Lumbar spinal stenosis (LSS) is a common debilitating issue in older patients. Open laminectomies traditionally are the standard treatment for LSS; however, minimally invasive surgery (MIS) has recently become a popular option to facilitate recovery and improve efficiency of care regarding spine procedures.
Guiot and colleagues described the technique for an MIS decompressive lumbar laminectomy procedure.1 The surgery may represent an important strategy to improve the efficiency of care for patients with severe LSS. Several authors have reported clinical benefits with the MIS lumbar laminectomy, leading to a significant improvement in the Oswetry Disability Index (ODI) 25 in the degenerative stenosis group in cases of LSS.2-5 In a recent reviewof 13 studies Wong and colleagues concluded that the MIS laminectomy was efficacious in terms of symptomatic relief and patient satisfaction for patients with LSS.6 Further, Rosen and colleaguesfound a significant improvement in the ODI scores and in the Short Form-36 body pain and physical functions scores in patients aged ≥ 75 years.7
Perioperative measures, including blood loss and narcotic consumption, have been shown to significantly decrease with MIS surgery compared with open decompression.8,9 Decreased narcotic use is of particular interest for the geriatric population because it is expected to allow those patients to remain more physically active and mentally agile.10
Also, long-term success is important when assessing the efficacy of new MIS procedures. Oertel and colleagues found that 85% of patients reported long-term success after unilateral laminotomy of bilateral decompression (ULBD).11 These results indicate that a MIS laminectomy is effective in older patients with LSS and neurogenic claudication.
Although there are numerous MIS approaches to alleviating LSS, more research is needed to determine whether it is superior to the open laminectomy.9,12,13 Skovrliand and colleagues reviewed publications comparing ULBD and open laminectomies and determined that currently insufficient evidence exists to define which technique leads to more positive outcomes.14 Thus, the purpose of this study is 2-fold. First, this study adds to the current research by comparing estimated blood loss and length of stay (LOS) for microscopic MIS laminectomy vs traditional laminectomy. Second, this study aims to address the difference in health care costs between the 2 types of surgery in the VHA.
The U.S. health care system is facing several challenges and in particular pressure for cost reduction.15 VA hospitals are not exempt from those challenges, and their operating budgets are influenced by political and economic factors.16 Because of those challenges, cost-effectiveness is gaining importance.7 Future decisions for procedure coverage and reimbursement rates are likely to consider ratios like the cost to quality-adjusted life-years (QALY). Improving this ratio requires a reduction of cost and/or an improvement in outcome.
Minimally invasive spine surgery (MISS) may lower the cost of spine procedures. Wang and colleagues reported that minimally invasive posterior lumbar interbody fusion (PLIF) led to shorter stay and lower blood loss compared with traditional PLIF.17 These improvements led to about $8,000 in savings for a single-level PLIF.17
Lumbar degenerative disease is a frequently encountered condition, and lumbar laminectomy is one of the most frequently performed spine procedures at VA hospitals. Consequently, MISS may be an important strategy for the VA to face systematic challenges. At the Southern Arizona VA Health Care System (SAVAHCS) in Tucson, the authors converted lumbar laminectomies from traditional open surgery to a MIS procedure using a tubular retractor system and a paramedian approach. To the authors’ knowledge, no studies have evaluated outcomes and cost efficiency of MIS surgery at the VA. The results of such a study may be instrumental in choosing which surgery is appropriate in a patient-centered health care model.
Material and Methods
Fifty veterans with severe lumbar stenosis and neurogenic claudication underwent a 1- or 2-level laminectomy at SAVAHCS (Table). A traditional laminectomy was performed for all patients until conversion to the MIS procedure, then all subsequent patients underwent the microlaminectomy. There was 1 female patient in each group. The preoperative magnetic resonance imaging (MRI) of the patients showed severe spinal canal stenosis defined radiographically by the absence of cerebrospinal fluid signal at the affected level on MRI (Figures 1A and 2A) and clinically by the presence of neurogenic claudication.
Procedure
The open laminectomies were performed in a traditional midline approach with removal of the spinous process along with the lamina bilaterally to provide spinal canal decompression (Figure 2).
The MISS laminectomies were performed through a small unilateral paramedian incision created 1.5 cm from the midline.1 A tubular retractor system was used, and the laminectomy was performed under microscope magnification. A laminotomy initially was completed ipsilateral to the side of the incision until the ligamentum flavum and the lateral recess of the spinal canal were identified. The tube was then aimed medially so that the base of the spinous process was identified and resected. The ligamentum flavum was dissected from the undersurface of the contralateral lamina. The contralateral lamina then was resected using a high-speed drill. Finally, the ligamentum flavum was resected, and the dura was exposed. The cranial-caudal extent of the resection was confirmed using fluoroscopy. The technique allowed for significant canal expansion (Figures 1A, B, C, and D).