Management of Thoracal and Lumbar Schwannomas Using a Unilateral Approach without Instability: An Analysis of 15 Cases

STUDY DESIGN: Retrospective case series. PURPOSE: The objectives of this study were to determine and discuss the surgical planning of patients who underwent operations following diagnoses of thoracal and lumbar spinal schwannomas. We also aimed to discuss the application of unilateral hemilaminectomy for the microsurgery of schwannomas. OVERVIEW OF LITERATURE: Schwannomas are located in different regions and sites. These differences require several surgical approaches. Unilateral laminectomy without stabilization of the spine provides a more minimally invasive removal of the tumor. METHODS: In this retrospective study, 15 patients with spinal schwannomas were evaluated with regards to age, sex, onset history, neurological findings, tumor locations, McCormick scale, surgical procedure, and operational results. The lateral approach provides exposure of intradural structures and posterior paraspinal regions. Extensions of tumors cause problem for the surgeon in terms of approach, resectability of the tumor, and stability of the spine. Gross total resection was achieved in all cases, and none of the patients necessary required a fusion procedure. RESULTS: Five patients were males and 10 were females. The age interval was 29-65 years. The tumor was located in the lumbar region in 9 patients, in the thoracic region in 2 patients, and in the thoracolumbar junction in 4 patients. The intradural lesions were removed by laminectomy and the extradural lesions were resected with hemilaminectomy. The paramedian route was used to explore the extraspinal part of the tumor. Costotransversectomy was for the thoracic region. Subtotal resection was performed in 1 patient. Patient symptoms recovered gradually in the postoperative period. CONCLUSIONS: Resection of giant schwannomas is challenging and usually requires a different approach. We describe the complete resection of complex dumbbell or paraspinal schwannomas of the thoracic and lumbar spine by unilateral hemilaminectomy.