Replaced common hepatic artery from the superior mesenteric artery: multidetector computed tomography (MDCT) classification focused on pancreatic penetration and the course of travel

A Robotic Pancreaticoduodenectomy Case Involving a Meandering Main Pancreatic Duct Coursing Posterior to a Replaced Common Hepatic Artery and in Front of the Portal Vein

INTRODUCTION

Anatomical anomalies, such as branches of the celiac artery and superior mesenteric artery (SMA), and pancreatic malformations, including the annular pancreas, are important during pancreaticoduodenectomy (PD). Here, we report a case of an anomaly of the artery and main pancreatic duct (MPD) in which the pancreatic parenchyma surrounded the replaced common hepatic artery (rCHA), and the meandering main pancreatic duct (MMPD) ran behind the rCHA.

CASE PRESENTATION

A 71-year-old woman was diagnosed with intraductal papillary mucinous neoplasm (IPMN) of pancreatic body and the dilation of MPD to 13 mm, which was a factor of high-risk stigmata. Preoperative computed tomography (CT) showed that the rCHA branched from the superior mesenteric artery (SMA) and the pancreatic parenchyma surrounded the rCHA. Moreover, the MPD meandered and ran behind the rCHA. PD was performed. At the time of dissection between the rCHA and pancreatic parenchyma, we had to divide not only the cranial part of the pancreatic parenchyma along the rCHA but also the MPD. The postoperative course was uneventful.

CONCLUSION

This is the first report of the rCHA surrounded by pancreatic parenchyma and MMPD running behind the rCHA and in front of the portal vein.

Unraveling a Rare Case of Pediatric Solid Pseudopapillary Neoplasm With a Replaced Common Hepatic Artery Arising From the Superior Mesenteric Artery

Pancreatic solid pseudopapillary epithelial neoplasm (SPEN) is a rare pancreatic tumor with low-grade malignant potential. They often present in young women in their second and third decade of life, with only a small minority concerning children. It has a good prognosis, with a five-year survival rate of up to 97%. A common hepatic artery (CHA) arising from the superior mesenteric artery (SMA) is a rare occurrence. A 12-year-old girl, admitted with features of obstructive jaundice, was evaluated to have a heterogeneously enhancing mass lesion of size 7.5 × 7.2 cm involving the head of the pancreas on contrast-enhanced CT of the abdomen (CECT). CT angiogram showed a CHA trunk arising from the SMA and a type V hepatic arterial variation. Whipple's pancreaticoduodenectomy was done for the patient, and the postoperative period was uneventful. The subsequent histopathology report was confirmatory for SPEN, with an R0 margin of resection. SPENs of the pancreas are extremely rare, and after surgical resection, they often have an excellent long-term prognosis. Variations in hepatic artery anatomy, as in this case, need meticulous dissection to avoid inadvertent vascular insult.

Clinical Consideration of Anatomical Variations in the Common Hepatic Arteries: An Analysis Using MDCT Angiography

PURPOSE

The purpose of this study was to determine the prevalence of normal hepatic vascularization and variations in the common hepatic arteries using multidetector computer tomography angiography. These variants should be acknowledged before any surgery of the upper abdomen. The aim of our work was to analyze the variations in the hepatic arteries and their possible clinical and surgical implications.

MATERIALS AND METHODS

This study was carried out on 4192 patients who underwent 64-slice MDCT angiography, from August 2015 to December 2021. We used surface and volume-rendering techniques in order to post-process images of the vascular components in the desired area.

RESULTS

We highlighted 76 cases with replaced common hepatic arteries, which are characterized by the origin of the common hepatic artery trunk located outside the classical composition of the celiac trunk. We identified three levels of origin: the abdominal aorta, the superior mesenteric artery and the left gastric artery. We observed six different aspects of the morphological variability of the celiac trunk and the superior mesenteric artery. The trajectory of the artery trunk, between the aortic origin and the hepatic pedicle portion of the hepatic portal vein, is variable and we analyzed the pancreatic trajectory accordingly.

CONCLUSIONS

The prevalence of hepatic arterial variants found during this study was similar to that in other specialized studies. We came across variants that have not been described in the well-known classification of Michels and even described extremely rare variations. The study of abnormal hepatic vascularization plays an important role in the surgical planning of hepatic transplantation, liver and pancreatic resection and extrahepatic upper abdominal surgeries.

Anatomical variations of the hepatic artery in it's extra hepatic journey: a cadaveric study with its clinical implications

Vascular anomalies are a serendipitous finding during surgeries and diagnostic angiography. Such variations are frequently encountered in the abdominal region. These anomalies are usually asymptomatic but the presence of hepatic arterial variations may lead to injuries of the liver during surgery. The present study was conducted on 35 adult embalmed cadavers, 31 males, 4 females from August 2015 to December 2021 in the Department of Anatomy, Amrita School of Medicine, Amrita Institute of Medical Sciences, Kochi. In this study of 35 cadavers, we present 3 variants: an accessory right hepatic artery, replaced common hepatic artery, replaced common hepatic artery anastomosis with accessory left hepatic artery and an arc of Buhler. One of our variants has not yielded a precedent in literature search. We have compared these variants with Michels and Hiatt classification. It is known that different variants arise at distinct stages of embryonic development. As specialists in anatomy, we have tried to correlate the variants in our study with their embryological origins.

CT reporting of relevant vascular variations and its implication in pancreatoduodenectomy

Pancreatoduodenectomy (PD) also known as Whipple procedure is done for malignant lesions involving the distal CBD, duodenum, ampulla and pancreatic head. In the absence of peritoneal and distant metastases, resectability of the lesion is mainly determined by the relationship of the lesion with the vascular structures in the vicinity. Vascular variations of the celiac artery branches are common and PD, a complex surgical procedure, becomes more challenging if the vascular variations are present. In borderline resectable lesions advances in neoadjuvant therapies and refined surgical techniques are pushing the boundaries of resection. Extended PD is done in borderline resectable lesions when resection and reconstruction of portal vein involved by the primary mass and dissection of extended lymph nodal stations are intended. In this era where more borderline cases are undergoing surgery, it is essential for the radiologist to understand the procedure and the implications of variations in vascular anatomy. Though there are many radiology literatures available on the diagnostic and resectability criteria related to normal vessel anatomy there are very few on the importance of the variant arterial anatomy. The purpose of this review is to familiarize the readers with these variant vessels which can help the surgeons in their intraoperative identification and consequently improve surgical outcomes.