Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Yoshiyasu Ambo is active.

Publication


Featured researches published by Yoshiyasu Ambo.


Annals of Surgery | 2004

Forty Consecutive Resections of Hilar Cholangiocarcinoma With No Postoperative Mortality and No Positive Ductal Margins: Results of a Prospective Study

Satoshi Kondo; Satoshi Hirano; Yoshiyasu Ambo; Eiichi Tanaka; Shunichi Okushiba; Toshiaki Morikawa; Hiroyuki Katoh

Objective:Our objective was to perform a prospective study of surgical treatment of hilar cholangiocarcinoma according to newly established guidelines for performing safe and curative resections. Summary Background Data:The poor survival rate after resection of hilar cholangiocarcinoma is considered to be mainly the result of in-hospital death and positive ductal margins. Methods:Between July 1999 and December 2002, 40 of 42 surgically explored patients with hilar cholangiocarcinoma underwent resection. They were managed with preoperative biliary decompression, portal embolization, cholangiographic evaluation, and a choice of surgical procedures and techniques. Results:Hospital or 30-day mortality and morbidity rates were 0% and 48%, respectively. Hepatic failure was not encountered. Histopathologic examination revealed no positive ductal margins in all 40 patients, but 2 showed positive separation margins from the right hepatic artery. The overall 3-year survival rate and median survival time were 40% and 27 months. Survival of patients with Bismuth type III or IV tumors or of patients who underwent right hepatectomy was significantly better. Survival of patients who underwent concomitant vascular resection was similar to survival of those who did not. Univariate analysis indicated the type of hepatectomy, histopathologic grade, Bismuth classification, concomitant hepatic artery resection, and International Union Against Cancer stage as significant prognostic factors. Conclusions:No postoperative mortality and no positive ductal margins were achieved according to the above guidelines in a high-volume expert center. Long-term results, however, have not been significantly improved. A survival analysis of the patient series with homogeneous conditions derived from a short study period suggests the need for additional strategies including right hepatectomy for Bismuth type I or II tumors.


Annals of Surgery | 2007

Distal Pancreatectomy With En Bloc Celiac Axis Resection for Locally Advanced Pancreatic Body Cancer: Long-term Results

Satoshi Hirano; Satoshi Kondo; Takashi Hara; Yoshiyasu Ambo; Eiichi Tanaka; Toshiaki Shichinohe; On Suzuki; Kazuaki Hazama

Objective:To analyze the long-term results of distal pancreatectomy with en bloc celiac axis resection (DP-CAR), a newly designed extended surgical procedure for locally advanced cancer of the pancreatic body. Summary Background Data:Pancreatic body cancer often involves the common hepatic artery and/or the celiac axis and is regarded as an unresectable disease. We previously reported the feasibility and safety of DP-CAR in 10 patients and 3 preliminary cases; however, the long-term results are unknown. Methods:Between May 1998 and September 2005, 23 patients underwent DP-CAR. No reconstruction of the arterial system was required because of early development of the collateral arterial pathways via the pancreatoduodenal arcades from the superior mesenteric artery. We routinely used preoperative coil embolization of the common hepatic artery to enlarge the collateral pathways. Results:The postoperative mortality rate was 0%, despite a high morbidity rate (48%). The chief postoperative complications were pancreatic fistula and ischemic gastropathy. Contrary to expectations, postoperative diarrhea was mild. Preoperative intractable abdominal and/or back pain in 10 patients was completely alleviated immediately after surgery. The surgical margins were histologically negative in 21 patients (91%). The estimated overall 1- and 5-year survival rates were 71% and 42%, respectively, and the median survival was 21.0 months. The sites of recurrence were the liver in 6 patients and local recurrence in 2. Conclusions:DP-CAR offers a high R0 resectability rate and may potentially achieve complete local control in selected patients. The persisting early hepatic recurrence may indicate DP-CAR for the treatment of less advanced disease.


Surgery | 2013

Triclosan-coated sutures reduce the incidence of wound infections and the costs after colorectal surgery: A randomized controlled trial

Toru Nakamura; Nobuichi Kashimura; Takehiro Noji; On Suzuki; Yoshiyasu Ambo; Fumitaka Nakamura; Akihiro Kishida

BACKGROUND In colorectal surgeries, surgical site infections (SSIs) frequently cause morbidity; an incidence of up to 20% has been shown in previous studies. Recently, to prevent microbial colonization of suture material in operative wounds, triclosan-coated polyglactin suture materials with antimicrobial activity have been developed; however, their significance in colorectal surgery remains unclear. This randomized controlled trial was conducted to assess the value of triclosan-coated polyglactin sutures in colorectal surgery. METHODS A total of 410 consecutive patients who had undergone elective colorectal operations were enrolled in this trial. Of those patients, the 206 in the study group underwent wound closure with triclosan-coated polyglactin 910 antimicrobial sutures, and the 204 patients in the control group received conventional wound closures with polyglactin 910 sutures. RESULTS The study group and the control group were comparable regarding risk factors for SSIs. The incidence of wound infection in the study group was 9 of 206 patients (4.3%), and that in the control group was 19 of 204 patients (9.3%). The difference is statistically significant in the 2 groups (P = .047). The median additional cost of wound infection management was


British Journal of Surgery | 2003

Portal vein resection and reconstruction prior to hepatic dissection during right hepatectomy and caudate lobectomy for hepatobiliary cancer

Satoshi Kondo; Hiroyuki Katoh; Satoshi Hirano; Yoshiyasu Ambo; E. Tanaka; Syunichi Okushiba

2,310. The actual entire additional cost, therefore, of 9 patients in the study group was


British Journal of Surgery | 2004

Arterioportal shunting as an alternative to microvascular reconstruction after hepatic artery resection

Satoshi Kondo; Satoshi Hirano; Yoshiyasu Ambo; E. Tanaka; T. Kubota; Hiroyuki Katoh

18,370, and that of 19 patients in the control group was


Surgery Today | 2004

Ischemic gastropathy after distal pancreatectomy with celiac axis resection.

Satoshi Kondo; Hiroyuki Katoh; Satoshi Hirano; Yoshiyasu Ambo; Eiichi Tanaka; Yoshihiro Maeyama; Toshiaki Morikawa; Shunichi Okushiba

60,814. CONCLUSION Triclosan-coated sutures can reduce the incidence of wound infections and the costs in colorectal surgery.


Surgery Today | 2001

Portal Venous Dilatation and Stenting for Bleeding Jejunal Varices: Report of Two Cases

Kei Hiraoka; Satoshi Kondo; Yoshiyasu Ambo; Satoshi Hirano; Makoto Omi; Shunichi Okushiba; Hiroyuki Katoh

Hepatobiliary cancer invading the hilar bile duct often involves the portal bifurcation. Portal vein resection and reconstruction is usually performed after completion of the hepatectomy. This retrospective study assessed the safety and usefulness of portal vein reconstruction prior to hepatic dissection in right hepatectomy and caudate lobectomy plus biliary reconstruction, one of the common procedures for radical resection.


Journal of Gastroenterology | 2005

CT evaluation of paraaortic lymph node metastasis in patients with biliary cancer

Takehiro Noji; Satoshi Kondo; Satoshi Hirano; Eiichi Tanaka; Yoshiyasu Ambo; Yo Kawarada; Toshiaki Morikawa

Portal vein and hepatic artery resection and reconstruction may be required in radical surgery for biliary cancer. Microvascular reconstruction requires special equipment and training, and may be difficult to accomplish when the arterial stump is small, when there are multiple vessels or when the stump lies deep within the wound. This study examined the feasibility and safety of arterioportal shunting as an alternative to arterial reconstruction.


Digestive Surgery | 2004

Outcome of Duodenum-Preserving Resection of the Head of the Pancreas for Intraductal Papillary-Mucinous Neoplasm

Satoshi Hirano; Satoshi Kondo; Yoshiyasu Ambo; Eiichi Tanaka; Toshiaki Morikawa; Shunichi Okushiba; Hiroyuki Katoh

PurposeStomach-preserving distal pancreatectomy with en bloc resection of the celiac, common hepatic, and left gastric arteries is a radical operation performed for locally advanced cancer of the pancreatic body. However, it is not known whether the collateral pathways that develop immediately from the superior mesenteric artery to the gastroduodenal and hepatic arteries provide sufficient blood flow to support the hepatobiliary system and the stomach. This article examines the ischemic gastropathy that can occur after this procedure and identifies the predisposing conditions.MethodsBetween 1997 and 2001, nine patients underwent stomach-preserving distal pancreatectomy with en bloc resection of the celiac, common hepatic, and left gastric arteries. Concomitant resection of the right gastric artery or gastroduodenal artery was performed due to cancer infiltration in three patients.ResultsIrregular, shallow, and wide ulcerations thought to be ischemic in origin developed in these three patients, but all the ulcerations healed in 1–2 weeks with antiulcer medication. None of the other six patients had evidence of gastric ischemia.ConclusionsIschemic gastropathy is rare after distal pancreatectomy with celiac axis resection alone; however, division of additional arteries supplying the stomach may predispose to ischemic gastropathy.


International Journal of Gastrointestinal Cancer | 2005

Superficially spreading cholangiocarcinoma.

Motoki Abe; Satoshi Kondo; Satoshi Hirano; Yoshiyasu Ambo; Eiichi Tanaka; Katsunori Saito; Toshiaki Morikawa; Shunichi Okushiba; Hiroyuki Katoh

Abstract We present two patients who underwent a portal stent placement for bleeding jejunal varices of the afferent loop caused by extrahepatic portal venous stenosis. Case 1 involved a 66-year-old woman who developed bleeding jejunal varices due to extrahepatic portal venous stenosis 1 year after a pancreaticoduodenectomy with intraoperative radiation therapy. Percutaneous transhepatic balloon dilatation and stent placement were performed. Since undergoing the procedure, no bleeding has occurred. Case 2 concerned a 44-year-old woman who had a rupture and bleeding of jejunal varices 16 years after a choledocojejunostomy. Stenosis was observed from the right and left branches of the portal vein to its intrahepatic branches. Both balloon dilatation and stent placement were attempted. However, the stent could not be fully inserted into the intrahepatic portal vein. Portal stent placement is less invasive and radical, and therefore should be attempted for the treatment of extrahepatic portal venous stenosis. However, there are limits to its application if the stenosis extends to the intrahepatic branches of the portal vein.

Collaboration


Dive into the Yoshiyasu Ambo's collaboration.

Top Co-Authors

Avatar

Satoshi Hirano

Nagoya Institute of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Toshiaki Morikawa

Jikei University School of Medicine

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge