Patency and limb salvage rates after distal revascularization to unclampable calcified outflow arteries

ABSTRACT. Purpose. Severe circumferential calcification of the outflow artery during lower extremity distal revascularization is considered a poor prognostic factor for bypass graft patency. The aim of this study was to assess the influence of circumferential infrapopliteal arterial calcification on bypass patency and limb salvage rates, comparing patency and limb salvage rates in unclampable calcified distal outflow arteries with those observed in uncalcified distal outflow arteries. Methods. From July 1990 to July 1997, out of 441 distal bypass procedures performed by the same surgeon, 69 (16%, group I) involved unclampable calcified outflow vessels while 83 (19%, group II) outflow vessels were uncalcified; the other 289 (65%) had varying intermediate degrees of calcification and were not included in this analysis. All procedures were performed for limb-threatening ischemia and involved standard vein patch angioplasty of the distal anastomotic site, irrespective of the conduit used. Primary and secondary patency, limb salvage and survival rates were assessed using Kaplan-Meier analysis. Results. Groups were similar with regard to age, sex and atherosclerotic risk factors except for a higher incidence of diabetes mellitus (88% vs 65%, P = .001) and renal failure (17% vs 5%, P = .01), including dialysis dependency (P = .01), in group I. Gangrene as an indication for surgery was statistically more frequent in group I (49% vs 29%, P = .01). The distal anastomotic locations and types of conduit involved were similar in the two groups. The femoral inflow level was used more often in group II (63% vs 38%, P = .003), the popliteal in group I (32% vs 17%, P = .03). Follow-up ranged from 30 days to 144 months, with a mean of 69 months. None of the patients were lost during follow-up period. None of the patients died during the perioperative (30-day) period. Primary patency rates at 1, 3 and 5 years were 84%, 65% and 52% for group I and 89%, 76% and 69% for group II (P = .07. ). Secondary patency rates at 1, 3 and 5 years were 96%, 82% and 78% for group I and 96%, 85% and 82% for group II (P = .58). Limb salvage rates at 1, 3 and 5 years were 93%, 83% and 81% for group I and 97%, 90% and 86% for group II (P = .39). Conclusions. Distal revascularization to unclampable, severely calcified outflow arteries can achieve much the same results to those obtained in uncalcified outflow arteries. A circumferentially calcified distal recipient artery should not be considered a major obstacle to an attempt at limb salvage bypass surgery.