Rare anatomic variation of the right hepatic artery and accessory right hepatic artery supplying hepatocellular carcinoma: A case report and literature review

Variations of the Cystohepatic Blood Supply in American Midwestern Donor Cadavers

Knowledge of right hepatic artery (RHA) and cystic artery (CA) variations is crucial for surgeons performing procedures on the hepatobiliary system, pancreas, and duodenum. Commonly, the RHA originates from the superior mesenteric artery (SMA), while the CA originates from the RHA and is found within the cystic triangle during laparoscopic cholecystectomies. Here we investigated variations in the origin and path of the RHA and CA in a sample of American midwestern cadavers (n = 18) from the Gift of Body Program at A.T. Still University's Kirksville College of Osteopathic Medicine. Portal triads and associated vessels were dissected to reveal the artery pathways. The origin, branching pattern, and course of the RHA and CA were documented, and descriptive measurements were taken. We describe four cases where the RHA originated from the anterolateral proximal SMA, traveled deep to the pancreatic neck, and had a slightly variable but close relationship with the portal triad structures. The CA was present in the cystic triangle in all 18 donors, typically originating from the RHA except for one case where it originated from the left hepatic artery. In six cases, the CA originated outside of the cystic triangle, crossing either superficially or deeply to the common hepatic duct to enter the cystic triangle. Knowledge of these variations will enhance preoperative planning and the overall safety of surgical procedures in this area.

A rare hepatic artery variant reporting and a new classification

Variations of the hepatic artery are very common, but they greatly increase the difficulty of surgery and the risk of complications in perihepatic surgeries such as liver transplantation, liver segmentectomy, and gastroduodenal surgery. Thus, it is important to precisely define the type of hepatic artery variant before surgery. However, there are often rare variants that cannot be defined with existing classifications. For example, the type of hepatic artery variant in the current case could not be classified with conventional classifications, and no such variation has been reported to date, involving two accessory left hepatic arteries from the common hepatic and left inferior phrenic arteries, respectively. Based on the existing 3DCT technology and the CRL classification method, which is applicable to the most common hepatic artery variants, we reviewed many rare variant types and proposed a new classification method (ex-CRL classification) for hepatic artery variations that do not fit the classic scope. The ex-CRL classification can accurately classify the vast majority of rare cases in the literature, greatly compensates for the limitations of current hepatic artery classifications, improves the generalization and understanding of rare cases, and reduces surgical complications.

Classification of the Superior Mesenteric Artery

The aim of this study was to characterize the branching pattern and morphology of the superior mesenteric artery (SMA), and also to create a new SMA classification, which seems necessary for clinicians performing surgery in this anatomical area. The anatomical variations in the branching patterns of the SMA were examined in 30 cadavers fixed in 10% formalin. Morphometric measurements were then obtained twice by two researchers. In the proposed classification system, Type I, characterized by all normal branches - inferior pancreatoduodenal artery, ileocolic artery, right colic artery, middle colic artery and intestinal arteries - occurred in 53.33% of the specimens. Type II, characterized by absence of the inferior pancreatoduodenal artery, was present in 26.67%. Type III, characterized by absence of the right colic artery, was present in 3.33%. Type IV, characterized by a common trunk for the inferior pancreatoduodenal artery and middle colic arteries, was observed in 3.33%. Type V, characterized by an aberrant hepatic artery and absence of the inferior pancreatoduodenal artery, was observed in 13.33%. The origin of the SMA was at the Th12/L1 level in 10% of cases, at L1 in 43.33%, at L1/L2 in 36.67%, and at L2 in 10%. The SMA is characterized by high morphological variability, the variants being associated with distinct clinical aspects. The introduction of a new, structured, anatomical classification seems necessary for all clinicians.

A Rare Anatomic Variant of Double Replaced Hepatic Arteries: A Case Report and Brief Review of the Anomalous Hepatic Vasculature Literature

BACKGROUND The liver is a frequent site of surgical resection for both benign and malignant lesions. Advanced knowledge of the hepatic arterial system and its variants is crucial to avoid incidental injuries during a resection procedure. Many variants have been previously described in the literature, yet extremely rare cases continue to be encountered in clinical practice. Documentation of these variants can thus allow for proper preoperative procedural planning when considering interventions involving the liver. Our aim is to present one such unique and extremely rare anomaly. CASE REPORT During routine cadaveric dissection of a 78-year-old man who had died of acute myeloid leukemia, a rare anatomic variant of the hepatic vasculature was revealed: a replaced right hepatic artery (rRHA) coming directly from the celiac trunk, a middle hepatic artery (MHA) continuing from the common hepatic artery (CHA), and a replaced left hepatic artery (rLHA) branching from the left gastric artery (LGA). To the best of our knowledge, this anomaly has only been described once before in the literature. CONCLUSIONS We report a rare anatomical variant of the hepatic vasculature. The significance of this variant must be considered during preoperative planning and the intra-arterial infusion of targeted drugs. This case further emphasizes the importance of proper medical imaging and documentation to ensure the best course of treatment for each patient. Given that this variant has only so far been identified in 2 post-mortem subjects, further work should include attempts at characterizing its physiologic effects in a living patient.

Unusual development of the celiac trunk and its clinical significance

We describe a case of unusual development of the celiac trunk observed in the cadaver of 1-year old male child. The celiac trunk branched into five vessels: the splenic, common hepatic and left gastric arteries, the left inferior diaphragmatic artery, and a short trunk that branched into the right inferior diaphragmatic artery and right accessory hepatic artery. Additionally, the manner of branching of the vessel was unusual: it was possible to distinguish two branching points that corresponded to its s-shaped trajectory. There were also other variations of vascular supply, such as the presence of a left accessory hepatic artery, an additional superior pancreatoduodenal artery, and others. It should be noted that multiple developmental variations can be common in clinical practice and clinicians should be aware of them during diagnostic and interventional procedures.

Two novel hepatic arterial variations in a living liver donor detected by multidetector computed tomography angiography

PURPOSE

Considering that the knowledge of variations in the hepatic vascular structure is essential for hepatic surgery and liver transplantation, we aimed to present a rare case of the anatomic variation of arterial blood supply to the liver to help prevent complications and choose suitable donors.

METHODS

We present a novel variant in this case report (living liver donor), an accessory right hepatic artery (supplying segment 6) originating from the dorsal pancreatic artery and a middle hepatic artery (supplying segment 4) arising from the pancreaticoduodenal artery (first branch of the gastroduodenal artery). Preoperative diagnosis was made using computed tomography angiography (CTA) with multiplanar reformate (MPR) images, curved planar reformate (CPR), maximum intensity projection (MIP) images and three-dimensional volume renderings (3D VR).

RESULTS

To the best of our knowledge, this is the first case in the English literature describing this type of variation. A search for new donors began since the living liver donor was not suitable due to the very thin segment 4 artery, posing potential risks for the donor and the thin segment 6 artery being a complicating factor for anastomosis.

CONCLUSIONS

The preoperative knowledge of liver blood supply has great importance in planning surgery and transplantation. CTA, reformate and reconstruction techniques allow for the evaluation of difficult and complex anatomic variations.

Rare combined variations of accessory left hepatic artery and accessory right hepatic artery: a case report and literature review

Variations in the hepatic artery are commonly described in the literature, which is vital for the success procedure of all hepatobiliary surgery. Usually a variation occurs in either the accessory right hepatic artery (aRHA) or the accessory left hepatic artery (aLHA). However, we report an extremely rare case where the variation occurs in both simultaneously. We over served the aRHA arising from the gastroduodenal artery and branching into the superior pancreatic duodenum artery, while the aLHA arose from the common hepatic artery and branched into right gastric artery. This situation has never been reported in literature. We will discuss the meaning of this hepatic artery variation in a clinical setting.

Accessory right hepatic artery originating from proximal and distal right renal artery in two subjects

The hepatic arteries are known for aberrant origins and course. The following two-case report discusses the unique origin of accessory right hepatic artery from proximal and distal right renal arteries, respectively, its clinical significance, and the importance of a preoperative angiogram in renal and liver surgeries involving vascular control.

An accessory right hepatic artery derived from the superior mesenteric artery for anterior right liver lobe supply: a case report

PURPOSE

During the last decades, it has been established that there are numerous individual anatomical variations of the arterial blood supply in human liver. In the present study, we examined the liver vascularization of an intrahepatic cholangiocarcinoma patient.

METHODS

For surgical planning, an enhanced CT scan was performed and a three-dimensional model of liver vascularization constructed.

RESULTS

The patient was diagnosed as a Michel's type VII hepatic artery variation. An accessory right hepatic artery arose from the superior mesenteric artery and had distributed into the right anterior liver to provide the blood supply of segments V and VIII, which was more medial than the territory of the right hepatic artery coming from the proper hepatic artery. At the same time, an accessory left hepatic artery originated from the left gastric artery.

CONCLUSION

We present a case in which an accessory right hepatic artery provided a territory more medial than a right hepatic artery coming from the proper right artery.