Segmental arterial mediolysis with a ruptured visceral artery on two consecutive days

BACKGROUND: We describe a case of segmental arterial mediolysis in which a vessel ruptured on two consecutive days. CASE PRESENTATION: A 69‐year‐old man presented with sudden‐onset abdominal pain. Computed tomography showed a hematoma in the gastric wall. The patient was discharged after the pain was relieved but returned 8 h later with abdominal pain and shock. Repeated computed tomography revealed a massive intra‐abdominal hemorrhage without previous aneurysm formation. Emergency angiography and coil embolization were successfully carried out. Segmental arterial mediolysis was diagnosed after irregular vasodilated lesions were observed in multiple arteries. CONCLUSION: This case suggests that accurately predicting the next vessel rupture is difficult. For patients experiencing intra‐abdominal bleeding with segmental arterial mediolysis, we suggest treating only ruptured aneurysms and closely following‐up unruptured aneurysms.