Percutaneous Endoscopic Unilateral Laminotomy and Bilateral Decompression under 3D Real-Time Image-Guided Navigation for Spinal Stenosis in Degenerative Lumbar Kyphoscoliosis Patients: An Innovative Preliminary Study
Authors: Ho Tsung-Yu , Lin Chung-Wei , Chang Chien-Chun , Chen Hsien-Te , Chen Yen-Jen , Lo Yuan-Shun , Hsiao Pan-Hsuan , Chen Po-Chen , Lin Chih-Sheng , Tsou Hsi-Kai 
Published: July 2020

Abstract
Background
The aim of this study is to introduce a new method of percutaneous endoscopic decompression under 3D real-time image-guided navigation for spinal stenosis in degenerative kyphoscoliosis patients without instability or those who could not endure major surgery due to multiple comorbidities. Decompression along using endoscope for kyphoscoliosis patient is technical demanding and may result in unnecessary bone destruction leading to further instability. The O-arm/StealthStation system, a 3D real-time image-guided navigation system, is popular for its ability to provide automated registration with intraoperative, postpositioning computed tomography (CT) with no radiation exposure to operative staffs. With 3D real-time image-guided navigation, we could improve the accuracy of surgery and maintain the spinal stability as preoperative condition.
Methods
In this study, we presented four cases. All patients were over seventy years old female with variable degrees of kyphoscoliosis and multiple comorbidity who could not endure major spine fusion surgery. Percutaneous endoscopic unilateral laminotomy and bilateral decompression under 3D real-time image-guided navigation were successfully performed with following steps. First, the reference pin was introduced over iliac crest. Second, all navigational instruments were registered to the O-arm Stealth Station. Third. With the interlaminar approach, a 8.0 mm dilator followed by operative sleeve was introduced toward the ligamentum flavum. Then the endoscope attached with universal tracker was inserted, and the boundaries of lamina and facet joint were well-identified through the monitor. Finally, unitaleral laminotomy and resection of ligamentum flavum with joy-stick technique for bilateral decompression were performed under the navigation system. Patients’ demographics, image study parameters, and outcome measurements including pre- and post-operative serial visual analog scale (VAS), and Oswestry Disability Index (ODI) were well documented. The follow-up time was one year.
Results
All patients were successfully treated with this technique. Pre- and post-operative MRI showed average dural sac cross sectional area (DSCSA) improved from 81.62 (range 67.34–89.07) to 153.27 (range 127.96-189.73). All preoperative neurological symptoms including radicular leg pain and sciatica improved postoperatively. The mean ODI (%) were 85 (range 82.5–90) at initial visit, 35.875 (range 25–51) at 1 month post-operatively, 26.875 (range 22.5–35) at 6 months post-operatively and 22.5 (range 17.5–30) at 12 months post-operatively (p < 0.05). The mean VAS score were 9 (range 8–10) at initial visit, 2.25 (range 2–3) at 1 month post-operatively, 1.75 (range 1–2) at 6 months post-operatively and 0.25 (range 0–1) at 12 months post-operatively (p < 0.05). There was no surgery-related complication such as inadequate decompression, dural tear, iatrogenic neurological injury, uncontrolled epidural hemorrhage, unnecessary bone destruction with further instability.
Conclusions
To the best of our knowledge, this is the first preliminary study of percutaneous endoscopic laminotomy under O-arm navigation with successful outcomes. The innovative technique may serve as a promising solution in treating spinal stenosis patients with lumbar kyphoscoliosis and multiple comorbidities.