Microdiscectomy for lumbosacral disc herniation and frequency of failed disc surgery

Abstract

Background: Microdiscectomy for lumbosacral disc herniations is one of the most commonly performed neurosurgical procedures. The patient demographics, symptomatology, and recovery are highly variable, and surgical outcomes depend on several factors, including patient demographics. Failed disc surgery refers to failure of improvement in patient's symptoms following microdiscectomy, and has been observed to occur in up to 12% of patients. To date, no study form Pakistan has looked into patient demographics and failed disc surgery rates within the local context.

Objective: The aim of this study was to review the demographics of the patient population presenting for surgical treatment of lumbosacral disc herniations and to review our results of lumbosacral microdiscectomy at a university hospital in Pakistan.

Methods: This is a retrospective analysis of all adult patients admitted from January 2003 to January 2008 for symptomatic lumbosacral disc herniation requiring microdiscectomy, at the Aga Khan University Hospital, Karachi. Data were collected through our medical records, on a standardized form. Basic information about the patient population, disease process, modes of nonsurgical treatment, and details on surgery and postoperative course were recorded and analyzed using SPSS.

Results: Five hundred one patients were studied, based on inclusion criteria. The mean age was 41.2 years; 347 (69%) patients were male and 154 (31%) female. Mean body mass index of the population was 26 and was higher in females. All patients primarily presented with radiculopathy, and the mean duration of these symptoms was 438 days. Mean duration of nonoperative management was 53 weeks. Fifty-one patients (10.2%) had previously undergone spine surgery. A total of 442 (88%) patients were operated at single disc level, and the rest at two levels. Sixty-six (13%) patients were operated for upper lumbar disc herniations. Mean operative time was 94 minutes, and the most common complication was dural tear. Mean length of hospital stay was 5 days (2-12 days). Mean follow-up was 48.3 weeks (4 weeks to 14 years). Complete resolution of symptoms was seen in 360 (71.9%) patients and failed disc surgery was diagnosed in 42 (8.4%) patients. Twenty-six patients (5.2%) were reoperated upon, with gradual improvement. The authors report an overall failed back surgery rate of 8.38%.

Conclusions: Overall our results were comparable to published international literature. However, the authors observed significant differences in demographics, especially in terms of age, gender distribution, and mean BMI of patient population as well as frequency of involvement of upper lumbar discs.