Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Watanabe Yusuke Last modified date:2024.06.26

Assistant Professor / Gastrointestinal Surgery (1) / Kyushu University Hospital

1. Ohtsuka T, Matsunaga T, KImura H, Watanabe Y, Tamura K, ideno N, Aso T, Miyasaka Y, Ueda J, Takahata S, Osoegawa T, Igarashi H, Ito T, Ushijima Y, Ookubo F, Oda Y, Mizumoto K, Tanaka M, Role of pancreatic juice cytology in the preoperative management of intraductal papillary mucinous neoplasm of the pancreas in the era of international consensus guidelines 2012, World J Surg, 38, 11, 2994-3001, 2014.04, BACKGROUND:

Routine endoscopic retrograde pancreatography (ERP) for pancreatic juice cytology (PJC) during management of intraductal papillary mucinous neoplasm (IPMN) is not recommended in the international consensus guidelines 2012. The aim of the present study was to investigate the roles of PJC in relation to the new stratification of clinical findings in the consensus guidelines 2012.


Medical records of 70 consecutive patients who underwent preoperative PJC, subsequent pancreatectomy, and a pathological diagnosis of IPMN were reviewed. Diagnostic ability of PJC to detect malignant lesions was calculated by the stratification of clinical findings.


Forty patients had malignant lesions, including 29 with malignant IPMN, 10 with concomitant pancreatic adenocarcinoma, and one with both. Accuracies of PJC in all 70 patients and in 59 patients with IPMN alone were 77 and 80 %, respectively. The sensitivity and accuracy of PJC in patients with "worrisome features" were 100 and 94 %, respectively. Eight of 11 patients with concomitant pancreatic adenocarcinoma had non-malignant IPMN without risk factors, and 3 significant lesions could be diagnosed only by ERP/PJC. In addition, the management plan based on imaging study changed from observation to resection in two patients who had the single "worrisome feature" of branch duct IPMN and positive PJC results. As a result, PJC altered the management plan in 5 patients.


Pancreatic juice cytology potentially has important roles to determine the adequate treatment choice in patients with IPMNs with "worrisome features," and to detect significant lesions that could not be detected by other imaging modalities.
2. Aso T, Ohtsuka T, Matsunaga T, Kimura H, Watanabe Y, Tamura K, Ideno N, Osoegawa T, Takahata S, Shindo K, Ushijima Y, Aishima S, Oda Y, Ito T, Mizumoto K, Tanaka M, High-risk stigmata of the 2012 international consensus guidelines correlate with the malignant grade of branch duct intraductal papillary mucinous neoplasms of the pancreas, Pancreas, 43, 8, 1239-1243, 2014.04, Objectives: The 2012 international consensus guidelines for themanagementof intraductal papillary mucinous neoplasm (IPMN) of the pancreasstratified patients into 2 clinical categories, “high-risk stigmata” and “worrisomefeatures,” and recommended different therapeutic strategies forthese groups. The aim of this study was to elucidate the significance ofthese categories in terms of predicting malignant IPMNs.Methods: The medical records of 100 consecutive patients whounderwent pancreatectomy for IPMNs were retrospectively reviewed. Seventypatients with branch duct IPMNs (BD-IPMNs) were stratified into 3groups. The relationships between the number of predictive factors and histopathologicgrade were investigated.Results: The prevalence rates of malignant IPMN, invasive carcinoma,and lymph node metastasis in the high-risk group were 80%, 55%, and20%, respectively, with these percentages significantly increasing in a stepwisemanner acc
ording to the number of predictive factors. In contrast,there was no significant correlation between the number of worrisome featuresand grade of malignancy in patients stratified as having worrisomeBD-IPMNs.Conclusions: The number of high-risk stigmata correlated significantlywith the grade of malignancy of BD-IPMNs. The presence of at least 1high-risk stigma in patients with BD-IPMNs indicates a need for pancreatectomywith lymphadenectomy..
3. Kimura H, Ohtsuka T, Matsunaga T, Watanabe Y, Tamura K, Ideno N, Aso T, Miyazaki T, Osoegawa T, Aishima S, Miyasaka Y, Ueda J, Ushijima Y, Igarashi H, Ito T, Takahata S, Oda Y, Mizumoto K, Tanaka M, Predictors and Diagnostic Strategies for Early-Stage Pancreatic Ductal Adenocarcinoma: A Retrospective Study, Pancreas, 44, 7, 1148-1154, 2015.04, OBJECTIVES:

As a strategy to diagnose early-stage pancreatic ductal adenocarcinoma (PDAC) is urgently needed, we aimed to clarify characteristics of early-stage PDAC.


We retrospectively reviewed medical records of 299 consecutive patients who underwent R0 or R1 surgical resection for PDAC between 1994 and 2013 and compared clinical characteristics between patients with early-stage (stages 0-I by Japanese General Rules for Pancreatic Cancer) and advanced-stage (stages II-IV) disease. Diagnostic processes were also analyzed.


Twenty-four patients (8%) had early-stage PDAC (stage 0: 11; stage I: 13). Univariate and multivariate analyses showed that presence or history of intraductal papillary mucinous neoplasm (P

Endoscopic retrograde pancreatography cytology for patients with intraductal papillary mucinous neoplasm or pancreatitis may help diagnose early-stage PDAC. Surveillance of extrapancreatic malignancies might also provide opportunities to detect early-stage PDAC as a second malignancy.
4. Watanabe Y, Ohtsuka T, Matsunaga T, Kimura H, Tamura K, Ideno N, Aso T, Miyasaka Y, Ueda J, Takahata S, Igarashi H, Inoguchi T, Ito T, Tanaka M, Long-term outcomes after total pancreatectomy: special reference to survivors' living conditions and quality of life, World J Surg, 39, 5, 1231-1239, 2015.04, Abstract
Although recent studies have confirmed the safety of total pancreatectomy (TP), appropriate selection of patients for TP has not been well documented. Because patients require lifelong medical treatment and self-management of pancreatic insufficiency after TP, indications for TP should be determined carefully according not only to disease factors but also to the social background of patients. We aimed to clarify long-term outcomes after TP, including the living conditions and quality of life (QoL), of surviving patients.
Medical records of 44 consecutive patients who underwent TP between 1990 and 2013 were reviewed retrospectively; 25 survivors completed cross-sectional clinical surveys and responded to a questionnaire about QoL using Short Form 36v2.
Prevalence of morbidity and mortality after TP was 32 and 5 %, respectively. Postoperative complications occurred more frequently in elderly patients than in young patients (48 vs. 14 %; P = 0.02); however, there was no significant difference in mortality, postoperative hospital stay, or survival. Twenty-four of 25 survivors (96 %) could manage pancreatogenic diabetes by themselves, and the median level of glycosylated hemoglobin was 7.4 %. Although one-third of patients after TP complained of diarrhea and the QoL scores of patients with diarrhea were lower than those of patients without diarrhea, QoL scores after TP were virtually comparable with those of the national population, even in elderly patients.
TP can be performed safely, even in elderly patients. QoL after TP seems to be acceptable if patients are capable of self-management..
5. Ideno N, Ohtsuka T, Matsunaga T, Kimura H, Watanabe Y, Tamura K, Aso T, Aishima S, Miyasaka Y, Ohuchida K, Ueda J, Takahata S, Oda Y, Mizumoto K, Tanaka M, Clinical Significance of GNAS Mutation in Intraductal Papillary Mucinous Neoplasm of the Pancreas With Concomitant Pancreatic Ductal Adenocarcinoma, Pancreas, 44, 2, 311-320, 2015.04, OBJECTIVE:

The aims of this study were to investigate the GNAS mutational status in pancreatic intraductal papillary mucinous neoplasm (IPMN) with and without distinct pancreatic ductal adenocarcinoma (PDAC) and to evaluate the significance of GNAS analysis using duodenal fluid (DF) in patients with IPMN.


The clinicopathologic features of 110 patients with IPMN including 16 with distinct PDAC were reviewed. The GNAS status in the IPMN tissue and 23 DF specimens was assessed by sensitive mutation scanning methods.


The GNAS mutation rate in IPMN with distinct PDAC was significantly lower than that in IPMN without PDAC (4/16, 25%, vs 61/94, 65%; P = 0.0047). By multivariate analysis, GNAS wild-type and gastric type IPMNs were significantly associated with distinct PDAC. Of 45 GNAS wild-type IPMNs, 10 (43%) of 23 gastric type IPMNs had distinct PDAC, whereas only 2 (9%) of 22 non-gastric type IPMNs had distinct PDAC (P = 0.017). The GNAS status in DF was consistent with that in tissue in 21 (91%) of 23 patients.


Distinct PDACs frequently develop in the pancreas with gastric type IPMN without GNAS mutations. Duodenal fluid DNA test would predict the GNAS status of IPMN, whereas the detection of the gastric subtype using noninvasive test remains to be determined.This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.
6. Watanabe Y, Ohtsuka T, Kimura H, Matsunaga T, Tamura K, Ideno N, Aso T, Miyasaka Y, Ueda J, Takahata S, Tanaka M, Braun enteroenterostomy reduces delayed gastric emptying after pylorus-preserving pancreatoduodenectomy: a retrospective review, Am J Surg, 209, 2, 369-377, 2015.04, BACKGROUND: Several recent studies have suggested that Braun enteroenterostomy (BEE) during conventional pancreatoduodenectomy might decrease delayed gastric emptying (DGE). However, the advantages and disadvantages of performing BEE during pylorus-preserving pancreatoduodenectomy (PPPD) remain controversial.METHODS: The medical records of 185 patients who underwent PPPD either with or without BEE between January 2008 and June 2013 were retrospectively reviewed, and the postoperative course of the 2 groups was compared.RESULTS: Ninety-eight patients underwent PPPD with BEE and 87 without BEE. DGE occurred in 4% of patients with BEE and in 21% of those without BEE (P < .01). The addition of BEE did not affect postoperative complications other than DGE. By multivariate analysis, the omission of BEE was the only independent factor associated with DGE (odds ratio 5.04, 95% confidence interval: 1.59 to 19.66; P < .01).CONCLUSIONS: BEE during PPPD reduced the
incidence of DGE..
7. Tamura K, Ohtsuka T, Matsunaga T, Kimura H, Watanabe Y, Ideno N, Aso T, Miyazaki T, Ohuchida K, Takahata S, Ito T, Ushijima Y, Oda Y, Mizumoto K, Tanaka M, Assessment of Clonality of Multisegmental Main Duct Intraductal Papillary Mucinous Neoplasms of the Pancreas Based on GNAS Mutation Analysis, Surgery, 157, 2, 277-284, 2015.04, Background: Main duct intraductal papillary mucinous neoplasms (MD-IPMNs) may occur in one or multiple segments of the pancreatic duct. Unlike multifocal branch duct (BD)-IPMNs, the clonality of multisegmental MD-IPMNs remains unclear. GNAS mutations are common and specific for IPMNs, and mutational assessment might be useful to determine the clonality of IPMNs as well as to detect high-risk IPMN with distinct ductal adenocarcinoma (PDAC). Our aim was to clarify clonality using GNAS status in multisegmental MD-IPMNs.Methods: Medical records of 70 patients with MD-IPMN were retrospectively reviewed. Histological subtypes and KRAS/GNAS mutations were investigated, and the clonal relationships among multisegmental MD-IPMNs were assessed. Mutational analysis was performed using high-resolution melting analysis and subsequent Sanger/pyrosequencing.Results: Thirteen patients had multiple synchronous and/or metachronous lesions. Seven of these 13 patients had multip
le MD-IPMNs; three had multiple MD-IPMNs and distinct BD-IPMNs; one had multiple MD-IPMNs and a distinct PDAC; one had a solitary MD-IPMN, BD-IPMN, and PDAC; and one had a solitary MD-IPMN and PDAC. KRAS/GNAS mutations were consistent in 10 of 11 multisegmental MD-IPMNs, while MD-IPMNs, BD-IPMNs, and PDACs tended to show different mutational patterns. The frequency of malignant IPMNs was significantly higher in the multisegment cohort; malignant IPMNs constituted 90% (9/10) of the multiple cohort and 56% (32/57) of the solitary cohort (P=0.04). Mutant GNAS was more frequently observed in the intestinal subtype (94%) than the others.Conclusions: MD-IPMNs can be characterized by monoclonal skip progression. Close attention should be paid to the possible presence of skip areas during/after partial pancreatectomy..
8. Watanabe Y, Nishihara K, Niina Y, Abe Y, Amaike T, Kibe S, Mizuuchi Y, Kakihara D, Ono M, Tamiya S, Toyoshima S, Nakano T, Mitsuyama S, Validity of the management strategy for intraductal papillary mucinous neoplasm advocated by the International Consensus Guidelines 2012: a retrospective review, Surg Today, 46, 1045-1052, 2016.04, Abstract
The aim of this study was to investigate the validity of the management strategy for intraductal papillary mucinous neoplasms (IPMNs) advocated by the international consensus guidelines 2012 (ICG2012).
The medical records of 49 patients who underwent pancreatectomy for IPMN were retrospectively reviewed.
According to preoperative imaging, 10 patients (20 %) had main-duct IPMNs, 20 (41 %) had mixed IPMNs, and 19 (39 %) had branch-duct IPMNs, with malignancy frequencies of 80, 15, and 37 %, respectively. Twenty-seven patients had high-risk stigmata and 21 had worrisome features, with malignancy frequencies of 59 and 10 %, respectively. The sensitivity, specificity, and positive and negative predictive values of high-risk stigmata for malignancy were 88, 65, 59, and 91 %, respectively. Lesions were malignant in 88 % of patients with an enhanced solid component, which was significantly correlated with the prevalence of malignancy (P CONCLUSIONS:
Many mixed IPMNs defined according to ICG2012 are benign. Although the management strategy advocated by ICG2012 has been improved relative to the Sendai criteria, the different high-risk stigmata carry unequal weights. Consequently, ICG2012 remains suboptimal for predicting malignant IPMN.
High-risk stigmata; International consensus guidelines; Intraductal papillary mucinous neoplasms; Worrisome feature.
9. Tamura K, Ohtsuka T, Date K, Fujimoto T, Matsunaga T, Kimura H, Watanabe Y, Miyazaki T, Ohuchida K, Takahata S, Ishigami K, Oda Y, Mizumoto K, Nakamura M, Tanaka M, Distinction of Invasive Carcinoma Derived From Intraductal Papillary Mucinous Neoplasms From Concomitant Ductal Adenocarcinoma of the Pancreas Using Molecular Biomarkers, Pancreas, 10.1097/MPA.0000000000000563 , 45, 6, 826-835, 2016.04, OBJECTIVES:To clarify the usefulness of molecular biomarkers for distinguishing invasive carcinoma derived from intraductal papillary mucinous neoplasms (IPMNs [Inv-IPMN]) from concomitant pancreatic ductal adenocarcinoma (PDAC).METHODS:Data from 19 patients with resected concomitant PDAC were retrospectively reviewed. KRAS/GNAS mutations and immunohistochemical (IHC) expression of p53 and p16/CDKN2A were assessed in both IPMN and distinct PDAC. As controls, KRAS/GNAS mutations and IHC labeling were assessed between invasive and noninvasive components in 1 lesion of 22 independent patients.RESULTS:KRAS/GNAS mutation status of invasive and noninvasive components in Inv-IPMN was consistent in 18 (86%) of 21 patients. Conversely, mutational patterns in IPMN and distinct PDAC in the same pancreas differed from each other in 17 (89%) of 19. There were 10 (53%) and 8 (42%) of 19 patients who showed the same p53 and p16/CDKN2A staining between concomitant PDAC and d
istinct IPMN. In the Inv-IPMN cohort, 19 (86%) of 22 patients showed the same IHC expression pattern between the noninvasive and invasive components.CONCLUSIONS:It may be possible to distinguish Inv-IPMN from concomitant PDAC by assessing these molecular biomarkers. More precise distinction of Inv-IPMN and concomitant PDAC will lead to adequate recognition of the natural history of IPMNs and hence optimal management..
10. Watanabe Y, Nishihara K, Niina Y, Kudo Y, Kurata K, Okayama T, Fujii A, Wakamatsu S, Abe Y, Nakano T, Patients with lung recurrence after curative resection for pancreatic ductal adenocarcinoma have a better prognosis than those with recurrence at other sites, JOP, 18, 1, 56-61, 2017.04.
11. Watanabe Y, Nishihara K, Matsumoto S, Okayama T, Abe Y, Nakano T, Effect of postoperative major complications on prognosis after pancreatectomy for pancreatic cancer: a retrospective review, Surg Today, 47, 5, 555-567, 2017.04, Abstract
To investigate the impact of postoperative complications on survival after curative resection for pancreatic cancer.
We reviewed retrospectively the medical records of 122 patients who underwent curative R0 resection for pancreatic cancer. Major complications included pancreatic fistula and hemorrhage of grade B or C according to the International Study Group of Pancreatic Fistula or Surgery criteria, and other complications of grade ≥III according to the Clavien-Dindo classification.
Thirty-eight patients (31 %) suffered major postoperative complications and 40 patients (33 %) suffered minor complications only. Univariate survival analysis showed that patients with major complications had a significantly worse prognosis than those without major complications, with regard to recurrence-free survival (RFS) (P CONCLUSIONS:
Postoperative major complications after pancreatectomy for pancreatic cancer affect the prognosis..
12. Watanabe Y, Anan K, Saimura M, Koga K, Fujino M, Mine M, Tamiya S, Nishihara K, Nakano T, Mitsuyama S, Upstaging to invasive ductal carcinoma after mastectomy for ductal carcinoma in situ: predictive factors and role of sentinel lymph node biopsy, Breast Cancer, 25, 6, 663-670, 2018.04.
13. Kameda C, Watanabe M, Suehara N, Watanabe Y, Nishihara K, Nakano T, Nakamura M, Safety of laparoscopic distal gastrectomy for gastric cancer when performed by trainee surgeons with little experience in performing open gastrectomy, Surg Today, 10.1007/s00595-017-1569-8, 48, 2, 211-216, 2018.04, Purpose: This study aimed to evaluate the surgical outcomes and clinical safety of laparoscopic distal gastrectomy (LDG) when performed by trainee surgeons with little prior experience in performing open gastrectomy, under the guidance of trainer surgeons.Methods: From January 2008 until March 2015, 17 trainee surgeons and 5 trainer surgeons performed LDGs to treat 371 patients with clinical stage T1-T3 gastric cancer. Of these patients, 140 and 231 underwent LDG performed by trainee surgeons and trainer surgeons, respectively. We retrospectively analyzed the surgical outcomes of the two groups.Results: Trainee surgeons required significantly longer operation times than the trainer surgeons, with respective mean operation times of 262 and 223 minutes (p < 0.001). However, the mean blood loss volumes, average numbers of retrieved lymph nodes, postoperative complications, and postoperative hospital stay lengths did not differ significantly between LD
Gs performed by trainee surgeons and trainer surgeons. Conclusions: The study findings suggest that, under the guidance of trainer surgeons, trainee surgeons with little experience with open gastrectomy and even without prior experience with LDG can perform radical surgeries safely..
14. Watanabe Y, Niina Y, Nishihara K, Okayama T, Tamiya S, Nakano T, Neutrophil-to-lymphocyte ratio and mural nodule height as predictive factors for malignant intraductal papillary mucinous neoplasms, Acta Chir Belg, 10.1080/00015458.2018., 118, 4, 239-245, 2018.04.
15. Watanabe Y, Shinkawa T, Endo S, Abe Y, Nishihara K, Nakano T, Long-Term Outcomes After Pancreatectomy for Pancreatic Ductal Adenocarcinoma in Elderly Patients: Special Reference to Postoperative Adjuvant Chemotherapy, World J Surg, 10.1007/s00268-018-4496-y., 42, 8, 2617-2626, 2018.04, Abstract
The benefit of pancreatectomy for elderly patients with pancreatic ductal adenocarcinoma (PDAC) remains controversial. Moreover, adjuvant chemotherapy (AC) for elderly patients has not been fully evaluated. We investigated the long-term outcomes after pancreatectomy for PDAC in elderly patients with special reference to AC.

The medical records of 123 patients who underwent pancreatectomy for PDAC from 2007 to 2016 were retrospectively reviewed. The patients were divided into two groups: young (
The study population comprised 91 young and 32 elderly patients. The postoperative clinical courses were not different between the two groups. AC was more frequently administered to young (85%) than elderly patients (66%; P = 0.04). The weekly dose of tegafur/gimeracil/oteracil potassium (S1) for AC was significantly lower in elderly (median 423 mg/m2) than young patients (median 491 mg/m2; P = 0.02). The prevalence of adverse events and the completion rate of AC were not significantly different between the two groups. There were no significant differences in recurrence-free survival (P = 0.73) or overall survival (P = 0.68) between the two groups in univariate analysis. Receipt of AC was not a significant independent factor for survival, and completion of planned AC was a significant independent factor for recurrence-free survival and overall survival in multivariate analysis.

The benefit of pancreatectomy for PDAC was the same between young and elderly patients. Completion of planned AC was important, and lowered-dose AC using S1 for elderly patients might be safe and therapeutically useful..
16. Kurahara H, Shinchi H, Ohtsuka T, Miyasaka Y, Matsunaga T, Noshiro H, Adachi T, Eguchi S, Imamura N, Nanashima A, Sakamoto K, Nagano H, Ohta M, Inomata M, Chikamoto A, Baba H, Watanabe Y, Nishihara K, Yasunaga M, Okuda K, Natsugoe S, Nakamura M, Significance of neoadjuvant therapy for borderline resectable pancreatic cancer: a multicenter retrospective study, Langenbecks Arch Surg, 10.1007/s00423-019-01754-5, 404, 2, 167-174, 2019.04, Abstract
Neoadjuvant therapy (NAT) is increasingly used to improve the prognosis of patients with borderline resectable pancreatic cancer (BRPC) albeit with little evidence of its advantage over upfront surgical resection. We analyzed the prognostic impact of NAT on patients with BRPC in a multicenter retrospective study.
Medical data of 165 consecutive patients who underwent treatment for BRPC between January 2010 and December 2014 were collected from ten institutions. We defined BRPC according to the National Comprehensive Cancer Network guidelines, and subclassified patients according to venous invasion alone (BR-PV) and arterial invasion (BR-A).
The rates of NAT administration and resection were 35% and 79%, respectively. There were no significant differences in resection rates and prognoses between patients in the BR-PV and BR-A subgroups. NAT did not have a significant impact on prognosis according to intention-to-treat analysis. However, in patients who underwent surgical resection, NAT was independently associated with longer overall survival (OS). The median OS of patients who underwent resection after NAT (53.7 months) was significantly longer than that of patients who underwent upfront (17.8 months) or no resection (14.9 months). The rates of superior mesenteric or portal vein invasion, lymphatic invasion, venous invasion, and lymph node metastasis were significantly lower in patients who underwent resection after NAT than in those who underwent upfront resection despite similar baseline clinical profiles.
17. Yusuke Mizuuchi, Yoshitaka Tanabe, Masafumi Sada, Yoshiki Kitaura, Shuntaro Nagai, Yusuke Watanabe, Sadafumi Tamiya, Kinuko Nagayoshi, Kenoki Ohuchida, Toru Nakano, Masafumi Nakamura, Predictive factors associated with relapse of stage II/III colon cancer treated with peroral anti-cancer agents in the adjuvant setting, Mol Clin Oncol, 10.3892/mco.2021.2284., 14, 6, 122, 2021.04.
18. Kohei Nakata, Yasuhisa Mori, Naoki Ikenaga, Noboru Ideno, Yusuke Watanabe, Yoshihiro Miyasaka, Takao Ohtsuka, Masafumi Nakamura, Management of postoperative pancreatic fistula after pancreatoduodenectomy: Analysis of 600 cases of pancreatoduodenectomy patients over a 10-year period at a single institution, Surgery., 10.1016/j.surg.2021.01.010, 169, 6, 1446-1453, 2021.04, Abstract
Background: Although postoperative pancreatic fistula (POPF) is a common and critical complication of pancreatoduodenectomy (PD), effective strategies to prevent POPF have not yet been completely developed. Because appropriate management of POPF is important to reduce the mortality rate after PD, in this study we aimed to evaluate our approach for the management of POPF after PD, including the postoperative course.

Methods: This retrospective study included 605 consecutive patients who underwent PD at our hospital between 2010 and 2020. All patients who developed POPF were first managed conservatively, with drainage tubes placed during surgery retained to manage POPF. In cases wherein conservative treatment was unsuccessful, open drainage, followed by continuous negative pressure and continuous irrigation, was used. For open drainage, the surgical wound was opened bluntly (approximate length, 5 cm) under local anesthesia, and the fluid was directly and completely drained.

Results: The prevalence of POPF of grades B and C was 15.4% (n = 93) and 0.33% (n = 2), respectively. Of these patients, 1 required reoperation, 43 recovered with conservative management only, 47 required open drainage, and 4 required image-guided percutaneous drainage. Postoperative hemorrhage with a pseudoaneurysm was identified in 3 (0.66%) patients. The postoperative in-hospital mortality rate was low (n = 1, 0.16%). The rate of successful POPF management was 98.9%.

Conclusion: Based on our high success rate in POPF management, we consider open drainage to be a safe primary management method for POPF..
19. Ryuichiro Kimura, Takao Ohtsuka, Makoto Kubo, Atsuko Kajihara, Atsushi Fujii, Yusuke Watanabe, Yasuhisa Mori, Naoki Ikenaga, Kohei Nakata, Koji Shindo, Kenoki Ohuchida, Masafumi Nakamura, FoundationOne® CDx gene profiling in Japanese pancreatic ductal adenocarcinoma patients: a single-institution experience , Surgery Today, 10.1007/s00595-020-02123-2 , 51, 4, 619-626, 2021.04, Abstract
Purpose: The aim of this study was to investigate the genetic mutation profiles of Japanese pancreatic ductal adenocarcinoma (PDAC) patients.
Methods: Next-generation sequencing was performed using FoundationOne® CDx on 17 PDAC patients who were treated by surgical resection at Kyushu University Hospital between February 2016 and January 2019. The tumor mutational burden and microsatellite instability status were also assessed.
Results: There were 16 patients (94%) with KRAS mutations, 13 (76%) with TP53 mutations, three (18%) with SMAD4 mutations, and one (6%) with a CDKN2A mutation. All patients had at least one pathogenic variant or a likely pathogenic variant. No patient had targeted therapies that matched with any clinical benefit according to FoundationOne® CDx. An unresectable PDAC patient with BRCA2-mutant disease was successfully treated by conversion surgery using platinum-based neoadjuvant chemotherapy.
Conclusions: Currently, FoundationOne® CDx might be difficult to use on PDAC patients, although further investigations with larger study populations are called for.
Keywords: FoundationOne; Gene profiling; Next-generation sequencing; Pancreatic cancer; Pancreatic ductal adenocarcinoma.
20. Kohei Nakata, Takao Ohtsuka, Yoshihiro Miyasaka, Yusuke Watanabe, Noboru Ideno, Yasuhisa Mori, Naoki Ikenaga, Masafumi Nakamura, Evaluation of relationship between splenic artery and pancreatic parenchyma using three-dimensional computed tomography for laparoscopic distal pancreatectomy, Langenbecks Arch Surg, 10.1007/s00423-021-02101-3, 406, 6, 1885-1895, 2021.04, Abstract
Aim: Isolating the root of the splenic artery (SPA) is a challenging procedure in laparoscopic distal pancreatectomy (LDP). We investigated the usefulness of evaluation of the relationship between the SPA and pancreatic parenchyma using three-dimensional computed tomography (3D-CT).

Methods: In total, 104 patients were evaluated. The relationship between the SPA and pancreatic parenchyma was classified into two types: buried and non-buried. Video clips of 50 patients who underwent LDP requiring isolation of the SPA root were reviewed to determine whether the classification is related to difficulty of LDP.

Results: Of the 50 assessed patients who underwent LDP, the relationship between the SPA and pancreatic parenchyma was the buried type in 30 (60.0%) and non-buried type in 20 (40.0%). The buried type was associated with a significantly longer median operative time than the non-buried type (285.0 vs. 235.5 min, respectively; P
Conclusion: Preoperative 3D-CT around the pancreas is practical for predicting the difficulty of SPA isolation and determining the safety of the procedure..
21. Naoki Ikenaga, Takao Ohtsuka, Kohei Nakata, Yusuke Watanabe, Yasuhisa Mori, Masafumi Nakamura, Clinical significance of postoperative acute pancreatitis after pancreatoduodenectomy and distal pancreatectomy, Surgery, 10.1016/j.surg.2020.06.040, 169, 4, 732-737, 2021.04, Abstract
Background: The definition of postoperative acute pancreatitis as a specific complication of pancreatic surgery was proposed in 2016. Its presence and relevance have not been established, especially after a distal pancreatectomy.

Methods: Medical records of 319 patients who underwent pancreatoduodenectomy or distal pancreatectomy were analyzed. Postoperative acute pancreatitis was defined as an increase in serum amylase activity greater than the upper normal limit on postoperative day 1, according to Connor's definition of postoperative acute pancreatitis.

Results: Postoperative acute pancreatitis occurred in 63.4% of 153 of the patients undergoing pancreatoduodenectomy and 65.7% of the 166 undergoing distal pancreatectomies. Patients who developed postoperative acute pancreatitis after pancreatoduodenectomy experienced an increase in the rate of morbidity (22.7% vs 7.1%; P = .0137), including postoperative pancreatic fistula (18.6% vs 1.8%; P = .024), resulting in greater postoperative stays (21 days vs 17 days; P = .0008). Postoperative acute pancreatitis in association with an increased serum C-reactive protein ≥18.0 mg/dL (which we defined as a clinically relevant postoperative acute pancreatitis) more strongly indicated the occurrence of severe complications (P = .0032) and was an independent predictor of postoperative pancreatic fistula after pancreatoduodenectomy (odds ratio, 3.03; P = .0448). Patients who developed postoperative acute pancreatitis after distal pancreatectomy experienced similar postoperative courses regarding morbidity and the duration of postoperative stay.

Conclusion: The clinical relevance of postoperative acute pancreatitis differs after a pancreatoduodenectomy versus a distal pancreatectomy. The development of effective strategies for preventing postoperative acute pancreatitis might improve surgical outcomes after pancreatoduodenectomy..
22. Shinichiro Ono, Tomohiko Adachi, Takao Ohtsuka, Ryuichiro Kimura, Kazuyoshi Nishihara, Yusuke Watanabe, Hiroaki Nagano, Yukio Tokumitsu, Atsushi Nanashima, Naoya Imamura, Hideo Baba, Akira Chikamoto, Masafumi Inomata, Teijiro Hirashita, Masayuki Furukawa, Tetsuya Idichi, Hiroyuki Shinchi, Yuichiro Maruyama, Masafumi Nakamura, Susumu Eguchi, Predictive factors for early recurrence after pancreaticoduodenectomy in patients with resectable pancreatic head cancer: A multicenter retrospective study, surgery, 10.1016/j.surg.2022.08.004, 172, 6, 1782-1790, 2022.04, Background: Patients diagnosed with resectable pancreatic ductal adenocarcinoma often experience early recurrence even after upfront R0 resection. This study aimed to define early recurrence and identify preoperative risk factors for early recurrence after upfront pancreaticoduodenectomy in patients with resectable pancreatic ductal adenocarcinoma of the pancreatic head.
Methods: This multicenter, retrospective study involved 500 patients who underwent pancreaticoduodenectomy resectable pancreatic ductal adenocarcinoma of the pancreatic head at 10 institutions between 2007 and 2016. Preoperative, intraoperative, and postoperative clinicopathological results were compared between early and non-early recurrence groups. Predictors of early recurrence were determined using statistical analyses.
Results: Log-rank tests revealed a significant difference (P Conclusion: The optimal period that defines the early recurrence for resectable pancreatic ductal adenocarcinoma of the pancreatic head is 6 months. Tumor size ≥20 mm, preoperative carbohydrate antigen 19-9 levels ≥120 U/mL, retroperitoneal invasion of the tumor, and the presence of diabetes mellitus are independently associated with early recurrence..
23. Yuichi Nagakawa, Kohei Nakata, Hitoe Nishino, Takao Ohtsuka, Daisuke Ban, Horacio J Asbun, Ugo Boggi, Jin He, Michael L Kendrick, Chinnusamy Palanivelu, Rong Liu, Shin-E Wang, Chung-Ngai Tang, Kyoichi Takaori, Mohammed Abu Hilal, Brian K P Goh, Goro Honda, Jin-Young Jang, Chang Moo Kang, David A Kooby, Yoshiharu Nakamura, Shailesh V Shrikhande, Christopher L Wolfgang, Anusak Yiengpruksawan, Yoo-Seok Yoon, Yusuke Watanabe, Shingo Kozono, Ruben Ciria, Giammauro Berardi, Giovanni Maria Garbarino, Ryota Higuchi, Naoki Ikenaga, Yoshiya Ishikawa, Aya Maekawa, Yoshiki Murase, Giuseppe Zimmitti, Filipe Kunzler, Zi-Zheng Wang, Leon Sakuma, Chie Takishita, Hiroaki Osakabe, Itaru Endo, Masao Tanaka, Hiroki Yamaue, Minoru Tanabe, Go Wakabayashi, Akihiko Tsuchida, Masafumi Nakamura, International expert consensus on precision anatomy for minimally invasive pancreatoduodenectomy: PAM-HBP surgery project, J Hepatobiliary Pancreat Sci, 10.1002/jhbp.1081, 29, 1, 124-135, 2022.04, Abstract
Background: The anatomical structure around the pancreatic head is very complex and it is important to understand its precise anatomy and corresponding anatomical approach to safely perform minimally invasive pancreatoduodenectomy (MIPD). This consensus statement aimed to develop recommendations for elucidating the anatomy and surgical approaches to MIPD.
Methods: Studies identified via a comprehensive literature search were classified using the Scottish Intercollegiate Guidelines Network method. Delphi voting was conducted after experts had drafted recommendations, with a goal of obtaining >75% consensus. Experts discussed the revised recommendations with the validation committee and an international audience of 384 attendees. Finalized recommendations were made after a second round of online Delphi voting.
Results: Three clinical questions were addressed, providing six recommendations. All recommendations reached at least a consensus of 75%. Preoperatively evaluating the presence of anatomical variations and superior mesenteric artery (SMA) and superior mesenteric vein (SMV) branching patterns was recommended. Moreover, it was recommended to fully understand the anatomical approach to SMA and intraoperatively confirm the SMA course based on each anatomical landmark before initiating dissection.
Conclusions: MIPD experts suggest that surgical trainees perform resection based on precise anatomical landmarks for safe and reliable MIPD.
Keywords: consensus; minimally invasive surgical procedures; pancreatoduodenectomy; robotic surgery; superior mesenteric artery..
24. Daisuke Ban, Hitoe Nishino, Takao Ohtsuka, Yuichi Nagakawa, Mohammed Abu Hilal, Horacio J Asbun, Ugo Boggi, Brian K P Goh, Jin He, Goro Honda, Jin-Young Jan, Chang Moo Kang, Michael L Kendrick, David A Kooby, Rong Liu, Yoshiharu Nakamura, Kohei Nakata, Chinnusamy Palanivelu, Shailesh V Shrikhande, Kyoichi Takaori, Chung-Ngai Tang, Shin-E Wan, Christopher L Wolfgang, Anusak Yiengpruksawan, Yoo-Seok Yoon, Ruben Ciria, Giammauro Berardi, Giovanni Maria Garbarino, Ryota Higuchi, Naoki Ikenaga, Yoshiya Ishikawa, Shingo Kozono, Aya Maekawa, Yoshiki Murase, Yusuke Watanabe, Giuseppe Zimmitti, Filipe Kunzler, Zi-Zheng Wang, Leon Sakuma, Hiroaki Osakabe, Chie Takishita, Itaru Endo, Masao Tanaka, Hiroki Yamaue, Minoru Tanabe, Go Wakabayashi, Akihiko Tsuchida, Masafumi Nakamura, International Expert Consensus on Precision Anatomy for minimally invasive distal pancreatectomy: PAM-HBP Surgery Project, J Hepatobiliary Pancreat Sci, 10.1002/jhbp.1071, 29, 1, 161-173, 2022.04, Background: Surgical views with high resolution and magnification have enabled us to recognize the precise anatomical structures that can be used as landmarks during minimally invasive distal pancreatectomy (MIDP). This study aimed to validate the usefulness of anatomy-based approaches for MIDP before and during the Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (February 24, 2021).
Methods: Twenty-five international MIDP experts developed clinical questions regarding surgical anatomy and approaches for MIDP. Studies identified via a comprehensive literature search were classified using Scottish Intercollegiate Guidelines Network methodology. Online Delphi voting was conducted after experts had drafted the recommendations, with the goal of obtaining >75% consensus. Experts discussed the revised recommendations in front of the validation committee and an international audience of 384 attendees. Finalized recommendations were made after a second round of online Delphi voting.
Results: Four clinical questions were addressed, resulting in 10 recommendations. All recommendations reached at least a 75% consensus among experts..
25. Yusuke Watanabe, Kohei Nakata, Yasuhisa Mori, Noboru Ideno, Naoki Ikenaga, Takao Ohtsuka, Masafumi Nakamura, Extensive (subtotal) distal pancreatectomy for pancreatic ductal adenocarcinoma: a propensity score matched cohort study of short- and long-term outcomes compared with those of conventional distal pancreatectomy, Langenbecks Arch Surg, 10.1007/s00423-022-02453-4, 407, 4, 1479-1488, 2022.04, Abstract
Purpose: Extensive distal pancreatectomy (ExDP) can transect the pancreatic parenchyma more from the right side than conventional distal pancreatectomy (CDP) can. This study aimed to evaluate the short- and long-term outcomes of ExDP for pancreatic ductal adenocarcinoma (PDAC) of the pancreatic body, located adjacent to the portal vein (PV).
Methods: Medical records of 98 patients who underwent ExDP (n = 15) or CDP (n = 83) for PDAC were retrospectively reviewed. Short- and long-term outcomes of the two groups were compared. Propensity score matched analysis was additionally performed to minimize the impact of treatment allocation bias.
Results: In the total cohort, the CDP group had a significantly higher proportion of pancreatic tail lesions (P Conclusions: Surgical and oncological outcomes after ExDP for PDAC were acceptable and comparable to those after CDP. ExDP is a feasible procedure, and could be an option for the treatment of PDAC of the pancreatic body near PV.
Keywords: Distal pancreatectomy; Extensive distal pancreatectomy; Pancreatic cancer; Pancreatic ductal adenocarcinoma; Subtotal distal pancreatectomy..
26. Yusuke Mizuuchi, Yoshitaka Tanabe, Masafumi Sada, Koji Tamura, Kinuko Nagayoshi, Shuntaro Nagai, Yusuke Watanabe, Sadafumi Tamiya, Kohei Nakata, Kenoki Ohuchida, Toru Nakano, Masafumi Nakamura, Cross-sectional area of psoas muscle as a predictive marker of anastomotic failure in male rectal cancer patients: Japanese single institutional retrospective observational study, Annals of Coloproctology, 10.3393/ac.2022.00122.0017, 38, 5, 353-361, 2022.04, Purpose: Preoperative sarcopenia worsens postoperative outcomes in various cancer types including colorectal cancer. However, we often experienced postoperative anastomotic leakage in muscular male patients such as Judo players, especially in rectal cancer surgery with lower anastomosis. It is controversial whether the whole skeletal muscle mass impacts the potential for anastomotic failure in male rectal cancer patients. Thus, the purpose of this study was to clarify whether skeletal muscle mass impacts anastomotic leakage in rectal cancer in men.

Methods: We reviewed the medical charts of male patients suffering from rectal cancer who underwent colo-procto anastomosis below the peritoneal reflection without a protective diverting stoma. We measured the psoas muscle area and calculated the psoas muscle index.

Results: One hundred ninety-seven male rectal cancer patients were enrolled in this study. The psoas muscle index was significantly higher in patients with anastomotic leakage (P<0.001). Receiver operating characteristic curve determined the optimal cut-off value of the psoas muscle index for predicting anastomotic leakage as 812.67 cm2/m2 (sensitivity of 60% and specificity of 74.3%). Multivariate analysis revealed that high psoas muscle index (risk ratio [RR], 3.933; P<0.001; 95% confidence interval [CI], 1.917-8.070) and super low anastomosis (RR, 2.792; P=0.015; 95% CI, 1.221-6.384) were independent predictive factors of anastomotic leakage.

Conclusion: This study showed that male rectal cancer patients with a large psoas muscle mass who underwent lower anastomosis had a higher rate of postoperative anastomotic leakage.

Keywords: Anastomotic leak; Lower colo-anorectal anastomosis; Psoas muscle index; ROC curve; Rectal neoplasms..
27. Koji Asai, Yukio Iwashita, Tetsuji Ohyama, Itaru Endo, Taizo Hibi, Akiko Umezawa, Kenji Suzuki, Manabu Watanabe, Masanao Kurata, Yasuhisa Mori, Masaharu Higashida, Yusuke Kumamoto, Junichi Shindoh, Masahiro Yoshida, Goro Honda, Takeyuki Misawa, Yuta Abe, Yuichi Nagakawa, Naoyuki Toyota, Shigetoshi Yamada, Shinji Norimizu, Naoki Matsumura, Naohiro Sata, Hiroki Sunagawa, Masahiro Ito, Yutaka Takeda, Yoshiharu Nakamura, Toshiki Rikiyama, Ryota Higuchi, Takeshi Gocho, Yuki Homma, Teijiro Hirashita, Hideyuki Kanemoto , Masashi Nozawa, Yusuke Watanabe, Atsushi Kohga, Takehisa Yazawa, Hiroshi Tajima, Shin Nakahira, Tadafumi Asaoka, Ryuji Yoshioka, Junya Fukuzawa, Shuichi Fujioka, Taigo Hata, Hidenori Haruta, Yukio Asano, Ryohei Nomura, Joe Matsumoto, Noriaki Kameyama, Atsushi Miyoshi, Hidejiro Urakami, Yasuji Seyama, Takanori Morikawa, Yoichi Kawano, Hisashi Ikoma, Dal Ho Kim Kin, Tadahiro Takada, Masakazu Yamamoto, Application of a novel surgical difficulty grading system during laparoscopic cholecystectomy, J Hepatobiliary Pancreat Sci, 10.1002/jhbp.1068, 29, 7, 758-767, 2022.04, Background: Prevention of bile duct injury and vasculo-biliary injury while performing laparoscopic cholecystectomy (LC) is an unsolved problem. Clarifying the surgical difficulty using intraoperative findings can greatly contribute to the pursuit of best practices for acute cholecystitis. In this study, multiple evaluators assessed surgical difficulty items in unedited videos and then constructed a proposed surgical difficulty grading.
Methods: We previously assembled a library of typical video clips of the intraoperative findings for all LC surgical difficulty items in acute cholecystitis. Fifty-one experts on LC assessed unedited surgical videos. Inter-rater agreement was assessed by Fleiss's κ and Gwet's agreement coefficient (AC).
Results: Except for one item ("edematous change"), κ or AC exceeded 0.5, so the typical videos were judged to be applicable. The conceivable surgical difficulty gradings were analyzed. According to the assessment of difficulty factors, we created a surgical difficulty grading system (agreement probability = 0.923, κ = 0.712, 90% CI: 0.587-0.837; AC2 = 0.870, 90% CI: 0.768-0.972).
Conclusion: The previously published video clip library and our novel surgical difficulty grading system should serve as a universal objective tool to assess surgical difficulty in LC.
Keywords: acute cholecystitis; bile duct injury; laparoscopic cholecystectomy; surgical difficulty; vasculobiliary injury..
28. Yusuke Mizuuchi, Yoshitaka Tanabe, Masafumi Sada, Koji Tamura, Kinuko Nagayoshi, Shuntaro Nagai, Yusuke Watanabe, Sadafumi Tamiya, Kenoki Ohuchida, Kohei Nakata, Toru Nakano, Masafumi Nakamura, Relationship between prognostic impact of N3 lymph node metastasis at the root of the feeding artery and location of colon cancer, Langenbecks Arch Surg, 10.1007/s00423-023-02778-8, 408, 1, 31, 2023.04, Purpose: To determine whether N3 nodal involvement predicts outcomes and whether its prognostic implications vary with tumor location in patients with Stage III colon cancer (CC).

Methods: We defined N3 as lymph node metastases near the bases of the major feeding arteries. We retrospectively examined recurrence rates and patterns by tumor location and sites of lymph node metastases in 57 patients with N3 CC who had undergone curative resections between January 2000 and March 2019. Survival analysis was performed to compare the prognoses of patients with and without N3 lymph node metastasis.

Results: Most N3 patients had large tumors (T ? 3); five had T2 disease. Recurrence occurred quickly in one patient with T2N3M0 disease. Multivariate survival analysis demonstrated that N3 lymph node metastasis is an independent predictor of poor prognosis in Stage III CC patients (P < 0.001). Categorizing N3 patients according to UICC-TNM staging system does not stratify risk of recurrence (P = 0.970). To investigate the impact of tumor location on recurrence risk, we classified N3 CC into two subtypes according to tumor location: metastasis at the base of the superior mesenteric artery in right-sided CC and inferior mesenteric artery in left-sided CC. The former was found to have a statistically significant poorer prognosis than the latter (P = 0.091).

Conclusion: N3 is a robust prognostic marker in CC patients. Recurrence risk varies by tumor location. N3 right-sided CCs with lymph node metastasis at the base of the superior mesenteric artery have poorer prognoses than do N3 left-sided CCs.

Keywords: Feeding artery; Inferior mesenteric artery; N3 colon cancer; Superior mesenteric artery; Tumor sidedness..
29. Koji Tamura, Takashi Ueki, Hiromichi Nakayama, Yusuke Watanabe, Masafumi Sada, Kinuko Nagayoshi, Yusuke Mizuuchi, Kenoki Ohuchida, Hitoshi Ichimiya, Masafumi Nakamura, Preoperative prediction of malignancy and surgical treatment strategy in appendiceal tumors: multicenter review of 51 consecutive cases, Langenbecks Arch Surg , 10.1007/s00423-023-02807-6, 408, 1, 36, 2023.04, urpose: A diagnostic and treatment strategy for appendiceal tumors (ATs) has not been established. We aimed to evaluate our treatment strategy in ATs, including laparoscopic surgery (LS), and to identify preoperative malignancy predictors.
Methods: A total of 51 patients between 2011 and 2021 were retrospectively reviewed. Data, including tumor markers and imaging findings, were compared between carcinoma and non-carcinoma patients. Validity of planned operation was evaluated based on pathological diagnosis.
Results: Twenty-five patients were diagnosed with carcinoma, 13 with low-grade mucinous neoplasm, and 13 with other diseases. Symptoms were more commonly present in carcinoma patients than in non-carcinoma patients (68.0% vs. 23.1%, p = 0.001). Elevated CEA and CA19-9 were more frequently observed in carcinoma patients than in non-carcinoma patients (p Conclusion: Clinical symptoms, elevated tumor markers, and worrisome features of solid enhanced mass and tumor wall irregularity on imaging can be malignancy predictors. For management of ATs, LS is feasible and useful for diagnosis and treatment.
Keywords: Appendiceal carcinoma; Appendiceal tumor; LAMN; Laparoscopic surgery; Mucinous neoplasm..