Carsten C G, Taylor S M, Langan E M, Crane M M
Department of Surgical Education, Greenville Hospital System, South Carolina 29605, USA.
Am Surg. 1998 Jan;64(1):33-7; discussion 37-8.
Lower-extremity limb salvage should parallel infrainguinal bypass graft patency. To determine factors associated with limb loss despite a patent bypass, we reviewed 191 consecutive infrainguinal bypasses in 158 patients followed prospectively over 42 months. In this series of 176 (92%) vein grafts, 15 (8%) expanded polytetrafluoroethylene grafts, 122 (64%) tibial artery bypasses, and 170 (89%) bypasses placed for limb salvage, 29 major lower-extremity (above-knee or below-knee) amputations were performed in 29 patients, 12 because of ischemia after graft thrombosis and 17 (9% of series) due to progression of soft tissue infection/necrosis despite a functioning bypass. Primary and secondary 36-month vein graft patencies by life-table analysis were 61 per cent and 81 per cent, respectively. When the 17 cases of limb loss were compared to the rest of the series, nonstatistically significant variables included male sex [11 (65%) vs 79 (56%); P = 0.608] and diabetes [12 (71%) vs 80 (57%); P = 0.310]. Statistically significant variables included black race [9 (53%) vs 39 (28%); P = 0.048]; chronic renal failure [6 (35%) vs 12 (9%); P = 0.005], placement to a tibial/pedal artery [15 (88%) vs 107 (62%); P = 0.034], distal anastomosis to the anterior tibial/dorsalis pedis (AT/DP) artery [8 (47%) vs 27 (16%); P = 0.004], and grafts requiring late revision [7 (41%) vs 22 (13%); P = 0.006]. Thirteen (76%) extremities had an intact pedal arch. Nine amputations were performed within 30 days (early group), and eight were performed from 45 days to 20 months (median, 8 months) after bypass placement (late group). The most common primary causes of limb loss in the early group were overwhelming progression of soft-tissue infection despite patent bypass (n = 4; 44%) and insufficient runoff in the foot (n = 3; 33%). In the late group, amputation most often followed long treatment of a chronic proximal diabetic neuropathic foot ulcer with osteomyelitis. Five (63%) grafts in this group were anastomosed to the AT/DP arteries. These data suggest that patients with chronic renal failure, chronic neuropathic heel ulcers, and an AT/DP bypass are at greater risk for amputation despite a working bypass, especially if the graft develops a hemodynamically significant stenosis. Careful judgment and patient selection under these circumstances are thus justified.
下肢肢体挽救应与腹股沟下旁路移植血管通畅情况相平行。为了确定尽管旁路移植血管通畅但仍导致肢体丧失的相关因素，我们回顾了158例患者连续进行的191例腹股沟下旁路移植手术，这些患者接受了为期42个月的前瞻性随访。在这一系列手术中，有176例（92%）采用静脉移植物，15例（8%）采用膨化聚四氟乙烯移植物，122例（64%）为胫动脉旁路移植，170例（89%）的旁路移植是为了挽救肢体。29例患者进行了29次主要的下肢（膝上或膝下）截肢手术，12例是由于移植血管血栓形成后的缺血，17例（占该系列的9%）是由于尽管旁路移植血管功能正常，但软组织感染/坏死仍进展所致。通过寿命表分析，静脉移植物36个月的一期和二期通畅率分别为61%和81%。将17例肢体丧失病例与该系列的其他病例进行比较时，无统计学意义的变量包括男性[11例（65%）对79例（56%）；P = 0.608]和糖尿病[12例（71%）对80例（57%）；P = 0.310]。有统计学意义的变量包括黑人种族[9例（53%）对39例（28%）；P = 0.048]；慢性肾衰竭[6例（35%）对12例（9%）；P = 0.005]，移植到胫/足部动脉[15例（88%）对107例（62%）；P = 0.034]，远端吻合至胫前/足背（AT/DP）动脉[8例（47%）对27例（16%）；P = 0.004]，以及需要后期翻修的移植物[7例（41%）对22例（13%）；P = 0.006]。13例（76%）肢体的足弓完整。9例截肢在30天内进行（早期组），8例在旁路移植术后45天至20个月（中位数为8个月）进行（晚期组）。早期组肢体丧失最常见的主要原因是尽管旁路移植血管通畅，但软组织感染仍急剧进展（n = 4；44%）以及足部血流灌注不足（n = 3；33%）。在晚期组，截肢最常发生在对慢性近端糖尿病神经性足部溃疡合并骨髓炎进行长期治疗之后。该组中有5例（63%）移植物吻合至AT/DP动脉。这些数据表明，患有慢性肾衰竭、慢性神经性足跟溃疡且进行了AT/DP旁路移植的患者，尽管旁路移植血管功能正常，但截肢风险更高，尤其是当移植物出现血流动力学上有显著意义的狭窄时。因此，在这些情况下进行仔细的判断和患者选择是合理的。
