Inferior mesenteric artery aneurysm

Last revised by Craig Hacking on 2 Aug 2021

Citation, DOI, disclosures and article data

Citation:

Tatco V, Hacking C, Bell D, et al. Inferior mesenteric artery aneurysm. Reference article, Radiopaedia.org (Accessed on 24 Apr 2024) https://doi.org/10.53347/rID-45949

DOI:

https://doi.org/10.53347/rID-45949

Permalink:

https://radiopaedia.org/articles/45949

rID:

45949

Article created:

14 Jun 2016, Vincent Tatco

Disclosures:

At the time the article was created Vincent Tatco had no recorded disclosures.

View Vincent Tatco's current disclosures

Last revised:

2 Aug 2021, Craig Hacking ◉ ◈

Disclosures:

At the time the article was last revised Craig Hacking had no recorded disclosures.

View Craig Hacking's current disclosures

Revisions:

6 times, by 5 contributors - see full revision history and disclosures

Systems:

Vascular

Tags:

cases

Synonyms:

Inferior mesenteric artery aneurysms
IMA aneurysms
IMA aneurysm

Inferior mesenteric artery aneurysms are among the rarest of all visceral artery aneurysms.

Most patients with IMA aneurysms are asymptomatic and these aneurysms are usually discovered incidentally ^3-6. Some patients may present with a palpable pulsatile abdominal mass or bruit around the umbilicus ^3,6. In cases complicated by rupture, patient may present with abdominal pain, low back pain, collapse or hemorrhagic shock ³.

Pathology

Atherosclerotic disease is the most common cause of aneurysmal dilatation of the IMA ^3-6. These aneurysms usually occur in the presence of chronic stenosis or occlusion of either or both the celiac artery and superior mesenteric artery (SMA). The IMA becomes part of the collateral formation through the arc of Riolan or marginal artery of Drummond resulting in increased intraluminal flow. The increased flow in combination with atherosclerotic disease can lead to arterial wall weakness and subsequent formation of aneurysms.

Other causes include ^3-6:

Radiographic features

Ultrasound

Ultrasound with Doppler may show IMA aneurysms as dilated vessels lying parallel to the lower part of the abdominal aorta ⁴.

Angiography: CTA/MRA/DSA

IMA aneurysms are best visualized by arterial imaging like CT angiography (CTA), MR angiography (MRA) and digital subtraction angiography (DSA). These aneurysms can be saccular or fusiform (commonly pear-shaped) in morphology. Associated stenosis or occlusion of the celiac artery and SMA as well as the collateral vessels (e.g. arc of Riolan and marginal artery of Drummond) can also be demonstrated.

Treatment and prognosis

Surgical treatment by way of revascularization with reimplantation of the resected IMA along with either angioplasty or bypass of the stenosed or occluded celiac and SMA seem to be the best way to prevent death from rupture ^1-6. It is suggested that if an aneurysm is >2 cm at the proximal IMA or >1 cm at the distal IMA, surgical intervention should be performed due to an increased risk of rupture ³. If an IMA aneurysm ruptures, prognosis is poor ^3-6.