We report the case of an acute ischemia of the superior mesenteric artery (SMA) after endovascular fenestration of a complicated acute type B aortic dissection. An initial attempt for endovascular revascularization of the SMA failed, and an ascending aorto-superior mesenteric artery bypass was urgently performed to salvage the small bowel. Surgery of patients in these specific settings is more complex because an adequate, more distal inflow vessel is often not present due to the dissected aorta and iliac arteries. This surgical option could be lifesaving and should be part of the vascular surgeon's armamentarium.