Minimally Invasive Lumbar Laminectomy: A Medicare Beneficiaries Analysis

Presented at SMISS Annual Forum 2014
By Abbas Naqvi BS
With Kern Singh MD, 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: Abbas Naqvi BS None 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:
Medicare (MC) recipients encompass a myriad of patients with symptomatic degenerative lumbar pathology. These patients often carry a significant comorbidity burden and are likely to benefit from less invasive techniques. However, the surgical outcomes and safety of minimally invasive lumbar laminectomy have been poorly studied in this population.

Aims/Objectives:
To assess the surgical outcomes and safety of a primary 1 and 2 level minimally invasive (MIS) lumbar laminectomy in Medicare beneficiaries.

Methods:
A total of 85 primary 1 and 2 level MIS lumbar laminectomy procedures for degenerative spinal pathology were retrospectively analyzed. Patients were separated as a function of their MC payer status (MC vs non-MC). 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:
Of the 85 patients who underwent an MIS lumbar laminectomy, 25 (30.9%) were Medicare beneficiaries. MC patients were on average older and demonstrated a greater comorbidity burden. The proportion of smokers and the pre-operative VAS scores were comparable between the study cohorts. The MC cohort incurred a longer operative time (64.4±28.5 vs 50.8±17.2 min, p<0.05) and hospitalization (41.6±31.9 vs 21.7±21.4 hours, p<0.05) than the non-MC cohort. In addition, MC patients incurred a greater rate of intraoperative incidental durotomies (8.0% vs 0.0%, p<0.05) and in-hospital medical complications (12.0% vs 0.0%, p<0.05). In contrast, the payer status did not significantly impact the postoperative VAS scores.

Conclusions:
Medicare patients incur significantly greater hospital resource utilization most likely secondary to an increased comorbidity burden. Additionally, this population typically suffers from a greater degree of spinal stenosis. These findings may help explain the increased surgical complication rate and hospitalization associated with this challenging population. Regardless, despite greater hospital resource utilization and increased surgical complication rate, Medicare patients who underwent an MIS lumbar laminectomy demonstrated significant improvements in pain that were comparable to that of the non-MC cohort.