Isolated Superior Mesenteric Artery Dissection: A Novel Etiology and a Review

Abstract

Isolated superior mesenteric artery dissection (ISMAD) is a rare pathology with multifactorial etiology. The aim of this article is to provide a narrative review of the latest literature about ISMAD. Case reports, series, and recent meta-analyses were included. This review is introduced with a brief case report of a rare etiology of ISMAD, followed by a discussion of its etiology, clinical presentation, diagnosis, classification, and treatment, and we report a new cause of ISMAD, that is, blunt abdominal trauma. The etiology of ISMAD is multifactorial, consisting of anatomic, genetic, and systemic components. ISMAD is more common among middle-aged males and in East Asia. Its clinical presentation ranges from asymptomatic to mesenteric ischemia, albeit mortality remains <1%. It is diagnosed and classified mostly by computed tomography angiography, and there are five classification systems for ISMAD, though traumatic etiology may be added. The treatment of ISMAD is mostly conservative, with a success rate exceeding 90%. Endovascular stenting is second line, reserved so far for failed medical management, though its role is expanding to include earlier management of symptomatic patients, while open surgical repair is left for acute mesenteric ischemia with bowel compromise.

Secondary Hemorrhagic Shock Due to Spontaneous Isolated Dissection of the Superior Mesenteric Artery Branch

“…SIDSMA is a rare and often underdiagnosed condition that primarily affects men in their fifth decade of life [ 1 , 2 ]. The first case of SIDSMA was described in 1947 by Bauersfel.…”

“…Other risk factors include male gender, hypertension, and tobacco use. SIDSMA has also been associated with vascular diseases such as fibromuscular dysplasia, medial degeneration, and colorectal and gastric cancers [ 2 ]. Another frequently mentioned cofactor is an increased angle between the superior mesenteric artery and the distal aorta (>70°), which has been linked to a more symptomatic presentation [ 3 ].…”

“…Dissection, characterized by a tear in the tunica intima and internal elastic lamina resulting in the formation of a parallel false lumen, is considered isolated when the tear does not originate from the aorta or another arterial trunk and is classified as spontaneous in the absence of an identified cause. The dissection of the superior mesenteric artery typically occurs 1 to 3 cm distal to its origin, where anterior wall shear stress is high due to the curvature the artery forms, transitioning from a static retroperitoneal position to a mobile segment [ 2 , 4 ].…”

“…Clinical presentations vary from asymptomatic to acute abdomen, with rare occurrences of complications such as hemorrhagic shock. Reported risk factors include hypertension, other hemodynamic abnormalities, smoking, and genetic components [ 2 , 3 ]. With the wide availability of CT scanning for evaluating abdominal pain, an increasing number of cases are likely to be diagnosed and reported.…”

Diagnostic Role of MDCT in Acute Mesenteric Ischemia

“…Mesenteric ischemia in SMA dissection occurs when critical luminal stenosis or occlusion by false lumen thrombosis determines vessel occlusion and consequent bowel involvement [50]. CT findings of SMA dissection are focal dilation, intimal flap, intramural hematoma, false lumen thrombosis, increased fat attenuation around the SMA, and mesenteric hematoma (Figure 5) [51,52]. Rarely, large vessels mesenteric arteritis can develop mesenteric ischemia as a devastating complication when parietal inflammation produces critical luminal stenosis or occlusion, presenting acutely and often requiring resection [53].…”