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Dive into the research topics where Kentaro Yamagiwa is active.

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Featured researches published by Kentaro Yamagiwa.


American Journal of Surgery | 2002

Analysis of the relationships between clinicopathologic factors and survival time in intrahepatic cholangiocarcinoma

Yoshifumi Kawarada; Kentaro Yamagiwa; Bidhan C. Das

BACKGROUND This study elucidated the relationships between various clinicopathologic factors and the outcome of patients with intrahepatic cholangiocarcinoma (ICC) treated by hepatic resection. METHODS A total of 37 ICC patients were treated by hepatic resection in our department between March 1979 and March 2001. Eleven clinicopathological variables (age, sex, preoperative jaundice, operative curability, number of tumors, UICC [Union Internationale Contre le Cancer] pT factor, UICC pN factor, UICC pM factor, histological tumor type, 10-year period during which they initially examined, and adjuvant therapy) were selected for univariate and multivariate analysis to evaluate their influence on the outcome. RESULTS The actuarial 1-, 3-, and 5-year survival rates in the 37 resected cases were 54.1%, 34.0%, and 23.9%, respectively. The stage of the ICC influenced their overall survival rate. The univariate analysis revealed that curative resection (P = 0.0018), UICC pT factor (P = 0.0445), pN factor (P = 0.0029), pM factor (P = 0.0022), and histological type (P = 0.0030) were significant risk factors for survival. Multivariate analysis revealed that noncurative resection, lymph node metastasis, and less differentiated histological type were significant risk factors for poor outcome. All 6 of the 37 patients who survived more than 5 years had undergone curative resection, all of their tumors were well differentiated, and none had lymph node metastasis. CONCLUSIONS Curative surgical resection remains the only effective approach to the treatment of ICC. Extensive resection is not indicated if lymph node metastasis can be identified preoperatively or intraoperatively. Current adjuvant therapy is ineffective, and it will be necessary to assess the efficacy of new adjuvant therapy strategies or the addition of new agents in terms of the outcome of ICC.


Transplantation | 2006

Optimal portal venous circulation for liver graft function after living-donor liver transplantation.

Shintaro Yagi; Taku Iida; Tomohide Hori; Kentaro Taniguchi; Chizuru Yamamoto; Kentaro Yamagiwa; Shinji Uemoto

Background. Previous studies have shown poor outcome after living-donor liver transplantation (LDLT) as a result of excessive portal venous pressure (PVP), excessive portal venous flow (PVF), or inadequate PVF. We investigated optimal portal venous circulation for liver graft function after LDLT in adult recipients retrospectively. Methods. Between June 2003 and November 2004, 28 adult patients underwent LDLT in our institution. We modulated PVP under 20 mmHg in these 28 cases by performing a splenectomy (n=4) or splenorenal shunt (n=1). The PVF and PVP were measured at the end of the operation. Compliance was calculated by dividing PVF by PVP. Results. PVF and compliance showed a significant inverse correlation with peak billirubin levels after LDLT (r = -0.63: r=−0.60, P<0.01), and with peak international normalized ratio after LDLT (r=−0.41: r=−0.51, P<0.05). Compliance was higher in right-lobe graft with middle hepatic vein cases (148±27 ml/min/mmHg), and lower in left-lobe graft cases (119±50 ml/min/mmHg). Conclusions. Liver graft function was better when PVF and graft compliance were higher and PVP was maintained under 20 mmHg.


Liver Transplantation | 2006

KICG value, a reliable real‐time estimator of graft function, accurately predicts outcomes in adult living‐donor liver transplantation

Tomohide Hori; Taku Iida; Shintaro Yagi; Kentaro Taniguchi; Chiduru Yamamoto; Shugo Mizuno; Kentaro Yamagiwa; Shuji Isaji; Shinji Uemoto

Reliable monitoring enabling evaluation of graft function is crucial after living‐donor liver transplantation (LDLT). A method to identify poor graft function at an early postoperative period would allow opportune intensive clinical management to bring about further improvements in LDLT outcomes. This study assessed the reliability of the indocyanine green (ICG) elimination rate constant (KICG) value as an estimator of graft function and determined the actual temporal changes of KICG after LDLT. KICG values were measured using a noninvasive method in 30 adult recipients up to 28 days after LDLT. The receptor index (LHL15) based on liver scintigraphy, and graft parenchymal damage score based on histopathological findings were evaluated after LDLT and correlated well with simultaneous KICG. Thus, KICG measured by noninvasive method was confirmed as accurately evaluating graft function. Changes of KICG after LDLT in recipients with good graft function were maintained, after some falls in the early periods, and had a significant difference compared with those for recipients without good graft function; moreover, there were already significant differences in KICG 24 hours after LDLT. Mean transit time reflecting systemic hemodynamics revealed that recipients without good outcomes fell into an unstable systemic hemodynamic state, and effective hepatic blood flow has a large influence on liver regeneration after LDLT. In conclusion, we suggested that KICG values can predict clinical outcomes at the early postoperative period after LDLT by sharply reflecting the influence of systemic dynamics on splanchnic circulation. Liver Transpl 12:605–613, 2006.


Transplant International | 2005

Donor outcome and liver regeneration after right-lobe graft donation.

Hajime Yokoi; Shuji Isaji; Kentaro Yamagiwa; Masami Tabata; Hiroyuki Sakurai; Mosanobu Usui; Shugo Mizuno; Shinji Uemoto

Sufficiently detailed information on donor safety and the liver regeneration process following right‐lobe living donation has been unavailable, so we evaluated donor outcome and liver regeneration in 13 males and 14 females (39.0 ± 14.8 years old) who provided 27 right‐lobe grafts without the middle hepatic vein. Preoperative total liver volume (TLV), graft volume, and postoperative changes in residual liver volume (RLV) were measured by volumetric computed tomography. Histological steatosis of the liver was graded as none, minimal (≤10%), and mild (11–30%). The median follow‐up period was 337 days. Estimated graft volume and actual graft weight were linearly correlated (Y = 177.85 + 0.795X, R2 = 0.812, P < 0.0001). Graft‐to‐recipient weight ratio was 1.08 ± 0.19%. Four donors had postoperative complications, but they resolved in response to conservative treatment. Postoperative hospital stay was 15.2 ± 5.5 days. Peak liver enzyme values were significantly higher in donors with mild steatosis (n = 7) than without steatosis (n = 16) (P < 0.05). Donor RLV was 40.8 ± 6.6% of original TLV at surgery, 79.8 ± 12.0% by 6 months, and 97.2 ± 10.8% by 12 months. At 3 months the liver of the older donors (≥50 years) had grown significantly more slowly than in younger donors (70.4 ± 9.2% vs. 79.3 ± 9.6%, P = 0.0391). In conclusion, right hepatectomy without middle hepatic vein of living donors is a safe procedure with acceptable morbidity, and the residual liver regenerated to its preoperative size by 1 year. However, meticulous care should be taken in donors with liver steatosis and aged donors.


Surgery Today | 2004

Laparoscopic Spleen-Preserving Pancreatic Tail Resection for an Intrapancreatic Accessory Spleen Mimicking a Nonfunctioning Endocrine Tumor: Report of a Case

Takashi Hamada; Shuji Isaji; Shugo Mizuno; Masami Tabata; Kentaro Yamagiwa; Hajime Yokoi; Shinji Uemoto

Laparoscopic surgery is now performed for several pancreatic disorders, such as benign tumors of the pancreatic body or tail, which are a good indication for laparoscopic resection. However, the risk of pancreatic fistula after distal pancreatectomy, performed laparoscopically or by open surgery, is a topic of debate. We report the case of a 61-year-old man in whom a routine follow-up computed tomography (CT) scan showed a solid, well-defined mass, 1.5 cm in diameter, in the pancreatic tail. The mass was homogeneously enhanced from the early phase to the super-delayed phase on enhanced CT. We suspected a nonfunctioning endocrine tumor of the pancreas, and surgery was performed laparoscopically. After dissecting the pancreatic tail away from the splenic hilum and the splenic vessels, it was resected using only a linear stapler. The histological diagnosis was an intrapancreatic accessory spleen. The patient was discharged on postoperative day 14, but was readmitted 6 days later because of a pancreatic fistula, which was treated by CT-guided percutaneous drainage.


Journal of Gastroenterology and Hepatology | 2008

Survival rates according to the Cancer of the Liver Italian Program scores of 345 hepatocellular carcinoma patients after multimodality treatments during a 10-year period in a retrospective study.

Kentaro Yamagiwa; Katsuya Shiraki; Koichiro Yamakado; Shugo Mizuno; Tomohide Hori; Shinichiro Yagi; Takashi Hamada; Taku Iida; Ikuo Nakamura; Koji Fujii; Masanobu Usui; Shuji Isaji; Keiichi Ito; Shinsei Tagawa; Kan Takeda; Hajime Yokoi; Takashi Noguchi

Background and Aim:  The Cancer of the Liver Italian Program (CLIP) score has been demonstrated to have superior prognostic ability in hepatocellular carcinoma (HCC) patients worldwide, but there has never been sufficient assessment of the efficacy of treatment modalities according to the CLIP score. This retrospective cohort study of HCC patients was conducted to assess the efficacy of treatment modalities according to the CLIP score.


American Journal of Transplantation | 2004

Intrahepatic Hepatic Vein Stenosis After Living‐Related Liver Transplantation Treated by Insertion of an Expandable Metallic Stent

Kentaro Yamagiwa; Hajime Yokoi; Shuji Isaji; Masami Tabata; Shugo Mizuno; Tomohide Hori; Koichiro Yamakado; Shinji Uemoto; Kan Takeda

Although the incidence of stenosis and obstruction of the hepatic venous anastomosis after right hepatic living‐related liver transplantation (LRLT) has been found to be higher than after orthotopic liver transplantation (OLT), to the best of our knowledge, intrahepatic stenosis of the venous trunk in the early period after right hepatic LRLT has never been reported in the literature. A 53‐year‐old man who underwent right hepatic LRLT, postoperatively, developed liver dysfunction and an increasing amount of ascites, and a Doppler sonogram showed a flat waveform and low‐flow velocity in the hepatic vein. Based on these findings an outflow block was suspected, and a hepatic venogram and manometry revealed intrahepatic stenosis of a tortuous hepatic venous trunk and a pressure gradient of 14 mmHg at the site of the stenosis. We inserted an expandable metallic stent (EMS) at the site of intrahepatic venous stenosis, and its insertion was followed by a decrease in pressure gradient. Liver function recovered, and the volume of ascitic fluid decreased after placement of the EMS. The results of an analysis of the venogram and CT volumetric data suggested that the pathogenesis of the stenosis was twisting of the venous trunk during hypertrophy of the liver parenchyma.


Clinical Transplantation | 2005

Outflow block secondary to stenosis of the inferior vena cava following living-donor liver transplantation?

Shugo Mizuno; Hajime Yokoi; Kentaro Yamagiwa; Masami Tabata; Shuji Isaji; Koichiro Yamakado; Kan Takeda; Shinji Uemoto

Abstract:  Although it is well known that outflow block is caused by stenosis or occlusion of hepatic vein anastomoses following living donor liver transplantation (LDLT), there have been few reports on inferior vena cava (IVC) stenosis following LDLT. In this paper, we report two cases of IVC stenosis and hepatic vein outflow block following right hepatic LDLT in the absence of stenosis of any of the anastomoses. Both patients presented with liver dysfunction, an ascitic fluid volume of approximately 2000 mL, and congestion in their biopsy specimens, and venocavography demonstrated IVC stenosis with gradients of more than 10 mmHg in patients with a dominant inferior right hepatic vein (IRHV) anastomosis. After a Gianturco expandable metallic stent successfully implanted in the IVC, the patients liver function recovered and the volume of ascitic fluid decreased. The pathogenesis of hepatic vein outflow block secondary to IVC stenosis following LDLT may involve the anastomosis with the IRHV, which is the dominant draining vein of the graft and larger than the RHV, caudal to the IVC stenosis and a significant IVC pressure gradient that results in increased IRHV pressure. In conclusion, it is important to include hepatic vein outflow block in the differential diagnosis when patients who have undergone right hepatic LDLT in which anastomosis of the large IRHV has been performed develop manifestations of liver dysfunction.


Scandinavian Journal of Gastroenterology | 2004

Are the results of surgical treatment of hepatocellular carcinoma poor if the tumor has spontaneously ruptured

Shugo Mizuno; Kentaro Yamagiwa; Tomoko Ogawa; Masami Tabata; Hajime Yokoi; S. Isaji; Shinji Uemoto

Background: The aim of this study was to clarify whether the results of surgical treatment of ruptured hepatocellular carcinoma (HCC) are poorer than the results of surgical treatment of non‐ruptured HCC. Methods: Out of a total of 224 HCC patients, the 6 patients with ruptured HCC were compared with 15 patients with non‐ruptured HCC based on TNM stage IVA and having a Cancer of the Liver Italian Program (CLIP) score of 1 or 2. Results: There were no significant differences in clinical and pathological features between the two groups. The 1‐year and 3‐year overall survival rates were 69.3% and 21.2%, respectively, in the ruptured HCC group and 51.3% and 20.5%, respectively, in the non‐ruptured HCC group. The 1‐year and 3‐year disease‐free survival rates were 33.0% and 0%, respectively, in the ruptured HCC group and 38.9% and 15.6%, respectively, in the non‐ruptured HCC group. The differences in survival rates between these two groups did not reach statistical significance. Conclusion: Hepatic resection as definitive treatment after recovery from the initial insult of the rupture of HCC yields results similar to those obtained by surgical treatment of non‐ruptured HCC at the same tumor stage and with the same degree of liver damage.


Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 2003

Laparoscopic splenectomy for a huge splenic cyst without preoperative drainage: report of a case.

Shintaro Yagi; Shuji Isaji; Taku Iida; Shugo Mizuno; Masami Tabata; Kentaro Yamagiwa; Hajime Yokoi; Hiroshi Imai; Shinji Uemoto

Laparoscopic splenectomy currently is a safe procedure and offers better cosmetic results, less pain, and a shorter hospital stay than the traditional open procedure. However, there have been only a few reports of laparoscopic removal of giant splenic cysts. An 18-year-old woman was admitted with abdominal fullness. CT scans and MRI images of the upper abdomen revealed a cystic mass having a diameter of 19 cm. Preoperative diagnosis was a large splenic cyst, and laparoscopic splenectomy with intraoperative cyst drainage (amount of drained fluid: 3,000 mL) was performed. Histologically, almost the entire cyst wall was lined with fibrous tissue, but a small portion was covered with stratified squamous epithelium. The final diagnosis was epidermoid cyst. The postoperative course was uneventful. Laparoscopic splenectomy should be tried first even in patients with a huge cyst, and intraoperative drainage under laparoscopic guidance facilitates laparoscopic splenectomy.

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