Robotically assisted augmented reality system for identification of targeted lymph nodes in laparoscopic gynecological surgery: a first step toward the identification of sentinel node : Augmented reality in gynecological surgery.

BACKGROUND: To prove feasibility of multimodal and temporal fusion of laparoscopic images with preoperative computed tomography scans for a real-time in vivo-targeted lymph node (TLN) detection during minimally invasive pelvic lymphadenectomy and to validate and enable such guidance for safe and accurate sentinel lymph node dissection, including anatomical landmarks in an experimental model. METHODS: A measurement campaign determined the most accurate tracking system (UR5-Cobot versus NDI Polaris). The subsequent interventions on two pigs consisted of an identification of artificial TLN and anatomical landmarks without and with augmented reality (AR) assistance. The AR overlay on target structures was quantitatively evaluated. The clinical relevance of our system was assessed via a questionnaire completed by experienced and trainee surgeons. RESULTS: An AR-based robotic assistance system that performed real-time multimodal and temporal fusion of laparoscopic images with preoperative medical images was developed and tested. It enabled the detection of TLN and their surrounding anatomical structures during pelvic lymphadenectomy. Accuracy of the CT overlay was > 90%, with overflow rates < 6%. When comparing AR to direct vision, we found that scores were significatively higher in AR for all target structures. AR aided both experienced surgeons and trainees, whether it was for TLN, ureter, or vessel identification. CONCLUSION: This computer-assisted system was reliable, safe, and accurate, and the present achievements represent a first step toward a clinical study.

Fluoroless intravascular ultrasound image-guided liver navigation in porcine models.

BACKGROUND: An intravascular ultrasound catheter (IVUSc) was developed for intracardiac ultrasound to assess interventions with compelling results. However, intrahepatic vascular exploration was rarely tested and was always associated with X-ray techniques. The aim of this study was to demonstrate the feasibility to navigate through the whole liver using an IVUSc, providing high-quality images and making it unnecessary to use ionizing radiation. METHODS: An ex vivo pig visceral block and an in vivo pig model were used in this study. The IVUS equipment was composed of an US system, and of an 8 French lateral firing IVUSc capable of producing 90-degree sector images in the longitudinal plane. After accessing the intravascular space with the IVUSc into the models, predetermined anatomical landmarks were visualized from the inferior vena cava and hepatic veins and corroborated. RESULTS: IVUS navigation was achieved in both models successfully. The entire navigation protocol took 87 and 48 min respectively, and 100% (21/21) and 96.15% (25/26) of the landmarks were correctly identified with the IVUSc alone in the ex vivo and in vivo models respectively. IVUS allowed to clearly visualize the vasculature beyond third-order branches of the hepatic and portal veins. CONCLUSIONS: A complete IVUS liver navigation is feasible using the IVUSc alone, making it unnecessary to use ionizing radiation. This approach provides high-definition and real-time images of the complex liver structure and offers a great potential for future clinical applications during diagnostic and therapeutic interventions.

Percutaneous transhepatic cholangioscopy using a single-operator cholangioscope (pSOC), a retrospective, observational, multicenter study.

BACKGROUND AND AIMS: Percutaneous cholangioscopy (PC) is more complex and invasive than a transpapillary approach, with the need for a large percutaneous tract of 16 French (Fr) on average in order to advance standard percutaneous cholangioscopes. The aim of this study was to investigate whether percutaneous single-operator cholangioscopy (pSOC) using the SpyGlass™ DS system is feasible, safe, and effective in PC for diagnostic and therapeutic indications. MATERIALS AND METHODS: The data of 28 patients who underwent pSOC in 4 tertiary referral centers were retrospectively analyzed. Technical and clinical success for therapeutic procedures was assessed as well as diagnostic accuracy of pSOC-guided biopsies and visualization. Adverse events and the required number and size of dilatations were reviewed. RESULTS: 25/28 (89%) patients had a post-surgical altered anatomy. The average number of percutaneous dilatations prior to pSOC was 1.25 with a mean dilatation size of 11 French. Histopathology showed a 100% accuracy. Visual impression showed an overall accuracy of 96.4%. Technical and clinical success was achieved in 27/28 (96%) of cases. Adverse events occurred in 3/28 (10.7%) cases. CONCLUSION: pSOC is a feasible, safe, and effective technique for diagnostic and therapeutic indications. It may be considered an alternative approach in clinical cases where gastrointestinal anatomy is altered. It has the potential to reduce peri-procedural adverse events and costs. Prospective randomized-controlled trials are necessary to confirm the previously collected data.

COVID-19 Efforts at the Institute of Image Guided Surgery (IHU-Strasbourg): 2020.

We submit a summary of some of the activities of the IHU-Strasbourg during the initial period of the COVID-19 pandemic. These were presented as part of the coronnavation effort coordinated by Dr Adrian Park. Three initiatives are presented as follows: Protect-Est App, healthcare worker stress, and converted diving mask for ventilation. Two of the 3 projects are still ongoing, and one (Predoict-Est) has been adopted nationally.

Duodenal injuries due to trauma: Review of the literature.

Duodenal injuries constitute a challenge to the Trauma Surgeon, mainly due to their retroperitoneal location. When identified, they present associated with other abdominal injuries. Consequently, they have an increased morbidity and mortality. At best estimates, duodenal lesions occur in 4.3% of all patients with abdominal injuries, ranging from 3.7% to 5%, and because of their anatomical proximity to other organs, they are rarely an isolated injury. The aim of this paper is to present a concise description of the anatomy, diagnosis, surgical management and treatment of complications of duodenal trauma, and an analysis of complications and mortality rates of duodenal injuries based on a 46-year review of the literature.

[Risk factors associated with the diagnosis of chronic Chagasic miocardiopathy in seropositive individuals from Barinas state, Venezuela]. / Factores de riesgo asociados con el diagnóstico de miocardiopatía chagásica crónica en individuos seropositivos del estado Barinas, Venezuela.

This study evaluates the risk factors associated with the diagnosis of chronic chagasic miocardiopathy (CChM) in 115 seropositive individuals to anti-Trypanosoma cruzi antibodies, in Barinas state, Venezuela. Serology was performed with ELISA and MABA; while the CChM diagnosis was established by electrocardiography and echocardiography. A complete clinical history including epidemiological, personal/familiar antecedents and psychobiological habits, plus socioeconomic, psychosocial and alimentary habits interviews were performed for each individual. Risk factors were determined through binary logistic regression. Results showed that 81 patients (70,4%; CI 95% = 66.4-74.4) had criteria for CChM, of which 74 (64.4%; IC 95% = 60.2-68.6) were in phase II; while 34 (29.6%; IC 95% = 25.5-33.5) were in phase I of the disease and 7 (6.1%; IC 95% = 4.0-8.2) in phase III. In a one year period, two patients in phase III died of heart failure. The diagnosis of CChM was associated with hunting practice, maternal history of cardiopathies, chewing chimó, medical history of hypertension and apex beat visible; it was negatively associated with canned and preserved foods ingest. In conclusion the CChM diagnosis has high frequency in seropositive individuals in Barinas and heart failure prevention must be based on an early medical attention and educative strategies in order to control risk factors.

Prevalence of cholelithiasis in Buenos Aires, Argentina.

BACKGROUND: Cholelithiasis is an important cause of morbidity in the world and it varies significantly depending on the region of study. OBJECTIVE: To assess the prevalence of cholelithiasis in Buenos Aires. MATERIAL AND METHODS: This is a cross-sectional, descriptive, observational study performed in a public hospital with tertiary care in Gastrointestinal Surgery. From July 2010 to December 2011, 1,875 healthy volunteers who underwent liver, gallbladder and pancreas ultrasound imaging were included and a questionnaire containing the individual's medical history was administered. The presence of cholelithiasis and its eventual risk factors were studied. RESULTS: Of 1,875 individuals, 866 were males (46.2%) and 1,009 females (53.8%), older than 20 years old with an average age of 46.1 + 16.7 years. Cholelithiasis was found in 410 inidviduals (21.9%); 285 (15.2%) diagnosed at the time of the study and 125 (67%) who had already undergone a cholecystectomy due to gallstones. CONCLUSIONS: The prevalence of cholelithiasis in Buenos Aires, capital city of Argentina, is 21.9%. A significant association was found between cholelithiasis and female gender, age, body mass index, history of colic pain, family history of cholelithiasis, smoking, fatty liver and number of pregnancies.

Preliminary Results of Laser Ablation during In Vivo Experiments: Comparison of Thermal Effects Obtained with Bare and Diffuser Tip Applicators.

This work is a step towards the analysis of the effect of different laser applicator tips used for laser ablation of liver for in vivo experiments. As the thermal outcome of this minimally invasive treatment for tumors depends upon the interaction between the tissue and the light, the emission pattern of the laser applicator has a key role in the shape and size of the final treated region. Hence, we have compared two different laser applicators: a bare tip fiber (emitting light from the tip and forward) and a diffuser tip fiber (emitting light at 360° circumferentially from the side of the fiber). The experiments have been carried out percutaneously in a preclinical scenario (anesthetized pigs), under computed tomography (CT) guidance. The thermal effects of the two applicators have been assessed in terms of real-time temperature distribution, by means of an array of 40 fiber Bragg grating (FBG) sensors, and in terms of cavitation and ablation volumes, measured through CT post-temperature due to breathing motion has been analyzed and filtered out. Results show that the maximum temperature reached 50.5 °C for the bare tip fiber experiment (measured at 6.24 mm distance from the applicator) and 60.9 °C for the diffuser tip fiber experiment (measured at 5.23 mm distance from the applicator). The diffuser tip fiber allowed to achieve a more symmetrical heat distribution than the bare tip fiber, and without cavitation volume.Clinical Relevance-This work shows the analysis of the thermal effects of different laser fiber tips to improve laser ablation treatment. The results obtained in the preclinical scenario well represent the expected clinical outcome in the treatment of hepatic tumors. Moreover, these findings can be applied to other fields in which laser ablation is the optimal therapeutic choice, such as neurosurgery.

Live laparoscopic video retrieval with compressed uncertainty.

Searching through large volumes of medical data to retrieve relevant information is a challenging yet crucial task for clinical care. However the primitive and most common approach to retrieval, involving text in the form of keywords, is severely limited when dealing with complex media formats. Content-based retrieval offers a way to overcome this limitation, by using rich media as the query itself. Surgical video-to-video retrieval in particular is a new and largely unexplored research problem with high clinical value, especially in the real-time case: using real-time video hashing, search can be achieved directly inside of the operating room. Indeed, the process of hashing converts large data entries into compact binary arrays or hashes, enabling large-scale search operations at a very fast rate. However, due to fluctuations over the course of a video, not all bits in a given hash are equally reliable. In this work, we propose a method capable of mitigating this uncertainty while maintaining a light computational footprint. We present superior retrieval results (3%-4% top 10 mean average precision) on a multi-task evaluation protocol for surgery, using cholecystectomy phases, bypass phases, and coming from an entirely new dataset introduced here, surgical events across six different surgery types. Success on this multi-task benchmark shows the generalizability of our approach for surgical video retrieval.

Characterization of susceptibility artifacts in magnetic resonance thermometry images during laser interstitial thermal therapy: dimension analysis and temperature error estimation.

Objective.Laser interstitial thermal therapy (LITT) is a minimally invasive procedure used to treat a lesion through light irradiation and consequent temperature increase. Magnetic resonance thermometry imaging (MRTI) provides a multidimensional measurement of the temperature inside the target, thus enabling accurate monitoring of the damaged zone during the procedure. In proton resonance frequency shift-based thermometry, artifacts in the images may strongly interfere with the estimated temperature maps. In our work, after noticing the formation of the dipolar-behavior artifact linkable to magnetic susceptibility changes duringin vivoLITT, an investigation of susceptibility artifacts in tissue-mimicking phantoms was implemented.Approach.The artifact was characterized: (i) by measuring the area and total volume of error regions and their evolution during the treatment; and (ii) by comparison with temperature reference provided by three temperature sensing needles. Lastly, a strategy to avoid artifacts formation was devised by using the temperature-sensing needles to implement a temperature-controlled LITT.Main results.The artifact appearance was associated with gas bubble formation and with unwanted treatment effects producing magnetic susceptibility changes when 2 W laser power was set. The analysis of the artifact's dimension demonstrated that in the sagittal plane the dipolar-shape artifact may consistently spread following the temperature trend until reaching a volume 8 times bigger than the ablated one. Also, the artifact shape is quite symmetric with respect to the laser tip. An absolute temperature error showing a negative Gaussian profile in the area of susceptibility artifact with values up to 64.4 °C was estimated. Conversely, a maximum error of 2.8 °C is measured in the area not-affected by artifacts and far from the applicator tip. Finally, by regulating laser power, susceptibility artifacts formation was avoided, and appreciable thermal damage was induced.Significance.These findings may help in improving the MRTI-based guidance of thermal therapies.

Organ-based estimation and minimization of clinician's X-ray dose.

PURPOSE: Hybrid surgeries, allowing real-time visualization of patient inner anatomy, are possible through the use of intraoperative X-ray imaging. However, the intensive use of X-rays can have undesired consequences for the clinicians or the patient in the operating room (OR). METHODS: In this paper, we provide a tool to visualize the X-rays and to optimally place protective shields in the hybrid operating room to reduce the clinician's dose according to their most sensitive body parts. We first acquire measurements in a hybrid operating room with dosimeters placed at different locations on a mannequin simulating a clinician. We demonstrate that a small displacement of a protective shield has significant consequences on the dose received by a clinician. Then, we reproduce the scene virtually and use Monte Carlo simulations to estimate the dose received by the clinician. Finally, we optimally place protective shields with a Nelder-Mead-based numerical optimization algorithm. RESULTS: The results show a high sensitivity of the clinician's dose to protective shield placement. Numerical optimization of the shields' placement can help to reduce the dose and show a decrease between 79 and 89% of the exposition when comparing no external shield protection and our optimal external shield position. CONCLUSION: Our work can help to raise awareness of the risks induced by X-rays during intraoperative surgery and reduce the dose received by the clinicians. In future work, our approach can be linked with human pose estimation algorithms to trace surgeons' moves, estimate dynamically the dose and summarize it in a surgical report, giving the dose for important organs.

Development and validation of a novel porcine bile duct dilation model for EUS training.

Background and study aims Image-guided minimally invasive techniques have transformed the management of malignant and benign bile duct obstructions. These evolving techniques are being widely adopted and applied and hands-on training using high quality models is required to improve the proficiency of practitioners. This experimental study aimed to validate an in vivo porcine model created to simulate bile duct dilation for interventional endoscopic ultrasound (EUS) hands-on training curriculums. Materials and methods Thirty-six porcine models were involved and the procedures were performed in an experimental hybrid operating room under general anesthesia. Animals underwent endoscopic duodenal papilla clipping with several hemostatic metallic clips. After a survival period of 24 to 48 hours, the models with effective intrahepatic and extrahepatic bile duct dilatation were included in the hands-on training. Trainees and faculty were given structured evaluations of the model realism and usefulness. Results Extrahepatic bile duct and gallbladder dilation was achieved in all 36 of the models, and in 11 of the 36 models, a treatable intrahepatic duct dilatation was achieved. During the hands-on training, EUS-guided biliary drainage, EUS-guided transgastric gallbladder drainage, and EUS through-the-needle microbiopsy forceps procedures were feasible. Overall, 75 % of the experts and trainees evaluated the training as excellent. Conclusions We present a minimally invasive, reliable and time- effective model of extrahepatic dilation suitable for interventions. The model was less effective for intrahepatic ducts, which should be considered if intrahepatic biliary dilation is required for training.

Preoperative SPECT/CT + intraoperative CT fusion enabling surgical augmented reality to target sentinel lymph node in endometrial cancer.

PURPOSE: To establish a proof-of-concept study using a phantom model to allow the fusion of preoperative single-photon emission computed tomography (SPECT) combined with computed tomography (CT), also known as SPECT/CT, with intraoperative CT, enabling the application of an augmented reality (AR) surgical guidance system for pelvic sentinel lymph node (SLN) detection in endometrial cancer patients. METHODS: A three-dimensional (3D) pelvic phantom model printed in a gelatin-based scaffold including a radiopaque pelvis, a vascular tree mimicking the iliac vessels, two 3D-printed fillable spheres representing the target pelvic sentinel lymph nodes, and a calibration board was developed. A planar with SPECT/CT lymphoscintigraphy and CT were performed independently on the model. We performed all the necessary steps to achieve the fusion between SPECT/CT and CT. Then, we performed a laparoscopy of the pelvic anatomy on the phantom model to assess in real time the overlay of the recording on the anatomical structures and AR guidance system performance. RESULTS: We have successfully completed all the steps needed to fuse the two imaging procedures. This allowed us to apply, in real time, our surgical guidance system with the coverage rate of the visible surface by the augmented reality surface, respectively, on the left SLN 99.48% and on the right SLN 99.42%. CONCLUSION: Co-registration and real-time fusion between a preoperative SPECT/CT and intraoperative CT are feasible. The metric performance of our guidance system is excellent in relation to possible SPECT/CT and CT fusion. Based on our results, we are able to translate the technology to patients, and we initiated a clinical study to evaluate the accuracy of the AR guidance system for endometrial cancer surgery, with a correlation with indocyanine green (ICG)-based technique, representing the gold standard today in the intraoperative detection of SLN in endometrial cancers, despite various limitations.

Why non-technical skills matter in surgery. New paradigms for surgical leaders.

The surgical literature is paying more and more attention to the topic of soft or non-technical skills (NTS), defined as those cognitive and social skills that characterize high-performing individuals and teams. NTS are essential in supporting surgeons in dealing with unexpected situations. During the COVID-19 pandemic, NTS have been considered crucial in defining situation awareness, enhancing decision making, communicating among groups and teams, and fostering leadership. With a "looking back and planning forward" approach, the current perspective aims at deepening the contribution of NTS for surgeons to deal with the unexpected challenges posed by the COVID crisis, surgical emergencies, the introduction of new technologies in clinical practice, to understand how such skills may help shape the surgical leaders of the future.

Artificial Intelligence and Surgery: Ethical Dilemmas and Open Issues.

BACKGROUND: Artificial intelligence (AI) applications aiming to support surgical decision-making processes are generating novel threats to ethical surgical care. To understand and address these threats, we summarize the main ethical issues that may arise from applying AI to surgery, starting from the Ethics Guidelines for Trustworthy Artificial Intelligence framework recently promoted by the European Commission. STUDY DESIGN: A modified Delphi process has been employed to achieve expert consensus. RESULTS: The main ethical issues that arise from applying AI to surgery, described in detail here, relate to human agency, accountability for errors, technical robustness, privacy and data governance, transparency, diversity, non-discrimination, and fairness. It may be possible to address many of these ethical issues by expanding the breadth of surgical AI research to focus on implementation science. The potential for AI to disrupt surgical practice suggests that formal digital health education is becoming increasingly important for surgeons and surgical trainees. CONCLUSIONS: A multidisciplinary focus on implementation science and digital health education is desirable to balance opportunities offered by emerging AI technologies and respect for the ethical principles of a patient-centric philosophy.

Analysis of cavitation artifacts in Magnetic Resonance Imaging Thermometry during laser ablation monitoring.

Magnetic Resonance Thermometry Imaging (MRTI) holds great potential in laser ablation (LA) monitoring. It provides the real-time multidimensional visualization of the treatment effect inside the body, thus enabling accurate intraoperative prediction of the thermal damage induced. Despite its great potential., thermal maps obtained with MRTI may be affected by numerous artifacts. Among the sources of error producing artifacts in the images., the cavitation phenomena which could occur in the tissue during LA induces dipole-structured artifacts. In this work., an analysis of the cavitation artifacts occurring during LA in a gelatin phantom in terms of symmetry in space and symmetry of temperature values was performed. Results of 2 Wand 4 W laser power were compared finding higher symmetry for the 2 W case in terms of both dimensions of artifact-lobes and difference in temperature values extracted in specular pixels in the image. This preliminary investigation of artifact features may provide a step forward in the identification of the best strategy to correct and avoid artifact occurrence during thermal therapy monitoring. Clinical Relevance- This work presents an analysis of cavitation artifacts in MRTI from LA which must be corrected to avoid error in the prediction of thermal damage during LA monitoring.

Predictors of mortality in patients with rib fractures.

BACKGROUND: The aim of this study was to identify risk factors for morbidity and mortality in patients with rib fractures with focus on identifying a more exact age-dependent cut-off for increased morbidity and mortality. METHODS: Retrospective study of patients 16 years or older with rib fractures from blunt trauma. EXCLUSION CRITERIA: patients undergoing rib plating. Initial chest X-ray and Computed Tomography (CT) scans were re-read for the number of rib fractures (NRF) and presence of pulmonary contusion (PC). Data included demographics, mechanism of injury (MOI), NRF, associated injuries, Injury Severity Score (ISS), Glasgow Coma Scale (GCS), Geriatric Trauma Outcome Score (GTOS), presence of pneumothorax, hemothorax, hemo-pneumothorax, PC, Adult Respiratory Distress Syndrome (ARDS), pulmonary complications (ventilator-associated pneumonia, nosocomial pneumonia), and mortality. PC was quantified from CT scans with Mimics. Continuous data were analyzed using Student's t test. Variables significantly different by univariate analysis were analyzed by logistic regression analysis. RESULTS: The study group consisted of 1188 adult trauma patients admitted during a 2-year period; 800 males and 388 females, with a mean age of 54 ± 21. MOI: MVC, 735 (61.8%); falls, 364 (30.6%); other: 89. Mean NRF, 4 ± 2; GCS, GTOS, and ISS, 15 (15-15), 101 (82-124), and 19 ± 9, respectively. Incidence of PC was 329 (27.7%); PTX, HTX, and HTX/PTX, 264 (20.2%), 57 (4.8%), and 147 (12.4%). Flail chest, in 17 (1.4%); 321 required mechanical ventilation. Age, GCS, male gender, and ISS but not NRF and/or PC were predictive of mortality. CONCLUSIONS: Increased mortality in patients with rib fractures starts at 65 years of age without a further increase until age ≥ 80. NRF does not predict increased mortality independent of age. Severe TBI is the most common cause of death in patients 16-75 years, as opposed to respiratory complications in patients 80 years-old or greater.

Image-Guided Surgical Simulation in Minimally Invasive Liver Procedures: Development of a Liver Tumor Porcine Model Using a Multimodality Imaging Assessment.

Background: Image-guided liver surgery and interventions are growing as part of the current trend to translate liver procedures into minimally invasive approaches. Hands-on surgical training in such techniques is required. Consequently, a meaningful and realistic liver tumor model using multi-imaging modalities, such as ultrasound (US), computed tomography (CT), magnetic resonance (MR), cone beam-CT (CBCT), is mandatory. The first aim of this study is to develop a novel tumor-mimic model and assess it with multi-imaging modalities. The second aim is to evaluate the usefulness of the model during image-guided liver procedures. Materials and Methods: The tumor-mimic model is made of a composition of hydrogel, smashed muscle, and gadolinium contrast solution. Five ex vivo livers and three pigs were included in the study. Procedures were performed in an experimental hybrid operating room. Under general anesthesia, US guidance was required to inject the biotumor formula into the pig's liver. US, CT, CBCT, and MR acquisitions were then performed after the initial injection. In vivo models were then used to perform liver procedures, including US-guided biopsy, radiofrequency ablation, and laparoscopic resection. Results: The formula developed is easily injected generating a tissue-like material. Visualization using multi-imaging modalities was appropriate, thereby allowing to perform image-guided techniques. Conclusion: A novel design of an in vivo and ex vivo tissue-like tumor liver model is presented. Due to the multimodality imaging appraisal, it may provide a realistic and meaningful model allowing to perform image-guided liver procedures.

Image-Guided Surgical Training in Percutaneous Hepatobiliary Procedures: Development of a Realistic and Meaningful Bile Duct Dilatation Porcine Model.

Background: Malignant or benign biliary obstructions can be successfully managed with minimally invasive percutaneous interventions. Since percutaneous approaches are challenging, extensive training using relevant models is fundamental to improve the proficiency of percutaneous physicians. The aim of this experimental study was to develop an in vivo training model in pigs to simulate bile duct dilatation to be used during percutaneous biliary interventions. Materials and Methods: Twenty-eight large white pigs were involved and procedures were performed in an experimental hybrid operating room. Under general anesthesia, animals underwent a preoperative magnetic resonance cholangiography (MRC). Afterward, the common bile duct was isolated and ligated laparoscopically. A postoperative MRC was performed 72 hours after the procedure to evaluate bile duct dilatation. The In vivo models presenting an effective dilatation model were included in the hands-on part of a percutaneous surgery training course. Animals were euthanized at the end of the training session. Results: Postoperative MRC confirmed the presence of bile duct dilatation in the survival pigs (n = 25). No intraoperative complications occurred and mean operative time was 15.8 ± 5.27 minutes. During the course, 27 trainees could effectively perform percutaneous transhepatic cholangiography, bile duct drainage, biliary duct dilatation, and stent placement, with a > 90% success rate, thereby validating the experimental model. All animals survived during the training procedures and complications occurred in 28.3% of cases. Conclusion: The creation of an in vivo bile duct dilatation animal model is feasible with a low short-term mortality. It provides a realistic and meaningful training model in percutaneous biliary procedures.