Ultrasonic bone scalpel for thoracic spinal decompression: case series and technical note.

BACKGROUND: Thoracic spinal stenosis (TSS) is a rare but intractable disease that fails to respond to conservative treatment. Thoracic spinal decompression, which is traditionally performed using high-speed drills and Kerrison rongeurs, is a time-consuming and technically challenging task. Unfavorable outcomes and high incidence of complications are the major concerns. The development and adaptation of ultrasonic bone scalpel (UBS) have promoted its application in various spinal operations, but its application and standard operating procedure in thoracic decompression have not been fully clarified. Therefore, the purpose of this study is to describe our experience and technique note of using UBS and come up with a standard surgical procedure for thoracic spinal decompression. METHODS: A consecutive of 28 patients with TSS who underwent posterior thoracic spinal decompression surgery with UBS between December 2014 and May 2015 was enrolled in this study. The demographic data, perioperative complications, operation time, estimated blood loss, and pre- and postoperative neurological statuses were recorded and analyzed. Neurological status was evaluated with a modified Japanese Orthopaedic Association (JOA) scale, and the neurological recovery rate was calculated using the Hirabayashi's Method. RESULTS: Thoracic spinal decompression surgery was successfully carried out in all cases via a single posterior approach. The average age at surgery was 49.7 ± 8.5 years. The mean operative time of single-segment laminectomy was 3.0 ± 1.4 min, and the blood loss was 108.3 ± 47.3 ml. In circumferential decompression, the average blood loss was 513.8 ± 217.0 ml. Two cases of instrument-related nerve root injury occurred during operation and were cured by conservative treatment. Six patients experienced cerebrospinal fluid (CSF) leakage postoperatively, but no related complications were observed. The mean follow-up period was 39.7 ± 8.9 months, the average JOA score increased from 4.7 before surgery to 10.1 postoperatively, and the average recovery rate was 85.8%. CONCLUSIONS: The UBS is an optimal instrument for thoracic spinal decompression, and its application enables surgeons to decompress the thoracic spinal cord safely and effectively. This standard operating procedure is expected to help achieve favorable outcomes and can be used to treat various pathologies leading to TSS.