A 61-year-old man presented to his primary care physician complaining of worsening intermittent claudication of the right hip, buttock, and calf while trying to walk half a block. Upon further questioning the patient also admitted waking up in the middle of the night because of throbbing pain in his right toes. Significant findings on physical examination were absence of femoral and distal pulses of the right lower extremity. He also had evidence of muscle atrophy of the right calf. The left lower extremity had a normal palpable femoral pulse.
Ankle-brachial indices (ABIs) confirmed the presence of severe ischemia of right lower extremity with index of 0.4. Computed tomographic arteriogram (CTA) confirmed occlusion of the right common iliac and the right external iliac artery (Figure 7-1).
Computed tomographic (CT) angiogram illustrating occlusion of the right iliac system indicated by the red bracket.
This patient was seen by a vascular surgeon and because of severe claudication and developing rest pain, an extra-anatomic femoral—femoral artery bypass surgery was recommended.
He underwent uneventful left to right femorofemoral bypass surgery, during which blood flow from his left iliac artery was redirected to the right lower extremity (Figure 7-2).
Left to right femorofemoral bypass (arrow) redirecting the blood flow from the left iliac system to the right lower extremity.
Aortofemoral bypass remains the standard against which all extra-anatomic bypass surgeries' methods of reconstruction for distal aortic occlusion and iliac artery occlusion must be measured.1
The term extra-anatomic bypass applies to any bypass graft that is placed in a site different from that of the native arterial segment being bypassed. While many common vascular procedures such as femorotibial bypass might be considered extra-anatomic, this term specifically describes procedures addressing diseases of the aortoiliac and femoral arteries.1
Common extra-anatomic bypasses include axillofemoral and femorofemoral bypasses. Less common and more complex bypasses include obturator, thoracofemoral, and supraceliac-to-iliofemoral bypasses.
Historically, extra-anatomic procedures were developed to treat high-risk patients with severe medical comorbidities or with "hostile" abdomens. "Hostile" abdomen refers to patients with prior multiple abdominal operations that result in adhesions ("frozen" abdomen) or patients with active intra-abdominal infections (including "mycotic" aortic aneurysms, infected aortic prostheses, aortoenteric fistulae). "Hostile" groin refers to patients with infected femoral artery aneurysm, prosthetic graft groin infection, history of groin radiation, and malignancies involving the groin or femoral vessels.
Extra-anatomic bypasses require a long, subcutaneously placed prosthetic graft. These grafts are often externally supported with a removable continuous-spiral coil to reduce kinking and compression. Commonly used grafts are ePTFE and Dacron grafts.1
INDICATIONS FOR INTERVENTION
Two primary indications for extra-anatomic bypass ...