Arterial supply and biliary drainage of the dorsal liver: a dissection study using controlled specimens

Radiation Segmentectomy for the Treatment of Primary Hepatic Malignancies of the Caudate Lobe: A Case Series

PURPOSE

Tumors involving the caudate lobe present a unique therapeutic challenge due to their complex anatomy and the safety and efficacy of locoregional therapy can be variable. The purpose of this study is to analyze the outcomes of radiation segmentectomy for primary caudate lobe tumors.

MATERIALS AND METHODS

Eight patients [5 women and 3 men; median age = 69 y (range 50-79)] that underwent transarterial radioembolization (TARE) using yttrium-90 (Y90) glass microspheres for primary caudate lobe tumors (hepatocellular carcinoma = 6, intrahepatic cholangiocarcinoma = 2) from August 2017 to March 2021 were retrospectively analyzed. Descriptive statistics, treatment parameters, tumor response (using modified response evaluation criteria in solid tumors), adverse events [using common terminology criteria for adverse events (CTCAE)], and survival outcomes were evaluated.

RESULTS

Eight primary caudate lobe tumors with a median size of 2.2 cm [interquartile range (IQR), 1.7-3.3] and Child-Pugh class A liver function underwent TARE of the caudate lobe. The median radiation dose was 596 Gy (IQR 356-1585), median total activity was 0.84 GBq (IQR 0.56-1.31), median specific activity was 473 Bq/sphere (IQR 226-671), and the median number of Y90 microspheres used was 1.4 million (IQR 1.2-3.4). All complications were CTCAE grade 1, and no clinically significant hilar plate complications were observed. In targeted tumors, complete response was seen in all patients.  At a median follow-up period of 16.6 months (IQR 6.6-21.6) 75% (6/8) of patients were alive with no in-field progression.

CONCLUSION

Radiation segmentectomy of primary caudate lobe tumors appears effective and is well tolerated in this limited case series within the described treatment parameters.

LEVEL OF EVIDENCE

Level 4, Case Series.

Surgical anatomy of caudate bile ducts: Silicon-injected cadaveric-livers dissected under magnification

Backgrounds/Aims

Caudate bile ducts are routinely presented using negative images as X-ray-cholangiograms. Such information does not provide for instant surgical orientation of the relationships between caudate ducts and the liver itself−a paramount skill for successfully performing hilar cholangiocarcinoma resection and living donor/split transplantation. This study presents a 4-step procedure to prepare, dissect and present, high-quality, 2D/3D anatomical images of biliary caudate ducts in a surgically meaningful way.

Methods

Fresh cadavers had arteries and veins injected with colored-silicone and ducts bile-stained to facilitate recognition. Dissections were performed under magnification with microsurgical instruments. Stepwise 2D and 3D images were acquired.

Results

Dissection of silicone-injected specimens under magnification allows identification of caudate structures, its portions and processes while preserving tridimensional arrangement of caudate vessels, biliary ducts and collectors. Such dissections can help enhance cholangiogram interpretation and favor its direct correlation to intraoperative findings.

Conclusions

A procedure including: a) preparation of high-quality cadaveric livers, b) with silicone-injected vessels, c) dissected under surgical microscope and d) documented using 2&3D images aimed at enhancing the clinical understanding of the anatomy of caudate ducts is presented. It has potential to enhance morphological and clinical understanding of caudate ducts, being useful to anatomists and surgeons alike.

Analysis of the caudate artery with three-dimensional imaging

BACKGROUND/PURPOSE

To date there have been only a few radiological studies of the caudate artery. This study aimed to precisely analyze the caudate artery as well as the relationship between the caudate arteries, the arterial plexus at the hilar plate, and the hilar bile duct.

METHODS

Reconstructed three-dimensional (3D) computed tomography images from 50 patients during hepatic arteriography were analyzed. The caudate arteries were classified as right branches (Irs) or left branches (Ils). The communicating artery (CA) was defined as the artery connecting the right, left, segmental, and common hepatic arteries.

RESULTS

The caudate artery was divided into 3 types: an independent branch (Type 1); the common tract formed by Ir and Il (Type 2); and an arterial branch from the CA (Type 3). The CA was recognized in 25 of 50 patients. There was a total of 65 arteries to the hilar bile duct observed in 40 patients, and 24 (37 %) of these 65 arteries to the hilar bile duct originated from the caudate artery or CA.

CONCLUSION

The caudate artery plays an important role not only in connecting the blood supply of the right and left livers but in the blood supply to the hilar bile duct.

CT and MR cholangiography: advantages and pitfalls in perioperative evaluation of biliary tree

Recent developments in imaging technology have enabled CT and MR cholangiopancreatography (MRCP) to provide minimally invasive alternatives to endoscopic retrograde cholangiopancreatography for the pre- and post-operative assessment of biliary disease. This article describes anatomical variants of the biliary tree with surgical significance, followed by comparison of CT and MR cholangiographies. Drip infusion cholangiography with CT (DIC-CT) enables high-resolution three-dimensional anatomical representation of very small bile ducts (e.g. aberrant branches, the caudate branch and the cystic duct), which are potential causes of surgical complications. The disadvantages of DIC-CT include the possibility of adverse reactions to biliary contrast media and insufficient depiction of bile ducts caused by liver dysfunction or obstructive jaundice. Conventional MRCP is a standard, non-invasive method for evaluating the biliary tree. MRCP provides useful information, especially regarding the extrahepatic bile ducts and dilated intrahepatic bile ducts. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRCP may facilitate the evaluation of biliary structure and excretory function. Understanding the characteristics of each type of cholangiography is important to ensure sufficient perioperative evaluation of the biliary system.