Rare complete replacement-type left hepatic artery originating from the left gastric artery: A case report

Abstract

BACKGROUND

A complete replacement left hepatic artery (LHA) solely originating from the left gastric artery (LGA), with no supply from the hepatic artery proper, is exceptionally rare. This variant places entire left lobe perfusion on the LGA. Literature review confirms no prior reports of such an isolated LHA replacement pattern in surgical/radiological publications. Unrecognized, this anatomy carries significant intraoperative injury risk during hepatobiliary/ upper gastrointestinal surgery.

CASE SUMMARY

A 62-year-old man underwent laparoscopic radical gastrectomy with D2 Lymphadenectomy for gastric cancer. During dissection of the hepatogastric ligament, an unexpected vascular anatomy was encountered: The LHA originated exclusively from the LGA, with no conventional branch from the hepatic artery proper. Recognizing this variant artery was essential for left liver perfusion, the LGA was ligated proximally near its celiac origin while meticulously preserving blood flow through the anomalous LHA. The gastrectomy and reconstruction were completed without complication. Postoperative recovery was smooth, with serial liver function tests remaining normal, confirming preserved hepatic arterial supply.

CONCLUSION

Preoperative mapping detected a critical aberrant left hepatic artery; its preservation prevented liver ischemia, ensured safety.

Key Words: Gastric cancer; Left hepatic artery; Left gastric artery; Vascularvariation; Case report

Core Tip: This case report underscores the critical importance of preoperatively clarifying hepatic vascular variations for surgical management. Preoperative imaging allows for confirmation of the specific type of variation and facilitates the development of personalized implementation strategies. These strategies ensure both radical tumor eradication and effective preservation of liver function. This approach provides a new perspective for managing such rare vascular anomalies. Complete details are available in the published article.

INTRODUCTION

Hepatic arterial variations are critical anatomical considerations in surgical procedures. Preoperative vascular reconstruction to identify variant anatomy allows for personalized surgical planning, ensuring both oncological radicality and preservation of hepatic function. This article reports and analyzes a rare case of a complete replacement-type left hepatic artery (LHA) originating from the left gastric artery (LGA).

CASE PRESENTATION

Chief complaints

A 62-year-old male presented with a 6-month history of dysphagia after eating.

History of present illness

The patient initially ignored mild symptoms, but progressive worsening led to evaluation on March 3, 2025, at Linze County People’s Hospital. Esophagogastroduodenoscopy (EGD) revealed: (1) Cardia/gastric fundus carcinoma; and (2) Chronic atrophic gastritis. Biopsy confirmed gastric adenocarcinoma. No significant weight loss or other symptoms were reported.

History of past illness

No history of hepatitis, tuberculosis, hypertension, diabetes, coronary artery disease, or prior surgeries. No drug allergies or substance abuse.

Personal and family history

Resided locally with no exposure to endemic regions. No smoking or alcohol use.

Physical examination

Soft abdomen without distension, venous engorgement, or palpable masses. Mild epigastric tenderness without rebound. Normal bowel sounds; negative Murphy’s sign and shifting dullness.

Laboratory examinations

Liver function shows no abnormality.

Imaging examinations

EGD: Esophageal gastric mucosal heterotopia; cardia/fundal carcinoma; gastric angle ulcer; active C2 atrophic gastritis.

Pathology: Moderately differentiated adenocarcinoma (fundus); chronic gastritis with intestinal metaplasia (gastric angle).

Abdominal contrast-enhanced computed tomography (CT): Irregular thickening of the cardia/fundal wall with heterogeneously enhancing soft tissue. A 1.2 cm × 1.1 cm lymph node in the hepatogastric space. The LHA arose from the mid-segment of the LGA, coursing through the hepatogastric ligament into the left portal vein (Figures 1 and 2).

Figure 1 Coronal and cross-sectional computed tomography images of the abdomen. A: Cross-sectional computed tomography (CT) image of the abdomen; B: Coronal CT image of the abdomen. Both arrows indicate variant blood vessels.

Figure 2 Intraoperative hepatic left arterial vascular variant with no other surrounding hepatic artery branches. LGA: Left gastric artery; LHA: Left hepatic artery; CA: Celiac artery trunk; CHA: Common hepatic artery.

FINAL DIAGNOSIS

Gastric adenocarcinoma.

TREATMENT

Intraoperative dissection confirmed the LHA originating from the LGA (Figure 3). The LGA was ligated proximally, preserving the variant LHA. Postoperative recovery was uncomplicated.

Figure 3 Summary diagram of common vascular variations related to gastric cancer surgery. A: Normal type, the common hepatic artery originated from the celiac artery trunk, giving off the proper hepatic artery and the gastroduodenal artery, which continues to divide into the right gastric artery and the right and left hepatic arteries[11]; B: Variant origin of the left hepatic artery from the left gastric artery; C: Right hepatic artery originating from the superior mesenteric artery; D: Left hepatic artery variant originating from the left gastric artery and the right hepatic artery originating from the superior mesenteric artery[12,13]; E: Left parahepatic artery originating from the left gastric artery[12-17]; F: Right parahepatic artery originating from the superior mesenteric artery; G: Left parahepatic artery originating from the left gastric artery and right parahepatic artery originating from the superior mesenteric artery; H: Right hepatic artery originating from the superior mesenteric artery and left parahepatic artery originating from the left gastric artery; I: Common hepatic artery originating from the superior mesenteric artery; J: Common hepatic artery originating from the left gastric artery[12-15]; K: Left hepatic artery variant originating from the left gastric artery but no other hepatic arterial branches around. CHA: Common hepatic artery; CA: Celiac artery; PHA: Proper hepatic artery; GDA: Gastroduodenal artery; RGA: Right gastric artery; LHA: Left hepatic arteries; SA: Splenic artery.

OUTCOME AND FOLLOW-UP

No hepatic dysfunction or recurrence observed during 5-year follow-up.

DISCUSSION

The liver is a common anatomical site in intraoperative surgery, and knowledge of the hepatic artery system and its vascular variants in particular, is crucial to avoid intraoperative injuries. Although most of the vascular variations have been documented in the literature and book descriptions, extremely rare cases can mostly be encountered only in clinical practice. Therefore, surgeons should document these vascular variants and analyze them in conjunction with preoperative examinations when appropriate, when dealing with hepatic vasculature, which can provide more detailed preoperative planning for patients[1].

Knowledge of the distribution of the hepatic vascular system is essential for the surgeon and interventionalist, and its “standard” structure begins at the celiac trunk CT, which enters the splenic artery, the left gastric artery, and the common hepatic artery at the level of thoracic vertebrae 12. The common hepatic artery gives rise to three branches: The LHA, the proper hepatic artery, and the gastroduodenal artery. The proper hepatic artery bifurcates into the right and left hepatic arteries, which supply their respective lobes of the liver, whereas the right hepatic artery (RHA) supplies the gallbladder via the cystic artery[2]. The exact mechanism leading to the hepatic arterial vascular variant is currently unknown, with a high probability of originating from incomplete development of the ventral axis during embryonic development. The main cause is mostly considered to be incomplete development of the vasculature of the hepatic system and failure of vascular segregation, thus forcing the necessary circulation to come from non-normal origins[3,4]. Among the variants, the incidence of left hepatic artery originating from the LGA is 8%-12% (Michels type II), but complete substitution (no other hepatic artery branches) is rarer[5]. In contrast to the standard configuration of the hepatic circulation, most of the known variants of the hepatic vascular system to date have been categorized under Michels' classification system, which was established in 1955 and later expanded in 1966[5] (Table 1). Michels' original classification included 5 different types of variants, but subsequent studies have doubled it to at least 10 unique classifications[6] (Figure 3). Among these, the present patient belonged to Michels' classification type II and had no other hepatic artery branches, as shown in Figure 3K.

Table 1 The Michels’ class of the hepatic arterial anatomy.

Hepatic arterial anatomy	Michels’ class
Normal anatomy	Type I
LHA branching from LGA	Type II
RHA branching from SMA	Type III
LHA branching from LGA & RHA branching from SMA	Type IV
A LHA branching from LGA	Type V
A RHA branching from SMA	Type VI
A LHA branching from LGA and A RHA branching from SMA	Type VII
A LHA branching from LGA & RHA branching from SMA	Type VII
CHA branching from SMA	Type IX
CHA branching from LGA	Type X

CHA: Common hepatic artery; CA: Celiac artery; LHA: Left hepatic artery; LGA: Left gastric artery; RHA: Right hepatic artery; SMA: Spinal muscular atrophy.

A LHA originating from the LGA is a critical anatomical variant. CT imaging currently excels in vascular visualization[7], and is routinely used for preoperative assessment, enabling the accurate and clear visualization of the anatomy of both the LHA and the RHA. Hepatic arterial variations in the porta hepatis increase the risk of impaired hepatic arterial blood supply. This may lead to unexpected bleeding or ischemia, as well as a higher incidence of biliary anastomotic leak, transient liver functional abnormalities, and potentially even liver failure[8]. Preoperative simulation facilitates individualized surgical planning[9], thereby minimizing complications through: Proactively dissecting the identified variant branch prior to surgery. Avoiding inadvertent transection of the LHA during the resection of the LGA[10].

CONCLUSION

This case describes a relatively rare hepatic circulatory system variant, predominantly a complete replacement type of left hepatic artery variant originating from the left gastric artery, demonstrating the significance of diagnosing and managing this rare vascular variant. In this article, a thorough diagnostic evaluation, including imaging analysis and intraoperative exploration, enabled accurate identification of the variant vessel, leading to successful radical surgical treatment. In addition, routine preoperative angiography, such as enhanced CT and CT angiography or arterial digital subtraction angiography, can usually identify variant hepatic arteries and their types, guiding intraoperative dissection. From another perspective, we can also observe the relationship between the variant hepatic vessels and the tumor, such as tumor invasion of an ectopic hepatic artery may affect the radical tumor resection and relate to the surgical decision. The variant hepatic artery may pass through the pancreas or even the tumor and cause postoperative hepatic insufficiency or even failure, especially in patients with obstructive jaundice.

ACKNOWLEDGEMENTS

The authors sincerely thank the patient for providing informed consent to publish this case report and accompanying medical images in an anonymized manner.