Proximal anastomotic disruption of an axillofemoral bypass

An 80-year-old male patient arrives to the emergency room with an acute rapid-growing mass lesion in the right pectoral area. He recently underwent a right axillofemoral bypass surgery due to a very symptomatic occlusion of the right iliac artery and a recent coronary stent.

Non-enhanced CT and contrast-enhanced CT in arterial phase and a rescue phase are performed. In the non-enhanced CT a heterogeneous lesion with a hypodense centre is seen surrounding the bypass in the anterior region of the right chest wall. On the arterial phase, contrast extravasation and filling of the lesion is noted, observing a distance of 25mm between the subclavian artery and the bypass. The rescue phase confirms further filling of the lesion. These findings are compatible with a pseudoaneurysm due to disruption of the proximal end of the bypass from the subclavian artery.

Occlusive peripheral arterial disease of the lower limbs is one the most frequent diseases with an impact on the life quality of patients [1]. When symptomatic, claudication is the predominant symptom but can progress to critical limb ischaemia. If clinically suspected, diagnosis should start with an ankle brachial index and be confirmed through imaging techniques such as Doppler and angiography computerised tomography. The latter gives a more anatomical point of view, with a high compliance with the angiography [2], being key on the planification of treatment. Treatment is necessary when there is symptomatic lower extremity ischaemia. There are several treatment options varying from endovascular procedures to surgical grafts. Axillofemoral bypass is a revascularisation procedure used in patients with aortoiliac occlusive disease when an endovascular approach or an aortofemoral reconstruction graft is not possible. It is also an option in poor surgical risk patients or patients with an infected aortic graft or an aortoenteric fistulae [3,4]. The patient must have accessible and healthy axillary or subclavian arteries. Amongst the complications are proximal anastomotic disruption, acute thrombosis of the axillary artery, brachial plexus injury, upper extremity steal phenomenon, thromboembolism and traumatic fracture of the graft. Proximal disruption of the anastomosis between the axillary artery and the graft is a severe early complication secondary to mechanical distress, anastomosis technical errors and infection [5, 6]. Appearance of a rapid growing chest wall mass should raise the suspicion for disruption of the anastomosis or graft fracture. Angio-CT is helpful to depict the defect and exclude other differential diagnosis. The key finding is the localisation of the contrast extravasation, which is at the proximal anastomotic end of the bypass graft. This is seen on the arterial phase of the angio- CT. A non-enhanced CT is helpful for a better localisation of the proximal end of the graft and the surgical clips and a rescue phase for a better depiction of the pseudoaneurysm. Post-surgical treatment seroma or a haematoma would not fill with contrast. Haematoma’s high-attenuation values on non-enhanced CT help to differentiate it from a pseudoaneurysm. Treatment options are placement of an interposition graft or a stent to cover the axillary defect and stop the bleeding. In our case, due to extensive bleeding the treatment option was stenting of the subclavian artery to avoid leakage and ligation of the proximal end of the bypass. Written informed patient consent for publication has been obtained.