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Featured researches published by Satoshi Ambiru.


Diseases of The Colon & Rectum | 1999

Hepatic resection for colorectal metastases: analysis of prognostic factors.

Satoshi Ambiru; Masaru Miyazaki; Toshio Isono; Hiroshi Ito; Koji Nakagawa; Hiroaki Shimizu; Kimihiko Kusashio; Seiji Furuya; Nobuyuki Nakajima

PURPOSE: Hepatic resection affords the best hope of survival for patients with colorectal carcinoma metastatic to the liver. However, recurrences are observed in about 60 percent of patients after curative hepatic resection. The purpose of this study was to examine the prognostic factors of patients undergoing curative hepatic resection for colorectal metastases. METHODS: Between April 1984 and September 1997, 168 patients underwent curative hepatic resection for colorectal metastases. The clinicopathologic factors studied for prognostic value were gender, age, primary site, nodal status of primary tumor, time of metastases, preoperative serum level of carcinoembryonic antigen, hepatic tumor size and distribution, number of metastases, type of hepatic resection, resection margin, presence of micrometastases in resected specimen and microscopic fibrous pseudocapsule between the hepatic tumor and surrounding hepatic parenchyma, nodal status of hepatoduodenal ligament, adjuvant regional chemotherapy, and perioperative transfusion. RESULTS: The overall survival was 42 percent at three years and 26 percent at five years, including a 3.5 percent 60-day surgical mortality rate. Thirty-one percent of patients had micrometastases located at a median distance of 3 mm from the metastatic tumor edge. Presence of microscopic fibrous pseudocapsule was observed in 28 percent of patients. Univariate and multivariate analyses showed that significant prognostic factors for survival were nodal status of primary tumor, number of metastases, resection margin, microscopic fibrous pseudocapsule, and adjuvant regional chemotherapy. CONCLUSIONS: We conclude that 1) hepatic resection is effective in select patients with colorectal metastases; 2) adequate resection margin and adjuvant regional chemotherapy can improve outcome; and 3) microscopic fibrous pseudocapsule may offer additional postoperative information as an independent prognostic factor.


Surgery | 1998

Aggressive surgical approaches to hilar cholangiocarcinoma: Hepatic or local resection?

Masaru Miyazaki; Hiroshi Ito; Koji Nakagawa; Satoshi Ambiru; Hiroaki Shimizu; Yoshiaki Shimizu; Atsushi Kato; Shunta Nakamura; Hideyuki Omoto; Nobuyuki Nakajima; Fumio Kimura; Toshikazu Suwa

BACKGROUND It has been reported that surgical excision of hilar cholangiocarcinoma rather than palliative surgical therapy, chemotherapy, or radiotherapy caused prolonged survival in some patients, However, excision is associated with high operative morbidity and mortality rates, particularly when hepatic resection is also performed. The aim of this study was to evaluate the clinical implications of hepatic resection in hilar cholangiocarcinoma. METHODS The study involved 76 patients with hilar cholangiocarcinoma who were undergoing surgical resections. Twenty-one patients (28%) underwent a combined resection, with reconstruction of the portal vein in 20 patients and reconstruction of the hepatic artery in 7 patients. Sixty-five patients undergoing seven different types of hepatic resection with extrahepatic bile duct resection (BDR) and 11 patients undergoing BDR only were retrospectively compared for background, operative morbidity and mortality, and survival. RESULTS Curative resection was obtained in 5 of 11 (45%) patients undergoing local resection and in 49 of 65 (75%) patients undergoing hepatic resection (p < 0.05). The surgical morbidity rates were 34% and 27% for hepatic and local resection, respectively. The 30-day mortality and hospital mortality rates were 4.6% and 15% for hepatic resection and 0% and 0% for local resection, respectively. The 5-year survival rate was 26% for all resected patients (76 patients); it was 40% versus 0% for curative versus noncurative resections (p < 0.05). No significant difference in surgical resection rates was revealed between hepatic and local resection among resected and curative resected patients. CONCLUSIONS Aggressive surgical approaches to obtain curative resections could bring about a better prognosis in hilar cholangiocarcinoma independently of whether hepatic resection or local resection is performed.


American Journal of Surgery | 2001

Benefits and limits of hepatic resection for gastric metastases.

Satoshi Ambiru; Masaru Miyazaki; Hiroshi Ito; Koji Nakagawa; Hiroaki Shimizu; Hiroyuki Yoshidome; Yoshiaki Shimizu; Nobuyuki Nakajima

BACKGROUND The significance of hepatic resection for gastric metastases has been controversial. METHODS Forty consecutive patients undergoing hepatic resection for gastric metastases were reviewed to examine the benefits and the limits of hepatic resection using univariate and multivariate analyses. RESULTS The overall survival was 27% at 2 years, 18% at 5 years, and 11% at 10 years. Six patients survived more than 5 years. All of the 6 patients underwent anatomical hepatic resection more extensive than segmentectomy, with sufficient resection margin. There were recurrences in 31 patients, and 94% of the recurrences were in the remaining liver. Univariate analysis showed time of hepatic metastases (P = 0.0078) and resection margin (P = 0.024) as significant prognostic factors. Multivariate analysis indicated that only time of hepatic metastases was an independent prognostic factor that influenced survival. CONCLUSIONS These results suggest that in patients with synchronous metastases we should consider patient selection more strictly, and that in patients with metachronous metastases we should perform anatomical hepatic resection with sufficient resection margin.


American Journal of Surgery | 1999

Aggressive surgical resection for hepatic metastases involving the inferior vena cava

Masaru Miyazaki; Hiroshi Ito; Koji Nakagawa; Satoshi Ambiru; Hiroaki Shimizu; Atsushi Okuno; Yuji Nukui; Hideyuki Yoshitomi; Kimihiko Kusashio; Seiji Furuya; Nobuyuki Nakajima

BACKGROUND The implications of aggressive surgical approaches for hepatic metastases involving the inferior vena cava (IVC) have not been clarified yet. The aim of this study is to assess the preliminary results of aggressive surgical resection for hepatic metastases involving the IVC. METHODS Sixteen patients with hepatic metastases involving the IVC underwent surgical resections with the repair and reconstruction of the IVC: patch repair in 2 and ringed Goretex in 1, primary closure in 13 patients. Hepatic metastases were from colorectal cancer in 14, stomach cancer in 1, and uterine cancer in 1 patient. RESULTS Vascular control utilized for resecting the IVC were total hepatic vascular exclusion in 8, hypothermic isolated hepatic perfusion in 3, and side clamp in 5 patients. The combined IVC resection with hepatectomy in 16 patients brought about 25% and 6% surgical morbidity and mortality rates, respectively. Survival rates following surgical resections were 64%, 33%, 33%, 22%, 22% for 14 patients of colorectal metastases involving the IVC as compared with 82%, 58%, 41%, 37%, 27% at 1, 2, 3, 4, 5 years, respectively, for 154 patients of colorectal metastases not involving the IVC. CONCLUSION Hepatic metastases involving the IVC could be safely resected without an increase in surgical risk. Aggressive surgical approaches might bring about a favorable outcome in select patients with colorectal hepatic metastases involving the IVC.


Journal of Hospital Infection | 2008

Poor postoperative blood glucose control increases surgical site infections after surgery for hepato-biliary-pancreatic cancer: a prospective study in a high-volume institute in Japan

Satoshi Ambiru; Kato A; Fumio Kimura; Hiroaki Shimizu; Hiroyuki Yoshidome; Masayuki Otsuka; Masaru Miyazaki

Two hundred and sixty-five consecutive patients awaiting hepato-biliary-pancreatic surgery were prospectively observed for surgical site infections (SSIs). SSI rates differed according to type of hepato-biliary-pancreatic surgery. Multivariate analysis identified enteric anastomoses, poor postoperative blood glucose control and type of cancer as independent risk factors. SSI rates were directly correlated with the degree of hyperglycaemia encountered during the postoperative period. In particular, SSI rates were 5/25 (20%) among patients in whom a blood glucose level of <200mg/dL was maintained by insulin infusion therapy, which was significantly better than the rates of 49/94 (52%) among patients in whom a blood glucose level of <200mg/dL was not maintained despite insulin infusion therapy (P<0.01). It is necessary to maintain postoperative blood glucose levels of <200mg/dL in order to reduce SSI rates.


Journal of Hepatology | 2000

Obstructive jaundice impairs hepatic sinusoidal endothelial cell function and renders liver susceptible to hepatic ischemia/reperfusion

Hiroyuki Yoshidome; Masaru Miyazaki; Hiroaki Shimizu; Hiroshi Ito; Koji Nakagawa; Satoshi Ambiru; Nobuyuki Nakajima; Michael J. Edwards; Alex B. Lentsch

BACKGROUND/AIMS Obstructive jaundice is associated with increased surgical morbidity and mortality. While parenchymal injury has been defined in obstructive jaundice, the pathogenesis of hepatic sinusoidal endothelial cell injury in obstructive jaundice is unclear. The aims of this study were to investigate hepatic sinusoidal endothelial cell injury in obstructive jaundice by determining serum hyaluronic acid levels, purine nucleoside phosphorylase/alanine aminotransferase ratios, and hyaluronic acid elimination rate, and also to determine whether hepatic parenchymal cell injury in obstructive jaundice is induced more than in normal liver after hepatic ischemia/reperfusion. METHODS Male Wistar rats underwent ligation and division of the common bile duct (obstructive jaundice group) or sham operation (Sham group). Serum hyaluronic acid levels and purine nucleoside phosphorylase/alanine aminotransferase ratios in both groups were examined at intervals up to 21 days after surgery. Hepatic blood flow, permeability, neutrophil accumulation, and hyaluronic acid elimination rates in both groups were measured 14 days after surgery. Changes in serum hyaluronic acid and alanine aminotransferase concentrations were determined after 15 min of hepatic ischemia followed by reperfusion. RESULTS Serum hyaluronic acid levels remained elevated after bile duct ligation. Hepatic sinusoidal endothelial cell swelling was observed by electron microscopy, and hepatic permeability was increased 14 days after bile duct ligation in association with neutrophil accumulation. Hepatic blood flow in obstructive jaundice remained unchanged, but hyaluronic acid elimination capacity was less than that in the Sham group. After hepatic reperfusion, the disappearance rate of serum hyaluronic acid in obstructive jaundice was lower, and serum alanine aminotransferase levels were higher than those in the Sham group. CONCLUSIONS Our findings suggest that obstructive jaundice impairs sinusoidal endothelial cells and that sinusoidal endothelial cell damage in association with sinusoidal deterioration during obstructive jaundice renders liver susceptible to ischemia/reperfusion relative to normal liver.


American Journal of Surgery | 1998

Segments I and IV Resection as a New Approach for Hepatic Hilar Cholangiocarcinoma

Masaru Miyazaki; Hiroshi Ito; Koji Nakagawa; Satoshi Ambiru; Hiroaki Shimizu; Yoshiaki Shimizu; Okuno A; Satoshi Nozawa; Yuji Nukui; Hideyuki Yoshitomi; Nobuyuki Nakajima

Major hepatic resection for biliary tract carcinoma with obstructive jaundice has been reported on as bringing about high surgical morbidity and mortality rates. It has been also revealed that the extent of hepatic resection is closely associated with the occurrence of postoperative complications. Therefore, hepatic resection, limited as much as possible to what is necessary for curative resection, should be performed according to cancer extent. We performed a new surgical approach in 3 patients with hepatic hilar cholangiocarcinoma that included total resection of hepatic segments I and IV (by Couinauds classification) and bile duct resection with hepaticojejunostomy of 4 to 6 intrahepatic bile duct stumps. All patients underwent curative surgical resections and were discharged within 6 weeks after surgery, without any serious complications. This limited resection of hepatic segments I and IV could be an effective radical surgical procedure for hepatic hilar cholangiocarcinoma, to avoid the occurrence of postoperative liver failure.


American Journal of Surgery | 2009

Risk factors of liver dysfunction after extended hepatic resection in biliary tract malignancies

Kosuke Suda; Masayuki Ohtsuka; Satoshi Ambiru; Fumio Kimura; Hiroaki Shimizu; Hiroyuki Yoshidome; Masaru Miyazaki

BACKGROUND Postoperative hepatic insufficiency is a critical complication after extended hepatic resection in patients with biliary tract malignancies, the majority of whom suffer from obstructive jaundice. The aim of this study was to assess clinical parameters linked to this type of liver dysfunction. METHODS A total of 111 patients were retrospectively reviewed. Patient background, pre- and intraoperative parameters, and a ratio of remnant liver volume/entire liver volume (RLV/ELV) as a volumetric parameter were compared between patients with and without postoperative hyperbilirubinemia and subsequent fatal outcome. RESULTS Logistic regression indicated that only RLV/ELV ratio was an independent factor influencing postoperative hyperbilirubinemia, and RLV/ELV ratio and indocyanine green retention rate at 15 minutes (ICG-R15) were factors affecting survival. Patients with RLV/ELV less than 40% had 7.6 times the risk of postoperative hyperbilirubinemia, while no patients with RLV/ELV greater than 40% and ICG-R15 less than 25% died of liver failure. CONCLUSIONS The RLV/ELV ratio was the factor with the greatest impact on liver dysfunction after extended hepatectomy in patients with biliary tract malignancies.


Pancreas | 2006

Increased plasma levels of IL-6 and IL-8 are associated with surgical site infection after pancreaticoduodenectomy.

Fumio Kimura; Hiroaki Shimizu; Hiroyuki Yoshidome; Masayuki Ohtsuka; Atsushi Kato; Hideyuki Yoshitomi; Satoshi Nozawa; Katsunori Furukawa; Noboru Mitsuhashi; Shigeaki Sawada; Dan Takeuchi; Satoshi Ambiru; Masaru Miyazaki

Objectives: Cytokines and chemokines potentially modulate postoperative immune response. Association of circulating cytokines and chemokines with postoperative infectious complications after pancreaticoduodenectomy was evaluated. Methods: Plasma concentrations of interleukin (IL) 6, IL-10, IL-8, macrophage chemoattractant protein 1, heat shock protein 70, and amylase, as well as amylase levels in peritoneal exudative fluid, were measured perioperatively in 60 consecutive patients who underwent pancreaticoduodenectomy. Results: Of the 60 patients, 27 patients had surgical site infection (SSI), including peritoneal infection in all, intra-abdominal abscess in 14, and radiologically visualized pancreatic leakage in 6. Postoperative plasma levels of IL-6, IL-8, and macrophage chemoattractant protein 1, as well as peritoneal amylase levels, were significantly higher in patients with SSI than in those without SSI (P < 0.05). Nonpancreatic cancer as a histopathologic diagnosis, high pancreatic juice flow, and increased levels of IL-6 and IL-8 were independently associated with SSI (P < 0.05) in multiple logistic regression analysis. Plasma levels of IL-6 and IL-10 among patients with SSI were significantly higher in those with pancreatic leakage than in those without leakage. Conclusions: These results suggest that, in addition to pancreatic exocrine function, IL-6 and IL-8 are associated with postoperative SSI, including pancreatic leakage after pancreaticoduodenectomy.


Journal of Gastroenterology and Hepatology | 1999

Effective hepatic artery chemoembolization for advanced hepatocellular carcinoma with extensive tumour thrombus through the hepatic vein

Yasushige Kashima; Masaru Miyazaki; Hiroshi Ito; Takashi Kaiho; Koji Nakagawa; Satoshi Ambiru; Hiroaki Shimizu; Seiji Furuya; Nobuyuki Nakajima

Background and Aims : Advanced hepatocellular carcinoma (HCC) with extensive tumour growth through the hepatic vein still has an extremely poor prognosis, even after cancer chemotherapy and/or transarterial embolization. Although aggressive surgical treatments using extracorporeal circulation and liver transplantation have been performed by some authors, the reported results were still unsatisfactory. In this study, we report the favourable result of hepatic artery chemoembolization and subsequent surgical resection in three patients with advanced HCC with extensive tumour thrombus through the hepatic vein.

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Hiroshi Ito

Fukushima Medical University

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