530 - The Transforaminal Endoscopic Approach Is Effective for the Treatment...

#530 The Transforaminal Endoscopic Approach Is Effective for the Treatment of FBSS Caused by Recurrent HNP and Lateral Stenosis

MIS Techniques and Outcomes

Poster Presented by: A. Yeung

Author(s):

A.T. Yeung (1)

(1) Desert Institute for Spine Care, Phoenix, AZ, USA

Abstract

Introduction: Failed back surgery syndrome due to recurrent herniation and foraminal stenosis, estimated at 16% in the literature, is common. While conventional surgery for recurrent HNP is nearly as successful as the index procedure, failure due to lateral stenosis is under recognized, and most patients are given no options other than decompression and fusion as a “salvage procedure”.

Methods: 40 consecutive patients with FBSS who elected to undergo Selective Endoscopic Discectomyä and foraminoplasty in a spine group practice was reviewed. Prospective outcome data included modified MacNab, VAS and ODI. Data was collected at the initial office visit, pre-operative and postoperative visits, and final follow up. The foraminal endoscopic approach was a shared patient/surgeon decision. All patients wanted to avoid fusion, even in the face of degenerative and Isthmic grade I spondylolisthesis. All procedures were performed at an ambulatory surgical center in a spine group practice specializing in a MIS setting. The average follow up time was, minimum 12 months, average 40 months.

Results: In the 40 Cases of recurrent disc herniation and foraminal stenosis, average VAS was 7.2, improved to 4.0 and ODI from 48% to 31% Endoscopic foraminoplasty was performed to either decompress the bony foramen for foraminal stenosis or simply to enlarge the foramen to allow for visual confirmation of the axilla containing the traversing and exiting nerve. “Complications” included dysesthesia in 4 patients within the 2 week post-operative period. All were temporary. Patient satisfaction was high, as all were satisfied with their initial decision in order to avoid “open” surgery even if they hoped for more back pain relief than they received from the procedure. Those wanting more back pain relief opted for dorsal endoscopic rhizotomy.

Conclusions: The transforaminal endoscopic approach is effective for FBSS due to recurrent HNP and lateral stenosis. Lateral stenosis is often missed by the original index surgeon. Failed index surgery usually involves failure to recognize patho-anatomy in the “hidden zone of the foramen housing the traversing and the exiting nerve, including the DRG. The approach effectively decompresses the foramen “hidden zone” and does not further destabilize the spine. It avoids going through the previous surgical site. Residual axial back pain may be improved further with dorsal endoscopic rhizotomy in lieu of fusion, as foraminal decompression is a MIS technique that does not “burn bridges” for a more conventional fusion approach. Endoscopic foraminal decompression will at least add to the surgical armamentarium of FBSS. A video demonstration of the technique will be shown pending time available.