J. H. Helm1, M. C. Helm1, J. C. Gould1 1Medical College Of Wisconsin,General Surgery,Milwaukee, WI, USA
Introduction: Blood transfusions are known to affect the clotting cascade and inflammatory pathways of the circulatory system. This may further increase the risk of venous thromboembolism (VTE), particularly in the setting of a separate prothrombotic stimulus- major abdominal surgery. VTE defined as deep vein thrombosis (DVT) or pulmonary embolism (PE) is a serious complication affecting morbidity and mortality outcomes in general surgery patients. The aim of this study was to evaluate the association between bleeding requiring a perioperative blood transfusion and the incidence of postoperative VTE in ventral hernia patients.
Methods: The American College of Surgeons National Surgery Quality Improvement Program (NSQIP) was queried for non-emergent open (n=37,591) and laparoscopic (n=11,895) ventral/incisional hernia repairs (VHR) that occurred between 2013 and 2015. Univariate and multivariate regression analyses were used to determine factors predictive of VTE development within 30-days of surgery. Additional analyses were conducted to determine the subsequent impact of bleeding requiring transfusion on the development of VTE, based on surgical approach.
Results: The overall rate of bleeding requiring transfusion was 1.5% (1.3% open, 1.9% lap; p<0.0001). DVT was diagnosed an average of 12.7 days and PE 10.2 days after surgery. There was no difference in the rate of VTE between groups (both 0.4%). Of the patients that had data available, 48.5% (n=176) experienced the VTE after discharge. There was no difference in the length of stay between groups, however patients who underwent open repair were younger (56.3 vs. 57.4 years; p<0.0001) and experienced shorter operating room times (100.6 vs. 114.5 minutes; p<0.0001). Increased age, operative time, length of stay, and comorbidities including ASA class III/IV, metabolic syndrome, chronic obstructive pulmonary disease (COPD), dialysis, CHF, disseminated cancer, chronic steroid use, bleeding disorder, and transfusion prior to surgery increased perioperative bleeding risk (p<0.05). A single blood transfusion following open VHR increased the risk of venous thromboembolism 8.9-fold (p<0.0001). Predictive risk factors for VTE following transfusion included age, perioperative complication, ASA class III/IV, bleeding disorder, and COPD.
Conclusion: To our knowledge this is the first study exploring the risk of venous thromboembolism development following perioperative blood transfusions in ventral hernia patients. Bleeding and blood transfusion may lead to an increased rate of VTE following surgery due to a hypercoagulable state induced by the transfusion, by withholding chemoprophylaxis in patients who bleed, by a combination of these factors, or other factors. As nearly half of these thrombotic events are diagnosed after discharge from the hospital, close clinical follow up and selective outpatient VTE chemoprophylaxis is highly recommended.