1. 2019;22;89-95Transforaminal Epiduroscopy in Patients with Failed Back Surgery Syndrome
   Prospective Study
   Martin Avellanal, MD, PhD, Gonzalo Diaz-Reganon, MD, Alejandro Orts, MD, Lucio Gonzalez-Montero, MD, and Irene Riquelme, MD.

BACKGROUND: Epiduroscopy is a useful diagnostic and therapeutic tool for managing failed back surgery syndrome (FBSS). The conventional approach is via either the sacral hiatus or the interlaminar. Major causes of FBSS include epidural fibrosis, disc herniation, and stenosis. When these problems are located at the intervertebral foramen level, it can be difficult to reach the lateral recess and the foramen with the epiduroscope. Transforaminal epiduroscopy could be a useful alternative approach in patients with FBSS located at the foraminal level.

OBJECTIVE: We present a new procedure for lumbar epiduroscopy via a transforaminal approach and its application in patients with FBSS. The technique is described and long-term results are reported.

STUDY DESIGN: This study used a single-arm prospective observational design.

SETTING: The research took place at the University Hospital in Spain.

METHODS: Patients with FBSS suffering severe chronic radicular pain (Numeric Rating Scale [NRS-11] > 7) who had not responded to other treatments were included. Selective root stimulation during a pulsed radiofrequency procedure confirmed the origin of pain by means of an exact reproduction of typical pain. Transforaminal epiduroscopy was performed at the affected level. The severity of fibrosis observed was recorded. The NRS-11 score was reevaluated at 1, 6, and 12 months after the procedure. Any complications related to the treatment were recorded.

RESULTS: Twenty-four patients were included. The mean number of back surgeries was 1.66 (range, 1-5). The basal NRS-11 score was 7.83 (0.14); at 1 month, 3.66 (0.38) (P < 0.001); at 6 months, 4.46 (0.48) (P < 0.01); and at 1 year after treatment, 4.17 (0.51) (P < 0.01). Most patients (54%; 95% CI, 34%-74%) obtained > 50% pain reduction on the NRS-11, maintained during a 1-year follow-up period. No major complications were registered.

LIMITATIONS: The research was limited by the lack of a control group.

CONCLUSIONS: We have described a new procedure for epiduroscopy via the transforaminal approach. It is a useful and safe approach to managing FBSS at the foraminal level and shows better long-term results than other endoscopic procedures.

KEY WORDS: Epidural, epiduroscopy, chronic pain, spinal cord, back surgery