Minimally Invasive versus Open Lumbar Diskectomy: A Survivorship Analysis

Presented at SMISS Annual Forum 2014
By Kern Singh MD
With Sreeharsha Nandyala BA, Alejandro Marquez-Lara MD, Islam Elboghdady , Eric Sundberg MD, Hamid Hassanzadeh MD, Anton Jorgensen MD, Khaled Aboushaala MD, Blaine Manning BS, Junyoung Ahn ,

Disclosures: Kern Singh MD A; CSRS Resident Grant. B; DePuy, Zimmer, Stryker, CSRS, ISASS, AAOS, SRS, Vertebral Column - ISASS. D; Avaz Surgical, LLC, Vital 5, LLC. F; Zimmer, Stryker, Pioneer, Lippincott Williams & Wilkins, Th Sreeharsha Nandyala BA None, Alejandro Marquez-Lara MD None, Islam Elboghdady None, Eric Sundberg MD None, Hamid Hassanzadeh MD None, Anton Jorgensen MD None, Khaled Aboushaala MD None, Blaine Manning BS None, Junyoung Ahn None,

Introduction:
Minimally invasive techniques to the lumbar spine are associated with potential advantages with regards to soft tissue injury, operative time, and postoperative recovery compared to open approaches. Despite growing popularity, there is a paucity in the literature comparing the lasting effects of MIS and open techniques for lumbar diskectomies.

Aims/Objectives:
To compare the one-year survival between minimally invasive (MIS) and open 1 and 2 level lumbar diskectomies.

Methods:
A consecutive series of 269 patients who underwent a primary 1 or 2 level lumbar diskectomy for degenerative spinal pathologies between 2007-2013 was retrospectively analyzed. Patients were stratified based upon the surgical technique (MIS vs Open) and assessed with regards to patient demographics and comorbidity burden. A Kaplan-Meier survival analysis was performed to determine the incidence and prevalence of revision surgeries at 12-months. Differences in survival distributions were identified with the Log-Rank comparison test and a p-value of <0.05 was utilized to denote statistical significance.

Results:
Of the 269 cases included in this study, 193 (71.7%) were performed utilizing an MIS technique and 76 (28.3%) with an open approach. There were no significant differences in patient age (41.5±13.0 vs 41.2±12.0, p=0.87), race, comorbidity burden (CCI: 1.38±1.62 vs 1.57±1.68, p=0.50), or body mass index (BMI: 29.5±6.6 vs 29.9±7.2, p-=0.73) between the MIS and open cohorts. 12-months after index lumbar diskectomy, 31 (11.5%) patients required a reoperation for persistent or worsening symptoms. Kaplan-Meier analysis predicted a survival rate of 93.4% (n=71/76) at one-year in the open cohort and 86.5% (n=167/193) in the MIS cohort. Comparison analysis demonstrated no significant differences in survival distribution between the two cohorts (Log-Rank: Chi-square 2.28, p=0.13). In addition, the index surgical technique did not significantly impact the type of revision procedure (arthrodesis vs decompression, p=0.17).

Conclusions:
With revision surgery as the end-point, this analysis demonstrated that MIS techniques for lumbar diskectomy procedures are associated with comparable one-year survival to traditional open approaches. As such, in addition to the potential peri-operative advantages of these novel techniques, patients who undergo an MIS lumbar diskectomy can expect similar mid-term benefits to those undergoing a traditional open procedure.