Patient-Reported Outcomes and Reoperation Rates Following Lumbar Tubular Microdecompression: Six-year Follow-Up

Study Design.Prospective cohort study Objective.To report reoperation rates after lumbar tubular microdecompression (LTM) and to compare patient-reported outcomes (PROs) six years after surgery between those who did and did not need revision at the index level. Summary of Background Data.Long-term data describing PROs and reoperation rates after LTMs are lacking. Materials and Methods.Patients with lumbar spinal stenosis underwent one or more of three LTM procedures. Demographic, PROs [Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain], and reoperation data were collected. Failure of an index LTM was defined as any revision surgery at the index level. Revision LTM at a different level was not considered failure. Failure and revision LTM incidence at a different level and cumulative incidence were prospectively collected up to six years. Mixed effects linear regressions with 95% CIs were performed to assess potential differences in ODI and reported VAS back and leg pain between patients that reported failure and those that did not. Results.A total of 418 patients were included with median follow-up of 3.0 (1.9, 4.1) years. In all, 25% had a reoperation by six years. Sixty-five (16%) failed and 35 (9%) underwent a second LTM at another level. Cumulative failure incidence was 9% within the first two years. Failure patients had a statistically higher ODI [12.1 (95% CI, 3.2, 20.1) and VAS back [2.3 (95% CI, 0.9, 3.8)] and leg pain [1.6 (95% CI, 0.2, 3.1)] throughout follow-up. The overall dural tear rate was 7.2%. Conclusions.LTM is an effective treatment for lumbar spinal stenosis with sustained six-year PROs. Most failures occur within two years postoperatively and stabilize to 4% yearly incidence by year 5. The yearly incidence of reoperation with LTM stabilizes at 3% by year 6 postoperatively.