P885 Pulmonary artery stent implantation in an adult with chronic thromboembolic pulmonary stenosis

Abstract Introduction Pulmonary artery stenosis presenting in adults is rare. Chronic thromboembolic pulmonary hypertension (CTEPH) is by far the most common cause of pulmonary artery stenosis. Stenosis in these patients are not caused by an abnormality of the arterial wall itself, but by intraluminal narrowing as a result of the only partially resolved and organized thromboembolism. In contrast to paediatric patients, in adults with pulmonary artery stenosis, pulmonary stenting is not routinely performed. Case report A 51-year male, smoker, diabetic, hypertensive, and with chronic kidney disease. He was diagnosed two years earlier with bilateral multiple pulmonary emboli and was maintained on oral anticoagulation therapy. Recently, he presented with gradually progressive shortness of breath and signs of right ventricular failure. Diagnostic imaging: 1-Transthoracic and transesophageal echocardiography showed normal global systolic left ventricular function with no regional wall motion abnormalities, dilated right ventricle (RV) with moderately impaired function, severe pulmonic valve incompetence, mild tricuspid incompetence and a severely elevated right ventricular systolic pressure (RVSP) of 82 mmHg. In addition, a small rounded mass (6 x 11 mm) was visualized attached to the posterior wall of the RV outflow tract (RVOT) about 15mm proximal to the pulmonary valve annulus, (figure A). 2- Computed tomography pulmonary angiography showed a right main pulmonary artery (RPA) with circumferential narrowing, which was highly suggestive of chronic thrombosis. There was an abrupt tapering noted in the segmental branches of the right lower lobar pulmonary artery, with non-opacification of the distal arteries. No contrast opacification was noted in the right upper lobe pulmonary arteries. The left main pulmonary artery showed thickening of its bifurcation, again suggestive of chronic thrombosis, with narrowing of its left upper lobar branch, (figures B&C). 3-Cardiac magnetic resonance (CMR) showed a non enhancing RVOT mass protruding through the incompetent pulmonary valve during systole with features suggestive of a thrombus. Management In view of the clinical history, CTEPH was considered to be the most likely aetiology of the pulmonary hypertension. The decision was to perform balloon angioplasty and stent implantation in the RPA. Immediately after the procedure, RVSP was reduced from 80 to 50 mmHg. The clinical course after this procedure was uncomplicated and the patient showed significant clinical improvement. Follow up CMR showed patent stent with improvement of RV function ( fig D) Abstract P885 Figure.