[Aortocolic fistula as a rare complication of aorto-iliac aneurysms]

Primary aortocolic fistula is a rare complication of infrarenal abdominal aortic aneurysm. Many case reports have been published along with small series but the incidence of primary aortocolic fistulae remains unknown. In contrast, the incidence of secondary aortocolic fistulae increases approximately up to 1.5-4.0% as a result of rapid evolution of aorto-iliac vascular reconstruction with prosthetic grafts. The prognosis of aortocolic fistulae mainly depends on the time interval between first clinical manifestations and operative treatment. Loss of time by detailed preoperative investigations worsens the critical situation of the patient. The high mortality is mainly due to the sequelae of hemorrhagic shock, and in a lesser degree to graft infection. Therefore the principal operative treatment is to stop bleeding in order to reduce the sequelae of hemorrhagic shock. The method of choice for vascular reconstruction is the extra-anatomic axillobifemoral bypass as a time-saving and uncomplicated operation to avoid fatal graft infection and to ensure sufficient arterial blood supply to the lower limbs. Any enteral bleeding of patients with aorto-iliac aneurysm or with a history of aorto-iliac prosthetic substitution has to be considered as an aortointestinal or an aortocolic fistula until the opposite is proven. This consideration is decisive for the prognosis of aortocolic fistulae. The operation treatment of all diagnosed aorto-iliac aneurysms, as well as the ultrasound control of all aorto-iliac prosthetic reconstructions, are possible preventive measures.