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Dive into the research topics where Hiroaki Shigoka is active.

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Featured researches published by Hiroaki Shigoka.


Gastrointestinal Endoscopy | 2009

Metallic stents for gastric outlet obstruction: reintervention rate is lower with uncovered versus covered stents, despite similar outcomes

Iruru Maetani; Takeo Ukita; Tomoko Tada; Hiroaki Shigoka; Shigefumi Omuta; Takuro Endo

BACKGROUND Self-expandable metallic stents (SEMSs) are widely used for palliation of malignant gastric outlet obstruction (GOO). A common complication of their use, however, is stent obstruction caused by tumor ingrowth or hyperplasia. The covered SEMS was designed to prevent these problems. OBJECTIVE We compared the performance of uncovered and covered SEMSs in patients with GOO. DESIGN A retrospective study, single center. SETTING A tertiary-referral center. PATIENTS Sixty patients with symptomatic malignant GOO. INTERVENTIONS All patients received an uncovered or covered knitted nitinol stent by using the over-the-wire placement procedure. MAIN OUTCOME MEASUREMENT Comparison of the clinical outcome, complications, and the reintervention rate between uncovered and covered stents. RESULTS Thirty-one patients (mean [+/-SEM] age 72.2 +/- 2.1 years; 16 men) received uncovered SEMSs, and 29 (mean [+/-SEM] age 70.6 +/- 1.7 years; 17 men) received covered SEMSs. The technical success rate was 100% in both groups. No difference in clinical success was seen (90.3% uncovered group vs 86.2% covered group). Regarding early complications (<1 week), one mild case of pancreatitis from the stent covering the papilla occurred in each group. Late complications included reobstruction, migration, bleeding, stent fracture, and perforation. The occurrence of reobstruction did not differ between the 2 groups (3.2% uncovered group vs 10.3% covered group). No difference in migration (0% uncovered group vs 6.9% covered group) was seen. The uncovered group required less frequent reinterventions for stent reobstruction, migration, or stent fracture (3.2% uncovered group vs 20.7% covered group, P = .0490). The uncovered group had 2 major late complications: bleeding and perforation. All 60 patients died, with a median survival time of 51 days and 62 days, respectively. LIMITATIONS Small-sized, single-center, retrospective study. CONCLUSIONS In palliation for malignant GOO, covered stents were associated with a more frequent need for reintervention than uncovered stents, despite similar outcomes and complications. These results require confirmation in a larger randomized comparison.


Scandinavian Journal of Gastroenterology | 2011

Wire-guided selective cannulation of the bile duct with a sphincterotome: a prospective randomized comparative study with the standard method

Tomoko Nambu; Takeo Ukita; Hiroaki Shigoka; Shigefumi Omuta; Iruru Maetani

Abstract Objective. Wire-guided cannulation (WGC) is expected to reduce the incidence of post-ERCP pancreatitis (PEP). Our aim was to compare the incidence of PEP and the success rate of deep biliary cannulation using WGC or the standard cannulation method with contrast injection (STD). Material and methods. A total of 172 cases with an intact papilla were randomized into the STD group (n = 86) and the WGC group (n = 86). First a trainee endoscopist attempted the cannulation and if it was not successful, an expert endoscopist tried. When the cannulation was not successful within 10 min, the other method was conducted as a second attempt. The primary endpoint was the incidence of PEP and the secondary endpoint was the success rate of selective cannulation. Results. In successful cases, PEP occurred in 6.5% in the STD group and 3.0% in the WGC group in the first attempt. Overall rate of PEP was 6.0% (3, mild; 1, moderate and 1, severe) in the STD group and 2.3% (2, mild) in the WGC group, which were not significantly different. Selective cannulation rate in the first attempt was 73.8% in the STD group and 77.9% in the WGC group. After a crossover, the cannulation was successful in the second attempt in 36.4% and 42.1% and finally in 95.2% and 100% by the STD and WGC method, respectively. Conclusions. The incidence of PEP tended to be lower in the WGC method compared to the STD method. In addition, all cases of pancreatitis in the WGC group were mild. The success rate of cannulation was comparable between two groups.


Digestive Endoscopy | 2014

Placement of a triple‐layered covered versus uncovered metallic stent for palliation of malignant gastric outlet obstruction: A multicenter randomized trial

Iruru Maetani; Yoshinori Mizumoto; Hiroaki Shigoka; Shigefumi Omuta; Michihiro Saito; Junya Tokuhisa; Toshio Morizane

Usually, uncovered self‐expandable metallic stents (SEMS) are used for palliation of malignant gastric outlet obstruction (GOO). A triple‐layered covered SEMS is reported to be efficacious, but its performance has not been compared with uncovered SEMS. The present study is the first to compare the efficacy and safety of a triple‐layered covered versus uncovered SEMS.


Digestive Endoscopy | 2010

Comparison of ultraflex and niti-s stents for palliation of unresectable malignant gastroduodenal obstruction.

Iruru Maetani; Takeo Ukita; Tomoko Nambu; Hiroaki Shigoka; Shigefumi Omuta; Takuro Endo; Kei Takahashi

Aim:  Self‐expandable metallic stents are widely used for palliation of malignant gastric outlet obstruction (GOO), but clinical outcomes of different stents have not been compared. Here, we compared outcomes in patients with a GOO receiving either an Ultraflex (UF) or a Niti‐S (NS) stent.


Diseases of The Colon & Rectum | 2012

Favorable long-term clinical outcome of uncovered D-weave stent placement as definitive palliative treatment for malignant colorectal obstruction.

Kenji Tominaga; Iruru Maetani; Koichiro Sato; Hiroaki Shigoka; Shigefumi Omuta; Sayo Ito; Yoshinori Saigusa

BACKGROUND: Most self-expandable metallic stents for colorectal placement are uncovered because of the high migration rate of covered stents. However, the optimal stent design for colorectal use remains unclear. OBJECTIVE: The purpose of this study was to evaluate the efficacy and safety of a double-wire woven uncovered stent for definitive palliative treatment of malignant colorectal obstruction. DESIGN: This study was a prospective, single-arm, observational clinical study of patients enrolled between December 2005 and September 2010. SETTINGS: This study was conducted at a referral hospital in Japan. PATIENTS: Twenty-four consecutive patients with malignant colorectal obstruction were included in the study. INTERVENTIONS: A double-wire woven uncovered stent was placed by use of a standard through-the-scope endoscopic placement technique. MAIN OUTCOME MEASURES: Technical, initial clinical, and long-term clinical success were measured. Long-term clinical success was defined as sustained relief of obstructive symptoms without reintervention until the patient’s death. RESULTS: The Karnofsky performance status score before stent placement was 60 (median, interquartile range, 42.5–67.5). Twenty of 24 patients had primary colorectal cancer, and 4 had extracolorectal malignancies. The site of obstruction was the ascending colon in 10 patients, descending colon in 4 patients, sigmoid colon in 7 patients, and rectum in 3 patients. Technical, initial, and long-term clinical success rates were 100%, 100%, and 83%. Median stent patency time was 149 days (interquartile range, 45–198 days). Median survival time after stent placement was 155 days (interquartile range, 68–231 days). Four patients (17%) had negative outcomes including stent occlusion by tumor ingrowth (8%) and stent migration (8%). The highest Karnofsky performance status score after stent placement was 70 (median; interquartile range, 50–70). The Karnofsky performance status score improved after stent placement (p = 0.002). LIMITATIONS: This study was limited because it was a single-arm, single-center study, and it had a small sample size. CONCLUSIONS: Endoscopic placement of double-wire woven uncovered stents is effective and safe as definitive palliative treatment for patients with malignant colorectal obstruction.


Digestive Endoscopy | 2012

Comparison of modified introducer method with pull method for percutaneous endoscopic gastrostomy: prospective randomized study.

Hiroaki Shigoka; Iruru Maetani; Kenji Tominaga; Katsushige Gon; Michihiro Saitou; Yukio Takenaka

Aim:  The pull method is associated with a high incidence of percutaneous endoscopic gastrostomy (PEG) site infection. The introducer method has been shown to be less likely to cause infection, because it avoids the passage of a tube through the oropharynx. The aim of the present study was to compare the modified introducer method with the pull method for PEG.


World Journal of Gastroenterology | 2015

Is endoscopic papillary large balloon dilatation without endoscopic sphincterotomy effective

Shigefumi Omuta; Iruru Maetani; Michihiro Saito; Hiroaki Shigoka; Katsushige Gon; Junya Tokuhisa; Mieko Naruki

AIM To evaluate the safety and efficacy of endoscopic papillary large balloon dilatation (EPLBD) without endoscopic sphincterotomy in a prospective study. METHODS From July 2011 to August 2013, we performed EPLBD on 41 patients with naïve papillae prospectively. For sphincteroplasty of EPLBD, endoscopic sphincterotomy (EST) was not performed, and balloon diameter selection was based on the distal common bile duct diameter. The balloon was inflated to the desired pressure. If the balloon waist did not disappear, and the desired pressure was satisfied, we judged the dilatation as complete. We used a retrieval balloon catheter or mechanical lithotripter (ML) to remove stones and assessed the rates of complete stone removal, number of sessions, use of ML and adverse events. Furthermore, we compared the presence or absence of balloon waist disappearance with clinical characteristics and endoscopic outcome. RESULTS The mean diameters of the distal and maximum common bile duct were 13.5 ± 2.4 mm and 16.4 ± 3.1 mm, respectively. The mean maximum transverse-diameter of the stones was 13.4 ± 3.4 mm, and the mean number of stones was 3.0 ± 2.4. Complete stone removal was achieved in 97.5% (40/41) of cases, and ML was used in 12.2% (5/41) of cases. The mean number of sessions required was 1.2 ± 0.62. Pancreatitis developed in two patients and perforation in one. The rate of balloon waist disappearance was 73.1% (30/41). No significant differences were noted in procedure time, rate of complete stone removal (100% vs 100%), number of sessions (1.1 vs 1.3, P = 0.22), application of ML (13% vs 9%, P = 0.71), or occurrence of pancreatitis (3.3% vs 9.1%, P = 0.45) between cases with and without balloon waist disappearance. CONCLUSION EST before sphincteroplasty may be unnecessary in EPLBD. Further investigations are needed to verify the relationship between the presence or absence of balloon waist disappearance.


World Journal of Gastroenterology | 2013

Newly designed J-shaped tip guidewire: a preliminary feasibility study in wire-guided cannulation.

Shigefumi Omuta; Iruru Maetani; Hiroaki Shigoka; Katsushige Gon; Michihiro Saito; Junya Tokuhisa; Mieko Naruki

AIM To perform wire-guided cannulation using a newly designed J-shaped tip guidewire, and to verify feasibility and safety for use. METHODS The study was conducted on endoscopic retrograde cholangiopancreatography (ERCP) patients with naïve papilla undergoing diagnosis and treatment of biliary diseases between September 2011 and July 2012. We performed ERCP in a succession of 50 cases with a J-shaped tip guidewire. The first insertion attempt began with a trainee who had 5 min to complete cannulation, followed if necessary by the trainer for another 5 min. We assessed the primary success rate of selective biliary cannulation within 10 min and adverse events such as post-ERCP pancreatitis (PEP), bleeding or perforation. RESULTS The primary success rate was 90% (45/50) within 10 min, the initial success rate within 5 min by trainee staff was 76% (38/50). The rate of PEP was 6% (3/50), but all 3 cases were mild pancreatitis. All patients were managed successfully with conservative treatment. There was no bleeding or perforation. CONCLUSION A newly designed J-shaped tip guide-wire has the possibility to facilitate selective biliary cannulation for ERCP and appears to be safe.


Hepatobiliary & Pancreatic Diseases International | 2014

Direct Peroral Cholangioscopy Using an Ultraslim Upper Endoscope for Biliary Lesions

Shigefumi Omuta; Iruru Maetani; Takeo Ukita; Tomoko Nambu; Katsushige Gon; Hiroaki Shigoka; Yoshinori Saigusa; Michihiro Saito

BACKGROUND The development of direct peroral cholangioscopy (DPOC) using an ultraslim endoscope simplifies biliary cannulation. The conventional techniques are cumbersome to perform and require advanced skills. The recent introduction of the guidewires and balloons has improved the therapeutic outcomes. Here we describe an effective and easier method for performing DPOC using an ultraslim upper endoscope. METHODS Indications for DPOC were the presence of stones on follow-up of patients who had previously undergone complete sphincteroplasty, including endoscopic sphincterotomy or endoscopic papillary large balloon dilatation. Fifteen patients underwent DPOC. An ultraslim endoscope was inserted perorally and was advanced into the major papilla. The ampulla of Vater was visualized by retroflexing the endoscope in the distal second portion of the duodenum, and then DPOC was performed using a wire-guided cannulation technique with an anchored intraductal balloon catheter. RESULTS One patient failed in the treatment due to looping of the endoscope in the fornix of the stomach. Fourteen (93.3%) were successfully treated with our modified DPOC technique. Only one patient (6.7%) experienced an adverse event (pancreatitis) who responded well to conservative management. Residual stones of the common bile duct were completely removed in 3 patients. CONCLUSION The modified method of DPOC is simple, safe and easy to access the bile duct.


Endoscopy International Open | 2013

Factors associated with delayed gastric emptying in patients with stent placement for malignant gastric outlet obstruction

Kenji Tominaga; Iruru Maetani; Hiroaki Shigoka; Shigefumi Omuta; Koichiro Sato; Sayo Ito; Yoshinori Saigusa; Tatsuya Gomi; Ehiichi Kohda

Background and study aims: Delayed gastric emptying (DGE) is an important factor in determining the clinical outcome in patients with stent placement for malignant gastric outlet obstruction but the factors associated with DGE remain unclear. The aim of this study was to investigate whether clinicopathologic data could be used to identify the factors for DGE in such patients. Patients and methods: A prospective, single-arm, observational clinical study was performed in a referral hospital in Japan. A total of 54 patients with stent placement for malignant gastric outlet obstruction were enrolled. A gastric emptying scintigraphy test was performed 1 week after stent placement. The relationship between DGE and clinicopathologic factors was investigated, and also the relationship between DGE and stent patency time, eating period (when the patient was able to maintain oral intake), and survival time. Results: A total of 38.9 % (21 /54) of patients had DGE. The following were identified as independent predictive factors of DGE: opioid use (odds ratio, 5.32; 95 % confidence interval [95 %CI], 1.07 – 26.41; p = 0.04), chemotherapy before stent placement (odds ratio, 8.03; 95 %CI, 1.85 – 34.95; p = 0.006), and smaller stent diameter (odds ratio, 13.59; 95 %CI, 1.72 – 107.41; p = 0.01). No relationship was found between DGE and the level of oral intake, stent patency time, eating period, and survival time. Conclusions: The factors associated with DGE after stent placement include those associated with the patient’s tumor as well as factors relating to their treatment, including stenting. The clinical and functional results after stent placement appear to be unrelated to the gastric emptying findings.

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