•Vincent

Title: Longitudinal management of Segmental Arterial Mediolysis complicating chronic mesenteric ischemia, a case report

Body:

Segmental Arterial Mediolysis (SAM) is a rare, non-atherosclerotic, non-inflammatory arterial vasculopathy of stenosis and/or aneurysm. SAM has been documented throughout the arterial system yet predominantly impacts the splanchnic arteries, often manifesting as mesenteric ischemia. There are no clinical guidelines for the treatment of SAM. Here we present the longitudinal care of a patient with chronic mesenteric ischemia complicated by SAM, highlighting the presentation and potential compilations of this disease process along with their management.

The patient initially presented as a 69 yo F with abdominal pain. Her imaging demonstrated multiple aneurysms throughout her proximal and distal visceral vessels, including notably her GDA (2.0 cm, thrombosed), middle colic (1.8 cm, patent), and splenic arteries (1.4 cm, partially thrombosed). She had occlusion of her celiac and SMA arteries, with a large collateral meandering mesenteric artery extending through the middle colic to the GDA. She was diagnosed with acute on chronic mesenteric ischemia and taken for percutaneous stenting. This was unsuccessful, and therefore ROMS was performed. During the laparotomy, she was incidentally noted to have a jejunal mass, which was resected. She tolerated the procedures without incident and had significant improvement in her pain. She was discharged home on postoperative day 6.

At her 6 week postoperative visit, mesenteric duplex demonstrated stent occlusion and her symptoms had returned. She was scheduled for an open bypass. Supra-celiac to common hepatic and SMA bypass was performed without issue. Given the size of the middle colic aneurysm, the decision was made to exclude it. However it was part of the collateral circulation from MMA to GDA. Therefore, it was double clipped and then the feeding MMA and GDA collaterals were ligated. These were then anastomosed to each other, totally excluding the aneurysm. She recovered uneventfully and was discharged on postoperative day 13.

At her 9 month follow up, she was noted to have thrombosis of the SMA bypass with narrowing of the hepatic bypass. Despite this, she remained largely asymptomatic and was gaining weight. The decision was made to prophylactically treat the hepatic narrowing to avoid complete shutdown. She was taken to the angiography suite and underwent successful angioplasty of the stenosis with 4, 5, and 6 mm balloons. Given the concern for SAM playing a role in the genesis of stenosis, a Lutonix paclitaxel DCB was used as well. She tolerated the procedure. On 1 month follow up, she remains symptom free while gaining weight.

Here we presented a unique presentation of chronic mesenteric ischemia complicated by the presence of SAM, as well as the longitudinal management of such.

Relevant history:

Cachectic and frail appearing

Relevant test results:

CT scan demonstrating multiple visceral aneurysms

Teaching points:

SAM is an rare condition that can complicate intra-abdominal vascular disease