901-119 Non-occlusive Prosthetic Thrombosis on Transoesophageal Echocardiography After Mitral Surgery: Evolution with Medical Treatment

Abstract

Transoesophageal echocardiography (TEE) after mitral valve replacement (MVR) with a mechanical prosthesis may reveal non-occlusive thrombi in the prosthesis in asymptomatic patients (pts). The clinical implications of these thrombi remain however debated. Between 1988 and 1993, 183 consecutive pts underwent MVR with a bileaflet prosthesis (Saint-Jude 134, Sorin 22, Carbomedics 20, Duromedics 7). Their mean age was 56 ± 13 yrs. Early TEE was performed 15 ± 6 days after surgery and revealed thrombi in the prosthesis in 22 pts (12%). No pt had symptoms. Two pts were re-operated on because of large, mobile thrombi. In the 20 other cases, Doppler did not show any obstruction in the prosthesis (mean gradient 5 ± 2 mmHg [3–9]), and the motion of both leaflets was normal on TEE and fluoroscopy. A total of 27 thrombi was visualized in these 20 pts. Maximal size of the thrombi was <5 mm in 9 cases, 5 to 10 mm in 12 cases, and >10 mm in 6 cases; 70% of these thrombi were mobile. These 20 pts were treated by carefully controlled anticoagulation with heparin (serum levels 0.2 to 0.4 U/mL) andlor vitamin K antagonists (INR 3 to 4.5). No pt received thrombolytic therapy. Repeat TEE in these 20 pts showed that thrombi disappeared after one month in 15 cases (75%), and in all the cases after a mean period of 58 ± 99 days [7–210]. Only one pt experienced a transient ischaemic attack without sequelae. (1) Non-occlusive thrombi in the prosthesis are frequently observed on early TEE after MVR. (2) They seldom cause embolic events. (3) They disappear with anticoagulant therapy, in the majority of cases within one month.