Preoperative functional status predicts perioperative outcomes after infrainguinal bypass surgery.

OBJECTIVE

Infrainguinal surgical bypass (BPG) is a durable method for lower extremity revascularization, but is accompanied by significant 30-day morbidity and mortality (MM). The goal of this study is to relate preoperative functional status, a defined metric in the National Surgical Quality Improvement Program (NSQIP) database, to perioperative MM.

METHODS

Between January 1, 2005 and December 31, 2007, all patients who underwent BPG from the NSQIP private sector database were reviewed. The primary end-point was 30-day MM. Patients were stratified by preoperative functional status: independent (IND) vs dependent (DEP). Associated patient demographic/clinical data were analyzed using univariate and multivariate methods. Composite odds ratios were constructed with clusters of high-risk comorbidities.

RESULTS

There were 5639 BPG patients (4600 [81.6%] IND and 1039 [18.4%]) DEP. DEP patients were significantly older (71.6 +/- 11.8 vs 66.8 +/- 11.8 years; P < .0001), had more chronic obstructive pulmonary disease (COPD) (16.7% vs 11.4%; P < .0001), diabetes (54.2% vs 40.7%; P < .0001), dialysis dependence (16.4% vs 5.6%; P < .0001), and critical limb ischemia (64.6% vs 44.0%; P < .0001). DEP patients had a higher incidence of death (6.1% vs 1.5%; P < .0001) and major complications (30.3% vs 14.2%; P < .0001). DEP was an independent predictor of major complications (odds ratio [OR]: 2.0; 95% confidence interval [CI]: [1.7-2.4]; P < .0001) major systemic complications (2.5 [1.9-3.2]; P < .0001), major operative site complications (1.6 [1.4-1.9]; P < .0001) and death (2.3[1.6-3.4]; P < .0001). The combination of DEP with emergency surgery, Cr > 1.8, or rest pain increased the odds of major complications by five, seven, or 11-fold, respectively. The combination of DEP with hemodialysis, emergency surgery, or age > or = 80 years increased the odds of death by 13, 38, or 87-fold, respectively.

CONCLUSION

Preoperative DEP is significantly correlated with all adverse 30-day outcomes in BPG patients. Furthermore, when combined in high-risk composites with specific preoperative clinical variables, DEP is associated with prohibitive MM, thereby identifying patient cohorts that may be unsuitable for BPG.