須田 康一

BACKGROUND: The use of the hinotori™ Surgical System (hinotori) in distal pancreatectomy (DP) is new compared to the da Vinci™ Surgical System (DVSS). The hinotori is equipped with mechanisms distinct from those of DVSS, and comprehensive reports detailing the surgical techniques and outcomes associated with hinotori in DP (hinotori-DP) are lacking. This study aimed to compare the outcomes of DP using the hinotori and DVSS (Xi system), focusing on differences in settings and techniques between the two methods. METHODS: This study retrospectively investigated consecutive patients who underwent robotic DP from April 2010 (the introduction of robotic DP at our institute) to July 2024. The analysis excluded patients who underwent spleen-preserving procedures or procedures performed using robotic platform other than hinotori or daVinci Xi. The hinotori-DP cases were compared with those performed using DVSS (DVSS-DP). The techniques used in hinotori-DP were examined in more detail. RESULTS: A total of 75 robotic DP cases (11 with hinotori and 64 with DVSS) were analyzed in this study. Different port configurations and techniques, including a lesser curvature approach, were used in the hinotori-DP compared to DVSS-DP. The operation time was relatively shorter in the hinotori-DP group (299 vs. 366 min, p = 0.095), and the postoperative complication rates were comparable (pancreatic fistula: 27 % vs. 30 %, p = 0.871; Clavien-Dindo Grade ≥3a complications: 18 % vs. 19 %, p = 0.964) between the two groups. CONCLUSION: The hinotori-DP can be safely performed by focusing on the unique characteristics of the hinotori surgical system.

Colorectal cancer (CRC) is well characterized in terms of genetic mutations and the mechanisms by which they contribute to carcinogenesis. Mutations in APC, TP53, and KRAS are common in CRC, indicating key roles for these genes in tumor development and progression. However, for certain tumors with low frequencies of these mutations that are defined by tumor location and molecular phenotypes, a carcinogenic mechanism dependent on BRAF mutations has been proposed. We here analyzed targeted sequence data linked to clinical information for CRC, focusing on tumors with a high tumor mutation burden (TMB) in order to identify the characteristics of associated mutations, their relations to clinical features, and the mechanisms of carcinogenesis in tumors lacking the major driver oncogenes. Analysis of overall mutation frequencies confirmed that APC, TP53, and KRAS mutations were the most prevalent in our cohort. Compared with other tumors, TMB-high tumors were more frequent on the right side of the colon, had lower KRAS and higher BRAF mutation frequencies as well as a higher microsatellite instability (MSI) score, and showed a greater contribution of a mutational signature associated with MSI. Ranking of variant allele frequencies to identify genes that play a role early in carcinogenesis suggested that mutations in genes related to the DNA damage response (such as ATM and POLE) and to MSI (such as MSH2 and MSH6) may precede BRAF mutations associated with activation of the serrated pathway in TMB-high tumors. Our results thus indicate that TMB-high tumors suggest that mutations of genes related to mismatch repair and the DNA damage response may contribute to activation of the serrated pathway in CRC.

BACKGROUND: In the field of abdominal surgery, including colorectal cancer surgery, robotic surgery has become widespread, and the introduction of new robotic platforms is increasing. As a result, the incidence of subcutaneous emphysema (SE) as a postoperative complication has increased; however, the causes, grade, and perioperative course of SE have not been definitively examined. Therefore, we aimed to evaluate potential risk factors of SE after robotic colorectal cancer surgery. METHODS: Between November 2022 and March 2024, 244 consecutive patients who underwent robotic colorectal cancer surgery using the da Vinci Xi (n = 190) or the hinotori™ platform (n = 54) were retrospectively analyzed. Risk factors associated with postoperative SE were assessed by multivariate analysis using logistic regression models. Moreover, the grade of SE and its perioperative course were investigated based on the two robotic platforms. RESULTS: Postoperative SE was observed in 95 patients (38.9%). Nine patients (3.7%) had severe SE. The risk factors for SE were female sex, older age (≥ 80 years), and maximum intraabdominal pressure (max IAP) with CO2 insufflation > 10 mmHg (odds ratio [95% confidence interval]: 1.981 [1.105-3.552], p = 0.022; 2.765 [1.310-5.835], p = 0.008; and 13.249 [1.227-143.020], p = 0.033, respectively). Additionally, the incidence of SE when using the hinotori™ platform was significantly lower than when using the da Vinci Xi platform (0.302 [0.135-0.667], p = 0.004). CONCLUSIONS: Max IAP with CO2 > 10 mmHg was associated with SE during robotic colorectal cancer surgery. Compared with the use of da Vinci Xi, the use of hinotori™ was associated with fewer incidences of postoperative SE, especially in females and older patients (≥ 80 years).

Pelvic arteriovenous malformation (AVM) is a rare vascular condition with diverse clinical manifestations. Treatment-related decision-making is difficult for concurrent AVMs and colon cancer. Interventional radiology is effective for colon cancer patients with pelvic AVM. Herein, a 77-year-old man presented with fatigue. Computed tomography revealed thickening of the sigmoid colon wall without lymph node swelling or distant metastasis, confirming irregularly dilated pelvic blood vessels. Preoperative transcatheter embolization of the AVM was initially performed. Then, laparoscopic sigmoidectomy was performed without complications following confirmation of AVM shrinkage via computed tomography. The patient was discharged without complications. Thus, preoperative pelvic AVM embolization in patients with sigmoid colon cancer may facilitate safe minimally invasive surgery.

Background: In Japan, the hinotori™ surgical robot system (Medicaroid Corporation, Kobe, Japan) was approved for gastrointestinal surgeries in October 2022. This report details our initial experience performing liver resection using the hinotori™ system. Methods: Ten patients, who were assessed as cases that would benefit from the robot-assisted procedure, underwent liver resections using the hinotori™ system at Fujita Health University, Okazaki Medical Center, between August 2023 and October 2024. The backgrounds (patient, tumor, and liver function conditions, along with types of liver resections and previous surgical procedures) and short-term outcomes (operation time, blood loss, postoperative complications, open conversion, length of hospital stay, and mortality) of the cases were evaluated. Results: Eight cases of partial liver resection, one extended left medial sectionectomy, and one left hemi-hepatectomy were performed. Six cases of hepatocellular carcinomas, three cases of liver metastases, and one case of hepatolithiasis were included. There were seven male and three female patients with a median age of 70 years. Three physical status class III and seven class II patients were included. The median body mass index was 24. Five patients had previous upper abdominal surgical histories and five patients had liver cirrhosis. The median operation time was 419.5 min, and the median intraoperative blood loss was 276 mL. An open conversion in one hepatocellular carcinoma case was carried out due to bleeding from collateral vessels in the round ligament. The median length of hospital stay was 7.5 days. A grade IIIa complication (delayed bile leakage) was developed in one case. All patients with tumors underwent R0 resection. There were no cases of mortality. Conclusions: Liver resection using the hinotori™ system was feasibly performed. This study reports the first global use of the hinotori™ system for liver resection.

BACKGROUND: Postoperative pancreatic fistula (POPF) is one of the potentially serious complications after gastrectomy for gastric cancer (GC). Drain amylase level is a predictor of POPF in open and laparoscopic gastrectomy, but no study has focused on minimally invasive surgery (MIS), including robotic gastrectomy (RG). This study assesses the effect of drain amylase levels for POPF in MIS and develop a prediction model in the MIS era. METHODS: This single-institutional retrospective study, conducted from January 2011 to December 2021, included 1,353 who underwent standard MIS for GC. We placed a drain in all patients undergoing MIS gastrectomy and measured the drain amylase level on the first postoperative day (D1Amy). The predictive accuracy of D1Amy for POPF was assessed. Additionally, the entire cohort was randomly categorized into the training (1,048 patients) and validation sets (305 patients) to establish the nomogram. RESULTS: Of the 1353 patients, 530 underwent a robotic approach. POPF and intraabdominal infectious complications of Clavien-Dindo classification grade ≥ II were observed in 80 (5.9%) and 145 (10.7%) patients, respectively. Median D1Amy was 812 U/L. The receiver operating characteristic analysis of D1Amy for POPF revealed an area under the curve (AUC) of 0.888. Multivariate analysis revealed age, tumor location, splenectomy, and D1Amy as significant risk factors for POPF. The AUC of the nomogram was 0.8960, validated with AUC of 0.9259. CONCLUSIONS: We revealed the utility of D1Amy in predicting POPF in MIS gastrectomy. Furthermore, the nomogram, incorporating D1Amy and other clinical factors, was additionally used as a predictive model for POPF.

AIM: Malnutrition is reportedly associated with the development of delirium. As dental health is essential for nutritional intake, tooth loss may be a risk factor for the development of delirium. This study aimed to investigate the relationship between postoperative delirium and the number of remaining teeth in patients undergoing gastrointestinal surgery. METHODS: This retrospective study included 453 consecutive patients aged ≥65 years who underwent programmed gastrointestinal cancer surgery under general anesthesia at the Department of Surgery, Fujita Health University Hospital, between January 2022 and December 2022. Background factors were prepared between the participants with and without dental intervention. In the dental intervention group, associations between background and surgical factors and the presence of postoperative delirium were explored. Factors with significant associations with postoperative delirium in the univariate analysis were subjected to logistic regression analysis to determine their association with the number of remaining teeth. RESULTS: Overall, 189 participants underwent postoperative management. They had a significantly lower Prognostic Nutritional Index and higher cognitive decline than the 264 patients who underwent no dental intervention during this period. However, no significant difference was observed in the incidence of postoperative delirium between the two groups. In the dental intervention group, logistic regression analyses revealed that postoperative complications and the number of remaining teeth were significantly associated with postoperative delirium development. CONCLUSION: The results revealed that a decrease in the number of remaining teeth is associated with postoperative delirium. The cause of this is not clear, but it is thought to be related to brain fragility. Geriatr Gerontol Int 2024; ••: ••-••.

BACKGROUND: Advanced gastric cancer with gastric outlet obstruction (GOO) causes malnutrition and medication adherence issues, leading to a poor prognosis. We developed a novel multimodal, less invasive treatment approach for gastric cancer patients with symptomatic GOO: laparoscopic stomach-partitioning gastrojejunostomy (LSPGJ) combined with neoadjuvant chemotherapy (NAC), followed by minimally invasive gastrectomy with reuse of gastrojejunostomy. This study is a retrospective analysis of the safety and feasibility of our treatment strategy. METHODS: In this single-institution retrospective study, we enrolled 54 patients (NAC group, n = 26; upfront gastrectomy group, n = 28) who achieved R0 resection through a minimally invasive approach between 2007 and 2020 and evaluated their short- and long-term outcomes. RESULTS: After LSPGJ, the Gastric Outlet Obstruction Scoring System score significantly improved (p < 0.001). The median relative dose intensity of NAC was 88.2%. Regarding short-term outcomes, there were no differences in postoperative complications, length of postsurgical hospital stay, and adjuvant chemotherapy administration. Although overall survival and relapse-free survival showed trends toward improvement in the NAC group, these differences were not statistically significant. The cumulative incidence curve for recurrence in the NAC group was significantly lower than that of the upfront gastrectomy group (p = 0.041). Recurrence and hematogenous metastasis were significantly lower in the NAC group (p = 0.031 and 0.041, respectively) than in the upfront gastrectomy group. A forest plot revealed that NAC yielded favorable outcomes, particularly for patients with a body mass index (BMI) < 18.5 kg/m2, cT4, or cN1. CONCLUSIONS: LSPGJ combined with NAC followed by minimally invasive gastrectomy was a safe and feasible treatment strategy for patients with advanced gastric cancer with symptomatic GOO. This procedure may contribute to the early recovery of oral intake and help maintain NAC dose intensity, potentially improving prognosis, particularly for patients with low BMI and advanced-stage disease.

BACKGROUND: Telesurgery has been made increasingly possible with the advancements in robotic surgical platforms and network connectivity. However, long-distance transnational complex robotic surgeries such as gastrectomy have yet to be attempted. METHODS: Multiple transnational network connections by Science Innovation Network (SINET), Japan Gigabit Network (JGN), and Arterial Research and Education Network in Asia-Pacific (ARENA-PAC) were established and tested by multiple surgeons in a dry box model. Surgeons' perceptions of the different networks were recorded. Three robotic radical D2 gastrectomies in live porcine models were performed at a hospital in Toyoake, Japan, by a surgical team in a hospital in Singapore ~5000 km away, using the hinotori Surgical Robot System (Medicaroid Corporation). RESULTS: The live porcine robotic gastrectomies were all completed in under 205 min with no intraoperative complications. From the different networks that were tested, the differences in latency ranged from 107 to 132 ms and did not translate to any significant differences in surgeon timings and perceptions. CONCLUSIONS: Transnational telesurgical radical D2 gastrectomy is feasible in a porcine model. There is no appreciable difference between surgeon performance and perception with network latencies of 107-132 ms. Long-range telesurgery as clinical practice may become possible in the future.

BACKGROUND: Posthepatectomy liver failure (PHLF) remains a severe complication after liver resection. This retrospective study investigated the correlation of three hepatic functional tests and whether 99mTc-galactosyl human serum albumin (99mTc-GSA) scintigraphy and modified albumin-bilirubin (ALBI) score are useful for predicting PHLF. METHODS: This retrospective cohort study included 413 consecutive patients undergoing hepatectomies between January 2017 and December 2020. To evaluate preoperative hepatic functional reserve, modified ALBI grade, indocyanine green clearance (ICG-R15), and 99mTc-GSA scintigraphy (LHL15) were examined before scheduled hepatectomy. Based on a retrospective chart review, multivariable logistic regression analysis adjusted for confounding factors was performed to confirm that mALBI, ICG-R15, and LHL15 are independent risk factors for PHLF. RESULTS: ICG-R15 and LHL15 were moderately correlated (r =  - 0.61) but this correlation weakened when ICG-R15 was about ≥ 20. Weak correlations were observed between LHL15 and ALBI score (r =  - 0.269) and ALBI score and ICG-R15 (r = 0.339). Of 413 patients, 66 (19%) developed PHLF (20 grade A, 44 grade B, 2 grade C). Multivariable logistic regression analyses, major hepatectomy (P < 0.001), mALBI grade (P = 0.01), ICG-R15 (P < 0.001), and Esophagogastric varices (P = 0.007) were significant independent risk factors for PHLF. Subgroup analysis showed that ICG-R15 < 19, major hepatectomy, and mALBI grade and ICG-R15 ≥ 19, major hepatectomy, LHL15, and Esophagogastric varices were significant independent risk factors for PHLF (P = 0.033, 0.017, 0.02, 0.02, and 0.001, respectively). CONCLUSION: LHL15, the assessment of Esophagogastric varices, and mALBI grade are complementary to ICG-R15 for predicting PHLF risk.

BACKGROUND/PURPOSE: Gut microbiota status after pancreaticoduodenectomy (PD) is unclear, and postoperative fatty liver is an important complication after PD. This study evaluated the relationship between postoperative fatty liver and gut microbiota after PD. METHODS: Fecal samples were collected from patients who had undergone PD and remained stable after 6 months of follow-up. A comprehensive bacterial analysis using 16S rRNA gene amplicon sequencing was performed. The results were compared with those of 85 healthy volunteers. The association between perioperative factors, gut microbiota, and development of fatty liver was investigated. RESULTS: Twenty-four patients after PD, including 10 in the fatty liver (FL) group and 14 in the normal liver (NL) group were investigated. The β-diversity of the gut microbiota was significantly different between the healthy volunteers and patients after PD, with more Escherichia coli and Streptococcus gallolyticus and less Bifidobacterium catenulatum and Faecalibacterium prausnitzii in the patients with PD. Lactobacillus gasseri was significantly less abundant in the FL group than in the healthy volunteers, although this change was not observed in the NL group. CONCLUSIONS: The gut microbiota of patients after PD was in dysbiosis at postoperative ≥6 months. Development of fatty liver might be associated with significant differences in gut microbiota.

Subtotal colectomy is often performed on patients with synchronous colorectal cancer. However, compared with colorectal anastomosis, ileorectal anastomosis with subtotal colectomy is more likely to result in bowel dysfunction. The Deloyers procedure is useful in preserving bowel function in a patient with synchronous colorectal cancer. An 87-year-old man presented with bloody stool. Colonoscopy showed masses in the cecum, transverse colon, rectosigmoid, and rectum above the peritoneal reflection. Computed tomography scan revealed no evidence of regional lymph node swelling and distant metastasis. Therefore, robot-assisted low anterior resection, laparoscopic extended left hemicolectomy, laparoscopic cecal resection, and diverting ileostomy were performed. The patient was discharged from the hospital without complications. There was no recurrence, and the patient did not have complaints such as urgency, fecal incontinence, and excretory dysfunction. Hence, minimally invasive coloproctectomy using the Deloyers procedure can be safe and useful in preserving postoperative bowel function in elderly patients.

BACKGROUND: Nonresectable gastric cancer develops rapidly; thus, monitoring disease progression especially in patients receiving nivolumab as late-line therapy is important. Biomarkers may facilitate the evaluation of nivolumab treatment response. Herein, we assessed the utility of serum-based inflammatory indicators for evaluating tumor response to nivolumab. METHODS: This multicenter retrospective cohort study included 111 patients treated with nivolumab monotherapy for nonresectable advanced or recurrent gastric cancer from October 2017 to October 2021. We measured changes in the C-reactive protein (CRP)-to-albumin ratio (CAR), platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) in serum from baseline to after the fourth administration of nivolumab. Furthermore, we calculated the area under the receiver operating characteristic curves (AUC ROCs) for CAR, PLR, and NLR to identify the optimal cutoff values for treatment response. We also investigated the relationship between clinicopathologic factors and disease control (complete response, partial response, and stable disease) using the chi-squared test. RESULTS: The overall response rate (complete and partial response) was 11.7%, and the disease control rate was 44.1%. The median overall survival (OS) was 14.0 (95% CI 10.7‒19.2) months, and the median progression-free survival (PFS) was 4.1 (95% CI 3.0‒5.9) months. The AUC ROCs for CAR, PLR, and NLR before nivolumab monotherapy for patients with progressive disease (PD) were 0.574 (95% CI, 0.461‒0.687), 0.528 (95% CI, 0.418‒0.637), and 0.511 (95% CI, 0.401‒0.620), respectively. The values for changes in CAR, PLR, and NLR were 0.766 (95% CI, 0.666‒0.865), 0.707 (95% CI, 0.607‒0.807), and 0.660 (95% CI 0.556‒0.765), respectively. The cutoff values for the treatment response were 3.0, 1.3, and 1.4 for CAR, PLR, and NLR, respectively. The PFS and OS were significantly longer when the treatment response values for changes in CAR, PLR, and NLR were below these cutoff values (CAR: OS, p < 0.0001 and PFS, p < 0.0001; PLR: OS, p = 0.0289 and PFS, p = 0.0302; and NLR: OS, p = 0.0077 and PFS, p = 0.0044). CONCLUSIONS: Measurement of the changes in CAR, PLR, and NLR could provide a simple, prompt, noninvasive method to evaluate response to nivolumab monotherapy. TRIAL REGISTRATION: This study is registered with number K2023006.

Abstract Background The advantages of robot‐assisted minimally invasive esophagectomy (RA‐MIE) over conventional minimally invasive esophagectomy (C‐MIE) are unknown. This nationwide large‐scale study aimed to compare surgical outcomes between RA‐MIE and C‐MIE using rigorous propensity score methods, including detailed covariates and relevant outcomes. Methods This Japanese nationwide retrospective cohort study included RA‐MIE or C‐MIE for esophageal malignant tumors performed between October 2018 and December 2019 and registered in the Japanese National Clinical Database. The primary outcome measure was postoperative complications classified as Clavien–Dindo Grade IIIa or higher. Propensity score matching was performed to create a balanced covariate distribution between the two groups. Results After propensity score matching, 1092 patients were selected. The RA‐MIE group had a significantly longer operation time and greater blood loss than the C‐MIE group (565 vs. 477 min and 120 vs. 90 mL). Furthermore, the R0 resection rate was lower in the RA‐MIE group than in the C‐MIE group (95.1% vs. 97.8%). The RA‐MIE and C‐MIE groups had no differences regarding overall complications ≥ Grade IIIa (22.0% vs. 20.3%, p = 0.52), 30‐day mortality rates (0.4% vs. 0.5%), and operative mortality rates (0.7% vs. 0.7%). Deep SSI was less frequent (2.7% vs. 6.0%) and pulmonary embolism was more frequent (2.4% vs. 0.5%) in the RA‐MIE group than in the C‐MIE group. Conclusions In the initial phase of implementation, RA‐MIE and C‐MIE demonstrated comparable morbidity rates when performed by skilled board‐certified endoscopic surgeons.

BACKGROUND: Adenosquamous carcinoma of the pancreas (ASCP) accounts for only 1-4% of all pancreatic exocrine cancers and has a particularly poor prognosis. The efficacy of chemotherapy for ASCP remains unknown because of the small number of cases, and few studies have evaluated conversion-intended chemotherapy. CASE PRESENTATION: A 76-year-old woman was referred to our hospital because of epigastric pain and nausea. A preoperative contrast-enhanced multidetector row computed tomography (MDCT) scan revealed a 17 × 17 mm low-density tumor with an ill-defined margin at the arterial phase in the pancreatic head. The tumor involved the common hepatic artery, left hepatic artery bifurcated from the common hepatic artery, and gastroduodenal artery, and was in contact with the portal vein. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed an uptake in the pancreatic head but no evidence of distant metastasis. The tumor was diagnosed as an adenocarcinoma of the pancreatic head and staged unresectable because the common and left hepatic arteries were involved. Hence, the patient underwent seven courses of conversion-intended chemotherapy using gemcitabine and nab-paclitaxel for pancreatic ductal adenocarcinoma over 7 months. After chemotherapy, the tumor shrank to 10 × 10 mm on contrast-enhanced MDCT. Consequently, the boundary between the tumor and major vessels of the common and left hepatic arteries and the portal vein became clear, and the involvement of the arteries with the tumor was evaluated to be released. The contact of the tumor to the portal vein also reduced to less than half the circumference of the portal vein. FDG-PET showed decreased accumulation in the tumor. Hence, the tumor was judged resectable, and pancreaticoduodenectomy was performed. The tumor and major blood vessels were easily dissected and R0 resection was achieved. The patient experienced no major complications and was discharged on postoperative day 28. The tumor was revealed as ASCP via pathological examination. The patient is alive and recurrence-free seven months after surgery. This is the first report of successful R0 resection for an initially unresectable ASCP following conversion-intended chemotherapy using gemcitabine and nab-paclitaxel regimen. CONCLUSIONS: Conversion-intended chemotherapy using gemcitabine and nab-paclitaxel regimen may be effective for ASCP.

BACKGROUND: This study aimed to investigate the laparoscopic gastrectomy (LG) performance of non-Endoscopic Surgical Skill Qualification System (ESSQS)-qualified surgeons under the ESSQS-qualified surgeon guidance and compare oncological outcomes of gastric cancer to LG performed by the ESSQS-qualified surgeons. METHODS: This study enrolled 1,030 patients diagnosed with both clinical and pathological stage ≤ III gastric cancer and undergoing LG from January 2009 to June 2019. ESSQS-qualified surgeons served as the operator or the instructive assistant in all LG procedures involving them. A propensity score-matched analysis was used to retrospectively compare the long-term outcomes between the ESSQS-qualified and non-ESSQS-qualified surgeons. RESULTS: Each group included 315 pairs after propensity score matching. The 3-year recurrence-free survival rates were 84.4% and 81.7% in the non-ESSQS and ESSQS groups, respectively. The difference was 2.7% (95% confidence interval: - 3.20%-8.44%, P < 0.001), and the non-ESSQS group statistically demonstrated noninferiority as the lower 95% confidence limit was greater than the prespecified margin of -10%, indicating the achieved primary endpoint. No significant differences in 5-year recurrence-free survival (non-ESSQS: 78.5% vs. ESSQS: 77.4%, P = 0.627) and 5-year overall survival (non-ESSQS: 80.9% vs. ESSQS: 79.3%, P = 0.475) were found between the two groups. The oncological outcomes stratified according to the presence of pathological stage I, II, and III disease did not significantly differ between the two groups. CONCLUSIONS: LG performed by non-ESSQS-qualified surgeons achieved comparable oncological outcomes to the ESSQS-qualified surgeons, as long as ESSQS-qualified surgeons provided intraoperative instructions, in a high-volume center.

BACKGROUND: The optimal approach for the safe implementation and education of robotic pancreaticoduodenectomy (RPD) remains unclear. Prolonged operation time may cause surgeon fatigue and result in perioperative complications. To solve this issue, our department adopted task division by the console surgeon turnover between resection and reconstruction in 2022. METHODS: This study retrospectively investigated consecutive patients who underwent RPD from November 2009 (initial introduction of RPD) to December 2023. The analysis excluded patients who underwent concomitant resection of other organs. The cases performed by a single console surgeon (single approach) were compared with those performed by two or more console surgeons (multiple approach). RESULTS: This study analyzed 85 consecutive RPD cases, including 51 with the single approach and 34 with the multiple approach. The operation time was significantly shorter (832 vs. 618 min, p < 0.001), and the postoperative major complication was less frequent (45% vs. 12%, p = 0.003) in the multiple approach group, although less experienced surgeons performed the multiple approach (number of RPD experiences: 19 cases vs. 5 cases, p < 0.001). The console surgeon turnover between the resection and reconstruction resulted in a safe pancreatojejunostomy performed by the less experienced surgeon (number of pancreatic reconstruction experiences: 6.5 vs. 14 cases, p = 0.010). Surgeons who started RPD with a multiple approach observed a reduction in surgical time and a lower incidence of complications earlier than those who started with a single approach. CONCLUSION: Task division during the early introduction phase of RPD using the multiple approach demonstrated potential contributions to improved surgical outcomes and enhanced educational benefits.

OBJECTIVE: The risk factors for residual liver recurrence after resection of colorectal cancer liver metastases were analyzed separately for synchronous and metachronous metastases. METHODS: This retrospective study included 236 patients (139 with synchronous and 97 with metachronous lesions) who underwent initial surgery for colorectal cancer liver metastases from April 2010 to December 2021 at the Fujita Health University Hospital. We performed univariate and multivariate analyses of risk factors for recurrence based on clinical background. RESULTS: Univariate analysis of synchronous liver metastases identified three risk factors: positive lymph nodes (p = 0.018, HR = 2.067), ≥3 liver metastases (p < 0.001, HR = 2.382), and use of adjuvant chemotherapy (p = 0.013, HR = 0.560). Multivariate analysis identified the same three factors. For metachronous liver metastases, univariate and multivariate analysis identified ≥3 liver metastases as a risk factor (p = 0.002, HR = 2.988); however, use of adjuvant chemotherapy after hepatic resection was not associated with a lower risk of recurrence for metachronous lesions. Inverse probability of treatment weighting analysis of patients with these lesions with or without adjuvant chemotherapy after primary resection showed that patients with metachronous liver metastases who did not receive this treatment had fewer recurrences when adjuvant therapy was administered after subsequent liver resection, although the difference was not significant. Patients who received adjuvant chemotherapy after hepatic resection had less recurrence but less benefit from this treatment. CONCLUSION: Risk factors for liver recurrence after resection of synchronous liver metastases were positive lymph nodes, ≥3 liver metastases, and no postoperative adjuvant chemotherapy. Adjuvant chemotherapy is recommended after hepatic resection of synchronous liver metastases.

Concurrent direct and indirect inguinal, femoral, and obturator hernias are rare. This case report describes a rare case treated using the laparoscopic approach. A 68-year-old female patient presented with a moving left inguinal lump and pain. Physical examination and abdominal computed tomography scan revealed the coexistence of a left inguinal hernia or Nuck canal hydrocele and a left femoral hernia. The patient underwent laparoscopic transabdominal preperitoneal repair, and all four orifices were covered with one mesh. The patient was discharged on the second postoperative day without any complications. The concurrent presence of four hernias on the same side is rare and has not been previously reported. The laparoscopic approach is useful in such cases because it allows visualization of multiple hernia orifices from the intra-abdominal cavity.

BACKGROUNDS: Pancreatojejunostomy is a technically demanding procedure during robotic pancreaticoduodenectomy (RPD). Modified Blumgart anastomosis (mBA) is a common method for the pancreatojejunostomy; however, the technical details for robotic mBA are not well established. During RPD, we performed a mBA for the pancreatojejunostomy using thread manipulation with gauze and an additional assist port. METHODS: Patients who underwent robotic pancreatoduodenectomy at Fujita Health University from November 2009 to May 2023 were retrospectively investigated, and technical details for the robotic-modified Blumgart anastomosis were demonstrated. RESULTS: Among 78 patients who underwent RPD during the study period, 33 underwent robotic mBA. Postoperative pancreatic fistula (POPF) occurred in six patients (18%). None of the patients suffered POPF Grade C according to the international study group of pancreatic surgery definition. The anastomotic time for mBA was 80 min (54-125 min). CONCLUSION: Robotic mBA resulted in reasonable outcomes. We propose that mBA could be used as one of the standard methods for robotic pancreatojejunosotomy.

BACKGROUND: Although minimally invasive total gastrectomy for gastric cancer is commonly performed, reports regarding late complications are limited. We have made several improvements each time we experienced severe late complications since 2009. This study aimed to evaluate the clinical efficacy of these improved procedures in preventing late complications. METHODS: Between January 2009 and December 2019, 302 patients who underwent laparoscopic or robotic total gastrectomy for gastric cancer were enrolled. The patients were divided into two groups: Period-I (2009-2013, before established standardization of procedure, 166 patients) and Period-II (2014-2019, after established standardization of procedure, 136 patients). The standardized procedure comprised four major steps, including closure of the mesentery defects and diaphragm crus, circumferential fixation of the anastomotic site into the diaphragm, and linearization around the anastomotic site of esophagojejunostomy. The incidence of late complications was retrospectively compared between the two groups. RESULTS: Late overall complications that occurred over 30 days after surgery were observed in 19 (6.3%) patients. In all, 14 of 24 (58.3%) patients admitted due to late intestinal complications eventually required reoperation for treatment. The most frequent complication was nonstenotic outlet obstruction of the distal jejunal limb. The incidence of late overall complications was significantly lower in Period-II than in Period-I (2.9 vs 9.0%, p = 0.030). Intestinal complications were reduced considerably in Period-II. The 3-year cumulative incidence rate of late overall complications was significantly lower in Period-II than in Period-I (0.03 vs 0.10, p = 0.035). Period-I as the only independent risk factor for the development of late intestinal complications. CONCLUSION: Late complications after laparoscopic total gastrectomy sometimes occurred, and more than half of the patients with intestinal complications required reoperation. Our standardized procedure was associated with a lower risk of late intestinal complications after minimally invasive total gastrectomy followed by intracorporeal esophagojejunostomy using linear staplers in a cohort of patients with gastric cancer.

Robotic distal pancreatectomy (RDP) has emerged as a minimally invasive approach to left-sided pancreatic tumors. This study aimed to evaluate the efficacy of the robot-assisted approach (RAA) using a laparoscopic articulating vessel-sealing device (LAVSD) during RDP by comparing it with the pure-robotic approach (PRA). Among 62 patients who underwent RDP between April 2020 and December 2023 at Fujita Health University, 22 underwent RAA (the RAA group). In RAA, console surgeons mainly prepared the surgical fields, and assistant surgeons actively dissected the adipose and connective tissues using LAVSD. The surgical outcomes of these patients were compared with those of 40 consecutive patients who underwent RDP with PRA. In total, 28 males and 34 females with a median age of 71 years were analyzed. The console surgeon's prior experience of performing RDP was similar between the groups (RAA; median, 6 [range, 0-36], PRA; median, 5.5 [range, 0-34] cases). The operation time was significantly shorter in the TST group (median, 300.5 [range, 202-557] vs. 363.5 [range, 230-556] min, p = 0.015). Major complications (Clavien-Dindo ≥ grade 3a) occurred less frequently in the RAA group (4.6% vs. 25.0%, p = 0.028). Although the median postoperative hospital stay was slightly shorter in the RAA group (median, 12 [range, 8-38] vs. 14.5 [8-44] days, p = 0.095), no statistically significant difference was observed. Compared with PRA, RAA using LAVSD is found to be safe and feasible in introducing RDP for operators with little experience.

【目的】胃がん手術後の体重減少は,生活の質の低下など影響をおよぼす重要な課題である.今回,低侵襲胃がん手術後1ヵ月の体組成変化と除脂肪体重減少の要因について検討した.【対象および方法】2021年4月から2022年8月で低侵襲胃がん手術の術前および術後1ヵ月に体組成測定した88例を対象とした.術後1ヵ月の除脂肪体重減少率の中央値(2.4%)以下46例をLow群(以下,L群と略),中央値より大きい42例をHigh群(以下,H群と略)とし比較検討した.また,重回帰分析にて除脂肪体重減少のリスク因子を検討した.【結果】L群,H群の術後1ヵ月の変化は体重-5.4%,-7.1%,体脂肪量-16.3%,-13.9%であった.重回帰分析の結果,術前体脂肪率(p<0.01)が有意な変数として抽出された.【結論】術前体脂肪率低値は,術後1ヵ月の除脂肪体重減少の有意な危険因子であり,術前からの介入を要すると考えられた.(著者抄録)

47歳女性,血便精査の大腸内視鏡検査でS状結腸に粘膜下腫瘤(submucosal tumor:SMT)様隆起に連なる潰瘍病変を認め,HE染色で低分化腺癌と診断された.画像上,S状結腸以外にも骨盤内に多数腫瘤を認め,腫瘍マーカーはCA125が高値であった.免疫染色でCK7(+),CK20(-),Pax-8(+)と判明し,婦人科癌の転移と診断した.審査腹腔鏡を行い,卵巣に異常を伴わない腹膜播種の所見であったため,腹膜癌(高異型度漿液性腺癌)と診断した.化学療法3コース後にdebulking surgeryを実施したところ,卵巣に同様の腺癌を認め,卵巣癌の診断に至った.骨盤内腫瘤を伴う大腸腫瘍では免疫染色を考慮することが有用である.(著者抄録)

Undergoing another surgery after a previous abdominal procedure can sometimes result in significant abdominal adhesions. We present a case of robot-assisted low anterior resection in a patient with rectal cancer who had a urinary reservoir. A 65-year-old male patient underwent robot-assisted total bladder resection and creation of a urinary reservoir for bladder cancer in 2013. He presented with melena. Thus, the findings revealed advanced low rectal cancer. The robot-assisted low anterior resection was performed in 2022. Extensive adhesions were observed in the pelvic space. The indocyanine green function was appropriately used, and the robotic surgery was completed without injury to the urinary reservoir or major complications. The surgical time was 510 min, and the blood loss volume was 15 mL. The patient had been recurrence free for 12 months following the surgery. Robot-assisted surgery can be beneficial for patients with rectal cancer with significant pelvic adhesions.

BACKGROUND: Although the da Vinci™ Surgical System is the most predominantly used surgical robot worldwide, other surgical robots are being developed. The Japanese surgical robot hinotori™ Surgical Robot System was launched and approved for clinical use in Japan in November 2022. We performed the first robotic gastrectomy for gastric cancer using hinotori in the world. Here, we report our initial experience and evaluation of the feasibility and safety of robotic gastrectomy for gastric cancer using hinotori. METHODS: A single-institution retrospective study was conducted. Between November 2022 and October 2023, 24 patients with gastric cancer underwent robotic gastrectomy with hinotori. Five ports, including one for an assistant, were placed in the upper abdomen, and gastric resection with standard lymphadenectomy and intracorporeal reconstruction were performed. The primary endpoint was the postoperative complication rate within 30 days after surgery. The secondary outcomes were surgical outcomes, including intraoperative adverse events, operative time, blood loss, and the number of dissected nodes. RESULTS: Of the 24 patients, 16 (66.7%) were male. The median age and body mass index were 73.5 years and 22.9 kg/m2, respectively. Twenty-three patients (95.8%) had tumors in the middle to lower stomach. Sixteen (66.7%) and seven (29.2%) patients had clinical stage I and II diseases, respectively. Twenty-three (95.8%) patients underwent distal gastrectomy. No patient had postoperative complications of Clavien-Dindo classification IIIa or higher, whereas two (8.3%) had the grade II complications (enteritis and pneumonia). No intraoperative adverse events, including conversion to other approaches, were observed. All patients received R0 resection. The median operative and console times were 400 and 305 min, respectively. The median blood loss was 14.5 mL, and the number of lymph nodes dissected was 51.5. CONCLUSIONS: This study found that robotic gastrectomy with standard lymphadenectomy for gastric cancer using hinotori can be safely performed.

BACKGROUND: This study aimed to determine the safety and feasibility of minimally invasive gastrectomy in patients who underwent preoperative chemotherapy for highly advanced gastric cancer. METHODS: Preoperative chemotherapy was indicated for patients with advanced large tumors (≥ cT3 and ≥ 5 cm) and/or bulky node metastasis (≥ 3 cm × 1 or ≥ 1.5 cm × 2). Between January 2009 and March 2022, 150 patients underwent preoperative chemotherapy followed by gastrectomy with R0 resection, including conversion surgery (robotic, 62; laparoscopic, 88). The outcomes of these patients were retrospectively examined. RESULTS: Among them, 41 and 47 patients had stage IV disease and underwent splenectomy, respectively. Regarding operative outcomes, operative time was 475 min, blood loss was 72 g, morbidity (grade ≥ 3a) rate was 12%, local complication rate was 10.7%, and postoperative hospital stay was 14 days (Interquartile range: 11-18 days). Fifty patients (33.3%) achieved grade ≥ 2 histological responses. Regarding resection types, total/proximal gastrectomy plus splenectomy (29.8%) was associated with significantly higher morbidity than other types (distal gastrectomy, 3.2%; total/proximal gastrectomy, 4.9%; P < 0.001). Specifically, among splenectomy cases, the rate of postoperative complications associated with the laparoscopic approach was significantly higher than that associated with the robotic approach (40.0% vs. 0%, P = 0.009). In the multivariate analysis, splenectomy was an independent risk factor for postoperative complications [odds ratio, 8.574; 95% confidence interval (CI), 2.584-28.443; P < 0.001]. CONCLUSIONS: Minimally invasive gastrectomy following preoperative chemotherapy was feasible and safe for patients with highly advanced gastric cancer. Robotic gastrectomy may improve surgical safety, particularly in the case of total/proximal gastrectomy combined with splenectomy.

BACKGROUND: Hydrocele of the canal of Nuck (HCN) is a rare disease, and its indications for laparoscopic surgery are not well-established. CASE PRESENTATION: A 53-year-old woman was referred to our hospital due to an uncomfortable thumb-sized inguinal mass. Preoperative computed tomography scan and magnetic resonance imaging revealed a hydrocele extending from the abdominal cavity around the left deep inguinal ring via the inguinal canal to the subcutaneous space. The patient was diagnosed with HCN protruding into the abdominal cavity and extending to the subcutaneous space. Laparoscopy can easily access the hydrocele protruding into the abdominal cavity. Furthermore, laparoscopic hernioplasty can be superior to the anterior approach for females. Hence, laparoscopic surgery was performed. After transecting the round ligament of the uterus, a tense 3-cm hydrocele was dissected with it. In order to approach the hydrocele distal to the deep inguinal ring, the transversalis fascia was incised medially to the inferior epigastric vessels. The subcutaneously connected hydrocele was excised from the incision. Then, the enlarged deep inguinal ring was reinforced using a mesh with the laparoscopic transabdominal preperitoneal approach. The patient was discharged 2 days postoperatively. Laparoscopic resection can be more effective for a hydrocele protruding into the abdominal cavity as it facilitates an easy access to the hydrocele. Moreover, laparoscopic resection of a hydrocele extending from the inguinal canal to the subcutaneous space via a transversalis fascia incision can be safer, with low risk of injury to the inferior epigastric vessels. The incised transversalis fascia and the enlarged deep inguinal ring due to the HCN were simultaneously repaired with the laparoscopic transabdominal preperitoneal repair. There are two reports on laparoscopic resection via a transversalis fascia incision for HCNs located between the inguinal canal and the subcutaneous space, which does not require intraperitoneal hydrocelectomy. However, this is the first report on laparoscopic resection of large HCNs protruding into the abdominal cavity and extending beyond the inguinal canal into the subcutaneous space via intraperitoneal hydrocelectomy and a transversalis fascia incision. CONCLUSIONS: Laparoscopic surgery with transversalis fascia incision can be useful for HCNs extending from the abdominal cavity to the subcutaneous space.

BACKGROUND: Robotic pancreaticoduodenectomy (RPD) is technically demanding, and 20-50 cases are required to surpass the learning curve. This study aimed to show our experience of 76 cases from the introduction of RPD and report the changes in surgical results owing to the accumulation of cases and optimization of surgical techniques. METHODS: A total of 76 patients who underwent RPD between November 2009 and May 2023 at the Fujita Health University Hospital were divided into three groups: competency (n = 23, Nov 2009-Mar 2020), proficiency (n = 31, Apr 2020-Jun 2022), and mastery (n = 22, Jul 2022-May 2023) phases. In the mastery phase, for the education of new surgeons and maintenance of surgical quality, optimization of the procedure, including hanging maneuver with or without stapling transection of the retropancreatic tissue was implemented. The surgical outcomes were compared between the groups. RESULTS: The mean operation time decreased over time despite of the participation of newly started operators in mastery phase [competency: 921.5 min (IQR 775-996 min) vs. proficiency: 802.8 min (IQR 715-887 min) vs. mastery: 609.2 min (IQR 514-699 min), p < 0.001]. Additionally, Clavien-Dindo ≥ grade IIIa complications decreased from 52.2% in competency phase to 35.5% and 9.1% in proficiency and mastery phases, respectively (p = 0.005). CONCLUSION: Operation time and major complications decreased along the learning curve from the introduction of RPD. In addition, optimization of the procedure, including hanging maneuver of the retropancreatic tissue seemed to be effective in reducing operation time and educating new RPD surgeons.

Pancreatic tumor enucleation is a procedure that can preserve pancreatic function and is sometimes performed using a minimally invasive approach. Recently, a single-port robotic platform called da Vinci SP has been developed. However, the technical details of pancreatic tumor enucleation using da Vinci SP have not been reported to date. We report a male patient in his 70s who underwent robotic SP pancreatic tumor enucleation for a pancreatic neuroendocrine tumor. The dissection between the tumor and pancreatic parenchyma was performed using the double bipolar technique. The operative time was 139 min, and the estimated blood loss was 4 mL. The patient had an uneventful recovery and was discharged on the sixth day after the surgery. Robotic SP pancreatic tumor enucleation appears to be a feasible procedure with lower invasiveness and better cosmesis.