Risk of symptomatic venous thromboembolism after abdominal aortic aneurysm repair in long-term follow-up of 1021 consecutive patients.

OBJECTIVE: Venous thromboembolisms, including deep vein thromboses and pulmonary embolisms, are infrequent but consequential and potentially preventable complications following major surgical procedures. The aim of the study was to describe the long-term occurrence of symptomatic venous thromboembolism in patients undergoing abdominal aortic aneurysm repair and to ascertain patient-specific risk factors as well as to compare the rate to that of a reference population. METHODS: The study included all patients that had undergone endovascular or open abdominal aortic aneurysm repair, both elective and urgent/acute cases, at the Tampere University Hospital, Finland, between February 2001 and December 2016. Fifty-nine percent of patients had undergone endovascular and 41% open repair, and 23% of all cases had required urgent or emergency treatment. Information regarding later treatment episodes for symptomatic venous thromboembolism as well as survival data were obtained from national registries. The reference population was obtained from national registries with a random sample of inhabitants matched for age, sex, and the location of residence with a 4:1 ratio and was analysed similarly. RESULTS: Altogether 1021 patients and 4065 controls were included (88% male, median age 74 in both groups). The high-risk period for venous thromboembolisms lasted for approximately three months, and during that time, their occurrence was highest in in patients with coronary disease (2.5%), following open repair (2.4%) and in urgent or emergency setting (2.6%), while the rate was low after endovascular aortic repair (1.0%). The cumulative incidence of venous thromboembolism at three months, one year, three years, and five years was 1.1%, 1.6%, 2.7%, and 4.5% in patients and 0.1%, 0.3%, 1.0%, and 1.8% in the reference population, respectively, p<0.001 each. Most venous thromboembolisms were pulmonary embolisms in the patient group. The five-year mortality rates were 37.9% in patients and 23.8% in controls, p<0.001. CONCLUSIONS: The incidence of symptomatic venous thromboembolisms, particularly pulmonary embolisms, after abdominal aortic aneurysm repair is significant, both in short- and long-term follow-up. Open surgery, acute setting, and concomitant coronary disease appear to increase the risk.