Anatomical Variations of Cystic Ducts in Magnetic Resonance Cholangiopancreatography and Clinical Implications

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

A Case of Postoperative Biliary Leak in a Patient With Duplicated Cystic Ducts

Duplicated cystic ducts are a rare congenital malformation with less than 20 reported cases before 2019. This malformation is important to identify to reduce the risk of intraoperative complications such as bile duct injuries that can increase postoperative morbidity and mortality. We present the case of a 62-year-old male with duplicated cystic ducts that were ligated during laparoscopic cholecystectomy and subsequently complicated by postoperative biloma formation. Treatment options for biliary leak include endoscopic retrograde cholangiopancreatography (ERCP) with stenting, percutaneous drainage, and duct embolization. Each carries the risk of complications such as infection, duct perforation, and stent/drain displacement. Roux-en-Y hepaticojejunostomy (RHYJ) tends to be the last resort when other minimally invasive procedures fail. It is imperative to identify postoperative complications related to cystic duct anomalies and the various treatment options available should these complications occur.

Variations in the cystic duct: frequency and the relationship among insertion sides and heights on the bile duct

BACKGROUND

Evaluation of the cystic duct anatomy prior to bile duct or gallbladder surgery is important, to decrease the risk of bile duct injury. This study aimed to clarify the frequency of cystic duct variations and the relationship between them.

METHODS

Data of 205 patients who underwent cholecystectomy after imaging at Sada Hospital, Japan, were analyzed. The Chi-square test was used to analyze the relationships among variations.

RESULTS

The lateral and posterior sides of the bile duct were the two most common insertion points (92 patients, 44.9%), and the middle height was the most common insertion height (135 patients, 65.9%). Clinically important variations (spiral courses, parallel courses, low insertions, and right hepatic duct draining) relating to the risk of bile duct injury were observed in 24 patients (11.7%). Regarding the relationship between the insertion sides and heights, we noticed that the posterior insertion frequently existed in low insertions (75.0%, P < 0.001) and did not exist in high insertions. In contrast, the anterior insertion coexisted with high and never low insertions. Spiral courses have two courses: anterior and posterior, and anterior ones were only found in high insertion cases.

CONCLUSIONS

The insertion point of the cystic duct and the spiral courses tended to be anterior or lateral superiorly and posterior inferiorly. Clinically significant variations in cystic duct insertions are common and surgeons should be cautious about these variations to avoid complications.

Biliary Anatomy 2.0 Quiz: Test Your Knowledge

Anatomy has remained an interest of physicians throughout the ages. The biliary tract spans from the liver to the hepatoduodenal mesentery, pancreas, and into the duodenum. Therefore, it is important for not only hepatobiliary surgeons but also general gastrointestinal surgeons, gastroenterologists, radiologists, and pathologists to be familiar with biliary anatomy and its variants. While surgery for hilar cholangiocarcinoma is one of the most challenging procedures, cholecystectomy is one of the most common procedures done from the beginning of surgical training. We hope that by answering the following questions, you will gain a comprehensive understanding of biliary anatomy and a greater appreciation for it.

Biliary balloon dilator impaction in a non-dilated bile duct with anatomical variations: a case report

BACKGROUND

While techniques for extracting large stones from dilated bile ducts are increasing, options for small stones impacted in non-dilated bile ducts are limited.

CASE PRESENTATION

We report the case of an impacted biliary balloon dilator in a choledocholithiasis patient with a non-dilated bile duct and multiple anatomical variations, including low insertion of the cystic duct. After unsuccessful attempts with a stone extraction basket and balloon, a biliary balloon dilator with a sharp catheter tip was advanced into the bile duct. The balloon could not be removed from the bile duct even when deflated. The duodenoscope fell back into the stomach, causing the shaft of the dilator to break near the ampulla. We then removed the broken tip with a snare, which caused the balloon sheath to separate from the shaft and remain in the bile duct. Finally, we removed the sheath with rat-tooth forceps, leading to successful extraction of the stone-and-balloon complex.

CONCLUSIONS

The exceedingly rare possibility of balloon impaction should be kept in mind when using biliary balloon dilators in non-dilated bile ducts.

Cystic duct cyst in adults: a systematic review of the sixth entity

Over the past two decades, there have been an increasing number of reports describing a sixth type of choledochal cyst (cystic duct cyst) in adults that was not included in Todani's classification. This sixth entity has not yet been systematically reviewed in the literature. We therefore explored this condition in adults from the perspective of the clinical presentation, diagnosis and treatment through a systematic review of the evidence. The final analysis included 33 reported cases, with 55% of them reported in Asia. The mean age was 39.3 years old, with a female-to-male ratio of 1.5:1. Magnetic resonance cholangiopancreatography was accurate in establishing the diagnosis in 69% of cases. Where reported, standard laparoscopic/open cholecystectomy was performed in about 74% of patients, while around 25% of them needed extensive surgery. Associated malignancy was reported in 6.1% of cases, while 28% of patients had co-existent gallstone-related disease. No significant post-operative morbidity or mortality was reported. In this era of emergency laparoscopic cholecystectomy, surgeons should be aware of this rare condition, with the particular understanding that it is associated with gallstone-related disease in a significant number of reported cases.

Anatomic Variations of the Cystic Duct in Magnetic Resonance Cholangiopancreatography in Shiraz: A Cross-Sectional Study

BACKGROUND

Anatomic variations of the cystic duct (CD) are commonly encountered. Being aware of these variants will reduce complications subsequent to surgical, endoscopic, or percutaneous procedures. Magnetic resonance cholangiopancreatography (MRCP) is the least invasive and the most reliable modality for biliary anatomy surveys. This study aimed to determine the prevalence of cystic duct variations in the Iranian population.

METHODS

In this retrospective cross-sectional study, MRCP images of 350 patients referred to Shiraz Faraparto Medical Imaging and Interventional Radiology Center from October 2017 to October 2018 were reviewed. The CD course and insertion site to the extrahepatic bile duct (EHBD) was determined and documented in 290 cases. Descriptive statistics and Chi square test were applied for data analysis via SPSS software.

RESULTS

About 77% of cases revealed the classic right lateral insertion to the middle third of EHBD. The insertion of CD to the upper third and the right hepatic duct was 10%, and the insertion to the medial aspect of the middle third of EHBD from anterior or posterior was noted to be about 7.6%. From 2.8% of insertions to the lower third, 1% demonstrated parallel course, and finally, 0.3% of cases presented short CD.

CONCLUSION

CD variations are relatively common, and MRCP mapping prior to the hepatobiliary interventions could prevent unexpected consequences.

The effect and importance of extrahepatic bile duct anatomy variations in the etiology of choledocholithiasis

Background: Biliary stone disease is a frequently encountered problem among the population with a variety of causes and resulting in a wide range of symptoms from vague abdominal discomfort to life-threatening conditions requiring urgent surgical intervention. Magnetic resonance cholangiopancreatography (MRCP) has become a noninvasive radiological diagnostic method extensively used in the evaluation of the biliary tract providing excellent anatomical detail. Apart from the classical causes widely described in the literature in stone etiology, the effect of anatomical variations of the bile tract is a subject that has been investigated recently. The present study aimed to manifest the effect of anatomical variations of the extrahepatic biliary tract on the etiology of choledocholithiasis. Methods: The data of 182 patients who underwent MRCP in our hospital between 2016 and 2021 were retrospectively scanned. The patients were divided into two groups, asymptomatic patients and acute cholangitis. Cystic duct, common hepatic duct, choledochal lengths, and variations in cystic duct opening were analyzed by an experienced radiologist in MRCP. Results: The relation was detected between the cystic choledochal variance of the patients (p<0.001). The cystic duct length of the patients showed statistically significant differences (p<0.05). Conclusion: When the extrahepatic bile duct variations were evaluated, some notable values were found for the etiology, as well as being critical in acute cholangitis. There is a need for studies with larger sample sizes in the literature on this subject.

Anatomical variations of cystic duct insertion and their relationship with choledocholithiasis: an MRCP study

Background

The frequency of insertion variations of cystic duct (CD) is inconsistent between studies caused to some extent by the way they give the relative frequency of the variations. Moreover, certain insertion variations have been reported to be associated with choledocholithiasis. This study aimed to assess the frequency of CD insertion variations with a comprehensive way of classification in an unselected population in whom MRCP was performed. Moreover, the relationship between the types of variant insertions and choledocholithiasis using MRCP was also assessed. Patients undergoing magnetic resonance cholangiopancreatography (MRCP) were reviewed retrospectively by two radiologists who were blinded to the clinical data. The normal insertion was defined as the union through middle one third of the lateral border of the extrahepatic bile duct. The transverse site (lateral, medial, anterior, and posterior) and the craniocaudal level (high, mid and low) of insertions and their intersections were assessed using axial and coronal slices, respectively. In addition, the frequencies of the CD insertion variations were compared between choledocholithiasis and control (no-choledocholithiasis) groups.

Results

A total of 307 patients (124 with choledocholithiasis and 183 controls) were analyzed. A true variant insertion was found in 149 (48.5%) cases. The insertion variations were less frequent in the choledocholithiasis group [50 (40.3%) vs. 99 (54.1%), respectively, p = 0.018]. The frequencies of craniocaudal level of insertion differed significantly between groups (p = 0.014) that was driven by a lower rate of low medial insertion (1.6% vs. 9.8%, respectively) in the choledocholithiasis group. The frequencies of transverse site of insertion were similar between groups (p = 0.314). The low medial insertion was 80.7% less likely associated with choledocholithiasis even after adjustment for age (Odds ratio: 0.193, 95% Confidence interval: 0.039–0.954, p = 0.044). The interreader agreement for insertion assessment was good (Cohen’s Kappa: 0.748, p < 0.001).

Conclusions

The prevalence of CD insertion variations in an unselected population undergoing MRCP is quite high and a mid-posterior insertion is the most common variant type. Insertion variations of CD, the low medial insertion in particular, are less common in patients with choledocholithiasis than controls.

Low insertion of cystic duct increases risk for common bile duct stone recurrence

BACKGROUND

Common bile duct (CBD) stone is one of the most frequent biliary diseases. Recurrence after the complete removal of CBD stones is high, and we aim to evaluate the rate and risk factors for symptomatic recurrence of CBD stones after endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

We, retrospectively, reviewed the database of patients who underwent ERCP for CBD stones and subsequent cholecystectomy between January 2015 and December 2017 at a tertiary hospital. The recurrence of symptomatic CBD stones was defined as the presence of a CBD stone with related symptoms at least 6 months after the ERCP procedure. The primary outcomes were recurrence of symptomatic CBD stones and its risk factors.

RESULTS

Among the 362 enrolled patients, 60 experienced a symptomatic recurrence of CBD stones between 6 months and 5 years after the procedure. The mean duration of follow-up was 32.3 ± 8.1 months. The patients with recurrences were older and had a longer follow-up duration. Low insertion of the cystic duct (HR = 2.893, p = 0.016), distal CBD angulation (HR = 1.015, p = 0.034), maximum CBD diameter (HR = 1.070, p = 0.012), number of ERCP sessions at first admission (HR = 1.558, p = 0.032), and cannulation time (HR = 1.030, p = 0.008) were the independent risk factors for symptomatic recurrent CBD stones.

CONCLUSIONS

Patients with risk factors, especially those with low cystic duct insertion, are more prone to symptomatic recurrent CBD stones and should be followed more carefully.

Choledochal cyst and aberrant biliary configuration along with situs inversus totalis: a case report

Situs inversus totalis is the complete transpositioning of thoracoabdominal viscera into a mirror image of the normal configuration. Choledochal cyst is the congenital cystic dilation of the biliary tract. Both these conditions coexisting in a patient is extremely rare. We hereby present a case of type IC choledochal cyst in a patient with situs inversus totalis presenting with biliary sepsis secondary to choledocholithiasis. Also detailed are the management and operative strategies employed to deal with this rare entity.

3D-printed anatomical models of the cystic duct and its variants, a low-cost solution for an in-house built simulator for laparoscopic surgery training

OBJECTIVES

To explore a method to create affordable anatomical models of the biliary tree that are adequate for training laparoscopic cholecystectomy with an in-house built simulator.

METHODS

We used a fused deposition modeling 3D printer to create molds of Acrylonitrile Butadiene Styrene (ABS) from Digital Imaging and Communication on Medicine (DICOM) images, and the molds were filled with silicone rubber. Thirteen surgeons with 4-5-year experience in the procedure evaluated the molds using a low-cost in-house built simulator utilizing a 5-point Likert-type scale.

RESULTS

Molds produced through this method had a consistent anatomical appearance and overall realism that evaluators agreed or definitely agreed (4.5/5). Evaluators agreed on recommending the mold for resident surgical training.

CONCLUSIONS

3D-printed molds created through this method can be applied to create affordable high-quality educational anatomical models of the biliary tree for training laparoscopic cholecystectomy.

A Double Cystic Duct With a Single Gallbladder Successfully Treated With Laparoscopic Cholecystectomy: A Challenge to Laparoscopic Surgeons

Although the cystic duct has diverse variations, a double cystic duct is rarely found. Only 20 cases had been reported until late 2017. In the present study, we describe a 58-year-old woman with a double cystic duct who initially presented with a passed stone and pancreatitis concomitant with a gallbladder containing microlithiasis. The double cystic duct was not detected in preoperative endoscopic ultrasonography; and the anomaly was an incidental finding during laparoscopic cholecystectomy. The patient had no postoperative complications and was discharged uneventfully. Postoperative magnetic resonance cholangiography showed a normal biliary tree structure.

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.

Risk of Gallstone Formation in Aberrant Extrahepatic Biliary Tract Anatomy: A Review of Literature

The age-long mnemonic of '5Fs' (fat, female, fertile, forty, and fair) has traditionally been used in medical school instructions to describe the risk factors for gallstone disease. However, evidence suggests that aberrant extrahepatic biliary tract (EHBT) anatomy may contribute significantly to the risk of gallstone disease. This review explores the anatomy and embryological bases of EHBT variations as well as the prevalence of these variations. Also, we discuss the risk factors for gallstone formation in the relationship between gallstone disease and aberrant EHBT anatomy.

Biliary anatomy and pancreatic duct variations: A cross-sectional study

BACKGROUND/AIM

Biliary tree and pancreatic duct can appear in different variations whose proper understanding is obligatory for surgeons. Magnetic resonance cholangiopancreatography (MRCP) is considered a safe and accurate tool for evaluating biliary tree and pancreatic duct. Typical anatomy for right hepatic duct (RHD) and left hepatic duct (LHD) is reported as 57% and 63%, respectively. The most common (4-10%) pancreatic anomaly is divisum. In the present study, we evaluated and determined the prevalence of biliary tree and pancreatic duct variations among patients at a university hospital.

MATERIALS AND METHODS

The MRCP records of 370 patients from 2015 to 2017 were obtained for cross-sectional study. Images were retrospectively reviewed for variations by two independent senior radiologists. Demographic data were obtained for all the patients. Huang et al. classification was used for RHD and LHD variations. The cystic duct was reported based on its course and insertion pattern. The pancreatic duct was observed for the presence of divisum, its course, and configuration.

RESULTS

Three hundred and twenty-five patients were included in the final study. Most commonly observed variant for RHD were A1 (34.2%) and A2 (32.2%). For LHD, B1 (71.4%) was the most common variant. Cystic duct insertion was commonly seen as right lateral insertion (27.7%). Pancreatic divisum was observed in 0.6% of cases. Nationality, origin, and gender-specific variations were obtained.

CONCLUSION

Variations in biliary anatomy and pancreatic duct are very diverse and extend from the intrahepatic biliary system down to the pancreas. Performing a similar study on a larger population is mandatory to illustrate the range of variations present within the community.

A Rare Case of a Left-sided Gallbladder Accompanied with an Aplastic Cystic Duct in a Patient with Acute Cholecystitis

BACKGROUND A left-sided gallbladder without situs inversus is a rare congenital anomaly of the gallbladder with a prevalence ranging from 0.04-0.3%. CASE REPORT We present a case of a female patient, referred to our clinic with clinical features of an acute cholecystitis. After performing the standard preoperative investigations, which confirmed the diagnosis, the patient underwent a laparoscopic cholecystectomy. We found a left-sided gallbladder, attached to the lower surface of the left lobe of the liver. During the dissection in the Callot triangle an aplastic cystic duct was also identified. The extirpation of the gallbladder was performed anterograde, allowing a better exposition of the critical structures. CONCLUSIONS A left sided gallbladder is almost an incidental finding, which can be accompanied with further anomalies of the biliary tree. A combination of these 2 variations is very rare without any other reported cases in the literature.

Cholecystohepatic Duct: A Biliary Duct Variant Resulting in Postcholecystectomy Bile Leak-Case Report and Review of Normal and Common Variant Biliary Anatomy

Although relatively infrequent, bile duct leaks are among the primary complications of hepatobiliary surgery and cholecystectomy given the large number of these operations performed annually around the world. Variant biliary anatomy increases the risk of surgical complications, especially if unrecognized on preoperative imaging or intraoperatively. Presented here is a case of a patient with an unrecognized cholecystohepatic duct at the time of surgery leading to bile leak after cholecystectomy. Numerous factors made for a technically difficult surgery with obscuration of the true anatomy, ultimately resulting in transection of the cholecystohepatic duct. Understanding normal and variant biliary anatomy will help prevent avoidable complications of hepatobiliary surgery.

Evaluation of intrahepatic and extrahepatic biliary tree anatomy and its variation by magnetic resonance cholangiopancreatography in Odisha population: a retrospective study

Intrahepatic and extrahepatic anatomical knowledge is essential for pre procedural planning of liver transplantation, liver resection, complex biliary reconstruction and radiological biliary tree intervention. Indian data of biliary anatomy and its variation is scant in literature. The aim of our study is to find out the prevalence of common and uncommon pattern of biliary tree anatomy in magnetic resonance cholangiopancreatography (MRCP) in our population. A total of 1,038 cases of MRCP of population of Odisha were obtained from Picture Archiving and Communication System of the department and were reviewed by two senior radiologists for anatomical pattern and variations. The typical and most common pattern of right hepatic duct (RHD) branching was seen in 72.8% cases. The most common variant of RHD was trifurcation pattern of insertion of right anterior sectoral duct (RASD), right posterior sectoral duct and left hepatic duct (LHD) forming common hepatic duct (CHD) in 11.3% of cases. The common trunk of segment (SEG) II and III ducts joining the SEG IV duct was the most common LHD branching pattern in 90.3% of cases. The most common pattern of cystic duct was posterior insertion to middle third of CHD (42.8%). MRCP is the non-invasive imaging modality for demonstration of biliary duct morphology to prevent iatrogenic injury during hepatobiliary intervention and surgery.

A case report on a rare anatomic variant of cystic duct insertion

We report a case a 70-year-old female presenting with abdominal pain who has a cystic duct coursing medial to the common bile duct before anastomosing just proximal to the ampulla. Low medial insertion of the cystic duct is a rare anatomic variant that is easily misidentified on imaging studies and may complicate surgical and percutaneous intervention. It can be identified by pre-operative imaging modalities such as magnetic resonance cholangiopancreatography.