MINIMALLY INVASIVE ANTERIOR RETROPERITONEAL APPROACH TO THE LUMBAR SPINE - EMPHASIS ON THE LATERAL BAK

Study Design. Eighteen patients with lumbar instability from fractures , postlaminectomy syndrome, or infection were treated prospectively wi th minimally invasive retroperitoneal lumbar fusions. Objectives. To d etermine if interbody Bagby and Kuslich fusion cages and femoral allog raft bone dowels can be inserted in a transverse direction via a later al endoscopic retroperitoneal approach to achieve spinal stability. Su mmary of Background Data. Endoscopic spinal approaches have been used to achieve lower lumbar fusion when instrumentation is placed through a laparoscopic, transperitoneal route. However, complications of using this approach include postoperative intra-abdominal adhesions, retrog rade ejaculation, great vessel injury, and implant migration. This stu dy is the first clinical series investigating the use of the lateral r etroperitoneal minimally invasive approach for lumbar fusions from L1 to L5. Methods. Eighteen patients underwent anterior interbody decompr ession and/or stabilization via endoscopic retroperitoneal approaches. In most cases, three 12-mm portals were used. Two parallel transverse interbody cages restored the neuroforaminal height and the desired am ount of lumbar lordosis was achieved by inserting a larger anterior ca ge, distraction plug, or bone dowel. Results. The overall morbidity of the procedure was lower than that associated with traditional ''open' ' retroperitoneal or laparotomy techniques, with a mean length of hosp ital stay of 2.9 days (range, outpatient procedure to 5 days). The mea n estimated intraoperative blood loss was 205 cc (range, 25-1000 cc). There were no cases of implant migration, significant subsidence, or p seudoarthrosis at mean follow-up examination of 24.3 months (range, 12 -40 months) after surgery. Conclusions: This preliminary study of 18 p atients illustrates that endoscopic techniques can be applied effectiv ely through a retroperitoneal approach with the patient in the lateral position. Unlike the patients who had undergone transperitoneal proce dures described in previous reports, in these preliminary 18 patients, there were no cases of retrograde ejaculation, injury to the great ve ssels, or implant migration.