BACKGROUND: Median arcuate ligament syndrome (MALS) can compromise hepatic arterial flow during pancreaticoduodenectomy, particularly in the context of celiac artery stenosis. Although collateral pathways are often relied upon, their efficacy can be unpredictable.

CASE REPORT: A 68-year-old man with a history of sick sinus syndrome and pacemaker placement was referred for evaluation of a branch duct-type intraductal papillary mucinous neoplasm that had demonstrated a mural nodule (7 mm in size) during 4 years of surveillance. Given the presence of high-risk stigmata, pancreaticoduodenectomy was performed. Preoperative computed tomography imaging revealed collateral circulation between the dorsal pancreatic artery (originating from the splenic artery) and the inferior pancreaticoduodenal artery, which was preserved intraoperatively. However, after specimen removal and before reconstruction, hepatic arterial pulsation was no longer palpable. Release of the median arcuate ligament promptly restored pulsatile flow. The postoperative course was complicated by wound dehiscence on postoperative day 13, requiring fascial resuturing. The patient was discharged uneventfully on postoperative day 19.

CONCLUSIONS: This case demonstrates that even anatomically preserved collateral pathways can be insufficient to maintain hepatic arterial flow intraoperatively in patients with MALS, underscoring the importance of dynamic flow assessment and the use of ligament release when indicated.

Keywords: Collateral Circulation, Hepatic Artery, median arcuate ligament syndrome, Pancreaticoduodenectomy