Intracystic arteries in a chronic pancreatic pseudocyst.

BACKGROUND: An enlarging pancreatic pseudocyst can incorporate adjacent vessels into its wall, leading to pseudoaneurysm formation in the presence of proteolytic enzymes. Intact arteries running through the cyst cavity are very rare, however. CASE OUTLINE: A 54-year-old man with a chronic pancreatic pseudocyst (15 cm diameter) underwent internal drainage by means of cystjejunostomy Roux-en-Y. Two large pulsating arteries running through the cyst cavity were identified as the middle colic artery and one of its branches. Temporary clamping of the transcystic arteries revealed no signs of ischaemia in the transverse colon, so the vessels were ligated and the cystjejunostomy completed. The patient remains well one year later. DISCUSSION: Bleeding following internal drainage procedures carries a higher mortality rate than spontaneous bleeding in chronic pancreatic pseudocysts but is easier to prevent.This case highlights the importance of thorough exploration of the pseudocyst to identify any vessels in its cavity or wall.