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Featured researches published by Keisuke Okamura.


Surgery | 2016

A new prognostic scoring system using factors available preoperatively to predict survival after operative resection of perihilar cholangiocarcinoma

Hiroki Saito; Takehiro Noji; Keisuke Okamura; Takahiro Tsuchikawa; Toshiaki Shichinohe; Satoshi Hirano

BACKGROUND Perihilar cholangiocarcinoma has one of the poorest prognoses of all cancers. However, mortality and morbidity rates after surgical resection are 0-15% and 14-66%, respectively. Additionally, the 5-year overall survival rates are reported at 22-40%. These findings indicate that only selected patients achieve satisfactory beneficial effects from operative treatment. This retrospective study sought to investigate preoperatively available prognostic factors and establish a new preoperative staging system to predict survival after major hepatectomy of perihilar cholangiocarcinoma. PATIENTS AND METHODS We evaluated 121 consecutive patients who underwent operative exploration for perihilar cholangiocarcinoma. RESULTS Univariate and multivariate analysis using the identified preoperative factors revealed that 4 factors (platelet-lymphocyte ratio [PLR] > 150, serum C-reactive protein [CRP] levels > 0.5 mg/dL, albumin levels < 3.5 g/dL, and carcinoembryonic antigen [CEA] levels > 7.0 ng/mL) were independent prognostic factors of postoperative survival. These 4 preoperative factors were allocated 1 point each. The total score was defined as the Preoperative Prognostic Score (PPS). Patients with a PPS of 0, 1, 2, or 3/4 had a 5-year survival of 84.3%, 51.3%, 46.4%, and 0%, respectively. There were also differences in the 5-year survival according to the PPS (0 vs 1 [P = .013] and 2 vs 3/4 [P < .001]). Patients with a total PPS of 3/4 had a dismal prognosis, with a median survival of 11.3 months. CONCLUSION A new preoperative scoring system using PLR, serum CRP, albumin, and CEA levels could predict postoperative survival resection of perihilar cholangiocarcinoma.


Surgery Today | 2012

Laparoscopic pancreaticoduodenectomy combined with minilaparotomy

On Suzuki; Satoshi Kondo; Satoshi Hirano; Eiichi Tanaka; Kentaro Kato; Takahiro Tsuchikawa; Tomoyuki Yano; Keisuke Okamura; Toshiaki Shichinohe

Laparoscopic pancreatic surgery is evolving rapidly; however, the surgical treatment of periampullary tumors is still fraught with challenges, such as technical difficulty and the appropriateness of oncologic treatment for these patients. We describe how we performed laparoscopic pancreaticoduodenectomy (LPD) combined with minilaparotomy successfully in six consecutive patients. This procedure consisted of two surgical phases: safe laparoscopic surgery, including the Kocher maneuver, tunneling behind the pancreatic neck, and dissecting along the uncinate process with magnified vision; and a secure open approach with complete skeletonization of the hepatoduodenal ligament and alimentary tract reconstruction, performed similarly to conventional pancreaticoduodenectomy, under direct visualization through the minilaparotomy. By performing this procedure, we combined a safe and secure minilaparotomy approach under direct vision with a less invasive laparoscopic approach providing a magnified image. Our experience demonstrates that LPD combined with minilaparotomy is technically feasible for selected patients with periampullary tumors.


Journal of Hepato-biliary-pancreatic Sciences | 2016

Preoperative diagnosis of portal vein invasion in pancreatic head cancer: appropriate indications for concomitant portal vein resection

Koichi Teramura; Takehiro Noji; Toru Nakamura; Toshimichi Asano; Kimitaka Tanaka; Yoshitsugu Nakanishi; Takahiro Tsuchikawa; Keisuke Okamura; Toshiaki Shichinohe; Satoshi Hirano

The surgical indications for patients with pancreatic head cancer (PHC) with clinical portal vein (PV) invasion (cPV) remain controversial. The present study aimed to determine the ability of computed tomography (CT) to diagnose pathological PV involvement (pPV) in PHC.


Expert Review of Gastroenterology & Hepatology | 2015

Advances in the surgical treatment of hilar cholangiocarcinoma

Takahiro Tsuchikawa; Satoshi Hirano; Keisuke Okamura; Joe Matsumoto; Eiji Tamoto; Soichi Murakami; Toru Nakamura; Yuma Ebihara; Yo Kurashima; Toshiaki Shichinohe

With the improvement of perioperative management and surgical techniques as well as the accumulation of knowledge on the oncobiological behavior of bile duct carcinoma, the long-term prognosis of hilar cholangiocarcinoma has been improving. In this article, the authors review the recent developments in surgical strategies for hilar cholangiocarcinoma, focusing on diagnosis for characteristic disease extension, perioperative management to reduce postoperative morbidity and mortality, surgical techniques for extended curative resection and postoperative adjuvant therapy.


Journal of Hepato-biliary-pancreatic Sciences | 2016

Concomitant hepatic artery resection for advanced perihilar cholangiocarcinoma: a case-control study with propensity score matching.

Takehiro Noji; Takahiro Tsuchikawa; Keisuke Okamura; Kimitaka Tanaka; Yoshitsugu Nakanishi; Toshimichi Asano; Toru Nakamura; Toshiaki Shichinohe; Satoshi Hirano

Whether concomitant hepatic artery resection (HAR) improves the prognosis for advanced perihilar cholangiocarcinoma remains controversial. The aim of the present study was to compare short‐ and long‐term surgical results of HAR versus standard resection (SR) for perihilar cholangiocarcinoma using propensity score matching.


Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 2015

Strategic Approach to the Splenic Artery in Laparoscopic Spleen-preserving Distal Pancreatectomy.

Kazuho Inoko; Yuma Ebihara; Keita Sakamoto; N. Miyamoto; Yo Kurashima; Eiji Tamoto; Toru Nakamura; Soichi Murakami; Takahiro Tsuchikawa; Keisuke Okamura; Toshiaki Shichinohe; Satoshi Hirano

Background: Laparoscopic spleen-preserving distal pancreatectomy (LSPDP) is an ideal procedure in selected patients with benign or low-grade malignant tumors in the body/tail of the pancreas. We describe our procedure and experience with splenic vessel-preserving LSPDP (SVP-LSPDP) in a retrospective case series. Methods: Six consecutive patients underwent SVP-LSPDP from January 2011 to September 2013. We evaluated the courses of the splenic artery by preoperative computed tomography and applied an individualized approach (the superior approach or inferior approach) to the splenic artery. Results: All of the operations were successful. The median surgical duration was 249 minutes. The median blood loss was 0 mL. Pathologic examination revealed 4 cases of insulinoma, 1 case of solid pseudopapillary tumor, and 1 case of pancreatic metastasis from renal carcinoma. Conclusions: In performing SVP-LSPDP, it is effective to make a strategic choice between 2 different approaches according to the course of splenic artery.


Pancreas | 2003

Autonomic nerve changes in the mouse pancreas after pancreatic duct ligation

Keisuke Okamura; Satoshi Watanabe; Kazuhiro Abe; Satoshi Kondo; Hiroyuki Katoh

Introduction The mouse pancreas exhibits distinct atrophy of the exocrine tissue following pancreatic duct ligation. Aim To investigate changes of innervation in the whole pancreas after pancreatic duct ligation. Methodology The mouse pancreatic duct was ligated at 6 weeks of age. Pancreatic tissues were removed 7 days and 14 days after the ligation, fixed by perfusion and immersion with Zamboni solution, and embedded in gelatin. The whole organ was serially sectioned at a thickness of 100 &mgr;m, histochemically stained for cholinesterase, and observed by light microscopy. The number and volume of intrapancreatic ganglia, number of ganglion cells, and volume of each ganglion cell in the whole pancreas were quantitated. Some sections were analyzed using transmission electron microscopy after histochemically staining for cholinesterase. Results In the normal pancreas, ganglia were often situated on the outer surface of the islets of Langerhans. Thick nerve bundles ran along the arteries and emanated thin nerve fibers that surrounded the arterioles. In the atrophied pancreas following pancreatic duct ligation, ganglia remained on the islets of Langerhans as in normal mice, while the nerve fibers appeared dense, bending and curling in a more complex manner. The thin nerves also crossed each other in a complex network. Using morphometry in the pancreas following pancreatic duct ligation, the total ganglion cell number was found to decrease from normal levels. The mean ganglion cell volume in the ligated pancreas was significantly smaller than that in normal mice. As observed by transmission electron microscopy, some ganglion cells in the ligated pancreas were negative for cholinesterase activity but were surrounded by positive staining around the surface. Conclusions These results suggest that the function of pancreatic ganglion cells changes with organ atrophy after pancreatic duct ligation.


Journal of Hepato-biliary-pancreatic Sciences | 2017

Randomized controlled trial of perioperative antimicrobial therapy based on the results of preoperative bile cultures in patients undergoing biliary reconstruction.

K. Okamura; Kimitaka Tanaka; Takumi Miura; Yoshitsugu Nakanishi; Takehiro Noji; Toru Nakamura; Takahiro Tsuchikawa; Keisuke Okamura; Toshiaki Shichinohe; Satoshi Hirano

The high frequency of surgical site infections (SSIs) after hepato‐pancreato‐biliary (HPB) surgery is a problem that needs to be addressed. This prospective, randomized, controlled study examined whether perioperative prophylactic use of antibiotics based on preoperative bile culture results in HPB surgery could decrease SSI.


World Journal of Surgical Oncology | 2015

Potential risk of residual cancer cells in the surgical treatment of initially unresectable pancreatic carcinoma after chemoradiotherapy

Hironobu Takano; Takahiro Tsuchikawa; Toru Nakamura; Keisuke Okamura; Toshiaki Shichinohe; Satoshi Hirano

BackgroundWith development of chemoradiotherapy for pancreatic carcinoma, borderline resectable or initially unresectable cases sometimes become operable after long-term intensive chemoradiotherapy. However, there is no established strategy for adjuvant surgery with respect to whether the surgical resection should be extensive or downsized accordingly with diminished disease areas following response to chemoradiotherapy.MethodsThe clinical and pathological aspects of 18 patients with initially unresectable pancreatic cancer who underwent adjuvant surgery after chemo(radio)therapy in our department from 2007 were evaluated.ResultsOverall survival from initial treatment was much better for patients with R0 resection than for patients with R1/2 resection. In two of three patients who had complete improvement of plexus (PL) invasion after chemo(radio)therapy, there had still remained pathological plexus invasion. It was shown that tumors did not shrink continuously from the tumor front, but parts remained discontinuously at the distal portion in the process of tumor regression by chemo(radio)therapy.ConclusionsIn adjuvant surgery for patients with locally advanced pancreatic cancer, the potential risk of residual cancer in the regression area following chemoradiotherapy should be considered. Achieving R0 resection will lead to an improved prognosis, and it is necessary to consider how well the extent of resection is after a favorable response to chemoradiotherapy.


World Journal of Gastroenterology | 2015

Hilar cholangiocarcinoma with intratumoral calcification: A case report

Kazuho Inoko; Takahiro Tsuchikawa; Takehiro Noji; Yo Kurashima; Yuma Ebihara; Eiji Tamoto; Toru Nakamura; Soichi Murakami; Keisuke Okamura; Toshiaki Shichinohe; Satoshi Hirano

This report describes a rare case of hilar cholangiocarcinoma with intratumoral calcification that mimicked hepatolithiasis. A 73-year-old man presented to a local hospital with a calcified lesion in the hepatic hilum. At first, hepatolithiasis was diagnosed, and he underwent endoscopic stone extraction via the trans-papillary route. This treatment strategy failed due to biliary stricture. He was referred to our hospital, and further examination suggested the existence of cholangiocarcinoma. He underwent left hepatectomy with caudate lobectomy and extrahepatic bile duct resection. Pathological examination revealed hilar cholangiocarcinoma with intratumoral calcification, while no stones were found. To the best of our knowledge, only one case of calcified hilar cholangiocarcinoma has been previously reported in the literature. Here, we report a rare case of calcified hilar cholangiocarcinoma and reveal its clinicopathologic features.

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