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.

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. © .

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.

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.

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.

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.

The course of the cystic artery during laparoscopic cholecystectomy.

Proper recognition of the particular structures that form the triangle of Calot is essential for the proper and safe performance of laparoscopic cholecystectomy. Proper recognition, ligation, and cut of the cystic duct and cystic artery with branches (dorsal and ventral) remain an integral condition for the removal of the gallbladder. Calot's triangle, as an orientation structure, determines the most common location of the cystic artery. The triangle of Calot is one of the most variable regions of the abdomen in terms of anatomy. The aim of this study was to evaluate how important for surgery is the detailed anatomical recognition of the main branches of the cystic artery in Calot's triangle during laparoscopic cholecystectomy. Relations of the main branches of the cystic artery were evaluated in 88 patients that underwent laparoscopic cholecystectomy at the Department of General Surgery of the District Specialistic Hospital of Lublin. The anatomical relations of cystic duct and artery were classified into typical and variant types. Significantly more frequently variants of cystic artery were observed in women. However, the time of the procedure was not significantly related with the type of cystic artery.

[Value of identification of cystic duct, common bile duct, and common hepatic duct in prevention of bile duct injury during laparoscopic cholecystectomy].

OBJECTIVE: To explore effective method to avoid iatrogenic bile duct injury during laparoscopic cholecystectomy (LC). METHODS: 10 492 patients underwent LC from May 1996 to May 2006, 8566 of them were treated by the method to identify the cystic duct, common hepatic duct, and common bile duct during LC (tri-duct method group), and the left 1926 cases whose cystic duct failed to be exposed easily were treated with the method to identify at least two of the 4 structures (cystic lymph node, Hartmann's pouch, cystic artery, and emptiness of cystic triangle) so as to help identify the cystic duct (tri-duct plus tri-structure group). The operating time, amount of blood loss, open conversion rate, and morbidity were compared between these 2 groups. RESULTS: No cases of bile leakage or jaundice because of accidental injury of bile duct were found. The operating time of the tri-duct plus tri-structure group was (28 +/- 12) (15 - 52) min, significantly shorter than that of the tri-duct group [(38 +/- 16) (15 - 92) min, P < 0.05]. The open conversion rate of the tri-duct plus tri-structure group was 1.8%, significantly lower than that of the tri-duct group (8.7%, P < 0.05). There were no significant difference in the amount of blood loss and morbidity between the two groups (both P > 0.05). CONCLUSION: The tri-structure method can not only confirm the cystic duct correctly, thus preventing iatrogenic bile duct injury, but also shorten the operating time and reduce the open conversion ratio during LC.

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.

Surgical anatomy of innervation of the gallbladder in humans and Suncus murinus with special reference to morphological understanding of gallstone formation after gastrectomy.

AIM: To clarify the innervation of human gallbladder, with special reference to morphological understanding of gallstone formation after gastrectomy. METHODS: The liver, gallbladder and surrounding structures were immersed in a 10 mg/L solution of alizarin red S in ethanol to stain the peripheral nerves in cadavers (n=10). Innervation in the areas was completely dissected under a binocular microscope. Similarly, innervation in the same areas of 10 Suncus murinus (S. murinus) was examined employing whole mount immunohistochemistry. RESULTS: Innervation of the gallbladder occurred predominantly through two routes. One was from the anterior hepatic plexus, the innervation occurred along the cystic arteries and duct. Invariably this route passed through the hepatoduodenal ligament. The other route was from the posterior hepatic plexus, the innervation occurred along the cystic duct ventrally. This route also passed through the hepatoduodenal ligament dorsally. Similar results were obtained in S. murinus. CONCLUSION: The route from the anterior hepatic plexus via the cystic artery and/or duct is crucial for preserving gallbladder innervation. Lymph node dissection specifically in the hepatoduodenal ligament may affect the incidence of gallstones after gastrectomy. Furthermore, the route from the posterior hepatic plexus via the common bile duct and the cystic duct to the gallbladder should not be disregarded. Preservation of the plexus may attenuate the incidence of gallstone formation after gastrectomy.

Intraoperative cholangiography: past, present, and future.

The extrahepatic biliary tree was first visualized in 1918 when Reich injected bismuth and petrolatum and defined a biliary fistula, thus opening the field for further studies of the biliary tree. Mirizzi recorded the first series of intraoperative cholangiography in 1932 using static films. Later, the mobile C-arm image intensifier using a TV monitor was reported in a series by Berci and colleagues in 1978. They emphasized the importance of using routine cholangiography in all laparoscopic cholecystectomies. This procedure can be performed through the cystic duct or through the gallbladder with excellent visualization of the anatomy of the extrahepatic biliary tree, including the potential of finding bile duct stones, stricture, and tumor, as well as defining the function and anatomy of Oddi's sphincter. Numerous benefits of this technique can be observed, including early definition of a bile duct leak or injury. X-ray resolution will continue to improve as well as three-dimensional imaging, and intraoperative magnetic imaging cholangiopancreatography may be developed as the future intraoperative cholangiogram.

Extrahepatic biliary anatomy at laparoscopic cholecystectomy: is aberrant anatomy important?

BACKGROUND: The prevention of major duct injury at cholecystectomy relies on the accurate dissection of the cystic duct and artery, and avoidance of major adjacent biliary and vascular structures. Innumerable variations in the anatomy of the extrahepatic biliary tree and associated vasculature have been reported from radiographical and anatomical studies, and are cited as a potential cause of bile duct injury at cholecystectomy. METHODS: A photographic study of the dissected anatomy of 186 consecutive cholecystectomies was undertaken and each photo analysed to assess the position of the cystic duct and artery, the common bile duct and any anomalous structures. RESULTS: The anatomy in the region of the gallbladder neck was relatively constant. Anatomical variations were uncommon and anomalous ducts were not seen. Vascular variations were the only significant abnormalities found in the present series. CONCLUSION: Anatomy in the region of the gallbladder neck varies mostly in vascular patterns. Aberrant ducts or duct abnormalities are rarely seen during cholecystectomy hightlighting the principle that careful dissection and identification is the key to safe cholecystectomy.

Value of contrast-enhanced magnetic resonance cholangiography in patients undergoing laparoscopic cholecystectomy.

Laparoscopic cholecystectomy (LC) is the preferred treatment of symptomatic gallstone disease. Biliary injury during LC is still a serious problem. Knowledge of anatomic detail is important for not encountering the injury. Magnetic resonance cholangiography (MRC) is a noninvasive method for imaging the biliary ducts. However, MRC has many drawbacks such as not showing anatomic structures in detail and respiratory motion. In this study, contrast-enhanced MRC is used to show cystic ducts that are not seen by MRC. Reasons for patient referral for MRC and contrast-enhanced MRC included suspicion of cholecystolithiasis, adenomyomatosis, and gallbladder polyp. Our results show that routine MRC revealed cystic ducts in 38 patients (77.5%) and contrast-enhanced MRC in 46 patients (93.8%). Intraoperative cholangiography (IOC) was taken as gold standard for all patients. We found that contrast-enhanced MRC can provide a useful supplement to MRC in patients with nonvisualized cystic ducts by MRC. To our knowledge, this is the first study of visualization of cystic duct in patients undergoing LC depicted by both MRC and contrast-enhanced MRC.

Fiberoptic intraluminal transillumination of the cystic duct and the common bile duct.

We have developed two new fiberoptic instructions for outlining the anatomic characteristics of the extrahepatic biliary tree. By transilluminating the common and cystic ducts and duodenum, any obstruction or pathologic abnormalities can be visualized and located. These instruments can be used instead of intraoperative cholangiography when indicated.

Avoidance of bile duct injury during laparoscopic cholecystectomy.

Common bile duct (CBD) injury during laparoscopic cholecystectomy appears to have a higher incidence than during open cholecystectomy. This may be a function of inadequate instruction, inadequate caution, or inexperience, or may represent an inherent flaw in laparoscopic exposure. The aim of this study was to identify several steps in laparoscopic exposure of the gallbladder, cystic duct, and Calot's triangle to minimize the risk of surgical disorientation and CBD injury. A review of the first 180 laparoscopic cholecystectomies from the author's series was performed. Maneuvers that provided optimal exposure of the critical anatomy were culled from the video record. These maneuvers were (1) routine use of a 30 degree forward oblique viewing telescope, (2) firm cephalic traction on the fundus of the gallbladder to reduce redundancy in the infundibulum of the gallbladder and best expose the cystic duct, (3) lateral traction on the infundibulum of the gallbladder to place the cystic duct perpendicular to the CBD, (4) dissection of the cystic duct at the infundibulum of the gallbladder, and (5) routine fluoroscopic cholangiography. If these steps do not provide the surgeon with comfortable anatomic orientation, the procedure should be converted to open cholecystectomy.