Jeff Ehresman, Zach Pennington, Aditya V. Karhade, Sakibul Huq, Ravi Medikonda, Andrew Schilling, James Feghali, Andrew Hersh, A. Karim Ahmed, Ethan Cottrill, Daniel Lubelski, Erick M. Westbroek, Joseph H. Schwab and Daniel M. Sciubba
Incidental durotomy is a common complication of elective lumbar spine surgery seen in up to 11% of cases. Prior studies have suggested patient age and body habitus along with a history of prior surgery as being associated with an increased risk of dural tear. To date, no calculator has been developed for quantifying risk. Here, the authors’ aim was to identify independent predictors of incidental durotomy, present a novel predictive calculator, and externally validate a novel method to identify incidental durotomies using natural language processing (NLP).
The authors retrospectively reviewed all patients who underwent elective lumbar spine procedures at a tertiary academic hospital for degenerative pathologies between July 2016 and November 2018. Data were collected regarding surgical details, patient demographic information, and patient medical comorbidities. The primary outcome was incidental durotomy, which was identified both through manual extraction and the NLP algorithm. Multivariable logistic regression was used to identify independent predictors of incidental durotomy. Bootstrapping was then employed to estimate optimism in the model, which was corrected for; this model was converted to a calculator and deployed online.
Of the 1279 elective lumbar surgery patients included in this study, incidental durotomy occurred in 108 (8.4%). Risk factors for incidental durotomy on multivariable logistic regression were increased surgical duration, older age, revision versus index surgery, and case starts after 4 pm. This model had an area under curve (AUC) of 0.73 in predicting incidental durotomies. The previously established NLP method was used to identify cases of incidental durotomy, of which it demonstrated excellent discrimination (AUC 0.97).
Using multivariable analysis, the authors found that increased surgical duration, older patient age, cases started after 4 pm, and a history of prior spine surgery are all independent positive predictors of incidental durotomy in patients undergoing elective lumbar surgery. Additionally, the authors put forth the first version of a clinical calculator for durotomy risk that could be used prospectively by spine surgeons when counseling patients about their surgical risk. Lastly, the authors presented an external validation of an NLP algorithm used to identify incidental durotomies through the review of free-text operative notes. The authors believe that these tools can aid clinicians and researchers in their efforts to prevent this costly complication in spine surgery.
Jeff Ehresman, Zach Pennington, Andrew Schilling, Ravi Medikonda, Sakibul Huq, Kevin R. Merkel, A. Karim Ahmed, Ethan Cottrill, Daniel Lubelski, Erick M. Westbroek, Salia Farrokh, Steven M. Frank and Daniel M. Sciubba
Blood transfusions are given to approximately one-fifth of patients undergoing elective lumbar spine surgery, and previous studies have shown that transfusions are accompanied by increased complications and additional costs. One method for decreasing transfusions is administration of tranexamic acid (TXA). The authors sought to evaluate whether the cost of TXA is offset by the decrease in blood utilization in lumbar spine surgery patients.
The authors retrospectively reviewed patients who underwent elective lumbar or thoracolumbar surgery for degenerative conditions at a tertiary care center between 2016 and 2018. Patients who received intraoperative TXA (TXA patients) were matched with patients who did not receive TXA (non-TXA patients) by age, sex, BMI, ASA (American Society of Anesthesiologists) physical status class, and surgical invasiveness score. Primary endpoints were intraoperative blood loss, number of packed red blood cell (PRBC) units transfused, and total hemostasis costs, defined as the sum of TXA costs and blood transfusion costs throughout the hospital stay. A subanalysis was then performed by substratifying both cohorts into short-length (1–4 levels) and long-length (5–8 levels) spinal constructs.
Of the 1353 patients who met inclusion criteria, 68 TXA patients were matched to 68 non-TXA patients. Patients in the TXA group had significantly decreased mean intraoperative blood loss (1039 vs 1437 mL, p = 0.01). There were no differences between the patient groups in the total costs of blood transfusion and TXA (p = 0.5). When the 2 patient groups were substratified by length of construct, the long-length construct group showed a significant net cost savings of $328.69 per patient in the TXA group (p = 0.027). This result was attributable to the finding that patients undergoing long-length construct surgeries who were given TXA received a lower amount of PRBC units throughout their hospital stay (2.4 vs 4.0, p = 0.007).
TXA use was associated with decreased intraoperative blood loss and significant reductions in total hemostasis costs for patients undergoing surgery on more than 4 levels. Furthermore, the use of TXA in patients who received short constructs led to no additional net costs. With the increasing emphasis put on value-based care interventions, use of TXA may represent one mechanism for decreasing total care costs, particularly in the cases of larger spine constructs.