Basic principles and pre-operative preparation
Any interventional procedure begins with establishing reliable vascular access. A crucial step prior to manipulation is a rigorous pre-operative assessment.
Performing a patient safety checklist is strictly mandatory. This step allows for the early identification of critical risk factors that could affect the outcome of the intervention. Specifically, before the procedure, the physician must:
- Determine the presence of allergic reactions to contrast media.
- Clarify the status of anticoagulant therapy.
- Assess renal function to rule out renal impairment.
The optimal approach, recognized as the gold standard in interventional radiology, is performing the procedure under ultrasound (US) guidance. This utilizes the single wall puncture technique (anterior wall only).
Instrumentation: Seldinger needle and introducers
The primary instrument for entering the lumen of the target vessel is a modern modification of the Seldinger Needle (Seldinger Needle). It is a hollow metal needle of 18-G gauge. The main technical rule when working with it is the strict orientation of the tip: the needle bevel must be directed strictly anteriorly during every puncture attempt.
The access creation technique is as follows:
- After successfully entering the artery, a special guidewire is inserted through the needle lumen.
- Once the guidewire is inside the vascular bed, the puncture needle is removed.
- The remaining guidewire provides direct access: a catheter or sheath is introduced into the artery over it as a guiding axis.
Important contraindication: It is strictly forbidden to use hydrophilic guidewires in combination with beveled Seldinger needles. This restriction is due to the high risk of accidentally shearing the outer coating of the guidewire with the sharp edge of the needle.
Access selection: antegrade or retrograde
The choice of puncture direction directly affects procedural safety. Antegrade puncture is considered technically more challenging compared to retrograde access. It is associated with an increased complication rate, which is particularly evident in obese patients.
A critical anatomical landmark is the inguinal ligament. Performing a puncture above this level carries a serious risk of retroperitoneal haematoma (retroperitoneal haematoma). Due to the high danger of this complication, puncture above the inguinal ligament is often considered a direct contraindication to antegrade access.
As safer alternatives, specialists suggest two options:
- Classic alternative: contralateral puncture followed by catheter advancement across the aortic bifurcation (the so-called cross-over technique). Many specialists consider this method significantly safer.
- Alternative in obesity: direct puncture of the superficial femoral artery under continuous ultrasound guidance. This method is a highly safe alternative for patients with pronounced obesity, especially if the procedure concludes with the use of special closure devices. Ultrasound guidance plays a key role here, helping to overcome many technical difficulties of antegrade access.
Ultrasound anatomy and navigation
The use of echographic guidance radically increases the precision of manipulations. On the ultrasound screen, the physician clearly visualizes the entire needle trajectory and the moment its tip enters the lumen of the common femoral artery (common femoral artery, AFC). The common femoral vein (common femoral vein, VFC) is always located nearby as a crucial topographical landmark.
Subsequent advancement of the guidewire also requires strict ultrasound guidance. The specialist must visually monitor that the guidewire advances strictly into the superficial femoral artery (superficial femoral artery, SFA). This helps avoid a common error—unintentional entry of the instrument into the profunda femoris artery (profunda femoris artery, PFA).
Briefly: answers to topical questions
What complications can occur during arterial puncture?
The following complications may occur during arterial puncture:
- Access site haemorrhage (Access site haemorrhage) — in most cases successfully managed with manual compression.
- False aneurysms (False aneurysms) — occur with a frequency of less than 1%, treated with ultrasound-guided compression or thrombin injection.
- Retroperitoneal haematoma (Retroperitoneal haematoma) — the risk of its development is associated with puncture above the inguinal ligament in antegrade access.
- Rare complications — arterial dissection, perforation, thrombosis, and distal embolisation, the frequency of which in diagnostic angiography is less than 0.1%.
What are the anatomical landmarks for locating the common femoral artery on ultrasound?
The main anatomical landmarks for locating the common femoral artery on ultrasound are the inguinal ligament and the adjacent vein.
- Inguinal ligament (Ligamentum inguinale) — the anatomical landmark at the level of which the external iliac artery transitions into the common femoral artery.
- Common femoral vein (Vena femoralis communis) — located in close proximity (next) to the target artery.
Additionally, ultrasound guidance allows differentiation between the superficial femoral artery (a. femoralis superficialis) and the profunda femoris artery (a. profunda femoris), ensuring precise guidewire passage and avoiding its unintentional entry into the deep branch.
What types of arterial access closure devices exist?
The sources do not provide a detailed classification of all types of devices, but mention a specific category and example. The following are used for arterial access closure:
- Closure devices (closure-device) — the Angio-Seal system is given as an example, which may be used off-label.
The use of arterial closure devices reliably reduces the risk of complications and is a safe alternative for direct superficial femoral artery puncture in obese patients.
Where is the inguinal ligament located and what is its significance during puncture?
The inguinal ligament (Ligamentum inguinale) is an anatomical landmark at the level of which the external iliac artery transitions into the common femoral artery. Its significance during puncture lies in defining the arterial access zone:
- Risk of complications — puncture above the inguinal ligament carries the risk of developing a retroperitoneal haematoma.
- Access selection — puncture above the inguinal ligament is often considered a contraindication to performing an antegrade puncture.
The iliopectinaceous arch (arcus iliopectineus) extends from the inguinal ligament to the iliopectineal eminence and divides the muscular and vascular lacunae.
Class and exam questions
Why should a hydrophilic guidewire not be used with a Seldinger needle?
Hydrophilic guidewires must not be used with beveled Seldinger needles due to the high risk of shearing the smooth coating of the guidewire against the sharp edge of the needle bevel.
What is the main danger of antegrade puncture above the inguinal ligament?
Arterial puncture above the level of the inguinal ligament carries a high risk of developing a retroperitoneal haematoma. This complication is often considered a contraindication to antegrade access.
Which arterial wall puncture technique is considered optimal?
The single-wall (anterior wall) puncture technique under continuous ultrasound guidance is considered the gold standard in interventional radiology.
How should the Seldinger needle be oriented when performing access?
An important technical rule dictates that the bevel of the needle tip during each puncture must be oriented strictly anteriorly.
What else to study on this topic
- Patient safety checklist algorithm
- Vascular closure devices
- Technique for catheter advancement across the aortic bifurcation (cross-over)
- Detailed ultrasound anatomy of the femoral triangle vessels
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