Prior contralateral amputation predicts outcomes after LEB for critical limb ischemia

Researchers from the Vascular Study Group of New England (VSGNE) report that prior contralateral amputation predicts worse outcomes for lower extremity bypasses (LEB's) performed in the intact limb."This is the first study conducted that suggests contralateral amputation as a predictor of outcomes after LEB for critical limb ischemia (CLI)," said co-author Donald T. Baril, MD, assistant professor in the division of vascular and endovascular surgery at the University of Massachusetts Medical School in Worchester.

A retrospective analysis of all patients undergoing infrainguinal LEB for CLI between 2003 and 2010 within hospitals comprising the Vascular Study Group of New England was performed. Patients were stratified according to whether or not they had previously undergone a contralateral major or minor amputation before LEB. Primary end points included major amputation and graft occlusion at one year postoperatively. Secondary end points included in-hospital major adverse events, discharge status and mortality at one year.

Of 2,636 LEB procedures, 228 (8.6 percent) were performed in the setting of a prior contralateral amputation. Patients with a prior amputation compared to those without were more likely to have congestive heart failure (CHF) (25 percent vs. 16 percent), hypertension (94 percent vs. 85 percent), renal insufficiency (26 percent vs. 14 percent), and hemodialysis-dependent renal failure (14 percent vs. 6 percent). These patients were younger (66.5 vs. 68.7 percent), more likely to be nursing home residents (8 percent vs. 3.6 percent), less likely to ambulate without assistance (41 percent vs. 80 percent) and more likely to have had a prior ipsilateral bypass (20 percent vs. 12 percent).

Patients with prior amputation experienced increased in-hospital major adverse events, including myocardial infarction (8.9 percent vs. 4.2 percent), CHF (6.1 percent vs. 3.4 percent), deterioration in renal function (9.0 percent vs. 4.7 percent), and respiratory complications (4.2 percent vs. 2.3 percent). They were less likely to be discharged home (52 percent vs. 72 percent) or to be ambulatory on discharge (25 percent vs. 55 percent). Although patients with a prior contralateral amputation experienced increased rates of graft occlusion (38 percent vs.17 percent) and major amputation (16 percent vs. 7 percent) at one year, there was not a significant difference in mortality (16 percent vs. 10 percent).

On multivariable analysis, prior contralateral amputation was an independent predictor of both major amputation (odds ratio, 1.73; confidence interval, 1.06-2.83) and graft occlusion (odds ratio, 1.93; confidence interval, 1.39-2.68) at one year.

"Our study shows that patients with prior contralateral amputations who present with CLI in the intact limb represent a high-risk population with increased comorbidity rates compared to those without, even among patients with advanced peripheral arterial disease," said Dr. Baril. "Physicians and patients should expect increased rates of perioperative adverse events, increased rates of one-year graft occlusion and increased rates of limb loss when compared with patients who have not had a prior contralateral amputation. The presence of a prior contralateral amputation, along with other known predictors of LEB failure should be factored into the decision when selecting a treatment for lower extremity occlusive disease."