Incidence of Deep Venous Thrombosis Post Cardiac Surgery: A Prospective Observational Duplex Venous Screening

BackgroundPrior studies investigating deep vein thrombosis (DVT) post cardiac surgery have included mostly on pump cardiac surgery. We aimed to evaluate the frequency of DVT in consecutive series of patients undergoing cardiac surgery by sequential Duplex Venous Sonography (DVS). MethodsA single center prospective cohort study conducted on patients undergoing cardiac surgery from 2012 to 2014. All patients underwent sequential DVS at three-time intervals: Preoperatively, Day of Discharge and 5 weeks Postoperatively. A subgroup analysis was done to compare DVT and non-DVT groups to look for possible predictors for development of DVT. Results124 patients underwent screening DVS. 77.4% underwent off-pump CABG, 2.4% on-pump CABG, and 20.1% valve surgery. Positive asymptomatic DVS was observed in 11 of 124 eligible patients (8.9%). Off-pump CABG (10 of 96; 10%) and valve replacement/repair (1 of 25; 4%). Mean age of the DVT and non-DVT groups was 65.5{+/-}9.3 and 66.0{+/-}10.2 and females were 18% and 29%, respectively. The groups did not differ in surgical time (3.9{+/-}1.0 vs. 3.8{+/-}1.0 hours), intubation time (14.9{+/-}7.0 and 12.1{+/-}5.3 hours) and length of stay (6.7{+/-}5.0 and 6.6{+/-}5.4 days), DVT and non-DVT groups, respectively. Patients with DVT had a higher requirement for blood transfusions (55% vs. 20% [P<0.05]). Thirty-day hospital readmissions were 9% for DVT versus 13% for non-DVT. All patients received thromboprophylaxis and physical therapy postoperatively. ConclusionsTo our knowledge, first of its kind, a prospective, observational DVS study to evaluate DVT in Cardiac Surgery patients. Despite optimal thromboprophylaxis, 9% of cardiac surgery patients develop otherwise asymptomatic DVT when off-pump CABG is performed. Off pump CABG may have better outcomes with respect to postoperative DVT. We found thromboprophylaxis combined with physical therapy to be safe and effective to prevent symptomatic DVT, whereas routine preoperative screening did not influence the results in our study. Despite limited sample size, we found the DVT group included a higher percentage of patients who smoked, required blood transfusion and experienced prolonged intubation or reintubation.