Tatsuya Okamoto

Nagasaki University, Nagasaki-shi, Nagasaki-ken, Japan

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Publications (10)7.73 Total impact

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    ABSTRACT: Although laparoscopic pancreatic resections have become more common, laparoscopic minimally invasive and function-preserving pancreatic resections have not been widely accepted. Branch-type intraductal papillary mucinous neoplasm (IPMN) has a low-grade malignant potential and shows a favorable prognosis. In branch-type IPMN, minimal resection techniques with preservation of the pancreatic functional reserve have advantages over the more conventional pancreaticoduodenectomy. We describe herein laparoscopic single-branch resection of the pancreas for branchtype IPMN. This surgical procedure is a novel and an ideal minimally invasive method for the resection of branch-type IPMN. In addition, our endoscopic nasopancreatic drainage (ENPD) tube-guided technique is useful for precise resection of the tumor and for the prevention of pancreatic fistula.
    Hepato-gastroenterology 01/2012; 59(116):997-9. · 0.77 Impact Factor
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    ABSTRACT: It is well known that to achieve insulin independence requires a high number of islets, but at present, isolation techniques can recover 50% or less of the islets present in the pancreas. Brain death is characterized by a cytokine storm that takes place in the body, and this condition reduces the islet yields and functions. In this study, we used selective neutrophil elastase inhibitor, sivelestat sodium to prevent damage to the islets for transplantation. We used three groups of rats, group 1 were transfused with only saline, group 2 received sivelestat sodium (10 mg/kg/h) and group 3 received a higher dose of sivelestat sodium (30 mg/kg/h). Thirty minutes after the treatment, lipopolysaccharide was injected to induce hypercytokinemia. We examined serum cytokine levels, derivatives of reactive oxygen metabolites (d-ROMs), islet yields and viability and 24 hours after static incubation, the islet yields, viability, functions (insulin stimulation index and ADP/ATP ratio). The levels of serum cytokines, IL-1β, IL-6 and IFN-γ were significantly different between groups 1 and 3. The islet yields and the 24 h recovery rate of islets and insulin stimulation index were significantly higher in group 3 compared with group 1. The d-ROMs and ADP/ATP ratio were decreased by dose dependently in group 2 and 3. The islet yields and functions in vitro were significantly improved by the treatment with sivelestat sodium. These experiments may lead to marginal donors, pre-treated with sivelestat sodium becoming acceptable for islet transplantation.
    Annals of transplantation: quarterly of the Polish Transplantation Society 12/2011; 16(4):99-106. · 0.82 Impact Factor
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    ABSTRACT: Zinc (Zn) is related to insulin synthesis, storage and secretion. Zn status in patients with Type 1 diabetes is significantly lower than in healthy controls. Intraportal islet transplantation (IPIT) is a radical treatment for diabetes, the success of which depends largely on the survival of the transplanted islets. This study demonstrates the impact of a Zn-rich environment on transplanted islet survival. Diabetic Wistar rats were transplanted with syngeneic islets. Rats in the high-Zn-diet group were fed a standard pelleted diet containing ZnSO4 at 1000 ppm, whereas those in the control group were fed an ordinary diet alone (ZnSO4 at 50 ppm) for two weeks prior to islet transplantation. We examined Zn level of plasma, the blood glucose levels, and histological findings, etc., after intraportal islet transplantation. The high-Zn-diet group showed excellent blood glucose control compared with the control group on observation days 3, (237.1±120.6 mg/dl vs. 164.2±69.1 mg/dl; p<0.05) and 14, (273.7±160.9 mg/dl vs. 179.2±114.3 mg/dl; p<0.05). Early graft failure was found to be suppressed in the high-Zn-diet group on day 3 after transplantation (6.7% vs. 33.3%: p<0.05). As for the percentage of granulated islets, the high-Zn-diet group was improved (65.1% vs. 41.8%: p<0.05). These results indicated that a zinc-rich environment is advantageous for the recipient in intraportal islet transplantation. Zn is harmless in humans; thus, we consider that Zn supplementation could be a simple way to improve clinical results of intraportal islet transplantation.
    Annals of transplantation: quarterly of the Polish Transplantation Society 09/2011; 16(3):114-20. · 0.82 Impact Factor
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    ABSTRACT: Background/Aims: Laparoscopic surgery for periampullary disease is still a challenging operation. The aim of this study was to compare the perioperative outcomes of patients undergoing conventional pancreaticoduodenectomy (PD) with the outcomes of those undergoing laparoscopy-assisted PD. Methodology: A retrospective analysis was conducted on 51 consecutive patients who underwent laparoscopy-assisted or open PD for periampullary disease. Results: There were no significant differences in the preoperative demographic or clinical data of the two study groups. Although there were no significant differences in the operative time between the two study groups, blood loss in the laparoscopy-assisted PD group was significantly smaller than that in the open PD group. There were no significant differences in the occurrence of postoperative complications between the two groups. Conclusions: Laparoscopy-assisted PD is a feasible and safe surgical procedure that provides the advantages expected from a minimally invasive surgery including less blood loss.
    Hepato-gastroenterology 08/2011; 59(114):570-3. · 0.77 Impact Factor
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    ABSTRACT: Single-incision laparoscopic surgery (SILS) is a novel area of minimally invasive surgery, and rapidly evolving in the field of abdominal surgery. However, SILS is not a common procedure for pancreatic surgery. We describe our first experience with a SILS approach in a patient with a metastatic pancreatic tumor. We performed a SILS distal pancreatectomy (SILS-DP) using 3 trocars placed through a single port at an umbilical incision. In our case, the most important surgical technique was the stomach-hanging method to obtain a favorable laparoscopic view of the pancreas. Although SILS-DP is a safe and feasible procedure, further studies are required to determine the advantages of this procedure in comparison with the standard laparoscopic method.
    Hepato-gastroenterology 01/2011; 58(107-108):1022-4. · 0.77 Impact Factor
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    ABSTRACT: Single-incision laparoscopic cholecystectomy (SILC) has rapidly spread throughout the world because of its low invasiveness and because it is a scarless procedure. Various surgical methods of performing SILC are present in each institute; however, it is necessary to develop a standardized procedure that we can perform safely, such as the conventional 4-port laparoscopic cholecystectomy (LC). The SILC experiment in our institute was started by use of the commercial SILS Port and changed from a 3-port method via an umbilicus to a 2-port method to improve some problems. Although none of the conversions to conventional 4-port LC and also none of the complications such as bile duct injury occurred in each method, the 2-port method functioned best and was also economical. However, it is most important to adopt strict criteria and select the patients suitable for SILC to demonstrate SILC safety same as 4-port LC.
    Minimally invasive surgery. 01/2011; 2011:972647.
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    ABSTRACT: Laparoscopic cholecystectomy is difficult to perform in patients with a low-lying costal arch that entirely covers the liver. We conducted this study to clarify the factors related to a low-lying costal arch and establish countermeasures to circumvent this characteristic. The study included 103 consecutive patients who underwent a laparoscopic cholecystectomy. The possible clinical factors associated with a low-lying costal arch restricting the operative working space were analyzed. The position of the liver against the costal arch and the presumed surgical visual angle for laparoscopic cholecystectomy, comprising the hepatic porta, umbilicus, and costal arch, were estimated with abdominal multidetector computed tomography (MDCT). Seven (7%) patients had a low-lying costal arch presenting an inadequate exposure of Calot's triangle and restricted instrument mobility during laparoscopic cholecystectomy, and three patients required conversion to a laparotomy. A low-lying costal arch was significantly associated with advanced age, shorter stature, lighter body weight, coexisting kyphoscoliosis, gallbladder pathology, laparotomy conversion, and most of all, the liver edge lying above the costal arch and a narrow surgical visual angle upon MDCT. Of the seven patients with a critical low-lying costal arch, four underwent a successful laparoscopic cholecystectomy, this being done by lifting the right costal arch to create a workable surgical field; the rib-lifting procedure was planned as part of the scheduled procedure in the other three patients because the preoperative MDCT examination indicated a poor working space for a laparoscopic cholecystectomy. A low-lying costal arch is a substantial risk factor for conversion to a laparotomy when performing a laparoscopic cholecystectomy. However, the operative difficulty related to a low-lying costal arch can be predicted by using preoperative MDCT images and can be managed with proper planning and the appropriate use of the rib-lifting technique.
    Journal of hepato-biliary-pancreatic sciences. 01/2011; 18(1):60-6.
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    ABSTRACT: Single-incision laparoscopic cholecystectomy (SILC) has recently become a topic of interest among types of minimally invasive surgery. We developed a novel "marionette method"technique for performing SILC. Two 5 mm trocars were placed through a 1.5 cm transumbilical incision. In addition, a nylon suture with a laparoscopic sliding knot was used to tighten the fundus of the gallbladder and was thereafter suspended with this nylon suture. The neck of the gallbladder was tightened by means of a loop type retractor, to enable adequate visualization of the triangle of Calot. Dissection was performed as a conventional laparoscopic cholecystectomy using standard straight laparoscopic instruments. All 20 patients successfully underwent a single-incision, two-trocar laparoscopic cholecystectomy performed using the marionette method. The mean operative time was 119 min. There were no complications. The marionette method can provide good tension and an appropriate laparoscopic view with a suitable surgical field for safely performing a dissection at the triangle of Calot during SILC.
    Hepato-gastroenterology 01/2011; 58(107-108):729-31. · 0.77 Impact Factor
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    ABSTRACT: Laparoscopic common bile duct exploration (LCBDE) is one of the standard surgical procedures for treating choledocholithiasis. Several methods of biliary drainage following LCBDE have been advocated to prevent bile leakage. We report herein a surgical procedure using a plastic biliary stent tube following LCBDE for biliary drainage. Our method is technically simple, feasible and an ideal procedure for biliary drainage with LCBDE.
    Hepato-gastroenterology 01/2010; 57(102-103):1034-6. · 0.77 Impact Factor
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    ABSTRACT: The anatomical status of the pancreatic remnant after a pancreatic head resection varies greatly among patients. The aim of the present study was to improve management of the pancreatic remnant for reducing pancreatic fistula after pancreatic head resection. Ninety-five consecutive patients who underwent an end-to-side, duct-to-mucosa pancreaticojejunostomy after pancreatic head resection were included in the study. To approximate the pancreatic stump to the jejunum, the transfixing and interrupted suture techniques were used in 51 and 44 patients, respectively. We modified the interrupted suture technique according to the anatomical status of the pancreatic remnant, i.e., the shape of the pancreatic stump and the location of the pancreatic duct. There was no operative mortality in this study. Overall, 14 patients (15%) developed a clinically relevant pancreatic fistula. Certain anatomical features, including a small pancreatic duct, a soft, nonfibrotic pancreatic gland, and a pancreatic duct adjacent to the posterior cut edge, were significantly associated with pancreatic fistula. The fistula rate in the interrupted suture group was 7%, lower than that (22%) in the transfixing suture group (P = 0.036), and it was not influenced by pancreatic anatomy. Multivariate analysis identified a nonfibrotic pancreas (versus fibrotic pancreas; odds ratio [OR] 12.58, 95% CI 1.2-23.9; P = 0.001), a soft pancreas (versus hard pancreas; OR 4.67, CI 1.2-51.1; P = 0.006), and the transfixing suture technique (versus interrupted suture technique; OR 9.91, CI 1.7-57.5; P = 0.003) as significant predictors of clinically relevant pancreatic fistula. Pancreatic anastomosis modified according to the pancreatic anatomy is effective in reducing the risk of pancreatic fistula formation with end-to-side, duct-to-mucosa pancreaticojejunostomy after pancreatic head resection.
    World Journal of Surgery 09/2009; 33(10):2166-76. · 2.23 Impact Factor