Three-Dimensional Bio-Printed Tubular Tissue Using Dermal Fibroblast Cells as a New Tissue-Engineered Vascular Graft for Venous Replacement.

The current study was a preliminary evaluation of the feasibility and biologic features of three-dimensionally bio-printed tissue-engineered (3D bio-printed) vascular grafts comprising dermal fibroblast spheroids for venous replacement in rats and swine. The scaffold-free tubular tissue was made by the 3D bio-printer with normal human dermal fibroblasts. The tubular tissues were implanted into the infrarenal inferior vena cava of 4 male F344-rnu/rnu athymic nude rats and the short-term patency and histologic features were analyzed. A larger 3D bio-printed swine dermal fibroblast-derived prototype of tubular tissue was implanted into the right jugular vein of a swine and patency was evaluated at 4 weeks. The short-term patency rate was 100%. Immunohistochemistry analysis showed von Willebrand factor positivity on day 2, with more limited positivity observed on the luminal surface on day 5. Although the cross-sectional area of the wall differed significantly between preimplantation and days 2 and 5, suggesting swelling of the tubular tissue wall (both p < 0.01), the luminal diameter of the tubular tissues was not significantly altered during this period. The 3D bio-printed scaffold-free tubular tissues using human dermal or swine fibroblast spheroids may produce better tissue-engineered vascular grafts for venous replacement in rats or swine.

Resection and reconstruction of the largest abdominal vein system (the inferior vena cava, hepatic, and portal vein): a narrative review.

Background and Objective: As tumors invade major abdominal veins, surgical procedures are transformed from simple and basic to complicated and challenging. In this narrative review, we focus on what is currently known and not known regarding the technical aspects of major abdominal venous resection and its reconstruction, patency, and oncologic benefit in a cross-cutting perspective. Methods: A systematic literature search was performed in PubMed and Semantic Scholar from inception up to October 18, 2023. We reviewed 106 papers by title, abstract, and full text regarding resection or reconstruction of the inferior vena cava, hepatic vein confluence, portal vein (PV), and middle hepatic vein (MHV) tributaries in living donor liver transplantation (LDLT) in a cross-cutting perspective. Key Content and Findings: The oncologic benefit of aggressive hepatic vein resection with suitable reconstruction against adenocarcinoma remains unclear, and further studies are required to clarify this point. A superior mesenteric/PV resection is now a universal, indispensable, and effective procedure for pancreatic ductal adenocarcinoma. Although many case series using tailor-made autologous venous grafts have been reported, not only size mismatch but also additional surgical incisions and a longer operation time remain obstacles for venous reconstruction. The use of autologous alternative tissue remains only an alternative procedure because the patency rate of customized tubular conduit type to interpose or replace the resected vein is not known. Unlike arterial replacement, venous replacement using synthetic vascular grafts is still rarely reported and there are several inherent limitations except for reconstruction of tributaries of MHV in LDLT. Conclusions: Various approaches to abdominal vein resection and replacement or reconstruction are technically feasible with satisfactory results. Synthetic vascular grafts may be appropriate but have a certain rate of complications.

Endoscopic ultrasound-guided fine needle biopsy diagnosis of circumferentially extraluminal mucosa-associated lymphoid tissue lymphoma in the transverse colon: a case report.

A 61-year-old man present to us with continued abdominal pain without abdominal tenderness for 1 month. Blood testing showed elevated biliary enzymes and inflammation. Contrast-enhanced computed tomography (CT) revealed thickening of the transverse colon with relatively strong enhancement but no bile duct dilatation. Colonoscopy revealed localized edema and granular mucosa in the transverse colon. Fluoroscopic endoscopy exhibited the absence of haustra. Multiple biopsies were performed, but differentiation between mild inflammation and mucosa-associated lymphoid tissue (MALT) lymphoma was inconclusive. To establish a definitive diagnosis, transgastric endoscopic ultrasound-guided fine needle biopsy of the hypoechoic mass was performed. Histopathological analysis exhibited the proliferation of small-sized lymphocytes. Fluorescence in situ hybridization revealed the characteristic API2-MALT1 translocation of MALT lymphoma. We performed liver biopsy to investigate biliary enzyme elevation. Histopathology confirmed lymphocytic infiltration within Glisson's capsule. Immunohistochemistry showed positive for CD20 and negative for CD3 and CD5, signifying the infiltration of MALT lymphoma in the liver. Based on these findings, we diagnosed MALT lymphoma, Lugano classification Stage IV. We performed bendamustine-rituximab (BR)-combined therapy. After six courses of BR-combined therapy, colonoscopy revealed improvement in the lead pipe sign and CT revealed disappearance of the mass.

Efficacy of a Novel Tapered Contrast Catheter for Endoscopic Ultrasound-Guided Hepaticogastrostomy: A Multicenter Study.

Background: Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is an alternative for failed endoscopic retrograde cholangiopancreatography (ERCP), with current success rates of 65-84% considered suboptimal. A novel ERCP catheter (SHOREN, Kaneka Corporation, Osaka, Japan) with a tapered 3.3-French tip may facilitate smoother insertion, potentially improving outcomes. Methods: This retrospective analysis encompassed EUS-HGS procedures conducted from January 2021 to August 2023 at four institutions. The aim of this study was to compare the performance of conventional and novel ERCP contrast catheters regarding the success rate of single-attempt catheter insertion, failure rates, technical success rates, and incidence of adverse events. Results: The study included 48 patients; 26 underwent EUS-HGS using conventional catheters and 22 with the novel catheter. The novel catheter achieved higher success rates in single-attempt insertions (96.5% vs. 80.8%) and lower failure rates (4.6% vs. 7.7%). The occurrence of bile peritonitis was comparable between the two groups. Conclusions: The novel ERCP contrast catheter with a tapered tip appears to contribute to successful catheter insertion and is useful for EUS-HGS.

Thick silk fibroin vascular graft: A promising tissue-engineered scaffold material for abdominal vein grafts in middle-sized mammals.

Abdominal vein replacement with synthetic tissue-engineered vascular grafts constructed from silk-based scaffold material has not been reported in middle-sized mammals. Fourteen canines that underwent caudal vena cava replacement with a silk fibroin (SF) vascular graft (15 mm long and 8 mm diameter) prepared with natural silk biocompatible thread were allocated to two groups, thin and thick SF groups, based on the graft wall thickness. The short-term patency rate and histologic reactions were compared. The patency rate at 2 weeks after replacement in the thin and thick SF groups was 50% and 88%, respectively (p = 0.04). CD31-positive endothelial cells covered the luminal surface of both groups at 4 weeks. The elastic modulus of the thick SF graft was significantly better than that of the thin SF graft (0.0210 and 0.0007 N/m2, p < 0.01). Roundness of thick SF groups (o = 0.8 mm) was better than thin SF (o = 2.0 mm). There was significant difference between the groups (p = 0.01). SF vascular grafts are a promising tissue-engineered scaffold material for abdominal venous system replacement in middle-sized mammals, with thick-walled grafts being superior to thin-walled grafts.

Incidental detection of upper gastrointestinal epithelial neoplasia by screening endoscopy prior to endoscopic ultrasonography in patients with pancreaticobiliary disease.

BACKGROUND: Screening esophagogastroduodenoscopy plays an important role in the early detection of upper gastrointestinal cancer. To provide more opportunities for patients with pancreaticobiliary disease to undergo this screening, we have performed esophagogastroduodenoscopy prior to endoscopic ultrasonography. However, the usefulness of this protocol is not elucidated. This study aimed to investigate the utility of screening esophagogastroduodenoscopy in this protocol in the detection of upper gastrointestinal epithelial neoplasms. METHODS: The outcomes of screening esophagogastroduodenoscopy performed prior to endoscopic ultrasonography in patients with pancreaticobiliary disease at our hospital between April 2020 and September 2022 were investigated. A logistic regression model was used to identify factors affecting the detection of epithelial neoplasms. Additionally, we compared the detection rate of gastric epithelial neoplasms between screening esophagogastroduodenoscopy performed prior to endoscopic ultrasonography and that performed at our medical checkup center. RESULTS: A total of 615 screening esophagogastroduodenoscopies prior to endoscopic ultrasonography were performed, and 12 (2.0%) epithelial neoplasms were detected, including esophageal lesions (n = 2) and gastric lesions (n = 10). Of these lesions, 75% (9/12) underwent curative endoscopic resection. A multivariate analysis showed that open-type gastric mucosal atrophy (odds ratio, 7.7; 95% confidence interval, 1.5-38.4; p = 0.01) and the use of magnification endoscopy (odds ratio, 7.3; 95% confidence interval, 1.9-27.9; p < 0.01) independently affected the detection of epithelial neoplasms. The detection rate of gastric epithelial neoplasms was significantly higher using this protocol than that in our medical checkup center (1.6% versus 0.2%, p < 0.01). CONCLUSIONS: A protocol of screening esophagogastroduodenoscopy prior to endoscopic ultrasonography may be recommended because epithelial neoplasms could be detected at a non-negligible rate.

Metallic Stents for Hepatic Venous Outflow Obstruction After Living-Donor Liver Transplantation and their Therapeutic Effects.

BACKGROUND: Living-donor liver transplantation (LDLT) is established as a standard therapy for end-stage liver disease; however, vessel reconstruction is more demanding due to the short length and small size of the available structures compared with deceased-donor whole liver transplantation. Interventional radiology (IR) has become the first-line treatment for vascular complications after LDLT. Hepatic venous outflow obstruction (HVOO) is a life-threatening complication after LDLT. The aim of this study of 592 adult-to-adult LDLT cases was to investigate the safety and efficacy of stent implantation for HVOO after LDLT. METHODS: Records of patients who developed HVOO requiring any treatment were collected with special reference to the metallic stent implantation. There were 232 left-side grafts and 360 right-side grafts. Sixteen cases developed HVOO after LDLT with an incidence rate of 2.7%, 5 with a left liver graft (2%), and 11 with a right-side graft (3%). The IR was attempted for 14 cases; among those, 8 cases were treated by stent implantation. RESULTS: The technical success rate of the initial stent implantation was 100%. The pressure gradient at the stenotic site significantly improved from 12.2 (range, 10.9-20.4 cm H2O) to 3.9 cm H2O (range, 1.4-8.2 cm H2O; P = .03). The volume of the congested graft liver decreased significantly from 1448 (range, 788-2170 mL) to 1265 mL (range, 748-1665 mL; P = .01), and the serum albumin level improved significantly from 3.3 (range, 1.7-3.7 g/dL) to 3.7 g/dL (range, 2.9-4.1 g/dL; P = .02). No procedure-related complication was noted, and the long-term stent patency was 100%. CONCLUSION: Metallic stent implantation for stenotic venous anastomosis after LDLT is a safe and effective treatment.

The Effect of Renin-Angiotensin System Inhibitors in Patients Undergoing Pancreatic Cancer Resection.

OBJECTIVES: The local renin-angiotensin system promotes angiogenesis and proliferation via vascular endothelial growth factor or epidermal growth factor receptor expression. In this study, we aimed to evaluate the impact of angiotensin system inhibitors (ASIs) on long-term outcomes in patients undergoing surgical resection of pancreatic ductal adenocarcinoma (PDAC). METHODS: A single institutional retrospective analysis was performed using the medical records of patients who underwent pancreatic resection with curative intent for PDAC between January 2005 and December 2018. Patient characteristics and surgical outcomes were compared between patients taking ASIs and those who are not. RESULTS: A total of 272 patients were included in the study and classified into the ASI group (n = 121) and the non-ASI group (n = 151). The median overall survival times in the ASI group and non-ASI group were 38.0 and 34.0 months ( P = 0.250), and the median recurrence-free survival times were 24.0 and 15.0 months ( P = 0.025), respectively. Multivariate analysis for recurrence-free survival identified the use of ASIs ( P = 0.020), CA19-9 level >500 IU/L ( P = 0.010), positive lymph node metastasis ( P < 0.001), and no adjuvant chemotherapy ( P < 0.001) as independent prognostic factors. CONCLUSIONS: The use of ASI may improve long-term outcomes after surgery for PDAC.

Effect of Smoke Evacuator on Reduction of Volatile Organic Compounds and Particles in Surgical Smoke: A Randomized Controlled Trial.

BACKGROUND: Surgical smoke is an occupational health problem and is increasingly recognized as a potential source of virus transmission. Dedicated smoke evacuators are used to protect against surgical smoke exposure. We tested the hypothesis that using smoke evacuators would reduce volatile organic compounds and the number of particles in surgical smoke during the laparotomy procedure. STUDY DESIGN: A randomized, double-blind clinical trial was conducted in patients undergoing laparotomy from June 11, 2021, to March 30, 2022, to compare the effectiveness of smoke evacuators with a control (registration, UMIN000044250). The primary outcome was a change in the acetaldehyde level. Secondary outcomes were changes in the formaldehyde level and particle count assessed by the particle size of 0.3, 0.5, 1.0, and 5.0 nm. RESULTS: A total of 42 patients were randomized and assessed (smoke evacuator group, n = 22 vs control group, n = 20). The acetaldehyde level was significantly lower in the smoke evacuator group than in the control group: mean (95% CI), 10.6 (3.7 to 17.5) vs 47.2 (19.9 to 74.5) µg/m 3 , p < 0.001. Similarly, the formaldehyde level was 72.2% lower in the smoke evacuator group than in the control group. Particle counts by each particle size category were 80% to 95% lower in the smoke evacuator group than in the control group (all, p < 0.001). CONCLUSIONS: Dedicated smoke evacuators reduced the level of acetaldehyde and formaldehyde, and the number of particles in surgical smoke, minimizing the potential exposure to volatile organic compounds and particle matters during surgery.

Evaluation of pancreatic chymotrypsin activity for on-site prediction of clinically relevant postoperative pancreatic fistula.

OBJECTIVES: Although the risk of complications due to postoperative pancreatic fistula (POPF) have been evaluated based on the amylase level in drained ascitic fluid, this method has much room for improvement regarding diagnostic accuracy and facility of the measurement. This study aimed to investigate the clinical value of measuring pancreatic chymotrypsin activity for rapid and accurate prediction of POPF after pancreaticoduodenectomy. METHODS: In 52 consecutive patients undergoing pancreaticoduodenectomy, the chymotrypsin activity in pancreatic juice was measured by calculating the increase in fluorescence intensity during the first 5 min after activation with an enzyme-activatable fluorophore. The predictive value for clinically relevant POPF (CR-POPF) was compared between this technique and the conventional method based on the amylase level. RESULTS: According to receiver operating characteristic analyses, pancreatic chymotrypsin activity on postoperative day (POD) 3 measured with a multiplate reader had the highest predictive value for CR-POPF (area under the curve [AUC], 0.752; P < 0.001), yielding 77.8 % sensitivity and 68.8 % specificity. The AUC and sensitivity/specificity of the amylase level in ascitic fluid on POD 3 were 0.695 (P = 0.053) and 77.8 %/41.2 %, respectively. Multivariable analysis identified high pancreatic chymotrypsin activity on POD 3 as an independent risk factor for CR-POPF. Measurement of pancreatic chymotrypsin activity with a prototype portable fluorescence photometer could significantly predict CR-POPF (AUC, 0.731; P = 0.010). CONCLUSION: Measurement of pancreatic chymotrypsin activity enabled accurate and rapid prediction of CR-POPF after pancreaticoduodenectomy. This can help surgeons to implement appropriate drain management at the patient's bedside without delay.

A data-informed timeline for hospital discharge with a reasonably low risk of unplanned readmission after open and minimally invasive liver resections.

BACKGROUND: Postoperative complications following liver resection remain high, ranging from 20% to 50%. Patients are hospitalized for a certain period of time following liver resection because of the risk of postoperative complications. We hypothesized that the risk of complications decreases with each complication-free postoperative day after open and minimally invasive liver resections and can be stratified using a recently reported three-level complexity classification. METHODS: Patients undergoing first liver resection without concomitant other organ resections between 2006 and 2019 were included. The three-level complexity classification was used to categorize liver resection procedures into grades I-III. We assessed the rate of cumulative postoperative complications from the time of liver resection to the time of post-hepatectomy complications (≥ Clavien-Dindo grade II). RESULTS: Of the 911 patients included, 200 underwent resection of grade I procedures, 185 underwent resection of grade II procedures, and 526 underwent resection of grade III procedures. The risks of post-hepatectomy complications changed over time and were stratified by surgical complexity. For patients at the time of liver resection, the estimated 30-day complication rate was 21.8% for open grade I resection, 26.7% for open grade II resection, 38.4% for open grade III resection, 8.6% for laparoscopic grade I resection, and 12.5% for laparoscopic grade II resection. For patients without complications at 7 days, the estimated 30-day complication rate decreased to 2.1% for open grade I, 9.2% for open grade II, 17.6% for open grade III, 1.3% for laparoscopic grade I, and 4.5% for laparascopic grade II. CONCLUSIONS: The post-hepatectomy complication risks were stratified by surgical complexity, liver resection approach, and the period without complication after liver resection.

Two-step artificial intelligence algorithm for liver segmentation automates anatomic virtual hepatectomy.

BACKGROUND: Anatomic virtual hepatectomy with precise liver segmentation for hemilivers, sectors, or Couinaud's segments using conventional three-dimensional simulation is not automated and artificial intelligence (AI)-based algorithms have not yet been applied. METHODS: Computed tomography data of 174 living-donor candidates for liver transplantation (training data) were used for developing a new two-step AI algorithm to automate liver segmentation that was validated in another 51 donors (validation data). The Pure-AI (no human intervention) and ground truth (GT, full human intervention) data groups were compared. RESULTS: In the Pure-AI group, the median Dice coefficients of the right and left hemilivers were highly similar, 0.95 and 0.92, respectively; sectors, posterior to lateral: 0.86-0.92, and Couinaud's segments 1-8: 0.71-0.89. Labeling of the first-order branch as hemiliver, right or left portal vein perfectly matched; 92.8% of the second-order (sectors); 91.6% of third-order (segments) matched between the Pure-AI and GT data. CONCLUSIONS: The two-step AI algorithm for liver segmentation automates anatomic virtual hepatectomy. The AI-based algorithm correctly divided all hemilivers, and more than 90% of the sectors and segments.

Probe-based confocal laser endomicroscopy for real-time evaluation of colorectal liver metastasis in resected surgical specimens.

Probe-based confocal laser endomicroscopy (pCLE) enables real-time examination of tissue structure. This study investigated pCLE with or without fluorescein sodium for the intraoperative diagnosis of colorectal liver metastasis (CLM) and detection of surgical margins. Thirty-four specimens of CLM and adjacent noncancerous tissue were obtained from 21 patients and examined by pCLE between May 2017 and March 2018. Images were obtained both without and with fluorescein sodium applied to the cut surface and compared with hematoxylin and eosin-stained tissue. Fluorescence intensity (FI) was measured by luminance-analysis software. Without external fluorophores, pCLE visualized 91.2% of CLM tissues as an irregular structure with low autofluorescence and 90.5% of noncancerous liver tissues as a regular structure with high autofluorescence. The median FI was significantly lower in cancer than in benign tissue in patients without chemotherapy [70.4 (51.6-110) vs. 48.3 (39.0-59.4), p = 0.002] and with chemotherapy [67.9 (54.6-89.2) vs. 48.6 (28.8-82.1), p < 0.001]. The border was clearly visible; pCLE with fluorescein sodium clearly showed their morphologies. In summary, our study demonstrated real-time pCLE distinguished CLM and noncancerous tissue by differences in structure and FI regardless of prehepatectomy chemotherapy. Fluorescein spray facilitated clear visualization of differences in the morphology.

Conditional recurrence analysis of intrahepatic cholangiocarcinoma: Changes in recurrence rate and survival after recurrence resection by disease-free interval.

AIM: The prognosis of patients with resected intrahepatic cholangiocarcinoma (ICC) is still unsatisfactory, with a high recurrence rate. We aimed to evaluate risks of recurrence changing over time and the survival benefit of resection for recurrent ICC. METHODS: This study included patients who underwent hepatectomy for ICC during 1995-2020. Risk factors for recurrence-free survival (RFS) in patients undergoing initial resection and overall survival (OS) in patients who developed recurrence after initial resection were analyzed. Conditional cumulative incidence of recurrence was assessed. RESULTS: A total of 169 patients were included in the study and 114 patients (67.5%) developed recurrence. Cumulative analyses showed that the 5-year recurrence rate was 69.3% at the time of initial resection but decreased to 24.8% in patients free from recurrence at 2 years after initial resection and 2.6% in patients free from recurrence at 4 years. Re-resection was carried out in 26 (22.8%) of 114 patients who developed recurrence. Multivariable Cox proportional hazards model analysis indicated re-resection (hazard ratio [HR] 0.19; 95% confidence interval [CI] 0.11-0.40, p < 0.001), microvascular invasion (MVI) (HR 2.39; 95% CI 1.05-5.40, p = 0.037), and disease-free interval (months) (HR 0.97; 95% CI 0.95-1.00, p = 0.067) were significantly associated with longer OS after recurrence. CONCLUSIONS: Although the rate of recurrence remains high, conditional cumulative recurrence rate analysis showed that the rate of recurrence decreased by disease-free interval. Resection of recurrent ICC was associated with improved OS, particularly among patients with longer disease-free interval and absence of MVI after initial hepatectomy.

Gallbladder perforation following peroral cholangioscopy-guided lithotripsy: A case report.

Peroral cholangioscopy-guided lithotripsy is highly effective in clearing difficult bile duct stones. It can cause adverse events, such as cholangitis and pancreatitis; however, gallbladder perforation is extremely rare. Herein, we describe the case of a 77-year-old woman who developed gallbladder perforation following peroral cholangioscopy -guided lithotripsy. She was referred to our hospital to treat multiple large bile duct stones. She underwent peroral cholangioscopy-guided lithotripsy because of conventional lithotripsy failure. After a cholangioscope was advanced into the bile duct, saline irrigation was used for visualization. Electronic hydraulic lithotripsy was performed, but it took time for fragmentation because the calculus was hard. The 2-h endoscopic procedure did not completely remove the stone, and treatment was discontinued after placing a biliary plastic stent and nasobiliary tube. After the endoscopic procedure, she started experiencing right hypochondrial pain, which worsened the next day. Computed tomography showed a gallbladder wall defect in the gallbladder fundus with pericholecystic fluid. She was diagnosed with gallbladder perforation and underwent emergency surgery. A perforation site was found at the gallbladder fundus. Open cholecystectomy, choledochotomy, and extraction of residual bile duct stones were performed. The patient was discharged 9 days post-surgery without any complications. The saline irrigation used for visualization may have caused a surge in intra-gallbladder pressure, resulting in gallbladder perforation. Therefore, endoscopists may need to conserve irrigation water during peroral cholangioscopy-guided lithotripsy.

Posthepatectomy but not prehepatectomy chemotherapy was associated with a longer time to recurrence in patients with resectable colorectal liver metastases: Inverse probability of treatment weighting analysis.

BACKGROUND: Patients with resectable colorectal liver metastases (CLM) are treated with surgery alone, surgery and posthepatectomy chemotherapy, or prehepatectomy chemotherapy and surgery. The optimal approach in terms of survival is unclear. We compared survival in the three treatment groups using inverse probability of treatment weighting (IPTW) analysis. METHODS: Data from patients undergoing initial CLM resection in 2005-2018 were obtained from a prospectively maintained database. Our group treated resectable CLM with surgery alone but gradually adopted post- and prehepatectomy chemotherapy for patients with CLM number ≥5 after 2015. IPTW analysis was employed to adjust the characteristics of the three groups. RESULTS: Of the 439 patients meeting the inclusion criteria, 175 underwent surgery alone, 135 underwent surgery and posthepatectomy chemotherapy, and 129 underwent prehepatectomy chemotherapy and surgery. After the IPTW adjustment, the demographic and clinicopathological characteristics were well balanced. The IPTW analysis revealed that the recurrence-free survival was better in patients undergoing surgery and posthepatectomy chemotherapy than in patients undergoing surgery alone (median recurrence-free survival, 1.3 years vs 0.7 years; P = .018). Overall survival was not significantly different between the three treatment approaches. CONCLUSION: Posthepatectomy but not prehepatectomy chemotherapy prolongs the time to recurrence after curative-intent resection of CLM.

Interventional treatment for portal vein complications utilizing a hybrid operating room after liver transplantation.

BACKGROUND: Vascular complications after liver transplantation (LT) can be lethal and require immediate treatment to prevent graft failure. Nowadays, with interventional radiology (IR), approaches such as the percutaneous transhepatic (PTH) and transileocolic venous (TIC), have become major treatment options. We reviewed the safety and efficacy of a hybrid operating room (OR) for portal vein complications after LT. METHODS: Patients who underwent IR for post-LT vascular complications in the hybrid OR from May 2014 to May 2022 were enrolled. Patients who underwent post-LT IR in conventional angiography rooms were excluded. RESULTS: Nine patients developed portal vein complications; eight after living donor LT and one after deceased donor LT. Six patients had portal vein stenosis, two had portal vein thrombosis, and one had both. In the hybrid OR, PTH and TIC were used in five and three cases, respectively. The Rendezvous technique was used in one case. Angioplasty was performed in all patients. A stent was placed in four patients. The portal venous pressure gradient across the stenotic site significantly decreased after IR (P &= 0.031). The IR success rate in the hybrid OR was 100%. CONCLUSION: The hybrid OR enables us to accomplish IR for post-LT vascular complications safely and effectively.

New Diagnostic Modality Combining Mass Spectrometry and Machine Learning for the Discrimination of Malignant Intraductal Papillary Mucinous Neoplasms.

BACKGROUND: An intraductal papillary mucinous neoplasm (IPMN) is a pancreatic tumor with malignant potential. Although we anticipate a sensitive method to diagnose the malignant conversion of IPMN, an effective strategy has not yet been established. The combination of probe electrospray ionization-mass spectrometry (PESI-MS) and machine learning provides a promising solution for this purpose. METHODS: We prospectively analyzed 42 serum samples obtained from IPMN patients who underwent pancreatic resection between 2020 and 2021. Based on the postoperative pathological diagnosis, patients were classified into two groups: IPMN-low grade dysplasia (n = 17) and advanced-IPMN (n = 25). Serum samples were analyzed by PESI-MS, and the obtained mass spectral data were converted into continuous variables. These variables were used to discriminate advanced-IPMN from IPMN-low grade dysplasia by partial least square regression or support vector machine analysis. The areas under receiver operating characteristics curves were obtained to visualize the difference between the two groups. RESULTS: Partial least square regression successfully discriminated the two disease classes. From another standpoint, we selected 130 parameters from the entire dataset by PESI-MS, which were fed into the support vector machine. The diagnostic accuracy was 88.1%, and the area under the receiver operating characteristics curve was 0.924 by this method. Approximately 10 min were required to perform each method. CONCLUSION: PESI-MS combined with machine learning is an easy-to-use tool with the advantage of rapid on-site analysis. Here, we show the great potential of our system to diagnose the malignant conversion of IPMN, which would be a promising diagnostic tool in clinical settings.