Clinical success using patient-oriented outcome measures after lower extremity bypass and endovascular intervention for ischemic tissue loss.

INTRODUCTION: Successful outcome after lower extremity revascularization is usually measured by physician-oriented terms such as graft patency and amputation-free survival. It has been increasingly appreciated that these criteria do not necessarily translate into success from the prospective of the patient. The purpose of this study, therefore, is to retrospectively examine success after lower extremity revascularization for tissue loss using patient-oriented measures and to include patients who underwent both open surgical bypass and endovascular therapy.
METHODS: Between 1998 and 2005, 677 patients (316 endovascular and 361 open surgery) underwent revascularization for ischemic tissue loss. The method of revascularization (endovascular or open surgery) was left to the discretion of the surgeon. Revascularization was considered to be clinically successful if each of the following occurred: reconstruction patency until wound healing, limb salvage for 1 year, maintenance of ambulation for 1 year, and survival for 6 months. The influence of 20 intrinsic patient factors, including type of revascularization (open vs endo) was examined using the chi(2) test. Significant factors in bivariate analysis were included in a logistic regression model to determine independent predictors and probability of failure.
RESULTS: Overall clinical success was achieved in 277 (40.9%) patients. Success for open surgical and endovascular cohorts was 44.3% and 37.0%, respectively (P = .06). Type of intervention was not a significant factor in either bivariate or logistic regression analysis. Independent predictors of failure (odds ratio [OR]; 95% confidence interval [CI]) regardless of treatment type included impaired ambulatory status at the time of presentation (OR 3.24; CI 2.14, 4.90), diabetes (OR 1.62; CI 1.14, 2.32), endstage renal disease (ESRD) (OR 1.55; CI 1.07, 2.23), presence of gangrene (OR 2.0; CI 1.42, 2.82), and prior vascular intervention (OR 1.46; CI 1.02, 2.10). Paradoxically, hyperlipidemia (OR 0.70; CI 0.50, 0.98) was a predictor for success. Probability of failure was 35.4% (OR 1.0) if no independent predictors were present and increased with the addition of each adverse predictor. For instance, diabetic patients with impaired ambulatory status and gangrene had an 85.2% (OR 10.5) probability of failure. In the worst case scenario, a diabetic patient with ESRD, impaired ambulatory status, gangrene, and a prior vascular intervention was considered, probability of failure was a dismal 92.8% (OR 23.7).
CONCLUSION: Clinical success after lower extremity revascularization for ischemic tissue loss is determined by intrinsic patient factors and not by method of revascularization. These data reiterate that future investigation efforts should be focused less on the method of revascularization and more on identification of patient cohorts at risk for failure regardless of treatment.