Superior mesenteric artery dissection with aneurysm, hematoma, and bowel ischemia mimicking pancreatitis: a rare case...

Superior mesenteric artery (SMA) dissection is an uncommon yet potentially fatal vascular condition that often manifests as acute abdominal pain complicates the diagnostic process. Contrast-enhanced CT is essential for diagnosis, revealing the extent of dissection and associated complications such as thrombosis or aneurysm.

We report a case of a 58-year-old male presenting with right hypochondriac and epigastric pain, accompanied by vomiting. Laboratory tests showed leukocytosis, elevated amylase and lipase, and a falling hemoglobin level, leading to a preliminary diagnosis of acute pancreatitis and initiation of supportive management. Persistent pain and progressive decline in hemoglobin prompted a contrast-enhanced CT, which revealed an isolated superior mesenteric artery dissection with a partially thrombosed false lumen, small pseudoaneurysmal dilation, and a significant intraperitoneal hematoma. Bowel wall thickening in the distal jejunum and proximal ileum suggested ischemia or early necrosis, with associated mild ascites and edematous bowel loops, but no pneumoperitoneum.

Isolated SMA dissection with thrombosis, aneurysm, and hematoma can closely mimic acute pancreatitis, highlighting the importance of considering vascular causes in acute abdominal pain. Early use of contrast-enhanced CT guided by clinical red flags is crucial to prevent complications such as bowel necrosis. Our case demonstrates that, in hemodynamically stable patients, conservative management with supportive care, antihypertensives, and anticoagulation can result in favorable clinical and radiologic outcomes. This case demonstrates the integration of systematic CT imaging with clinical red-flag assessment to differentiate SMA dissections requiring urgent intervention from those amenable to conservative management, potentially reducing diagnostic delays and improving outcomes.