Neil Manson

Predictors of Blood Transfusion in Posterior Lumbar Spinal Fusion: A Canadian Spine Outcome and Research Network Study

Study Design. Retrospective cohort study. Objective. To identify patient or procedure related predictors of postoperative blood transfusions in posterior lumbar fusion (PSF). Summary of Background Data. The rate of PSF surgery has increased significantly. It remains the most common surgical procedure used to stabilize the spine; however, the impact of blood loss requiring blood transfusions remains a significant concern. Methods. Analysis of data from the Canadian Spine Outcomes and Research Network. Patients who underwent PSF between 2008 and 2015 were identified. Multivariate analysis was used to identify predictors of blood transfusion from the collected information. Results. Seven hundred seventy two patients have undergone PSF, 18% required blood transfusion, 54.8% were females and the mean age was 60 years. The analysis revealed five significant predictors: American Society of Anesthesiologist class (ASA), operative time, multilevel fusion, sacrum involvement, and open posterior approach. The odds of transfusion for those with ASA >1 were 6 times those with ASA1 (odds ratio [OR] 6.1, 95% confidence interval [CI] 1.4–27.1, P < 0.018). For each 60-minute increase in operative time, the odds of transfusion increased by 4.2% (OR 1.007, 95% CI 1.004–1.009, P < 0.001). The odds of transfusion were 6 times higher for multilevel fusion (OR 5.8, 95% CI 2.6–13.2, P < 0.001). Extending fusion to the sacrum showed 3 times higher odds for blood transfusion (OR 3.2, 95% CI 1.8–5.8, P < 0.001). The odds of transfusion for patients undergoing open approach were 12 times those who had minimal invasive surgery (OR 12.5, 95% CI 1.6–97.4, P < 0.016). Finally, patients receiving transfusions were more likely to have extended hospital stay. Conclusion. ASA >1, prolonged operative time, multilevel fusion, sacrum involvement, and open posterior approach were significant predictors of blood transfusion in PSF. Level of Evidence: 3

The Incidence of Adjacent Segment Breakdown in Polysegmental Thoracolumbar Fusions of Three or More Levels with Minimum 5-Year Follow-up.

Study Design Retrospective cohort study. Objective To identify the incidence of adjacent segment pathology (ASP) after thoracolumbar fusion of three or more levels, the risk factors for the development of ASP, and the need for further surgical intervention in this particular patient population. Methods A retrospective analysis of a prospective surgical database identified 217 patients receiving polysegmental (≥ 3 levels) spinal fusion with minimum 5-year follow-up. Risk factors were evaluated, and the following data were obtained from the review of radiographs and charts: radiographic measures—levels fused, fusion status, presence of ASP; clinical measures—patient assessment, Oswestry Disability Index (ODI), and the need for further surgery. Results The incidence of radiographic ASP (RASP) was 29%; clinical or symptomatic ASP (CASP), 18%; and those requiring surgery, 9%. Correlation was observed between ODI and ASP, symptomatic ASP, and need for revision surgery. Age, preoperative degenerative diagnosis, and absence of fusion demonstrated significant association to ASP. Conclusions ASP was observed in a significant number of patients receiving polysegmental fusion of three or more levels. ODI scores correlated to RASP, CASP, and the need for revision surgery.

Elevated Patient Body Mass Index Does Not Negatively Affect Self-Reported Outcomes of Thoracolumbar Surgery: Results of a Comparative Observational Study with Minimum 1-Year Follow-Up

Study Design Retrospective study. Objective Quantify the effect of obesity on elective thoracolumbar spine surgery patients. Methods Five hundred consecutive adult patients undergoing thoracolumbar spine surgery to treat degenerative pathologies with minimum follow-up of at least 1 year were included. Primary outcome measures included Numerical Rating Scales for back and leg pain, the Short Form 36 Physical Component Summary and Mental Component Summary, the modified Oswestry Disability Index, and patient satisfaction scores collected preoperatively and at 3, 6, 12, and 24 months postoperatively. Secondary outcome measures included perioperative and postoperative adverse events, postoperative emergency department presentation, hospital readmission, and revision surgeries. Patients were grouped according to World Health Organization body mass index (BMI) guidelines to isolate the effect of obesity on primary and secondary outcome measures. Results Mean BMI was 30 kg/m2, reflecting a significantly overweight population. Each BMI group reported statistically significant improvement on all self-reported outcome measures. Contrary to our hypothesis, however, there was no association between BMI group and primary outcome measures. Patients with BMI of 35 to 39.99 visited the emergency department with complaints of pain significantly more often than the other groups. Otherwise, we did not detect any differences in the secondary outcome measures between BMI groups. Conclusions Patients of all levels of obesity experienced significant improvement following elective thoracolumbar spine surgery. These outcomes were achieved without increased risk of postoperative complications such as infection and reoperation. A risk–benefit algorithm to assist with surgical decision making for obese patients would be valuable to surgeons and patients alike.

Patient Reported Outcomes Following Surgery for Degenerative Spondylolitshtesis: Comparison of a Universal and Multi-Tier Health Care System

STUDY DESIGN Retrospective review of results from a prospectively collected Canadian cohort in comparison to published literature. OBJECTIVES (1) To investigate whether patients in a universal health care system have different outcomes than those in a multitier health care system in surgical management of degenerative spondylolisthesis (DS). (2) To identify independent factors predictive of outcome in surgical DS patients. SUMMARY OF BACKGROUND DATA Canada has a national health insurance program with unique properties. It is a single-payer system, coverage is universal, and access to specialist care requires referral by the primary care physician. The United States on the other hand is a multitier public/private payer system with more rapid access for insured patients to specialist care. METHODS Surgical DS patients treated between 2013 and 2016 in Canada were identified through the Canadian Spine Outcome Research Network (CSORN) database, a national registry that prospectively enrolls consecutive patients with spinal pathology from 16 tertiary care academic hospitals. This population was compared with the surgical DS arm of patients treated in the Spine Patients Outcome Research Trial (SPORT) study. We compared baseline demographics, spine-related, and health-related quality of life (HRQOL) outcomes at 3 months and 1 year. Multivariate analysis was used to identify factors predictive of outcome in surgical DS patients. RESULTS The CSORN cohort of 213 patients was compared with the SPORT cohort of 248 patients. Patients in the CSORN cohort were younger (mean age 60.1 vs. 65.2; p<.001), comprised fewer females (60.1% vs. 67.7%; p=.09), and had a higher proportion of smokers (23.3% vs. 8.9%; p<.001). The SPORT cohort had more patients receiving compensation (14.6% vs. 7.7%; p<.001). The CSORN cohort consisted of patients with slightly greater baseline disability (Oswestry disability index scores: 47.7 vs. 44.0; p=.008) and had more patients with symptom duration of greater than 6 months (93.7% vs. 62.1%; p<.001). The CSORN cohort showed greater satisfaction with surgical results at 3 months (91.1% vs. 66.1% somewhat or very satisfied; p<.01) and 1 year (88.2% vs. 71.0%, p<.01). Improvements in back and leg pain were similar comparing the two cohorts. On multivariate analysis, duration of symptoms, treatment group (CSORN vs. SPORT) or insurance type (public/Medicare/Medicaid vs. Private/Employer) predicted higher level of postoperative satisfaction. Baseline depression was also associated with worse Oswestry disability index at 1-year postoperative follow-up in both cohorts. CONCLUSIONS Surgical DS patients treated in Canada (CSORN cohort) reported higher levels of satisfaction than those treated in the United States (SPORT cohort) despite similar to slightly worse baseline HRQOL measures. Symptom duration and insurance type appeared to impact satisfaction levels. Improvements in other patient-reported health-related quality of life measures were similar between the cohorts.

Predictive Factors for Discharge Destination Following Posterior Lumbar Spinal Fusion: A Canadian Spine Outcome and Research Network (CSORN) Study

Study Design: Ambispective cohort study. Objective: Patients spend on average 3 to 7 days in hospital after lumbar fusion surgery. Patients who are unable to be discharged home may require a prolonged hospital stay while awaiting a bed at a rehabilitation facility, adding cost and imposing a considerable burden on the health care system. Our objective is to identify patient or procedure related predictors of discharge destination for patients undergoing posterior lumbar fusion. Methods: Analysis of data from the Canadian Spine Outcomes and Research Network. Patients who underwent lumbar fusion for degenerative pathology between 2008 and 2015 were identified. Multivariable logistic regression analysis was used to identify independent predictors of the discharge destination. Results: A total of 643 patients were identified from the database, 87.1% of the patients (N = 560) were discharged home while 12.9% (N = 83) required discharge to nonhome facilities. Using multivariate logistic regression analysis, the predictors for discharge to a facility rather than home were identified including: increasing age (odds ratio [OR] 1.045, 95% confidence interval [CI] 1.017 -1.075, P < .002), increasing body mass index (BMI) (OR 1.069, 95% CI 1.021 -1.118, P < .004), increasing disability score (OR 1.025, 95% CI 1.004 -1.046, P < .02), living alone preoperatively (OR 1.916, 95% CI 1.004-3.654, P < .05), increasing operating time (OR 1.005, 95% CI 1.003 -1.008, P < .0001), need for blood transfusion (OR 3.32, 95% CI 1.687-6.528, P < .001), and multilevel fusion surgery (OR 1.142, 95% CI 1.007 -1.297, P < .04). Conclusions: Older age, high BMI, living alone, high disability score, extended surgical time, blood transfusion, and multilevel fusion are significant factors that increase the odds of being discharged to facilities other than home. Level of Evidence: Level 3.

MASTERS-D: Final Results of a Prospective Multi-Center Observational Data-Monitored Study of Minimally Invasive Fusion to Treat Degenerative Lumbar Disorders

Introduction Evaluation of 1- or 2-level minimally invasive posterior lumbar interbody fusion (MILIF) for degenerative lumbar (DL) disorders in a multicenter 1-year prospective observational study (NCT01143324). Material and Methods A total of 252 patients (56% female patients, mean age: 54 years, mean BMI: 28, mean duration of symptoms: 29 months [m]) enrolled by 19 centers in 14 countries underwent 1- (83%) or 2-level (17%) MILIF (TLIF: 95%; PLIF: 5%) for treatment of leg pain (52%), back pain (39%), or claudication (9%) due to DL pathologies, including spondylolisthesis (53%), stenosis (71%), and/or disc pathology (94%). Participating surgeons were required to have a minimum prestudy experience of 30 MILIF cases. A total of 15.1% of patients had previous decompression surgery at the target level. Patient demographics, intraoperative data, complications, time to first ambulation, time to study-defined recovery, surgical duration, blood loss, fluoroscopy time, and adverse events (AEs) were recorded. Outcome scores (VAS back and leg, ODI, EQ-5D) were assessed preoperatively and at defined time points through 12 m postoperatively. Results Available for the follow-up: 249 (99%) patients at 4 weeks (w) and 233 (92.5%) at 12 m. One-level surgery occurred at L4–5 or L5–S1 in 91% and 2-level surgery at L4–S1 in 74%. Mean surgical duration, blood loss, and intraoperative fluoro-time were 128 versus 182 minutes, 164 versus 233 mL, and 115 versus 154 seconds in 1- and 2-level cases, respectively. The mean time to first ambulation was 1.3 days and time to study-defined recovery was 3.2 days. Mean preoperative VAS back (6.2) and VAS leg (5.9) scores dropped significantly (p < .0001) to 3.1 (2.9) and 1.9 (2.5) at discharge (4 w), respectively. VAS improvement was sustained between 4 w and final follow-up at 12 m. Fusion rates: 90.8% fusion in 1- and 90.7% for 2-level procedures (141 and 27 patients evaluated, respectively). Preoperative ODI (45.5%) and EQ-VAS (52.9) changed to 34.5% (22.4%) and 65.4 (71.0) at 4 w (12 m) (p < 0.0001). There was a constant improvement in EQ-5D subscales and reduction of pain medication from 4 w to 12 m. A total of 50 AEs in 39 patients (15.5%) were attributed to surgery, approach, or device (including 9 AEs in 8 patients), out of which 3 AEs in 3 patients (1.2%) were due to the minimally invasive approach (including 1 SAE); no deep surgical site infections and 7 reoperations occurred. Conclusion This is the largest data-monitored prospective multicenter observational study of MILIF to date, following routine local standard of practice and providing objective results for this procedure. MILIF demonstrated favorable clinical results with early and sustained improvement in patient-reported outcomes and low major perioperative morbidity.