The relationship between preoperative predictive factors for clinical outcome in patients operated for lumbar spinal stenosis by decompressive laminectomy

INTRODUCTION

Lumbar spinal stenosis (LSS) can be effectively treated with decompressive laminectomy without fusion. Here, we asked what preoperative risk factors would contribute to poorer postoperative outcomes. Notably, the literature had previously shown that elevated preoperative body mass index (BMI) and a history of smoking both contributed to poorer outcomes following decompressive LSS surgery.[3,7,8]

MATERIALS AND METHODS

This study included 65 patients averaging 70.4 years of age with LSS undergoing decompressive laminectomy without fusion. There were 36 males (56%) and 29 females (44%). All patients failed conservative treatment for at least 6 months before undergoing LSS surgery. Those with a diagnosis of spondylolisthesis, spinal tumors, infections, or prior surgery were excluded from this analysis. The following preoperative parameters were assessed to determine their impact on surgical outcomes: gender, age, BMI, smoking history, use of pain/antidepressant/anxiolytic medications, and preoperative neurological deficit/disability level. The latter was estimated utilizing the Oswestry Disability Index (ODI) score, evaluated preoperatively and 1, 6, and 12 months postoperatively (follow-up) [Table 1].

Table 1:: Clinical characteristics of patients.

RESULTS

There was a statistically significant improvement in ODI values for all patients. The multivariate analysis revealed that patients with high preoperative BMI had significantly lesser postoperative ODI at 1 postoperative year (e.g., poor outcomes). After surgery, 44 patients (67%) reduced the use of anxiolytic drugs, 52 patients (80%) used fewer antidepressants, and 33 patients (50%) took fewer pain medications. Other factors such as age and gender were not statistically significant [Table 2].

Table 2:: Multiple linear regression model predicting the change in disability during follow-up.

DISCUSSION

Some authors showed equivalent clinical outcomes for those with elevated preoperative BMI and a history of smoking; alternatively, they attributed poorer postoperative results to increased perioperative blood loss and more chronic preoperative lumbar pain contributing to longer hospital length of stay.[6,9]

Other literature documented that both obesity and smoking contributed to greater perioperative risks/complications of laminectomy for LSS.[1,2,4,5,10,11] Here, we found that greater preoperative BMI alone contributed to poorer postoperative outcomes following lumbar laminectomy without fusion for LSS, largely attributed to protracted postoperative bed rest, and more difficulty with rehabilitation. The authors, therefore, concluded that preoperative diet and exercise programs, by reducing preoperative BMI, would enhance future recovery from laminectomy for LSS.

CONCLUSION

Decompressive laminectomy to treat lumbar spinal stenosis was effective to treat pain and disability. In this prospective study baseline elevated BMI was statistically associated with postoperative poor results in terms of ODI value.