Microendoscopic discectomy (MED) for lumbar disc herniation: comparison of learning curve of the surgery and outcome with other established case studies.

Background: To compare the results of a series of microendoscopic discectomies done at a government medical college in South India, with other published series and to analyze the learning curve for the procedure.

Methods: Microendoscopic discectomy (MED) was performed in 40 patients. The cases were in the age group between 20-50 years (mean age, 32.3 years). The period of study was 3 years. The most common level operated was L5-S1 (27 cases) followed by L4-L5 (12 cases). Double level disc herniation was observed in 1 patient, at L4-L5 and L5-S1. Patients with bilateral involvement and lumbar stenosis were excluded from the study. Diagnosis was based on clinical neurological examination, X-ray, CT and MRI. The MED was performed, following Destandau's procedure using Storz endoscopic microdiscectomy system. All patients were followed up regularly on 10 postoperative day, 1 month, 3 months and 1 year. Mean follow up of all patients were 14.1 months. The learning curve for the procedure was also analyzed.

Results: In our case series comprising of 40 cases, it was observed that as compared to other established studies, the mean operative duration, intraoperative blood loss, mean hospital stay and complication rate was largely reduced, with good experience and training. The outcome based upon modified Macnab criteria, showed that in maximum number of patients had excellent outcome and only 3 out of the 40 cases had poor outcome. Moreover, since the procedure was technically demanding, it took initial 20 cases to complete our learning curve and in the next 20 cases it was observed that we had improved our technique, operating time, blood loss, and outcome.

Conclusions: MED in properly trained hands is an excellent technique that could replace the conventional open surgery, in the management of lumbar disc disease if the learning curve could be overcome.