Chronic mesenteric ischemia due to SMA atherosclerotic thrombosis

Clinical History

An 85-year-old female patient was admitted to our hospital after sudden development of severe abdominal pain and distension. Past medical history includes congestive cardiac failure, atrial fibrillation, chronic renal failure and diabetes mellitus. The patient also complained of abdominal pain postprandially during previous months.

Imaging Findings

Plain X-ray abdominal demonstrated dilated bowel loops, without signs of obstruction. Urgent abdominal MDCT performed without intravenous contrast material administration due to chronic renal failure, demonstrated extensive portomesenteric venous gas, intestinal pneumatosis and free intraperitoneal air. Imaging findings were compatible with mesenteric ischaemia.
Furthermore, the origin of superior mesenteric artery (SMA) was almost completely calcified.
Emergency surgical exploration revealed small bowel ischaemia and necrosis as well as atherosclerotic thrombosis of SMA. Small bowel resection and jejunum-transverse colon anastomosis were performed. The patient died after 15 days.

Discussion

Chronic mesenteric ischaemia (CMI) is a rare disease. Patients typically present with a protracted course of vague abdominal symptoms and profound weight loss, leading to a delay in diagnosis [1]. Abdominal pain can occur postprandially in patients with occlusive mesenteric vascular disease, due to insufficient increase in blood flow. CMI is often mistaken for peptic ulcer disease, cholecystitis, liver disease, diverticular disease and malignancy. The slowly progressive development of postprandial epigastric pain associated with weight loss in an elderly patient (especially if other known atherosclerotic conditions are present) is strongly suspicious for insufficiency of the splachnic arterial supply to the bowel.
It occurs in patients with advanced atherosclerosis, and is associated with atherosclerotic risk factors such as smoking, hypertension, cerebrovascular disease and coronary artery disease [1]. Other nonatheromatous conditions include Takayasu arteritis, dysplastic lesions, and thromboangiitis obliterans, among others [2]. Unlike other ischaemic diseases, CMI is more often in females, with a 3:1 ratio of women to men. In most patients, two or more visceral arteries are involved [1]. In our case, however, only the SMA was affected. The SMA is most commonly affected in up to 90% of the patients.
The diagnostic approach is aimed at identifying atherosclerotic obstruction at the origin of the celiac trunk, SMA and IMA.
Abdominal MDCT has been proven useful for detecting atherosclerotic thrombosis of splachnic vessels and other signs of mesenteric infarction, like portomesenteric venous gas, pneumatosis intestinalis and free intraperitoneal air.
The combination of intestinal pneumatosis and portomesenteric venous gas is strongly associated with bowel ischaemia and necrosis, whereas mortality rate exceeds 70% [3]. If untreated, CMI progresses to bowel infarction, which has a poor prognosis.
The imaging findings combined with the medical history and the clinical symptoms establish the diagnosis of CMI.

Differential Diagnosis List

Final Diagnosis

Chronic mesenteric ischaemia due to superior mesenteric artery atherosclerotic thrombosis.

URL:	https://www.eurorad.org/case/9452
DOI:	10.1594/EURORAD/CASE.9452
ISSN:	1563-4086