Dural lesions in decompression for lumbar spinal stenosis: incidence, risk factors and effect on outcome

INTRODUCTION: Decompression for lumbar spinal stenosis is one of the most frequent operations on the spine today. The most common complication seems to be a peroperative dural lesion. There are few prospective studies on this complication regarding incidence and effect on long-term outcome; this is the background for the current study. MATERIALS AND METHODS: Swespine, the Swedish Spine Register documents the majority (>80%) of lumbar spine operations in Sweden today. Within the framework of this register, totally 3,699 operations for spinal stenosis during a 5-year period were studied regarding complications and 1-year postoperative outcome. Mean patient age was 66 (37-92) years and 44% were males. Fourteen percent were smokers and 19% had undergone previous lumbar spine surgery. RESULTS: The overall incidence of a peroperative dural lesion was 7.4%, 8.5% of patients undergoing decompressive surgery only and 5.5% of patients undergoing decompressive surgery + fusion (p < 0.001). A logistic regression analysis demonstrated that (high) age (p < 0.0004), previous surgery (p < 0.036) and smoking (p < 0.049) were significantly predictive factors for dural lesions. An odds ratio estimate demonstrated an age-related risk increase with 2.7% per year. The risk for dural lesions also increased with number of levels decompressed. The 1-year outcome was identical in the two groups with and without a dural lesion. CONCLUSION: A dural lesion was seen in 7.4% of decompressive operations for spinal stenosis. High age, previous surgery and smoking were risk factors for sustaining a lesion, which, however, did not affect the 1-year outcome negatively.