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Dive into the research topics where Masafumi Tomita is active.

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Featured researches published by Masafumi Tomita.


Digestive Endoscopy | 2005

USE OF SHORT NEEDLE KNIFE FOR ESOPHAGEAL ENDOSCOPIC SUBMUCOSAL DISSECTION

Takashi Toyonaga; Eisei Nishino; Takashi Hirooka; Toshio Dozaiku; Takeshi Sugiyama; Yoshinori Iwata; Wataru Ono; Chie Ueda; Masafumi Tomita; Tomoomi Hirooka; Shinichiro Makimoto; Akira Hayashibe; Tetuo Sonomura

Background:u2002 The emergence of endoscopic submucosal dissection (ESD) has enabled en bloc resection of lesions, which were conventionally difficult. However, ESD has problems of technical difficulty and high incidence of complications. In order to improve the procedure of marking and submucosal dissection in the esophagus, we modified and adjusted the standard needle knife to a short needle knife having a tip portion with a projection length of 1.5u2003mm.


World Journal of Gastrointestinal Surgery | 2015

Delayed esophageal perforation occurring with endoscopic submucosal dissection: A report of two cases

Yasuhiro Matsuda; Naoki Kataoka; Tomoyuki Yamaguchi; Masafumi Tomita; Kazuki Sakamoto; Shinichiro Makimoto

We report two cases of delayed esophageal perforation occurring with endoscopic submucosal dissection. Our cases involved delayed perforation after 10 d in case 1 and after 6 d in case 2. Both cases were related to solid food. We performed subtotal esophagectomy with gastric tube reconstruction of the esophagus via the subcutaneous route anterior to the thoracic wall without conservative treatment because both cases involved chest pain and major leakage of food into the mediastinum. Postoperative complications were a local factor (including suture failure and esophageal stricture) in case 1, and we performed endoscopic balloon dilatation five times for esophageal stricture. There was no intrathoracic and mediastinal infection in either case. Surgical treatment for delayed esophageal perforation can be performed safely and surely if diagnosis and assessment are not delayed.


World Journal of Gastrointestinal Surgery | 2015

Pancreatectomy and splenectomy for a splenic aneurysm associated with segmental arterial mediolysis

Yasuhiro Matsuda; Kazuki Sakamoto; Eisei Nishino; Naoki Kataoka; Tomoyuki Yamaguchi; Masafumi Tomita; Arito Kazi; Masahiro Shinozaki; Shinichiro Makimoto

Segmental arterial mediolysis (SAM) is characterized by intra-abdominal, retroperitoneal bleeding or bowel ischemia, and the etiology is unknown. A 44-year-old man complaining of abdominal pain was admitted to our hospital. He had been admitted for a left renal infarction three days earlier and had a past medical history of cerebral aneurysm with spontaneous remission. The ruptured site of the splenic arterial aneurysm was clear via a celiac angiography, and we treated it using trans-arterial embolization. Unfortunately, the aneurysm reruptured after two weeks, and we successfully treated it with distal pancreatomy and splenectomy. We recommended a close follow-up and prompt radiological or surgical intervention because SAM can enlarge rapidly and rupture.


Surgical Endoscopy and Other Interventional Techniques | 2018

Self-expandable metallic stenting as a bridge to surgery for malignant colorectal obstruction: pooled analysis of 426 patients from two prospective multicenter series

Masafumi Tomita; Shuji Saito; Shinichiro Makimoto; Shuntaro Yoshida; Hiroyuki Isayama; Tomonori Yamada; Takeaki Matsuzawa; Toshiyuki Enomoto; Rika Kyo; Toshio Kuwai; Nobuto Hirata; Mamoru Shimada; Tomio Hirakawa; Koichi Koizumi; Yoshihisa Saida

BackgroundSelf-expandable metallic stenting (SEMS) for malignant colorectal obstruction (MCO) as a bridge to elective surgery (BTS) is a widely used procedure. The aim of this study was to assess short-term outcomes of SEMS for MCO as BTS.MethodsThis study analyzed pooled data from BTS patients who were enrolled in two multicenter prospective single-arm observational clinical studies that used different stent types. Both studies were conducted by the Japan Colonic Stent Safe Procedure Research Group (JCSSPRG). The first study evaluated the WallFlex™ colonic stent for BTS or palliative treatment (PAL) from May 2012 to October 2013 and the second evaluated the Niti-S™ colonic stent from October 2013 to May 2014. Fifty-three facilities in Japan participated in the studies. Before each study started, the procedure had been shared with the participating institutions by posting details of the standard methods of SEMS placement on the JCSSPRG website. Patients were followed until discharged after surgery.ResultsA total of 723 consecutive patients were enrolled in the two studies. After excluding nine patients, the remaining 714 patients were evaluated as a per-protocol cohort. SEMS placement was performed in 426 patients (312 WallFlex and 114 Niti-S) as BTS and in 288 as PAL. In the 426 BTS patients, the technical success rate was 98.1% (418/426). The clinical success rate was 93.8% (392/418). SEMS-related preoperative complications occurred in 8.5% of patients (36/426), perforations in 1.9% (8/426), and stent migration in 1.2% (5/426). Primary anastomosis was possible in 91.8% of patients (391/426), 3.8% of whom (15/393) had anastomosis leakage. The overall stoma creation rate was 10.6% (45/426). The postoperative complication rate was 16.9% (72/426) and mortality rate was 0.5% (2/426).ConclusionsSEMS placement for MCO as BTS is safe and effective with respect to peri-procedural outcomes. Further investigations are needed to confirm long-term oncological outcomes.


International Journal of Surgery Case Reports | 2017

A case report of primary pancreatic leiomyosarcoma requiring six additional resections for recurrences

Shinichiro Makimoto; Kotaro Hatano; Naoki Kataoka; Tomoyuki Yamaguchi; Masafumi Tomita; Eisei Nishino

Highlights • Primary pancreatic leiomyosarcoma is extremely rare, and is considered to be a highly aggressive malignancy.• We performed distal pancreatectomy, splenectomy, and wide resection of the transverse mesocolon.• Due to treat recurrent tumors, six additional resections were needed over a 5-year period.• Even if a primary pancreatic tumor recurs, long-term survival is achievable by repeated resection of recurrent tumors.


Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 2005

A CASE OF HUGE HEPATOBILIARY CYSTADENOMA WITH OVARIAN-LIKE STROMA

Shinichiro Makimoto; Masafumi Tomita; Kazuki Sakamoto; Masaya Shinbo; Akira Hayashibe; Takeshi Nakamoto


World Journal of Gastrointestinal Surgery | 2017

Perforation associated with endoscopic submucosal dissection for duodenal neoplasm without a papillary portion

Yasuhiro Matsuda; Kazuki Sakamoto; Naoki Kataoka; Tomoyuki Yamaguchi; Masafumi Tomita; Shinichiro Makimoto


Nippon Daicho Komonbyo Gakkai Zasshi | 2018

Eight Cases of Transanal Rectal Foreign Body Extraction Based on an Analysis of 96 Japanese Literature Reports

Tomoya Takami; Tomoyuki Yamaguchi; Kotaro Hatano; Masafumi Tomita


The Journal of the Japan Society for Respiratory Endoscopy | 2015

Endoscopic Bronchial Occlusion with the Endobronchial Watanabe Spigot for Ventilator-associated Intractable Pneumothorax

Yasuhiro Matsuda; Naoki Kataoka; Tomoyuki Yamaguchi; Masafumi Tomita; Kazuki Sakamoto; Arito Kaji; Masahiro Shinozaki; Shinichiro Makimoto


Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 2013

A case of rectal small cell carcinoma diagnosed as squamous cell carcinoma after chemoradiation therapy

Masafumi Tomita; Eisei Nishino; Yasuhiro Matsuda; Tomoyuki Yamaguchi; Naoki Kataoka; Kazuki Sakamoto

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Eisei Nishino

Wakayama Medical University

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Shuji Saito

Yokohama City University

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