Minimally invasive lumbar disectomy with the tubular retractor system: 4-7 years follow-up.

BACKGROUND: Herniated nucleus pulposus (HNP) is a common cause of low back pain. The conventional technique could injure to the surrounding structures. The tubular retractor system (METRx-X tube, Medtronic, Inc, Minneapolis, USA) is instrument to improve visualization and limited soft tissue damage for minimal invasive lumbar discetomy. OBJECTIVE: To evaluate the surgical outcomes, complications, reoperation rates and patient satisfaction for using tubular retractor system in lumbar disectomy in long term follow-up at least 4 years. MATERIAL AND METHOD: Forty-five patients who had been operated for lumbar microdisectomy with tubular retractor system between Jan 2004-Dec 2007. Demographic data, ODI, VAS scores of back pain and leg pain were collected at the date of admission, 1st week, 1st month, 3rd month and every 6 months until 48 months follow-up. RESULTS: Forty-two patients (26 males with average age 30.4; range 20-45 years, 16 females with average age 32.6; range 23-54 years) were included in the present study by excluding 3 loss follow-up patients. The average operating time with tubular retractor system was 90.5 (range 60-250) minutes.Average blood loss was about 45 (range 30-100) milliliters. Length of stay in the present study was about 4.6 days (2-10 days). The average size of incision was about 2.4 (range 2.0-3.5) centimeters. The average follow-up time of all cases was 4 years 7 months (4-7 years). The VAS score of back pain was significantly improved at 1st month post-operation (p < or = 0.05). The VAS score of leg pain was significantly improved at 1st week post-operation (p < or = 0.05). The ODI score was significantly improved at 1st month post-operation (p < or = 0.05). The complication rate was about 9.5% (4 patients) and the recurrent disc that need to re-operation rate was about 4.9% (2 patients). CONCLUSION: The tubular retractor system has the advantage over the conventional open technique. The result of operation with the tubular retractor was satisfied by the surgeons and the patients. However, This system is quite expensive and need technological equipment. Besides experience of the surgeons, using tubular retractor system also should be carefully considered for the most benefit to the patients, the surgeons and budgets of the institute.