Wallstent Migration into the Right Ventricle Causing Severe Tricuspid Regurgitation and Right Ventricular Perforation

Abstract

Endovascular stents are being used with increasing frequency for various problems of the venous system, but they have been associated with numerous complications. We report the case of an 88-year-old woman who presented with persistent, progressive dyspnea. Imaging revealed a migrated stent lodged in the tricuspid valve and extending into the right ventricle, causing severe tricuspid regurgitation. After a failed attempt at endovascular retrieval, emergent surgical removal was successful. During surgery, the stent was found to be embedded in the tricuspid leaflets, and part of the stent had also perforated the right ventricle.

Review of the patient's records revealed that 2 WALLSTENT® venous endoprostheses had been placed 6 months earlier to treat stenosis of the left brachiocephalic vein and, further, that the migrated stent had been visible on outpatient chest radiography performed 4 months after the stent placement. This case emphasizes the need to consider the possibility of stent migration in patients who present with unusual symptoms.

We report the case of a patient who presented with dyspnea on minimal exertion. This patient had undergone endovascular stent placement 6 months earlier to treat stenosis of the left brachiocephalic vein. We describe the diagnosis and treatment of an unusual complication.

Case Report

An 88-year-old woman was referred to the pulmonary clinic at our institution for evaluation of persistent, progressive dyspnea on minimal exertion. Her medical history included hypertension, diabetes mellitus, and hemodialysis for end-stage renal disease. Results of a prior cardiac evaluation, which included coronary angiography and echocardiography, were reported as normal.

A computed tomographic scan of the chest revealed an occluded stent within the left brachiocephalic vein and a migrated stent that was lodged in the tricuspid valve and extended into the right ventricle (Fig. 1). Echocardiography confirmed the presence of a metallic stent across the tricuspid valve that was causing severe tricuspid regurgitation (Figs. 2 and 3).

Fig. 1 Computed tomogram of the chest shows 2 endovascular stents: one in the left brachiocephalic vein (arrowhead) and the other one dislodged, protruding through the tricuspid valve and right ventricle (arrow).

Fig. 2 Transthoracic echocardiogram shows a metallic stent (arrow) across the tricuspid valve. LV = left ventricle; RA = right atrium; RV = right ventricle

Fig. 3 Transthoracic color-flow Doppler echocardiogram shows severe tricuspid regurgitation through the lumen of the stent.

After a failed attempt at endovascular retrieval, a WALLSTENT® venous endoprosthesis (Boston Scientific Corporation; Natick, Mass) was removed surgically through a median sternotomy with use of cardiopulmonary bypass. The stent, which was 4 × 1.5 × 1.5 cm in size, was embedded and had epithelialized in the tricuspid valve leaflets. It projected distally into the right ventricle, where it had perforated the posterior wall (Fig. 4). After the stent was removed, the leaflets of the tricuspid valve appeared to be intact. Test injection of the valve with saline solution confirmed that the tricuspid valve was competent with minimal residual regurgitation. The posterior wall of the right ventricle was repaired using 2 interrupted, pledgeted, horizontal mattress sutures. The other stent was left alone for the time being. The patient was hemodynamically stable after the operation, and she was extubated the next morning.

Fig. 4 Intraoperative photograph of the opened right atrium shows the WALLSTENT® embedded across the tricuspid valve. The distal end of the stent was projecting into the right ventricle and had perforated the posterior wall.

Upon further investigation, we learned that the patient had undergone fistulography of her left arm arteriovenous graft 6 months earlier, with angioplasty and placement of 2 WALLSTENT endoprostheses (12 × 40 mm and 12 × 60 mm) in the left brachiocephalic vein to treat a highly resilient stenosis. We also discovered that one of the stents had then apparently migrated proximally and was visible on an outpatient chest radiograph obtained 2 months before her current presentation.

Discussion

Endovascular stents can be used to salvage vascular access in hemodialysis patients, to treat lesions after failed angioplasty, and to treat central venous catheter stenoses. Complications associated with endovascular stents include stent thrombosis, pseudoaneurysm, infection, stent migration, and restenosis due to intimal hyperplasia. The reported rate of stent migration is less than 3%.^1,2

A case can be made for leaving a migrated stent in place if it is not producing clinical consequences. However, removal of the stent may avert infection, perforation, heart failure, and embolization into the pulmonary artery and pulmonary tree. In our patient, stent removal was necessary, because the migrated stent was causing tricuspid regurgitation and had perforated the right ventricular wall.

We anticipate that, as endovascular stenting becomes more common, reports of various complications such as stent migration will become more frequent. In the meantime, when a patient presents with an unusual problem such as our patient did (rapid-onset congestive heart failure with no apparent precipitating factors), or with other problems such as pericardial tamponade, arrhythmias, or pulmonary embolism, the possibility of stent migration should be considered. If endovascular retrieval of a dislodged stent is unsuccessful, surgery will be required.