Learning Curve Associated with Complications in Biportal Endoscopic Spinal Surgery: Challenges and Strategies

Abstract

Study design: Descriptions of technical strategies to overcome pitfalls associated with early learning periods in biportal endoscopic spinal surgery (BESS).

Purpose: To introduce BESS for lumbar spinal diseases (LSDs) and to inform certain challenges to be overcome in mastering the technique.

Overview of literature: BESS has shown superior benefits including excellent magnification, a wider range of view by dynamic handling of an endoscope and instruments. Clinical reports, however, have not yet been very revealing for its new introduction into minimally invasive spine surgery.

Methods: To evaluate the learning curve for BESS, the procedures for various LSDs by one surgeon were analyzed in the view of shortening of the operating times and reduction of complications. Reviewing of recorded procedures helped in finding the reasons and the implemented solutions.

Results: The 68 cases included 25 for lumbar disc herniation (LDH), 3 for revision for recurred LDH, 39 for lumbar spinal stenosis (LSS) and 1 for synovial cyst. The operation time for the total cases averaged 83.7±33.6 minutes. According to diagnosis, it was 68.2±23.7 minutes for LDH. After the 14th case of LDH, it was nearly constant and close to the average time. One level of LSS needed 110.4±34.4 minutes. Prolonged operation times even in some later cases of LSS were mainly from struggling against blurred vision due to epidural bleeding. There were 7 cases of complications (10.3%) including 2 cases of dural tear, 1 case of root injury, and 4 cases of incomplete decompression on postoperative magnetic resonance imaging. There was no case of symptomatic hematoma or wound infection.

Conclusions: BESS seemed to have a relatively short learning curve period. The overall complication rate in early learning period was 10.3%. These could be avoided by magnified regional views on an endoscope and a clear surgical field by controlling epidural bleeding.

Keywords: Complication; Endoscopic; Lumbosacral; Minimally invasive surgical procedure; Spinal stenosis.

Fig. 1. An endoscopic view. The magnified view showed very small epidural vessels clearly.

Fig. 2. The useful instruments for biportal endoscopic spinal surgery. Angled instruments were very helpful. These instruments had small and smooth heads.

Fig. 3. Preoperative radiographics on the lateral recess stenosis and foraminal stenosis on the right side with calcified lumbar disc herniation in a 58-year old, male patient.

Fig. 4. Postoperative radiographics showed that both lateral recesses and right-sided foramen were decompressed well. An arrowed on endoscopic view indicated an exiting root at the level of the 4–5th lumbar spines.

Fig. 5. The Push-Rock method. A piece of gelfoam was inserted and packed under the lamina with a freer. A lump of bonewax was then rocked on it and smashed to compress the bleeding site.

Fig. 6. Approach views from the left side. (A) An ipsilateral view on the left side after removing the outer layer of ligamentum flavum and laminectomy with a high-speed burr. (B) A contralateral view through the midline showed ligamentum flavum on the right side.