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Dive into the research topics where Koji Komeda is active.

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Featured researches published by Koji Komeda.


British Journal of Surgery | 2011

Impact of single-port cholecystectomy on postoperative pain.

Mitsuhiro Asakuma; Michihiro Hayashi; Koji Komeda; Tetsunosuke Shimizu; Fumitoshi Hirokawa; Yoshiharu Miyamoto; Junji Okuda; Nobuhiko Tanigawa

This study compared postoperative pain following four‐port laparoscopic cholecystectomy (LC) and single‐port cholecystectomy (SPC).


BMC Surgery | 2010

Clinicopathological analysis of recurrence patterns and prognostic factors for survival after hepatectomy for colorectal liver metastasis

Michihiro Hayashi; Yoshihiro Inoue; Koji Komeda; Tetsunosuke Shimizu; Mitsuhiro Asakuma; Fumitoshi Hirokawa; Yoshiharu Miyamoto; Junji Okuda; Atsushi Takeshita; Yuro Shibayama; Nobuhiko Tanigawa

BackgroundHepatectomy is recommended as the most effective therapy for liver metastasis from colorectal cancer (CRCLM). It is crucial to elucidate the prognostic clinicopathological factors.MethodsEighty-three patients undergoing initial hepatectomy for CRCLM were retrospectively analyzed with respect to characteristics of primary colorectal and metastatic hepatic tumors, operation details and prognosis.ResultsThe overall 5-year survival rate after initial hepatectomy for CRCLM was 57.5%, and the median survival time was 25 months. Univariate analysis clarified that the significant prognostic factors for poor survival were depth of primary colorectal cancer (≥ serosal invasion), hepatic resection margin (< 5 mm), presence of portal vein invasion of CRCLM, and the presence of intra- and extrahepatic recurrence. Multivariate analysis indicated the presence of intra- and extrahepatic recurrence as independent predictive factors for poor prognosis. Risk factors for intrahepatic recurrence were resection margin (< 5 mm) of CRCLM, while no risk factors for extrahepatic recurrence were noted. In the subgroup with synchronous CRCLM, the combination of surgery and adjuvant chemotherapy controlled intrahepatic recurrence and improved the prognosis significantly.ConclusionsOptimal surgical strategies in conjunction with effective chemotherapeutic regimens need to be established in patients with risk factors for recurrence and poor outcomes as listed above.


Surgery | 2011

A novel method using the VIO soft-coagulation system for liver resection

Fumitoshi Hirokawa; Michihiro Hayashi; Yoshiharu Miyamoto; Mitsuhiko Iwamoto; Ichiro Tsunematsu; Mitsuhiro Asakuma; Tetsunosuke Shimizu; Koji Komeda; Yoshihiro Inoue; Nobuhiko Tanigawa

BACKGROUND The VIO soft-coagulation system (SCS) is a new device for tissue coagulation. The current study evaluated the efficacy of the SCS when used for liver resection. METHODS The 252 patients were divided into 2 groups; in 155 patients (conventional group), liver transection was performed using an ultrasonic dissector and saline-coupled bipolar electrocautery for hemostasis. In 97 patients (SCS group), the SCS was used instead of bipolar electrocautery. RESULTS The median blood loss and surgical time were less in the SCS group than in the conventional group (350 vs 640 mL, P = .0028; 280 vs 398 min, P < .0001). No significant differences were found in postoperative complications between the SCS group (32.0%) and the conventional group (40.6%). The risk factors for bleeding were nonuse of the SCS (P = .0039), macroscopic vascular invasion of the hepatic tumors (P = .0088), and collagen type IV value in the sera >200 (P = .0250) on multivariate analysis. In a subgroup analysis, in the collagen type IV value >200 subgroup, the tumor diameter >5 cm subgroup, and the inflow nonocclusion subgroup, use of the SCS decreased surgical bleeding (P = .0120, P = .0126, and P = .0032, respectively) and surgical time (P = .0001, P < .0001, and P = .0036, respectively) compared with the conventional group. Furthermore, even in the major hepatectomy group, the SCS use decreased surgical time (P < .0001). CONCLUSION The SCS is an effective and safe device for decreasing surgical time and surgical bleeding without increasing the rate of bile leakage and causing other complications.


Hepatology Research | 2014

Outcomes and predictors of microvascular invasion of solitary hepatocellular carcinoma

Fumitoshi Hirokawa; Michihiro Hayashi; Yoshiharu Miyamoto; Mitsuhiro Asakuma; Tetsunosuke Shimizu; Koji Komeda; Yoshihiro Inoue; Kazuhisa Uchiyama

Microvascular invasion (MVI) is an important risk factor for early recurrence of hepatocellular carcinoma (HCC), but preoperative prediction of MVI is difficult.


Hepatology Research | 2008

Significance of chymase-dependent angiotensin II formation in the progression of human liver fibrosis

Koji Komeda; Denan Jin; Shinji Takai; Michihiro Hayashi; Atsushi Takeshita; Yuro Shibayama; Nobuhiko Tanigawa; Mizuo Miyazaki

Aim:  Angiotensin II may contribute to liver fibrogenesis. In addition to angiotensin‐converting enzyme (ACE), chymase, which is expressed by mast cells, is also known to be an angiotensin II‐forming enzyme. However, it is unclear which of these two angiotensin II‐forming enzymes plays a more important role in liver cirrhosis progression. In the present study, the role of angiotensin II‐forming enzymes in the progression of liver cirrhosis was clarified.


Hepatology Research | 2010

Chymase inhibition attenuates tetrachloride-induced liver fibrosis in hamsters

Koji Komeda; Shinji Takai; Denan Jin; Keitaro Tashiro; Michihiro Hayashi; Nobuhiko Tanigawa; Mizuo Miyazaki

Aim:  Chymase converts angiotensin I to angiotensin II, which may promote the development of liver fibrosis. In this study, whether a chymase inhibitor TY‐51469 attenuated tetrachloride (CCl4)‐induced liver fibrosis was examined.


Hepatology Research | 2010

Chymase inhibitor prevents the nonalcoholic steatohepatitis in hamsters fed a methionine- and choline-deficient diet.

Keitaro Tashiro; Shinji Takai; Denan Jin; Hiromi Yamamoto; Koji Komeda; Michihiro Hayashi; Kazuhiko Tanaka; Nobuhiko Tanigawa; Mizuo Miyazaki

Aim:  Mast cells may be involved in the pathogenesis of nonalcoholic steatohepatitis (NASH). The mast cell protease chymase contributes to the formation of angiotensin II and matrix metalloproteinase (MMP)‐9, both of which are intimately involved in liver fibrosis. Therefore, we hypothesized that chymase plays an important role in the development of NASH.


International Surgery | 2011

Simultaneous laparoscopic resection of colorectal cancer and synchronous metastatic liver tumor.

Michihiro Hayashi; Koji Komeda; Yoshihiro Inoue; Tetsunosuke Shimizu; Mitsuhiro Asakuma; Fumitoshi Hirokawa; Junji Okuda; Keitaro Tanaka; Keisaku Kondo; Nobuhiko Tanigawa

Laparoscopic colorectal resection has been applied to advanced colorectal cancer. Synchronous liver metastasis of colorectal cancer would be treated safely and effectively by simultaneous laparoscopic colorectal and hepatic resection. Seven patients with colorectal cancer and synchronous liver metastasis treated by simultaneous laparoscopic resection were analyzed retrospectively. Three patients received a hybrid operation using a small skin incision, 2 patients underwent hand-assisted laparoscopic surgery using a small incision produced for colonic anastomosis, and 2 patients were treated with pure laparoscopic resection. The mean total operation duration was 407 minutes, and mean blood loss was 207 mL. Negative surgical margins were achieved in all cases. Mean postoperative hospital stay was 16.4 days. No recurrence at the surgical margin was observed in the liver. For selected patients with synchronous liver metastasis of colorectal cancer, simultaneous laparoscopic resection is useful for minimizing operative invasiveness while maintaining safety and curability, with satisfying short- and long-term results.


Annals of Transplantation | 2012

A case of gastric cancer after living donor liver transplantation.

Tetsunosuke Shimizu; Michihiro Hayashi; Yoshihiro Inoue; Koji Komeda; Mitsuhiro Asakuma; Fumitoshi Hirokawa; Yoshiharu Miyamoto; Nobuhiko Tanigawa; Kazuhisa Uchiyama

BACKGROUND As newer immunosuppressive regimens have steadily reduced in the incidence of acute rejection and have extended the life expectancy of allograft recipients, posttransplant de novo malignancies have become an important cause of death in cadaveric donor transplantation. Also, according with the recent accumulation of living donor liver transplantation (LDLT), the number of posttransplant recipients with de novo malignancy will be anticipated to increase. CASE REPORT A 60 year-old man underwent LDLT for hepatitis C virus-related cirrhosis with hepatocellular carcinoma. Thirty months after LDLT, he was found to have gastric cancer by upper gastrointestinal endoscopy. He underwent segmental gastrectomy with lymph node dissection. Histopathological examination of the explanted stomach revealed poorly differentiated adenocarcinoma with subserosal invasion in the gastric wall and perigastric lymph node metastasis. Three years and eight months after the gastric surgery, the patient is alive with no recurrence of gastric cancer or HCC under no adjuvant chemotherapy. CONCLUSIONS Considering that early detection is the only key in curing cancer in general, we should make effort to detect cancer in their early stage, especially in case of LDLT recipients.


World Journal of Gastrointestinal Surgery | 2010

Surgical treatment for abdominal actinomycosis: A report of two cases

Michihiro Hayashi; Mitsuhiro Asakuma; Soichiro Tsunemi; Yoshihiro Inoue; Tetsunosuke Shimizu; Koji Komeda; Fumitoshi Hirokawa; Atsushi Takeshita; Yutaro Egashira; Nobuhiko Tanigawa

Since actinomycosis sometimes causes an abdominal tumor which mimics malignancy, treatment strategy varies from case to case. We herein report two cases which were treated with a combination of antibiotics and surgical intervention. Both patients presented with an intra-abdominal tumor lesion mimicking malignant disease after an appendectomy for acute appendicitis. Case 1 received surgical extirpation of the abdominal tumor in the liver and kidney twice since the clinical diagnosis of actinomycosis was not made. In contrast, case 2 was successfully treated by a combination of antibiotics and laparoscopic surgery following the experience of case 1. When a high probability diagnosis can be made, a laparoscopic approach is a useful and effective option to treat this condition.

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Kazuhisa Uchiyama

Wakayama Medical University

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Denan Jin

Osaka Medical College

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