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)


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.


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.


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]).


Overlapping neurosurgery is associated with non-inferior patient outcomes that may be driven by surgeon selection of healthier patients, regardless of specific overlap timing.