Impact of Hospital Caseload and Elective Admission on Outcomes After Extracranial-Intracranial Bypass Surgery

Background Limited information exists evaluating the impact of hospital caseload and elective admission on outcomes after patients have undergone extracranial-intracranial (ECIC) bypass surgery. Using the Nationwide Inpatient Sample (NIS) for 2001–2014, we evaluated the impact of hospital caseload and elective admission on outcomes after bypass. Methods In an observational cohort study, weighted estimates were used to investigate the association of hospital caseload and elective admission on short-term outcomes after bypass surgery using multivariable regression techniques. Results Overall, 10,679 patients (mean age, 43.39 ± 19.63 years; 59% female) underwent bypass across 495 nonfederal U.S. hospitals. In multivariable models, patients undergoing bypass at high-volume centers were associated with decreased probability of mortality (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.22–0.70; P < 0.001), length of stay (OR, 0.86; 95% CI, 0.82–0.90; P < 0.001), postbypass neurologic complications (OR, 0.66; 95% CI, 0.49–0.89; P = 0.007), venous thromboembolism (OR, 0.69; 95% CI, 0.49–0.97; P = 0.033), and acute renal failure (OR, 0.45; 95% CI, 0.26–0.80; P = 0.007), and higher hospitalization cost (26.3% higher) compared with low-volume centers. Likewise, patients undergoing elective bypass were associated with decreased likelihood of mortality (OR, 0.38; 95% CI, 0.25–0.59; P < 0.001), unfavorable discharge (OR, 0.57; 95% CI, 0.43–0.76; P < 0.001), length of stay (OR, 0.62; 95% CI, 0.59–0.64; P < 0.001), venous thromboembolism (OR, 0.61; 95% CI, 0.49–0.77; P < 0.001), acute renal failure (OR, 0.64; 95% CI, 0.43–0.94; P = 0.022), wound complications (OR, 0.71; 95% CI, 0.53–0.96; P = 0.028), and lower hospitalization cost (34.5% lower) compared with nonelective admissions. Conclusions Our findings serve as a framework for strengthening referral networks for complex cases to centers performing high volumes of cerebral bypass. Also, our study supports improved outcomes in select patients undergoing elective bypass procedures.