Safety and benefit of modified mesohepatectomy in the treatment of bilobar involvement congenital biliary dilatation.

BACKGROUND: The diseased bile duct in bilobar congenital biliary dilatation is extensive and often requires major hepatectomy or liver transplantation associated with a higher risk. We aimed to evaluate the safety and benefit of modified mesohepatectomy, in comparison with trisectionectomy, to treat bilobar congenital biliary dilatation. METHODS: This study included 28 patients with type IV and V bilobar congenital biliary dilatation. An innovative mesohepatectomy comprising the hepatectomy technique beyond the P/U point and bile duct shaping was applied to 14 patients to address the extensively diseased bile duct and difficulty in hepaticojejunostomy. Another 14 patients received trisectionectomy. The perioperative and long-term outcomes of these patients were compared. RESULTS: The ratio of residual liver volume to standard liver volume in the mesohepatectomy group was higher (78.68% vs. 40.90%, p = 0.005), while the resection rate of the liver parenchyma was lower (28.25% vs. 63.97%, p = 0.000), than that in trisectionectomy group. The mesohepatectomy group had a lower severe complication (>Clavein III, 0% vs. 57.70%, p = 0.019) and incidence of posthepatectomy liver failure (7.14% vs. 42.86%, p = 0.038). No significant difference was observed in blood loss and bile leakage (p > 0.05). All the patients in the mesohepatectomy group achieved optimal results in the long-term follow-up. CONCLUSIONS: mesohepatectomy provides an efficient treatment option for bilobar congenital biliary dilatation and can achieve radical resection, retain more liver parenchyma, and reduce the difficulty of hepaticojejunostomy, especially for patients that are not eligible for major hepatectomy and liver transplantation.

Efficacy of radiotherapy in combined treatment of hepatocellular carcinoma patients with portal vein tumor thrombus: a real-world study.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) has an extremely poor prognosis. A previous study proved that low-dose radiotherapy (RT) could prolong the prognosis of HCC patients with PVTT. This study aims to explore the sensitivity of PVTT to RT treatment. METHODS: Patients were selected based on imaging diagnosis of HCC accompanied by PVTT and received combined treatment of radiotherapy, antiangiogenic drugs and immune checkpoint inhibitors, followed by hepatectomy or liver transplantation from January 2019 to August 2022. The efficacy was evaluated by Response Evaluation Criteria in Solid Tumors (RECIST) guidelines and pathological assessment. The sensitivity of tumor cells to the treatment was compared between the primary tumor (PT)and PVTT by analyzing their residual tumor and pathologic complete remission (PCR) incidence. RESULTS: Data from 14 patients were collected in the study. After combined treatment, the size of PVTT decreased more significantly than that of the primary tumor in the imaging study (p < 0.05). The residual cancer was significantly more restrictive than that of primary tumor in paired patients based on pathological measurement (p = 0.008). The PCR incidence of the primary tumor (21.42%) was significantly lower (p = 0.008) than that of PVTT in the pathologic study (78.57%). CONCLUSION: PVTT is more sensitive to radiotherapy treatment than the primary tumor in patients with HCC. This combination therapy might be an effective option as a downstaging therapy for patients with HCC with PVTT.

Comparing the distal pancreatectomy fistula risk score (D-FRS) and DISPAIR-FRS for predicting pancreatic fistula after distal pancreatectomy.

BACKGROUNDS: Distal pancreatectomy fistula risk score (D-FRS) and DISPAIR-FRS has not been widely validated for predicting postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP). METHODS: We retrospectively analysed 104 patients undergoing DP. The predictive value of the D-FRS and DISPAIR-FRS were compared. Risk factors associated with POPF were investigated by multivariate analysis. RESULTS: Of the 104 patients, 23 (22.1%) were categorized into the POPF group (all grade B). The areas under the ROC (AUCs) of the D-FRS (preoperative), D-FRS (intraoperative), and DISPAIR-FRS were 0.737, 0.809, and 0.688, respectively. Stratified by the D-FRS (preoperative), the POPF rates in low-risk, intermediate-risk, and high-risk groups were 5%, 22.6%, and 36.4%, respectively. By the D-FRS (intraoperative), the POPF rates in low-risk, intermediate-risk, and high-risk groups were 8.8%, 47.1%, and 47.4%, respectively. By the DISPAIR-FRS, the POPF rates in low-risk, intermediate-risk, and extreme-high-risk groups were 14.8%, 23.8% and 62.5%, respectively. Body mass index and main pancreatic duct diameter were independent risk factors of POPF both in preoperative (P = 0.014 and P = 0.033, respectively) and intraoperative (P = 0.015 and P = 0.039) multivariate analyses. CONCLUSION: Both the D-FRS (preoperative), D-FRS (intraoperative), and DISPAIR-FRS has good performance in POPF prediction after DP. The risk stratification was not satisfactory in current Asian cohort.

Comparing iodized oil with polyvinyl alcohol for portal vein embolization in promoting liver remnant increase before partial hepatectomy.

BACKGROUND: To compare the efficacy and safety of iodized oil versus polyvinyl alcohol (PVA) particles in portal vein embolization (PVE) before partial hepatectomy. METHODS: From October 2016 to December 2021, 86 patients who planned to undergo hepatectomy after PVE were enrolled, including 61 patients post-PVE with PVA particles + coils and 25 patients post-PVE with iodized oil + coils. All patients underwent CT examination before and 2-3 weeks after PVE to evaluate the future liver remnant (FLR). The intercohort comparison included the degree of liver volume growth, changes in laboratory data, and adverse events. RESULTS: There was no significant difference in the resection rate between the iodized oil group and the PVA particle group (68 % vs. 70 %, p = 0.822). In terms of the degree of hypertrophy (9.52 % ± 13.47 vs. 4.03 % ± 10.55, p = 0.047) and kinetic growth rate (4.07 % ± 5.4 vs. 1.55 % ± 4.63, p = 0.032), the iodized oil group was superior to the PVA group. The PVE operation time in the PVA particle group was shorter than that in the iodized oil group (121. 72 min ± 34.45 vs. 156. 2 min ± 71.58, p = 0.029). There was no significant difference in the degree of hypertrophy between the high bilirubin group and the control group (5.32 % ± 9.21 vs. 6.1 % ± 14.79, p = 0.764). Only 1 patient had a major complication. CONCLUSIONS: Compared with PVA particles, iodized oil PVE can significantly increase liver volume and the degree of hypertrophy without any significant difference in safety.

Effectiveness and Safety of the PD-1 Inhibitor Lenvatinib Plus Radiotherapy in Patients with HCC with Main PVTT: Real-World Data from a Tertiary Centre.

Background: Patients with hepatocellular carcinoma (HCC) with portal vein tumour thrombus (PVTT), especially type Vp-4, usually have a poor prognosis. However, the vast majority of Phase III clinical trials exclude this population based on the inclusion criteria. Lenvatinib plus a PD-1 inhibitor has shown promising antitumour activity and tolerable safety in patients with unresectable HCC in Asian populations. Radiotherapy has also demonstrated high response rates and favourable survival for HCC patients with PVTT. This study aimed to explore the preliminary clinical efficacy and safety of lenvatinib plus the PD-1 inhibitor combined with radiotherapy for HCC patients with main portal vein tumour thrombus. Methods: Between 1 March 2018 and 31 October 2020, HCC patients with main PVTT who received lenvatinib plus a PD-1 inhibitor (pembrolizumab, nivolumab or sintilimab) combined with radiotherapy from Beijing Tsinghua Changgung Hospital in China were reviewed for eligibility. The efficacy was evaluated by the survival and PVTT response rate, and the safety was evaluated by the frequency of key adverse events (AEs). Results: In total, 39 eligible HCC patients with type Vp-4 PVTT who received triple therapy were included in this study. The 2-year OS rate was 15.4%, which was the primary end-point of our study. The median overall survival (OS) and progression-free survival (PFS) were 9.4 months (range 2.3 to 57.1) and 4.9 months (range 1.4 to 36.1), respectively. The objective response rate (ORR) of PVTT based on mRECIST was 61.5%. AFP dropped to normal 3 months after radiotherapy and was an independent risk factor associated with OS. All AEs were controlled, and no treatment-related deaths occurred. Conclusion: Lenvatinib plus PD-1 inhibitor combined with radiotherapy had a significant therapeutic effect and manageable AEs in HCC patients with type Vp-4 PVTT and may be a potential treatment option for advanced HCC.

Advanced glycation end-products as mediators of the aberrant crosslinking of extracellular matrix in scarred liver tissue.

The extracellular matrix of cirrhotic liver tissue is highly crosslinked. Here we show that advanced glycation end-products (AGEs) mediate crosslinking in liver extracellular matrix and that high levels of crosslinking are a hallmark of cirrhosis. We used liquid chromatography-tandem mass spectrometry to quantify the degree of crosslinking of the matrix of decellularized cirrhotic liver samples from patients and from two mouse models of liver fibrosis and show that the structure, biomechanics and degree of AGE-mediated crosslinking of the matrices can be recapitulated in collagen matrix crosslinked by AGEs in vitro. Analyses via cryo-electron microscopy and optical tweezers revealed that crosslinked collagen fibrils form thick bundles with reduced stress relaxation rates; moreover, they resist remodelling by macrophages, leading to reductions in their levels of adhesion-associated proteins, altering HDAC3 expression and the organization of their cytoskeleton, and promoting a type II immune response of macrophages. We also show that rosmarinic acid inhibited AGE-mediated crosslinking and alleviated the progression of fibrosis in mice. Our findings support the development of therapeutics targeting crosslinked extracellular matrix in scarred liver tissue.

Free-breathing simultaneous water-fat separation and T1 mapping of the whole liver (SWALI) with isotropic resolution using 3D golden-angle radial trajectory.

Background: Conventional liver T1 mapping techniques are typically performed under breath-holding conditions; they have limited slice coverage and often rely on multiple acquisitions. Furthermore, liver fat affects the accuracy of T1 quantification. Therefore, we aim to propose a free-breathing technique for simultaneous water-fat separation and T1 mapping of the whole liver (SWALI) in a single scan. Methods: The proposed SWALI sequence included an inversion recovery (IR) preparation pulse followed by a series of multiecho three-dimensional (3D) golden-angle radial acquisitions. For each echo time (TE), a series of images containing a mix of water and fat were reconstructed using a sliding window method. For each inversion time (TI), water and fat were separated, and then water and fat T1 estimation was conducted. The fat fraction (FF) was calculated based on the last TI image. The FF and water T1 quantification accuracy were compared with the gold standard sequences in the phantom. The in vivo feasibility was tested in 9 healthy volunteers, 2 patients with fatty liver, and 3 patients with hepatocellular carcinoma (HCC). The reproducibility was evaluated in the patients with fatty liver and in the healthy volunteers. Results: The mean FF and the mean water T1 values obtained by the SWALI sequence showed good agreements with chemical shift-encoded magnetic resonance imaging (CSE-MRI; r=0.998; P<0.001) and fat-suppressed (FS) IR-spin echo (SE; r=0.997; P<0.001) in the phantom. For the patients with fatty liver and the healthy volunteers, the SWALI sequence showed no significant difference with CSE-MRI in FF quantification (P=0.53). In T1 quantification, comparable T1 values were obtained with the SWALI sequence and modified Look-Locker inversion recovery (MOLLI; P=0.10) in healthy volunteers, while the water T1 estimated by the SWALI sequence was significantly lower than the water-fat compound T1 estimated by MOLLI (P<0.001) in patients with fatty liver. In the reproducibility study, the intraclass correlation coefficients (ICCs) for the estimated FF and water T1 were 0.997 and 0.943, respectively. Water T1 of the patients with HCC calculated using the SWALI sequence showed a significant reduction after the contrast administration (P<0.001). Conclusions: Free-breathing water-fat separation and T1 mapping of the whole liver with 2.5 mm isotropic spatial resolution were achieved simultaneously using the SWALI sequence in a 5-min scan.

Scar-Degrading Endothelial Cells as a Treatment for Advanced Liver Fibrosis.

Deposition of extracellular matrix (ECM) in the liver is an important feature of liver cirrhosis. Recovery from liver cirrhosis is physiologically challenging, partially due to the ECM in scar tissue showing resistance to cell-mediated degradation by secreted matrix metalloproteinases (MMPs). Here, a cell-mediated ECM-degradation screening system (CEDSS) in vitro is constructed for high-throughput searching for cells with tremendous degradation ability. ECM-degrading liver sinusoidal endothelial cells (dLSECs) are screened using CEDSS, which exhibit 17 times the ability to degrade collagen when compared to other cells. The degradation ability of dLSECs is mediated by the upregulation of MMP9. In particular, mRNA expression of MMP9 shows an 833-fold increase in dLSECs compared to normal endothelial cells (nLSECs), and MMP9 is regulated by transcription factor c-Fos. In vivo, single intrasplenic injection of dLSECs alleviates advanced liver fibrosis in mice, while intraperitoneal administration of liver-targeting peptide-modified dLSECs shows enhanced fibrosis-targeting effects. Degradative human umbilical vein endothelial cells (dHUVECs) prove their enhanced potential of clinical translation. Together, these results highlight the potential of ECM-degrading endothelial cells in alleviating advanced liver fibrosis, thus providing remarkable insights in the development of ECM-targeting therapeutics.

Patterns of Caudate Lobe Invasion of Hilar Cholangiocarcinoma: A Panoramic Histologic Study of Liver.

BACKGROUND: At present, caudate lobectomy (CL) in hilar cholangiocarcinoma (HCCA) was controversial. Our study was designed to investigate the features of caudate lobe invasion (CLI) by whole-mount histologic large sections (WHLS). METHODS: A total of 46 HCCA patients underwent hemihepatectomy or trisectionectomy combined with CL were included. Serial WHLS (120 mm × 100 mm) were collected, and the relationship between caudate lobe and tumor was retained to determine the incidence of CLI. Hematoxylin and eosin (HE) and immunohistochemical (IHC) staining were completed to further explore the pathway of CLI. RESULTS: The whole region of the Glisson system in caudate lobe and hilar area can be clearly displayed by WHLS, and 32 (32/46 69.6%) patients were identified with CLI. There were three different pathways of CLI with panoramic IHC staining. The most common pathway is through the fibrous connective tissue along Glisson system (20/32 62.5%, without carcinoma in bile ducts). The Bismuth type, tumor size, vascular invasion, pathological type, and hepatic invasion were related to the CLI (p < 0.05). CONCLUSIONS: The incidence and distribution of CLI provided histologic evidence for CL in HCCA. Based on the invasion pathway, it is necessary to assess the fibrous connective tissue in Glisson system of caudate lobe in pathological research and practice.

Intraductal papillary neoplasm of intrahepatic bile ducts complicated by chronic disseminated intravascular coagulation and thrombosis: A case report.

RATIONALE: Intraductal papillary neoplasm of the bile ducts (IPNB) is a relatively rare tumor that is clinically characterized by digestive symptoms. The concurrent occurrence of chronic disseminated intravascular coagulation (DIC) with thrombosis is an extremely rare combination, reported in patients with IPNB. The clinical features of chronic DIC include microangiopathic hemolytic anemia, thrombocytopenia, and hypofibrinogenemia. Here, we report the case of a mucin-producing IPNB patient with hematological abnormalities. PATIENT CONCERNS: A 58-year-old male patient suffered from abdominal distension for more than 2 months with obstructive jaundice appearance. Abdominal contrast-enhanced computed tomography and magnetic resonance cholangiopancreatography showed a neoplasm in the right hepatic lobe. Multiple intravascular fillings were found in the inferior vena cava, pulmonary artery, and right atrium. Anemia and hypofibrinogenemia were discovered through routine laboratory tests. The count of platelets began to decline 25 days after admission, while 1 month after hospitalization, the patient developed abdominal pain, fever, and shock. DIAGNOSIS: Pathological examination demonstrated IPNB with a part of high-grade intraepithelial neoplasia. Cardiac and inferior vena cava emboli were diagnosed as thrombi without neoplastic cells. Immunohistochemically, tumor cells were positive for Vimentin (mesenchyme), CK7, CK19, MUC-1, MUC-5AC, MUC-6, S-100p (focal), Ki-67 (12%), and negative for Inhibin-α, ER, CK20, CEA, and MUC-2. Additionally, immunohistochemistry indicated that IPNB was a mucus-secretion gastric type. The laboratory tests confirmed the presence of chronic DIC. INTERVENTIONS: The patient was given anticoagulant therapy before hepatectomy and right atrium thrombectomy was performed under cardiopulmonary bypass. OUTCOMES: After anticoagulant therapy, the levels of hemoglobin, platelet, and fibrinogen of the patient returned to normal. Hepatectomy and thrombus removal was successfully performed. Then, the patient was discharged 12 days after the operation. After 12 months of follow-up, the patient recovered well without any hematologic abnormalities and no signs of tumor recurrence were observed. LESSONS: IPNB may cause hematological complications, which can be easily misdiagnosed. It is essential to pay particular attention to the hematological abnormalities of patients with IPNB. Early detection and differential diagnosis of chronic DIC and thrombosis are necessary. We note that anticoagulant therapy coupled with surgery is an effective strategy to treat these complications.

Reconstruction of the middle hepatic vein using a vein graft from the resected portion of the liver.

BACKGROUND: The middle hepatic veins are often infiltrated by intrahepatic cholangiocarcinoma. Reconstruction of the hepatic vein plays a critical role in preserving more of the residual liver volume and reducing the risk of postoperative liver failure in extreme hepatectomy. We here report a novel way to reconstruct middle hepatic vein by using vessel grafts from wasted liver. CASE PRESENTATION: Case 1: A 64-year-old man was diagnosed with intrahepatic cholangiocarcinoma. The bifurcation and left branch of the portal vein were stenosed, and the root of the middle hepatic vein was infiltrated by the tumor. An extended left hepatectomy was performed, the portal vein was resected and reconstructed, and the middle hepatic vein was reconstructed by anastomosing the proximal left hepatic vein to the distal middle hepatic vein. Case 2: A 69-year-old woman was diagnosed with intrahepatic cholangiocarcinoma. The tumor was located in the left lobe of the liver and the left and middle hepatic veins were infiltrated by the tumor. An extended left hepatectomy was performed, and the left portal vein was used as a vein graft to reconstruct the middle hepatic vein. Both of the two patients' postoperative ultrasound showed vessel graft patency. CONCLUSION: Using a vein graft from the resected portion of the liver to reconstruct the middle hepatic vein was a useful technique and showed good result.

The effect of preoperative biliary stents on outcomes after pancreaticoduodenectomy: A meta-analysis.

BACKGROUND: Whether biliary drainage should be performed before surgery in jaundiced patients is a topic of debate. Published studies on the effect of preoperative biliary drainage show great discrepancies in their conclusions, and the use of different drainage methods is an important factor. The aim of the present study was to investigate the effect of preoperative biliary stents (PBS) on postoperative outcomes in patients following pancreaticoduodenectomy (PD). METHODS: MEDLINE, EMBASE, Science Citation Index Expanded, and the Cochrane database were searched up to October 2019 to identify all published articles related to the topic. A meta-analysis was performed to compare postoperative outcomes in patients with and without PBS. Quality assessment and data extraction from included studies were performed by 2 independent authors. Statistical analysis was performed using RevMan 5.2 software. RESULTS: Twenty-seven studies involving 10,445 patients were included in the analysis. Biliary drainage was performed in 5769 patients (PBS group), and the remaining 4676 patients underwent PD directly (direct surgery [DS] group). Overall mortality, severe complications, abdominal hemorrhage, bile leakage, intra-abdominal abscess, and pancreatic fistula were not significantly different between the PBS and DS groups. However, overall morbidity, delayed gastric emptying, and wound infection were significantly higher in the PBS group compared to the DS group. Subgroup analysis indicated that the adverse effect of PBS on postoperative complications was more evident with increased stent proportion. CONCLUSIONS: Preoperative biliary stenting increases overall morbidity, delayed gastric emptying, and wound infection rates in patients following PD. Thus, preoperative biliary drainage via stent placement should be avoided in patients waiting for PD.

The value of 99mTc-labeled galactosyl human serum albumin single-photon emission computerized tomography/computed tomography on regional liver function assessment and posthepatectomy failure prediction in patients with hilar cholangiocarcinoma.

BACKGROUND: The aim was to evaluate the value of Tc-labeled galactosyl human serum albumin (Tc-GSA) with single-photon emission computerized tomography (SPECT) in the preoperative assessment of regional liver function and prediction of posthepatectomy liver failure (PHLF) in patients with hilar cholangiocarcinoma (hCCA). METHODS: Patients with hCCA who underwent Tc-GSA SPECT/computed tomography (CT) before hepatectomy were included. The liver functional parameters of functional liver density (FLD) and predictive residual index (PRI) were calculated based on Tc-GSA SPECT/CT. PHLF was defined according to the International Study Group of Liver Surgery criteria. Univariate and multivariate analyses were used to analyze the risk factors for PHLF. The prediction of PHLF was calculated using receiver operating characteristic curve. RESULTS: A total of 34 patients were included, 23 of whom underwent preoperative biliary drainage. FLD was significantly higher in patients with drained lobes than that in patients with undrained lobes (0.615 ± 0.190 versus 0.500 ± 0.211, P < 0.05). Sixteen patients suffered PHLF. The ratio of future remnant to total morphological liver volume, future remnant FLD, and PRI differed significantly in patients with and without PHLF according to univariate analysis. PRI was identified as the only independent factor for prediction of PHLF according to multivariate analysis. With a PRI of 0.78, it was possible to predict PHLF with a sensitivity of 83% and a specificity of 93%. CONCLUSIONS: Tc-GSA SPECT/CT can accurately assess regional liver function and is better able to predict PHLF than conventional methods in patients with hCCA.

Targeted-gene sequencing of an undifferentiated gallbladder carcinoma: a case report.

BACKGROUND: Undifferentiated carcinomas of the gallbladder are extremely rare. Most undifferentiated carcinomas are accompanied by adjacent foci of other conventional carcinomas, and a transition zone is shared between them. However, genetic alterations of undifferentiated gallbladder carcinoma and the similarities or differences between the undifferentiated carcinoma and the foci conventional carcinoma are unknown. CASE PRESENTATION: Herein, we report a case of undifferentiated gallbladder carcinoma with osteoclast-like giant cells with invasion into the liver, duodenum, and stomach in a 56-year-old man. The tumor was microscopically formed from the tubular adenocarcinoma (< 5% of the entire tumor), the undifferentiated carcinoma, and a transition zone between them. Four somatic mutations (TP53, TERT, ARID2, and CDH1), three amplifications (CCND1, FGF19, and MET), and a tumor mutation burden (TMB) of 3.45 muts/Mb were detected in the undifferentiated component using targeted gene sequencing, whereas 102 somatic mutations (including TP53, TERT, ARID2, and CDH1), one amplification (CCND1), and a higher TMB of 87.07 muts/Mb were detected in the tubular component. This patient died of tumor recurrence 2 months after the surgery. CONCLUSIONS: The undifferentiated gallbladder carcinoma had its unique molecular alterations. The similarities in the genetic alterations of the undifferentiated carcinoma and adenocarcinoma provide evidence of a common origin at the genetic level. The occurrence of an undifferentiated carcinoma may be due to heterogeneity-associated branched evolution from the tubular adenocarcinoma.

The Use of Three-Dimensional Printing Model in the Training of Choledochoscopy Techniques.

AIM: To evaluate the application value of a three-dimensional (3D) printing model in the training of choledochoscopy techniques. MATERIALS AND METHODS: Imaging data from two patients with biliary dilatation were used to produce two 3D reconstruction models which were subsequently constructed into 3D printing models (No. 1 and No. 2). Four hepatobiliary surgeons evaluated the anatomical accuracy and academic teaching value of the printed models. Twenty resident trainees with no prior experience in any kind of endoscopic techniques were randomly and symmetrically divided into two groups. The training group (A) used the 3D model No. 1 in the learning of biliary tract anatomy and practice techniques of choledochoscopy. The control group (B) got the virtual 3D image of the same model on computer for learning. After 4 weeks, the model No. 2 was used to reassess the trainees' subjective and objective progress in anatomy familiarity and choledochoscopy manipulations. RESULTS: All consulted surgeons agreed that the 3D models realistically reproduced the anatomy of the biliary system. All trainees in group A agreed or strongly agreed that the 3D models provided good anatomical realism, enhanced their experience in the training of choledochoscopy techniques, and aided in their learning of biliary anatomy. With the practice went on, they increased the accuracy and showed a reduction in operation time on the model No. 1. During final examination with model No. 2, the rate of correct anatomical structure identification in training group was significantly higher than group B (p < 0.05). CONCLUSION: The 3D printed biliary tract model is an excellent teaching tool in the training of choledochoscopy techniques. The 3D model is anatomically realistic and can improve the trainee's anatomical knowledge and endoscopic skills.

Choledochoscopic Examination of a 3-Dimensional Printing Model Using Augmented Reality Techniques: A Preliminary Proof of Concept Study.

BACKGROUND: We applied augmented reality (AR) techniques to flexible choledochoscopy examinations. METHODS: Enhanced computed tomography data of a patient with intrahepatic and extrahepatic biliary duct dilatation were collected to generate a hollow, 3-dimensional (3D) model of the biliary tree by 3D printing. The 3D printed model was placed in an opaque box. An electromagnetic (EM) sensor was internally installed in the choledochoscope instrument channel for tracking its movements through the passages of the 3D printed model, and an AR navigation platform was built using image overlay display. The porta hepatis was used as the reference marker with rigid image registration. The trajectories of the choledochoscope and the EM sensor were observed and recorded using the operator interface of the choledochoscope. RESULTS: Training choledochoscopy was performed on the 3D printed model. The choledochoscope was guided into the left and right hepatic ducts, the right anterior hepatic duct, the bile ducts of segment 8, the hepatic duct in subsegment 8, the right posterior hepatic duct, and the left and the right bile ducts of the caudate lobe. Although stability in tracking was less than ideal, the virtual choledochoscope images and EM sensor tracking were effective for navigation. CONCLUSIONS: AR techniques can be used to assist navigation in choledochoscopy examinations in bile duct models. Further research is needed to determine its benefits in clinical settings.

Augmented reality navigation in open surgery for hilar cholangiocarcinoma resection with hemihepatectomy using video-based in situ three-dimensional anatomical modeling: A case report.

RATIONALE: Patients who undergo hilar cholangiocarcinoma (HCAC) resection with concomitant hepatectomy have a high risk of postoperative morbidity and mortality due to surgical trauma to the hepatic and biliary vasculature. PATIENT CONCERNS: A 58-year-old Chinese man with yellowing skin and sclera, abdominal distension, pruritus, and anorexia for approximately 3 weeks. DIAGNOSES: Magnetic resonance cholangiopancreatography and enhanced computed tomography (CT) scanning revealed a mass over the biliary tree at the porta hepatis, which diagnosed to be s a hilar cholangiocarcinoma. INTERVENTION: Three-dimensional (3D) images of the patient's hepatic and biliary structures were reconstructed preoperatively from CT data, and the 3D images were used for preoperative planning and augmented reality (AR)-assisted intraoperative navigation during open HCAC resection with hemihepatectomy. A 3D-printed model of the patient's biliary structures was also used intraoperatively as a visual reference. OUTCOMES: No serious postoperative complications occurred, and the patient was tumor-free at the 9-month follow-up examination based on CT results. LESSONS: AR-assisted preoperative planning and intraoperative navigation might be beneficial in other patients with HCAC patients to reduce postoperative complications and ensure disease-free survival. In our postoperative analysis, we also found that, when the3D images were superimposed 3D-printed model using a see-through integral video graphy display device, our senses of depth perception and motion parallax were improved, compared with that which we had experienced intraoperatively using the videobased AR display system.