M. P. DeWane1, A. A. Maung1, K. A. Davis1, J. P. Geibel1, R. D. Becher1 1Yale University School Of Medicine,Department Of Surgery,New Haven, CT, USA
Introduction: Repair of incisional hernias is one of the most common operations performed by general surgeons. However, outside of its classification as a “major” general surgery operation, little is known about the risk of venous thromboembolism (VTE) after this common procedure. This is concerning as VTE is a leading cause of death in surgical patients. We evaluated VTE rates after emergent and elective incisional hernia repairs to define risk factors, mortality, and determine time to VTE events. We hypothesized that emergent operations would put patients at an increased risk for VTE events.
Methods: Open and laparoscopic incisional hernia repairs were identified in the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) participant user files (PUF) over a five year period, from 2010 to 2014. Patient demographics, perioperative variables, and well-established VTE risks were assessed. Logistic regression models determined the risks of VTE development, including the importance of emergent operative classification. Kaplan-Meier and Cox regression analyses determined timing to 30-day VTE events.
Results: A total of 30,372 patients were included in the analyses, 15.7% of whom underwent emergent hernia repair. Compared to elective procedures, incisional hernia operations performed emergently had significantly increased odds for developing VTE (2.16% vs 0.86%; Odds Ratio [OR] 2.51; p<0.0001). Emergent operative classification was found to be an independent predictor of VTE (OR 1.67; p=0.0007) after accounting for common VTE risks. Other VTE risk factors included: respiratory issues such as unexpected or prolonged post-operative intubation (OR 4.12, p<0.0001), need for reoperation (2.52, p<0.0001), and laparoscopic case (OR 1.54, p=0.0287). Variables which did not significantly predict risk of VTE included age, primary vs recurrent hernia, length of operation, need for bowel resection, and obesity. In patients who developed VTE, the risk of mortality was significantly increased (OR 2.57, p=0.0311). Patients presenting in extremis with pre-operative sepsis from incarcerated hernias who required prolonged postoperative ICU stays had a VTE risk 13 times greater than baseline (11.94% vs 0.86%; p<0.0001).
Conclusion: VTE events are significantly more likely to occur in patients undergoing emergent compared to elective incisional hernia repair. Even after controlling for the multiple reasons for this patient-population to develop VTE, emergent operative classification independently predicts VTE, and should be considered a high-risk characteristic. Emergent patients diagnosed with VTE had poorer survival. These findings highlight the importance of VTE prevention and prophylaxis in this high-risk patient population, and suggest that emergent operations may play a role as a thrombogenic stimulus.