Replaced common hepatic artery from left gastric artery during pancreatico‐duodenectomy; insight holds the key

A 47-years-old female presented with progressive obstructive jaundice. Cross sectional imaging showed a 17×19×19.2 mm enhancing mass at the ampulla. The replaced common hepatic artery(CHA) was originating from the left gastric artery(LGA) (Fig. 1). She underwent biliary drainage to address cholangitis, and subsequently planned for pancreatico-duodenectomy. Intra-operatively, there was no artery palpated along the upper border of the pancreas. The CHA was originating from the LGA, and coursing along the lesser omentum. At the hilum, the gastro-duodenal artery(GDA) was originating from the CHA, and was coursing along the medial border of the hepatoduodenal ligament(HDL) before traversing into the pancreatic parenchyma (Fig. 2).The GDA was divided at its origin at the hepatic hilum. The intra-operative period was uneventful. She was discharged in a satisfactory condition on post-operative day 14. The classic anatomy of hepatic artery is found only in 55%–60% of the population. The variations of left and right hepatic artery are common but that of the CHA is rare, which includes its origin from aorta(2%), SMA(2%), and the celiomesenteric trunk. The origin of the CHA from the LGA, which corresponds to Michels type X and Hiatt type VI arterial anomaly, is extremely uncommon(0.5%).1, 2 Song et al. described eight cases of the replaced CHA from LGA, all passing through the fissure of the ligamentum venosum, as in the indexed case.3 This unusual course may lead to injury of the CHA, which can lead to biliary anastomotic leak, strictures, hepatic ischemia, and mortality.4 There is sparse data on the replaced CHA from the LGA.5 The surgeon should be aware of this anomaly in the preoperative imaging itself. If not revealed beforehand, the CHA would not be found at the pancreatic upper border. Rather, an artery coursing along the HDL would be found between the pancreatic head and the hepatic hilum. This would create a great amount of intra-operative confusion as to whether this is the replaced common hepatic artery from the SMA traversing through the pancreatic parenchyma. Whereas, this single artery along HDL is actually the GDA originating from the replaced CHA, at the level of the hepatic hilum, and coursing downwards. This may compel the surgeon to abandon the procedure as well. This anomaly is crucial in other surgical procedures as well. During gastrectomy, the LGA should be ligated after the origin of the hepatic artery to avoid hepatic ischemia. During left hepatectomy, it can be disastrous if the CHA is ligated at the gastrohepatic ligament, assuming it to be the LHA.6 López-Andújar et al reported importance of this anomaly in settings of cadaveric liver transplantation, where hepatic artery reconstruction remains the most crucial part.7 Pre-operative CT with angiogram plays a key role in detecting this rare anomaly with its unusual course.8 The GDA can be divided just below its origin at the hepatic hilum. It's always preferable to apply a vascular clamp to this unusual course of the GDA at the medial border of the HDL, and feel the absence of the pulsations caudally. To the best of our knowledge, this is the first reported case of replaced CHA originating from the LGA, encountered during pancreaticoduodenectomy. This anomaly should always be kept in the mind while going through the preoperative cross-sectional imaging, to avoid intraoperative chaos and confusion. Sunita Gupta: Conceptualization; visualization; writing – original draft. Sri Hari Priya Vemulakonda: Data curation; methodology; writing – original draft. Spruha Punati: Conceptualization; methodology; visualization. Tara Prasad Tripathy: Visualization; writing – original draft; writing – review and editing. Ranjan Kumar Patel: Methodology; supervision; writing – review and editing. Tanmay Dutta: Data curation; methodology; visualization. Bramhadatta Pattnaik: Conceptualization; methodology; writing – review and editing.