Clinically Suspected Segmental Arterial Mediolysis of the Splanchnic Arteries: A Report of 2 Rare Cases

Abstract

BACKGROUND Segmental arterial mediolysis (SAM) is an uncommon vascular pathology characterized by arteriopathy, mainly of medium-sized abdominal splanchnic vessels, without an atherosclerotic, inflammatory, infectious, or autoimmune underlying etiology. Segmental arterial mediolysis is clinically heterogeneous and symptoms may be completely nonspecific. The knowledge of radiological features of segmental arterial mediolysis and the exclusion of other pathologies should direct early diagnosis and refer patients for correct treatment. CASE REPORT In the last 2 years, we treated 2 different adult patients (an 89-year-old woman and a 52-year-old man) with spontaneous visceral bleeding, admitted to the Emergency Department due to acute onset of abdominal pain, anemia, and computed tomographic angiography (CTA) evidence of aneurysmatic, and stenotic alterations of splanchnic arteries. Based on clinical, laboratory, and radiological features, segmental arterial mediolysis was suspected. These 2 patients were referred to our Interventional Radiology Department and treated with super-selective transcatheter arterial embolization (TAE), performed by a minimally invasive approach, allowing an immediate clinical improvement with regression of symptoms and avoiding major surgical treatment. CONCLUSIONS In patients with clinical, laboratory, and radiological signs of acute and/or chronic abdominal bleeding and radiological findings suggesting segmental arterial mediolysis, mini-invasive endovascular treatment is a safe, extremely reliable, and secure procedure and appears to be the first-choice treatment when available. Since abdominal bleeding could have fatal consequences in these patients, timely diagnosis and endovascular therapy are essential to treat visceral vascular alterations due to segmental arterial mediolysis.

Figure 1.

Case 1. (A–C) Coronal-CT, three-dimensional reconstruction, and axial-CT images show pseudoaneurysmatic dilatations involved a distal branch of the splenic artery (white arrow) with an axial dimension of 6 mm. (D) Coronal-CT image after angiographic treatment with coil embolization reveals the presence of an area of infarction in the upper pole of the spleen, without clinical and laboratory sequelae.

Figure 2.

Case 1. (A–D) Multiplanar-CT reconstructions (MPR) show multiple alterations of splanchnic vessels, such as a right renal artery mimic a fibromuscular dysplasia aspect (open arrow in A), a ‘string of beads’ appearance of the left gastric artery (white arrow in B–D), right gastroepiploic artery, and anastomotic arcades of the middle colic artery and left colic artery and ileal and jejunal branches from the superior mesenteric artery (white arrowheads).

Figure 3.

Case 1. Catheter angiogram of the splenic artery via the coeliac axis shows a distal pseudo-aneurysm marked in (A) by white arrow. (B) Catheter angiogram post-coil embolization: the pseudo-aneurysm was successfully occluded.

Figure 4.

Case 2. (A–C) Coronal-CT, three-dimensional reconstruction and axial-CT images show an inferior pancreaticoduodenal artery pseudo-aneurysm formation (white arrow) and fat stranding in the peripancreatic space, with an anatomical variant subtype consisting of an inferior pancreaticoduodenal artery (IPA) originating from an accessory right hepatic artery from the superior mesenteric artery (SMA).

Figure 5.

Case 2. (A, B) Two days later, the first embolization multiplanar-CT reconstructions (MPR) demonstrating the presence of a direct sign of bleeding (blush) from a branch of the inferior pancreaticoduodenal artery, distally to the embolized region (white arrow) with surrounding hematoma (asterisk). (C) Super-selective arteriography confirmed the pathological vessel, which was treated using another detachable micro-coil (white arrow).