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A man in his 50s with untreated hypertension presented to the emergency department with sudden-onset periumbilical pain that began 1 hour earlier. He was agitated and diaphoretic, with a blood pressure of 261/152 mm Hg and a pulse rate of 91 beats per minute. Physical examination revealed a flat soft abdomen with localised tenderness and rebound tenderness around the umbilical region. The intensity of the pain was disproportionate to the relatively mild abdominal findings, raising concern for acute mesenteric ischaemia or other acute vascular causes of abdominal pain including possible aortic pathology. Analgesia, sedation and antihypertensive therapy were initiated to stabilise the patient and facilitate further diagnostic assessment. Contrast-enhanced CT, performed approximately 1 hour after arrival (2 hours after symptom onset), revealed an intimal flap in the superior mesenteric artery (SMA), originating 2 cm from the ostium and extending to the first jejunal branch. A patent false lumen markedly compressed the true lumen ( figure 1A), with thrombotic occlusion of the mid-SMA (figure 1B), consistent with isolated superior mesenteric artery dissection (ISMAD). Extensive small-bowel non-enhancement was also noted (figure 1C), indicating impaired perfusion. Because of persistent pain and agitation, which interfered with ongoing evaluation and treatment and the need for close haemodynamic control in preparation for possible emergency surgery, endotracheal intubation was performed and mechanical ventilation was initiated 3 hours after symptom onset. Based on these findings, progressive bowel necrosis was suspected.