1369. Association of Overlapping Neurosurgery with Patient Outcomes at a Large Academic Medical Center

Authors: Neil R. Malhotra, MD, FAANS; Prateek Agarwal; Ashwin Ramayya, MD, PhD; Benjamin Osiemo, MS; Stephen Goodrich, BS; Gregory Glauser, BS; Scott McClintock, PhD; H. Isaac Chen, MD; James Schuster, MD, PhD; M. Sean Grady, MD (Philadelphia, PA)

Introduction: As limited data exist on the safety of overlapping surgery, the purpose of this study was to examine the association of overlapping neurosurgery with patient outcomes. Methods: 3,038 routinely scheduled, elective neurosurgical procedures were retrospectively reviewed at a single, multi-hospital academic medical center. Procedures were categorized into any overlap or no overlap and further sub-categorized into beginning overlap (first 50% of procedure only), end overlap (last 50% of procedure only), and middle overlap (overlap at the midpoint). Primary outcomes included mortality, reoperation rate, and readmission rate. Results: 1,030 (33.9%) procedures had any overlap, while 278 (9.2%) had beginning overlap, 190 (6.3%) had end overlap, and 476 (15.7%) had middle overlap. Compared with no overlap patients, patients with any overlap had lower ASA scores (p=0.0018), less prior surgery (p<0.0001), and less prior neurosurgery (p<0.0001), though they tended to be older (p<0.0001) and more likely inpatients (p=0.0038). Any overlap patients had decreased overall mortality (2.8% vs 4.5%; p=0.025), 30 to 90-day readmission rate (3.1% vs 5.5%; p=0.0034), 30 to 90-day reoperation rate (1.0% vs 2.0%; p = 0.03), 30 to 90-day ER visit rate (2.1% vs 3.7%; p=0.018), and future surgery on index admission (2.8% vs 7.3%; p<0.0001). While these patients also had increased home discharge (90.6% vs 87.1%; p=0.0052), procedure time was slightly longer (154.8 vs 151.8 min.; p < 0.0001). Beginning overlap patients also had longer procedure time (171.9 vs 151.8 min.; p<0.0001), but outcomes were otherwise equivalent or improved for overlap sub-categories. Multiple regression analysis validated non-inferior outcomes for overlapping surgery, except for the association of increased future surgery on index admission with middle overlap (OR 3.99; 95% CI [1.91, 8.33]). Conclusion: Overlapping neurosurgery is associated with non-inferior patient outcomes that may be driven by surgeon selection of healthier patients, regardless of specific overlap timing.