Treatment of Soft Tissue and Bony Spinal Stenosis by a Visualized Endoscopic Transforaminal Technique Under Local Anesthesia

Abstract

Objective: To analyze long-term clinical outcomes of endoscopic transforaminal foraminoplasty for foraminal stenosis.

Methods: Long-term 5-year MacNab outcomes, visual analogue scale (VAS) scores, complications, and unintended aftercare were analyzed in a series of 86 patients who underwent endoscopic transforaminal foraminoplasty for foraminal stenosis.

Results: At minimum 5-year follow-up, excellent results according to the MacNab criteria were obtained in 32 patients (37.2%), Good in 40 (46.5%), fair in 11 (12.8%), and poor in 3 (3.5%), respectively. The mean preoperative VAS was 6.15. The mean postoperative and last follow-up VAS was 3.44. Both postoperative VAS and last follow-up VAS were statistically reduced at a significance level of p<0.0001. Postoperative dysesthesia occurred in 9 patients. Another 9 patients had recurrent disc herniations (10.5%). Failure to cure with persistent pain occurred in 3 patients. Two patients developed pain postoperatively stemming from a different level. One patient experienced a postoperative hematoma which ultimately was inconsequential and did not require any additional surgery. Only 3 patients opted for revision endoscopic discectomy and another 2 for revision fusion surgery.

Conclusion: Patients with symptomatic foraminal stenosis may be treated successfully with early transforaminal endoscopic decompression while maintaining favorable long-term outcomes without the need for fusion in the vast majority of patients.

Keywords: Foraminal foraminoplasty; Foraminal stenosis; Lumbar spine; Percutaneous transforaminal decompression; Spinal stenosis.

Fig. 1.

(A-C) Sagittal and axial T2-weighted magnetic resonance imaging images of an 85-year-old male specifically referred for open translaminar decompression because of the severe central, lateral recess, and foraminal stenosis. The patient insisted on endoscopic transforaminal decompression since a right-sided transforaminal epidural steroid injection gave him 70% pain relief. Yeung’s technique specifically uses diagnostic and therapeutic injections as a predictor of the surgical outcome of his trademarked technique. (D, E) Intraoperative chromodiscography and epidurography confirmed concordant pain, severe central and foraminal stenosis and rendered an outline of the exiting nerve root.

Fig. 2.

(A-D) Intraoperative endoscopic images of the same 85-year-old male patient illustrated in Fig. 1. After placement of the working cannula and removal of capsular tissue, the superior articular process (SAP) was exposed. (A) Direct visualization, SAP decompression was facilitated with the use of trephines. (B) An articulating burr was used to further the decompression from lateral to medial and to further resect the tip of the SAP. Alternatively, a laser can be used to remove the tip of the SAP (Supplementary video clip 1). Disc tissue and disc annulus was removed with pituitary rongeurs and cutting forceps (C), which allowed decompression of the traversing nerve root by removing both disc and annular tissue (D). The intradiscal position of the 5.0- or 6.0-mm trephines during the inside-out decompression in the posterior-anterior projection (E), and at the recess in the lateral projection (F) confirm adequate foraminal and central stenosis decompression.

Fig. 3.

(A-D) Intraoperative endoscopic images of the same 85-year-old male patient illustrated in Fig. 1. The final position of the working cannula is shown (A, B) posteriorly and at the medial interpedicular line confirming adequate foraminal and central stenosis decompression. (C) The traversing nerve root (red arrow) is adequately decompressed. A large amount of bone cut by the trephines (D) and disc annulus tissue (E) was removed during the decompression.

Fig. 4.

Age distribution of patients with 5-year follow-up after endoscopic transforaminal foraminoplasty for foraminal stenosis with the superimposed expected normal distribution (black line). Patient’s age ranged from 26 to 84 years of age and averaged 61.9 years. SD, standard deviation.