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Background: The Critical View of Safety (CVS) was proposed in 1995 to prevent bile duct injury during laparoscopic cholecystectomy (LC). The achievement of CVS was evaluated subjectively. This study aimed to develop an artificial intelligence (AI) system to evaluate CVS scores in LC., Materials and Methods: AI software was developed to evaluate the achievement of CVS using an algorithm for image classification based on a deep convolutional neural network. Short clips of hepatocystic triangle dissection were converted from 72 LC videos, and 23,793 images were labeled for training data. The learning models were examined using metrics commonly used in machine learning., Results: The mean values of precision, recall, F-measure, specificity, and overall accuracy for all the criteria of the best model were 0.971, 0.737, 0.832, 0.966, and 0.834, respectively. It took approximately 6 fps to obtain scores for a single image., Conclusions: Using the AI system, we successfully evaluated the achievement of the CVS criteria using still images and videos of hepatocystic triangle dissection in LC. This encourages surgeons to be aware of CVS and is expected to improve surgical safety., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Attention to anatomical landmarks in the appropriate surgical phase is important to prevent bile duct injury (BDI) during laparoscopic cholecystectomy (LC). Therefore, we created a cross-AI system that works with two different AI algorithms simultaneously, landmark detection and phase recognition. We assessed whether landmark detection was activated in the appropriate phase by phase recognition during LC and the potential contribution of the cross-AI system in preventing BDI through a clinical feasibility study (J-SUMMIT-C-02)., Methods: A prototype was designed to display landmarks during the preparation phase and Calot's triangle dissection. A prospective clinical feasibility study using the cross-AI system was performed in 20 LC cases. The primary endpoint of this study was the appropriateness of the detection timing of landmarks, which was assessed by an external evaluation committee (EEC). The secondary endpoint was the correctness of landmark detection and the contribution of cross-AI in preventing BDI, which were assessed based on the annotation and 4-point rubric questionnaire., Results: Cross-AI-detected landmarks in 92% of the phases where the EEC considered landmarks necessary. In the questionnaire, each landmark detected by AI had high accuracy, especially the landmarks of the common bile duct and cystic duct, which were assessed at 3.78 and 3.67, respectively. In addition, the contribution to preventing BDI was relatively high at 3.65., Conclusions: The cross-AI system provided landmark detection at appropriate situations. The surgeons who previewed the model suggested that the landmark information provided by the cross-AI system may be effective in preventing BDI. Therefore, it is suggested that our system could help prevent BDI in practice. Trial registration University Hospital Medical Information Network Research Center Clinical Trial Registration System (UMIN000045731)., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: We have implemented Smart Endoscopic Surgery (SES), a surgical system that uses artificial intelligence (AI) to detect the anatomical landmarks that expert surgeons base on to perform certain surgical maneuvers. No report has verified the use of AI-based support systems for surgery in clinical practice, and no evaluation method has been established. To evaluate the detection performance of SES, we have developed and established a new evaluation method by conducting a clinical feasibility trial., Methods: A single-center prospective clinical feasibility trial was conducted on 10 cases of LC performed at Oita University hospital. Subsequently, an external evaluation committee (EEC) evaluated the AI detection accuracy for each landmark using five-grade rubric evaluation and DICE coefficient. We defined LM-CBD as the expert surgeon's "judge" of the cystic bile duct in endoscopic images., Results: The average detection accuracy on the rubric by the EEC was 4.2 ± 0.8 for the LM-CBD. The DICE coefficient between the AI detection area of the LM-CBD and the EEC members' evaluation was similar to the mean value of the DICE coefficient between the EEC members. The DICE coefficient was high score for the case that was highly evaluated by the EEC on a five-grade scale., Conclusion: This is the first feasible clinical trial of an AI system designed for intraoperative use and to evaluate the AI system using an EEC. In the future, this concept of evaluation for the AI system would contribute to the development of new AI navigation systems for surgery., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Endoscopic tumor resection and intestinal defect repair are technically challenging leading to invasive surgery and colectomy performed for resection of benign polyps. In this study, we evaluated the use of an endoscopic overtube with bilateral tool channels for these procedures., Methods: Using a fresh porcine colorectum in a 3D ex vivo model, 3 cm lesions at the posterior wall of the transverse colon were removed by two different techniques: standard endoscopic submucosal dissection (ESD) technique (STD, n = 12) and ESD using the overtube with an endoscopic snare and grasper through the bilateral channels (OT, n = 12). Procedure times and the number of muscular injuries were evaluated. Using the same model, 5-10 mm full-thickness perforations within a 3 cm mucosal defect at the posterior wall of the transverse colon were closed by two different techniques: standard endoscopic closure technique (STD, n = 12) and endoscopic closure using the overtube with two graspers (OT, n = 12). The outcomes measured included bursting pressure and the number of endoscopic clips used for closure., Results: Endoscopic resection of lesions was performed by the OT group in a significantly shorter total procedure time (STD vs. OT = median 38.9 min vs. 17.3, p < 0.001) and with fewer muscular injuries (median 0 vs. 2, p = 0.002), compared with the STD group. After repair of intestinal defects, the OT group showed higher median bursting pressures (STD vs. OT = 11.2 mmHg vs. 57.1, p = 0.008) despite using fewer clips (median 13 vs. 10, p < 0.001)., Conclusion: This study demonstrates a novel traction technique with an endoscopic overtube using multiple instruments to remove lesions and repair intestinal defects in the colon more effectively. This endoscopic platform could provide a safe alternative to invasive surgical treatment., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Endoscopic submucosal dissection (ESD) is a challenging procedure for the removal of colorectal tumors, especially tumors located in the right colon. The use of traction could make this procedure technically easier and reduce procedure times and complication rates. In this study, we demonstrated the feasibility and utility of a traction technique utilizing an endoscopic snare through an overtube, a double-balloon endolumenal interventional platform (DEIP) in a porcine colorectal model., Methods: A total of 120 procedures were performed using three different techniques: standard ESD technique (STD), ESD with DEIP (DEIP alone), and ESD with DEIP and a snare (DEIP + Snare). The snare was passed inside the overtube and used as a grasper on the tissue to provide traction. Lesions 3 or 4 cm in diameter were removed with a 5 mm margin from the anterior and posterior walls of the proximal Transverse Colon, the Hepatic Flexure, and the posterior wall of the Cecum. The outcomes measured included procedure times and the number of muscularis propria injuries., Results: The DEIP + Snare group showed significantly shorter total procedure and submucosal dissection times for lesions in all locations (median 28.1 min (DEIP + Snare, n = 32) vs 39.8 (STD, n = 32) vs 39.7 (DEIP alone, n = 32); 7.5 min vs 25.3 vs 25.1) and had fewer muscularis propria injuries (median 0 [range 0-2] vs 2 [0-7] vs 1 [0-6]) than the two other groups. Larger lesions (4 cm) were successfully removed by regrasping the tissue in DEIP + Snare group, which showed significantly shorter total procedure time [31.4 min (DEIP + Snare, n = 8) vs 40.1 (STD, n = 8) vs 45.6 (DEIP alone, n = 8)] and submucosal dissection time (12.3 min vs 27.6 vs 29.1) than the two other groups., Conclusions: ESD traction technique with an endolumenal platform and snare enables faster removal of large polyps in the right colon with fewer injuries than standard methods of ESD., (© 2020. Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: To elucidate the relationships between mural nodules (MNs) and invasive components in patients with invasive intraductal papillary mucinous neoplasm (IPMN) on the basis of thin-section contrast-enhanced multidetector CT (CE-MDCT) and pathologic findings., Methods: This retrospective study included 28 patients with surgically confirmed invasive IPMN. Two radiologists independently evaluated the thin-section (1-mm section thickness, no overlap) triple-phase CE-MDCT images for MNs, invasive components, and the continuity between them using a five-point scale (confidence scores of 1-3 as negative, 4 and 5 as positive). Kappa statistic was used to evaluate interobserver agreement. The CE-MDCT findings were correlated with pathologic findings., Results: Interobserver agreement was good or excellent. MNs consisting of tumor cells were recognized in 12 (42.9%) of 28 patients with no discrepancy between the two radiologists. Invasive components were detected in 85.7% and 82.1% in the pancreatic parenchymal phase for radiologist 1 and 2, respectively, and recognized as hypoattenuating areas. Pathologic continuities between MNs and invasive components were confirmed in five (41.7%) of 12 patients with MNs and these were detected on CE-MDCT. When combined seven patients without continuities between MNs and invasive components and 16 patients without MNs, the invasive components pathologically derived from non-nodular low-height papillary epithelium in 23 (82.1%) of 28 patients., Conclusions: The invasive components derived more often from low-height papillary epithelium without MN appearance on CE-MDCT than from MN. Careful attention should be paid to the existence of an invasive component even in the absence of an enhancing MN.

Background: Iatrogenic inferior vena cava (IVC) injury is a rare but potentially life-threatening complication during laparoscopic surgery. This experimental study aimed to assess the hemostatic ability of a new device, double balloon-equipped central venous (DB-CV) catheter, for IVC injury., Methods: The DB-CV catheter comprises a triple-lumen sphincterotome combined with two dilating balloons having a diameter of 25 mm. The experimental procedures were performed in five pigs. The DB-CV catheter was inserted via the right femoral vein. For the IVC occlusion test, correct placement of the balloons was confirmed by indocyanine green fluorescence imaging, and hemodynamic data were recorded. For the IVC injury test, a 3- to 4-mm circumferential incision was created in IVC, and hemostasis was initiated using balloon inflation 5 s after the injury., Results: Hemodynamic changes were minimal, with a 20 mmHg reduction in the mean arterial pressure because of IVC occlusion. All bleeding from IVC injuries was successfully temporarily stopped by direct balloon compression, with a mean time to hemostasis of 69 s and mean blood loss of 32 ml. Subsequently, the positioning of IVC injuries between two balloons made it possible to suture the injured IVC., Conclusions: Balloon occlusion using the DB-CV catheter provides a rapid temporal hemostatic effect and can overcome the serious condition of massive hemorrhage from IVC injuries.

Background: Intrahepatic cholangiocarcinoma (IHCC) is a highly malignant neoplasm, but the prognostic factors of IHCC are not yet fully understood. The matrix metalloproteinases (MMPs) are known to be related to tumor viability. The aim of this study was to evaluate the prognostic significance of clinicopathological and immunohistochemical characteristics of resected IHCC., Patients and Methods: From 1996 to 2006, we surgically treated 35 patients with IHCC. Clinicopathological and immunohistochemical characteristics, including expression of MMPs, vascular endothelial growth factor, and epidermal growth factor receptor in the resected specimens, were investigated, and overall survival rates were evaluated with regard to the characteristics using univariate and multivariate analyses., Results: Univariate analysis revealed the significant prognostic factors to be preoperative serum CEA and CA19-9, intraoperative transfusion, tumor size, surgical margin, lymph node metastasis, invasion of portal and hepatic vein, intrahepatic metastasis, UICC stage, and expression of MMP-7. Subsequent multivariate analysis indicated that MMP-7 was an independent prognostic factor (hazard ratio (HR), 4.698; 95% confidence interval (CI), 0.057-0.866; P = 0.03) along with intrahepatic metastasis (HR, 5.694; 95% CI, 0.029-0.706; P = 0.017)., Conclusion: MMP-7 expression is associated with a poor prognosis in patients with resected IHCC.

A continuous flow-type hydrothermal reaction system, in which both temperature and pressure were rapidly and dynamically controlled, was constructed. It is called a real time high temperature and pressure reaction system (RT-HighTP). The RT-HighTP was hyphenated with liquid chromatograph (RT-HighTP-LC) to achieve prompt analysis of the reaction products. The RT-HighTP system produced stable pressure under the supercritical and subcritical phases (%RSD < 3%). The RT-HighTP-LC was able to change the hydrothermal condition rapidly. The hydrothermal products under four conditions were analyzed within 70 min. Further, the hydrothermal products of lignin was easily taken out using the sample collecting loop and analyzed by an external instrument of GC/MS.