Successful treatment of false aneurysm of a saphenous vein bypass graft with fistula to the anterior chest wall using "covered" intracoronary stents.

A 63 year old woman presented to her local hospital with a painful anterior chest wall swelling. Two years previously she had undergone uncomplicated aortic valve replacement (mechanical prosthesis) and coronary artery bypass grafting. She had remained well following her surgery until three months before presentation when she had first noticed chest wall discomfort. The swelling had progressively enlarged until the time of presentation. Examination revealed a 12 × 8 cm pulsatile swelling over the left parasternal region with a palpable thrill. She was otherwise well with normal prosthetic valve sounds. Subsequent transthoracic and transoesophageal echocardiography, computed tomography, magnetic resonance imaging, and aortography demonstrated a large fluid filled cavity anterior to the right ventricle, compressing the right ventricle and outflow tract, and containing an epicardial pacing lead. No communication with the aorta or cardiac chambers could be identified. After preparation for femoral bypass the median sternotomy was reopened and a large presternal haematoma was identified in association with necrotic costal cartilage. The haematoma was evacuated but again no communication could be identified; following evacuation of the haematoma there appeared to be good haemostasis. It was hypothesised that the palpable pulsation had been transmitted from the pulmonary artery Initial progress was satisfactory, but the patient’s subsequent clinical course was complicated by recurrence of the swelling and several episodes of recurrent bloody discharge from a sinus on the chest wall requiring further hospital admission, culminating in a profuse, self limiting haemorrhage causing haemodynamic collapse. At this time coronary angiography demonstrated a false aneurysm of the body of the left anterior descending (LAD) vein graft (fig 1), but no track to the chest wall was identified. Although modestly stenosed, the graft was widely patent with good distal run oV into the LAD artery. The native vessel was occluded and left ventricular contraction (as assessed by echocardiography) remained normal. The remaining vein grafts were patent. An initial attempt at endovascular occlusion of the false aneurysm comprised placement of a Wallstent (Schneider, Staines, Middlesex, UK) across the neck of the aneurysm with a view to subsequent delivery of coils into the aneurysm sac through a Tracker-18 catheter (Target Therapeutics, St Albans, Herts, UK). Although an in vitro model suggested that the Tracker delivery catheter would readily pass through the cells of the Wallstent when deployed, in vivo it proved impossible to enter the aneurysm sac with the catheter despite successful placement of a guidewire. A further attempt using a smaller delivery catheter was planned, but prior imaging demonstrated a considerable increase in the size of the false aneurysm (fig 1), and in the interim the advent of covered stents oVered an alternative solution. A 19 mm Jostent coronary stent graft (JoMed International AB, Helsingborg, Sweden) was deployed across the aneurysm neck and postdilated using a 5.5 mm balloon (Bypass Speedy, Schneider) to a maximum pressure of 18 atm. Although much reducing flow into the false aneurysm a small jet of contrast persisted, therefore, a second similar stent was deployed overlapping the first. Again a small jet of contrast could be seen entering the aneurysm neck, and a third covered stent (12 mm) was deployed. Despite final dilatation to 20 atm with a 6 mm balloon, a jet of contrast still entered the aneurysm (fig 1). We decided to accept this result and manage the patient without anticoagulant or antiplatelet treatment. Over the ensuing weeks the discharging sinus dried and healed, and repeat angiography eight weeks later showed no communication from the LAD vein graft. There was moderate instent restenosis, but in the absence of anginal symptoms no further intervention was planned. Anticoagulation was restarted.