Successful endovascular management with a covered stent of an external iliac pseudoaneurysm following allograft nephrectomy using CO2 as contrast medium: a case report oleh Federico Fontana, MD, Filippo Piacentino, MD, Christian Ossola, MD, Marco Curti, MD, Andrea Coppola, MD, Giulio Carcano, MD, Gabriele Piffaretti, Phd, Matteo Tozzi, MD, Massimo Venturini, MD