Viabahn stent graft in the management of pseudoaneurysm arising from a PTFE haemodialysis graft

Clinical History

A patient presented with renal failure, and he had a loop graft in the left elbow, because of which he developed pseudoaneurysms.

Imaging Findings

A 36-year-old man presented with a loop PTFE brachial-basilic graft in the left elbow, which had been done 8 years ago. He subsequently developed pseudoaneurysms on both the inflow and the outflow limb of the graft (Fig. 1), as a result of repeated needle insertions for performing dialyses. Informed consent was obtained from the patient. The venous side of the graft was punctured and a 9F sheath was placed. The loop was negotiated using a 4F Cobra catheter (Cordis Corp, Miami, Florida, USA) over a Terumo wire (Terumo Corp, Tokyo Japan). The Terumo wire was then exchanged for an Amplatz stiff wire (Boston Scientific Corp, Miami, Florida, USA). The pseudoaneurysm on the arterial side of the graft was managed first by using an 8 mm by 5 cm Viabahn stent graft (WL Gore &Associates Inc. Flagstaff, Arizona, US) followed by the pseudoaneurysms on the venous side by using a 7 mm by 5 cm Viabahn stent graft (WL Gore & Associates Inc. Flagstaff, Arizona, US). It was easy to use the stent graft and all pseudoaneurysms were found to be excluded (Fig. 2). There were no immediate complications. Although the graft was then not being used for dialysis, it was considered desirable to preserve it, should dialysis be required in the future. In order to avoid puncturing the stent graft with a dialysis needle, thereby damaging the mesh, the skin at either end of each of the stent grafts was tattooed to mark their positions. A duplex scan taken four weeks after stenting showed that the pseudoaneurysms were completely excluded.

Discussion

Pseudoaneurysm is known to be a recognized complication that manifests on PTFE or venous loop arteriovenous fistula formation with an incidence of 2%–10%. Such pseudoaneurysms are caused by repeated needling of the graft at the same site during haemodialysis. Contributing factors include large needles, poor puncture technique and puncture before the graft has a chance to 'mature'. Many cases may not need any intervention, but others may lead to recurrent fistula thrombosis, infection, skin ulceration and rupture. Such cases would then need surgery. There are several reports of managing such cases using stent grafts. This method provides a less invasive alternative. Other advantages include access to continuous haemodialysis, reduced blood loss and prevention of the need to resite the fistula. The grafts used include Cragg Endo-Pro stent grafts, balloon-expandable Palmaz stents covered with a PTFE graft and Wallgraft. Selby et al. have used detachable balloons to exclude the fistula. Self-expanding stents are preferable, as they conform better to the shape of the loop graft. The Viabahn graft has the advantage of requiring only a 9 French sheath, compared to the 12 French sheath needed for the Wallgraft. Care must be taken to avoid repeated and traumatic punctures as these may lead to graft thrombosis and recurrence of the pseudoaneurysm. To meet this, the skin was tattooed to mark the ends of the stent graft and the patient and our nephrology colleagues were informed accordingly. This was also documented in the patient’s notes and reports. Silas and Bettmann reported on three patients who continued to have needling of stent grafts after exclusion of pseudoaneurysms. Regular monitoring is the key to ensure long term patency of the dialysis fistula. This can be done by undergoing a periodic duplex scan.

Differential Diagnosis List

Final Diagnosis

Management of pseudoaneurysms arising from a dialysis graft.

URL:	https://www.eurorad.org/case/3246
DOI:	10.1594/EURORAD/CASE.3246
ISSN:	1563-4086