Obturator Foramen Bypass Grafts in Groin Sepsis

Patient Selection

A fundamental prerequisite for a successful outcome of obturator bypass in the patient with arterial infection in the groin is that the septic process be truly confined to the groin. This approach is most appropriate for the patient with native femoral artery infection. Although rarely a patient has an infected arteriosclerotic femoral artery aneurysm or septic arteritis resulting from previous vascular cannulation for a diagnostic arteriogram or an endovascular procedure, a more common scenario is the presence of a mycotic pseudoaneurysm in an illicit drug user.

Obturator foramen bypass is also a viable option in the patient with infection involving a previously placed prosthetic bypass graft. For example, it is an excellent procedure for providing inflow to the recipient limb in the patient who requires excision of an infected femorofemoral bypass graft. In this situation the native iliac artery (ipsilateral or contralateral) or aorta should be uninvolved with the infectious process. On the other hand, one must be cautious in planning an obturator bypass in the patient with infection involving the patent limb of an aortofemoral bypass because infection occurring in the groin in this situation often tracks proximally along the entire extent of that graft limb, and in fact the main body of the graft may be involved. In this situation the proximal extent of the septic process precludes performing the proximal anastomosis of the new graft in a clean field. Similarly, when the patient has an infection involving the proximal segment of an infrainguinal bypass graft in the groin, it is important to rule out extension of the septic process along the more distal aspect of the conduit so that one can perform the distal anastomosis of the obturator bypass at an infection-free site.

The acuteness of the clinical presentation influences the completeness of the preoperative workup. In the stable patient with graft infection in the groin, the author obtains a computed tomography (CT) scan to assess proximal or distal extension of the septic process. The presence of perigraft gas or fluid and loss of the perigraft fat signal are presumptive evidence of infection. Alternatively, magnetic resonance imaging (MRI) can provide similar evidence of perigraft infection. The CT or MRI should be followed by arteriography both to identify any unsuspected anastomotic aneurysms proximal or distal to the groin and to assess the infrainguinal vascular anatomy to select the most appropriate site for the distal anastomosis of the obturator foramen bypass graft.