Resource utilization in the treatment of critical limb ischemia: the effect of tissue loss, comorbidities, and graft-related events

Objective

Resource utilization (RU) in the care of patients with critical limb ischemia (CLI) is not well quantified. We present a cohort study to quantify in-hospital RU and analyze the role of tissue loss (TL), comorbidities, and vascular graft-related events (GREs) in patients undergoing peripheral bypass for CLI.

Methods

A retrospective analysis of 1404 patients enrolled in a multicenter clinical trial (PREVENT III) of vein bypass grafting for CLI was performed with analysis of RU during the 1-year follow-up period. Univariate and multivariable linear regressions were performed to determine RU predictors and outcomes.

Results

Compared with patients with rest pain, patients presenting with TL as the indication for bypass surgery had a longer index length of stay (mean, 9.8 vs 6.2 days), more rehospitalizations (mean, 1.6 vs 1.2), and a longer cumulative length of stay (mean, 27.7 vs 17.3 days; P < .0001 for all comparisons). Rehospitalizations over the ensuing year were for additional procedures (37.5%), wound infection (14.6%), graft failure (10.7%), and other cardiovascular (10%) and noncardiovascular (26%) reasons. Early GRE (stenosis ≥70%, thrombosis, revision, or major amputation within 30 days) occurred in 162 (11.5%) patients, resulting in a longer index length of stay (mean, 11.8 vs 8.6 days; P = .0002) and cumulative length of stay (mean, 25.9 vs 24.6 days; P = .0043), but no difference in the number of rehospitalizations (mean, 1.6 vs 1.5 days; P = .3272). During the 1-year follow-up, 554 (39.5%) patients had GREs, and this resulted in more rehospitalizations (mean, 2.1 vs 1.1; P < .0001) and a longer cumulative length of stay (mean, 28.2 vs 21.9 days; P < .0001) compared with patients without GRE. Multivariable analysis demonstrated the highly positive association of TL (hazard ratio [HR], 1.75) and early GRE (HR, 1.77) with the index length of stay, whereas comorbidities—namely, dialysis dependency (HR, 1.31), nonsmoking status (HR, 1.29), hypertension (HR, 1.26), and increasing age (HR, 1.01)—also had strong effects. The effect of TL and GRE on later RU (number of rehospitalizations and cumulative length of stay) was present but less pronounced than patient comorbidities (namely, dialysis).

Conclusions

The stage of disease at presentation (TL vs rest pain) and the patency of the bypass graft (freedom from GRE) are critical determinants of RU over the first year after limb-salvage surgery. These effects predominate early (index length of stay) and persist through 1 year. Patient-specific factors, particularly dialysis-dependent renal failure, are also critical comorbidities affecting RU in these patients.