Does daily tobacco smoking affect outcomes after microdecompression for degenerative central lumbar spinal stenosis? - A multicenter observational registry-based study

There are limited scientific data on the impact of smoking on patient-reported outcomes following minimally invasive spine surgery. The aim of this multicenter observational study was to examine the relationship between daily smoking and patient-reported outcome at 1 year using the Oswestry Disability Index (ODI) after microdecompression for single- and two-level central lumbar spinal stenosis (LSS). Secondary outcomes were the length of hospital stays, perioperative and postoperative complications.Data were collected through the Norwegian Registry for Spine Surgery (NORspine).A total of 825 patients were included (619 nonsmokers and 206 smokers). For the whole patient population there was a significant difference between preoperative ODI and ODI at 1 year (17.3 points, 95% CI 15.93-18.67, p 0.001). There was a significant difference in ODI change at 1 year between nonsmokers and smokers (4.2 points, 95% CI 0.98-7.34, p = 0.010). At 1 year 69.6% of nonsmokers had achieved a minimal clinically important difference (≥10 points ODI improvement) compared to 60.8% of smokers (p = 0.008). There was no difference between nonsmokers and smokers in the overall complication rate (11.6% vs. 9.2%, p = 0.34). There was no difference between nonsmokers and smokers in length of hospital stays for either single-level (2.3 vs. 2.2 days, p = 0.99) or two-level (3.1 vs. 2.3 days, p = 0.175) microdecompression. Smoking was identified as a negative predictor for ODI change in a multiple regression analysis (p = 0.001) CONCLUSIONS: Nonsmokers experienced a significantly larger improvement at 1 year following microdecompression for LSS compared to smokers. Smokers were less likely to achieve a minimal clinically important difference. However, it should be emphasized that considerable improvement also was found among smokers.