Tomohiro Arita

Aim: This nationwide observational study investigated recent trends in pancreatic cancer (PC) incidence and surgical management in Japan. Methods: Annual data on PC incidence (2016–2021) and surgical procedures (2016–2023) were obtained from the Cancer Information Database and the National Database of Health Insurance Claims and Specific Health Checkups (NDB), respectively. Surgical procedures were categorized by type (distal pancreatectomy (DP, 2016–2023)/pancreatoduodenectomy (PD, 2020–2023)) and approach (open/laparoscopic). Crude and age‐adjusted rates per 100 000 person‐years were calculated. Temporal trends were evaluated using linear and Poisson regression to estimate annual risk ratios (RRs). Results: Over the study period, the annual average PC incidence was 43 015, and the average number of PC surgery was 13 899. Age‐adjusted PC incidence rates rose significantly among males, females, and both sexes (RR = 1.007, 1.016 and 1.011, respectively; p < 0.0001). A particularly notable rise was observed among females aged 10–29 years (RR range: 1.347–1.449; all p < 0.0009). DP rates increased significantly among males, females, and both sexes (RR = 1.033, 1.032, and 1.033, respectively; p < 0.0001), with marked increases among individuals aged 65–89 years for both sexes (RR range: 1.018–1.114; all p < 0.0012). PD volumes also rose during 2020–2023, although the limited analytic window precluded formal rate‐based trend evaluation. In 2023, PD comprised 65.6% of PC surgeries (9444/14397), while DP comprised 34.4% (4953/14397). Conclusion: These nationwide findings highlight age‐ and sex‐specific signals—notably an apparent rise among young women and increased DP use among older adults—that warrant further validation.

INTRODUCTION: The ligament of Treitz plays a critical role in maintaining the normal anatomical position of the duodenojejunal junction by suspending and fixing the proximal jejunum to the retroperitoneum.CASE PRESENTATION: A 77-year-old man receiving home-visit medical care after cerebral infarction and cerebral hemorrhage, who had undergone tracheostomy and gastrostomy, was admitted for aspiration pneumonia with respiratory failure. An abdominal CT demonstrated dilatation from the stomach to the proximal duodenum. The third portion of the duodenum coursed caudally without passing between the abdominal aorta and the superior mesenteric artery (SMA). The superior mesenteric vein was located to the right of the SMA at the L2 vertebral level, but to the left of the SMA at the L4 vertebral level, suggesting mesenteric rotation. After conservative decompression therapy, repeat imaging showed spontaneous restoration of normal anatomy. Given the patient’s history of recurrent aspiration pneumonia secondary to duodenal obstruction, elective laparoscopic surgery was performed. Intraoperatively, no intestinal malrotation or internal hernia was identified. The duodenojejunal junction showed incomplete retroperitoneal fixation, and the suspensory tissue corresponding to the ligament of Treitz was lax. Laparoscopic fixation of the proximal jejunum to the left retroperitoneum and gastrojejunostomy were performed. The patient was discharged on POD 41. No recurrent obstruction or aspiration events were observed during 9 months of follow-up.CONCLUSIONS: We report a rare case of recurrent duodenal obstruction with transient small bowel volvulus associated with incomplete fixation and abnormal mobility of the ligament of Treitz. When intermittent rightward displacement of the duodenojejunal junction is observed, this condition should be considered in the differential diagnosis in addition to intestinal malrotation.

INTRODUCTION: Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the sacroiliac joints and spine, which can lead to bony ankylosis during the healing process. The prevalence of AS in the Japanese population is relatively low, and encounters with such patients in routine clinical practice are uncommon.CASE PRESENTATION: The patient was a 53-year-old man with a history of AS under ongoing treatment. He had experienced epigastric discomfort and nausea for 1 month prior to presentation. Further examination suggested that his symptoms were caused by gallbladder stones, and laparoscopic cholecystectomy was performed. Intraoperative findings revealed restricted rib mobility and a low-lying costal arch due to AS, resulting in a very narrow working space in the upper abdomen. Since the dissection of Calot’s triangle was difficult, the fundus-first technique was employed to separate the gallbladder from the liver bed, followed by clipping and division of the cystic duct and cystic artery. No hemodynamic changes were observed in association with increased intra-abdominal pressure during surgery. The postoperative course was uneventful, and the patient was discharged on POD 3.CONCLUSIONS: We report a case of laparoscopic cholecystectomy performed in a patient with AS, supplemented by a review of the literature.

Peritoneal dissemination poses a critical challenge in advanced gastric cancer and leads to poor outcomes. Exosomes offer a novel platform for the delivery

Aim: The epidemiology of hemorrhoids is challenging because of variability in sampling methodologies and diagnostic criteria across different studies. This study indirectly clarified the epidemiology of hemorrhoids by investigating the number of invasive treatments for hemorrhoids (ITH) using a nationwide healthcare claims database.Methods: The annual number and rate of ITH procedures per 100 000 people during 2018–2022 were examined. ITH covered by the Japanese healthcare insurance includes sclerotherapy, rubber band ligation, infrared coagulation, thrombectomy, hemorrhoidectomy, and stapled hemorrhoidopexy. The demographic peak patterns in the sex‐ and age‐stratified data were analyzed. Annual trends were evaluated using the Jonckheere–Terpstra trend test or Poisson regression model.Results: Over the 5‐year period, the total number of ITH was 697 838, with a rate of 110.5 per 100 000 person‐years. The male‐to‐female ratio was 1.2:1, indicating slight male predominance. Demographic peak analysis revealed bimodal peaks in males aged 40–44 and 75–79 years, and in females aged 35–39 and 75–79 years. No significant changes were observed in all ITH procedures. The age‐adjusted number across all age groups per 100 000 person‐years demonstrated annual decreasing trends for males but increasing trends for females (p < 0.0167). Subgroup analysis indicated a decrease among older cohorts in both males and females, in contrast to an increase among young and middle‐aged females (p < 0.00088).Conclusion: Distinct bimodal ITH peaks were observed in males and females in their 30s–40s and 70s. These findings provide valuable insights into the epidemiology of hemorrhoids.

Background: Laparoscopic liver resection has a steep learning curve, and multiple difficulty‐scoring systems have been proposed to support safe implementation. Though the IWATE scoring system is widely used, the rationale for its tumor location score is unclear. The objective of our study was to establish a more accurate definition of tumor location based on subsegments of the Glisson branches.Methods: We included 176 patients who underwent laparoscopic liver resection between January 2017 and February 2024, excluding those who underwent multiple or concomitant resections of other organs. Tumor location was defined by the most proximal subsegment of the Glisson branches (1sp, Spiegel; 1pc, para‐caval; 1cp, caudate process; 3a, apical; 3b, basal; 4a; 4b; 5v, ventral; 5d, dorsal; 6v; 6d; 6 L, lateral; 7v; 7d; 8v; 8d).Results: Within each segment, comparing operative time between subsegments showed significant differences, except for S1 (3a vs. 3b, p = 0.011; 4a vs. 4b, p = 0.001; 5v vs. 5d, p = 0.012; 6v vs. 6d vs. 6 L, p = 0.007; 7v vs. 7d, p = 0.003; 8v vs. 8d, p = 0.030). Blood loss significantly differed except for S1 (3a vs. 3b, p = 0.018; 4a vs. 4b, p = 0.002; 5v vs. 5d, p = 0.016; 6v vs. 6d vs. 6 L, p = 0.011; 7v vs. 7d, p = 0.013; 8v vs. 8d, p < 0.001). The incidence of postoperative complications did not differ significantly; however, hospital stay was significantly different only in S4 (4a vs. 4b, p = 0.049).Conclusions: There are significant differences in the difficulty of laparoscopic liver resection among subsegments. More detailed scoring based on subsegments may improve accuracy, and we propose a new scoring system.

Aim: This observational study aimed to elucidate the regional disparities in rectal cancer (RC) and rectal resections (RRs) across Japan.Methods: The annual incidence of RC, and number of all RRs and board‐certified surgeons by the Japan Society for Endoscopic Surgery were examined by prefecture in Japan from 2014 to 2019. The surgical approaches were broken down by open and laparoscopic. Disparities in 47 prefectures and urban–rural disparities were evaluated using the Gini coefficient and unpaired t‐test.Results: The annual national average incidence of RC was 50 127 and the number of all RRs was 39 903. Gini coefficients for RC, and laparoscopic and all RRs were p < 0.05).Conclusion: RC and laparoscopic and all RRs exhibited minimal inter‐prefectural disparities. The urban–rural analysis revealed significant differences in the incidence/number of RC and board‐certified surgeons between urban and rural prefectures, despite minor differences in RRs regardless of approach. This pattern suggests a potential migration of surgical services from rural to urban areas. This preliminary study is expected to contribute to a basic epidemiological database for RC and RRs.

Objectives Pancreatic cancer (PC) is one of the most aggressive malignancies due to the high rate of metastasis. The mechanisms underlying metastasis need to be elucidated. Small extracellular vesicles (sEVs) mediate cell-to-cell communication, and cancer-derived sEVs contribute to the formation of pre-metastatic niches. The present study examined changes in adhesiveness by the internalization of PC-derived sEVs into vascular endothelial cells, and investigated the molecular mechanisms underlying metastasis. Methods PC-derived sEVs were internalized into vascular endothelial cells, and changes in adhesiveness were evaluated. We evaluated the effects of sEVs on the formation of liver metastasis in vivo. We also assessed molecular changes in vascular endothelial cells by the internalization of PC-derived sEVs. Results The internalization of PC-derived sEVs into vascular endothelial cells promoted the adhesiveness of vascular endothelial cells and PC cells. PC-derived sEVs contained high levels of transforming growth factor 1 mRNA and acted as its transporter. Once PC-derived sEVs were internalized into vascular endothelial cells, the expression of fibronectin 1 increased on the cell surface, and the adhesiveness of vascular endothelial cells was enhanced. Conclusions We investigated association between PC-derived sEVs and adhesiveness. Regulation of PC-derived sEVs has potential as a therapeutic modality to suppress the metastasis of PC.

Background Recent studies have identified that low levels of some tumour suppressor microRNAs (miRNAs) in the blood contribute to tumour progression and poor outcomes in various cancers. However, no study has proved these miRNAs are associated with cancer immune mechanisms. Methods From a systematic review of the NCBI and miRNA databases, four tumour suppressor miRNA candidates were selected (miR-5193, miR-4443, miR-520h, miR-496) that putatively target programmed cell death ligand 1 (PD-L1). Results Test-scale and large-scale analyses revealed that plasma levels of miR-5193 were significantly lower in gastric cancer (GC) patients than in healthy volunteers (HVs). Low plasma levels of miR-5193 were associated with advanced pathological stages and were an independent prognostic factor. Overexpression of miR-5193 in GC cells suppressed PD-L1 on the surface of GC cells, even with IFN-γ stimulation. In the coculture model of GC cells and T cells stimulated by anti-CD3/anti-CD28 beads, overexpression of miR-5193 increased anti-tumour activity of T cells by suppressing PD-L1 expression. Subcutaneous injection of miR-5193 also significantly enhanced the tumour-killing activity and trafficking of T cells in mice. Conclusions Low blood levels of miR-5193 are associated with GC progression and poor outcomes and could be a target of nucleic acid immunotherapy in GC patients.