Advantages of the Retrograde Approach in Treating Proximal Occlusive Disease

Hello and welcome to the August 2018 edition of Vascular Disease Management. I have chosen to comment on Dr Barik and colleagues’ case report on the utilization of popliteal artery access to successfully treat a totally occluded right common and external iliac artery, as well as a totally occluded right common femoral artery in a patient presenting with critical limb ischemia.

Retrograde popliteal artery access to facilitate crossing and treatment of upstream arterial occlusions was first reported by Dr Samuel Stagg in Vascular and Endovascular Surgery¹ in January of 1991. Since that time, the retrograde approach to facilitate crossing and treatment of totally occluded peripheral arteries has expanded to the transcollateral approach, direct mid or distal superficial femoral artery (SFA) access, pedal arterial access, and even digital arterial access within the foot. The retrograde approach has many advantages in treating proximal occlusive disease. When arterial occlusions occur, the vessel typically clots back to a proximal side branch.

In long total occlusions, this may result in an ambiguous proximal cap of the total occlusion as demonstrated in Dr Barik’s case. Lesions with ambiguous proximal caps may be successfully crossed in antegrade fashion, but in many cases the crossing devices (typically wires) simply deflect into the side branches or into a direct subintimal or even extravascular course. Retrograde approach allows operators to approach a more favorable distal occlusive cap (where there is often better geometry and less chance of the crossing device slipping into a collateral vessel).

Retrograde approach (particularly popliteal and distal SFA access) facilitates better wire torque and penetration, as it allows a more inline approach to an arterial occlusion and is much closer to the site of intended treatment. The proximity to the occlusion and the direct vector forces result in far greater pushability and deliverability of treatment tools (important in densely calcified lesions). In cases of distal popliteal access, the patient may need to be positioned in a prone manner, but distal SFA and P1 segment popliteal access can be performed with the patient supine with the leg placed in a “frog-like” position. Popliteal artery access allows operators to avoid puncture within areas of extensive scar or active infection.

Popliteal access can be guided by angiographic imaging or by external ultrasound. Ultrasound-guided access can limit the risk of inadvertent puncture of the popliteal vein, which may result in arteriovenous fistula. This is most important when accessing the more distal popliteal artery, where the vein is directly posterior to the artery.

It is crucial that the site of access allows sheath placement without resultant vessel occlusion. Reported complications of popliteal artery access include bleeding, thrombosis (typically with occlusive sheaths or inadequate anticoagulation), and arteriovenous fistulae. As compared with pedal access, popliteal and distal SFA access allows utilization of larger sheaths and is associated with better torque and pushability of wires and devices. Retrograde popliteal access does not allow treatment of the distal popliteal or infrapopliteal lesions and has more bleeding complications.

As with any form of access, operators must frequently flush sheaths, maintain adequate anticoagulation, and remove the sheath if there is difficulty in aspirating blood to avoid iatrogenic embolization of thrombus as demonstrated in this case.

Appropriate vascular access is crucial in achieving successful interventional outcomes. Access affects ability to cross lesions, ability to deliver devices, and the risk of access-site complications. Peripheral interventionists must be facile with obtaining and managing alternate arterial access sites.

REFERENCE

1. Stagg SJ, Chaisson G, Ladd WR,Walker CM.The popliteal approach: a new approach to percutaneous laser-assisted angioplasty. Vasc Endovasc Surg. 1991;25:23-28.