Hiroyuki Nitta

Prof. Dr. Hiroyuki Nitta

Department of Surgery, Iwate Medical University School of Medicine, Yahaba, Iwate, Japan
orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 March 2010 in Annals of Surgery
Verified
Journal Article
Closed access
HNHiroyuki Nitta
Hiroyuki Nitta
ASAkira Sasaki
Akira Sasaki
TFTomohiro Fujita
Tomohiro Fujita
HIHidenori Itabashi
Hidenori Itabashi
KHKoichi Hoshikawa
Koichi Hoshikawa
GWGo Wakabayashi
Go Wakabayashi
To assess the feasibility, safety, and short-term outcomes of laparoscopy-assisted major liver resections. The number of reports of laparoscopic major hepatectomies has gradually increased, and living donor hepatectomies for liver transplant have also recently been performed. However, because of the high degree of proficiency required, major hepatectomies have not been widespread. We developed an original procedure in which the liver is mobilized laparoscopically and resected by a hanging technique through a small incision. Between November 2002 and December 2008, 43 patients underwent laparoscopy-assisted major liver resections (LAMLRs) in our institution for hepatocellular carcinoma, metastatic liver cancer, and benign diseases. LAMLRs were completed for 42 patients (97.7%). The median age was 62 years (range: 24-83 years). Preoperative diagnoses were hepatocellular carcinoma (n = 15), metastatic liver cancer (n = 19), and benign disease (n = 8). The types of liver resection consisted of the following: right trisectionectomy (n = 2), right hepatectomy (n = 14), left hepatectomy (n = 16), trisegmentectomy 4, 5, 8 (n = 2), right anterior sectionectomy (n = 4), and extended right posterior sectionectomy (n = 4). The median operating time was 317 minutes (range: 192-542 minutes) and median blood loss was 631 mL (range: 68-2785 mL). There were neither perioperative deaths nor reoperations. Five patients (11.9%) experienced postoperative complications, 2 patients (4.8%) showed bile leakage, and 3 patients (7.1%) developed wound infections. The median postoperative hospital stay was 13.5 days (range: 6-154 days). LAMLR with the hanging technique can be completed safely. The procedure can be performed by open liver surgeons; and thus may be widely performed in the future.

4 July 2020 in Journal of Hepato-Biliary-Pancreatic Sciences
Verified
Journal Article
Open access
PDF file
SHSeiko Hirono
Seiko Hirono
TSToshio Shimokawa
Toshio Shimokawa
YNYuichi Nagakawa
Yuichi Nagakawa
YSYi‐Ming Shyr
Yi‐Ming Shyr
MKManabu Kawai
Manabu Kawai
HYHiroki Yamaue
Hiroki Yamaue
Background/Purpose: Grade C postoperative pancreatic fistula (POPF), as defined by International Study Group of Pancreatic Fistula (ISGPF), is the most life‐threatening complication after pancreatoduodenectomy (PD). This study aims to evaluate risk factors for Grade C POPF after PD.Methods: This is a prospective, multicenter study based in Japan and Taiwan. Between December 2014 and May 2017, 3022 patients were enrolled in this study and 2762 patients were analyzed. We analyzed risk factors of Grade C POPF based on the updated 2016 ISGPF scheme (organ failure, reoperation, and/or death).Results: Among 2762 patients, 46 patients (1.7%) developed Grade C POPF after PD. The mortality rate of the 46 patients with Grade C POPF was 37.0%. On the multivariate analysis, six independent risk factors for Grade C POPF were found; BMI ≥ 25.0 kg/m2, chronic steroid use, preoperative serum albumin <3.0 mg/dL, soft pancreas, operative time ≥480 minutes, and intraoperative transfusion. The c‐statistic of our risk scoring model for Grade C POPF using these risk factors was 0.77. The score was significantly higher in Grade C POPF than in Grade B POPF (P < .001) or none/biochemical leak (P < .001).Conclusions: This prospective study showed risk factors for Grade C POPF after PD.

12 October 2012 in Journal of Hepato-Biliary-Pancreatic Sciences
Verified
Journal Article
Open access
PDF file
HNHiroyuki Nitta
Hiroyuki Nitta
ASAkira Sasaki
Akira Sasaki
YOYuichiro Otsuka
Yuichiro Otsuka
MTMasaru Tsuchiya
Masaru Tsuchiya
HKHironori Kaneko
Hironori Kaneko
GWGo Wakabayashi
Go Wakabayashi
Purpose To assess the types of liver resection, surgical approaches, and surgical outcomes, a questionnaire survey was undertaken at 32 member hospitals of the Japanese Endoscopic Liver Study Group. Methods/results Laparoscopic liver resections were performed on 837 patients. Major hepatectomy, including trisectionectomy, hemihepatectomy, and sectionectomy, constituted 106 of the cases. Laparoscopic major hepatectomy (LMH) was performed as totally laparoscopic (n = 8) (7.5 %), hand‐assisted (n = 4) (3.8 %), or laparoscopy‐assisted (n = 94) (88.7 %). None of the 106 patients were converted to open surgery. Complications occurred in 18 (17.0 %) of the 106 patients. One patient (0.9 %) had bleeding, two (1.9 %) had liver failure, six (5.7 %) had bile leakage, two (1.9 %) had pleural effusion, five (4.7 %) had surgical site infection, one (0.9 %) had pneumonia, and one (0.9 %) had acute respiratory distress syndrome. There were no perioperative deaths or gas embolisms. Conclusion In conclusion, a major hepatectomy using a hybrid technique is safe and feasible.

1 January 2017 in Endocrine Journal
Verified
Journal Article
Open access
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AUAkira Umemura
Akira Umemura
ASAkira Sasaki
Akira Sasaki
HNHiroyuki Nitta
Hiroyuki Nitta
SBShigeaki Baba
Shigeaki Baba
TATaro Ando
Taro Ando
IYISHIGAKI YASUSHI
ISHIGAKI YASUSHI
This study aimed to assess the relationship between the metabolic effect after laparoscopic sleeve gastrectomy (LSG) in morbidly obese Japanese patients, with or without type 2 diabetes mellitus (T2DM), and improved pancreatic steatosis (PS). The study enrolled 27 morbidly obese Japanese patients who were undergoing LSG. Their clinical and metabolic effects were evaluated at baseline and six months after LSG. Pancreas volume (PV), pancreatic attenuation (PA), and splenic attenuation (SA) were measured using a 64-row computed tomography (CT). Changes in PV, PA-SA, and PA/SA were evaluated. The mean body-weight loss, body mass index loss, and percentage of excess weight loss (%EWL) were -34.4 kg (p < 0.001), -11.0 kg/m2 (p < 0.001), and 43.7%, respectively. The mean PV was 96.7 mL at baseline, and it decreased six months after LSG (-16.3mL, p < 0.001). The mean PA significantly increased six months after LSG (9.5 HU, p < 0.001). PA-SA (-23.2 HU vs. -13.3 HU, p = 0.003), and PA/SA (0.54 vs. 0.73, p < 0.001) also significantly increased six months after LSG. In T2DM patients, decreased PV correlated with decreased fasting blood sugar, decreased insulin, and reduced liver volume. In conclusion, PV significantly decreased after LSG in morbidly obese Japanese patients, and that decrease correlated with improvements in PS. In addition, PS plays an important role of development and progression of insulin resistance and T2DM.

1 September 2014 in Journal of Gastrointestinal Surgery
Verified
Journal Article
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NINaoko Ito
Naoko Ito
TITakeshi Iwaya
Takeshi Iwaya
KIKenichiro Ikeda
Kenichiro Ikeda
YKYusuke Kimura
Yusuke Kimura
YAYuji Akiyama
Yuji Akiyama
GWGo Wakabayashi
Go Wakabayashi

4 December 2021 in Journal of Hepato-Biliary-Pancreatic Sciences
Verified
Journal Article
Closed access
PDF file
HKHiroyuki Kato
Hiroyuki Kato
KKKeiko Kamei
Keiko Kamei
HSHironobu Suto
Hironobu Suto
TMTakeyuki Misawa
Takeyuki Misawa
MUMichiaki Unno
Michiaki Unno
YTYoshifumi Takeyama
Yoshifumi Takeyama