Distal revascularization and microvascular free tissue transfer: An alternative to amputation in ischemic lesions of the lower extremity

Abstract

Most lower extremity amputations result from complications of diabetes and arterio-sclerotic occlusive diseases below the inguinal ligament. Improved limb salvage has been achieved by an aggressive approach to distal revascularization in the severely ischemic lower extremity. There remains, however, a high incidence of amputation resulting from progression of the ulceration or gangrene into deeper and less well-vascularized tissues, such as tendon and bone. Even in the nonischemic extremity, such wounds rarely heal without flap coverage. Microvascular free tissue transfers promote healing by providing coverage with healthy, nondiseased, well-vascularized tissue for these difficult defects. Successful free flap transfer requires a high-pressure recipient inflow vessel. In contrast to individuals with nonarteriosclerotic lesions, many individuals with nonhealing ischemic lesions have no acceptable artery demonstrated on high-resolution angiography to serve as a recipient vessel. Limb salvage has been achieved in four candidates for amputation utilizing distal revascularization followed by free tissue transfer coverage of the ischemic lower leg defects.

Free flap ?steal? hastening amputation of a revascularized lower limb

“…Ever more distal revascularization procedures have led to improved limb salvage rates [8]. Despite such an aggressive approach to limb salvage, a high incidence of limb amputation still occurs due to an inability of these maneuvers alone to limit the progression of gangrene or tissue necrosis with resultant tendon or bone exposure [5]. This has been the impetus for attempting free tissue coverage of these more complex distal leg wounds [2][3][4]6].…”

“…A major obstacle due to this severe peripheral vascular disease has been a lack of satisfactory recipient vessels to serve as inflow conduits for the free tissue transfer. Prior or concurrent distal revascularization may not only then enhance distal limb circulation, but simultaneously provide this source of inflow for the free tissue transfer as well [5].…”

“…The microvascular transfer of flaps to replace soft tissue deficits as a sequela to underlying peripheral vascular disease has become an accepted adjunct to lower extremity revascularization in attempted limb salvage [1][2][3][4][5]. Success rates greater than 90% have been reported for such free tissue transfers [3,6].…”

“…Complications inherent with any free tissue transfer have been well described, with the most devastating being anastomotic thrombosis or disruption, which usually resulted in total flap failure [7]. However, ischemia of the recipient extremity itself due to a "steal syndrome" as a direct consequence of diversion of inflow by a successful free flap, although previously speculated as a theoretical but unlikely possibility [4][5][6], has not been specifically deCorrespondence to: G. G. Hallock, MD, 1230 South Cedar Crest Boulevard, Suite 306, Allentown, PA 18103, USA scribed as an outcome. Therefore, this case is unusual as it describes progressive critical lower extremity ischemia distal to a successful free flap that resulted in limb amputation.…”

Postoperative monitoring of free vascularized bone grafts in reconstruction of bone defects

“…Briggs et al, 25 who promoted this technique in the early-1980s, stated that a temperature between 30 and 328C was marginal, and a temperature below 308C was indicative for flap failure (see Fig. 1).…”