Extensive Embolization of Splanchnic Artery Aneurysms due to Segmental Arterial Mediolysis

Segmental arterial mediolysis (SAM) is a rare non-atherosclerotic, non-inflammatory, non-infectious arteriopathy in middle-aged patients that tends to affect medium-sized splanchnic arteries typically leading to dissecting aneurysms which in case of rupture have a high mortality. Treatment options include watchful waiting and endovascular or surgical intervention. There are no official treatment guidelines and to the best of our knowledge, there has not been any report of extensive exclusion of multiple splanchnic vessel regions in affected patients to date.

We retrospectively examined the outcome of extensive splanchnic embolization in four patients suffering from SAM between 2011 and 2016 with follow-up periods of up to 7 years.

One patient presented with abdominal pain due to rupture of aneurysms of the pancreaticoduodenal arcade, one with abdominal pain due to dissection, and two were clinically asymptomatic but displayed rapidly progressing disease over the course of 12 months. All patients were treated with complete exclusion of the diseased vessel segments by coiling all branches to and from the diseased segment. In three cases the main hepatic artery was excluded completely. In one case, the complete vascular bed of the celiac axis was excluded by coiling the distal vessel branches and placing a stent graft over the orifice of the celiac trunk. During a follow-up period of a minimum of 2 and a maximum of 7 years after intervention, there were no immediate or long-term complications except for a temporary arterio-portal fistula. Interestingly, no new diseased areas of SAM were detected afterwards.

Extensive endovascular exclusion of the entire diseased arterial segment with coils seems to be a safe and effective treatment option in patients with SAM presenting with ruptured or rapidly growing aneurysms. Provided that patients have normal liver function and proper portal venous flow, risk of hepatobiliary complications seems to be low even after extensive embolization.

· An asymptomatic SAM can be followed up.. · In case of disease progression or suspicion of aneurysm rupture, an endovascular approach is indicated where the whole pathological vessel bed should be excluded with coils.. · It seems that exclusion of even extensive vessel areas is tolerated..

· Najafi A, Sheikh GT, Binkert C. Extensive Embolization of Splanchnic Artery Aneurysms due to Segmental Arterial Mediolysis. Fortschr Röntgenstr 2019; 191: 1010 - 1014.