Anatomic Variations of the Hepatic Artery in 5625 Patients

A rare case of replaced right hepatic artery with direct aortic origin described angiographically during trans-arterial radioembolization

Normal hepatic arterial anatomy consists of the right hepatic artery and left hepatic artery branching from the common hepatic artery. Despite this being the most common configuration, many variations have been described. Here, we present a rare variant of hepatic arterial anatomy- a replaced right hepatic artery with direct aortic origin. Additionally, the patient was found to have a dorsal pancreatic artery originating from the replaced right hepatic artery This was angiographically identified during mapping for transarterial radioembolization for hepatocellular carcinoma. The unique anatomy in this case and the effect it had on transarterial radioembolization planning described herein demonstrates the necessity of understanding variant hepatic arterial anatomy in endovascular hepatic interventions.

Unique Hepatic Arterial Pattern Associated With the Presence of Accessory Proper Hepatic Artery and Middle Hepatic Artery

Vascular variations of the coeliac trunk are relatively common, with documented occurrences including trifurcation of the common hepatic artery (CHA) and the presence of accessory and replaced hepatic arteries. This case report describes a novel variation wherein the CHA trifurcates into the proper hepatic artery (PHA), gastroduodenal artery, and accessory PHA (APHA). This particular trifurcation pattern has not been previously recorded. The APHA further branches into two arteries that supply the right lobe of the liver. Additionally, a middle hepatic artery (MHA), originating from the PHA, was identified alongside the right and left hepatic arteries. The MHA serves as a hilar artery that drains segment IV of the liver. This anatomical variant does not conform to any existing coeliac trunk classifications. Understanding this unique arterial pattern is crucial for liver transplantation, as well as procedures involving the pancreas, duodenum, and gallbladder, and for interventional techniques such as transcatheter arterial chemoembolization and transarterial radionuclide therapy.

Early bifurcation of the common hepatic artery: A pitfall that should be known and recognized

Early bifurcation of the common hepatic artery (EBCHA) is a rare anatomical variation (1%), that is often overlooked but can lead to accidental ligation of the right branch of the hepatic artery with consequent arterial ischemia of the right liver and potentially very serious complications during pancreaticoduodenectomy, partial hepatectomy, or liver harvesting for transplantation. It may be difficult to diagnose EBCHA using transverse imaging sections. However, on standard CT sections with intravenous contrast injection, three warning signs should allow the image reader to suspect it: presence of two hepatic arteries to the right of the celiac trunk, presence of a retro-portal hepatic artery, and absence of a right hepatic artery arising from the superior mesenteric artery. Analysis of the CT with reconstruction then allows for definitive diagnosis and limits the risk of accidental arterial injury or ligation.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Surgical techniques for robotic right donor hepatectomy, part 1: robotic hilar dissection and right lobe mobilization

Robotic surgery is emerging as a feasible minimally invasive approach for donor hepatectomy at specialized centers. The aim of this article is to systematically describe the surgical techniques for robotic hilar dissection and right lobe mobilization in right donor hepatectomy. The setup of the robotic arms, the dissection of inflow vessels and retrohepatic inferior vena cava, and the pearls and pitfalls of these two parts of the operation are detailed.

Intrahepatic and anterior course of the inferior vena cava: CT image and 3D reconstruction of a rare anatomical variation

The widespread use of computed tomography (CT) for diagnosing and screening abdominal conditions often reveals rare, asymptomatic anomalies. There is a wide range of documented congenital variations in the anatomy of the inferior vena cava (IVC) and hepatic veins. In this report, we detail an exceptionally unusual variant of the IVC that follows a frontward and intraliver course, terminating at the anterior section of the right atrium. To gain a deeper insight into this anomaly, we employed 3D reconstruction techniques using the software Slicer and Blender.

Novel embryological classifications of hepatic arteries based on the relationship between aberrant right hepatic arteries and the middle hepatic artery: A retrospective study of contrast-enhanced computed tomography images

BACKGROUND

Variations in hepatic arteries are frequently encountered during pancreatoduodenecomy. Identifying anomalies, especially the problematic aberrant right hepatic artery (aRHA), is crucial to preventing vascular-related complications. In cases where the middle hepatic artery (MHA) branches from aRHAs, their injury may lead to severe liver ischemia. Nevertheless, there has been little information on whether MHA branches from aRHAs. This study aimed to investigate the relationship between aRHAs and the MHA based on the embryological development of visceral arteries.

METHODS

This retrospective study analyzed contrast-enhanced computed tomography images of 759 patients who underwent hepatobiliary-pancreatic surgery between January 2011 and August 2022. The origin of RHAs and MHA courses were determined using three-dimensional reconstruction. All cases of aRHAs were categorized into those with or without replacement of the left hepatic artery (LHA).

RESULTS

Among the 759 patients, 163 (21.4%) had aRHAs. Five aRHAs patterns were identified: (Type 1) RHA from the gastroduodenal artery (2.7%), (Type 2) RHA from the superior mesenteric artery (SMA) (12.7%), (Type 3) RHA from the celiac axis (2.1%), (Type 4) common hepatic artery (CHA) from the SMA (3.5%), and (Type 5) separate branching of RHA and LHA from the CHA (0.26%). The MHA did not originate from aRHAs in Types 1-3, whereas in Type 4, it branched from either the RHA or LHA.

CONCLUSIONS

Based on the developmental process of hepatic and visceral arteries, branching of the MHA from aRHAs is considered rare. However, preoperative recognition and intraoperative anatomical assessment of aRHAs is essential to avoid injury.

Transarterial chemoembolization in a patient with the replaced right hepatic and left gastric arteries arising from the abdominal aorta: a new anatomical variation

PURPOSE

Knowing the anatomical variation of the coeliac trunk (CT) and its detailed interpretation in the preoperative period is important for the prevention of iatrogenic injury during liver surgery or endovascular intervention on the coeliac trunk and its branches.

METHODS

A diagnostic abdominal computed tomography angiography (CTA) was performed in a 61-year-old male patient, who was investigated for a liver cancer and chemoembolization was planned.

RESULTS

CTA reveals that right hepatic artery (RHA) arises directly from the abdominal aorta, at the level of CT. This vessel coursing to the right hepatic lobe, functioning therefore as a replaced right hepatic artery (RRHA). Also, the left gastric artery (LGA) arises directly from the abdominal aorta. This patient successfully underwent chemoembolization from RRHA.

CONCLUSION

We presented a case of new anatomical variation involving the origination of RRHA and LGA from the abdominal aorta.

Recent advances in computerized imaging and its vital roles in liver disease diagnosis, preoperative planning, and interventional liver surgery: A review

The earliest and most accurate detection of the pathological manifestations of hepatic diseases ensures effective treatments and thus positive prognostic outcomes. In clinical settings, screening and determining the extent of a pathology are prominent factors in preparing remedial agents and administering appropriate therapeutic procedures. Moreover, in a patient undergoing liver resection, a realistic preoperative simulation of the subject-specific anatomy and physiology also plays a vital part in conducting initial assessments, making surgical decisions during the procedure, and anticipating postoperative results. Conventionally, various medical imaging modalities, e.g., computed tomography, magnetic resonance imaging, and positron emission tomography, have been employed to assist in these tasks. In fact, several standardized procedures, such as lesion detection and liver segmentation, are also incorporated into prominent commercial software packages. Thus far, most integrated software as a medical device typically involves tedious interactions from the physician, such as manual delineation and empirical adjustments, as per a given patient. With the rapid progress in digital health approaches, especially medical image analysis, a wide range of computer algorithms have been proposed to facilitate those procedures. They include pattern recognition of a liver, its periphery, and lesion, as well as pre- and postoperative simulations. Prior to clinical adoption, however, software must conform to regulatory requirements set by the governing agency, for instance, valid clinical association and analytical and clinical validation. Therefore, this paper provides a detailed account and discussion of the state-of-the-art methods for liver image analyses, visualization, and simulation in the literature. Emphasis is placed upon their concepts, algorithmic classifications, merits, limitations, clinical considerations, and future research trends.

Modified Appleby procedure for locally advanced pancreatic carcinoma: A primer for the radiologist

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent pancreatic neoplasm accounting for more than 90% of pancreatic malignancies. Surgical resection with adequate lymphadenectomy remains the only available curative strategy for patients with PDAC. Despite improvements in both chemotherapy regimen and surgical care, body/neck PDAC still conveys a poor prognosis because of the vicinity of major vascular structures, including celiac trunk, which favors insidious disease spread at the time of diagnosis. Body/neck PDAC involving the celiac trunk is considered locally advanced PDAC in most guidelines and therefore not eligible for upfront resection. However, a more aggressive surgical approach (i.e., distal pancreatectomy with splenectomy and en-bloc celiac trunk resection [DP-CAR]) was recently proposed to offer hope for cure in selected patients with locally advanced body/neck PDAC responsive to induction therapy at the cost of higher morbidity. The so-called "modified Appleby procedure" is highly demanding and requires optimal preoperative staging as well as appropriate patient preparation for surgery (i.e., preoperative arterial embolization). Herein, we review current evidence regarding DP-CAR indications and outcomes as well as the critical role of diagnostic and interventional radiology in patient preparation before DP-CAR, and early identification and management of DP-CAR complications.

Transarterial chemoembolization for hepatocellular carcinoma: 2023 expert consensus-based practical recommendations of the Korean Liver Cancer Association

Transarterial chemoembolization (TACE) was introduced in 1977 with the administration of chemotherapeutic agent to gelatin sponge particles through the hepatic artery in patients with hepatocellular carcinoma (HCC) and was established as conventional TACE using Lipiodol in the 1980s. In the 2000s, drug-eluting beads were developed and applied clinically. Currently, TACE is a commonly used non-surgical treatment modality for patients with HCC who are unsuitable for curative treatment. Considering the vital role of TACE in the management of HCC, it is crucial to organize current knowledge and expert opinions regarding patient preparation, procedural techniques, and post-treatment care in TACE, which can enhance therapeutic efficacy and safety. A group of 12 experts in the fields of interventional radiology and hepatology, convened by the Research Committee of the Korean Liver Cancer Association (KLCA), has developed expert consensus-based practical recommendations in TACE. These recommendations have been endorsed by the Korean Society of Interventional Radiology and provide useful information and direction in performing TACE procedure as well as pre- and post- procedural patient care.

Donor hepatic artery reconstruction based on human embryology: A case report

BACKGROUND

Embryonic hepatic artery anatomy simplifies its identification during liver transplantation. Injuries to the donor hepatic artery can cause complications in this process. The hepatic artery's complex anatomy in adults makes this step challenging; however, during embryonic development, the artery and its branches have a simpler relationship. By restoring the embryonic hepatic artery anatomy, surgeons can reduce the risk of damage and increase the procedure's success rate. This approach can lead to improved patient outcomes and lower complication rates.

CASE SUMMARY

In this study, we report a case of donor liver preparation using a donor hepatic artery preparation based on human embryology. During the preparation of the hepatic artery, we restored the anatomy of the celiac trunk, superior mesenteric artery, and their branches to the state of the embryo at 5 wk. This allowed us to dissect the variant hepatic artery from the superior mesenteric artery and left gastric artery during the operation. After implanting the donor liver into the recipient, we observed normal blood flow in the donor hepatic artery, main hepatic artery, and variant hepatic artery, without any leakage.

CONCLUSION

Donor hepatic artery preparation based on human embryology can help reduce the incidence of donor hepatic artery injuries during liver transplantation.

Transarterial chemoembolization for hepatocellular carcinoma: 2023 Expert consensus-based practical recommendations of the Korean Liver Cancer Association

Transarterial chemoembolization (TACE) was introduced in 1977 with the administration of chemotherapeutic agent to gelatin sponge particles through the hepatic artery in patients with hepatocellular carcinoma (HCC) and was established as conventional TACE using Lipiodol in the 1980s. In the 2000s, drug-eluting beads were developed and applied clinically. Currently, TACE is a commonly used non-surgical treatment modality for patients with HCC who are unsuitable for curative treatment. Considering the vital role of TACE in the management of HCC, it is crucial to organize current knowledge and expert opinions regarding patient preparation, procedural techniques, and post-treatment care in TACE, which can enhance therapeutic efficacy and safety. A group of 12 experts in the fields of interventional radiology and hepatology, convened by the Research Committee of the Korean Liver Cancer Association (KLCA), has developed expert consensus-based practical recommendations in TACE. These recommendations have been endorsed by the Korean Society of Interventional Radiology and provide useful information and direction in performing TACE procedure as well as pre- and post- procedural patient care.

Transarterial Chemoembolization for Hepatocellular Carcinoma: 2023 Expert Consensus-Based Practical Recommendations of the Korean Liver Cancer Association

Transarterial chemoembolization (TACE) was introduced in 1977 with the administration of chemotherapeutic agent to gelatin sponge particles through the hepatic artery in patients with hepatocellular carcinoma (HCC) and was established as conventional TACE using Lipiodol in the 1980s. In the 2000s, drug-eluting beads were developed and applied clinically. Currently, TACE is a commonly used non-surgical treatment modality for patients with HCC who are unsuitable for curative treatment. Considering the vital role of TACE in the management of HCC, it is crucial to organize current knowledge and expert opinions regarding patient preparation, procedural techniques, and post-treatment care in TACE, which can enhance therapeutic efficacy and safety. A group of 12 experts in the fields of interventional radiology and hepatology, convened by the Research Committee of the Korean Liver Cancer Association (KLCA), has developed expert consensus-based practical recommendations in TACE. These recommendations have been endorsed by the Korean Society of Interventional Radiology and provide useful information and direction in performing TACE procedure as well as pre- and post-procedural patient care.

A deviant anterior portal vein in the hepatoduodenal ligament with aberrant origin of hepatic arteries directly from the celiac trunk: A case report of two patients underwent pylorus preserving pancreatoduodenectomy (PPPD)

INTRODUCTION

The portal vein (PV) originates behind the neck of the pancreas, where it is formed classically by the union of the superior mesenteric vein (SMV) and the splenic vein (SV) [1]. It courses upwards towards the liver in the free margin of the lesser omentum, the hepatoduodenal ligament, along with other structures of the portal triad, i.e. proper hepatic artery (PHA) and common bile duct (CBD) anterior to it [1]. The PV is found posterior to the PHA and CBD. The abdominal aorta perfuses abdominal viscera via three ventral branches celiac trunk (CA), superior mesenteric artery (SMA), and inferior mesenteric artery (IMA). The celiac trunk supplies the derivates of the foregut and is divided into the left gastric artery (LGA), splenic artery (SA), and common hepatic artery (CHA). The CHA, after its origin, is divided into the gastroduodenal artery (GDA) and PHA. After giving off the right gastric artery (RGA), the PHA bifurcates into the right and left hepatic arteries (RHA, LHA) [2].

IMPORTANCE

This case report aims to share the rare variations in the anatomy of hepatoduodenal ligament structures to increase awareness and understanding among fellow surgeons which may reduce complications.

CASE PRESENTATION

We are reporting 2 cases in which during pancreaticoduodenectomy Portal vein was present anteriorly in the portal triad and the common hepatic artery was absent; instead, both the right and left hepatic arteries originated directly from the CA posterior to PV. This retro-portal origin of hepatic arteries directly from CA is not reported in Michel's classification of hepatic artery variations [3].

CLINICAL DISCUSSION

The confluence of SMV and SV posterior to the neck of the pancreas forms the PV. The portal vein runs upwards in the free edge of the lesser omentum. Anteriorly it is related to the CBD laterally and CHA anteromedially. Posteriorly it is related to the inferior vena cava (IVC), and PV is separated from IVC by epiploic foramen [4]. The overall reported incidence in the variation of the portal vein anatomy is 25%. Among all the variations seen, the anterior PV with posteriorly bifurcating hepatic artery is present in only 10 % of the cases [5]. There is an increased risk of hepatic artery anatomical variation in the presence of portal vein variants. Michel's classification [6] classified variations in the hepatic artery anatomy. In our cases, the hepatic artery anatomy was standard and was classified as Type 1. The bile duct was normal anatomic (lateral to the PV). Hence our cases are unique in describing isolated variant locations and courses. Detailed information about the anatomy of the portal triad and all possible variants can help reduce the incidence of iatrogenic complications during surgeries like liver transplants and pancreatoduodenectomies. Before the advancement of modern imaging techniques, the variations in the anatomy of the portal triad were clinically irrelevant and considered less significant. However, recent literature supports that variant anatomy of the hepatic portal triad can prolong the time of surgery and increase the risk of iatrogenic complications. The clinical relevance of variable hepatic artery anatomy has immense importance in hepatobiliary surgeries, including liver transplants where the viability of the graft depends on adequate arterial perfusion. In addition to that, in pancreatoduodenectomies, aberrant arterial anatomy with a reteroportal course is associated with an increased number of reconstructions [7] and bilio-enteric anastomosis disruptions since the CBD derives its blood supply from the hepatic arteries. Therefore, the imaging must be carefully interpreted with radiologists' help before surgical planning. As surgeons preoperative imaging is usually seen for the abnormal origin of hepatic arteries and vascular involvement in case of malignancies. "Eyes don't see what mind doesn't know", the anterior portal vein is a rare entity and should be considered while reviewing preoperative imaging for operative planning. In our cases, EUS and CT scans, both were done but we determined resectability on scans and abnormal origin (replaced or accessory arteries) only. Above mentioned findings were noted during surgery but now in every preoperative scan, we try to determine the presence of all possible variations including the reported ones.

CONCLUSION

Detailed knowledge about the anatomy of the portal triad and all possible variants can help reduce the incidence of iatrogenic complications during surgeries like liver transplants and pancreatoduodenectomies. It also reduces the time of surgery. A careful review of all possible variations in preoperative scans with appropriate knowledge all anatomical variations helps avoid unpleasant events and hence, reduce morbidity and mortality.

Importance of Anatomical Variation of the Hepatic Artery for Complicated Liver and Pancreatic Surgeries: A Review Emphasizing Origin and Branching

Knowledge of anatomical variations of the hepatic artery from its origin to intrahepatic segmentation is of utmost importance for planning upper abdominal surgeries including liver transplantation, pancreatoduodenectomy, and biliary reconstruction. The origin and branching pattern of the hepatic artery was thoroughly described by the classification of Michels and Hiatt. Some rare variations of the hepatic artery were classified by Kobayashi and Koops. By the use of the multidetector computed tomography (MDCT) technique, the branching pattern of the hepatic artery can be visualized quite accurately. Unawareness of these arterial variations may lead to intraoperative injuries such as necrosis, abscess, and failure of the liver and pancreas. The origin and course of the aberrant hepatic arteries are crucial in the surgical planning of carcinoma of the head of the pancreas and hepatobiliary surgeries. In liver transplant surgeries, to minimize intraoperative bleeding complications and postoperative thrombosis, exact anatomy of the branching of the hepatic artery, its variations and intrahepatic course is of utmost importance. This review discusses variations in the anatomy of the hepatic artery from its origin to branching by the use of advanced imaging techniques and its effect on the liver, pancreatic, biliary and gastric surgeries.

Lesion or Pseudolesion? A Comprehensive Description of Perfusion-Based Liver Alterations on Contrast-Enhanced Computed Tomography and Literature Review

ABSTRACT

Pseudolesions on contrast-enhanced computed tomography represent a diagnostic challenge for radiologists because they could be difficult to distinguish from true space-occupying lesions. This article aims to provide a detailed overview of these entities based on radiological criteria (hyperattenuation or hypoattenuation, localization, morphology), as well as a brief review of the hepatic vascular anatomy and pathophysiological process. Relevant examples from hospital case series are reported as helpful hints to assist radiologists in recognizing and correctly diagnosing these abnormalities.

Factors impacting survival after transarterial radioembolization in patients with hepatocellular carcinoma: Results from the prospective CIRT study

Background & Aims

Transarterial radioembolization (TARE) with Yttrium-90 resin microspheres is an established treatment option for patients with hepatocellular carcinoma (HCC). However, optimising treatment application and patient selection remains challenging. We report here on the effectiveness, safety and prognostic factors, including dosing methods, associated with TARE for HCC in the prospective observational CIRT study.

Methods

We analysed 422 patients with HCC enrolled between Jan 2015 and Dec 2017, with follow-up visits every 3 months for up to 24 months after first TARE. Patient characteristics and treatment-related data were collected at baseline; adverse events and time-to-event data (overall survival [OS], progression-free survival [PFS] and hepatic PFS) were collected at every 3-month follow-up visit. We used the multivariable Cox proportional hazard model and propensity score matching to identify independent prognostic factors for effectiveness outcomes.

Results

The median OS was 16.5 months, the median PFS was 6.1 months, and the median hepatic PFS was 6.7 months. Partition model dosimetry resulted in improved OS compared to body surface area calculations on multivariable analysis (hazard ratio 0.65; 95% CI 0.46-0.92; p = 0.0144), which was confirmed in the exact matching propensity score analysis (hazard ratio 0.56; 95% CI 0.35-0.89; p = 0.0136). Other independent prognostic factors for OS were ECOG-performance status >0 (p = 0.0018), presence of ascites (p = 0.0152), right-sided tumours (p = 0.0002), the presence of portal vein thrombosis (p = 0.0378) and main portal vein thrombosis (p = 0.0028), ALBI grade 2 (p = 0.0043) and 3 (p = 0.0014). Adverse events were recorded in 36.7% of patients, with 9.7% of patients experiencing grade 3 or higher adverse events.

Conclusions

This large prospective observational dataset shows that TARE is an effective and safe treatment in patients with HCC. Using partition model dosimetry was associated with a significant improvement in survival outcomes.

Impact and implications

Transarterial radioembolization (TARE) is a form of localised radiation therapy and is a potential treatment option for primary liver cancer. We observed how TARE was used in real-life clinical practice in various European countries and if any factors predict how well the treatment performs. We found that when a more complex but personalised method to calculate the applied radiation activity was used, the patient responded better than when a more generic method was used. Furthermore, we identified that general patient health, ascites and liver function can predict outcomes after TARE.

Clinical trial number

NCT02305459.