Extraanatomic Repair of Aortoiliac Occlusive Disease

Historical Background

Extraanatomic procedures were developed as alternatives to direct aortofemoral bypass for patients deemed to be at high risk for direct aortic surgery or for those presenting with a “hostile” abdomen, an infection of the native aortoiliac arterial system, or prior prosthetic replacement of the aortoiliac system. The first extraanatomic procedure to be described for treatment of aortoiliac occlusive disease was the femoral-femoral bypass, which was first reported by Freeman in 1952. In 1962 Vetto provided the first comprehensive description of a significant number of cases with an analysis of clinical outcomes. Axillofemoral bypass was first reported by Blaisdell and Louw in 1963, and by 1968 growing experience supported this option as a safe alternative to direct aortic reconstruction. The feasability of thoracofemoral bypass was first reported in 1961, but it was not until the 1980s and 1990s that retrospective reviews reported long-term outcomes for patients treated with this approach. Balloon thromboembolectomy was introduced by Fogarty and colleagues in 1963, with reports of its utility for treatment of aortoiliac embolism appearing soon thereafter.

Preoperative Preparation

• Prophylactic antibiotics. Extraanatomic bypass is nearly always performed with prosthetic material, either expanded polytetrafluoroethylene (ePTFE) or polyester. Infection of these grafts is associated with a high risk of loss of life or limb. Thus preexisting infection should be treated to the extent possible before placing the grafts, and antibiotics administered to reduce the risk of secondary graft infection.

• Risk assessment. Cardiac, pulmonary, and renal function should be assessed and optimized.

• Emergent or urgent intervention. Arterial embolectomy is implicitly an urgent or emergent procedure in most cases, so preoperative care is usually limited to volume resuscitation, transfusion, and other measures to optimize organ function. Mortality related to arterial embolectomy remains high, due to advanced age and associated comorbidities, particularly cardiac disease.

Pitfalls and Danger Points

• Injury to the axillary and subclavian arteries, veins, and brachial plexus. The axillosubclavian artery is characteristically less robust than the femoral artery, and injury from dissection, clamp placement, or sutures tearing through the artery is more likely. Injury could conceivably require transection of the clavicle, sternotomy, or thoracotomy to facilitate repair. The axillary artery and vein and brachial plexus may also be injured during tunneling of the axillofemoral graft.

• Disruption of the axillary artery anastomosis. The axillary artery anastomosis should be placed as medial (adjacent to the clavicle) as possible and to allow some redundancy in the axillary end of the axillofemoral graft. This will minimize the risk of “axillary pullout,” or disruption of the axillary anastomosis with arm abduction. The axillofemoral graft should also be placed in the midaxillary line to reduce the risk of kinking during torso flexion.

• Bladder or bowel injury. Bladder or bowel injury is possible when tunneling a femoral-femoral graft if the graft is placed in the retrofascial space or if the patient has a suprapubic hernia, particularly if there has been previous surgery in this area.

• Iatrogenic injury during embolectomy. Embolectomy leads to arterial perforation, rupture, and dissection. The catheter should not be “forced” when advancing it, (i.e., if the catheter meets with resistance, it should be withdrawn a significant distance and then readvanced and rotated somewhat to try to “give a different look” to the catheter tip). The surgeon must learn to get tactile information from both hands, (i.e., a sense of resistance when advancing the catheter and drag on the catheter when withdrawing with the balloon inflated), and a sense of the resistance to inflation using the syringe. Pulling back on an overinflated balloon can do irreparable damage in the short term and produces significant vasospasm, particularly in the infrapopliteal arteries.

Femoral-Femoral Bypass

Incision and Exposure

Femoral-femoral bypass depends on the ability of one “donor” iliac artery to supply enough blood flow to perfuse both the donor and the “recipient” legs ( Fig. 29-1 ). Oblique, groin-crease incisions may be used, but longitudinal groin incisions centered over the femoral arteries and beginning approximately at the inguinal ligament provide the most flexibility and are preferred by most surgeons. Incision length depends on patient habitus. Anastomoses to the common femoral artery may extend onto the deep or superficial femoral artery and may occasionally be made directly to the deep or superficial femoral arteries. This decision is most often made after exposure, inspection, and palpation of the femoral arteries, but it is also predicted by complete preoperative imaging. The extent of dissection to control femoral arteries and the use of vascular clamps, silicone elastomer (Silastic) vessel loops, or occasionally balloon catheters are dictated by the site of anastomosis, surgeon preference, and whether there has been previous surgical exposure of the femoral arteries.