Surgical Recovery for Patients with Concomitant Hypertension and Lumbar Spinal Stenosis

• Author / Creator

  Roop, Sanjesh C

• Introduction: Lumbar Spinal Stenosis (LSS) is a prevalent musculoskeletal condition affecting 8-11% of the United States general population. LSS is the most common reason requiring lumbar spine surgery in adults older than 65 years, with an adjusted rate of 135.5 low back surgeries per 100,000 Medicare beneficiaries. The onset of symptoms typically begins at 50 years of age and often results in localized and radiating leg pain, which limit activities such as walking. Patients with confirmed LSS may be candidates for surgery if conservative treatments have failed to manage symptoms. Patients who received surgery for LSS compared to conservative treatment experience greater improvement in pain relief, function, patient satisfaction and self-report recovery up to 4 years after treatment. The prognostic factors of poor post-operative functional outcome included: depression, cardiovascular comorbidity, disorder influencing walking ability, and scoliosis. High blood pressure (HBP) is reported in 23.2-48.3% of patients with LSS and is associated with lower health status. It is unclear whether HBP affects LSS surgical outcomes. Objective: The primary objective of this cohort study was to evaluate whether HBP was associated with poor recovery following LSS-related surgery. The secondary objectives are (1) to identify the rate of pre-surgical HBP in this community-based LSS cohort, (2) to determine whether the rate or type of post-surgical complications differ between participants with and without HBP, and (3) to describe functional recovery after surgery for LSS. Methods: Patients were identified as study candidates at the time of magnetic resonance imaging in Calgary, Alberta between April 2004 and May 2005. After implementing the study inclusion and exclusion criteria, the cohort comprised 97 participants who received spinal surgery for LSS and were followed over 2 years. Disability status was assessed pre-and post-operatively using the Oswestry Disability Index (ODI), a disease-specific questionnaire. HBP was identified by self-report, anti-hypertensive medication use, and/or diagnosis of HBP prior to surgery using Alberta Health (AH) data. Participants were interviewed before surgery and within 2 years after surgery. A multiple linear regression model was used to assess HBP as a prognostic factor for post-operative disability status. Potential confounders were included in the model to control for the effect of HBP on post-operative ODI. Results: Of the 97 participants who had back surgery, 46 were surgical participants identified by self-report alone and 25 by AH data alone, and 26 participants who were identified by both sources. The study cohort had a mean age of 71.8 (SD 12.9) years, 52% were women, and the mean number of comorbidities was 2.3 (SD 1.9). The mean ODI score was 59.0 (SD 17.0) pre-operatively and 30.1 (SD 17.7) post-operatively. Forty-nine (50.5%) participants were hypertensive. Regardless of blood pressure status, large gains in function were seen up to 2 years after surgery for LSS (effect size: 1.73; 95% CI: 1.39, 2.06). Of the 51 participants with available surgical data, 20 (39.2%) participants experienced at least one post-surgical complication, and had a median length of hospital stay of 5.0 (IQR 3.0-8.0) days. Comparing participants with and without HBP, baseline group differences were not seen for gender, follow-up time, pre-operative ODI score, or depression. No group differences were seen post-operatively on the ODI comparing the HBP group (mean 30.1, SD 17.7) and the non-HBP group (mean 28.7, SD 17.1, p=0.699). After controlling for age, gender, follow-up time, pre-operative ODI, number of comorbidities and depression, the post-operative ODI score was 1.32 units higher for participants with pre-existing HBP compared to those without HBP (95% CI: -5.64, 8.28, p= 0.747). The standardized coefficient revealed that a 1-point increase in pre-operative ODI score was associated with a 0.38-point increase in ODI post score (95% CI: 0.16, 0.60). Conclusion: Although earlier work suggested that hypertensive patients with LSS have lower scores for overall health-related quality of life than those without HBP, hypertension does not appear to have a deleterious effect on functional recovery after LSS-related surgery. Consistent with the findings from other research, our study cohort experienced large gains in functional recovery and symptom reduction up to 2 years after surgery regardless of HBP. For patients whose conservative management fails to relieve symptoms and are concerned about undergoing LSS-related surgery, our findings show that participants were likely to see improvements in disability status.

• Subjects / Keywords

  • Lumbar
  • Spine
  • Surgery
  • Disability
  • ODI
  • Hypertension
  • Stenosis

• Graduation date

  Spring 2016

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3QZ22T87

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.