Surgical and Clinical Outcomes Associated with Minimally Invasive and Open Lumbar Diskectomy

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, Aamir Iqbal 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, Aamir Iqbal BS None, Junyoung Ahn None,

Introduction:
Although technically challenging, minimally invasive techniques to the lumbar spine have been demonstrated to be a safe and effective alternative to open approaches. Despite growing popularity, the potential advantages of MIS procedures over open techniques have not been well elucidated in the setting of lumbar diskectomy.

Aims/Objectives:
To contrast the intraoperative parameters and surgical outcomes between minimally invasive (MIS) and open 1 and 2 level lumbar diskectomies.

Methods:
A retrospective analysis of 330 patients who underwent a primary 1 and 2 level lumbar diskectomy for degenerative spinal pathology between 2007-2013 was performed. The patients were separated based upon the surgical technique (MIS vs Open). Patient demographics, comorbidity Index (CCI), intraoperative parameters, postoperative outcomes, 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:
Of the 330 cases included in this study, 252 (76.4%) were performed utilizing MIS techniques. Patient demographics, smoking status, comorbidity burden (CCI), and preoperative visual analogue scores (VAS) were comparable between cohorts. The MIS cohort demonstrated a reduced mean operative time (40.4±19.5 vs 59.3±18.9, p<0.05), blood loss (39.2±14.6 vs 67.8±46.2, p<0.05), and length of hospitalization (13.9±14.4 vs 20.2±19.3, p<0.05) when compared to the open cohort. In addition, MIS treated patients incurred a reduced rate of incidental durotomy (5.1% vs 0.4%, p<0.05). All patients reported symptomatic improvement, however, MIS treated patients demonstrated higher postoperative VAS scores at 12 weeks (3.1±2.9 vs 1.3±2.2, p<0.05), and 6 months (2.9±3.1 vs 0.9±3.0, p<0.05). The surgical technique did not significantly impact the rate of reherniation or revision/reoperation.

Conclusions:
This analysis demonstrated that MIS techniques for lumbar diskectomy are associated with reduced hospital resource utilization and a reduced rate of incidental durotomy. In addition to these technical advantages, both cohorts demonstrated similar rates of re-herniation and revision/reoperation. As such, MIS lumbar diskectomy offers the advantage of less resource utilization while providing comparable postoperative outcomes to an open procedure.