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.