Extreme cases in percutaneous transforaminal endoscopic surgery: case series and brief review of the literature.

PURPOSE: Percutaneous transforaminal endoscopic decompression (PTED) is a minimally invasive method of surgical treatment of miscellaneous spinal conditions. We describe our experience with PTED in extreme cases of foraminal stenosis (FS) in adult degenerative scoliosis (ADS), recurrent foraminal stenosis (RFS) after previous open decompression surgery and adjacent segment disease (ASD) after previous lumbar fusion.

METHODS: Twenty-one (21) patients with FS encountered in the clinical framework of ADS ( n  = 6), previous open decompression surgery ( n  = 8) and ASD ( n  = 7) were prospectively reviewed. Patients were preoperatively assessed via clinical and radiologic evaluation. All patients underwent PTED in 2018-2019. Postoperative evaluation was conducted with clinical examination and evaluation of Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) and modified MacNab criteria in predetermined chronic intervals in a 1-2 years follow-up.

RESULTS: All patients were successfully managed with PTED. Operated levels were L3-L4 (19.0%), L4-L5 (52.4%) and L5-S1 (28.6%). No major perioperative complications were recorded. VAS and ODI scores were demonstrated to exhibit a clinically and statistically significant ( p  < 0.05) amelioration in all patients' categories directly postoperatively, which was preserved until the end of follow-up. Overall outcomes according to modified MacNab criteria were excellent in 12 patients (57.1%), good in 6 (28.6%) and fair in 3 (14.3%) patients.

CONCLUSIONS: PTED is safe and effective in extreme cases of FS encountered in patients with ADS, previous posterior open decompression surgery and ASD after previous spinal fusion.