Evolution of spontaneous dissecting mycotic Superior Mesenteric aneurysm in a 12-year-old child: A case report

Abstract

Visceral artery aneurysms are uncommon especially in children. One of the main complications before surgery is rupture. This 12-year-old child presented with a large, fast growing, mycotic superior mesenteric aneurysm that had all the favourable conditions for rupture. There was spontaneous dissection of the weakened media with partial erosion of the aneurysm into the wall of the third part of the duodenum. However, this aneurysm formed a thrombus that gradually occluded the lumen. This led to formation of collateral vessels for the continued vascular supply of the midgut. The uniqueness of this case report has been highlighted from several points (the rarity of the condition in children, the favorability of the conditions to rupture, the gradual but complete luminal occlusion with the eventual formation of collaterals to supply the midgut, and the spontaneous medial dissection with partial duodenal wall erosion without causing rupture). Although there is no standard surgical approach, early elective surgery is recommended. Nonoperative approach is an option that should aim at reducing the risk for rupture. Control of blood pressure is key. This child underwent surgery. Under total vascular exclusion, the aneurysm was opened. After total luminal occlusion and collateral blood supply to midgut was noted, infected thrombus was evacuated and the aneurysm walls debrided.