, Kasprzak J, Lewandowski J, Apoznanski W, Dembowski J. Dismembered laparoscopic Anderson-Hynes pyeloplasty versus nondismembered laparoscopic Y-V pyeloplasty in the treatment of patients with primary ureteropelvic junction obstruction: A prospective study. Journal of Endourology/Endourological Society. 2012 ; 2 6 ( 9 ) :116 5 –117 0 .
65. Arumainayagam N, Minervini A, Davenport K, et al. Antegrade versus retrograde stenting in laparoscopic pyeloplasty. J Endourol. 2008;22:671–674.
66. Shalhav AL, Mikhail AA, Orvieto MA, Gofrit ON, Gerber GS, Zorn KC. Adult stentless laparoscopic pyeloplasty. JSLS. 2007;11: 8–13.
67. Giri SK, Murphy D, Costello AJ, Moon DA. Laparoscopic pyeloplasty outcomes of elderly patients. J Endourol. 2011;25:251–256.
68. Metzelder ML, Schier F, Petersen C, Truss M, Ure BM. Laparoscopic transabdominal pyeloplasty in children is feasible irrespective of age. J Urol. 2006 ;175: 688–691.
69. Autorino R, Eden C, El-Ghoneimi A, et al. Robot-assisted and laparoscopic repair of ureteropelvic junction obstruction: A systematic review and meta-analysis. Eur Urol. 2014; 65:430–452.
70. Shoma AM, El Nahas AR, Bazeed MA. Laparoscopic pyeloplasty: A prospective randomized comparison between the transperitoneal approach and retroperitoneoscopy. J Urol. 2007; 178:2020–2024; discussion 2024.
71. Wu Y, Dong Q, Han P, Liu L, Wang L, Wei Q. Meta-analysis of transperitoneal versus retroperitoneal approaches of laparoscopic pyeloplasty for ureteropelvic junction obstruction. J Laparoendosc Adv Surg Tech A .2012; 22(7):658–662.
72. Uberoi J, Disick GI, Munver R. Minimally invasive surgical management of pelvic-ureteric junction obstruction: Update on the current status of robotic-assisted pyeloplasty. BJU Int. 2009; 10 4:1722–1729.
73. Braga LH, Pace K, DeMaria J, Lorenzo AJ. Systematic review and meta-analysis of robotic-assisted versus conventional laparoscopic pyeloplasty for patients with ureteropelvic junction obstruction: Effect on operative time, length of hospital stay, post-operative complications, and success rate. Eur Urol. 2009; 56:848–857.
74. Chang SJ, Hsu CK, Hsieh CH, Yang SS. Comparing the efficacy and safety between robotic-assisted versus open pyeloplasty in children: A systemic review and meta-analysis. World J Urol.2015;33(11):1855 –1865.
75. Lucas SM, Sundaram CP, Wolf JS, et al. Factors that impact the outcome of minimally invasive pyeloplasty: Results of the Multi-institutional Laparoscopic and Robotic Pyeloplasty Collaborative Group. J Urol.2012;187: 522–527.
76. Manikandan R, Saad A, Bhatt RI, Neilson D. Minimally invasive surgery for pelviureteral junction obstruction in adults: A critical review of the options. Urology.2005;65:422–432.
77. Lam JS, Cooper KL, Greene TD, Gupta M. Impact of hydronephrosis and renal function on treatment outcome: Antegrade versus retrograde endopyelotomy. Urology.2003; 61:1107-1111.
78. Ning Xu, Shao-Hao Chen, Xue-Yi Xue et al. Comparison of Retrograde Balloon Dilatation and Laparoscopic Pyeloplasty for Treatment of Ureteropelvic Junction Obstruction: Results of a 2-Year Follow-Up. PLOS ONE. 2016;11(3):e0152463. Journal. Pone.0152463.
79. Angulo JM, Parente A, Romero RM. Et al. Management of ureteropelvic juncti on obstruction with high-pressureballoon dilatation: long-term outcome in 50 children under 18 months of age. Urology. 2013;82(5):1138-43. Urology.2013.04.072.
80. Zorkin S.N., Gubarev V.I., Salnikov V.Yu. et al. High-pressure endoscopic balloon dilation as a method of treatment of pelviureteric junction obstruction in children. Urology Herald. 2017; 5(2):5-11. (In Russ.) DOI: 10.21886/2308-6424-2017-5-2-5-11.
81. Gupta DK1, Chandrasekharam VV, Srinivas M, Bajpai M. Percutaneous nephrostomy in children with ureteropelvic junction obstruction and poor renal function. Urology. 2001 Mar;57(3):547-50.
Appendix A1. Working Group Composition
1. Mikhail E. Enikeev – MD, Professor, Institute of Urology and Human Reproductive Health, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)
2. Vera V. Rostovskaya – MD, Professor, Department of Pediatric Surgery and Urology-Andrology named after L.P. Alexandrov, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)
3. Leonid M. Rapoport – MD, Professor, Institute of Urology and Human Reproductive Health, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)
4. Vagarshak A. Grigoryan – MD, Professor, Institute of Urology and Human Reproductive Health, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)
5. Mikhail V. Lobanov – PhD, Urologist, Urology Clinic, I.M. Sechenov First Moscow State Medical University of the Russian Ministry of Health (Sechenov University)
6. Igor V. Semenyakin – MD, Associate Professor, Department of Urology, A.I. Evdokimov Moscow State University of Medicine and Dentistry
Conflict of interest:
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 for these clinical guidelines: specialists with higher medical education in the following specialties:
1. Urology
2. Internal Medicine
3. General Practice (Family Medicine)
4. Surgery
5. Obstetrics and Gynecology
6. Anesthesiology and Intensive Care
7. Pediatric Urology-Andrology
8. Pediatrics
In these clinical guidelines, all data are ranked by level of reliability (evidence) depending on the quantity and quality of studies on the issue.
1. Level of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)
LoE | Definition |
|---|---|
1. | Systematic reviews of studies with reference standard control or systematic reviews of randomized controlled trials with meta-analysis |
2. | Individual studies with reference standard control, or individual randomized controlled trials and systematic reviews of studies of any design except randomized controlled trials, using meta-analysis |
3. | Studies without consecutive reference standard control or studies with a reference standard not independent of the test method, or non-randomized comparative studies, including cohort studies |
4. | Non-comparative studies, case report |
5. | Only justification of mechanism of action or expert opinion is available |
2. Level of Evidence (LoE) grading scale for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitative interventions)
LoE | Definition |
|---|---|
1. | Systematic review of randomized controlled trials with meta-analysis |
2. | Individual randomized clinical trials and systematic reviews of studies of any design, excluding randomized clinical trials, with meta-analysis |
3. | Non-randomized comparative studies, including cohort studies |
4. | Non-comparative studies, case reports or case series, case-control studies |
5. | Only justification of the mechanism of action of the intervention (preclinical studies) or expert opinion is available |
3. Grade of Recommendation (GoR) scale for prevention, diagnostic, treatment, and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitative interventions)
GOR | Definition |
|---|---|
A | Strong recommendation (all considered efficacy criteria (outcomes) are important, all studies are of high or acceptable methodological quality, and their conclusions on the outcomes of interest are consistent) |
C | Conditional recommendation (not all considered efficacy criteria (outcomes) are important, not all studies are of high or acceptable methodological quality, and/or their conclusions on the outcomes of interest are inconsistent) |
C | Weak recommendation (lack of adequate quality evidence (all considered efficacy criteria (outcomes) are unimportant, all studies are of low methodological quality, and their conclusions on the outcomes of interest are inconsistent) |
Procedure for updating clinical guidelines.
The guideline update mechanism provides for their systematic review—at least once every three years or upon the emergence of new information on the management tactics of patients with this disease. The decision to update is made by the Russian Ministry of Health based on proposals submitted by professional medical non-profit organizations. The submitted proposals must take into account the results of a comprehensive assessment of medicinal products and medical devices, as well as the results of clinical approbation.
Appendix A3. Reference Materials
These clinical guidelines were developed taking into account the following regulatory legal documents:
1. European Association of Urology (EAU) Clinical Guidelines.
2. Order of the Russian Ministry of Health No. 907n dated November 12, 2012, “On approval of the procedure for providing medical care to the adult population in the specialty 'urology'”.
Appendix B. Physician Action Algorithms
Appendix C. Patient Information
The patient is informed about the clinical presentation of the disease, various treatment methods, and their potential outcomes. The choice of treatment method should be made as a result of this discussion after the patient has had the opportunity to ask all questions of interest.
The patient must be informed about the possible course of the disease, risks associated with the progression of hydronephrosis and renal parenchymal atrophy, up to the loss of renal function.
The patient should be informed about the symptoms and various complications of hydronephrosis, including secondary stone formation, exacerbations of acute pyelonephritis, arterial hypertension, and the development of end-stage renal parenchymal changes.
Special attention should be paid to patients with hydronephrosis of a solitary kidney. They must be warned of the need for continuous follow-up due to the risk of anuria and acute renal failure.
The patient must be informed about the possible risks and consequences of both surgical treatment (pyeloplasty, percutaneous [through a nephrostomy tract] endopyelotomy, transurethral endopyelotomy, and others) and active surveillance. The patient should be informed about the low efficacy of medical therapy.
Following the surgical procedure, it is necessary to explain to the patient the timing for stent removal (double-J ureteral stent for pyeloplasty) and subsequent follow-up monitoring. The timeframe for the recovery of normal urodynamics must be explained; the possibility of residual pelvicalyceal dilation on ultrasound should be clarified, which in itself does not yet signify disease recurrence.
Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools
None provided.