Abstracts of the 2013 Annual Meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves
Phoenix, Arizona • March 6–9, 2013
Michael P. Kelly, Lukas P. Zebala, Han Jo Kim, Daniel M. Sciubba, Justin S. Smith, Christopher I. Shaffrey, Shay Bess, Eric Klineberg, Gregory Mundis Jr., Douglas Burton, Robert Hart, Alex Soroceanu, Frank Schwab, Virginie Lafage, and International Spine Study Group
The goal of this study was to examine the effectiveness of preoperative autologous blood donation (PABD) in adult spinal deformity (ASD) surgery.
Patients undergoing single-stay ASD reconstructions were identified in a multicenter database. Patients were divided into groups according to PABD (either PABD or NoPABD). Propensity weighting was used to create matched cohorts of PABD and NoPABD patients. Allogeneic (ALLO) exposure, autologous (AUTO) wastage (unused AUTO), and complication rates were compared between groups.
Four hundred twenty-eight patients were identified as meeting eligibility criteria. Sixty patients were treated with PABD, of whom 50 were matched to 50 patients who were not treated with PABD (NoPABD). Nearly one-third of patients in the PABD group (18/60, 30%) did not receive any autologous transfusion and donated blood was wasted. In 6 of these cases (6/60, 10%), patients received ALLO blood transfusions without AUTO. In 9 cases (9/60, 15%), patients received ALLO and AUTO blood transfusions. Overall rates of transfusion of any type were similar between groups (PABD 70% [42/60], NoPABD 75% [275/368], p = 0.438). Major and minor in-hospital complications were similar between groups (Major PABD 10% [6/60], NoPABD 12% [43/368], p = 0.537; Minor PABD 30% [18/60], NoPABD 24% [87/368], p = 0.499). When controlling for potential confounders, PABD patients were more likely to receive some transfusion (OR 15.1, 95% CI 2.1-106.7). No relationship between PABD and ALLO blood exposure was observed, however, refuting the concept that PABD is protective against ALLO blood exposure. In the matched cohorts, PABD patients were more likely to sustain a major perioperative cardiac complication (PABD 8/50 [16%], NoPABD 1/50 [2%], p = 0.046). No differences in rates of infection or wound-healing complications were observed between cohorts.
Preoperative autologous blood donation was associated with a higher probability of perioperative transfusions of any type in patients with ASD. No protective effect of PABD against ALLO blood exposure was observed, and no risk of perioperative infectious complications was observed in patients exposed to ALLO blood only. The benefit of PABD in patients with ASD remains undefined.
Justin K. Scheer, Justin S. Smith, Frank Schwab, Virginie Lafage, Christopher I. Shaffrey, Shay Bess, Alan H. Daniels, Robert A. Hart, Themistocles S. Protopsaltis, Gregory M. Mundis Jr., Daniel M. Sciubba, Tamir Ailon, Douglas C. Burton, Eric Klineberg, Christopher P. Ames, and The International Spine Study Group
The operative management of patients with adult spinal deformity (ASD) has a high complication rate and it remains unknown whether baseline patient characteristics and surgical variables can predict early complications (intraoperative and perioperative [within 6 weeks]). The development of an accurate preoperative predictive model can aid in patient counseling, shared decision making, and improved surgical planning. The purpose of this study was to develop a model based on baseline demographic, radiographic, and surgical factors that can predict if patients will sustain an intraoperative or perioperative major complication.
This study was a retrospective analysis of a prospective, multicenter ASD database. The inclusion criteria were age ≥ 18 years and the presence of ASD. In total, 45 variables were used in the initial training of the model including demographic data, comorbidities, modifiable surgical variables, baseline health-related quality of life, and coronal and sagittal radiographic parameters. Patients were grouped as either having at least 1 major intraoperative or perioperative complication (COMP group) or not (NOCOMP group). An ensemble of decision trees was constructed utilizing the C5.0 algorithm with 5 different bootstrapped models. Internal validation was accomplished via a 70/30 data split for training and testing each model, respectively. Overall accuracy, the area under the receiver operating characteristic (AUROC) curve, and predictor importance were calculated.
Five hundred fifty-seven patients were included: 409 (73.4%) in the NOCOMP group, and 148 (26.6%) in the COMP group. The overall model accuracy was 87.6% correct with an AUROC curve of 0.89 indicating a very good model fit. Twenty variables were determined to be the top predictors (importance ≥ 0.90 as determined by the model) and included (in decreasing importance): age, leg pain, Oswestry Disability Index, number of decompression levels, number of interbody fusion levels, Physical Component Summary of the SF-36, Scoliosis Research Society (SRS)–Schwab coronal curve type, Charlson Comorbidity Index, SRS activity, T-1 pelvic angle, American Society of Anesthesiologists grade, presence of osteoporosis, pelvic tilt, sagittal vertical axis, primary versus revision surgery, SRS pain, SRS total, use of bone morphogenetic protein, use of iliac crest graft, and pelvic incidence–lumbar lordosis mismatch.
A successful model (87% accuracy, 0.89 AUROC curve) was built predicting major intraoperative or perioperative complications following ASD surgery. This model can provide the foundation toward improved education and point-of-care decision making for patients undergoing ASD surgery.
Micheal Raad, Brian J. Neuman, Amit Jain, Hamid Hassanzadeh, Peter G. Passias, Eric Klineberg, Gregory M. Mundis Jr., Themistocles S. Protopsaltis, Emily K. Miller, Justin S. Smith, Virginie Lafage, D. Kojo Hamilton, Shay Bess, Khaled M. Kebaish, Daniel M. Sciubba, and the International Spine Study Group
Given the recent shift in health care toward quality reporting requirements and a greater emphasis on a cost-quality approach, patient stratification with respect to long-term outcomes and the use of health care resources is of increasing value. Stratification tools may be effective if they are simple and evidence based. The authors hypothesize that preoperative patient-reported activity levels might independently predict postoperative outcomes in patients with adult spinal deformity.
This is a retrospective cohort. A total of 575 patients in a prospective adult spinal deformity surgical database were identified with complete data regarding the preoperative level of activity. Answers to question 5 of the Scoliosis Research Society-22r Patient Questionnaire (SRS-22r) were used to stratify patients into active and inactive groups. Outcomes were length of hospital stay (LOS), level of activity, and reaching the minimum clinically important difference (MCID) for SRS-22r domains and the Physical Component Summary (PCS) of the SF-36 at 2 years postoperatively. The 2 groups were compared with respect to several potential confounders. Covariates with p < 0.1 were controlled for. The impact of activity on LOS was assessed using multivariate negative binomial regression analysis. Multivariate logistic regression models additionally controlling for the respective baseline health-related quality of life (HRQOL) scores were used to assess the association between preoperative activity levels and reaching the MCID at 2 years postoperatively.
A total of 420 (73%) of the 575 patients who met the inclusion criteria had complete data at 2 years postoperatively. The inactive group was more likely to be significantly older, have a higher Charlson Comorbidity Index, worse baseline radiographic deformity, and greater correction of most radiographic parameters. After controlling for possible confounders, the active group had a significantly shorter LOS (incidence risk ratio 0.91, p = 0.043). After adding respective baseline HRQOL scores to the models, active patients were significantly more likely to reach the MCID for the SRS-22r pain domain (OR 1.72, p = 0.026) and PCS (OR 1.94, p = 0.013). Active patients were also significantly more likely to be active at 2 years postoperatively on multivariate analysis (OR 8.94, p < 0.001).
The authors’ results show that patients who belong to the inactive group are likely to have a longer LOS and lower odds of reaching the MCID in HRQOL or being active at 2 years postoperatively. Inquiring about patients’ preoperative activity levels might be a reliable and simple stratification tool in terms of long- and short-term outcomes in ASD patients.