Published papers

A 48-year-old woman presented with recurrent epigastric pain without significant medical or family history. Upper endoscopy revealed edematous mucosal changes in the descending duodenum, although the major papilla appeared normal. Duodenal biopsies showed only mild inflammatory infiltrates without an increase in IgG4-positive plasma cells. Contrast-enhanced CT showed enlargement of the pancreatic head with cystic changes and increased peripancreatic fat density, suggesting an inflammatory process. Endoscopic ultrasonography-guided fine-needle aspiration of the pancreatic head lesion revealed only mild fibrosis without IgG4-positive plasma cells, and the serum IgG4 level was in the normal range. Under a presumed diagnosis of treatment-refractory chronic pancreatitis, subtotal stomach-preserving pancreaticoduodenectomy was performed. Histopathological examination indicated moderate to marked inflammation in the duodenal submucosa and deeper layers, characterized by storiform fibrosis and abundant IgG4-positive plasma cell infiltration. In contrast, the pancreatic parenchyma showed no significant inflammatory changes. These findings supported a diagnosis of IgG4-related disease predominantly involving the duodenum. IgG4-related lesions of the small intestine, particularly those localized to the duodenum, are rare and often present with non-specific clinical, endoscopic, and imaging features, making preoperative diagnosis challenging. This case highlights an unusual manifestation of IgG4-related disease and shows the importance of considering this entity in cases of unexplained duodenal inflammation, as well as the essential role of histopathological evaluation in establishing a definitive diagnosis.

Background: This study evaluates short-term outcomes of robot-assisted (Rt) and laparoscopic (Lap) intracorporeal anastomosis (IA) in colon resection using an exploratory single-center retrospective cohort and a systematic review and meta-analysis conducted in accordance with PRISMA guidelines. Methods: Patients with colon cancer who underwent laparoscopic or robotic surgery at our institution from 2015 to 2024 were retrospectively enrolled. Additionally, a meta-analysis was conducted using PubMed, Web of Science, Scopus, and the Cochrane Library to identify studies comparing Rt-IA and Lap-IA. Short-term outcomes were statistically compared between the two groups. Results: A total of 77 patients were included (Rt-IA 26, Lap-IA 51). Intraoperative blood loss was significantly lower in the Rt-IA group (median, 5 mL vs. 10 mL; p = 0.001). No statistically significant differences were detected in major postoperative complications or most recovery-related outcomes. For the meta-analysis, 11 studies (1 prospective and 10 retrospective) met the inclusion criteria. After adding our institutional data, the pooled analysis showed that operative time was significantly longer in the Rt-IA group (MD, 54.02 min; 95% CI, 34.18–73.86; I2 = 95.4%), whereas the Rt-IA group demonstrated significantly less blood loss (MD, −14.33 mL; 95% CI: −27.04 to −1.63; I2 = 19.3%). Conclusions: The results of our institutional analysis together with meta-analysis suggest that Rt-IA may be associated with longer operative time but slightly lower blood loss than Lap-IA. These findings suggest that Rt-IA may be a feasible alternative to Lap-IA; however, the results should be interpreted with caution given the limitations of the available evidence.

Background: Anastomotic leakage is one of the most severe and critical complications of laparoscopic surgery for colorectal cancer. However, definitive preoperative predictors of anastomotic leakage remain elusive. With the ageing of society, the number of colorectal cancer patients with arteriosclerotic disease in Japan is increasing. This study was performed to evaluate the correlation between preoperative arteriosclerosis and anastomotic leakage. Methods: In total, 98 patients undergoing laparoscopic surgery for colorectal cancer with reconstruction using the double-stapling technique without diversion of the stoma were enrolled in the study. Preoperative assessment of arteriosclerotic disease was performed by abdominal computed tomography. The calcification volume percentage of the aorta between the level of the celiac artery root and aortic bifurcation was calculated using ZIOstation2 software, and the relationship between arteriosclerosis and anastomotic leakage was analysed. Results: Among 98 cases, anastomotic leakage was observed in 16 (16.3%). The median calcification volume percentage (range) was 2.35% (0-40.3%). Age, male sex, hypertension, dissection number, estimated glomerular filtration rate and tumour location were correlated with anastomotic leakage on statistical analysis. Statistical analysis showed that calcification volume percentage was one of the robust risk factors for anastomotic leakage (odds ratio: 1.09, 95% confidence interval: 1.03-1.17, P < 0.01). Conclusions: Calcification of the abdominal aorta may be a promising predictor of AL after laparoscopic surgery for colorectal cancer reconstruction using the double-stapling technique.

Background: This study aims to elucidate the effects of renin-angiotensin system inhibitors (RASIs) on renal function throughout the stoma period in patients undergoing ileostomy formation and subsequent stoma closure following rectal cancer surgery. Methods: In this single-center retrospective study, patients who underwent rectal resection with temporary ileostomy between January 2010 and December 2020 were divided into two groups based on RASI use. Renal function was assessed using the estimated glomerular filtration rate (eGFR) at pre-surgery (T0), a month post-surgery (T1), and pre-stoma closure (T2). The eGFR, its change at each point, and the chronic kidney disease (CKD) classification were used to assess early and subsequent changes in renal function. Results: Nineteen of 101 patients were using RASI. The RASI and control groups both exhibited eGFR decline at T1, with the former group showing a significantly lower median eGFR (56.2 mL/min/1.73m2 vs. 68.7; p = 0.007). Although a slight improvement in eGFR was observed, neither group returned to baseline levels by T2. The RASI group showed lower eGFR values at both time points. Multivariate analyses indicated that RASI use was a significant risk factor for renal function impairment in terms of a worse CKD classification at T1 (OR: 9.099; 95% CI: 3.015–27.460; p < 0.001). Conclusion: Our findings suggest that the use of RASIs is associated with early perioperative renal function impairment in patients undergoing ileostomy and stoma closure, with relatively slow recovery. These results indicate the impact of RASIs on eGFR and the importance of careful renal function management.

Colorectal mucinous adenocarcinoma (MAC) is one of the most lethal histological types of colorectal cancer, and its mechanism of development is not well understood. In this study, we aimed to clarify the molecular characteristics of MAC via in silico analysis using The Cancer Genome Atlas database. The expression of genes on chromosome 20q (Chr20q) was negatively associated with the expression of MUC2, which is a key molecule that can be used to distinguish between MAC and nonmucinous adenocarcinoma (NMAC). This was consistent with a significant difference in copy number alteration of Chr20q between the two histological types. We further identified 475 differentially expressed genes (DEGs) between MAC and NMAC, and some of the Chr20q genes among the DEGs are considered to be pivotal genes used to define MAC. Both in vitro and in vivo analysis showed that simultaneous knockdown of POFUT1 and PLAGL2, both of which are located on Chr20q, promoted MUC2 expression. Moreover, these genes were highly expressed in NMAC but not in MAC according to the results of immunohistological studies using human samples. In conclusion, POFUT1 and PLAGL2 are considered to be important for defining MAC, and these genes are associated with MUC2 expression.

Background: This study aimed to analyse the perioperative results from a national dataset of rectal cancer resections in elderly patients. Methods: The clinical records of patients undergoing rectal cancer surgery between 2012 and 2014 were retrieved from the Japanese National Clinical Database and analysed retrospectively. Patients were categorized according to age and those 80 years or older were defined as elderly. Subgroups were also defined according to the surgical approach (laparoscopy versus open surgery). The short-term outcomes, including mortality, anastomotic leak, surgical site infections and medical complications were compared between subgroups. Results: Of 56 175 patients undergoing rectal cancer surgery, some 6717 patients were elderly and laparoscopy was performed in 46.8 per cent of the sample. When comparing laparoscopy and open surgery in elderly patients, the operative mortality rate (1.5 versus 2.8 per cent; P<0.001), the incidence of anastomotic leakage (5.2 versus 6.5 per cent; P=0.026), surgical site infections (6.0 versus 8.0 per cent; P=0.001), pneumonia (1.4 versus 2.5 per cent; P=0.001), renal failure (0.7 versus 1.3 per cent; P=0.016) and cardiac events (0.3 versus 0.8 per cent; P=0.008) were lower for laparoscopy than for open surgery. The overall complication rate in elderly patients (19.5 per cent) was comparable to that in the younger group (P=0.07). However, incidence of systemic complications was significantly higher in elderly than in younger patients (all P<0.001). Conclusion: Laparoscopy was safe and feasible in elderly patients compared with open surgery. However, the rates of systemic complications were significantly higher than in younger patients.

Tumor spread through air spaces (STAS) is a histological feature associated with poor prognosis in primary lung cancer, but its relevance in colorectal cancer (CRC) pulmonary metastases remains unclear. This study evaluated the prognostic impact of STAS in CRC pulmonary metastases and its association with histologic features of the primary tumor. A total of 124 patients who underwent pulmonary resection for CRC metastases were retrospectively analyzed. Quantitative STAS parameters, including density and maximum spread distance, were assessed histologically. Survival outcomes were analyzed using Kaplan–Meier and Cox proportional hazards models, and logistic regression identified predictors of STAS. STAS was present in 33.1% of patients and was associated with significantly shorter 5-year recurrence-free survival (18.7% vs. 53.0%, p = 0.002) and overall survival (p = 0.001). Quantitative STAS metrics correlated with intrathoracic recurrence. Patients with high tumor budding grade had a significantly higher STAS-positive rate than those with none or low grade (60% vs. 31.2%, p = 0.036). Tumor budding independently predicted STAS (odds ratio: 3.19, 95% confidence interval: 1.05–9.69, p = 0.040). STAS independently predicted poor prognosis, particularly intrathoracic recurrence. Quantitative STAS assessment enhanced prognostic precision, and tumor budding grade may serve as a preoperative marker for predicting STAS.