Comparison of Outcomes Following a Minimally Invasive Primary versus Revision Lumbar Laminectomy

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, 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, Junyoung Ahn None,

Introduction:
Revision lumbar laminectomies for progressive or recurrent spinal stenosis may warrant greater soft tissue exposure and hospital resource utilization than primary procedures. However, few studies have assessed this relationship and the safety of revision procedures in the setting of MIS techniques.

Aims/Objectives:
To compare the intraoperative parameters and postoperative outcomes between primary and revision minimally invasive lumbar (MIS) laminectomies.

Methods:
A retrospective analysis of 108 patients who underwent a 1 and 2 level MIS lumbar laminectomy for degenerative spinal pathology between 2009-2013 was performed. Patients were separated into primary and revision cohorts. Patient demographics, comorbidity Index (CCI), intraoperative parameters, perioperative outcomes, visual analogue scores (VAS) and postoperative complications were assessed. Statistical analysis was performed with independent sample T-tests for continuous variables and Chi-square analysis for categorical data. An alpha level of <0.05 denoted statistical significance.

Results:
108 lumbar laminectomies were performed, of which 25 cases (23.6%) were revision procedures. Patient demographics, comorbidity burden, smoking status and pre-operative VAS scores were similar between the revision and primary cohorts. There were no significant differences in the mean operative time (63.4±24.6 vs 54.9±21.9, p=0.14), intraoperative blood loss (44.6±10.3 vs 43.6±13.3, p=0.81), length of hospitalization (41.2±75.5 vs 27.9±26.6, p=0.15), and the incidence of perioperative complications (8.7% vs 7.1%, p=0.09) between the revision and primary cohorts, respectively. Postoperative VAS scores were slightly higher in the primary cohort, but this did not reach statistical significance.

Conclusions:
This retrospective analysis demonstrates comparable perioperative outcomes between revision and primary MIS laminectomies. In addition, intermediate-term follow-up demonstrated similar VAS scores and rates of complications. Traditionally, revision open procedures warrant greater disruption of soft tissue structures that may result in worsened outcomes or instability. However, this analysis demonstrates that the utilization of MIS techniques for revision lumbar laminectomy carries similar risks and outcomes to primary procedures.