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.

The Role of Frequent Screening or Diagnostic Testing of Serum Cryptococcal Antigen in Liver Transplant Recipients: A Descriptive Epidemiology.

Background: Cryptococcosis is a notable infectious complication of liver transplantation. Currently, there is no recommendation for screening serum cryptococcal antigen (CrAg) levels in solid organ transplant recipients. We aimed to explore the role of serum CrAg in liver transplant recipients at an institution where posttransplant serum CrAg has been widely tested. Methods: This retrospective study was conducted at a tertiary care center in Japan. All liver transplant recipients with serum CrAg measured either for screening or for diagnostic testing at least once after transplantation between April 2005 and March 2022 were included. For participants with either a positive CrAg test result or positive culture for Cryptococcus, we manually reviewed clinical manifestations, management, and prognosis from the medical records. Results: During the study period, 12 885 serum CrAg tests (median, 16 tests per patient) were performed in 468 liver transplant recipients. The 1-year posttransplant incidence of positive serum CrAg test results and culture-proven cryptococcosis was 1.9% (9/468) and 0.6% (3/468), respectively. No patient with persistently negative serum CrAg test results showed growth of Cryptococcus in culture. Four patients had clinical manifestations consistent with cryptococcosis, of whom 2 (50.0%) started antifungal therapy promptly based on a positive serum CrAg test result. In contrast, 5 patients had no clinical manifestations. Three of the 5 (60.0%) patients did not receive antifungal therapy and remained free of clinical manifestations. Conclusions: Serum CrAg test was more sensitive than culture among liver transplant recipients and prompted early diagnosis and antifungal therapy in symptomatic patients. However, serial screening of serum CrAg in asymptomatic patients may be of little value, with the potential for false-positive results.

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.

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.

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.

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.

Protocol of the RACB study: a multicenter, single-arm, prospective study to evaluate the efficacy of resection of initially unresectable hepatocellular carcinoma with atezolizumab combined with bevacizumab.

BACKGROUND: Although the standard therapy for advanced-stage hepatocellular carcinoma (HCC) is systemic chemotherapy, the combination of atezolizumab and bevacizumab (atezo + bev) with a high objective response rate may lead to conversion to resection in patients with initially unresectable HCC. This study aims to evaluate the efficacy of atezo + bev in achieving conversion surgery and prolonged progression-free survival (PFS) for initially unresectable HCC. METHODS: The RACB study is a prospective, single-arm, multicenter, phase II trial evaluating the efficacy of combination therapy with atezo + bev for conversion surgery in patients with technically and/or oncologically unresectable HCC. The main eligibility criteria are as follows: (1) unresectable HCC without a history of systemic chemotherapy, (2) at least one target lesion based on RECIST ver. 1.1, and (3) a Child‒Pugh score of 5-6. The definition of unresectable tumors in this study includes macroscopic vascular invasion and/or extrahepatic metastasis and massive distribution of intrahepatic tumors. Patients will be treated with atezolizumab (1200 mg/body weight) and bevacizumab (15 mg/kg) every 3 weeks. If the patient is considered resectable on radiological assessment 12 weeks after initial chemotherapy, the patient will be treated with atezolizumab monotherapy 3 weeks after combination chemotherapy followed by surgery 3 weeks after atezolizumab monotherapy. If the patient is considered unresectable, the patient will continue with atezo + bev and undergo a radiological assessment every 9 weeks until resectable or until disease progression. The primary endpoint is PFS, and the secondary endpoints are the overall response rate, overall survival, resection rate, curative resection rate, on-protocol resection rate, and ICG retention rate at 15 min after atezo + bev therapy. The assessments of safety and quality of life during the treatment course will also be evaluated. The number of patients has been set at 50 based on the threshold and the expected PFS rate at 6 months after enrollment of 40% and 60%, respectively, with a one-sided alpha error of 0.05 and power of 0.80. The enrollment and follow-up periods will be 2 and 1.5 years, respectively. DISCUSSION: This study will elucidate the efficacy of conversion surgery with atezo + bev for initially unresectable HCC. In addition, the conversion rate, safety and quality of life during the treatment course will also be demonstrated. TRIAL REGISTRATION: This study is registered in the Japan Registry of Clinical Trials (jRCTs051210148, January 7, 2022).

Lenvatinib recruits cytotoxic GZMK+CD8 T cells in hepatocellular carcinoma.

BACKGROUND: Lenvatinib was expected to enhance the effect of immune checkpoint inhibitors (ICIs) for unresectable HCC; however, their combination therapy failed to show the synergy in the phase III clinical trial. METHODS: To elucidate lenvatinib-induced molecular modulation, we performed bulk RNA-sequencing and digital spatial profiling of 5 surgically resected human HCC specimens after lenvatinib treatment and 10 matched controls without any preceding therapy. FINDINGS: Besides its direct antitumor effects, lenvatinib recruited cytotoxic GZMK+CD8 T cells in intratumor stroma by CXCL9 from tumor-associated macrophages, suggesting that lenvatinib-treated HCC is in the so-called excluded condition that can diminish ICI efficacy.

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.

Transient loss of consciousness immediately after total pancreatectomy for pancreatic metastases from renal cell carcinoma: a case report.

BACKGROUND: Total pancreatectomy (TP) is often selected for treatment of various pancreatic diseases. However, the resultant lack of autoregulation of glycometabolism necessitates careful postoperative management. CASE PRESENTATION: A 77-year-old man who had undergone right nephrectomy for renal cell carcinoma 11 years previously presented with multiple histologically diagnosed pancreatic metastases. The patient had no notable comorbidities, including diabetes. Because no extrapancreatic organ metastasis was identified, he underwent TP as a curative treatment. He awoke from anesthesia and was extubated without any problems in the operating room. However, 15 min after entering the intensive care unit, he suddenly lost consciousness and became apneic, resulting in reintubation. Blood gas analysis revealed an increased glucose concentration (302 mg/dL) and mixed acid-base disorder (pH of 7.21) due to insulin insufficiency and fentanyl administration. After induction of continuous intravenous insulin infusion and termination of fentanyl, the glucose concentration and pH gradually improved. He regained clear consciousness and spontaneous ventilation and was extubated the next day with no difficulties or complications. CONCLUSION: This case highlights the importance of active monitoring of the glycemic state and pH after TP because of the possibility of deterioration due to TP itself as well as the lingering effects of anesthesia.

Liver Resection for Hepatocellular Carcinoma With Tumor Thrombus in the Inferior Vena Cava or Right Atrium: A Large-scale Multicenter Survey Conducted in Japan.

OBJECTIVE: To clarify the short and long-term postoperative outcomes and surgical indications for patients accompanied by hepatocellular carcinoma with tumor thrombus (TT) in the inferior vena cava (IVC) or right atrium (RA). BACKGROUND: These patients are known to have an extremely poor prognosis; however, the postoperative outcomes have not been fully verified because of the rarity of this disease. METHODS: We contacted 211 specialized centers in Japan and collected data on liver resection for hepatocellular carcinoma with TT in the IVC or RA from centers with experience performing surgery for such patients. The patient characteristics, operative procedures, and surgical outcomes were then analyzed. RESULTS: A total of 119 patients from 23 institutions were enrolled; 49 patients had TT in the IVC below the diaphragm (type I), 42 had TT in the IVC above the diaphragm (type II), and 28 had TT entering the RA (type III). The severity and frequency of postoperative complications did not differ among the 3 groups. There was one surgery-related death in the type III group. The median survival times were 2.47 years in the type I group, 1.77 years in the type II group, and 1.02 years in the type III group. Multivariate analysis identified an indocyanine green retention rate at 15 minutes >15% and ≥3 tumors as prognostic factors affecting survival, whereas the use of cardiopulmonary bypass and ≥3 tumors were risk factors for recurrence. CONCLUSIONS: As the postoperative prognosis of patients with type I or type II disease and of patients with no risk factors is relatively good, surgery should be considered for these patient populations.

Venous invasion and lymphatic invasion are correlated with the postoperative prognosis of pancreatic neuroendocrine neoplasm.

BACKGROUND: To determine treatment strategies corresponding to a wide range of pancreatic neuroendocrine neoplasms staging, easier-to-use and detailed prognostic classification is required. METHODS: Patients with pancreatic neuroendocrine neoplasms who underwent curative-intent surgery at the University of Tokyo Hospital between 2000 and 2018 were retrospectively reviewed. The presence or absence of venous and lymphatic invasion was assessed. Multivariable analysis was performed to identify the risk factors of shorter overall survival and recurrence-free survival. Patients were classified into the following 3 groups: a lymphovascular invasion 0 group, whereby both venous and lymphatic invasion were negative; an lymphovascular invasion 1 group, where either of the 2 was positive; and an lymphovascular invasion 2 group, where both were positive. The survival curves and recurrence patterns of the 3 groups were compared. RESULTS: Eighty-nine patients were analyzed. Multivariable analysis revealed that lymphatic invasion and Ki-67 index (≥ 3.0%) were independent prognostic factors of recurrence-free survival (hazard ratio: 5.2 and 3.6). Fifty-three patients were classified as lymphovascular invasion 0, 26 as lymphovascular invasion 1, and 10 as lymphovascular invasion 2. The recurrence-free survival curves of the 3 groups were significantly stratified (10-year recurrence-free survival: 89.1% in lymphovascular invasion 0, 57.1% in lymphovascular invasion 1, and 18.3% in lymphovascular invasion 2). Five-year cumulative liver and lymph node metastasis of lymphovascular invasion 0, lymphovascular invasion 1, and lymphovascular invasion 2 were well stratified at 0% and 3.8%, 15.8% and 23.1%, and 33.3% and 70.0%, respectively. CONCLUSION: Postoperative prognosis of resected pancreatic neuroendocrine neoplasms could be finely classified by venous invasion and lymphatic invasion. Management after curative-intent surgery for pancreatic neuroendocrine neoplasms may be changed by this new classification.

Automated liver tumor detection in abdominal ultrasonography with a modified faster region-based convolutional neural networks (Faster R-CNN) architecture.

Background: Although diagnostic ultrasound can non-invasively capture the image of abdominal viscera, diagnosis of the continuous ultrasound liver images to detect a liver tumor effectively and to determine whether the detected is benign or malignant is nontrivial. In order to minimize the gaps in diagnostic accuracy depending on doctor's proficiency, we built an automated system to support the ultrasonography of liver tumors by employing deep learning technologies. Methods: We constructed a neural network model for the automated detection of tumor tissues and blood vessels from the sequential liver ultrasound images. Faster region-based convolutional neural networks (Faster R-CNN) is employed as a base model for the object detection, which can output the detection results in 4 frames per second and enable the system to be particularly suitable for the real time ultrasonography. Moreover, we proposed a new neural network architecture feeding both the current and previous images into Faster R-CNN. For training the models, intraoperative ultrasound images obtained from one hepatocellular carcinoma (HCC) patient were used. The obtained image was a multifaceted observation of the liver and includes one HCC and some blood vessels. We labeled 91 images with the help of a liver specialist. We compared the tumor detection performance of the plain Faster R-CNN model with that of the proposed model. Results: We find that both the models performed well in detecting HCC and blood vessels, after training with 400 epochs using Adam. However, the mean precision of our model reaches 0.549, which is 0.019 better than that of the plain Faster R-CNN, and the mean sensitivity of our model about HCC reaches 0.623±0.385 for 30 scenes of sequential liver ultrasound images, which is also 0.146 better than that of the plain Faster R-CNN model. Conclusions: The comparison between the proposed model and the plain Faster R-CNN model shows that we achieved better accuracy in tumor detection, in terms of the mean precision as well as the mean sensitivity, with the proposed model.

Optimal tumor numbers in surgical candidates for multiple hepatocellular carcinomas.

BACKGROUND: According to the American Association for the Study of Liver Diseases guidelines, liver resection is not recommended for multiple hepatocellular carcinomas, although it is performed in Asian countries, including Japan. However, the maximum number, location, and recurrence types of tumors have not been reported in detail. METHODS: This retrospective study analyzed data for 1,170 patients who underwent surgical resection for hepatocellular carcinoma between October 2002 and December 2020 in a Japanese tertiary care hospital. Statistical analysis was performed to compare the surgical short-term and long-term outcomes among patients with >3 tumors and those with ≤3 tumors. RESULTS: This study of patients who underwent liver resection identified 775 who had a single tumor and compared overall survival rates with 477 who had multiple hepatocellular carcinomas: 242 had 2 hepatocellular carcinomas, 79 had 3 hepatocellular carcinomas, and 74 had >3 hepatocellular carcinomas. The median survival times based on the number of tumors were 9.74 years for a single tumor, 6.36 years for 2 tumors, 7.21 years for 3 tumors, 3.31 years for 4 tumors, and 3.48 years for 5 tumors. The median survival time was significantly worse in patients with >3 tumors than in those with 3 tumors (P < .0001). Concerning the type of treatments for recurrence, the patients who underwent surgical treatment had significantly better survival after recurrence than patients who underwent other treatments (8.32 vs 3.19 years; P < .001). CONCLUSION: The overall survival after liver resection was significantly worse for patients with >3 tumors than for those with <3 tumors. However, liver resection can be recommended for patients with 2 or 3 hepatocellular carcinomas because an acceptable median survival (>5 years) can be expected.

The impact of the covalently closed circular DNA level on recurrence of hepatocellular carcinoma after initial hepatectomy: an analysis of patients with resolved hepatitis B virus infection.

BACKGROUND: We assessed whether or not covalently closed circular DNA (cccDNA) levels in the background liver influence the recurrence of hepatocellular carcinoma (HCC) in patients with resolved hepatitis B virus (HBV) infection. METHODS: Among 425 patients who underwent initial hepatectomy for HCC between 2010 and 2018, a retrospective review was performed in 44 with resolved HBV infection. The clinicopathologic characteristics were analyzed for correlation with tumor recurrence. The HBV cccDNA levels were tested via a droplet digital polymerase chain reaction assay. RESULTS: HBV cccDNA was detected in 27 of 44 patients (61%), and the median level was 1.0 copies/1000 ng (range, 0-931.3 copies/1000 ng). Anti-HBc ≥8.9 S/CO was associated with cccDNA detection (odds ratio, 11.08; 95% confidence interval [95% CI], 2.48-49.46; P = 0.002). Twenty-eight patients (64%) developed HCC recurrence after hepatectomy. The overall 3- and 5-year recurrence-free survival rates were 45.7% and 34.3%, respectively.19 HBV cccDNA levels was not significantly associated with HCC recurrence, while the presence of multiple tumors was an independent risk fact or (hazard ratio, 6.53; 95% CI, 2.48-17.19; P < 0.001. CONCLUSION: HBV cccDNA levels did not influence HCC recurrence after hepatectomy. Anti-HBc levels may be used as a surrogate marker for cccDNA.

Preoperative Predictive Features of Invasive Carcinoma Among Intraductal Papillary Mucinous Neoplasm of the Pancreas.

OBJECTIVE: Noninvasive intraductal papillary mucinous neoplasms (IPMNs) theoretically do not metastasize. The purpose of this study is to preoperatively distinguish invasive carcinomas associated with IPMN from noninvasive IPMN. METHODS: A total of 131 patients who underwent surgical resection for IPMN were retrospectively analyzed to identify the predictors of invasive carcinoma, based on the International Association of Pancreatology Consensus Guidelines. RESULTS: Of the 131 patients, 29 (22%) had invasive carcinomas and 102 (78%) had noninvasive IPMN. An enhancing mural nodule (MN) greater than or equal to 5 mm, obstructive jaundice, an abrupt change in the caliber of the pancreatic duct (PD) with distal pancreatic atrophy, and lymphadenopathy were the significant predictors of invasive carcinoma in univariate analysis. The optimal cutoff value for the size of the enhancing MN to differentiate invasive carcinoma was 13 mm. In multivariate analysis, enhancing MN greater than or equal to 13 mm, obstructive jaundice, and an abrupt change in the PD caliber were the independent predictors. When all these factors were absent, only 17% were invasive carcinomas. CONCLUSIONS: Enhancing MN greater than or equal to 13 mm, obstructive jaundice, and an abrupt change in the PD caliber were predictive factors for invasive carcinoma. Systematic lymph node dissection may be omitted when a high-risk patient has none of these factors.