Biportal Endoscopic Spinal Surgery for Lumbar Spinal Stenosis

Abstract

Biportal endoscopic spinal surgery (BESS) is a minimally invasive spinal surgery, which is basically similar to microscopic spinal surgery in terms of the use of floating technique and technically similar to conventional percutaneous endoscopic spinal surgery in terms of the use of endoscopic or arthroscopic instruments. Using two independent portals (viewing and working) and maintaining a certain distance from the bony and neural structures allow closer access to the target lesion through a panoramic view by free handling of the scope and instruments rather than through a fixed view by docking into the Kambin's triangle. Minimally invasive surgery allows for reduced dissection and inevitable muscle injury, preserving stability and reducing risks of restabilization. The purpose of fusion surgery is the same as that of the three surgical techniques stated above. Its wider range of view helps to overcome limitations of conventional endoscopic spinal surgery and to supplement the weak points of microscopic spinal surgery, such as limited working space in a tubular retractor and difficulty in accessing the contralateral area. This technique provides an alternative to unilateral or bilateral decompression of lumbar central spinal stenosis, foraminal stenosis, low-grade spondylolisthesis, and adjacent segment degeneration. Early clinical outcomes are promising despite potential for complications, such as dural tearing and postoperative epidural hematoma, similar to other procedures. Merits of BESS include decreased postoperative infection rate due to continuous irrigation throughout the procedure and decreased need for fusion surgery for one- or two-level lumbar stenosis by wide sublaminar and foraminal decompression with minimal sacrifice of stabilizing structures.

Keywords: Arthroscopy; Endoscopy; Minimal invasive surger; Spinal stenosis.

Fig. 1.

(A) Set up of BESS. (B) Special instruments for BESS. BESS, biportal endoscopic spinal surgery.

Fig. 2.

(A–D) Two independent portals for the interlaminar approach.

Fig. 3.

(A) Intraoperative gross photo during biportal endoscopic spinal surgery. (B–D) Endoscopic image of the dura, contralateral traversing root (blue arrow), and ipsilateral traversing root (red arrow). Preoperative (E, G) and postoperative (F, H) T2-weighted magnetic resonance images of a patient who underwent interlaminar decompression for spinal stenosis at L4–L5.

Fig. 4.

(A) Portal placement for the transforaminal approach for a lumbosacral lesion. (B, C) A radical artery located above the exiting root found during transforaminal decompression. (D) An endoscopic image of partial removal of the superior articular process to allow foraminal decompression at the 12 o’clock position. (E) Endoscopic image of the exiting root after foraminal decompression. TP, transverse process.

Fig. 5.

Preoperative (A, C) and postoperative (B, D) T2-weighted magnetic resonance images of a patient who underwent transforaminal decompression for foraminal stenosis at L5–S1 with far lateral disc herniation.

Fig. 6.

(A) Portal locations of three different biportal endoscopic approaches. (B) Space between traversing and exiting root for cage insertion. (C) Intraoperative photograph. Fluoroscopy was used when bone graft procedure was conducted. (D) Once the cage is inserted, two semi-tubular retractors protect the traversing and exiting roots. (E) Preoperative plain radiograph of a patient with spondylolisthesis at L4–L5. (F) Endoscopic image showing the intervertebral disc space with complete removal of the cartilaginous endplate. (G, H) Intraoperative anteroposterior and lateral fluoroscopic views showing reduction of spondylolisthesis at L4–L5 and the position of the cage. IPA, ipsilateral posterior approach; TLIF, transforaminal lumbar interbody fusion; FLA, far lateral approach.