Aorto-enteric fistula is a potentially disastrous condition presented most of the times after a previous AAA repair, open or endovascular. There are various options of treatment: aortic ligation and extra-anatomic bypass, autologous veins reconstruction (NAIS procedure), or in-situ interposition graft. What is the best solution? Here is a way of thinking.
It all depends on the patient’s clinical situation:
- Hemodynamic status
- Septic status
- General health reserve capacity
A hemodynamically stable patient can have a definite solution such as the NAIS procedure, or aortic ligation and extra-anatomic (axillo-femoral) bypass. In this case, the autologous graft (usually femoral veins) preparation or the extra-anatomic bypass must precede the aortic graft explantation. Thus, there will be not ischemia of lower limbs after graft removal, or the time of lower limbs ischemia will be reduced to the time needed to perform the arterial reconstruction using the already retrieved femoral veins.
On the contrary, an unstable patient, or a patient who presents with active upper GI bleeding, does not have the time for a prior revascularization procedure or time for autologous (femoral vein) grafts preparation. In this situation, open laparotomy followed by aortic control is mandatory. What can you do for the arterial tree reconstruction after the graft removal? Something fast. Either an in-situ (orthotopic) synthetic graft or an off-the-self autologous graft, either a custom-made graft by bovine pericardium, or a frozen autologous graft if it is available. It is almost certain, that if you select to ligate or cross-clamp the aorta and then try to construct either an axillo-femoral bypass or retrieve the femoral veins for a NAIS procedure, then the lower limbs ischemia time will be significant and probably, even if your procedure is successful, you will end up with a severe, possibly lethal, ischemia-reperfusion injury.