Sivamurthy Nayan, Schneider Darren B, Reilly Linda M, Rapp Joseph H, Skovobogatyy Herman, Chuter Timothy A M
Division of Vascular Surgery, University of California San Francisco Medical Center, 94143-0222, USA.
J Vasc Surg. 2006 Apr;43(4):662-70. doi: 10.1016/j.jvs.2005.11.044.
Endograft limb occlusion is an infrequent but serious complication of endovascular abdominal aortic aneurysm (AAA) repair. The insertion of additional stents within the endograft limb may prevent future occlusion. This study evaluates limb patency with and without adjunctive stenting of endograft limbs at the time of endovascular AAA repair.
We performed a retrospective review of 248 patients who underwent endovascular abdominal aortic aneurysm repair with the Zenith AAA endovascular graft between 1999 and 2004. Among these patients, two groups were identified: 64 patients with adjunctive stents placed in 85 limbs and 184 patients without additional bare stent placement in endograft limbs at the time of endovascular AAA repair.
Women comprised 23% of stented and 11% of unstented patients (P = .02). The mean length of follow-up in the stented and unstented groups was 2.0 years. There were 13 instances of limb thrombosis in 13 patients (5.2% of patients, 2.7% of limbs), all in the unstented group. No limb occlusions occurred in the presence of adjunctive bare metal stents. Seventy-three percent of the occlusions occurred < or = 6 months of endovascular AAA repair. Two patients (15%) had no symptoms of lower-extremity ischemia despite graft limb occlusion and did not undergo intervention. The others underwent thrombectomy (n = 2), thrombectomy with bare stent placement (n = 3), femoral-femoral bypass (n = 4), thrombolysis (n = 1), and thrombolysis with bare stent placement (n = 1). Of the seven who underwent thrombectomy or thrombolysis, three had no additional stents placed at the secondary procedure, and two of these three went on to rethrombose. By life-table analysis, primary patency at 3 years in the stented and nonstented limbs was 100% +/- 0% and 94% +/- 3%, respectively (P = .05).
The intraoperative insertion of additional bare metal stents appeared to eliminate the risk of thrombosis and was without complication. Of the 85 stented limbs in this series, not one occluded. The overall rate of limb thrombosis was low, with most limb occlusions occurring < or = 6 months of stent-graft insertion, and would probably have been even lower had we been able to identify all high-risk cases for prophylactic adjunctive stenting. Limb occlusion denotes an underlying problem with the graft, which if left untreated after thrombectomy or thrombolysis will lead to rethrombosis. Postoperative imaging was of little value in detecting impending limb occlusion. Based on these findings, we believe one should identify and stent any limbs that appear to be at risk for thrombosis, but this study lacks the data to predict which limbs need stenting.
腔内腹主动脉瘤（AAA）修复术后移植物肢体闭塞是一种少见但严重的并发症。在移植物肢体中插入额外的支架可能预防未来的闭塞。本研究评估腔内AAA修复时移植物肢体有无辅助支架置入情况下的肢体通畅情况。
我们对1999年至2004年间接受Zenith AAA腔内移植物进行腔内腹主动脉瘤修复的248例患者进行了回顾性研究。在这些患者中，确定了两组：64例患者在85个肢体中置入了辅助支架，184例患者在腔内AAA修复时未在移植物肢体中额外置入裸支架。
置入支架患者中女性占23%，未置入支架患者中女性占11%（P = 0.02）。置入支架组和未置入支架组的平均随访时间为2.0年。未置入支架组有13例患者发生13次肢体血栓形成（占患者的5.2%，占肢体的2.7%）。在有辅助裸金属支架的情况下未发生肢体闭塞。73%的闭塞发生在腔内AAA修复后≤6个月。2例患者（15%）尽管移植物肢体闭塞但无下肢缺血症状，未接受干预。其他患者接受了血栓切除术（n = 2）、血栓切除并置入裸支架（n = 3）、股-股旁路移植术（n = 4）、溶栓治疗（n = 1）以及溶栓并置入裸支架（n = 1）。在接受血栓切除术或溶栓治疗的7例患者中，3例在二次手术时未额外置入支架，这3例中有2例随后再次发生血栓形成。通过生命表分析，置入支架肢体和未置入支架肢体3年时的初始通畅率分别为100%±0%和94%±3%（P = 0.05）。
术中插入额外的裸金属支架似乎消除了血栓形成的风险且无并发症。在本系列的85个置入支架的肢体中，无一例闭塞。肢体血栓形成的总体发生率较低，大多数肢体闭塞发生在支架移植物置入后≤6个月，如果我们能够识别所有预防性辅助支架置入的高危病例，发生率可能会更低。肢体闭塞表明移植物存在潜在问题，血栓切除或溶栓后若不治疗将导致再次血栓形成。术后影像学检查在检测即将发生的肢体闭塞方面价值不大。基于这些发现，我们认为应该识别并对任何似乎有血栓形成风险的肢体置入支架，但本研究缺乏预测哪些肢体需要置入支架的数据。
