Visualized Endoscopic Transforaminal Technique Shows Efficacy in Foraminal Stenosis

Peer Reviewed

A majority of patients with foraminal spinal stenosis showed good to excellent 5-year outcomes from endoscopic transforaminal decompression using Yeung’s technique, according to a retrospective review of cases performed by a single surgeon. Only approximately 2% of patients eventually underwent revision fusion surgery, researchers reported in the March issue of Neurospine.

“The implication of the findings is that outcomes from endoscopic transforaminal foraminoplasty for foraminal stenosis is dependent on the surgeon’s experience,” said lead author Anthony T. Yeung, MD, Clinical Professor of endoscopic spine surgery at the University of New Mexico School of Medicine, Albuquerque, NM, and orthopaedic spine surgeon at the Desert Institute for Spine Care, Phoenix, AZ. “I had more than 15 years of experience performing this procedure on 5,000 cases before starting the study.”

spinal stenosisUsing Yeung's technique, a majority of patients with foraminal spinal stenosis showed good to excellent 5-year outcomes. Photo Source:

Dr. Yeung’s Technique

Dr. Yeung and colleagues identified 86 consecutive patients (ages 26 to 84 years: mean, 61.9 years; 25.6% female) with degenerative foraminal stenosis who underwent endoscopic foraminoplasty decompression performed using Dr. Yeung’s percutaneous endoscopic lumbar decompressive technique.

This “inside-out” technique involves placing the working sheath into the intervertebral disc, with the exiting nerve root retracted and protected. The procedure is performed under continuous direct videoendoscopic visualization to target the pain generator.

All patients in this study had clinical signs of lumbar radiculopathy, dysesthesias, and decreased motor function; imaging evidence of foraminal or lateral recess stenosis; and failed to respond to at least 12 weeks of non-operative treatment (eg, physical therapy, steroid injections). Patients with severe central stenosis (<100 mm2) or instability (anterolateral translation >3–5 mm or rotation >10° to 15° in dynamic views) were excluded from the analysis.

Primary outcomes were assessed at 5 years post-operatively using the MacNab criteria.

Majority of Patients Experienced Good to Excellent Results

As shown in the Figure, 83.7% of patients had good or excellent results at 5 years following foraminoplasty. Significant reductions in pain on the Visual Analogue Scale were found post-operatively (mean, 3.44: P<0.0001) as well as at the last follow-up visit (mean, 3.44; P<0.0001), compared with pre-operative levels (mean, 6.15).

MacNab clinical outcomes bar chartFigure. MacNab clinical outcomes in patients with foraminal stenosis who underwent visualized endoscopic transforaminal foraminoplasty. Data extracted from Yeung et al.
Figure. MacNab clinical outcomes in patients with foraminal stenosis who underwent visualized endoscopic transforaminal foraminoplasty. Data extracted from Yeung et al.

Sequelae and Complications

Nearly two-thirds of patients (72.1%) had no post-operative sequelae or complications. The most common sequelae/complications were dysesthesia and recurrent disc herniation (10.5% for both outcomes). In addition, the majority of patients did not require additional post-operative treatment (65.1%). Transforaminal epidural steroid injection was the most common post-operative treatment (26.7%). Three patients underwent repeat foraminoplasty for recurrent disc herniation, two patients underwent L3-L5 or L3-L4 fusion, and one patient each underwent foraminotomy or hemilaminectomy.

Conclusions and Future Research

The authors concluded that “foraminal stenosis can be treated favorably with early transforaminal endoscopic decompression” and that delaying surgical decompression seems “unwarranted given the direct access to the stenotic neuroforamen with the endoscopic transforaminal approach and its low propensity to destabilize the lumbar spinal motion segment.”

“In some patients, traditional decompression may require extensive decompression to effectively relieve the patient of lateral recess or foraminal stenosis, iatrogenically creating the need for fusion, which in turn may be considered too aggressive,” the authors wrote. They added that such patients may forgo surgery, leading to persistent and increasing disability, necessitating fusion. Percutaneous endoscopic foraminal decompression may be an effective alternative to translaminar decompression, by preventing instability from facet decompression. In these patients, given that only 2 patients in this study eventually underwent revision fusion, the researchers the advantages of a transforaminal approach.

Dr. Yeung and colleagues are continuing to follow more patients over the next 3 years, and to compare his “inside-out” transforaminal technique to “the outside-in” technique promoted by Hoogland. Yeung expects to see a greater percentage of patients with good to excellent results given that his surgical expertise has improved over this period, and endoscopic surgical instrumentation continues to improve, he said. In addition, the researchers will stratify patients to determine the impact of individual patient-specific pain generators on surgical outcomes.

Dr. Yeung emphasized that outcomes of this procedure are surgeon dependent, and that the findings in the current study are not applicable to surgeons who are just learning to perform this procedure. In addition, this procedure is not currently indicated for patients with severe spinal deformity, he noted.

Dr. Yeung is the developer of an Endoscopic Spine system trademarked as the YESS™ system.

Updated on: 05/03/19
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Outpatient Transforaminal Endoscopic Decompression for Spinal Stenosis Linked to Cost Savings
Anthony T. Yeung, MD
Orthopaedic Surgeon
Desert Institute for Spine Care

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