Radiation Exposure to Patients With Acute Deep Venous Thrombosis Treated With Thrombolysis

Abstract

Catheter thrombolysis of acute deep venous thrombosis (DVT) of the upper extremity (UE) and lower extremity (LE) is being increasingly carried out following emerging evidence to support that it reduces the risk for development of post-thrombotic syndrome. Such intervention and its potential secondary procedures may expose the patients to significant cumulative radiation over time. Furthermore, these patients are often relatively younger than those with arterial diseases. The study aimed to assess the cumulative radiation exposure to patients who had thrombolysis for acute DVT of the LE and UE. Patients who had catheter-directed thrombolysis or pharmacomechanical catheter thrombolysis for acute DVT involving the LE and UE in a single unit between May 1, 2012, and April 30, 2016, were identified retrospectively. Demographic data, anatomic DVT, imaging, technical details of the index thrombolysis, follow-up, and estimated radiation exposure measured in dose-area product (DAP) and fluoroscopy time (FT) from related interventions were collected and analyzed. DAP refers to the radiation absorbed by irradiated tissue multiplied by the area irradiated, which gives a rough estimation of the risk of stochastic effects. Mann-Whitney test was performed to assess for statistical differences between subgroups, and P < .05 was considered significant. There were 91 patients (39 men) with LE DVT and 20 patients (12 men) with UE DVT identified. The mean (range) ages of patients undergoing thrombolysis in the LE DVT and UE DVT groups were 43.5 (15-78) years and 39.1 (20-67) years, respectively. The median (range) cumulative DAP for the index thrombolysis was 9238 (204-175,983) mGy∙cm2 for LE DVT and 1982 (115-11,736) mGy∙cm2 for UE DVT (P < .0001). The median cumulative FT for the index thrombolysis was 981 (20-4890) seconds and 837 (19-2895) seconds for LE DVT and UE DVT, respectively (P = .18). The mean follow-up for LE and UE DVT was 16.4 (1-50) months and 4.3 (1-19) months, respectively. During the follow-up, 36 (40%) patients with LE DVT had secondary procedures involving the use of fluoroscopy including venography, thrombolysis, venoplasty, and stent extension. The median (range) cumulative DAP and FT for the secondary procedures in the LE DVT group were 6564 (800-186,495; n = 35) mGy∙cm2 and 876 (96-12,910; n = 32) seconds, respectively. Patients with acute DVT who had thrombolysis appeared to be exposed to radiation that was comparable to that with simple LE arterial angioplasty but much less than with endovascular aortic aneurysm repair reported in the literature. However, these patients were usually much younger than those with arterial diseases and may need secondary interventions involving further radiation exposure in their lifetime. Therefore, further studies should investigate the long-term side effects of radiation exposure in these patients and ways of reducing it, including the use of intravascular ultrasound and magnetic resonance imaging technology.