佐田 尚宏

This study explores a novel therapeutic approach for peritoneal metastasis (PM) using AAV-mediated delivery of tumor suppressor microRNA-29b (miR-29b) to peritoneal mesothelial cells (PMC). AAV serotypes 2 and DJ demonstrate high transduction efficiency for human and murine PMC, respectively. In vitro analysis indicates that AAV vectors encoding miR-29b precursor successfully elevate miR-29b expression in PMC and their secreted small extracellular vesicle (sEV), thereby inhibiting mesothelial mesenchymal transition and reducing subsequent attachment of tumor cells. A single intraperitoneal (IP) administration of AAV-DJ-miR-29b demonstrates robust and sustained transgene expression, suppressing peritoneal fibrosis and inhibiting the development of PM from gastric and pancreatic cancers. Additionally, AAV-DJ-miR-29b enhances the efficacy of IP chemotherapy using paclitaxel, restraining the growth of established PM. While conventional gene therapy for cancer encounters challenges targeting tumor cells directly but delivering miRNA to the tumor stroma offers a straightforward and efficient means of altering the microenvironment, leading to substantial inhibition of tumor growth. AAV-mediated miR-29b delivery to peritoneum via IP route presents a simple, minimally invasive, and promising therapeutic strategy for refractory PM.

Despite advances in systemic chemotherapy, patients with gastric cancer (GC) and peritoneal metastases (PMs) continue to have poor prognoses. Intraperitoneal (IP) administration of Paclitaxel (PTX) combined with systemic chemotherapy shows promise in treating PMs from GC. However, methods of drug administration need to be optimized to maximize efficacy. In this study, we utilized a mouse model with PMs derived from a human GC cell line, administering PTX either IP or intravenously (IV), and Carboplatin (CBDCA) IV 0, 1, and 4 days after PTX administration. The PMs were resected 30 min later, and concentrations of PTX and CBDCA in resected tumors were measured using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Results indicated that PTX concentrations were higher with IP administration than with IV administration, with significant differences observed on days 0 and 1. CBDCA concentrations 4 days post-IP PTX administration were higher than with simultaneous IV PTX administration. These findings suggest that IP PTX administration enhances CBDCA concentration in peritoneal tumors. Therefore, sequential IV administration of anti-cancer drugs appears more effective than simultaneous administration with IP PTX, a strategy that may improve prognoses for patients with PMs.

PURPOSE: Low anterior resection syndrome (LARS) causes devastating symptoms and impairs the quality of life (QOL). This study investigated the incidence and risk factors of LARS and their association with the QOL in patients with lower rectal tumors. METHODS: Patients who underwent anus-preserving surgery for lower rectal tumors between 2014 and 2019 and who had anal defecation between 2020 and 2021 were surveyed. The LARS score measured severity, and the QOL was evaluated using the Japanese version of the Fecal Incontinence Quality-of-Life Scale (JFIQL). The primary endpoint was the incidence of Major LARS, and the secondary endpoints were risk factors and association with the JFIQL. RESULTS: Of 107 eligible patients, 82 (76.6%) completed the LARS survey. The incidence of Major LARS was 48%. Independent risk factors included neoadjuvant chemoradiotherapy (CRT) and a short interval (< 24 months after surgery; odds ratio, 4.6; 95% confidence interval: 1.1-19, both). The LARS score was moderately correlated with the JFIQL generic score (correlation coefficient: - 0.54). The JFIQL scores were significantly worse in the Minor and Major LARS groups than in the No LARS group. CONCLUSIONS: Major LARS was found in 48% of lower rectal tumors, and independent risk factors include neoadjuvant CRT and a short interval. The QOL was significantly impaired in patients with both Minor and Major LARS.

Abstract Background Osteopenia reflects frailty and has been shown to be associated with outcomes in cancer patients. This study was undertaken to examine whether osteopenia is an independent prognostic factor in patients with esophageal cancer after resection. Methods A total of 214 patients who underwent surgery for esophageal cancer were analyzed retrospectively. Bone mineral density (BMD) of the 11th thoracic vertebra was measured by computed tomography scan, and patients classified into osteopenia and normal BMD groups with BMD &lt;160 Hounsfield units as the cutoff. Clinicopathological data and prognosis were analyzed. Results The 5‐year survival rate was 55.4% for the osteopenia group and 74.7% for the normal BMD group with a significantly worse prognosis in the osteopenia group (p = 0.0080). In multivariable analysis, osteopenia was a significant independent risk factor associated with overall survival (hazard ratio [HR] 1.90, 95% confidence interval [CI] 1.27–3.34, and p = 0.0151) along with R1/2 resection (HR 3.02, 95% CI 1.71–5.18, and p = 0.0002). Conclusion In patients with esophageal cancer undergoing resection, osteopenia may be a surrogate marker for frailty and an independent predictor of prognosis.

Background: Osteopenia is a well-known risk factor for survival in patients with hepatocellular carcinoma; however, it is unclear whether osteopenia can apply to both genders and how osteopenia is associated with cancer progression. The aim of this study was to elucidate whether osteopenia predicts reduced survival in regression models in both genders and whether osteopenia is associated with the pathological factors associated with reduced survival. Methods: This study included 188 consecutive patients who underwent hepatectomy. Bone mineral density was assessed using computed tomography (CT) scan images taken within 3 months before surgery. Non-contrast CT scan images at the level of the 11th thoracic vertebra were used. The cutoff value of osteopenia was calculated using a threshold value of 160 Hounsfield units. Overall survival (OS) curves and recurrence-free survival (RFS) were constructed using the Kaplan–Meier method, as was a log-rank test for survival. The hazard ratio and 95% confidence interval for overall survival were calculated using Cox’s proportional hazard model. Results: In the regression analysis, age predicted bone mineral density. The association in females was greater than that in males. The OS and RFS of osteopenia patients were shorter than those for non-osteopenia patients. According to univariate and multivariate analyses, osteopenia was an independent risk factor for OS and RFS. The sole pathological factor associated with osteopenia was microvascular portal vein invasion. Conclusion: Models suggest that osteopenia may predict decreased OS and RFS in patients undergoing resection of hepatocellular carcinoma due to the mechanisms mediated via microvascular portal vein invasion.

Abstract The vagus nerve is the only pathway for transmitting parasympathetic signals between the brain and thoracoabdominal organs, thereby exhibiting anti-inflammatory functions through the cholinergic anti-inflammatory pathway. Despite often being resected during lymph node dissection in upper gastrointestinal cancer surgery, the impact of vagotomy on postoperative outcomes in gastric cancer patients remains unclear. Sub-diaphragmatic vagotomy was performed on C57BL/6 mice. Three weeks later, syngeneic murine gastric cancer cell line YTN16P was injected into the peritoneal cavity, and the number of peritoneal metastases (PM) on the mesentery and omentum compared with control mice. The phenotypes of immune cells in peritoneal lavage and omental milky spots one day after tumor inoculation were analyzed using flow cytometry and immunohistochemistry. Intraperitoneal transfer of 3 × 10⁵ YTN16P significantly increased the number of metastatic nodules on the mesentery in the vagotomy group compared to the control group. The omental metastasis grade was also significantly higher in the vagotomy group. Phenotypic analysis of immune cells in peritoneal lavage did not reveal significant differences after vagotomy. However, vagotomized mice exhibited a notable increase in milky spot area, with a higher presence of cytokeratin(+) tumor cells, F4/80(+) macrophages, and CD3(+) T cells. Vagus nerve signaling appears to regulate the immune response dynamics within milky spots against disseminated tumor cells and inhibits the development of PM. Preserving the vagus nerve may offer advantages in advanced gastric cancer surgery to reduce peritoneal recurrence.

The liver and pancreas work together to recover homeostasis after hepatectomy. This study aimed to investigate the effect of liver resection volume on the pancreas. We collected clinical data from 336 living liver donors. They were categorized into left lateral sectionectomy (LLS), left lobectomy, and right lobectomy (RL) groups. Serum pancreatic enzymes were compared among the groups. Serum amylase values peaked on postoperative day (POD) 1. Though they quickly returned to preoperative levels on POD 3, 46% of cases showed abnormal values on POD 7 in the RL group. Serum lipase levels were highest at POD 7. Lipase values increased 5.7-fold on POD 7 in the RL group and 82% of cases showed abnormal values. The RL group's lipase was twice that of the LLS group. A negative correlation existed between the remnant liver volume and amylase (r = - 0.326)/lipase (r = - 0.367) on POD 7. Furthermore, a significant correlation was observed between POD 7 serum bilirubin and amylase (r = 0.379)/lipase (r = 0.381) levels, indicating cooccurrence with liver and pancreatic strain. Pancreatic strain due to hepatectomy occurs in a resection/remnant liver volume-dependent manner. It would be beneficial to closely monitor pancreatic function in patients undergoing a major hepatectomy.

Recent evidence indicates ferroptosis is implicated in the pathophysiology of various liver diseases; however, the organ-specific regulation mechanism is poorly understood. Here, we demonstrate 7-dehydrocholesterol reductase (DHCR7), the terminal enzyme of cholesterol biosynthesis, as a regulator of ferroptosis in hepatocytes. Genetic and pharmacological inhibition (with AY9944) of DHCR7 suppress ferroptosis in human hepatocellular carcinoma Huh-7 cells. DHCR7 inhibition increases its substrate, 7-dehydrocholesterol (7-DHC). Furthermore, exogenous 7-DHC supplementation using hydroxypropyl β-cyclodextrin suppresses ferroptosis. A 7-DHC-derived oxysterol metabolite, 3β,5α-dihydroxycholest-7-en-6-one (DHCEO), is increased by the ferroptosis-inducer RSL-3 in DHCR7-deficient cells, suggesting that the ferroptosis-suppressive effect of DHCR7 inhibition is associated with the oxidation of 7-DHC. Electron spin resonance analysis reveals that 7-DHC functions as a radical trapping agent, thus protecting cells from ferroptosis. We further show that AY9944 inhibits hepatic ischemia-reperfusion injury, and genetic ablation of Dhcr7 prevents acetaminophen-induced acute liver failure in mice. These findings provide new insights into the regulatory mechanism of liver ferroptosis and suggest a potential therapeutic option for ferroptosis-related liver diseases.

Abstract Intestinal adaptation does not necessarily recover absorptive capacity in short bowel syndrome (SBS), sometimes resulting in intestinal failure-associated liver disease (IFALD). Additionally, its therapeutic options remain limited. Polyamines (spermidine and spermine) are known as one of the autophagy inducers and play important roles in promoting the weaning process; however, their impact on intestinal adaptation is unknown. The aim of this study was to investigate the impact of polyamines ingestion on adaptation and hepatic lipid metabolism in SBS. We performed resection of two-thirds of the small intestine in male Lewis rats as an SBS model. They were allocated into three groups and fed different polyamine content diets (0%, 0.01%, 0.1%) for 30 days. Polyamines were confirmed to distribute to remnant intestine, whole blood, and liver. Villous height and number of Ki-67-positive cells in the crypt area increased with the high polyamine diet. Polyamines increased secretory IgA and mucin content in feces, and enhanced tissue Claudin-3 expression. In contrast, polyamines augmented albumin synthesis, mitochondrial DNA copy number, and ATP storage in the liver. Moreover, polyamines promoted autophagy flux and activated AMP-activated protein kinase with suppression of lipogenic gene expression. Polyamines ingestion may provide a new therapeutic option for SBS with IFALD.

Abstract The spleen is a key source of circulating and tumor-infiltrating immune cells. However, the effect of splenectomy on tumor growth remains unclear. At 3 weeks after splenectomy, we subcutaneously injected LuM1 cells into BALB/c mice and evaluated the growth of primary tumors and lung metastases at 4 weeks after tumor inoculation. In addition, we examined the phenotypes of immune cells in peripheral blood by using flow cytometry and in tumor tissue by using multiplex immunohistochemistry. The growth of primary tumors was reduced in splenectomized mice compared with the sham-operated group. Conversely, splenectomized mice had more lung metastases. Splenectomized mice had fewer CD11b⁺cells, especially monocytic MDSCs (CD11b⁺Gr-1^neg-lowLy6c^high), and NK cells (CD49b⁺CD335⁺). The proportion of NK cells was inversely correlated with the number of lung metastases. In splenectomized mice, the density of CD3⁺ and granzyme B⁺ CD8⁺ T cells was increased, with fewer M2-type macrophages in primary tumors, but NK cells were decreased markedly in lung. Splenectomy concurrently enhances T cell-mediated acquired immunity by reducing the number of monocytic MDSCs and suppresses innate immunity by decreasing the number of NK cells. Splenectomy has opposite effects on primary and metastatic lesions through differential regulation on these two immune systems.

BACKGROUND: Adjuvant nivolumab therapy has become the standard therapy for patients with localized advanced esophageal cancer with non-pathological complete response after neoadjuvant chemoradiotherapy followed by curative surgery. However, the necessity of this therapy for patients after neoadjuvant chemotherapy (NAC) with docetaxel, cisplatin, and 5-fluorouracil (DCF) regimen followed by surgery is unclear, and the prognosis of grouping based on the presence or absence of pathological tumor and lymph node findings has not been analyzed. Therefore, our study aimed to address these questions. METHODS: This retrospective cohort study included patients with cT1N1-3M0 and cT2-3N0-3M0 esophageal cancer according to the Japanese Classification of Esophageal Cancer, 11th edition, who received NAC with DCF followed by curative surgery between 2008 and 2020 at Jichi Medical University Hospital. We divided patients with ypT0-3N0-3M0 into four histological groups, namely ypT0N0, ypT+N0, ypT0N+, and ypT+N+, and we evaluated overall survival as the primary outcome and the prognostic relationship of lymph node metastasis as the secondary outcome. RESULTS: A total of 101 patients were included in this study. Kaplan-Meier analysis showed that the curves of the ypT0N0 and ypT+N0 groups were almost identical, while they differed from the other two groups. The hazard ratio of ypN+ was 4.44 (95% confidence interval: 2.03-9.71; P<0.001). CONCLUSIONS: The prognosis of the ypT+N0 group after NAC with DCF followed by surgery was similar to that of pathological complete remission. Grouping patients according to pathological lymph node status is a reasonable predictor of prognosis.

INTRODUCTION: Treatment guidelines for colorectal cancer (CRC) suggest two classifications for histological differentiation-highest-grade and predominant. However, the optimal predictor of lymph node metastasis (LNM) in T1 CRC remains unknown. This systematic review aimed to evaluate the impact of the use of highest-grade or predominant differentiation on LNM determination in T1 CRC. METHODS: The study protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO, registration number: CRD42023416971) and was published in OSF (https://osf.io/TMAUN/) on April 13, 2023.We searched five electronic databases for studies assessing the diagnostic accuracy of highest-grade or predominant differentiation to determine LNM in T1 CRC. The outcomes were sensitivity and specificity. We simulated 100 T1 CRC cases, with an LNM incidence of 11.2%, to calculate the differences in false positives and negatives between the highest-grade and predominant differentiations using a bootstrap method. RESULTS: In 42 studies involving 41,290 patients, the differentiation classification had a pooled sensitivity of 0.18 (95% confidence interval [CI], 0.13-0.24) and 0.06 (95% CI, 0.04-0.09) (P<0.0001) and specificity of 0.95 (95% CI, 0.93-0.96) and 0.98 (95% CI, 0.97-0.99) (P<0.0001) for the highest-grade and predominant differentiations, respectively. In the simulation, the differences in false positives and negatives between the highest-grade and predominant differentiations were 3.0% (range, 1.6-4.4) and -1.3% (range, -2.0 to -0.7), respectively. CONCLUSIONS: Highest-grade differentiation may reduce the risk of misclassifying LNM cases as negative, whereas predominant differentiation may prevent unnecessary surgeries. Further studies should examine differentiation classification using other predictive factors.

Lateral lymph node (LLN) metastasis in T1 rectal cancer has an incidence of less than 1%. However, its clinical features are largely uncharted. We report a case of LLN metastasis in T1 rectal cancer and review the relevant literature. A 56-year-old female underwent rectal resection for lower rectal cancer 2 years previously (pT1bN0M0). During follow-up, an elevated tumor marker CA19-9 was documented. Enhanced CT and MRI showed a round shape nodule 2 cm in size on the left side of pelvic wall. PET-CT showed high accumulation of FDG in the same lesion, leading to a diagnosis of isolated LLN recurrence. Because no other site of recurrence was detected, surgical resection of the LLN was performed. Microscopic findings were consistent with metastatic lymph node originating from the recent rectal cancer. Adjuvant chemotherapy for six months was given, and patient remains free of recurrent disease seven months after LLN resection. Although LLN recurrence after surgery for T1 rectal cancer is rare, post-surgical follow-up should not be omitted. When LLN metastasis is suspected on CT, MRI and/or PET-CT will be recommended. Surgical resection of LLN metastasis in patients with T1 rectal cancer may lead to favorable outcomes, when recurrence in other areas is not observed.

AIM: Low anterior resection syndrome (LARS) causes devastating symptoms and impairs quality of life (QOL). Although its incidence and risk factors have been reported, these data are scarce in Japan. This study aimed to elucidate the incidence and risk factors of LARS as well as to evaluate its association with QOL in Japanese patients. METHOD: Patients with anal defecation at the time of the survey between November 2020 and April 2021 were included, among those who underwent anus-preserving surgery for rectal tumors between 2014 and 2019 in tertiary referral university hospital. The severity of LARS and QOL were evaluated with the LARS score and the Japanese version of the fecal incontinence quality of life scale (JFIQL), respectively. Primary endpoint was the incidence of major LARS. Secondary endpoints were risk factors and association with JFIQL. RESULTS: Of 332 eligible patients, 238 (71.7%) answered the LARS survey completely. The incidence of major LARS was 22% overall, and 48% when limited to lower tumors. Independent risk factors included lower tumors (OR: 7.0, 95% CI: 2.1-23.1, p = 0.001) and surgical procedures with lower anastomoses (OR: 4.6, 95% CI: 1.2-18.5, p = 0.03). The JFIQL generic score correlated moderately with the LARS score (correlation coefficient of -0.65). The JFIQL generic score was also significantly lower in lower tumors. CONCLUSIONS: The incidence of major LARS is 22% in Japanese patients, and independent risk factors include lower tumors and surgical procedures with lower anastomoses. More severe LARS is associated with worse QOL which is significantly more impaired in patients with lower tumors.

OBJECTIVES: The aim of this study was to identify the microbiota whose decrease in tumor area was associated with the metastatic process of distal colorectal cancer (CRC). METHODS: Twenty-eight consecutive patients with distal CRC undergoing surgical resection in our hospital were enrolled. Microbiota in 28 specimens from surgically resected colorectal cancers were analyzed using 16S ribosomal ribonucleic acid gene amplicon sequencing and the relative abundance (RA) of microbiota was evaluated. The densities of tumor-infiltrating lymphocytes (TIL) and tumor associated macrophages (TAM) in the colorectal cancers were immunohistochemically evaluated. RESULTS: Phocaeicola was the most abundant microbiota in normal mucosa. The RA of Phocaeicola in tumor tissues tended to be lower than that in normal mucosa although the difference was not significant (p=0.0732). The RA of Phocaeicola at tumor sites did not correlate either with depth of tumor invasion (pT-stage) or tumor size, however they were significantly reduced in patients with nodal metastases (p<0.05) and those with distant metastases (p<0.001). The RA of Phocaeicola at tumor sites showed positive correlation with the densities of CD3(+) or CD8(+) TIL. Since P. vulgatus was the most dominant species (47%) of the Phocaeicola, the RA of P. vulgatus and CRC metastasis and its association with TIL and TAM were also investigated. P. vulgatus showed a similar trend to genus Phocaeicola but was not statistically significant. CONCLUSIONS: A relative reduction of Phocaeicola attenuates the local anti-tumor immune response in distal CRC, which may facilitate metastatic spread.

Segmental grafts from living donors have advantages over grafts from deceased donors when used for small intestine transplantation. However, storage time for small intestine grafts can be extremely short and optimal graft preservation conditions for short-term storage remain undetermined. Secreted factors from mesenchymal stem cells (MSCs) that allow direct activation of preserved small intestine grafts. Freshly excised Luc-Tg LEW rat tissues were incubated in preservation solutions containing MSC-conditioned medium (MSC-CM). Preserved Luc-Tg rat-derived grafts were then transplanted to wild-type recipients, after which survival, injury score, and tight junction protein expression were examined. Luminance for each graft was determined using in vivo imaging. The findings indicated that 30-100 and 3-10 kDa fractions of MSC-CM have superior activating effects for small intestine preservation. Expression of the tight-junction proteins claudin-3, and zonula occludens-1 preserved for 24 h in University of Wisconsin (UW) solution containing MSC-CM with 50-100 kDa, as shown by immunostaining, also indicated effectiveness. Reflecting the improved graft preservation, MSC-CM preloading of grafts increased survival rate from 0% to 87%. This is the first report of successful transplantation of small intestine grafts preserved for more than 24 h using a rodent model to evaluate graft preservation conditions that mimic clinical conditions.

The prognosis of patients with peritoneal metastases from pancreatic cancer is poor, largely due to massive ascites, which precludes systemic treatment. Two patients with a poor performance status and malignant ascites were treated with cell-free and concentrated ascites reinfusion therapy followed by combined chemotherapy with intraperitoneal paclitaxel, intravenous gemcitabine, and nab-paclitaxel. These patients achieved a survival of 19 and 36 weeks with a relatively good quality of life. Combined intraperitoneal paclitaxel and systemic chemotherapy may provide effective palliative management for some patients with peritoneal metastases from pancreatic cancer.

Although miR-29b levels in peritoneal exosomes was markedly reduced in patients with peritoneal metastases(PM), their role has not been fully clarified. Bone marrow derived mesenchymal stem cells(BMSC)were transfected with miR-29b- integrating lentivirus and exosomes isolated from culture supernatants using ultracentrifugation. The effects of the exosomes on human peritoneal mesothelial cells(HPMC)were examined in vitro. The in vivo effect of murine BMSC-derived exosomes was examined with a syngeneic PM model. Culture of HPMC with TGF-β1 decreased expression of E-cadherin and calretinin with increased expression of vimentin, totally restored by adding miR-29b-rich exosomes. The exosomes inhibited proliferation and migration of HPMC, and inhibited adhesion of gastric cancer cells to HPMC. Intraperitoneal(IP)transfer of miR- 29b-rich exosomes every 3 days markedly reduced the number of PM of a murine gastric cancer cell, YTN16P, on the mesentery of C57/BL6 mice. IP administration of miR-29b-containing exosome suppresses the development of PM of gastric cancer.

腸管重積型逆流防止弁付加手術を行った胆道閉鎖症(BA)において,挙上空腸狭窄が難治性胆管炎の契機となり,生体肝移植(LDLT)を施行した2例を報告する.【症例1】15歳女児.生後1ヵ月時にBAに対して肝門部空腸吻合術を施行したが,胆汁排泄不良で生後2ヵ月時に逆流防止弁付き再吻合術を施行した.術後15年時に挙上空腸狭窄による難治性胆管炎に対してイレウス管を留置したが,肝内胆管数珠状拡張と黄疸は改善せず,LDLTを施行した.【症例2】26歳男性.生後4ヵ月時にBAに対して逆流防止弁付き肝門部空腸吻合術を施行した.術後25年時に黄疸を伴う胆管炎が出現したため,挙上空腸狭窄に対してENBDチューブを留置したが,胆管炎は改善せず,LDLTを施行した.逆流防止弁は長期BAにおいて挙上空腸狭窄による難治性胆管炎の原因になることがある.(著者抄録)

Abstract It is important to assess the prognosis and intervene before and after surgery in patients with hepatocellular carcinoma. This study aims to elucidate the association of outcomes and residual liver function after hepatectomy. A total of 176 patients who underwent the initial resection for hepatocellular carcinoma between January 2011 and March 2021 at Jichi Medical University were included. Hepatic clearance of the remnant liver was measured using 99mTc-galactosyl serum albumin scintigraphy. The log-rank test was used to analyze survival using the Kaplan–Meier method. Hazard ratios (HR) and 95% confidence intervals (CI) for overall survival were calculated using Cox’s proportional hazard model. In multivariate analysis, microvascular invasion, intraoperative blood loss, and hepatic clearance of the remnant liver were independently associated with overall survival. Hepatic clearance of the remnant liver was independently associated with recurrence free survival. This is the first report to show that lower residual liver function is associated with shorter survival in patients with hepatocellular carcinoma undergoing hepatectomy. Preoperative determination of remnant liver function may allow assessment of prognosis in patients planned to undergo resection of hepatocellular carcinoma. Preservation of liver functional reserve may be crucial for improved long-term outcomes after hepatectomy.

Introduction Postoperative pancreatic fistula (POPF) is a critical complication occurring with a high incidence after distal pancreatectomy. To minimize the risk of POPF, we developed an innovative pancreas ligation device capable of closing the pancreatic stump without causing traumatic injury to the pancreatic duct and artery. We conducted an ex vivo follow-up study to compare the pressure resistance of the pancreas ligation device with that of a regular linear stapler. Materials and methods The pancreases were excised from 20 pigs and divided into two groups: ligation group (n = 10) and stapler group (n = 10). Distal pancreatectomy was performed, and the pancreatic stump was closed using either a pancreas ligation device or a regular linear stapler. The main pancreatic duct was cannulated with a 4-French catheter connected to a cannula and syringe filled with contrast medium. Using fluoroscopy detection, pressure resistance was defined as the maximum pressure without leakage from the pancreatic stump. Results No significant differences were found between the two groups regarding sex, age, body weight, or pancreatic thickness. In the ligation group, no leakage was observed at the stump in any pancreas. However, in the stapler group, six of 10 pancreases showed leakage at the staple line or into the parenchyma. Pressure resistance was significantly higher in the ligation group than in the stapler group (median: 42.8 vs. 34.3 mmHg, P = 0.023). Conclusions These findings suggest the effectiveness of a pancreas ligation device in reducing the incidence of POPF after distal pancreatectomy. Our ligation device is expected to be a useful alternative to a linear stapler for pancreatic stump closure.