Awake, Transforaminal Endoscopic Lumbar Decompression Surgery to Treat L5-S1 Adjacent Segment Disease: A Case Series.

ABSTRACT

BACKGROUND: Lumbar radiculopathy secondary to L5-S1 degenerative changes adjacent to a lumbar fusion usually requires extending the fusion to include the degenerative L5-S1 level; this revision surgery can often be a very invasive procedure. OBJECTIVE: To describe outcomes of awake, transforaminal endoscopic decompression surgery for patients presenting with lumbar radiculopathy as a result of L5-S1 degenerative disc disease below lumbar fusions. STUDY DESIGN: Retrospective chart review. METHODS: Awake, endoscopic decompression surgery was performed in 538 patients over a 5-year period from 2014 through 2019 by a single surgeon at a single institution.  The records of 18 consecutive patients who underwent transforaminal lumbar endoscopic decompression surgery to treat radiculopathy secondary to L5-S1 adjacent segment disease were retrospectively reviewed. All included patients were followed for at least 2 years after surgery. All patients were treated at L5-S1 and had fusion constructs that ended at L5. RESULTS: Thirteen men and 5 women patients ranging in age from 38 to 83 (average age of 68.9 ± 11.5) were treated for symptomatic adjacent segment disease at L5-S1 during the 5-year time period. Surgery was successful in all cases, except 2 patients (11%) at 2 years follow-up had recurrent symptomatic pathology at L5-S1 and required additional surgical treatment. The average preoperative visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were 7.5(± 1.3) and 45.3 (± 12.3) respectively. The average 2-year postoperative VAS and ODI scores were 2.4 (± 1.5) and 22.5 (± 9.6) respectively, excluding the 2 patients with recurrent pathology. The average body mass index (BMI) and L5-S1 disc height in the 2-year successful group (n = 16) were 30.6 (± 7.4) and 8.7 mm (± 3.5 mm) respectively; the average BMI and L5-S1 disc height in the 2-year failure group (n = 2) were 25.8 (± 5.9) and 7.9 (± 2.6) respectively. LIMITATIONS: This was a retrospective case series. CONCLUSIONS: Endoscopic spine surgery offers patients with fusions that terminate at L5 a safe and effective option for treatment of lumbar degenerative spine disease at L5-S1 below their fusion constructs. A longer follow-up and a larger prospective study would be necessary to consider the utility of endoscopic compression versus extending the fusion construct.