Images in vascular medicine. Distal abdominal aortic occlusion.

A 41-year-old woman presented complaining of discomfort in the gluteal region while walking. She initially developed claudicationwhile walking up hills, which progressed over 4 months to discomfort after walking only 200 feet (61m). Past medical history included diet-controlled hypertension and remote history of cigarette smoking. On physical examination, blood pressure was 120=80 in the left arm and 130=80 in the right arm. The femoral, posterior tibial and dorsalis pedis pulses were not appreciated bilaterally. There were no bruits present and no evidence of livedo reticularis on the skin. Laboratory studies included total cholesterol of 208, triglycerides 83, low density lipoprotein 130 and high density lipoprotein of 59mg=dl. Testing for thrombophilia was negative. A lower extremity vascular laboratory study revealed a right ankle–brachial index (ABI) of 0.55 and a left ABI of 0.51 with segmental pressures and pulse volume recordings consistent with bilateral aorto-iliac occlusive disease. The complete blood count and chemistry tests were within normal limits. An echocardiogram and carotid ultrasound were normal and an electron beam computed tomography scan had a calcium score of 9. An abdominal X-ray angiogram (Panel A) revealed total occlusion of the distal abdominal aorta occurring at a level just distal to the origin of the inferior mesenteric artery. There is reconstitution of the iliac vessels via collaterals derived from the inferior mesenteric artery. The common iliac arteries were uniformly small in caliber but without any localized areas of stenosis. The femoral, popliteal and trifurcation vessels were patent. The posterior tibial arteries were patent and in continuity down to the level of the ankles bilaterally. The patient was offered vascular surgery which she declined, opting for a rigorous exercise program. She maintained an exercise program, a low-cholesterol diet and medications which included a statin and an anti-platelet agent (clopidogrel). Four years after initial presentation the ABI increased to 0.7 bilaterally. The patient can currently walk approximately 1 mile (1.6km) on  at ground without any lower extremity discomfort and notes bilateral calf discomfort only when walking up hills. The patient describedhas distal abdominal aortic occlusionwith narrowing of the common iliac arteries. The narrow iliac arteries suggest that the patient may have had an asymptomatic narrowing of the distal abdominal aorta before complete occlusion occurred. There are many different terms in the medical literature used to describe congenital narrow distal aorta. The more commonly used terms are mid-aortic dysplasia, mid-aortic (dysplastic) syndrome, atrophy of the aorta, atresia of the terminal aorta, atypical coarctation, and hypoplasia of the abdominal aorta. The patient’s history and radiographic images suggest a coarctation of the distal abdominal aorta. Coarctation of the aorta is de ned as luminal narrowing of the aorta that produces hemodynamically signi cant obstruction to blood  ow. Coarctation at the attachment of the ductus arteriosus accounts for approximately 98% of the aortic coarctations. Abdominal aorta coarctation is exceedingly rare and found in fewer than 2% of all cases. Additionally, further classifying the coarctation as Panel A