Intraoperative Type IIIb Endoleak after Endograft Deployment during EVAR

Type IIIb endoleak usually occurs years after the initial endograft implantation, and the cause is the chronic fatigue of the endograft. This rare case describes a type IIIb endoleak, appearing immediately after deployment of a new generation low-profile stentgraft and highlights the diagnostic and treatment challenges associated with the type IIIb endoleak. A 74-year-old man underwent elective EVAR for an infrarenal abdominal aortic aneurysm. A type IIIb endoleak near to the flow divider due to a fabric defect was diagnosed. The endoleak was successfully treated by endovascular positioning of a converter stent graft followed by the occlusion of the left limb with an iliac occluder and a femoro-femoral crossover bypass surgery. The ultrasound scan after 4 weeks showed no sign of endoleak. Occurrence of a type IIIb endoleak immediately after deployment is extremely rare. Based on the convenience of the intraoperative procedure and the anatomic characteristics of the aneurysm, we assume that the fabric defect might have occurred during loading of the endograft and subsequent confinement in the delivery catheter. We cannot definitely rule out the possibility of fabric damage induced by low-pressure balloon instrumentation. In case of a suspicion of a type IIIb endoleak, bilateral balloon occlusion of both limbs followed by antergrade aortography will help to identify the leak. In case the defect is near to the flow divider, aortouniliac grafting followed by femoro-femoral crossover bypass surgery represents an alternative option to conversion to open surgical repair.