Acute Type B Dissection Causing Collapse of EVAR Endograft and Iliac Limb Occlusion.

We describe a rare case of acute type B dissection (ATBDs) causing collapse of a previously placed infrarenal stent graft, resulting in acute limb ischemia due to left iliac limb thrombosis in a 59-year-old male. The patient presented with acute back and abdominal discomfort radiating to his back, bilateral buttock stabbing discomfort and left > right thigh and calf rest pain. CT angiography showed a spiral type B dissection with collapse of the proximal portion of the endovascular repair of aortic aneurysm (EVAR) device and left limb occlusion. Urgent treatment with thoracic endovascular aortic repair distal to the left subclavian covered the entry tear and redirected the majority of the flow to the true lumen leading to near immediate expansion of the proximal portion of the EVAR device. After surgical femoral control, balloon embolectomy of the occluded iliac limb was performed and the limb relined. His lower extremity ischemic symptoms resolved, and his abdominal and back pain dissipated. At latest 6-month follow-up, CT angiography shows an intact thoracic endovascular aortic repair stent graft and a widely patent EVAR stent graft, and the patient has no further abdominal, back, or leg symptoms. ATBD causing proximal abdominal EVAR collapse is an extremely rare presentation of false lumen pressurization and can be treated similarly to complicated type B dissection with the goal of restoring true lumen patency.