Lightning Podiums: Smorgasboard - Room 802B

Presented by: M. Moawad


A. Buckland(1), J. Moon(1), S. Ramchandran(1), M. Siow(1), P. Zhou(1), D. Vasquez-Montes(1), N. Stekas(1), L. Steinmetz(1), J. Goldstein(1), J. Bendo(1), Y. Kim(1), T. Errico(1), T. Protopsaltis(1), P. Passias(1)

(1) New York University Langone Orthopedic Hospital, Division of Spinal Surgery, New York, NY, United States


Introduction: The surgical invasiveness index (SII) designed by Mirza et al. is a validated instrument to predict EBL and operative time in open (OPEN) spine surgery, however its applicability in hybrid (HYBRID) and minimally invasive (MIS) techniques of lumbar fusion have not been previously described. The aim of this study was to examine the application of a previously validated surgical invasiveness index to OPEN, MIS and HYBRID techniques for lumbar spinal fusions.

Methods: Retrospective Review. Retrospective analysis was performed for patients who underwent ≤4 level lumbar spine surgery by OPEN, HYBRID or MIS technique at a single institution from January 2013 - January 2016. Data collected included patient demographics, surgical and anesthetic data, and intra- and postoperative complications. Based on surgical approach, patients were divided into 3 groups: 1) MIS posterior, 2) Combined (Open anterior/lateral and MIS posterior), and 3) Open posterior. SII, EBL and op time were recorded among groups and evaluated per level fused. SII was also calculated and correlated with EBL and op timeamong the 3 groups and per level fused. Subanalysis by propensity score match (PSM) was performed to control for age, Charlson Comorbidity Index (CCI), and levels fused.

Results: 288 degenerative patients were included (78 MIS, 75 HYBRID, and 135 OPEN). Except for 11 patients in the OPEN group, all had interbody fusions. SII correlated with EBL and Optime in all cohorts (p< 0.001). Mean EBL per level fused was lowest for MIS and highest in OPEN (203 MIS vs. 236 HYBRID vs. 545 mL OPEN, p< 0.001). In contrast, OP time per level was highest in MIS and lowest in open (219 MIS vs 187 HYBRID vs 146 min OPEN, p< 0.001). Mean invasiveness score per level was highest in MIS and lowest in OPEN (8.8 MIS vs 7.9 HYBRID vs 6.8 OPEN, p< 0.001). Time to extubation, ICU stay (LOS) and overall LOS were highest in the OPEN and lowest in MIS. After PSM only an increased incidence of intra-op complications in the HYBRID cohort was noted (17.1%, p=0.02).

Conclusions: Despite less blood loss, MIS & HYBRID fusions have higher invasiveness scores per level fused compared to OPEN fusions. Additionally, hybrid procedures were associated with more intra-operative complications. Current SII does not allow comparison among MIS, HYBRID and OPEN fusion techniques.