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.

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 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.

Effectiveness of near-infrared fluorescent cholangiography in the identification of cystic duct-common hepatic duct anatomy in comparison to magnetic resonance cholangio-pancreatography: a preliminary study.

INTRODUCTION: Bile duct injury represents the most serious complication of LC, with an incidence of 0.3-0.7% resulting in a significant impact on quality-of-life, overall survival, and frequent medico-legal litigations. Near-infrared fluorescent cholangiography (NIRF-C) represents a novel intra-operative imaging technique that allows a real-time enhanced visualization of the extrahepatic biliary tree by fluorescence. The role of routine use of pre-operative magnetic resonance cholangio-pancreatography (MRCP) to better clarify the biliary anatomy before laparoscopic cholecystectomy is still a matter of debate. The primary aim of this study was to evaluate the effectiveness of NIRF-C in the detection of cystic duct-common hepatic duct anatomy intra-operatively in comparison with pre-operative MRCP. METHODS: Data from 26 consecutive patients with symptomatic cholelithiasis or chronic cholecystitis, who underwent elective laparoscopic cholecystectomy with intra-operative fluorescent cholangiography and pre-operative MRCP examination between January 2018 and May 2018, were analyzed. Three selected features of the cystic duct-common hepatic duct anatomy were identified and analyzed by the two different imaging methods: insertion of cystic duct, cystic duct-common hepatic duct junction, and cystic duct course. RESULTS: Fluorescent cholangiography was performed successfully in all twenty-six patients undergoing elective laparoscopic cholecystectomy. The visualization of cystic duct was reported in 23 out of 26 cases, showing an overall diagnostic accuracy of 86.9%. The level of insertion, course, and wall implantation of cystic duct were achieved by NIRF-C with diagnostic accuracy values of 65.2%, 78.3%, and 91.3%, respectively in comparison with MRCP data. No bile duct injuries were reported. CONCLUSION: Fluorescent cholangiography can be considered a useful imaging diagnostic tool comparable to MRCP for detailed intra-operative visualization of the cystic duct-common hepatic duct anatomy during elective laparoscopic cholecystectomies.

Clinical investigation of the cystic duct variation based on the anatomy of the hepatic vasculature.

PURPOSE: Anatomical variation of the cystic duct (CD) is rare but can result in misunderstanding of the CD anatomy during laparoscopic cholecystectomy, potentially leading to bile duct injury. Therefore, the precise preoperative identification of CD variation is important. However, preoperative imaging analyses of the biliary system are not always possible or sufficient. We therefore investigated CD variations based on the anatomy of the hepatic vasculature. METHODS: This study enrolled 480 patients who underwent imaging before hepatobiliary pancreatic surgery. We assessed the variation of the CD and hepatic vasculature and evaluated the correlations among these variations. RESULTS: A variant CD anatomy was identified in 12 cases (2.5%) as CD draining into the right hepatic bile duct (BD) in 4 cases and into the right posterior BD in 8 cases. CD variation was significantly more common in cases with portal vein (PV) and BD variation than in those without the variation. We developed a scoring system based on the presence of PV and BD variations that showed good discriminatory power for identification of CD variants. CONCLUSION: Cases with a variant CD anatomy were more likely to exhibit variant PV and BD anatomies than cases with a normal CD anatomy. These findings will be useful for the preoperative identification of CD variants.

Classification of the cystic duct patterns and endoscopic transpapillary cannulation of the gallbladder to prevent post-ERCP cholecystitis.

BACKGROUND: Endoscopic transpapillary cannulation of the gallbladder is useful but challenging. This study aimed to investigate cystic duct anatomy patterns, which may guide cystic duct cannulation. METHODS: A total of 226 patients who underwent endoscopic transpapillary cannulation of the gallbladder were analyzed retrospectively. RESULTS: According to the cystic duct take-off, 226 cystic duct patterns were divided into 3 patterns: Type I (193, 85.4%), located on the right and angled up; Type II (7, 3.1%), located on the right and angled down; and Type III (26, 11.5%), located on the left and angled up. Type I was further divided into three subtypes: Line type, S type (S1, not surrounding the common bile duct; S2, surrounding the common bile duct), and α type (α1, forward α; α2, reverse α). Types I and III cystic ducts were easier to be cannulated with a higher success rate (85.1 and 86.4%, respectively) compared with Type II cystic duct (75%) despite no statistically significant difference. The reasons for the failure of gallbladder cannulation included invisible cyst duct take-off, severe cyst duct stenosis, impacted stones in cyst duct or neck of the gallbladder, sharply angled cyst duct, and markedly dilated cyst duct with the tortuous valves of Heister. CONCLUSION: Classification of cystic duct patterns was helpful in guiding endoscopic transpapillary gallbladder cannulation.

Surgeons see anatomical structures faster and more accurately compared to novices: Development of a pattern recognition skill assessment platform.

BACKGROUND: This study aimed to identify differences in pattern recognition skill among individuals with varying surgical experience. METHODS: Participants reviewed laparoscopic cholecystectomy videos of various difficulty, and paused them when the cystic duct or artery was identified to outline each structure on the monitor. Time taken to identify each structure, accuracy and work load, which was assessed using the NASA-Task Load Index (TLX), were compared among the three groups. RESULTS: Ten students, ten residents and eight attendings participated in the study. Attendings identified the cystic duct and artery significantly faster and more accurately than students, and identified the cystic artery faster than residents. The NASA-TLX score of attendings was significantly lower than that of students and residents. CONCLUSIONS: Attendings identified anatomical structures faster, more accurately, and with less effort than students or residents. This platform may be valuable for the assessment and teaching of pattern recognition skill to novice surgeons. SHORT SUMMARY: Accurate anatomical recognition is paramount to proceeding safely in surgery. The assessment platform used in this study differentiated recognition skill among individuals with varing surgical experience.

Biliary tract in trident, an anatomical variation between the cystic duct and its union to the common hepatic duct: a rare case report / Tracto biliar en tridente, una variación anatómica entre el conducto cístico y su unión al conducto hepático común: un caso raro

SUMMARY: Given that the gallbladder and the biliary tract are subject to multiple anatomical variants, detailed knowledge of embryology and its anatomical variants is essential for the recognition of the surgical field when the gallbladder is removed laparoscopically or by laparotomy, even when radiology procedures are performed. During a necropsy procedure, when performing the dissection of the bile duct is a rare anatomical variant of the bile duct, in this case the cystic duct joins at the confluence of the right and left hepatic ducts giving an appearance of trident. This rare anatomical variant in the formation of common bile duct is found during the exploration of the bile duct during a necropsy procedure, it is clear that the wrong ligation of a common hepatic duct can cause a great morbi-mortality in the postsurgical of biliary surgery. This rare anatomical variant not previously described is put in consideration to the scientific community. Anatomical variants of the biliary tract are associated with high rates of morbidity and mortality, causing serious bile duct injuries. Only the surgical skill of the surgeon and his open mind to the possibilities of abnormalities make the performance of cholecystectomy a safe procedure.

RESUMEN: Dado que la vesícula biliar y el tracto biliar están sujetos a múltiples variantes anatómicas, el conocimiento detallado de la embriología y sus variantes anatómicas es esencial para el reconocimiento del campo quirúrgico cuando la vesícula biliar se extirpa laparoscópicamente o por laparotomía, incluso cuando se realizan procedimientos de radiología. Durante un procedimiento de necropsia, se realiza la disección del conducto biliar y se observa una variante anatómica inusual del conducto biliar; en este caso, el conducto cístico se une a la confluencia de los conductos hepáticos derecho e izquierdo dando una apariencia de tridente. Esta rara variante anatómica en la formación del conducto biliar común puede causar una gran morbimortalidad en la cirugía biliar asociado a una ligadura incorrecta. Esta extraña variante anatómica no descrita anteriormente se reporta a la comunidad científica, debido a que las variantes anatómicas del tracto biliar se asocian con altas tasas de morbilidad y mortalidad, al causar lesiones graves en el conducto biliar. Solo la habilidad quirúrgica del cirujano y su mente abierta a las posibilidades de variaciones anatómicas hacen que la realización de la colecistectomía sea un procedimiento seguro.

Trígono cistohepático: área crítica anatómica para la seguridad quirúrgica / Trigonum cystohepaticum: critical anatomical area for surgical safety

El conocimiento de la anatomía de la vía biliar y sus variantes para la realización de una cirugía segura, resulta fundamental. La extirpación de la vesícula requiere cuidadosa atención, conocer muy bien la anatomía de la región, teniendo en cuenta la posibilidad de variaciones anatómicas. La mala interpretación de la anatomía percibida más que una falta en la destreza técnica es la causa de la lesión de la vía biliar durante la colecistectomía. Diferenciar el límite y el contenido del trígono cistohepático. Diseñar las áreas de Visión Crítica y de Seguridad como medida de seguridad en el paciente quirúrgico. Revisión de 458 partes quirúrgicos de colecistectomías de enero/2010 a octubre/2012, en el Servicio de Cirugía General del Hospital Aeronáutico Central, y disección de 12 cadáveres adultos formolizados al 10% en la III Cátedra de Anatomía - Facultad de Medicina - Universidad de Buenos Aires. De 458 colecistectomías, se clasificaron los partes quirúrgicos, dividiéndose según menciona: triángulo de Calot en 247 (53,93%); triángulo hepatocístico en 59 (12,88%); área de visión crítica en 152 (33,18%); ninguno mencionó al triángulo de Budde o trígono cistohepático. Se disecaron 12 cadáveres adultos donde se identificó: arteria cística originándose de arteria hepática derecha en 9 (75%); originándose de arteria hepática izquierda en 2 (16,66%) y originándose de arteria hepática en 1 (8,34%). En 7 (58,35%) se la visualiza en trígono cistohepático. El conocimiento de la anatomía de la vía biliar y sus variantes para la realización de una cirugía segura, resulta fundamental. El triángulo descrito por Calot corresponde a la mitad inferior del triángulo descrito por Buddé. El sector lateral (Triangulo de Seguridad) es el verdadero área de visión critica a disecar por la menor probabilidad de lesionar estructuras nobles.

Knowing the anatomy of the bile duct and its anatomical variations becomes essential to safely perform any surgery. Gallbladder resection requires careful attention: knowing the region's anatomy by heart and taking into account the possibility of anatomical variations. Misunderstanding the anatomy is not only a failure in technical ability but also a cause of injury to the bile duct during a cholescystectomy. The objectives of this study were, to distinguish the boundaries and content of the trigonum cystohepaticum. Furthermore, to design the areas of Safety and Critical Vision as a safety measure for the patient undergoing surgery. Analysis of 458 surgical reports on cholecystectomies performed from January 2010 to October 2012 by the Hospital Aeronáutico's General Surgery Department, and dissection of 12 adult cadavers preserved in a 10% formalin solution at the IIIrd Chair of Anatomy, School of Medicine, University of Buenos Aires. From 458 cholecystectomies, surgical reports were classified as mentioning: Calot triangle, 247 (53.93%); cystohepatic triangle, 59 (12.88%); critical vision area, 152 (33.18%). None of them mentioned Buddé triangle or trigonum cystohepaticum. Twelve adult cadavers were dissected in which we identified the cystic artery: originating from right hepatic artery, 9 (75%); originating from left hepatic artery, 2 (16.66%); and originating from hepatic artery, 1 (8.34%). Trigonum cystohepaticum is observed in 7 cadavers (58.35%). Knowing the anatomy of the bile duct and its anatomical variations becomes essential to safely perform any surgery. The triangle described by Calot is the lower half of the triangle described by Buddé. The lateral portion (Safety Triangle) is the area of critical vision to be dissected due to the lower probability of injuring noble structures.

The cystohepatic septum: anatomical findings and surgical considerations.

INTRODUCTION: The cystohepatic septum (CHS) is located at the interface between the cystic duct and the common hepatic duct. Although its presence may have clinical and surgical implications, the CHS has never been morphologically studied. AIM: This study aims to determine the prevalence and anatomic characteristics of the cystohepatic septum. METHODS: Analytical cross-sectional study of 50 cadaveric dissections was performed. The prevalence and anatomic characteristics of the CHS were analyzed. The cystohepatic junction (CHJ) was characterized from two perspectives. The "external CHJ" was defined as the apparent junction of the cystic duct with the common hepatic duct, as viewed from an extraluminal perspective. The "internal CHJ" was defined as the actual junction of the cystic duct lumen with the common hepatic duct lumen, that is, from the intraluminal perspective. In addition to measuring the length of the CHS, the location of the external and internal CHJ along the length of the extrahepatic biliary tract was classified into three zones (proximal, middle, and distal). RESULTS: A CHS was identified in 21 cases (42%). The average length was 12 mm. In these 21 cases, the external CHJ was located in the middle zone of the extrahepatic biliary tract in 15 (71%) patients, the proximal zone in 3 (14%), and the distal zone in 3 (14%), while the internal CHJ was located downstream in relation to the length of CHS. CONCLUSIONS: A CHS of variable length was identified in a large percentage of cadaveric dissections. This finding has important implications for surgical interventions on the biliary tract such as choledochotomy for common bile duct exploration, transcystic bile duct exploration, or bilioenteric anastomosis. The presence of a CHS may also represent an anatomic factor predisposing to Mirizzi's syndrome.

Near-infrared fluorescence laparoscopy of the cystic duct and artery in pigs: performance of a preclinical dye.

BACKGROUND: Near-infrared fluorescence laparoscopy after intravenous indocyanine green (ICG) administration has been proposed as a promising surgical imaging technique for real-time visualization of the extrahepatic bile ducts and arteries in clinical laparoscopic cholecystectomies. However, optimization of this new technique with respect to the imaging system combined with the fluorophore is desirable. The performance of a preclinical near-infrared dye, CW800-CA, was compared with that of ICG for near-infrared fluorescence laparoscopy of the cystic duct and artery in pigs. MATERIALS AND METHODS: Laparoscopic cholecystectomy was performed in six pigs (average weight, 35 kg) using a commercially available laparoscopic fluorescence imaging system. The fluorophores CW800-CA and ICG (both 800 nm fluorescent dyes) were administered by intravenous injection in four and two pigs, respectively. CW800-CA was administered in three different doses (consecutively 0.25, 1, and 3 mg); ICG was intravenously injected (2.5 mg) for comparison. Intraoperative recognition of the biliary structures was recorded at set time points. The target-to-background ratio was determined to quantify the fluorescence signal of the designated tissues. RESULTS: A clinically proven dose of 2.5 mg of ICG resulted in a successful fluorescence delineation of both the cystic duct and artery. In the CW800-CA-injected pigs a clear visualization of the cystic duct and artery was obtained after administration of 3 mg of CW800-CA. Time from injection until fluorescence identification of the cystic duct was reduced when CW800-CA was used compared with ICG (11.5 minutes versus 21.5 minutes, respectively). CW800-CA provided clearer illumination of the cystic artery, in terms of target-to-background ratio. CONCLUSIONS: As well as ICG, CW800-CA can be applied for fluorescence identification of the cystic artery and duct using a commercially available laparoscopic fluorescence imaging system. Fluorescence cholangiography of the cystic duct can be obtained earlier after intravenous injection of CW800-CA, compared with ICG. These findings increase the possibilities of use and of optimization of this imaging technique.

Direct puncture cholangiography for clarifying difficult anatomy.

Laparoscopic cholecystectomy is a very frequently performed procedure. Its most dreadful complication is bile duct injury. Difficulty in appreciating the biliary anatomy plays an important role in its causation. Here we describe our technique in clarifying the difficult anatomy by directly injecting the radiologic contrast in the ambiguous area, and thus avoiding a potential injury.

Calot's triangle.

Calot's triangle is an anatomical landmark of special value in cholecystectomy. First described by Jean-François Calot as an "isosceles" triangle in his doctoral thesis in 1891, this anatomical space requires careful dissection before the ligation and division of the cystic artery and cystic duct during cholecystectomy. The modern definition of the boundaries of Calot's triangle varies from Calot's original description, although the exact timing of this change is not entirely clear. The structures within Calot's triangle and their anatomical relationships can present the surgeon with difficulties, particularly when anatomical variations are encountered. Sound knowledge of the normal anatomy of the extrahepatic biliary tract and vasculature, as well as understanding of congenital variation, is thus essential in the prevention of iatrogenic injury. The authors describe the normal anatomy of Calot's triangle and common anatomical anomalies. The incidence of structural injury is discussed, and new techniques in surgery for enhancing the visualisation of Calot's triangle are reviewed. © .

Documenting correct assessment of biliary anatomy during laparoscopic cholecystectomy.

BACKGROUND: Correct assessment of biliary anatomy can be documented by photographs showing the "critical view of safety" (CVS) but also by intraoperative cholangiography (IOC). METHODS: Photographs of the CVS and IOC images for 63 patients were presented to three expert observers in a random and blinded fashion. The observers answered questions pertaining to whether the biliary anatomy had been conclusively documented. RESULTS: The CVS photographs were judged to be "conclusive" in 27%, "probable" in 35%, and "inconclusive" in 38% of the cases. The IOC images performed better and were judged to be "conclusive" in 57%, "probable" in 25%, and "inconclusive" in 18% of the cases (P < 0.001 compared with the photographs). The observers indicated that they would feel comfortable transecting the cystic duct based on the CVS photographs in 52% of the cases and based on the IOC images in 73% of the cases (P = 0.004). The interobserver agreement was moderate for both methods (kappa values, 0.4-0.5). For patients with a history of cholecystitis, both the CVS photographs and the IOC images were less frequently judged to be sufficient for transection of the cystic duct (P = 0.006 and 0.017, respectively). CONCLUSION: In this series, IOC was superior to photographs of the CVS for documentation of the biliary anatomy during laparoscopic cholecystectomy. However, both methods were judged to be conclusive only for a limited proportion of patients, especially in the case of cholecystitis. This study highlights that documenting assessment of the biliary anatomy is not as straightforward as it seems and that protocols are necessary, especially if the images may be used for medicolegal purposes. Documentation of the biliary anatomy should be addressed during training courses for laparoscopic surgery.

Unique origin of the cystic artery.

The cystic artery (CA) is known to exhibit variations in its origin and branching pattern. This is attributed to the developmental changes occurring in the primitive ventral splanchnic arteries. During routine dissection of a male cadaver, we observed that the CA originated from the middle hepatic artery (MHA) at a distance of about 1 cm from its origin, and the MHA originated from the right hepatic artery at a distance of 2.1 cm from its origin. The CA traversed for a distance of 1.5 cm, giving off a branch to the cystic duct. It then passed anterior to the cystic duct. The origin of the CA was located to the left of the common hepatic duct, outside the Calot's triangle. The topographical anatomy of the arterial system of the hepatobiliary region and their anomalous origin should be considered during hepatobiliary surgeries. This knowledge is also important for interventional radiologists in routine clinical practice.

Raising the thinker: new concept for dissecting the cystic pedicle during laparoscopic cholecystectomy.

Imprecise dissection due to poor visualization of anatomic structures is among the major causes of biliary injuries during laparoscopic cholecystectomy. Developing new illustrational and rendering techniques represents an important part in decreasing visual deception and subsequent bile duct injuries. We use the model of one of the most well-known pieces of art, Rodin's The Thinker, to visualize the gallbladder and cystic pedicle structures. This minimizes visual deception before dissection, especially in cases with obscured structures. Our method, raising The Thinker, is based on the remarkable similarity between the sculpture and the topographic anatomy of the gallbladder. The method can be used not only for better orientation and visualization during laparoscopic cholecystectomy but also as a tool to complement the teaching of laparoscopic biliary anatomy to surgical residents and medical students.

Multimedia article. The fear of transgastric cholecystectomy: misinterpretation of the biliary anatomy.

INTRODUCTION: Prevention of injury during cholecystectomy relies on accurate dissection of the cystic duct and artery and avoidance of major biliary and vascular structures. The advent of natural orifice translumenal surgery (NOTES) has led to a new look into the biliary anatomy, especially Calot's triangle. Here we show the clinical case of a NOTES transgastric cholecystectomy for uncomplicated cholelithiasis, in which misinterpretation of the biliary anatomy occurred. METHODS AND PROCEDURE: A 5-mm port was introduced at the umbilicus to ascertain the feasibility of transgastric cholecystectomy and to ensure safe gastrotomy creation and closure. Transgastric access was obtained using a percutaneous endoscopic gastrostomy (PEG)-like technique on the anterior mid body of the stomach to pass a 12-mm gastroscope (Karl Storz, Tuttlingen, Germany). The laparoscope was switched to a grasper for gallbladder retraction. Dissection was started close to the gallbladder using the endoscope at the junction between the infundibulum and what was thought to be the cystic duct. During dissection, the size and the orientation of the cystic duct appeared to be unclear. The decision was made to switch to a laparoscopic view to reorient the dissection plane and clarify the anatomy. At laparoscopy, dissection of the triangle of Calot, although started close to the gallbladder, appeared far too low. The common bile duct had been mistaken for the cystic duct. Once the biliary anatomy was clarified, the vision was switched back to the endoscope, but an additional 2-mm grasper was introduced to improve exposure while cholecystectomy was performed in a standard fashion. CONCLUSIONS: Specific anatomic distortions due to NOTES technique together with the lack of exposure provided by current methods of retraction tend to distort Calot's triangle by flattening it rather than opening it out. At this stage, whenever the anatomy of the biliary tract is unclear, a temporary "conversion" to a laparoscopic view, more familiar to the surgeon's eye, is recommended.

Right anterior segmental hepatic duct emptying directly into the cystic duct in a living donor.

A 35-year-old mother was scheduled to be the living donor for liver transplantation to her second son, who suffered from biliary atresia complicated with biliary cirrhosis at the age of 2 years. The operative plan was to recover the left lateral segment of the mother's liver for living donor transplantation. With the use of cholangiography at the time of surgery, we found the right anterior segmental duct (RASD) emptying directly into the cystic duct, and the catheter passed into the RASD. After repairing the incision in the cystic duct, transplantation was successfully performed. Her postoperative course was uneventful. Biliary anatomical variations were frequently encountered, however, this variation has very rarely been reported. If the RASD was divided, the repair would be very difficult because the duct will not dilate sufficiently in an otherwise healthy donor. Meticulous preoperative evaluation of the living donor's biliary anatomy, especially using magnetic resonance cholangiography and careful intraoperative techniques, is important to prevent bile duct injury and avoid the risk to the healthy donor.