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 (a parts per thousand yen10 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) 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.