Mechanical thrombectomy in experimental acute pulmonary embolism

Abstract

Objective To evaluate the efficacy and safety of different interventional therapy techniques in the treatment of acute pulmonary embolism. Methods Twenty-eight dogs were divided randomly into 4 groups: helix thrombectomy device (HTD) group, urokinase (UK) group, HTD with UK (HTD+UK) group, and control group. HTD was performed within 10 minutes through catheter in HTD group. 100 000 U of UK was given to all of the UK group doges over 30 min. HTD with UK was conducted in HTD+UK group. The control group received only a 30 min infusion of saline solution. PAMP, SBP, gasometric parameters, and pulmonary angiography was observed before and immediately, 30 min, 1 hour, 2 hours after the therapy. The specimens of lung were made for gross evaluation and histology of HE. Result In every group, pulmonary artery mean pressure (PAMP) at 30 min after the therapy was as follows: control group (33.5±3.38) mm Hg, UK group (29.00±3.96) mm Hg, HTD group (29.39±3.17) mm Hg, HTD+UK (25.24±3.04) mm Hg(q=6.88, P=0.002);at 60 min, control group (33.19±3.54)mm Hg, UK group (28.79±3.96)mm Hg, HTD group (24.44±3.70)mm Hg, HTD+UK group (23.57±4.57)mm Hg(q=8.73, P=0.000);at 120 min, control group (31.50±3.75)mm Hg, UK group (26.43±4.04)mm Hg, HTD group (22.00±3.62)mm Hg, HTD+UK group(17.86±3.26)mm Hg(q=17.78, P=0.000). A significant decrease in PAMP after the treatment at the time of 30 min, 1 hour, and 2 hour was observed compared with those in control group. The difference in PAMP between HTD group and UK group at 120 min after therapy was significant (P0.05). The overall PAMP of HTD+UK group at 30 min and 120 min had a significant decrease compared with UK group and HTD group (P0.05), and had significant difference at 60 min compared with UK group. SBP of every group showed no difference. The pulmonary artery angiography after treatment in every therapy group showed that the occlusive artery was restored and the pulmonary artery circulation was improved. The autologous embolus could be seen in pulmonary arteries in pathology. Focal intimal injury in the pulmonary artery was made by HTD. Conclusion HTD combined with thrombolytic treatment is safe, and it has better results than HTD or pharmacologic fibrinolysis alone.