Endovascular treatment is a first-line treatment for renal arteriovenous malformations (AVMs). Endovascular treatment might be effective in patients with aneurysmal-type renal AVMs, which involve one feeding artery and one drainage vein, because control of the feeding artery, rather than the aneurysm itself, could have a therapeutic effect. Herein, we describe two cases of patients with renal AVM with multiple renal artery aneurysms, who were treated by controlling the arterial inflow alone. In Case 1, the patient was a 76-year-old woman with renal AVM discovered during examination for another medical condition. A computed tomography scan revealed four renal aneurysms (φ38/44/24/35 mm) ranging from an intimal defect in the right renal artery to the drainage vein running into the inferior vena cava (IVC). Although we had planned to use a covered stent in the right renal artery to cover the intimal defect without embolization of the aneurysms, a minor artery proximal to the aneurysm was found near the orifice of the right renal artery. Therefore, we used a covered stent in the right renal artery after embolization of the most proximal aneurysm was performed. In Case 2, a 78-year-old man was referred to our facility because a renal AVM was found during examination for lower back pain. The distal posterior branch of the right renal artery attached to the multiple aneurysms and directly drained into the IVC, which was diagnosed as an aneurysmal-type renal AVM. Because there were no arteries arising from the aneurysms in the right renal artery, which fed the renal parenchyma, embolization of only the inflow artery was performed. For both patients, renal blood flow was maintained without any decrease of the renal function. In these patients, although renin-angiotensin system activity was within the normal range, and blood pressure became better controlled postoperatively. In addition, there was significant improvement in the brain natriuretic peptide (BNP) levels postoperatively. Thus, we believe that unstable hypertension and/or high-output heart failure as well as the aneurysmal size should be assessed in the management of renal AVMs.

A 53-year-old man presented with a painful, non-healing ischemic ulcer of the left fifth toe. The patient was initially treated conservatively for 4 months with local debridement and medication with antiplatelet therapy but his symptoms and the ulcer was refractory. A computed tomography revealed a bulky, irregular, gritty, localized calcification of the infra-renal aorta and was compatible with the so-called “coral reef aorta”. Angiography confirmed the findings of the CT scan, and there was no evidence of occlusive lesions in the distal runoff vessels. A diagnosis of blue toe syndrome secondary to infra-renal coral reef aorta was made. In order to prevent further embolization, the patient underwent aortic excision with PTFE grafting via a retroperitoneal incision. In order to increase the microcirculation of the toe and to aid in the healing of the ulcer, a lumbar sympathectomy was performed simultaneously. The ulcer healed completely on postoperative day 47. The treatment method for coral reef aorta depends on the presence or absence of global ischemia of the lower extremity and embolic complications.