# Idiopathic Inflammatory Superior Mesenteric Artery Aneurysm: Case Report and Systematic Literature Review

## TL;DR

This paper reports a rare case of idiopathic inflammatory SMA aneurysm and finds only two similar cases in the literature, highlighting the challenges in diagnosis and treatment.

## Contribution

The paper presents a new case of idiopathic inflammatory SMA aneurysm and a systematic review showing its rarity.

## Key findings

- A 61-year-old patient with idiopathic inflammatory SMAA was successfully treated with fenestrated endograft implantation.
- A systematic review found only two other reported cases of idiopathic inflammatory SMAA.
- PET-CT confirmed the inflammatory nature of the aneurysm and aided in treatment planning.

## Abstract

Superior mesenteric artery aneurysm (SMAA) is a rare presentation mostly secondary to atherosclerosis, infection, cystic medial dysplasia, collagen vascular disorders, trauma, and arterial dissection. However, inflammatory SMAAs are sometimes idiopathic. The aim of the article is to report the case of an idiopathic inflammatory SMAA and perform a systematic literature review.

A 61 year old man presented with chronic abdominal pain. Computed tomography angiography showed a typical 65 mm diameter inflammatory abdominal aortic aneurysm and a SMAA with similar signs of wall inflammation. Positron emission tomography computed tomography confirmed the inflammation by active fixation. A full workup including all inflammatory markers was negative, and no cause was found. Treatment consisted of fenestrated endograft implantation. At 11 months, follow up confirmed aneurysm exclusion and patency of the stents and a similar SMAA diameter with some mild remaining inflammation.

A systematic review of the MEDLINE and PubMed databases extending from 1979 to 2024 by a combined strategy of Medical Subject Headings terms returned only two publications of idiopathic inflammatory SMAA in two patients. In both cases, the symptoms were abdominal or lower back pain and the diagnosis was made by computed tomography angiography. Treatment was open surgery in one case and medical in the other. Median follow up was 18 months.

Idiopathic inflammatory SMAA is rarely described in the literature. The aetiological assessment including histological data should be exhaustive in order not to miss a differential diagnosis.

•Rare idiopathic inflammatory SMA aneurysm successfully managed by FEVAR.•Systematic review identified only two similar idiopathic inflammatory SMA cases.•PET-CT helped confirm inflammatory nature and guide treatment strategy.•Endovascular repair maintained patency with stable imaging at 11 months.

Rare idiopathic inflammatory SMA aneurysm successfully managed by FEVAR.

Systematic review identified only two similar idiopathic inflammatory SMA cases.

PET-CT helped confirm inflammatory nature and guide treatment strategy.

Endovascular repair maintained patency with stable imaging at 11 months.