Risk, Clinical Features, and Outcomes of Thrombosis Associated With Pediatric Cardiac Surgery

Abstract

Background— Thrombosis, usually considered a serious but rare complication of pediatric cardiac surgery, has not been a major clinical and/or research focus in the past. Methods and Results— We noted 444 thrombi (66% occlusive, 60% symptomatic) in 171 of 1542 surgeries (11%). Factors associated with increased odds of thrombosis were age <31 days (odds ratio [OR], 2.0; P =0.002), baseline oxygen saturation <85% (OR, 2.0; P =0.001), previous thrombosis (OR, 2.6; P =0.001), heart transplantation (OR, 4.1; P <0.001), use of deep hypothermic circulatory arrest (OR, 1.9 P =0.01), longer cumulative time with central lines (OR, 1.2 per 5-day equivalent; P <0.001), and postoperative use of extracorporeal support (OR, 5.2; P <0.001). Serious complications of thrombosis occurred with 64 of 444 thrombi (14%) in 47 of 171 patients (28%), and were associated with thrombus location (intrathoracic, 45%; extrathoracic arterial, 19%; extrathoracic venous, 8%; P <0.001), symptomatic thrombi (OR, 8.0; P =0.02), and partially/fully occluding thrombi (OR, 14.3; P =0.001); indwelling access line in vessel (versus no access line) was associated with lower risk of serious complications (OR, 0.4; P =0.05). Thrombosis was associated with longer intensive care unit (+10.0 days; P <0.001) and hospital stay (+15.2 days; P <0.001); higher odds of cardiac arrest (OR, 4.9; P <0.001), catheter reintervention (OR, 3.3; P =0.002), and reoperation (OR, 2.5; P =0.003); and increased mortality (OR, 5.1; P <0.001). Long-term outcome assessment was possible for 316 thrombi in 129 patients. Of those, 197 (62%) had resolved at the last follow-up. Factors associated with increased odds of thrombus resolution were location (intrathoracic, 75%; extrathoracic arterial, 89%; extrathoracic venous, 60%; P <0.001), nonocclusive thrombi (OR, 2.2; P =0.01), older age at surgery (OR, 1.2 per year; P =0.04), higher white blood cell count (OR, 1.1/10 9 cells per 1 mL; P =0.002), and lower fibrinogen (OR, 1.4/g/L; P =0.02) after surgery. Conclusions— Thrombosis affects a high proportion of children undergoing cardiac surgery and is associated with suboptimal outcomes. Increased awareness and effective prevention and detection strategies are needed.