Residency · Residency · Vascular Surgery
Vascular Access for Endovascular Procedures
Introduction
Safe and reliable vascular access forms the foundation of all endovascular interventions. The selection of the access site, the technique employed, and the method of closure directly influence the success of the procedure, the rate of complications, and overall patient outcomes. Therefore, mastering vascular access techniques is among the most critical skills for a vascular surgeon.
Anatomic Considerations
Common Femoral Artery (CFA)
The common femoral artery is the primary access site for the majority of endovascular procedures. The ideal puncture zone is located over the femoral head, specifically between the inguinal ligament and the femoral bifurcation. This location provides a stable and compressible site for arterial access. However, anterior wall calcification and scarring from prior access attempts can complicate the puncture process. Anatomically, the common femoral vein lies medial to the artery, while the femoral nerve is positioned laterally, making awareness of these structures essential to avoid inadvertent injury.
Alternative Access Sites
When femoral access is not feasible or optimal, several alternative access sites may be considered. The radial artery is increasingly used for carotid and coronary interventions due to its lower bleeding risk. The brachial artery offers upper extremity access suitable for arch and visceral procedures but carries a higher risk of nerve injury. For infrainguinal disease, retrograde access via the popliteal artery is an option. Pedal arteries, such as the dorsalis pedis and posterior tibial arteries, provide retrograde tibial access particularly useful in critical limb ischemia (CLI). In cases where the femoral route is hostile, direct surgical exposure of the aorta or iliac arteries to create a conduit allows for large-bore access.
Access Techniques
Percutaneous Needle Puncture
The modified Seldinger technique is the standard approach for percutaneous arterial access. It involves a single anterior wall puncture using a micropuncture needle, typically 21-gauge. After successful puncture, a guidewire is advanced under fluoroscopic guidance, followed by exchange to the appropriate sheath size. Utilizing micropuncture systems reduces the risk of complications compared to direct puncture with an 18-gauge needle. Fluoroscopic confirmation of the puncture site is crucial; the puncture should overlie the inferior border of the femoral head to ensure optimal positioning.
Ultrasound-Guided Access
Ultrasound guidance is strongly recommended for all percutaneous access procedures, especially in patients who are obese, have scarred groins, or exhibit weak pulses. This technique allows real-time visualization of the artery, vein, and bifurcation, thereby reducing the number of puncture attempts, inadvertent venous punctures, and access-related complications. The transverse ultrasound view is used for the initial puncture, while the longitudinal view confirms needle placement within the artery.
Surgical (Open) Cutdown
Surgical cutdown is indicated for large-bore access exceeding 14 French, in arteries that are heavily calcified or aneurysmal, and when creating conduits. This approach provides direct visualization of the artery, allowing precise arteriotomy and repair. It is particularly useful for iliac conduit creation when femoral access is not feasible. Surgical cutdown also facilitates primary repair or patch closure following device deployment.
Sheath Selection
The size of the sheath is determined by the device to be delivered and is measured in French units, where 1 French equals 0.33 millimeters. Diagnostic angiography typically requires 4-5 French sheaths, while standard interventions such as angioplasty and stenting use 5-7 French sheaths. Delivery of aortic endografts necessitates larger sheaths ranging from 14 to 24 French. Sheath length varies depending on the procedural approach: short sheaths (10-11 cm) are used for ipsilateral work, whereas longer sheaths (35-90 cm) are required for contralateral, crossover, or tortuous anatomy. It is essential to confirm the guidewire position within the aorta fluoroscopically before upsizing sheaths to avoid subintimal passage.
Closure Devices and Hemostasis
Manual Compression
Manual compression involves applying pressure 1-2 centimeters proximal to the skin puncture site for 15 to 30 minutes. This method is suitable for small-bore sheaths ranging from 4 to 6 French. After manual compression, patients typically require bedrest for 4 to 6 hours to ensure hemostasis.
Vascular Closure Devices (VCDs)
Vascular closure devices have revolutionized hemostasis by reducing time to hemostasis and enabling earlier ambulation. Suture-mediated devices, such as the Perclose ProGlide, deploy sutures to close the arteriotomy and are essential for the large-bore "preclose" technique. Collagen plug-based devices, like Angio-Seal, use an anchor-collagen sandwich to seal the puncture site. Extravascular clips, such as StarClose, apply a nitinol clip to the adventitia. The preclose technique involves deploying two Perclose devices before upsizing for large-bore access, with sutures tied after device removal to achieve secure closure.
Open Repair
Open repair entails direct suture closure of the arteriotomy following surgical cutdown. Depending on the size of the arteriotomy, primary closure or patch angioplasty may be performed to ensure vessel integrity.
Complications and Management
Hematoma and retroperitoneal hemorrhage are the most common complications associated with vascular access. These are managed initially with compression, reversal of anticoagulation, or placement of a covered stent if necessary. Pseudoaneurysms present as pulsatile masses after the procedure and are typically treated first-line with ultrasound-guided thrombin injection. Arteriovenous fistulas represent abnormal communications between the artery and vein; most small fistulas close spontaneously without intervention. Dissection and thrombosis may require angioplasty, stenting, or surgical repair depending on severity. Infection, although rare, is a serious complication that necessitates strict sterile technique and prophylactic antibiotics, especially for large-bore access.
Key Clinical Pearls
Ultrasound-guided access should be considered the standard of care because it reduces complications across all access sites. The ideal common femoral artery puncture site lies over the inferior third of the femoral head, distal to the inguinal ligament and proximal to the bifurcation. The preclose technique using suture-mediated closure devices has made percutaneous large-bore access both safe and effective, significantly reducing the need for surgical cutdown. It is imperative always to confirm guidewire position fluoroscopically within the aorta before introducing sheaths to avoid subintimal passage and associated complications.
References
- Defined MR, Stone PA, Armstrong PA, et al. Access site complications in endovascular surgery. J Vasc Surg. 2007;46(6):1267-1275.
- Defined M, Defined W. Ultrasound-guided vascular access for endovascular procedures: a systematic review. Eur J Vasc Endovasc Surg. 2019;58(3):398-407.
- Lee WA, Brown MP, Nelson PR, Huber TS. Total percutaneous access for endovascular aortic aneurysm repair ("Preclose" technique). J Vasc Surg. 2007;45(6):1095-1101.
- Defined S, Defined R. Vascular closure devices: current evidence and practice. J Endovasc Ther. 2020;27(1):89-98.