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Affiliation |
Faculty of Medicine College Hospital The first surgery |
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Associate Professor |
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Related SDGs |
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IMAMURA Naoya
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Papers 【 display / non-display 】
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Imamura N., Nanashima A., Tsuchimochi Y., Hamada T., Kawakami H., Hiyoshi M.
Gland Surgery 14 ( 4 ) 714 - 725 2025.4
Authorship：Lead author, Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Gland Surgery
Background: Neoadjuvant chemotherapy (NAC) has been increasingly used in recent years in patients with pancreatic ductal adenocarcinoma (PDAC). This has forced a change in the practice of preoperative biliary drainage (PBD) is performed in PDAC patients scheduled for pancreatoduodenectomy (PD). What has changed in the NAC era and what is the appropriate method of PBD? To address this question, this study retrospectively reviewed the surgical outcomes and details of PBD in NAC and upfront surgery (US) patients. Methods: The study included consecutive PDAC patients who underwent PD from 2013 to 2021 during the transition from US to NAC, when outcomes were comparable. Clinical factors such as patient background, preoperative examination, surgical procedure, and postoperative complications were compared between the NAC group (40 patients) and the US group (59 patients), and details of PBD such as PBD procedure and adverse events were compared between the NAC and US groups who received PBD (27 NAC patients, 33 US patients). In the comparison test between groups, Fisher’s exact test and Mann-Whitney U test were mainly used. In addition, the outcomes and patency periods of each of the 128 PBD procedures were examined for the 60 patients who underwent PBD. The log-rank test was performed using the Kaplan-Meier method to compare patency period by PBD procedure. Results: There were no differences in patient background between the NAC and US groups. Compared with the US group, the NAC group had higher preoperative albumin (ALB) levels and less blood loss, but there was no difference of postoperative complications (NAC vs. US, 35% vs. 46%, respectively, P=0.29). With respect to PBD, the NAC group had more initial metallic stent (MS) placement (NAC vs. US, 52% vs. 15%, respectively, P=0.009), and fewer PBD-related adverse events (NAC vs. US, 33% vs. 61%, respectively, P=0.04). In a comparison of outcomes by drainage method, the duration of patency was significantly longer with MS placement than plastic stent (PS) placement (median days of patency, MS vs. PS, 68 vs. 15 days, respectively, P<0.001). However, MS placement and PS placement were equally likely to require a delay in the surgical schedule due to PBD-related adverse events (MS vs. PS, 6% vs. 6%, respectively, P>0.99). Conclusions: Prolonged PBD with NAC did not adversely affect surgical outcomes. MS placement provides a long patency period and is currently useful in PBD for PDAC patients undergoing PD after NAC, which requires a prolonged preoperative period. However, MS placement also has adverse events, and further studies are needed.
DOI： 10.21037/gs-2024-507
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Nanashima A., Imamura N., Hiyoshi M., Tsuchimochi Y., Wada T., Hamada T., Suzuki Y., Araki Y., Hosokawa A., Kawakami H.
Cancer Diagnosis and Prognosis 6 ( 2 ) 291 - 302 2026.3
Language：English Publishing type：Research paper (scientific journal) Publisher：Cancer Diagnosis and Prognosis
Background/Aim: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a precursor lesion with variable malignant potential. Due to its heterogeneity, optimal treatment strategies remain controversial, especially regarding surgical resection and surveillance indications. We reviewed our institutional outcomes to reassess the current postoperative strategy and refine management guidelines. Patients and Methods: This study retrospectively and consecutively analyzed the data of 49 IPMN patients who underwent pancreatectomy at an academic institution from 2015 to May 2025. Results: Diagnostic mismatch between preoperative and final pathological findings was observed in 39% of cases, with overdiagnosis (downgrade group) beingmore common than underdiagnosis. Overdiagnosed cases were significantly associated with main pancreatic duct dilation (>5 mm) (p=0.012) and elevated amylase levels (p=0.031), while the only upgraded case involved invasive carcinoma withmural nodule and Sonazoid enhancement. Histological grade strongly influenced prognosis: Patients with adenoma or carcinoma in situ showed favorable outcomes (5-year OS ≥89%), whereas those with invasive IPMN hadmarkedly worse survival (5-year OS 36%; p<0.001). Elevated CA19-9 was a significant negative prognostic factor (p=0.031), while lymph node metastasis (p=0.035) and advanced tumor stage (p=0.0014) were also associated with poor outcomes. Tumors located in the pancreatic tail and those classified as mixed-type IPMN tended to have inferior survival, though without statistical significance. Cancer recurrence occurred in 18% of patients, primarily via peritoneal and hepatic routes. Conclusion: Preoperative diagnostic inaccuracies remain common in IPMN, and invasive transformation, elevated CA19-9, lymph node metastasis, and tumor stage are key prognostic factors. A multimodal diagnostic approach is needed to improve risk stratification and guide appropriate surgical management.
DOI： 10.21873/cdp.10528
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Nanashima Atsushi, Imamura Naoya, Hiyoshi Masahide, Tsuchimochi Yuki, Wada Takashi, Hamada Takeomi, Suzuki Yasuyuki, Araki Yuusuke, Hosokawa Ayumu, Kawakami Hiroshi
Cancer diagnosis & prognosis 6 ( 2 ) 291 - 302 2026.3
Language：English Publishing type：Research paper (scientific journal) Publisher：International Institute of Anticancer Research
Background/Aim
Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a precursor lesion with variable malignant potential. Due to its heterogeneity, optimal treatment strategies remain controversial, especially regarding surgical resection and surveillance indications. We reviewed our institutional outcomes to reassess the current postoperative strategy and refine management guidelines.
Patients and Methods
This study retrospectively and consecutively analyzed the data of 49 IPMN patients who underwent pancreatectomy at an academic institution from 2015 to May 2025.
Results
Diagnostic mismatch between preoperative and final pathological findings was observed in 39% of cases, with overdiagnosis (downgrade group) being more common than underdiagnosis. Overdiagnosed cases were significantly associated with main pancreatic duct dilation (>5 mm) (p=0.012) and elevated amylase levels (p=0.031), while the only upgraded case involved invasive carcinoma with mural nodule and Sonazoid enhancement. Histological grade strongly influenced prognosis: Patients with adenoma or carcinoma in situ showed favorable outcomes (5-year OS ≥89%), whereas those with invasive IPMN had markedly worse survival (5-year OS 36%; p<0.001). Elevated CA19-9 was a significant negative prognostic factor (p=0.031), while lymph node metastasis (p=0.035) and advanced tumor stage (p=0.0014) were also associated with poor outcomes. Tumors located in the pancreatic tail and those classified as mixed-type IPMN tended to have inferior survival, though without statistical significance. Cancer recurrence occurred in 18% of patients, primarily via peritoneal and hepatic routes.
Conclusion
Preoperative diagnostic inaccuracies remain common in IPMN, and invasive transformation, elevated CA19-9, lymph node metastasis, and tumor stage are key prognostic factors. A multimodal diagnostic approach is needed to improve risk stratification and guide appropriate surgical management. -
Nanashima Atsushi, Hiyoshi Masahide, Imamura Naoya, Tsuchimochi Yuki, Wada Takashi, Hamada Takeomi, Suzuki Yasuto, Araki Yuusuke
Cancer diagnosis & prognosis 6 ( 1 ) 52 - 61 2026.1
Language：English Publishing type：Research paper (scientific journal) Publisher：International Institute of Anticancer Research
Background/Aim
Pancreatic neuroendocrine tumors (PanNETs) are heterogeneous neoplasms for which surgical resection remains the only potentially curative therapy. However, preoperative diagnostic accuracy - particularly tumor grading - often varies, complicating treatment decisions. This study evaluated diagnostic concordance between preoperative assessments and postoperative pathology, as well as surgical outcomes and prognostic factors in patients undergoing pancreatectomy for PanNETs.
Patients and Methods
We retrospectively reviewed the clinical records of 32 patients who underwent surgical resection for PanNETs. Patient demographics, tumor characteristics, surgical procedures, and postoperative outcomes were analyzed. Preoperative imaging and cytology-based diagnoses were compared with final pathological findings to evaluate diagnostic concordance. Prognostic factors were assessed using Kaplan-Meier survival analysis.
Results
Histological grading of resected specimens showed G1 in 53%, G2 in 41%, and G3/NEC in 6%, with a 38% discordance rate from preoperative biopsy. Lymphatic, venous, and perineural invasions were identified in 16%, 44%, and 13% of cases. Lymph node metastasis occurred in 22%. Among 30 patients with follow-up >12 months, eight developed recurrence, most commonly in the liver. The 3-year and 5-year disease-free survival (DFS) rates were 78% and 69%, while overall survival (OS) rates were 96% and 91%. Tumor number >2 and histologic grade G3 were significantly associated with reduced DFS (p<0.05). Lymphatic invasion and metachronous liver metastasis were significantly associated with reduced OS (p<0.01 and p<0.05, respectively). Histological grading mismatch was not associated with survival outcomes.
Conclusion
Pancreatectomy for PanNETs is a safe and effective treatment with favorable long-term outcomes. Histological factors such as tumor grade, lymphatic invasion, and tumor number significantly predict recurrence and survival. -
Nanashima A., Hiyoshi M., Imamura N., Tsuchimochi Y., Wada T., Hamada T., Suzuki Y., Araki Y.
Cancer Diagnosis and Prognosis 6 ( 1 ) 52 - 61 2026.1
Language：English Publishing type：Research paper (scientific journal) Publisher：Cancer Diagnosis and Prognosis
Background/Aim: Pancreatic neuroendocrine tumors (PanNETs) are heterogeneous neoplasms for which surgical resection remains the only potentially curative therapy. However, preoperative diagnostic accuracy – particularly tumor grading – often varies, complicating treatment decisions. This study evaluated diagnostic concordance between preoperative assessments and postoperative pathology, as well as surgical outcomes and prognostic factors in patients undergoing pancreatectomy for PanNETs. Patients and Methods: We retrospectively reviewed the clinical records of 32 patients who underwent surgical resection for PanNETs. Patient demographics, tumor characteristics, surgical procedures, and postoperative outcomes were analyzed. Preoperative imaging and cytology-based diagnoses were compared with final pathological findings to evaluate diagnostic concordance. Prognostic factors were assessed using Kaplan–Meier survival analysis. Results: Histological grading of resected specimens showed G1 in 53%, G2 in 41%, and G3/NEC in 6%, with a 38% discordance rate from preoperative biopsy. Lymphatic, venous, and perineural invasions were identified in 16%, 44%, and 13% of cases. Lymph node metastasis occurred in 22%. Among 30 patients with follow-up >12 months, eight developed recurrence, most commonly in the liver. The 3-year and 5-year disease-free survival (DFS) rates were 78% and 69%, while overall survival (OS) rates were 96% and 91%. Tumor number >2 and histologic grade G3 were significantly associated with reduced DFS (p<0.05). Lymphatic invasion and metachronous liver metastasis were significantly associated with reduced OS (p<0.01 and p<0.05, respectively). Histological grading mismatch was not associated with survival outcomes. Conclusion: Pancreatectomy for PanNETs is a safe and effective treatment with favorable long-term outcomes. Histological factors such as tumor grade, lymphatic invasion, and tumor number significantly predict recurrence and survival.
DOI： 10.21873/cdp.10506
MISC 【 display / non-display 】
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Rare resected eight cases of duodenal adenocarcinomas. Reviewed
Nanashima Atsushi, Tanoue Yukinori, Imamura Naoya, Yano Koichi, Hamada Takeomi, Nishida Takahiro, Kai Kengo, Suzuki Yasuto, Sato Yuichiro, Nakashima Koji, Hosokawa Ayumu, Nagayasu Takeshi, Hiyoshi Masahide
International journal of surgery case reports 86 106384 2021.9
Language：English Publishing type：Rapid communication, short report, research note, etc. (scientific journal)
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胆管内腔発育型腫瘍の概念と実態：表層進展型胆道系腫瘍． Invited Reviewed
濵田剛臣，矢野公一，今村直哉，旭吉雅秀，藤井義郎，七島篤志
肝胆膵 75 ( 6 ) 1151 - 1158 2017.12
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (scientific journal)
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十二指腸乳頭部癌−現状の問題点と今後の展望−：経十二指腸的乳頭部切除の手技と適応． Invited Reviewed
今村直哉，七島篤志，濵田剛臣，矢野公一，旭吉雅秀，藤井義郎，武野慎祐，池田拓人，河野文彰，久保田良政，坂 哲臣，河上 洋
胆と膵 38 ( 7 ) 691 - 696 2017.7
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (scientific journal)
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胆膵内視鏡自由自在〜基本手技を学び応用力をつける集中講座〜：ERCP関連手技編 乳頭処置 Bridge to Surgery 悪性肝門部領域胆管閉塞． Invited Reviewed
河上 洋，久保田良政，今村直哉，旭吉雅秀，藤井義郎，七島篤志
胆と膵 37 ( (臨増特大) ) 1279 - 1285 2016.11
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (scientific journal)
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新たに定義された“肝門部領域胆管癌”の診断と治療: 術前胆道ドレナージ-経皮経肝胆道ドレナージ-. (共著)
藤井義郎，濱田朗子，西田卓弘，土持有貴，濱田剛臣，矢野公一，今村直哉，土屋和代，河野文彰，旭吉雅秀，大内田次郎，池田拓人，七島篤志
胆と膵 37 ( 1 ) 71 - 74 2016.1
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (scientific journal) Publisher：医学図書出版(株)
Presentations 【 display / non-display 】
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計画的二期的手術にて加療した外傷性膵十二指腸損傷の1例．
荒木裕介，今村直哉，河野文彰，濵田剛臣，土持有貴，和田 敬，鈴木康人，池ノ上実，宗像 駿，樋口和宏，千代反田顕，岩本和樹，武野慎祐，落合秀信，七島篤志
第17回日本Acute Care Suregery学会学術集会
Event date： 2025.9.19 - 2025.9.20
Language：Japanese Presentation type：Oral presentation (general)
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2期的に膵頭十二指腸切除術を施行したウシ外傷の1例．
荒木裕介，今村直哉，土持有貴，和田 敬，鈴木康人，濵田剛臣，河野文彰，池ノ上実，宗像 駿，樋口和宏，千代反田顕，岩本和樹，武野慎祐，落合秀信，七島篤志
令和8年度宮崎県外科医会夏期講習会(日本臨床外科学会地方会)
Event date： 2025.8.1
Language：Japanese Presentation type：Oral presentation (general)
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同時多発した2つの大型肝細胞癌を段階的に治療し2病変とも切除した1例.
山﨑泰司，七島篤志，和田 敬，土持有貴，濵田剛臣，今村直哉
第61回九州外科学会
Event date： 2025.2.8
Language：Japanese Presentation type：Oral presentation (general)
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腫瘤形成型肝内胆管癌における FDG-PET の有用性．
今村直哉，七島篤志，和田 敬，土持有貴，濵田剛臣
第45回九州肝臓外科研究会学術集会
Event date： 2025.1.18
Language：Japanese Presentation type：Oral presentation (general)
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膵管癒合不全による慢性膵炎に対して膵管空腸側々吻合術を施行した十二指腸閉鎖術後の１例.
中目和彦，川野正人，桝屋隆太，和田 敬，土持有貴，濵田剛臣，三好きな,白井 剛,今村直哉,旭吉雅秀,武野慎祐,七島篤志
第43回日本小児内視鏡外科・手術手技研究会
Event date： 2024.10.24 - 2024.10.25
Language：Japanese Presentation type：Oral presentation (general)