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

Abstract

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) has 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 were enrolled in this study. The demographic data, perioperative complications, operation time, estimated blood loss, 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±1.4min and the blood loss was 108.3±47.3ml. In circumferential decompression, the average blood loss was 513.8±217.0ml. 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.

Angled Ultrasonic Bone Curette‐Assisted Circumferential Decompression for Thoracic Myelopathy Caused by Severely Anterior Ossification

“…Sun et al . augmented the surgical procedure by maintaining the last thin layer of ossification rather than penetrating it, reducing the incidence of UBC‐related nerve root injuries significantly 22 , while Tang et al . suggested breaking the distal end of the plaque to press it down slightly and separating the adhesion with direct vision under the microscope to minimize disturbance to the spinal cord 17 .…”

“…However, as a result of ventral adhesion separation of the dural sac and the surgical instrument prying anterior ossification, electrophysiological early warning events occurred sometimes 16,17 . Sun et al augmented the surgical procedure by maintaining the last thin layer of ossification rather than penetrating it, reducing the incidence of UBC-related nerve root injuries significantly 22 vision under the microscope to minimize disturbance to the spinal cord 17 . Despite this, surgical instruments are still used to gouge or rotate the ossification beneath the spinal cord.…”

“…Advantages of this device, such as precision safety, self-irrigation cooling system, soft tissue protection, and better hemostasia, make it a useful instrument for treating various spinal disorders without causing excessive mechanical and thermal injury 20,21 . Especially for patients with thoracic myelopathy caused by severely anterior ossification, the application of UBC could effectively reduce the probability of spinal cord injury after circumferential decompression and improve the recovery rate of spinal cord function in comparison with conventional instruments 16,22 .…”

Efficacy and Safety of the Ultrasonic Bone Scalpel in Lumbar Laminectomies

“…If improperly managed postoperatively, iatrogenic durotomies can increase the risk of developing refractory headache, intracranial hypotension, pseudomeningoceles, or, in rare cases, remote cerebellar hemorrhage 12,[22][23][24][25] . The UBS has been utilized in spine surgery with the proposed advantage of decreased operative times, higher volume of bone graft retention, and possibly fewer incidental durotomies 14 . While previous studies have reported improved operative speed and decreased complications for laminectomies performed by the UBS in the cervical and thoracic regions, the efficacy of the UBS for lumbar laminectomies has remained understudied 14,16,17 .…”

“…The ultrasonic bone scalpel (UBS) is a tool that uses high-frequency oscillation to create localized tissue disruption 13 . By vibrating at high frequency, micromovements of the blade surface preferentially cut through hard surfaces such as bone 14 . This preferential cutting occurs because the higher natural elasticity of soft tissue structures such as the dura mater allows greater tolerance of vibratory strain 15 .…”