Descending Thoracic Aorta to Femoral Bypass

Indications

This operation is simple in concept but should be restricted to very special settings in which conventional arterial grafting configurations are inadequate. As a general rule, if simpler or more commonly used operations can achieve the same end, they should be used in preference to the thoracofemoral bypass. Thus, although the thoracic aorta provides excellent inflow for treatment of an infrarenal aortic occlusion, the routine intraabdominal approach remains preferred. Although the thoracofemoral operation has been described for situations of acute aortic infection, one might more reasonably use an axillofemoral bypass instead. The reason is that in the septic patient, if the extra-anatomic repair were to become infected, the axillary-based graft is easier to manage than one anastomosed to the descending thoracic aorta. Therefore, in the relatively common setting of infected infrarenal aortic bypass removal, an axillofemoral bypass is still recommended.

Three specific indications have evolved. The first indication is the rare situation of a hostile abdomen, usually after either extensive previous operations or radiation in the periaortic region. Circumstances including inflammatory bowel disease or abdominal wall deficiencies can enter into this decision. In such patients, aortic inflow from the left chest may be less traumatic than an abdominal exploration. The second indication is for repeated failure of abdominal aortic grafting. As a general rule, failure after a single aortofemoral bypass is appropriately managed with another intraabdominal aortic graft. After two failures, one may reasonably consider moving to the thoracic aorta for inflow. Finally, the thoracofemoral bypass has been useful for patients with multiple failed extra-anatomic bypasses. They include patients with axillopopliteal and axillofemoral grafts having had multiple graft thrombectomy operations. Many of these patients were first seen at the time of infected aortic graft removal, and reconstruction was performed in the usual way with axillary-based inflow grafts. Following removal of their infected grafts, many such patients enjoy a potentially long life and are gravely affected by their repeated axillary graft thromboses. A reconstruction providing an uninhibited inflow source such as the descending thoracic aorta and the intracavitary tunnel of the thoracofemoral bypass seems reasonable in this setting.