Association between anatomic variations of extrahepatic and intrahepatic bile ducts: Do look up!

Biliary anatomic variations are usually asymptomatic, but they may cause problems in diagnostic investigations and interventional and surgical procedures, increasing both their technical difficulty and their postoperative complication rates. The aim of the present study was to evaluate the prevalence of anatomic variations in the intrahepatic biliary ducts (IHBD) in relation to demographical and clinical characteristics in a large study population requiring magnetic resonance cholangiopancreatography (MRCP) for various clinical conditions. The possible association between IHBD and extrahepatic biliary ducts (EHBD) variants was then explored. From January 2017 to May 2019, 1004 patients underwent MRCP. Demographical and clinical data were collected. IHBD and EHBD anatomy were recorded and the EHBD anatomy was classified using both qualitative and quantitative classifications. The presence of a type 3 EHBD variant (an abnormal proximal cystic duct [CD] insertion) in both qualitative and quantitative classifications and an intrapancreatic CD were associated with the presence of IHBD variants at univariate analysis (p = 0.008, p = 0.019, and p = 0.001, respectively). The presence of a posterior or medial insertion of the CD into the EHBD was a strong predictive factor of the presence of IHBD variants both at uni- and multivariate analysis (p = 0.002 and p = 0.003 for posterior insertion and p = 0.002 and p = 0.002 for medial insertion, respectively). The presence of gallstones on MRCP resulted in a strong predictor of the presence of an anatomical variant of the IHBD both at uni- and multivariate analysis (p = 0.027 and p = 0.046, respectively). In conclusion, the presence of a type 3 variant of the EHBD, an intrapancreatic CD and, especially, a posterior/medial CD insertion into the EHBD represent predictive factors of the concomitant presence of IHBD variants, thus radiologists must be vigilant when encountering these EHBD configurations and always remember to "look up" at the IHBD. Finally, the presence of an IHBD variant is a strong predictive factor of gallstones.

Oncogenic KRAS-expressing organoids with biliary epithelial stem cell properties give rise to biliary tract cancer in mice.

Biliary tract cancer (BTC) arises from biliary epithelial cells (BECs) and includes intrahepatic cholangiocarcinoma (IHCC), gallbladder cancer (GC), and extrahepatic cholangiocarcinoma (EHCC). Although frequent KRAS mutations and epigenetic changes at the INK4A/ARF locus have been identified, the molecular pathogenesis of BTC is unclear and the development of corresponding anticancer agents remains inadequate. We isolated epithelial cell adhesion molecule (EpCAM)-positive BECs from the mouse intrahepatic bile duct, gallbladder, and extrahepatic bile duct, and established organoids derived from these cells. Introduction of activated KRAS and homozygous deletion of Ink4a/Arf in the cells of each organoid type conferred the ability to form lethal metastatic adenocarcinoma with differentiated components and a pronounced desmoplastic reaction on cell transplantation into syngeneic mice, indicating that the manipulated cells correspond to BTC-initiating cells. The syngeneic mouse models recapitulate the pathological features of human IHCC, GC, and EHCC, and they should therefore prove useful for the investigation of BTC carcinogenesis and the development of new therapeutic strategies. Tumor cells isolated from primary tumors formed organoids in three-dimensional culture, and serial syngeneic transplantation of these cells revealed that their cancer stem cell properties were supported by organoid culture, but not by adherent culture. Adherent culture thus attenuated tumorigenic activity as well as the expression of both epithelial and stem cell markers, whereas the expression of epithelial-mesenchymal transition (EMT)-related transcription factor genes and mesenchymal cell markers was induced. Our data show that organoid culture is important for maintenance of epithelial cell characteristics, stemness, and tumorigenic activity of BTC-initiating cells.

Anatomy and development of the extrahepatic biliary system in mouse and rat: a perspective on the evolutionary loss of the gallbladder.

The gallbladder is the hepatobiliary organ for storing and secreting bile fluid, and is a synapomorphy of extant vertebrates. However, this organ has been frequently lost in several lineages of birds and mammals, including rodents. Although it is known as the traditional problem, the differences in development between animals with and without gallbladders are not well understood. To address this research gap, we compared the anatomy and development of the hepatobiliary systems in mice (gallbladder is present) and rats (gallbladder is absent). Anatomically, almost all parts of the hepatobiliary system of rats are topographically the same as those of mice, but rats have lost the gallbladder and cystic duct completely. During morphogenesis, the gallbladder-cystic duct domain (Gb-Cd domain) and its primordium, the biliary bud, do not develop in the rat. In the early stages, SOX17, a master regulator of gallbladder formation, is positive in the murine biliary bud epithelium, as seen in other vertebrates with a gallbladder, but there is no SOX17-positive domain in the rat hepatobiliary primordia. These findings suggest that the evolutionary loss of the Gb-Cd domain should be translated simply as the absence of a biliary bud at an early stage, which may correlate with alterations in regulatory genes, such as Sox17, in the rat. A SOX17-positive biliary bud is clearly definable as a developmental module that may be involved in the frequent loss of gallbladder in mammals.

One duct, two orifices, no names! the anatomy of the biliary cystic duct.

The biliary cystic duct (CD) connects the gallbladder to the extra-hepatic bile duct, and the point at which it does this delineates the division between the common hepatic duct and the common bile duct. Its clinical relevance in disease, and importance during interventions relating to the gallbladder mean that its normal and variant anatomy has been described extensively in literature. However, an aspect not yet fully described includes naming of its two orifices on either end. This is highly relevant for surgical, endoscopic, and percutaneous procedures. We describe these as encountered in normal CD and biliary tree anatomy. We believe this is crucial for interventions relating to the gallbladder and the biliary tree, including prevention of iatrogenic injury. Clin. Anat. 31:422-423, 2018. © 2018 Wiley Periodicals, Inc.

Normograms for the Extrahepatic Bile Duct Diameter in Children.

OBJECTIVE: The normal diameter of the extrahepatic bile duct (EHD) in children has been poorly studied. Prior studies have enrolled small subject numbers, have studied only specific pediatric age groups, or have potential bias due to loosely defined exclusion criteria. We sought to establish parameters for the normal diameter of the EHD in children from birth to late adolescence, including premature infants. METHODS: A 12½-month institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, retrospective chart review of all transabdominal ultrasounds performed on children (younger than 18 years) was conducted at a single pediatric tertiary referral center. Exclusion criteria included a past medical history of any pancreaticobiliary or hepatology disorder. New abnormal findings related to the liver, biliary system, or pancreas were also excluded. Recorded EHD measurements from review of the radiology reports were compiled. Estimated mean and 95% prediction intervals of EHD were calculated and reported for 6 nonoverlapping pediatric age groups. RESULTS: A total of 1016 ultrasounds on unique patients were included within the study. Estimated mean values and calculated 95% prediction intervals (in parentheses) for the diameter of the EHD were prematurity, 0.7 (0.3-1.7) mm; 0 to 2 months, 1.0 (0.4-2.3) mm; 3 to 11 months, 1.2 (0.5-2.9) mm; 1 to 4 years, 1.4 (0.6-3.3) mm; 5 to 12 years, 1.9 (0.8-4.3) mm; 13 to 17 years, 2.3 (1.0-5.2) mm. CONCLUSIONS: Our derived data of normal predicted parameters of the EHD diameter in children of all age groups will help guide clinicians in identifying those patients outside the norm that may benefit from additional testing.

Ancient Greek Terminology in Hepatopancreatobiliary Anatomy and Surgery.

Most of the terminology in medicine originates from Greek or Latin, revealing the impact of the ancient Greeks on modern medicine. However, the literature on the etymology of Greek words used routinely in medical practice is sparse. We provide a short guide to the etymology and meaning of Greek words currently used in the field of hepatopancreatobiliary (HPB) anatomy and surgery. Focusing on HPB medical literature, the etymology and origin of Greek words including suffixes and prefixes are shown and analyzed. For example, anatomy (anatomia) is a Greek word derived from the prefix ana- (on, upon) and the suffix -tomy from the verb temno meaning to cut. Surgery, however, is not a Greek word. The corresponding Greek word is chirourgiki derived from cheir (hand) and ergon (action, work) meaning the action made by hands. Understanding the root of Greek terminology leads to an accurate, precise and comprehensive scientific medical language, reflecting the need for a universal medical language as a standardized means of communication within the health care sector.

Anatomy and surgical relevance of Rouviere's sulcus.

Rouviere's sulcus (RS) (i.e., incisura hepatis dextra, Gans incisura) represents an important anatomical landmark. The aim of the study was to determine the frequency of the RS, its description, its location, its relations to the right portal pedicle and to the plane of the common bile duct, and the evaluation of the surgical relevance of the obtained data. Forty macroscopically healthy and undamaged livers were removed during autopsies from cadavers of both sexes. The RS was present in 82% of the cases and in these the open RS was identified in 70% of the livers. The fused type was observed in 12% of the cases; 18% of the livers had no sulcus. The mean length of the open type RS was 28 ± 2 mm (range 24-32 mm) and its mean depth was 6 ± 2 mm (range 4-8 mm). The right posterior sectional pedicle was found in the RS in 70% of the cases. In 5% of the livers, we also dissected a branch of the anterior sectional pedicle. Inside 25% of the RS, we found the vein of segment 6. The RS identification may avoid bile duct injury during laparoscopic cholecystectomy and enables elective vascular control during the right liver resection.

Fluorescence-guided laparoscopic cholecystectomy: a new technique for visualization of biliary system by using fluorescein.

BACKGROUND: Safe cholecystectomy requires confident identification of extrahepatic biliary anatomy. This is the first report of the use of fluorescein and ultraviolet light to improve visualization of biliary topography during laparoscopic cholecystectomy. METHODS: Five patients who had symptomatic gallstones underwent laparoscopic cholecystectomy with intraoperative intravenous fluorescein injection. Ultraviolet A from an LED light source was used to induce fluorescence of bile. It was delivered by a device that was designed and built by the authors. RESULTS: Within 4 to 5 minutes the bile ducts were shining with green fluorescence and were easily differentiated from the surrounding tissues. In all cases, identification of the extrahepatic biliary anatomy by the fluorescence technique preceded its identification with conventional white light. Fluorescence remained for the whole duration of operation that extended for 42 to 77 minutes. CONCLUSIONS: At laparoscopic cholecystectomy, intravenous fluorescein injection and ultraviolet A excitation induce bile ducts to fluoresce. The technique allows better and earlier real-time visualization of biliary anatomy than conventional white light. The technique is simple and inexpensive. It serves as an additional tool that would improve safety of laparoscopic cholecystectomy.

Variations in extra-hepatic biliary tree morphology and morphometry: a narrative review of literature with focus on cystohepatic triangle.

The morphometry and morphology of the components of extrahepatic biliary tree show extensive variations. A beforehand recognition of these variations is very crucial to prevent unintended complications while performing surgeries in this region. This study was conducted to analyse the configuration of the extrahepatic biliary tree and its possible variations, as well as measure the components that limit the cystohepatic triangle. Articles were searched in major online indexed databases (Medline and PubMed, Scopus, Embase, CINAHL Plus, Web of Science and Google Scholar) using relevant key words. A total of 73 articles matched the search criteria of which 55 articles were identified for data extraction. The length of left and right hepatic duct in majority of studies was found to be > 10 mm. A wide range of diameters of hepatic ducts were observed between 5 and 43 mm. The average length of cystic duct is around 20 mm. The length and diameter of the common bile duct are 50-150 mm and 3-9 mm, respectively. The most frequently observed pattern of insertion of cystic duct into common hepatic duct is right lateral, rarely anterior, or posterior spiral insertion can present. The results of this study will provide a standard reference range which instead will help to differentiate the normal and pathological conditions.

Biliary Anatomy Quiz: Test Your Knowledge.

One of the most common surgical procedures performed in the USA is the cholecystectomy. Understanding biliary anatomy, which includes the gallbladder and extrahepatic biliary tree, is essential for every general surgeon. This quiz includes clinically relevant anatomy and radiology questions for the current and future surgeon at every level of training, and we hope it will be a useful adjunct to one's review.

Biliary variations and biliary complications in living donor liver transplantation.

BACKGROUND/AIMS: To evaluate the relationship between biliary complications of recipients and biliary variations of donors in living donor liver transplantation. METHODOLOGY: From January 2008 to February 2011, 60 adult patients underwent LDLT at West China Hospital, Sichuan University, China. After cholecystectomy, an intraoperative cholangiogram was routinely performed through the cystic duct to identify biliary anatomy. The recipients have been followed up for 3 to 40 months. RESULTS: Biliary complications developed in 9 patients (15.0%) and 3 (5.0%) were diagnosed as anastomotic leakage, while 6 (10.0%) developed strictures. The incidence of biliary variations was 26%. There was no statistical difference in biliary complications no matter the biliary variations. CONCLUSIONS: Performing biliary variations assessment may contribute to reduction of biliary complications.

Anatomic variations of the extrahepatic biliary tree. A monocentric study and review of the literature.

INTRODUCTION: The study of the anatomy of the extra hepatic bile ducts has demonstrated the existence of a significant number of variants which can be explained by hepato-biliary embryology. A good knowledge of this anatomy is essential for the interpretation of radiological examinations, and for a good practice of hepato-biliary and pancreatic surgery. Several imaging methods are used to study the anatomy of the bile ducts, including classical cholangiography, which is still practiced and very useful. AIM: To study the modal anatomy (the most frequent) and the anatomical variants of the extrahepatic bile ducts through the interpretation of postoperative cholangiograms and to examine their implication on the surgical practice. METHODS: This is a monocentric, retrospective observational study. It concerned any patient who underwent hepato-biliary or pancreatic surgery at the Department of General and Digestive Surgery of Farhat Hached University Hospital of Sousse between 2007 and 2016, and who received postoperative cholangiography. A data form was fulfilled for each patient. RESULTS: Out of a total population of 293 patients, we identified 158 patients (53.9%) with anatomic variants of the extrahepatic bile ducts. The common bile duct was modally implanted in the second duodenum in 96.2% of cholangiographies and in the genu inferius in 3.8% of cases. The main pancreatic duct had a V-shaped implantation in 87.1% of cholangiograms, a U-shaped implantation in 4.2% of cases and a Y-shaped implantation in 7.1% of cases. The common bile duct had a modal aspect in 71.3% of cholangiograms, with 28.7% of anatomic variants, organized in 4 models. The cystic duct had a modal presentation in 80.9% of cases, and we recorded 6 other branching models (19.1% of cases). No significant difference was observed between the presence of anatomic variants on the one hand, and age, sex, conversion rate, intraoperative incidents, postoperative complications, postoperative hospital stay and overall hospital stay on the other hand. CONCLUSION: Conventional cholangiography constitutes a more or less precise tool for detecting these anatomic variants and is therefore very useful in the practice of hepato-biliary surgery even after the advent of new techniques in this field. However, it also requires a more extensive and in-depth knowledge of these anatomic variants, which nevertheless remain quite frequent, and represent a source of surgical difficulties.

Radiologic Evaluation and Structured Reporting Form for Extrahepatic Bile Duct Cancer: 2019 Consensus Recommendations from the Korean Society of Abdominal Radiology.

Radiologic imaging is important for evaluating extrahepatic bile duct (EHD) cancers; it is used for staging tumors and evaluating the suitability of surgical resection, as surgery may be contraindicated in some cases regardless of tumor stage. However, the published general recommendations for EHD cancer and recommendations guided by the perspectives of radiologists are limited. The Korean Society of Abdominal Radiology (KSAR) study group for EHD cancer developed key questions and corresponding recommendations for the radiologic evaluation of EHD cancer and organized them into 4 sections: nomenclature and definition, imaging technique, cancer evaluation, and tumor response. A structured reporting form was also developed to allow the progressive accumulation of standardized data, which will facilitate multicenter studies and contribute more evidence for the development of recommendations.

Anatomical variations of the extrahepatic ducts in dogs: knowledge for surgical procedures.

Variations of the hepatic duct terminal were examined in 50 cadavers of mixed-breed dogs. The hepatic duct was formed by 4 major tributaries in 70% of the dogs and by 3 tributaries in 30% of the dogs. The order of hepatic duct termination, proximal to the gallbladder, was as follows: the duct from the right medial lobe, then the quadrate, then the common duct from the right lateral and caudate lobes and finally the duct from the left lobes in most of the dogs (90%). In only 10% of the dogs, the duct from the quadrate lobe terminated proximal to the duct from the right medial lobe. The length of the cystic duct was more than 5 mm in most dogs (88%). This study showed anatomical variations of the extrahepatic biliary tree and their preoperational imaging. These results may be useful for shortening the operative period and provide basic information for the application of laparoscopic cholecystectomies.

Anatomical variations and congenital anomalies of extra hepatic biliary system encountered during laparoscopic cholecystectomy.

OBJECTIVE: To assess the frequency of anatomical variations of extrahepatic biliary system in patients undergoing laparoscopic cholecystectomy. METHODS: This is an observational study performed in the Department of Surgery, Liaquat University of Medical and Health Sciences, Jamshoro for a period of four years from January 2004 to December 2007. All diagnosed patients of cholelithiasis undergoing routine laparoscopic cholecystectomy were assessed for anatomical/congenital extra hepatic biliary and vascular anomalies. Structures mainly assessed for anomalies were gall bladder, cystic duct, supraduodenal part of Common Bile Duct (CBD), cystic artery and hepatic artery which are routinely handled during laparoscopy. However, assessment of variations and anomalies, of hepatic ducts, portal vein, retroduodenal and pancreatic parts of CBD were not done due to possibility of iatrogenic injuries. RESULTS: Three hundred cases of cholelithiasis comprising 255 (85%) females and 45 (15%) males with mean age of 39.85 +/- 18.82 years were included in the study. Patients mainly presented with upper abdominal pain including pain in right hypochondrium (71.67%), pain in right hypochondrium and epigastrium (19%) and pain in epigastrium alone (9.33%) as main symptoms. Operative findings revealed variations in 61 (20.33%) patients mainly involving cystic artery (10.67%), cystic duct (4.33%), right hepatic artery (2.67%) and gallbladder (2%). Postoperatively 3.67% revealed bleeding and 1.67% biliary leak from drain as main complications related to anatomical variations giving rise to 1% morbidity, however, no mortality was seen in this series. CONCLUSION: Congenital anomalies and normal variants of biliary tree, are not common but may be of significance during laparoscopic surgery as failure to recognize them leads to iatrogenic injuries and can increase morbidity and mortality.

Importance of Rouviere's sulcus in laparoscopic cholecystectomy.

Background: Rouviere's sulcus is a 2-5 cm fissure on the liver between the right lobe and caudate process. The benefit of finding the Rouviere's sulcus during laparoscopic cholecystectomy is supported by the fact that the cystic duct and artery lay anterosuperior to the sulcus, and the common bile duct (CBD) lays below the level of the Rouviere's sulcus. Hence, it can serve as an extrabiliary anatomical reference point during laparoscopic cholecystectomy to identify the location of CBD. Materials and Methods: This prospective observational study was carried out on 99 patients during a period of 1 year. During laparoscopic cholecystectomy, Rouviere's sulcus was identified after retracting the fundus of the gallbladder toward the right shoulder. Its morphology in terms of open type, close type, or scar-like shapes was recorded, and if the CBD outline could be visualized, then its relation with the Rouviere's sulcus was noted. Results: Among all 99 study patients, Rouviere's sulcus could be identified in 63 cases (63.63%), whereas it could not be seen in 36 cases (36.36%) (P < 0.007). It was of open type in 68.25% (43 cases), close type in 25.39% (16 cases), and scar like in 6.35% (4 cases) (P < 0.0001). The Rouviere's sulcus was found to be above the level of CBD line in 50 patients (79.36%) and at the same level in 11 patients (17.46%), and in two patients, (5.97%) CBD line could not be visualized. Conclusion: Identification of Rouviere's sulcus during laparoscopic cholecystectomy can serve as an additional reference point to avoid major bile duct injury. In the era of laparoscopy, it can be better visualized after creating the pneumoperitoneum and retracting the fundus of the gallbladder.

RésuméContexte: Le sulcus de Rouvière est une fissure de 2 à 5 cm sur le foie entre le lobe droit et le processus caudé. L'avantage de trouver la Rouvière sulcus au cours de la cholécystectomie laparoscopique est soutenu par le fait que le canal cystique et l'artère sont antéro-supérieurs au sulcus, et le le canal cholédoque (CBD) se situe sous le niveau du sulcus de Rouvière. Par conséquent, il peut servir de point de référence anatomique extrabiliaire pendant la cholécystectomie laparoscopique pour identifier l'emplacement du CBD. Matériels et méthodes: Cette étude observationnelle prospective a été réalisée sur 99 patients pendant une période de 1 an. Au cours de la cholécystectomie laparoscopique, le sulcus de Rouvière a été identifié après rétractation le fond de la vésicule biliaire vers l'épaule droite. Sa morphologie en termes de type ouvert, fermé ou cicatriciel a été enregistrée, et si le contour CBD pouvait être visualisé, alors sa relation avec le sulcus de Rouvière était notée. Résultats: parmi les 99 patients de l'étude, Le sulcus de Rouvière a pu être identifié dans 63 cas (63,63%), alors qu'il n'était pas visible dans 36 cas (36,36%) (p <0,007). C'était ouvert type dans 68,25% (43 cas), type proche dans 25,39% (16 cas), et cicatrice comme dans 6,35% (4 cas) (p <0,0001). Le sulcus de la Rouvière a été retrouvé être au-dessus du niveau de la lignée CBD chez 50 patients (79,36%) et au même niveau chez 11 patients (17,46%), et chez deux patients, (5,97%) CBD la ligne n'a pas pu être visualisée. Conclusion: l'identification du sulcus de Rouvière lors de la cholécystectomie laparoscopique peut servir de point de référence pour éviter une lésion majeure des voies biliaires. À l'ère de la laparoscopie, il peut être mieux visualisé après la création du pneumopéritoine et rétractant le fond de la vésicule biliaire.

Hilar liver resection in dogs.

OBJECTIVE: To describe hepatic vasculobiliary anatomy important to hilar liver lobe resection in the dog. STUDY DESIGN: Experimental study. ANIMALS: Canine cadavers (n=7). METHODS: The vasculobiliary system of 7 fresh canine livers was injected with a polymer. The parenchyma was dissected at the level of the hilus to determine the vascular and biliary supply to each liver lobe, and then macerated with a corrosion preparation. The information gathered was used to describe a surgical approach for hilar liver lobe resection. RESULTS: Each liver lobe had a single hepatic artery and biliary duct. The location of these structures was consistent, although minor variations existed (dorsal versus ventral to the lobar portal vein) in the left lateral lobe and papillary process in 2 specimens. Most liver lobes (34/49) were supplied by 1 lobar portal vein and drained by 1 lobar hepatic vein (39/49). The location of the portal and hepatic veins was consistent among specimens. CONCLUSIONS: The left division is the most mobile of the liver lobes and each lobe can be removed separately or en bloc. Because of the location of the hepatic veins, the central division is best removed as a single unit. The right lateral lobe can be removed individually or together with the caudate process. The papillary process is removed by itself. CLINICAL RELEVANCE: A hilar liver lobectomy technique can provide an alternative approach to conventional procedures for tumors that encroach upon the hilus of the liver.