Izumi Muraoka
Nagasaki University
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Featured researches published by Izumi Muraoka.
British Journal of Surgery | 2012
Masaaki Hidaka; Mitsuhisa Takatsuki; Akihiko Soyama; Takayuki Tanaka; Izumi Muraoka; Takanobu Hara; Tamotsu Kuroki; Takashi Kanematsu; Susumu Eguchi
Outcomes of liver resection for hepatocellular carcinoma (HCC) have improved owing to better surgical techniques and patient selection. Portal hypertension may influence outcome but the preoperative definition and role of portal hypertension are far from clear. The aim of this study was to elucidate the influence of portal venous pressure (PVP) measured directly during surgery on outcomes of liver resection in patients with HCC.
Transplantation proceedings | 2012
Akihiko Soyama; Mitsuhisa Takatsuki; Masaaki Hidaka; Izumi Muraoka; Takayuki Tanaka; Izumi Yamaguchi; Ayaka Kinoshita; Takanobu Hara; Susumu Eguchi
BACKGROUND Recently, applications of less invasive liver surgery in living donor hepatectomy (LDH) have been reported. The objective of this study was to evaluate the safety and efficacy of a hybrid method with a midline incision for LDH. METHODS Hemihepatectomy using the hybrid method was performed in the fifteen most recent among 150 living donors who underwent surgery between 1997 and August 2011. Six donors underwent right hemihepatectomy and 9 underwent left hemihepatectomy. An 8-cm subxiphoid midline incision was created for hand assistance during liver mobilization and graft extraction. After sufficient mobilization of the liver, the hand-assist/extraction incision was extended to 12 cm for the right hemihepatectomy and 10 cm for a left hemihepatectomy. Encircling the hepatic veins and hilar dissection were performed under direct vision. Parenchymal transection was performed with the liver hanging maneuver. Bile duct division was performed after visualizing the planned transection point by encircling the bile duct using a radiopaque marker filament under real-time C-arm cholangiography. RESULTS All procedures were completed without any extra subcostal incision. All grafts were safely extracted through the 10-12-cm upper midline incision without mechanical injury. No donors required an allogeneic transfusion; all of them have returned to their preoperative activity levels. CONCLUSION LDH by the hybrid method with a short upper midline incision is a safe procedure.
Surgery | 2011
Susumu Eguchi; Mitsuhisa Takatsuki; Akihiko Soyama; Masaaki Hidaka; Tetsuo Tomonaga; Izumi Muraoka; Takashi Kanematsu
BACKGROUND Although the technique of liver transplantation is well developed, the invasiveness of the operation can be decreased with laparoscopic procedures. METHODS We performed elective living donor liver transplantation (LDLT) through a short midline incision combined with hand-assisted laparoscopic surgery (HALS). Nine selected patients with end stage liver disease underwent the procedure between July, 2010 and February, 2011 (median age 60, median Child-Pugh 9, median MELD score 14). Splenectomy was performed simultaneously in 7 cases. The liver (and spleen) were mobilized by a sealing device under a HALS procedure with an 8-cm upper midline incision, followed by explantation of the diseased liver (and spleen) through the upper midline incision which was extended to 12 to 15 cm. Partial liver grafts were implanted through the upper midline incision. RESULTS The median duration of the operation was 741 minutes, the median time needed for anastomosis was 48 minutes, the median blood loss was 3,940 g, and the median liver weight was 866 g. Eight recipients are alive and have good graft function. A difficult implantation for one patient required an additional right transverse incision. When compared with 13 recent liver recipients who underwent LDLT with a regular Mercedes-Benz-type incision, no clinically relevant drawbacks of the HALS hybrid procedure were observed. CONCLUSION We have shown the feasibility and safety of LDLT performed through a short midline incision without abdominal muscle disruption with the aid of HALS.
Clinical Transplantation | 2012
Yusuke Inoue; Akihiko Soyama; Mitsuhisa Takatsuki; Masaaki Hidaka; Izumi Muraoka; Takashi Kanematsu; Susumu Eguchi
Although acute kidney injury (AKI) is regarded as a frequent complication following deceased donor liver transplantation, the incidence of AKI following living donor partial liver transplantation (LDLT) has not yet been sufficiently investigated.
Surgery Today | 2011
Susumu Eguchi; Akihiko Soyama; Masaaki Hidaka; Mitsuhisa Takatsuki; Izumi Muraoka; Tetsuo Tomonaga; Takashi Kanematsu
Liver transplantation for patients with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) remains challenging. The advent of highly active antiretroviral therapy (HAART) for HIV has reduced mortality from opportunistic infection related to acquired immunodeficiency syndrome dramatically, while about 50% of patients die of end-stage liver cirrhosis resulting from HCV. In Japan, liver cirrhosis frequently develops after HCV-HIV coinfection resulting from previously transfused infected blood products for hemophilia. The problems of liver transplantation for those patients arise from the need to control calcineurin inhibitor with HAART drugs, the difficulty of using interferon after liver transplantation with HAART, and the need to control intraoperative coagulopathy associated with hemophilia. We review published reports of liver transplantation for these patients in the updated world literature.
Clinical Transplantation | 2013
Hajime Imamura; Akihiko Soyama; Mitsuhisa Takatsuki; Izumi Muraoka; Takanobu Hara; Izumi Yamaguchi; Takayuki Tanaka; Ayaka Kinoshita; Tamotsu Kuroki; Susumu Eguchi
The application of less invasive techniques for liver surgery in patients undergoing living donor hepatectomy (LDH) has been reported. The objective of this study was to evaluate physical status according to type of incision in donors.
Hepato-gastroenterology | 2011
Izumi Muraoka; Akihiko Soyama; Mitsuhisa Takatsuki; Tetsuo Tomonaga; Masaaki Hidaka; Takashi Kanematsu; Susumu Eguchi
BACKGROUND/AIMS Serum alkaline phosphatase (ALP) levels tend to increase after hepatectomy, however, no previous examinations have yet focused on the relationship between liver regeneration and the individual ALP isoenzymes levels. METHODOLOGY Forty living liver transplantation donors who underwent hemi-hepatectomy were herein investigated. We evaluated the serum ALP levels and ALP isoenzyme levels preoperatively and postoperatively. The liver regeneration rate (LRR) was calculated using volumetry. According to the LRR, we divided the donors into two groups, consisting of a high regeneration group (HG) and a low regeneration group (LG). RESULTS The total serum ALP levels increased gradually after hepatectomy and peaked on postoperative days (POD) 14. ALP-1 was not detected in any donor preoperatively; however it was detected after hepatectomy, peaking on POD 7. The serum ALP-2 level increased after hepatectomy, reaching a peak level on POD 14. The ALP-2 levels gradually increased after hepatectomy and reached peak levels on POD 14 in both groups. However, the ALP-2 level on POD 14 was significantly higher in HG than LG. CONCLUSIONS The serum ALP- 2 levels after POD 14 might therefore be a useful indicator of favorable liver regeneration following hepatectomy, especially in patients who have a normal liver function.BACKGROUND/AIMS Serum alkaline phosphatase (ALP) levels tend to increase after hepatectomy. However, no previous examinations have yet focused on the relationship between liver regeneration and the individual ALP isoenzymes levels. METHODOLOGY Forty living liver transplantation donors who underwent hemi-hepatectomy were herein investigated. We evaluated the serum ALP levels and ALP isoenzyme levels preoperatively and postoperatively. The liver regeneration rate (LRR) was calculated using volumetry. According to the LRR, we divided the donors into two groups, consisting of a high regeneration group (HG) and a low regeneration group (LG). RESULTS The total serum ALP levels increased gradually after hepatectomy and peaked on postoperative day (POD) 14. ALP-1 was not detected in any donor preoperatively. However, it was detected after hepatectomy, peaking on POD 7. The serum ALP-2 level increased after hepatectomy, reaching a peak level on POD 14. The ALP-2 levels gradually increased after hepatectomy and reached peak levels on POD 14 in both groups. However, the ALP-2 level on POD 14 was significantly higher in HG than LG. CONCLUSIONS The serum ALP-2 levels after POD 14 might therefore be a useful indicator of favorable liver regeneration following hepatectomy, especially in patients who have a normal liver function.
Journal of Hepato-biliary-pancreatic Sciences | 2014
Takayuki Tanaka; Mitsuhisa Takatsuki; Masaaki Hidaka; Takanobu Hara; Izumi Muraoka; Akihiko Soyama; Tomohiko Adachi; Tamotsu Kuroki; Susumu Eguchi
Although several reports have shown the efficacy of a fluorescence navigation system (FNS) with indocyanine green (ICG) to detect liver malignancies during hepatectomy, the real accuracy of this procedure is not yet clear. This study aimed to analyze the actual efficacy of ICG‐FNS in cirrhotic and non‐cirrhotic livers.
Journal of Tissue Engineering and Regenerative Medicine | 2015
Izumi Muraoka; Mitsuhisa Takatsuki; Yusuke Sakai; Tetsuo Tomonaga; Akihiko Soyama; Masaaki Hidaka; Yoshitaka Hishikawa; Takehiko Koji; Rie Utoh; Kazuo Ohashi; Teruo Okano; Takashi Kanematsu; Susumu Eguchi
Cell sheet engineering has been noted as a new and valuable approach in the tissue‐engineering field. The objective of this study was to explore a procedure to induce hepatic progenitor cells and biliary duct structures in the liver. Sprague–Dawley rat dermal fibroblast (DF) sheets were transplanted into the incised surface of the liver of F344 nude rats. In the control group, an incision was made without transplantation of the DF sheets. Bile duct (BD)‐like structures and immature hepatocyte‐like cells were observed in the DF sheet transplant sites. These BD‐like structures were cytokeratin‐8‐positive, while the hepatocyte‐like cells were both OV‐6‐positive and α‐fetoprotein‐positive as well. The proliferation and differentiation of liver progenitor cells were not influenced by hepatectomy. We also transplanted DF sheets transfected with a plasmid encoding the enhanced yellow fluorescent protein target to mitochondria (pEYFP–Mito) by electroporation, and found that the new structures were pEYFP–Mito‐negative. We observed new BD‐like structures and immature hepatocytes after transplantation of DF sheets onto incised liver surfaces, and clarified that the origin of these BD‐like structures and hepatocyte‐like cells was the recipient liver. The present study described an aspect of the hepatic differentiation process induced at the site of liver injury. Copyright
Hepato-gastroenterology | 2011
Tetsuo Tomonaga; Susumu Eguchi; Masaaki Hidaka; Mitsuhisa Takatsuki; Akihiko Soyama; Izumi Muraoka; Akimasa Mizutani; Hiroshi Fukui; Takashi Kanematsu
This article reports a patient with intra-abdominal hemorrhage secondary to a rare vascular disease, segmental arterial mediolysis (SAM). The patient was a 68-year-old male who presented with chilling and severe abdominal pain. Abdominal computed tomography results suggested the presence of an intra-abdominal hemorrhage. Although visceral angiography illustrated multiple aneurysms in the branches of the hepatic artery, active bleeding was not evident. Conservative therapy including transfusion was performed, and re-angiography revealed the disappearance of multiple hepatic arterial aneurysms 8 months later. This is the first case of intra-abdominal hemorrhage related to SAM of the hepatic artery in which natural history of SAM was seen.