1620. Minimally Invasive Bilateral Muscle Splitting Approach for Revision of Lumbar Spine Surgery

Authors: Maureen Darwal, DO; Joseph Koziol, MD; Saikiran Murthy, DO; Otakar Hubschmann, MD (Montclair, NJ)

Introduction: Re-operation on patients that underwent prior lumbar spinal surgery with or without fusion is always challenging. In addition to scarring which is often severe, the anatomical planes are nondistinct and risks of injury to nerve roots or CSF leak are considerable. Methods: We have developed a technique in which revision surgery previously performed using midline incision is performed using paramedian bilateral minimally invasive inter muscular dissection technique using a plane within the sacrospinalis muscle.We have performed a total of twelve (12) procedures on seven (7) males and five (5) females. The ages ranged from 52 to 76. The indications were revision of laminectomy for unilateral radiculopathy and instability in five (5) patients who had two previous surgeries and seven (7) patients who had one. There were three (3) surgeries for construct failure and nine (9) with adjacent segment disease. In addition to decompression, all patients had instrumented fusion at one or more levels. Results: There were no instances of CSF leak, no nerve root injuries and no patient required transfusion. The technique utilizes a modified paramedian Wiltse approach that we have described previously and approaches the revision site by removing completely lateral the facets followed by medial facet. The facets are drilled to leave only thin shell of bone below the level of scar which is lifted with a microdiscectomy. Conclusion: This leads to normal epidural space and the pedicles. The nerve roots are mobilized as needed and the disc space is easily accessed. The details of the technique will be presented.