Abstract
Introduction
Surgical decompression is the gold standard in the treatment of symptomatic lumbar spinal canal stenosis (LSCS) without clinically significant instability. With the advent of microsurgical techniques and better accessories such as the tubular retractor system (TRS), unilateral approach bilateral decompression (UABD) has been advocated as the decompressive technique of choice because of the preservation of anatomically important stabilizing structures. This retrospective study evaluates the midterm results of UABD performed with and without the TRS in a regional hospital.
Patients and Methods
From April 2008 till November 2013, 89 patients with symptomatic LSCS without clinical instability had UABD performed. On the basis of the surgeons' preference, 56 cases were operated with the TRS employed. The mean follow-up was 30.8 months. Clinical outcomes were evaluated by the Visual Analogue Scale (VAS), Japanese Orthopaedic Association lumbar spine score (JOA score), Oswestry Disability Index (ODI), and Roland Morris Disability Quotient (RMDQ). Complications, rate of reoperation, and patient's subjective satisfaction were also evaluated.
Results
A total of 150 levels were decompressed (average, 1.7 levels per patient). The average operation time and blood loss per level was 99.4 minutes and 67.9 mL, respectively. The mean postoperative hospital stay was 4.5 days. The average leg VAS, JOA score, ODI, and RMDQ improved from 7.1, 15.5, 48.3% and 13.1 to 3.3, 22.1, 35.4% and 11.5, respectively, at final follow-up. The subjective satisfaction was 64%. Given the choice, 92% of these patients would choose to have the same procedure again. There were no statistical significant difference between the TRS and no TRS group in age; sex; side of approach; the preoperative, postoperative, and improvement in leg VAS, JOA score, ODI, and RMDQ; follow-up duration; operation time; and subjective satisfaction. Blood loss (67 vs. 178.4 mL, p = 0.09) and postoperation hospital stay (3.9 vs. 5.7 days, p = 0.003) were both in favor of the TRS. Overall, five incidental durotomies in the TRS group (8.9%) and 3 (9%) in non-TRS group were registered, giving rise to a total 9% of the incidental durotomy rate. All of these eight cases were treated conservatively and none of them needed any further procedures as a remedy. Otherwise, no remarkable perioperative morbidities had been recorded. Within the evaluation period, two cases from the TRS group need re-decompression with instrumented fusion because of symptomatic recurrence, equivalent to an overall 2.2% reoperation rate.
Conclusion
Microsurgical UABD generates satisfactory clinical outcomes in selected patients with symptomatic LSCS without clinical instability. No apparent clinical benefit was found in employing the TRS other than an average 1.8 day short postoperative hospital stay.