Open And Minimally Invasive Technologies In Surgical Treatment Of Stable Symptomatic Stenosis Of The Lumbar Spine

The traditional open surgical interventions for symptomatic stenosis (though providing sufficient decompression and stable fixation) have a number of drawbacks. Therefore, today an increasing number of surgeons prefer minimally invasive decompression and fusion. As any new methodology, the process of learning is accompanied with difficulties in assessing the degree of decompression, and also with an increasing risk of intraoperative complications.The aim of the study was to compare the early and long-term outcomes of the traditional and novel minimally invasive techniques in patients with symptomatic lumbar stenosis without instability of the operated segments, while considering the patient quality of life and satisfaction with the treatment.Materials and Methods. This ambispective cohort study included 204 patients with symptoms of degenerative stenosis of the lumbar spine; the patients underwent either open (group 1; n=114) or minimally invasive (group 2; n=90) surgeries on one or two spinal segments. In group 1, classical laminectomy/interlaminectomy (29.8%) was performed in combination with posterolateral (5.3%), transforaminal fusion (60.5%) or interspinous stabilization (4.4%). In group 2, we used percutaneous bilateral pedicle osteotomy and lengthening (21.1%), intralaminar tubular decompression (73.3%), and transforaminal fusion (5.6%).The minimum postoperative follow-up was 24 months.Results. In both groups, the limited decompression with foraminotomy prevailed. Minimally invasive procedures were accompanied by a lower intraoperative blood loss and a shorter hospital stay (p<0.000001). There were no statistically significant differences in the incidence of intraoperative complications.Compared to the preoperative period, the pain syndrome significantly decreased in both groups, and the quality of life improved and remained at the improved level (p<0.05, Wilcoxon's test) throughout the entire observation period.The long-term results of the treatment (after 2 years) showed no superiority in the open surgery methods. According to the physical health parameters (SF-12), the Oswestry disability index (ODI), and the low back pain score (VAS), the quality of life in patients operated with the minimally invasive technologies was higher (p<0.03). About 54 and 41% of patients in group 1, as well as 67 and 26% of patients in group 2, were completely and partially (respectively) satisfied with the results of surgical treatment. In group 2, there were a greater number of patients with excellent results (by the MacNab scale), 1 and 2 years after surgery (18.8 vs. 6.1% and 34.4 vs. 14.9%, respectively). During the first year of observation, unsatisfactory results were more often observed in group 1 (p<0.016); after 2 years, the similarly unsatisfactory results developed more often in group 2 (p<0.0077).Conclusion. With stable 1-2 levels symptomatic lumbar stenosis, the use of a minimally invasive decompression technology is justified; with unstable stenosis, the minimally invasive spinal fusion can be recommended. Percutaneous osteotomy and lengthening of pedicles, as well as tubular intralaminar micro-decompression, are appropriate alternatives in the presence of mild symptomatic stenosis with/without severe comorbidity.