University of Massachusetts Medical Center, Worcester, Mass.
J Vasc Surg. 2013 Oct;58(4):949-56. doi: 10.1016/j.jvs.2013.04.036. Epub 2013 May 25.
Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia.
All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year.
Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation, deterioration in renal function, and respiratory complications. Patients who underwent lower extremity bypass for acute limb ischemia had no difference in rates of graft occlusion (18.1% vs 18.5%; P = .77), but did have significantly higher rates of limb loss (22.4% vs 9.7%; P < .0001) and mortality (20.9% vs 13.1%; P < .0001) at 1 year. On multivariable analysis, acute limb ischemia was an independent predictor of both major amputation (hazard ratio, 2.16; confidence interval, 1.38-3.40; P = .001) and mortality (hazard ratio, 1.41; confidence interval, 1.09-1.83; P = .009) at 1 year.
Patients who present with acute limb ischemia represent a less medically optimized subgroup within the population of patients undergoing lower extremity bypass. These patients may be expected to have more complex operations followed by increased rates of perioperative adverse events. Additionally, despite equivalent graft patency rates, patients undergoing lower extremity bypass for acute ischemia have significantly higher rates of major amputation and mortality at 1 year.
急性肢体缺血仍然是血管外科最具挑战性的急症之一。历史上，急性肢体缺血干预后的结果与高发病率和死亡率相关。本研究的目的是确定下肢旁路手术后急性肢体缺血的当代结果。
在新英格兰血管研究组的医院中，确定了 2003 年至 2011 年期间进行的下肢下肢旁路手术的所有患者。根据下肢旁路的适应证是否为急性肢体缺血，将患者分层。主要终点包括 1 年后旁路移植物闭塞、大截肢和死亡率，通过 Kaplan-Meier 生存表分析确定。构建多变量 Cox 比例风险模型，以评估 1 年后死亡率和大截肢的独立预测因素。
在 5712 例下肢旁路手术中，323 例（5.7%）为急性肢体缺血。与慢性肢体缺血患者相比，行下肢旁路治疗急性肢体缺血的患者在年龄（66 岁与 67 岁；P =.084）和性别（68%男性与 69%男性；P =.617）方面相似，但更不可能服用阿司匹林（63%与 75%；P <.0001）或他汀类药物（55%与 68%；P <.0001）。急性肢体缺血患者更可能是当前吸烟者（49%与 39%；P <.0001），更可能有同侧旁路手术史（33%与 24%；P =.004）或同侧经皮介入治疗史（41%与 29%；P =.001）。急性肢体缺血患者的手术时间更长（270 分钟与 244 分钟；P =.007），失血量更多（363 毫升与 272 毫升；P <.0001），更常使用人工移植物（41%与 33%；P =.003）。急性肢体缺血患者的院内主要不良事件发生率更高（20%与 12%；P <.0001），包括心肌梗死、充血性心力衰竭恶化、肾功能恶化和呼吸并发症。接受下肢旁路治疗急性肢体缺血的患者在移植物闭塞率方面没有差异（18.1%与 18.5%；P =.77），但肢体丧失率（22.4%与 9.7%；P <.0001）和死亡率（20.9%与 13.1%；P <.0001）在 1 年内明显更高。多变量分析显示，急性肢体缺血是 1 年内大截肢（危险比，2.16；置信区间，1.38-3.40；P =.001）和死亡率（危险比，1.41；置信区间，1.09-1.83；P =.009）的独立预测因素。
出现急性肢体缺血的患者在接受下肢旁路手术的患者群体中代表了一个医疗优化程度较低的亚组。这些患者可能需要进行更复杂的手术，随后围手术期不良事件的发生率也会增加。此外，尽管旁路移植物通畅率相当，但接受急性肢体缺血下肢旁路手术的患者在 1 年内的大截肢和死亡率明显更高。
