The Anterior Extraperitoneal Replacement of the Intervertebral Disk L5/S1—Safe Solution for Treatment of Degenerative Disk Disease. Experience with 187 Patients
Authors: Hrabalek L. 
Published: June 2012

Introduction Despite increased use of anterior spinal surgery, there is little documentation of the specific types and frequencies of complications associated with its use. Review of the spinal surgery literature revealed a dearth of studies that address the morbidity and mortality rates in large samples of patients who had undergone anterior surgery specifically at level L5/S1. The aims of this study were to report prospectively the incidence and specific types of perioperative complications that occur with minimally invasive anterior retroperitoneal spinal surgery performed at level of the L5/S1 intervertebral disk. Materials and Methods We reviewed all cases of anterior surgery at level L5/S1, treated at the Department of Neurosurgery from January 2001 to June 2011. The study group consisted of 187 patients: 111 women and 76 men, average age 45 years, range 24 to 76 years. The preoperative diagnosis was degenerative disk disease in 96 (51%), failed back surgery syndrome (FBSS) in 55 (30%) and spondylolisthesis in 36 patients (19%). They suffered from low back pain (LBP) and radiculopathy itself and conservative treatment was not effective for a minimum of 6 months. The diagnosis was established using generally accepted methods including history-taking and physical examination, radiography and magnetic resonance imaging (MRI) of the lumbosacral (LS) spine. Total 69 (37%) patients had undergone one or more prior abdominal surgeries including appendectomy in 34 (18% of 187 patients), Pfannenstiel incision in 40 (36% of 111 female); and cholecystectomy in 4, gastric surgery and inguinal hernia in 2 each and umbilical hernia in 1. The whole operation, including surgical approach, was performed by an experienced neurosurgical team. ALIF (Anterior Lumbar Interbody Fusion) was performed in 155 patients, including 96 patients with stand-alone fusion, 12 patients with concomitant anterior plating (Oracle plate, Synthes, USA) and 47 patients with additional posterior TP (transpedicular) fixation (USS, Synthes, USA). Arthroplasty (TDR) was done in 32 patients. The surgical steps in the minimally invasive anterior retroperitoneal approach from the right side to disk L5/S1 are described. All surgical intraoperative anatomical anomalies and complications directly related to the anterior spinal surgery were documented. Results Intraoperative pathological-anatomical anomalies were found in 38 patients (20%). We had no serious complications such as death, excessive intra- or postoperative bleeding, thromboembolism, infection, visceral injury, ileus, LS plexus injury, retrograde ejaculation or sterility. Intra- and postoperative minor complications were found in 24 patients (11%), the main intraoperative complication was peritoneal opening without visceral injury in 9 patients (5%), and the main postoperative complication was weakness of the right abdominal wall in 5 patients (2.5%). At follow-up we found no hardware failure on X-ray (implant displacement or pseudoarthrosis). Clinically, no patient was worse after surgery. Total 176 patients were satisfied with the surgery and reported improvement, 11 patients were not improved and we later indicated posterior TP fixation at L5/S1 segment for enhancement of the stability. Conclusion Retroperitoneal access and surgery at level L5/S1 disk space is a safe procedure when performed by a knowledgeable and experienced spine team and can be used with confidence when the nature of a patientás spinal disorder dictates its use. 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