Evaluation of aberrant bile ducts before laparoscopic cholecystectomy: helical CT cholangiography versus MR cholangiography

Access and reattachment of biliary tree anomaly through Roux-en-Y hepaticojejunostomy: A case report

The right posterior segmental duct (RPSD) draining into the cystic duct is exceedingly rare. Ligation of the cystic duct in proximity to the junction of an aberrant right hepatic duct after a cholecystectomy can lead to life threatening complications. The present case study reveals a severed anomalous RPSD and subsequent Roux-en-Y hepaticojejunostomy procedure employed to fix biliary anomaly.

Double Cystic Duct: Preoperative use of MRCP Without Being Aware of the Anatomic Anomaly: A Case Report

Introduction

A biliary anomaly is occasionally encountered, however, a double cystic duct is exceedingly rare during surgery. It is pivotal for surgeons to recognize the anatomic variations in Cholangiography which is performed under fluoroscopic guidance Intraoperatively to prevent possible complications.

Case Presentation

Herein, the case of a 66-year-old female patient with acute cholecystitis, in which preoperative Magnetic Resonance Cholangiopancreatograph (MRCP) did not identify a single gallbladder with double cystic ducts, is presented. Intraoperatively we identified a double cystic duct and it was safely ligated with clips. Anatomic variability was also confirmed by Cholangiography which was performed under fluoroscopic guidance. Furthermore, the patient was symptom-free through 1 year of follow-up assessment.

Conclusions

In particular, when we do not identify anatomic variability based on imaging, cholangiography under fluoroscopic guidance during surgery was a powerful tool that may clearly show the anomaly of a single gallbladder with double cystic ducts.

Modified and dynamic intraoperativecholangiography during laparoscopic cholecystectomy in two patients with aberrant right posterior hepatic duct

Aberrant right posterior hepatic duct (ARPHD) is one of the anatomical anomalies of the bile duct. It is a risk factor for bile duct injury during laparoscopic cholecystectomy (LC). ARPHD can be diagnosed before surgery by magnetic resonance cholangiopancreatography or drip infusion cholangiographic-computed tomography. However, it is not easy to identify ARPHD during LC. Classic intraoperative cholangiography (IOC) procedure that does not lead to bile duct injury avoidance needs to be modified. In modified IOC, cannulation is performed from the infundibulum or neck of the gallbladder. We reported a modified and dynamic IOC procedure that can identify ARPHD safely and precisely during LC. The modified IOC provided direct evidence of no injury to ARPHD in 2 cases.

Diagnosis of a single gallbladder with double cystic ducts and dominant accessory duct draining into the right hepatic duct: a case report

Biliary anomalies are a high risk for biliary injury during surgery, and although a biliary anomaly is occasionally encountered, variations in cystic ducts are rare. A preoperative diagnosis is highly valuable in facilitating surgical procedures and avoiding surgical complications. Herein, the case of a 67-year-old female patient with acute cholecystitis, in which preoperative fluoroscopic cholangiography clearly demonstrated a single gallbladder with double cystic ducts, is presented. The accessory duct was found to be dominant, draining into the otherwise normal right intrahepatic bile duct, and laparoscopic cholecystectomy was performed smoothly and successfully. Fluoroscopic cholangiography is a powerful tool that may clearly depict the anomaly of a single gallbladder with double cystic ducts. Through appropriate preoperative knowledge and demonstration of this biliary anomaly in the present case, laparoscopic cholecystectomy was safely performed, and the patient was symptom-free at the 3-year follow-up assessment.

Successful diagnosis and treatment of double common bile duct with cholelithiasis by laparoscopic cholecystectomy

Double common bile duct (DCBD) is an extremely rare congenital anomaly of the biliary system associated with serious complications. An association between DCBD and inadvertent bile duct injury during surgery has been reported. However, DCBD is difficult to diagnose preoperatively. We report a rare case of DCBD (type 3b), combined with cholelithiasis and cholecystitis, diagnosed preoperatively, and treated safely by laparoscopic cholecystectomy. A 79-year-old woman was admitted with a 1-week history of chest pain. Abdominal computed tomography revealed gallbladder distension with obvious wall thickening. Laparoscopic cholecystectomy was planned to determine the presence of stones in the common bile duct and an anomalous biliary tract. Magnetic resonance cholangiopancreatography (MRCP) was performed, and anomalous anatomy of the biliary tract was suspected. Drip infusion cholangiography with computed tomography (DIC-CT) showed type 3b DCBD. On hospital day 7, laparoscopic cholecystectomy was performed without accessory common bile duct resection. The postoperative course was uneventful, and the patient was discharged on postoperative day 5. To our knowledge, this is the first report of the successful diagnosis of DCBD using DIC-CT. MRCP and DIC-CT can be useful for the pre-operative diagnosis of DCBD to decrease the risk of bile duct injury during surgery.

Laparoscopic cholecystectomy for a cholelithiasis patient with an aberrant biliary duct of B5: a case report

BACKGROUND

An aberrant biliary duct of segment 5 (B5) is a rare anomaly of the biliary tract. All anatomical anomalies of the biliary tract are risk factors for bile duct injury during surgery. We report a case of cholelithiasis with an aberrant B5 that was detected during a detailed preoperative imaging examination and treated with laparoscopic cholecystectomy.

CASE PRESENTATION

A 69-year-old woman was admitted to the emergency room of our hospital with abdominal pain. She was diagnosed with cholelithiasis, and an aberrant B5 branching off the hepatic duct was suggested during preoperative imaging. Laparoscopic cholecystectomy was performed at our surgical department. There were no intra- or postoperative complications, and the patient was discharged on the fourth day after surgery.

CONCLUSIONS

Laparoscopic cholecystectomy can be safely performed without intra- or postoperative complications in patients with cholelithiasis and an aberrant B5 if it is accurately diagnosed preoperatively.

A novel classification of aberrant right hepatic ducts ensures a critical view of safety in laparoscopic cholecystectomy

BACKGROUND

Based on the spatial relationship of an aberrant right hepatic duct (ARHD) with the cystic duct and gallbladder neck, we propose a practical classification to evaluate the specific form predisposing to injury in laparoscopic cholecystectomy (LC).

METHODS

We retrospectively investigated the preoperative images (mostly magnetic resonance cholangiopancreatography) and clinical outcomes of 721 consecutive patients who underwent LC at our institute from 2015 to 2018. We defined the high-risk ARHD as follows: Type A: communicating with the cystic duct and Type B: running along the gallbladder neck or adjacent to the infundibulum (the minimal distance from the ARHD < 5 mm), regardless of the confluence pattern in the biliary tree. Other ARHDs were considered to be of low risk.

RESULTS

A high-risk ARHD was identified in 16 cases (2.2%): four (0.6%) with Type A anatomy and 12 (1.7%) with Type B. The remaining ARHD cases (n = 34, 4.7%) were categorized as low risk. There were no significant differences in the operative outcomes (operative time, blood loss, hospital stay) between the high- and low- risk groups. Subtotal cholecystectomy was applied in four cases (25%) in the high-risk group, a significantly higher percentage than the low-risk group (n = 1, 2.9%). In all patients with high-risk ARHD, LC was completed safely without bile duct injury or conversion to laparotomy.

CONCLUSIONS

Our simple classification of high-risk ARHD can highlight the variants located close to the dissecting site to achieve a critical view of safety and may contribute to avoiding inadvertent damage of an ARHD in LC.

Intraoperative Bile Duct Disruption Treated Using Intrahepatic Biliary Ablation with Ethanol: A Report of Two Cases

We report two cases of intraoperative bile duct disruption. In case 1, an isolated bile duct in the remnant of the anterosuperior liver segment after right hepatic lobectomy for cholangiocarcinoma caused bile leakage. In case 2, bile leakage continued from a disrupted accessory hepatic duct during pancreaticoduodenectomy for pancreatic carcinoma. In both patients, a mixture of ethanol and iodized oil at a 10:1 ratio was injected into the disrupted bile duct under balloon occlusion. In case 1, the mixture was injected through a balloon catheter under balloon occlusion overnight. No severe complications developed in either case. Bile leakage stopped postoperatively and did not recur until the patients' death from tumor progression 14 and 16 months after surgery, respectively.

Ducts of Luschka as a rare cause of postoperative biloma. MRCP findings

Laparoscopic cholecystectomy can be complicated by a post- operative biloma. Bile leak from the duct of Luschka is reported to be the second most frequent cause, reported in 0.15%-2% of the patients. This case report aims to underline the significance of this anatomic variation and how the management of the aforementioned complication can be facilitated by MRI- MRCP. A 78 year old male patient underwent an elective laparoscopic cholecystectomy and was found to have a post-operative biloma. An MRCP was carried out to visualize the bile tree and bile leak was identified to be originated from a duct of Luschka. The patient was referred for an ERCP, sphingterotomy and placement of biliary stent to release the pressure in the bile ducts. In the next few days the bile leak was controlled and eventually ceased. The patient was discharged free of symptoms and no sign of bile leak was to be found on his follow up imaging. In comparison with other imaging modalities picturing the bile tree, MRCP fits the ideal profile to be used as a first line choice for clinicians, as it offers detailed anatomical images with high contrast between bile and adjacent tissues, without using any contrast agent or radiation.

Two Cases of Subvesical Bile Duct Injury Detected and Repaired Simultaneously during Laparoscopic Cholecystectomy

Introduction

Subvesical bile duct (SVBD) injury is a secondary major cause of minor bile duct injury after laparoscopic cholecystectomy (LC). However, this injury is usually not recognized intraoperatively, but postoperatively.

Case Report

Case 1: the patient was an 84-year-old female, preoperatively diagnosed with acute cholecystitis. During LC, a tiny hole in the gallbladder fossa from which bile juice oozing was confirmed. Suturing was performed laparoscopically. Case 2: the patient was an 81-year-old male, preoperatively diagnosed with cholelithiasis. Because of a previous history of gastrectomy, laparoscopic adhesiolysis around the gallbladder was performed. During dissection, a small amount of bile was oozing from the surface of the liver adjacent to the gallbladder fossa. Suturing was performed laparoscopically.

Conclusion

If a small amount of bile juice was detected, meticulous observation not only around the cystic duct stump but also the gallbladder fossa should be performed. Simultaneous laparoscopic suturing was feasible, and an ideal procedure against SVBD injury developed during LC.

Main right hepatic duct entering the cystic duct: a case report

Background

Risk factors for bile duct injury in laparoscopic cholecystectomy include severe inflammation at Calot’s triangle and aberrant bile duct variations. Knowledge of the various biliary anomalies and early identification may therefore assist in decreasing the rate of bile duct injury.

Case presentation

A 65-year-old woman was admitted with right hypochondrial pain and high fever. A diagnosis of acute calculous cholecystitis was made by radiological imaging. Magnetic resonance cholangiopancreatography revealed that the confluence of the right and left hepatic duct was unclear. Intraoperatively, the procedure was converted from a laparoscopic cholecystectomy to laparotomy because of unclear anatomy of the cystic duct with severe inflammation at Calot’s triangle. Furthermore, intraoperative cholangiography from Hartmann’s pouch showed the main right hepatic duct entering the cystic duct. Subtotal cholecystectomy was performed to avoid injuring the right hepatic duct.

Conclusion

Although an aberrant hepatic duct entering the cystic duct is not uncommon, the main right hepatic duct infiltrating the cystic duct is extremely rare. Preoperative and intraoperative evaluation of the biliary duct and awareness of aberrant biliary duct variations is important in preventing bile duct injury.

Evaluation of biliary anatomy in the caudate lobe using drip infusion cholangiography-computed tomography

PURPOSE

This study aimed to retrospectively evaluate the caudate branches (CBs), which are bile ducts originating from the caudate lobe (CL), using drip infusion cholangiography with computed tomography (DIC-CT).

METHODS

The confluence patterns of CBs were evaluated in 185 adult patients undergoing DIC-CT. The following bile duct features were evaluated: (a) number of depicted CBs; (b) identification of the caudate portion from which the CBs were derived; (c) identification of the confluence site of a CB; and (d) whether there was a difference in the confluence site of the CBs depending on the position of the right posterior hepatic duct (RPHD) and the portal vein (PV).

RESULTS

DIC-CT enabled detection of a total of 640 bile ducts from the CL in 185 patients, and the total number of CBs from the Spiegel lobe (SP), the paracaval portion, and the caudate process (CP) were 347 (54.2%), 112 (17.5%), and 181 (28.2%), respectively. In the SP, over 60% of CBs joined the left hepatic duct system (LHDS). The positional relationship between the RPHD and the PV was divided into a supra-portal course (n = 168) and an infra-portal course (n = 17). The number of CBs joining the LHDS was significantly different between a supra-portal course and an infra-portal course (p = 0.0484).

CONCLUSION

CBs were depicted by DIC-CT in 98.9% of the subjects, and a detailed evaluation was possible. The number of CBs joining the LHDS was associated with the position of the RPHD and the PV.

Intraoperative Treatment of Duct of Luschka during Laparoscopic Cholecystectomy: A Case Report and Revision of Literature

Background

Bile leakage still remains a serious complication during cholecystectomies. In limited cases, this complication may occur from injury of the so-called ducts of Luschka. These rare ducts are usually discovered intraoperatively, and their presence poses the risk of bile injury and clinically significant bile leak.

Presentation Case

We present a unique case of a 59-year-old male patient with acute cholecystitis. After removal of the gallbladder, thorough inspection of the hepatic bed was made and a little bile leak was identified from a duct of Luschka 1 cm away from the gallbladder hilum. We report on the use of endoscopic QuickClip Pro® clips (Olympus Medical Systems Corp., Tokyo, Japan) to avoid further more invasive treatment.

Discussion

Endoscopic retrograde cholangiopancreatography with sphincterotomy played a crucial role for diagnosis and treatment of bile leaks with success rate near 94%. Many authors have argued the role of relaparoscopy, Diagnosis may be intraoperatively but this option does not seem to occur very often; in fact, there is a lack of data in literature.

Conclusion

This is the first case report of bile leak from duct of Luschka treated during the cholecystectomies with endoscopic clip.

Diagnosing common bile duct obstruction: comparison of image quality and diagnostic performance of three-dimensional magnetic resonance cholangiopancreatography with and without compressed sensing

PURPOSE

This study aimed to evaluate image quality and diagnostic performance of a recently developed navigated three-dimensional magnetic resonance cholangiopancreatography (3D-MRCP) with compressed sensing (CS) based on parallel imaging (PI) and conventional 3D-MRCP with PI only in patients with abnormal bile duct dilatation.

METHODS

This institutional review board-approved study included 45 consecutive patients [non-malignant common bile duct lesions (n = 21) and malignant common bile duct lesions (n = 24)] who underwent MRCP of the abdomen to evaluate bile duct dilatation. All patients were imaged at 3T (MR 750, GE Healthcare, Waukesha, WI) including two kinds of 3D-MRCP using 352 × 288 matrices with and without CS based on PI. Two radiologists independently and blindly assessed randomized images.

RESULTS

CS acceleration reduced the acquisition time on average 5 min and 6 s to a total of 2 min and 56 s. The all CS cine image quality was significantly higher than standard cine MR image for all quantitative measurements. Diagnostic accuracy for benign and malignant lesions is statistically different between standard and CS 3D-MRCP.

CONCLUSIONS

Total image quality and diagnostic accuracy at biliary obstruction evaluation demonstrates that CS-accelerated 3D-MRCP sequences can provide superior quality of diagnostic information in 42.5% less time. This has the potential to reduce motion-related artifacts and improve diagnostic efficacy.

Prospective Evaluation of Precision Multimodal Gallbladder Surgery Navigation: Virtual Reality, Near-infrared Fluorescence, and X-ray-based Intraoperative Cholangiography

OBJECTIVE

We aimed to prospectively evaluate NIR-C, VR-AR, and x-ray intraoperative cholangiography (IOC) during robotic cholecystectomy.

BACKGROUND

Near-infrared cholangiography (NIR-C) provides real-time, radiation-free biliary anatomy enhancement. Three-dimensional virtual reality (VR) biliary anatomy models can be obtained via software manipulation of magnetic resonance cholangiopancreatography, enabling preoperative VR exploration, and intraoperative augmented reality (AR) navigation.

METHODS

Fifty-eight patients were scheduled for cholecystectomy for gallbladder lithiasis. VR surgical planning was performed on virtual models. At anesthesia induction, indocyanine green was injected intravenously. AR navigation was obtained by overlaying the virtual model onto real-time images. Before and after Calot triangle dissection, NIR-C was obtained by turning the camera to NIR mode. Finally, an IOC was performed. The 3 modality performances were evaluated and image quality was assessed with a Likert-scale questionnaire.

RESULTS

The three-dimensional VR planning enabled the identification of 12 anatomical variants in 8 patients, of which only 7 were correctly reported by the radiologists (P = 0.037). A dangerous variant identified at VR induced a "fundus first" approach. The cystic-common bile duct junction was visualized before Calot triangle dissection at VR in 100% of cases, at NIR-C in 98.15%, and in 96.15% at IOC.Mean time to obtain relevant images was shorter with NIR-C versus AR (P = 0.008) and versus IOC (P = 0.00000003). Image quality scores were lower with NIR-C versus AR (P = 0.018) and versus IOC (P < 0.0001).

CONCLUSIONS

This high-tech protocol illustrates the multimodal imaging of biliary anatomy towards precision cholecystectomy. Those visualization techniques could complement to reduce the likelihood of biliary injuries (NCT01881399).

Double cystic duct preoperatively diagnosed and successfully treated with laparoscopic cholecystectomy: A case report

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A single gallbladder with a double cystic duct is a very rare finding.

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MRCP showed strong suspicion of a single gallbladder with a double cystic duct and the definite diagnosis of a double cystic duct was made by ERC.

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Laparoscopic cholecystectomy could be successfully performed in combination with intraoperative cholangiography for double cystic duct.

Introduction

A single gallbladder with a double cystic duct is a very rare finding. In addition, few cases with this rare condition are preoperatively diagnosed. However, the preoperative confirmation or suspicion of this rare condition could facilitate safe laparoscopic cholecystectomy, which is a minimally invasive therapeutic modality for gallbladder disease. We herein present a case of gallstone disease in a patient with a double cystic duct who was preoperatively diagnosed and successfully treated with laparoscopic cholecystectomy.

Presentation of case

A 57-year-old woman was admitted to our hospital with epigastric pain. Gallstone disease in the gallbladder and common bile duct was diagnosed by ultrasonography and computed tomography. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiography (ERC) revealed that the aberrant cystic duct arose from the cystic duct and communicated with the intrahepatic bile duct of the posterior segmental branch. Laparoscopic cholecystectomy was successfully performed in combination with intraoperative cholangiography.

Discussion

If an anomaly of the biliary duct system is not identified during surgery, it may turn out to be a bile leak. The preoperative diagnosis of a double cystic duct allows laparoscopic cholecystectomy to be performed safely in combination with intraoperative cholangiography.

Conclusions

A single gallbladder with double cystic duct is a very rare anomaly. However, laparoscopic surgery can be facilitated by the use of preoperative and intraoperative images.

Magnetic resonance cholangiopancreatography evaluation of intrahepatic bile duct variations with updated classification

PURPOSE

Preoperative detection of intrahepatic bile duct (IHBD) variations is essential to reduce surgical morbidity and mortality rates. Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive and reliable method for demonstrating the normal IHBD anatomy and its variations. This retrospective study aimed to identify and classify novel variations, except those already reported in the literature, using MRCP.

METHODS

MRCP examinations, which were conducted in two different centers in the last five years, were retrospectively evaluated. IHBD variations were recorded with respect to the Yoshida classification. In addition, newly detected variations that were not included in this classification were identified and classified.

RESULTS

MRCP examinations of 2624 patients were screened, and 2143 were determined to be eligible for evaluation. Of 2143 patients, 987 were males (average age, 54±18 years) and 1156 were females (mean age, 57±17 years). In this study, 10 novel variations that were not included in the Yoshida classification were identified in 14 patients.

CONCLUSION

MRCP is an effective, reliable, and noninvasive imaging method for evaluating the IHBD anatomy and its variations. Novel variations described in this study may help to better understand the biliary anatomy.

Preoperative evaluation of accessory hepatic ducts by drip infusion cholangiography with CT

BACKGROUND

This retrospective study aimed to investigate the incidence of each type of accessory hepatic duct by drip infusion cholangiography with CT (DIC-CT).

METHODS

Five hundred sixty nine patients who underwent preoperative DIC-CT and laparoscopic cholecystectomy were reviewed. Accessory hepatic ducts were classified as follows: type I (accessory hepatic ducts that merged with the common hepatic duct between the confluence of the right and left hepatic ducts and the cystic duct confluence), type II (those that merged with the common hepatic duct at the same site as the cystic duct), type III (those that merged with the common bile duct distal to the cystic duct confluence), type IV (the cystic duct merged with the accessory hepatic duct), and type V (accessory hepatic ducts that merged with the common hepatic or bile duct on the left side).

RESULTS

Accessory hepatic ducts were observed in 50 patients. Type I, II, III, IV, and V accessory hepatic ducts were detected in 32, 3, 1, 11, and 3 patients, respectively. Based on their drainage areas, the accessory hepatic ducts were also classified as follows: a posterior branch in 22 patients, an anterior branch in 9 patients, a combination of posterior and anterior branches in 16 patients, a left-sided branch in 2 patients, and a caudate branch in 1 patient. None of the patients with accessory hepatic ducts suffered bile duct injuries.

CONCLUSION

There are a number of variants of the accessory hepatic duct. DIC-CT is useful to detect the accessory hepatic duct.

Presence of Aberrant Anatomy Is an Independent Predictor of Bile Duct Injury During Cholecystectomy

The aim of this study is to investigate the impact of an aberrant anatomy diagnosed with MR cholangiography on the occurrence of bile duct injury. Although many authors report that aberrant anatomy is a strong risk factor for the occurrence of bile duct injury during cholecystectomy, no reports have examined the incidence of aberrant anatomy and its association as an independent risk factor for bile duct injury while controlling for potential confounding factors. This study involved 1289 patients. All images of MR cholangiography were reviewed and the findings, including the presence of aberrant anatomy, thickening of the gallbladder wall, and cystic duct stones—which may be related to the occurrence of bile duct injury—were recorded. The surgical outcome was compared according to the presence or absence of an aberrant anatomy and the predictive factors for bile duct injury were investigated. Aberrant anatomy was present in 11.2% of cases. The incidence of bile duct injury was significantly higher in patients with aberrant anatomy compared with patients without (3.5% versus 0.3%). By multivariate analysis, the presence of an aberrant anatomy and thickening of the gallbladder wall was an independent predictor for bile duct injury occurrence [odds ratio (OR) =16.56, P = 0.001; OR = 10.96, P = 0.006, respectively]. The presence of an aberrant anatomy and thickening of the gallbladder wall is an independent risk factor for the occurrence of bile duct injury.

Magnetic Resonance (MR) Cholangiopancreatography Demonstration of the Cystic Duct Entering the Right Hepatic Duct

Patient: Female, 51

Final Diagnosis: Cystic duct draining into the right hepatic biliary duct

Symptoms: Recurrent abdominal pain

Medication: —

Clinical Procedure: MR-cholangiopancreatography

Specialty: Radiology

Aberrant subvesical bile ducts identified during laparoscopic cholecystectomy: A rare case report and review of the literature

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Aberrant subvesical bile ducts are a rare anatomical variation defined as a network of bile ducts located in the peri-hepatic tissue of the gallbladder fossa.

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Their injury is almost inevitable and it leads to bile leakage, which is a life-threatening complication of laparoscopic cholecystectomy.

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Meticulous operative technique and detailed exposure of the operative field is the cornerstone of a safe laparoscopic cholecystectomy, when surgeons encounter this rare anatomical variation.

Introduction

Aberrant subvesical bile ducts are a scarce anatomical variation, consisted by a network of bile ducts located in the peri-hepatic capsule of the gallbladder fossa. These rare ducts are usually discovered intraoperatively and their presence poses the risk of bile injury and clinically significant bile leak.

Presentation of case

Aberrant subvesical bile ducts were unexpectedly identified in a young woman during laparoscopic cholecystectomy. These three ducts were clipped carefully for avoidance of bile duct injury and subsequent bile leak. The operation was uneventful. A meticulous review of the recent literature was conducted as well.

Discussion

This unusual anatomical variation of the biliary tract is mainly discovered during the operation. Thus, surgical injury of these ducts is nearly inevitable and it provokes the severe complication of bile leak. Bile injury represents the most crucial and life-threatening postoperative complication of cholecystectomies. Surgeons in the right upper quadrant of the abdomen should be constantly aware of this rare anatomical variation.

Conclusion

Aberrant subvesical bile ducts are associated with a high risk of surgical bile duct injury. Nevertheless, meticulous operative technique combined with surgeons’ perpetual awareness concerning this peculiar anatomical aberration leads to a safe laparoscopic cholecystectomy.

Common and Uncommon Anatomical Variants of Intrahepatic Bile Ducts in Magnetic Resonance Cholangiopancreatography and its Clinical Implication

Background

Preoperative knowledge of intrahepatic bile duct (IHD) anatomy is critical for planning liver resections, liver transplantations and complex biliary reconstructive surgery. The purpose of our study was to demonstrate the imaging features of various anatomical variants of IHD using magnetic resonance cholangio-pancreatography (MRCP) and their prevalence in our population.

Material/Methods

This observational clinical evaluation study included 224 patients who were referred for MRCP. MRCP was performed in a 1.5-Tesla magnet (Philips) with SSH MRCP 3DHR and SSHMRCP rad protocol. A senior radiologist assessed the biliary passage for anatomical variations.

Results

The branching pattern of the right hepatic duct (RHD) was typical in 55.3% of subjects. The most common variant was right posterior sectoral duct (RPSD) draining into the left hepatic duct (LHD) in 27.6% of subjects. Trifurcation pattern was noted in 9.3% of subjects. In 4% of subjects, RPSD was draining into the common hepatic duct (CHD) and in 0.8% of subjects into the cystic duct. Other variants were noted in 2.6% of subjects. In 4.9% of cases there was an accessory duct. The most common type of LHD branching pattern was a common trunk of segment 2 and 3 ducts joining the segment 4 duct in 67.8% of subjects. In 23.2% of subjects, segment 2 duct united with the common trunk of segment 3 and 4 and in 3.4% of subjects segment 2, 3, and 4 ducts united together to form LHD. Other uncommon branching patterns of LHD were seen in 4.9% of subjects.

Conclusions

Intrahepatic bile duct anatomy is complex with many common and uncommon variations. MRCP is a reliable non-invasive imaging method for demonstration of bile duct morphology, which is useful to plan complex surgeries and to prevent iatrogenic injuries.

Assessment and classification of cystic arteries with 64-detector row computed tomography before laparoscopic cholecystectomy

PURPOSE

Major complications of laparoscopic cholecystectomy are bleeding and bile duct injury, and it is necessary to clearly identify structures endoscopically to keep bleeding and injury from occurring. The aim of this study was to depict the anatomical variation between cystic arteries among patients using 64-detector row spiral computed tomography (CT) prior to laparoscopic cholecystectomy.

METHODS

A total of 78 patients (31 men, 47 women) who underwent cholecystectomy were examined preoperatively using 64-detector row spiral CT between April 2012 and June 2013. The origin and number of cystic arteries and their relationship with the Calot triangle was evaluated by two independent observers. CT images were compared with laparoscopic cholecystectomy results.

RESULTS

The cystic arteries were delineated by CT in 73 of the 78 patients. The relationship between the cystic arteries and the Calot triangle was identified in 71 of the 78 patients. One cystic artery was found in 53 (73%) of the 73 patients, while two cystic arteries were found in 20 (27%) of the patients. A total of 55 (60%) of the 91 cystic arteries passed through the Calot triangle. The remaining 36 cystic arteries (40%) passed anterior, posterior, or inferior to the cystic duct. The relationship between the cystic arteries and the Calot triangle detected by CT was in agreement with the surgical records for all patients.

CONCLUSION

The configuration of the cystic arteries and their relationship with the Calot triangle can be identified using 64-detector row CT before laparoscopic cholecystectomy.

Variations in biliary ductal and hepatic vascular anatomy and their relevance to the surgical management of choledochal cysts

PURPOSE

An aberrant biliary ductal and vascular anatomy presents a technical challenge for choledochal cyst (CDC) surgery. Mismanagement may have unfavourable implications. This study highlights the spectrum, approach to their identification and management.

METHODS

Forty of 117 (34 %) cases were identified to have an aberrant biliary ductal (n = 17) or arterial (n = 26) anatomy; 3 had both. The pancreaticobiliary anatomy was defined by an intraoperative cholangiogram (IOC) before January 2005 and a preoperative magnetic resonance cholangiopancreatogram (MRCP) subsequently.

RESULTS

IOC missed 3 of 4 aberrant biliary ducts, while an MRCP accurately delineated 10 of 13 aberrant bile ducts. The significant biliary anomalies were: an aberrant right sectoral/segmental duct joining the common hepatic duct (CHD) or the cyst itself (n = 14), cystic duct (n = 1) and cystic duct-CHD junction (n = 1). The aberrant duct was incorporated into the biliary-enteric anastomosis (B-EA) by: (i) double ostia B-EA (n = 1), (ii) ductoplasty with single ostium B-EA for aberrant duct and CHD (n = 2), and (iii) transection of the CHD/cyst distal to the aberrant duct orifice with a single ostium B-EA (n = 13). The arterial anomalies were (i) replaced or accessory right hepatic artery (RHA) (n = 11) and (ii) RHA crossing anterior to the cyst (n = 15), which was repositioned posterior to the B-EA.

CONCLUSION

It is important to consciously look for, appropriately identify and manage aberrant biliovascular anatomy. MRCP facilitates accurate preoperative delineation of aberrant duct anatomy. All major aberrant ducts need to be incorporated into the B-EA and aberrant arteries should not be ligated.

Micro-computed tomography and nuclear magnetic resonance imaging for noninvasive, live-mouse cholangiography

The cholangiopathies are a diverse group of biliary tract disorders, many of which lack effective treatment. Murine models are an important tool for studying their pathogenesis, but existing noninvasive methods for assessing biliary disease in vivo are not optimal. Here we report our experience with using micro-computed tomography (microCT) and nuclear magnetic resonance (MR) imaging to develop a technique for live-mouse cholangiography. Using mdr2 knockout (mdr2KO, a model for primary sclerosing cholangitis (PSC)), bile duct-ligated (BDL), and normal mice, we performed in vivo: (1) microCT on a Siemens Inveon PET/CT scanner and (2) MR on a Bruker Avance 16.4 T spectrometer, using Turbo Rapid Acquisition with Relaxation Enhancement, IntraGate Fast Low Angle Shot, and Half-Fourier Acquisition Single-shot Turbo Spin Echo methods. Anesthesia was with 1.5-2.5% isoflurane. Scans were performed with and without contrast agents (iodipamide meglumine (microCT), gadoxetate disodium (MR)). Dissection and liver histology were performed for validation. With microCT, only the gallbladder and extrahepatic bile ducts were visualized despite attempts to optimize timing, route, and dose of contrast. With MR, the gallbladder, extra-, and intrahepatic bile ducts were well-visualized in mdr2KO mice; the cholangiographic appearance was similar to that of PSC (eg, multifocal strictures) and could be improved with contrast administration. In BDL mice, MR revealed cholangiographically distinct progressive dilation of the biliary tree without ductal irregularity. In normal mice, MR allowed visualization of the gallbladder and extrahepatic ducts, but only marginal visualization of the diminutive intrahepatic ducts. One mouse died during microCT and MR imaging, respectively. Both microCT and MR scans could be obtained in ≤20 min. We, therefore, demonstrate that MR cholangiography can be a useful tool for longitudinal studies of the biliary tree in live mice, whereas microCT yields suboptimal duct visualization despite requiring contrast administration. These findings support further development and application of MR cholangiography to the study of mouse models of PSC and other cholangiopathies.

The Role of CT cholangiography in the Detection and Localisation of Suspected Bile Leakage Following Cholecystectomy

Background

Most bile duct injuries are not recognized at the time of initial surgery. Optimal treatment requires early recognition. CT IVC has become increasingly important in identifying bile leaks and their source after cholecystectomy. Our study aims to report the outcomes of using CT IVC post operatively and how accurately it can detect or localise bile leaks.

Methods

From 2000 - 2009, twenty patients were managed for suspected bile leak post cholecystectomy within the Alfred Hospital. The study included a retrospective evaluation of the initial procedure, presenting symptoms, site of ductal injury, diagnostic procedures and therapeutic interventions. Results were analysed to determine success of the imaging procedure, and to correlate imaging diagnosis with results both diagnostically and clinically.

Results

Twenty patients had a suspected bile leak, of which 3 were detected at the time of surgery. Seven patients had a CTIVC as their primary investigation. It identified bile leak in 6 and the anatomical site in 5. One had a leak excluded and was managed conservatively.

Conclusions

CT Cholangiography is a feasible and low-risk tool for imaging of the biliary tract in suspected bile leaks post cholecystectomy. It is a valuable non-invasive investigation that may help avoid endoscopic retrograde Cholangiography or surgery.

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.

ENBD tube placement prior to laparoscopic cholecystectomy may reduce the rate of complications in cases with predictably complicating biliary anomalies

BACKGROUND

The risk factors predisposing to bile duct injury or postoperative bile leakage associated with laparoscopic cholecystectomy (LC) include the presence of an accessory hepatic duct, the anomalous cystic duct confluence, and duct of Luschka. One method to prevent bile duct injury is preoperative placement of an endoscopic nasobiliary drainage tube (ENBD assisted LC). The aims of this investigation are first, to report the incidence of bile duct anomalies according to the classification system proposed by Wakayama Medical University and second, to evaluate the efficacy of ENBD assisted LC with regard to prevention of intraoperative bile duct injury and postoperative bile duct injury or leakage.

METHODS

A total of 1,835 consecutive LCs performed at our institution during a recent 10-year period were reviewed.

RESULTS

Anomalous cystic duct confluence was detected in 11 cases and an accessory hepatic duct was detected in 37 cases. These anomalies were risk factors for bile duct injury in our series. However, there was no significant difference in the length of surgery, conversion rate to laparotomy, or frequency of bile duct injury or leakage between the standard LC group and ENBD assisted LC group.

CONCLUSION

A bile duct anomaly was seen in 2.6% of LC cases. Placement of an ENBD tube prior to LC in predictably complicating bile duct anomalies may have successfully decreased the incidence of complications.

Right posterior branch draining into intra-pancreatic common duct: the triple duct sign

Simultaneous dilatation of pancreatic duct (PD) and common bile duct (CBD) is often seen on radio imaging in pancreatic head malignancy or chronic pancreatitis. This is called double duct sign. However, dilatation of aberrant bile duct along with PD and CBD resulting in triple duct sign on radio imaging has not been reported in literature till date. We report a case of 45 years old male with surgical jaundice due to pancreatic head mass. Computed tomography (CT) scan revealed three dilated ducts in the head of pancreas. Besides PD and biliary duct, the third duct was pre-operatively thought to be long cystic duct with low insertion in common hepatic duct (CHD). Intra-operative findings revealed an unusually long and dilated aberrant right posterior sectoral duct with low insertion into intra-pancreatic CHD. Patient underwent Whipple's procedure with two separate biliary anastomosis besides pancreaticojejunostomy. Histopathology of specimen revealed chronic pancreatitis. Retrospective analysis shows that Magnetic Resonance Cholangiopancreatogram (MRCP) should have been done for correct pre-operative delineation of this anatomical anomaly. In conclusion, pre-operative detection of triple duct dilatation on CT scan should be further investigated with MRCP for anatomical variations of the biliary tract. This can guide operative planning and prevent inadvertent biliary injuries.

Magnetic resonance imaging of gallbladder and biliary system

Gallbladder and biliary system pathologic component is a spectrum of benign and malignant conditions. Standard magnetic resonance imaging techniques when used together with magnetic resonance cholangiopancreatography (MRCP) can evaluate gallbladder and biliary system pathologic conditions. Inflammatory diseases are characterized by thickening and intense mucosal contrast enhancement of the affected bile ducts and or gallbladder wall. Postinflammatory changes can be appreciated on MRCP with short or long segment strictures of the bile ducts. Serial contrast-enhanced images show reactive inflammatory changes in the liver parenchyma. Neoplastic diseases of the gallbladder and the biliary tree are evaluated on T2-weighted fat-suppressed echo train and serial contrast-enhanced images and their obstructive effect can be displayed on MRCP images. In this paper, we will review the spectrum of MRI findings of gallbladder and biliary system pathologic conditions.

Biliary anatomy on 3D MRCP: Comparison of volume-rendering and maximum-intensity-projection algorithms

PURPOSE

To compare volume-rendering (VR) and maximum-intensity-projection (MIP) of three-dimensional T2-weighted turbo spin-echo magnetic resonance cholangiopancreatography using a free-breathing navigator-triggered prospective acquisition correction (3D-TSE-PACE-MRCP) to define biliary anatomies.

MATERIALS AND METHODS

VR and MIP images of 3D-TSE-PACE-MRCP for 102 patients were retrospectively evaluated. Interpretation of cystic duct variation and biliary branching patterns of each image were recorded independently by two radiologists in a blinded fashion. Interpretation confidence on a five-point scale was compared using the Wilcoxon signed-rank test. The McNemar test was used to compare the accuracies of each reformation with the reference standard obtained by consensus interpretation of both the images and source images.

RESULTS

The reference standard identified all biliary bifurcations and 95 of 102 cystic duct confluences (93.1%). VR findings agreed with the reference standard findings more often than MIP with regard to cystic duct variation (94 [92.2%] vs. 76 [74.5%], P<0.01) while there was no significant difference for biliary branching patterns (99 [97.1%] vs. 92 [90.2%], P=0.092). The mean confidence score was significantly higher with VR than MIP with regard to both cystic duct variation and biliary branching patterns (3.7 vs. 2.4; P<0.01; 4.1 vs. 3.3; P<0.01).

CONCLUSION

VR reformation of 3D-TSE-PACE-MRCP defines biliary anatomies more accurately than MIP.

Update on 3D and multiplanar MDCT in the assessment of biliary and pancreatic pathology

The development of multidetector row computed tomography (MDCT) has led to the acquisition of true isotropic voxels that can be postprocessed to yield images in any plane of the same resolution as the original axially acquired images. This, coupled with rapid MDCT imaging during peak target organ enhancement has led to a variety of means to review imaging information beyond that of the axial perspective. Postprocessing can be utilized to identify variant biliary anatomy to guide preoperative planning of biliary-related surgery, determine the level and cause of biliary obstruction and assist in staging of biliary cancer. Postprocessing can also be used to identify pancreatic ductal variants, visualize diagnostic features of pancreatic cystic lesions, diagnose and stage pancreatic cancer, and differentiate pancreatic from peripancreatic disease.

Computed tomography and magnetic resonance cholangiography

In patients with biliary obstruction, determining the level and the cause of the obstruction is essential because it can be a key factor for the next step in diagnostic or therapeutic intervention. Noninvasive cholangiography, such as computed tomography (CT) cholangiography or magnetic resonance (MR) cholangiography, allows the diagnosis of cause and level of biliary disease with minimal risk. Traditional magnetic resonance cholangiopancreatography (MRCP) is an established and effective noninvasive diagnostic modality particularly for extrahepatic biliary tract evaluation. Intrahepatic biliary duct evaluation and functional MR, including evaluating for leaks and gallbladder dyskinesia and outlet obstruction, are evolving diagnostic techniques that show promising results. CT cholangiography techniques are especially useful when MRI is not available or contraindicated or when the quality of MRCP images is suboptimal. CT cholangiography is particularly useful as an adjunct to surgery or postsurgical cases. The primary limitation of cholangiographic contrast-enhanced CT cholangiography (the most prevalent type of CT cholangiography) is its hindrance by poor liver function and/or high-grade biliary obstruction. In this setting MRCP is clearly superior. There are different types of CT cholangiography and MRCP. This article discusses the types of CT cholangiography and MRCP techniques and their clinical applications.

MR virtual endoscopy for biliary tract and pancreatic duct

Developments in magnetic resonance (MR) equipment and techniques have been remarkable. Especially, respiratory-triggered three-dimensional MR cholangiopancreatography (3D-MRCP) has been developed to provide images with high spatial resolution of the biliary tract and pancreatic duct. These 3D data can be employed in MR virtual endoscopy (MRVE) with volume rendering to visualize the lumina of the gallbladder, bile duct, and pancreatic duct. To observe the changes in the lumina with threshold settings on a workstation, we made an original phantom with tubes 2, 3, and 6 mm in internal diameter. We examined the changes in luminal diameter using several threshold settings by comparing the actual internal diameters to determine an appropriate threshold setting, which we then applied in 50 clinical cases, including pancreatic tumors, hepatic tumors, and biliary tract stones. We obtained MRVE images of the gallbladder, bile duct, and pancreatic duct to assess the clinical usefulness of this method. In the phantom study, a value identical to the actual luminal diameter could be obtained with a threshold of less than 20%. In all clinical cases, we obtained MRVE images of the gallbladder, bile duct, and pancreatic duct using the threshold we had determined appropriate and scored the diagnostic usefulness in each region. The MRVE images of the biliary tract provided much supplementary information, including the presence of stones and of duct invasion by the malignancy as wells as visualization of the post-stenotic portion. MRVE images of the gall bladder did not significantly improve diagnosis (P=0.311), but those of the bile and pancreatic ducts did (P<0.05). In addition, MRVE may aid navigation during cholangioscopy. Thus, MRVE is a clinically useful technique for examining lesions of the biliary tract and pancreas.

Vascular and biliary variants in the liver: implications for liver surgery

Accurate preoperative assessment of the hepatic vascular and biliary anatomy is essential to ensure safe and successful hepatic surgery. Such surgical procedures range from the more complex, like tumor resection and partial hepatectomy for living donor liver transplantation, to others performed more routinely, like laparoscopic cholecystectomy. Modern noninvasive diagnostic imaging techniques, such as multidetector computed tomography (CT) and magnetic resonance (MR) imaging performed with liver-specific contrast agents with biliary excretion, have replaced conventional angiography and endoscopic cholangiography for evaluation of the hepatic vascular and biliary anatomy. These techniques help determine the best hepatectomy plane and help identify patients in whom additional surgical steps will be required. Preoperative knowledge of hepatic vascular and biliary anatomic variants is mandatory for surgical planning and to help reduce postoperative complications. Multidetector CT and MR imaging, with the added value of image postprocessing, allow accurate identification of areas at risk for venous congestion or devascularization. This information may influence surgical planning with regard to the extent of hepatic resection or the need for vascular reconstruction.

3D anatomical variations of hepatic vasculature and bile duct for right lateral sector of liver with special reference to transplantation

To achieve a safer living related liver transplantation (LRLT) using the right lateral sector, anatomical variations of the portal vein, hepatic artery and bile duct for the right lateral sector and their three dimentional (3D) relationship were assessed by integrated 3D-CT images. 52 patients who underwent contrast enhanced multi-detector row CT (MD-CT) and MD-CT cholangiography were enrolled. Data from contrast enhanced MD-CT were used to reconstruct the 3D images of the hepatic artery and portal vein. 3D images reconstructed from MD-CT data of the hepatic artery, portal vein and bile duct were integrated into a single image. The dual branching of the right lateral portal vein was observed in 22 (42.3%) patients. Three (5.8%) had dual right lateral ducts and 14 (26.9%) had dual right lateral arteries. Among them, "south-turning" artery and "north-turning" bile duct was observed in 22 (42.3%). "South-turning" artery and "south-turning" bile duct were 3 (5.8%). "North-turning" artery and "north-turning" bile duct were 2 (7.4%). Only 27 (51.9%) had single portal vein, bile duct and artery for the right lateral sector, those were preferable as candidates for right lateral sector graft transplantation. 3D anatomical variations of portal vein, artery and bile duct for the right lateral sector were complexed, and only half of the donor candidates had preferable hepatic structures for right lateral sector graft transplantation. Understanding of the 3D hepatic structures by 3D-CT may contribute to a better definition of anatomical contraindications for LRLT which may further results in more safe and widely applied right lateral sector graft LRLT.

On the mechanical behavior of the human biliary system

This paper reviews the progress made in understanding the mechanical behaviour of the biliary system. Gallstones and diseases of the biliary tract affect more than 10% of the adult population. The complications of gallstones, i.e. acute pancreatitis and obstructive jandice, can be lethal, and patients with acalculous gallbladder pain often pose diagnostic difficulties and undergo repeated ultrasound scans and oral cholecystograms. Moreover, surgery to remove the gallbladder in these patients, in an attempt to relieve the symptoms, gives variable results. Extensive research has been carried out to understand the physiological and pathological functions of the biliary system, but the mechanism of the pathogenesis of gallstones and pain production still remain poorly understood. It is believed that the mechanical factors play an essential role in the mechanisms of the gallstone formation and biliary diseases. However, despite the extensive literature in clinical studies, only limited work has been carried out to study the biliary system from the mechanical point of view. In this paper, we discuss the state of art knowledge of the fluid dynamics of bile flow in the biliary tract, the solid mechanics of the gallbladder and bile ducts, recent mathematical and numerical modelling of the system, and finally the future challenges in the area.

Preoperative endoscopic sphincterotomy versus laparoendoscopic rendezvous in patients with gallbladder and bile duct stones

OBJECTIVE

To compare success rate, length of hospital stay, clinical results, and costs of sequential treatment (endoscopic retrograde cholangiopancreatography followed by laparoscopic cholecystectomy) versus the laparoendoscopic Rendezvous in patients with cholecysto-choledocholithiasis.

BACKGROUND

The ideal management of common bile duct (CBD) stones in the era of laparoscopic cholecystectomy (LC) remains controversial.

METHODS

A total of 91 elective patients with cholelithiasis and CBD stones diagnosed at magnetic resonance cholangiography (MRC) were included in a prospective, randomized trial. The patients were randomized in 2 groups. Group I patients (45 cases) underwent a preoperative endoscopic retrograde cholangiopancreatography (ERCP) with endoscopic sphincterotomy (ES) followed by LC in the same hospital admission. Group II patients (46 cases) underwent LC associated with intraoperative ERCP and ES according to the rendezvous technique.

RESULTS

The rate of CBD clearance was 80% for Group I and 95.6% for Group II (P = 0.06). The morbidity rate was 8.8% in Group I and 6.5% in Group II (P = not significant). No deaths occurred in either group. Hospital stay was shorter in Group II than in Group I: 4.3 days versus 8.0 days (P < 0.0001). There was a significant reduction in mean total cost for group II patients versus group I patients: 2829 euro versus 3834 euro (P < 0.05).

CONCLUSIONS

When compared with preoperative ERCP with ES followed by LC, the laparoendoscopic rendezvous technique allows a higher rate of CBD stones clearance, a shorter hospital stay, and a reduction in costs.

High-Resolution Computed Tomographic Angiography/Computed Tomographic Cholangiography Image Fusion of the Hepatobiliary System

The 3-dimensional image was excellent as a result of the fast scanning and narrow collimation using multidetector computed tomography (CT); and the parallel escalation in the capabilities of the workstation allow the use of CT angiography/CT cholangiography image fusion. We demonstrated the feasibility of fusion images of the hepatobiliary system. We believe that fusion images are extremely valuable for applications such as preoperative planning for hepatic and bile duct resection.

Multimodality imaging of pancreatic and biliary congenital anomalies

A wide spectrum of anomalies of the pancreas, the pancreatic ductal system, and the biliary tree are commonly encountered at radiologic evaluation. These anomalies may simulate various neoplastic, inflammatory, and posttraumatic conditions and should be part of the differential diagnosis for a variety of abnormalities found at diagnostic imaging. Anatomic variants, developmental anomalies (eg, pancreas divisum, annular pancreas, ectopic pancreas, pancreatic agenesis and hypoplasia), and congenital diseases (congenital pancreatic cysts, von Hippel-Lindau disease, choledochal cysts), in addition to potential imaging pitfalls (uneven distribution of fat, "pseudomasses"), can all pose a diagnostic challenge for the radiologist. Familiarity with these anomalies, the imaging techniques available for their study, and their variable imaging manifestations is necessary for differentiating them from other biliary and pancreatic conditions. A basic understanding of the embryologic development and normal anatomy of the pancreas and biliary tree is also essential for identifying these anomalies.

Preoperative evaluation of the extrahepatic bile duct structure for laparoscopic cholecystectomy

BACKGROUND

The incidence of aberrant bile duct injury associated with laparoscopic cholecystectomy (LC) has not yet been adequately examined. This study aimed to clarify the types of normal cystic ducts and the incidence of aberrant extrahepatic bile ducts, and to search for a method of avoiding injuries during LC.

METHODS

Aberrant hepatic ducts were retrospectively categorized into five types according to the pattern of the cystic ducts and the accessory hepatic ducts by preoperative endoscopic retrograde cholangiography or multidetector three-dimensional computed tomography using drip infusion cholangiography. The aberrant bile ducts were classified as type A (merging at the right side of the common bile duct), type B (merging at the anterior side), or type C (merging at the posterior left side).

RESULTS

The intrahepatic bile ducts and cystic duct were clearly shown for 1,044 of the 1,278 patients who underwent LC. Secondary branches of aberrant cystic ducts were observed in 37 cases (3.5%), and accessory hepatic ducts were observed in 30 cases (2.9%). A comparison of the difficulties encountered with LC for each type based on the merging patterns of cystic ducts showed that type C needed a much longer operation time for LC than the other types.

CONCLUSIONS

A preoperative evaluation of the bile duct tract and the accessory hepatic duct before LC is important. Patients with a cystic duct merging normally into the posterior left side of the common hepatic duct (type C) experienced difficulty when undergoing LC. The authors have safely performed LC with the use of an endoscopic nasobiliary drainage tube in type D cases (cystic duct merging with the right hepatic duct), in type IV cases (cystic duct merging with an accessory hepatic duct).

Three-dimensional drip infusion CT cholangiography in patients with suspected obstructive biliary disease: a retrospective analysis of feasibility and adverse reaction to contrast material

Background

Computed Tomography Cholangiography (CTC) is a fast and widely available alternative technique to visualise hepatobiliary disease in patients with an inconclusive ultrasound when MRI cannot be performed. The method has previously been relatively unknown and sparsely used, due to concerns about adverse reactions and about image quality in patients with impaired hepatic function and thus reduced contrast excretion. In this retrospective study, the feasibility and the frequency of adverse reactions of CTC when using a drip infusion scheme based on bilirubin levels were evaluated.

Methods

The medical records of patients who had undergone upper abdominal spiral CT with subsequent three-dimensional rendering of the biliary tract by means of CTC during seven years were retrospectively reviewed regarding serum bilirubin concentration, adverse reaction and presence of visible contrast media in the bile ducts at CT examination. In total, 153 consecutive examinations in 142 patients were reviewed.

Results

Contrast media was observed in the bile ducts at 144 examinations. In 110 examinations, the infusion time had been recorded in the medical records. Among these, 42 examinations had an elevated bilirubin value (>19 umol/L). There were nine patients without contrast excretion; 3 of which had a normal bilirubin value and 6 had an elevated value (25–133 umol/L). Two of the 153 examinations were inconclusive. One subject (0.7%) experienced a minor adverse reaction – a pricking sensation in the face. No other adverse effects were noted.

Conclusion

We conclude that drip infusion CTC with an infusion rate of the biliary contrast agent iotroxate governed by the serum bilirubin value is a feasible and safe alternative to MRC in patients with and without impaired biliary excretion.

In this retrospective study the feasibility and the frequency of adverse reactions when using a drip infusion scheme based on bilirubin levels has been evaluated.

3.0- Versus 1.5-T MR Cholangiography: A Pilot Study

OBJECTIVE

The purpose of our study was to evaluate quantitative and qualitative image quality of MR cholangiography at a field strength of 3.0 T compared with the standard field strength of 1.5 T.

MATERIALS AND METHODS

A standardized MR cholangiography sequence protocol was used for 15 healthy male volunteers (mean age +/- SD, 32.4 +/- 4.3 years) who underwent both 1.5- and 3.0-T MRI within 2 hr in an alternating fashion. Dedicated circular polarized torso coils (1.5 and 3.0 T) were used. The sequence protocol included breath-hold single-slice rapid acquisition with relaxation enhancement (slice thickness, 50 mm; orientation, coronal and +/- 20 degrees oblique coronal); breath-hold multislice HASTE (slice thickness, 3 mm; coronal only); and a non-breath-hold, respiratory-triggered 3D turbo spin-echo (TSE) T2-weighted sequence (slice thickness, 1 mm; 60 slices per slab; coronal only). Maximum intensity projections were generated from each multislice data set. Bile duct (common bile duct, right posterior segmental branch, and left hepatic duct) to periductal tissue contrast-to-noise ratios were compared at 1.5 and 3.0 T. Qualitative image analysis was performed by three independent reviewers. Qualitative analysis included delineation of the extra- and intrahepatic biliary anatomy, with specific attention given to the presence (or absence) of cystic or intrahepatic ductal variants, using a 4-point confidence scale. Statistical analysis consisted of the paired Student's t test and the signed rank test.

RESULTS

Contrast-to-noise ratios between the bile duct and the periductal tissue were higher at 3.0 T in all three locations (common bile duct, right posterior segmental branch, and left hepatic duct). In each magnet class, the 3D TSE sequence offered the best contrast-to-noise ratio and qualitative analysis. Superiority of the 3D TSE sequence was statistically significant in all analyses. Five of the 15 volunteers had intrahepatic biliary variants that were detected with a higher level of confidence (p < 0.01) on the 3.0-T system than on the 1.5-T system.

CONCLUSION

Compared with MR cholangiography at 1.5 T, MR cholangiography at 3.0 T offers improved contrast-to-noise ratio and a higher level of confidence for depicting intrahepatic variants.

Cystic duct and Heister's "valves"

The anatomy and physiology of the cystic duct have been relatively neglected by anatomists and the function of the spiral mucosal folds or "valves" of Heister, first described in 1732, remains obscure. The gross and microscopic anatomy of the cystic duct is reviewed together with results from laboratory investigations into the function of the cystic duct and its spirally arranged folds. The duct and spiral folds contain muscle fibers responsive to pharmacologic, hormonal, and neural stimuli. There is, however, no convincing evidence of a discrete muscular sphincter within the duct. Although the cystic duct is unlikely to play a major role in gallbladder filling and emptying, it appears to function as more than a passive conduit. Coordinated, graded muscular activity in the cystic duct in response to hormonal and neural stimuli may facilitate gallbladder emptying. The principal function of the internal spiral folds that are found in man and other animals may be to preserve patency of this narrow, tortuous tube rather than to regulate bile flow.

Compression of the common hepatic duct by the right hepatic artery

Magnetic resonance (MR) cholangiography has been used wildly as preoperative examination before laparoscopic cholecystectomy (LSC). However, cases that suggested the stenotic lesion of extrahepatic bile duct are not so rare in MR cholangiography. When stenosis is found, further examination is needed to avoid the possibility of bile duct cancer. We reported a case in which the stenotic lesion was diagnosed compression of the common hepatic duct by the right hepatic artery by multislice CT (MCT) cholangiography.