Technical Advances in Minimally Invasive Surgery

Abstract

Literature review, technique overview, prospective and retrospective data analysis. To review current minimally invasive surgery (MIS) methods of decompression for lumbar spinal stenosis and present a decompression technique using a flexible microblade shaver system. Several MIS decompression techniques for stenosis have been developed to minimize damage to soft tissues and reduce the amount of posterior element resection. Decompression using linearly configured instruments may not be able to adequately address stenosis in the neural foramen. A flexible microblade shaver system is able to traverse the foramen, removing bone and ligament, using a ventral to dorsal approach, rather than medial to lateral. This enables it to effectively decompress the lateral recess and neural foramen while sparing posterior structures. Brief literature review of current MIS decompression techniques is presented. MIS decompression using a flexible microblade shaver system is described with 1 year outcomes from a small pilot study and a retrospective chart review at 2 centers. A small postmarket pilot study (n = 9) with 1 year results showed positive patient outcomes using Visual Analog Scale (decrease by 73%), Oswestry Disability Index(50% improvement), Zurich Claudication Questionnaire physical function and symptom severity (improved by 72% and 31%, respectively), and Short-Form 36 (SF-36) Physical Component Score (36% improvement). Sixty-seven patients from a retrospective chart review at 2 centers had an average of 2 levels per patient decompressed using a flexible microblade shaver system. No patient has returned for additional surgery and there have been no cases of neurologic impairment. Current decompression techniques may result in inadequate decompression of the neural foramen or excessive resection of the facet joint. MIS decompression using a flexible microblade shaver system represents a way to perform an effective, facet-preserving decompression for patients with lumbar spinal stenosis.