Endoscopic Foraminal Decompression for Failed Back Surgery Syndrome under local Anesthesia

Abstract

BackgroundThe most common causes of failed back surgery are residual or recurrent herniation, foraminal fibrosis and foraminal stenosis that is ignored, untreated, or undertreated. Residual back ache may also be from facetal causes or denervation and scarring of the paraspinal muscles.1–6 The original surgeon may advise his patient that nothing more can be done on the basis of his opinion that the nerve was visually decompressed by the original surgery, supported by improved post-op imaging and follow-up studies such as EMG and conduction velocity studies. Post-op imaging or electrophysiological assessment may be inadequate to explain all the reasons for residual or recurrent symptoms. Treatment of Failed back surgery by repeat traditional open revision surgery usually incorporates more extensive decompression causing increased instability and back pain, therefore necessitating fusion. The authors, having limited their practice to endoscopic MIS surgery over the last 15-20 years, report on their experience gained during that period to relieve pain by endoscopically visualizing and treating unrecognized causative patho-anatomy in FBSS.7MethodsThirty consecutive patients with FBSS presenting with back and leg pain that had supporting imaging diagnosis of lateral stenosis and /or residual / recurrent disc herniation, or whose pain complaint was supported by relief from diagnostic and therapeutic injections (Figure 1), were offered percutaneous transforaminal endoscopic discectomy and foraminoplasty over a repeat open procedure. Each patient sought consultation following a transient successful, partially successful or unsuccessful open translaminar surgical treatment for disc herniation or spinal stenosis. Endoscopic foraminoplasty was also performed to either decompress the bony foramen for foraminal stenosis, or foraminoplasty to allow for endoscopic visual examination of the affected traversing and exiting nerve roots in the axilla, also known as the “hidden zone” of Macnab (Figure 2).8, 9 The average follow up time was, average 40 months, minimum 12 months. Outcome data at each visit included Macnab, VAS and ODI.Fig. 1A diagnostic and therapeutic epidural gram may help identify unrecognized lateral recess stenosis underestimated by MRI. An excellent result from a therapeutic block lends excellent prognosis for a more lasting and “permanent” result from transforaminal endoscopic lateral recess decompression.Fig. 2Kambin's Triangle provides access to the “hidden zone” of Macnab by foraminoplasty. The foramen and lateral recess is decompressed by removing the ventral aspect and tip of the superior articular process to gain access to the axilla between the traversing and exiting nerve. FBSS contains patho-anatomy in the axilla between the traversing and exiting nerve that hides the pain generators of FBSS.ResultsThe average pre-operative VAS improved from 7.2 to 4.0, and ODI 48% to 31%. While temporary dysesthesia occurred in 4 patients in the early post-operative period, all were happy, as all received additional re...

A new concept of transforaminal ventral facetectomy including simultaneous decompression of foraminal and lateral recess stenosis: Technical considerations in a fresh cadaver model and a literature review

“…The elderly often have comorbidities (32) rendering them at high risk for general anesthesia, so surgeries that can be done under local anesthesia are preferable in this age group. However, based on anatomic considerations, only the TF approach for foraminal stenosis has been discussed in the literature (14)(15)(16)(17). In practice, during foraminoplasty via the TF approach, we have sometimes noticed that the traversing nerve root is decompressed at the same time as the exiting nerve, due to wide removal of the superior facet joint on the cranial side ( Figure 3).…”

“…In a report underscoring the importance of foraminal stenosis as a cause of residual symptoms in patients with failed back surgery, Yeung and Gore described 30 patients treated with TF-PED technique in whom foraminoplasty could be performed under local anesthesia (14). The mean visual analog score in these patients improved from 7.2 preoperatively to 4.0 postoperatively and the Oswestry Disability Index from 48% to 31%.…”

Percutaneous endoscopic transpedicle approach for herniated nucleus pulposus in the lumbar hidden zone

“…Some surgeons prefer the percutaneous endoscopic approach for HNP in cases involving high‐grade migration, and good results have been obtained . Yeung and Gore suggested that HNP in the hidden zone can be safely accessed by transforaminal PELD . Ahn et al reported a standardized technique of transforaminal PELD for very high‐grade migrated disc herniation; they obtained excellent or good global outcomes in 84.6% of patients, and the rate of symptomatic improvement was 92.3% .…”

The Role of Endoscopic Surgery in the Treatment of Painful Conditions of an Aging Spine: State of the Art

“…The best method at this time is to distribute information in open access journals and training efforts. Clinical research can still be validated with traditional EBM methods of validation as long as they are also peer reviewed by qualified reviewers [6][7][8]. The treatment algorithm in spine is evolving and changing due to a better understanding of the patho-anatomy, well correlated with its pathophysiology.…”