The "blue-toe" syndrome as a harbinger of impending infrainguinal vein graft failure: a report of three cases.

Spontaneous "blue-toe" syndrome classically results from distal lower extremity microembolization of intraluminal atheromatous debris from a proximal source to the digital end arteries. During a 6-year period, 274 consecutive infrainguinal reversed vein arterial reconstructions were performed; in three patients (1.1% incidence), atypical distal microembolization originating from focal preocclusive intraluminal vein graft stenoses was identified. Sudden, spontaneous onset of ipsilateral blue-toe syndrome occurred at intervals of 4 to 11 months. Subsequent duplex scans and arteriography demonstrated patent grafts with high-grade, hemodynamically significant focal proximal short-segment sclerotic vein graft stenosis (n = 1) and midgraft valvular weblike stenoses (n = 2) with luminal irregularity. No other associated tandem lesions in the proximal or distal arterial tree were noted that would account for the microembolic phenomenon. The stenotic vein segments were excised with interposition vein graft replacement (n = 1) or with primary end-to-end reanastomoses (n = 2), resulting in complete resolution of the distal microembolic events without need for amputation. Histologic examination of these graft lesions demonstrated significant focal myointimal hyperplasia with adherent platelet aggregates and organized thrombus. The clinical presentation of distal lower extremity cutaneous digital ischemia consistent with microembolization developing ipsilateral to a previously placed vein conduit arterial bypass may signify a "failing" graft with a source from a preocclusive lesion. This finding should prompt aggressive evaluation and immediate revision to maintain assisted primary graft patency and prevention of tissue loss.