Dr. Sumiyama graduated Jikei University School of Medicine in 1998. He completed two year-residency at Jikei University Hospital in 2000. He received PhD degree from Jikei University Graduate School of Medicine in 2003. Since Dec. 2003, he has been promoting a series of both basic and clinical research projects in the gastrointestinal endoscopy field as a primary investigator at Jikei University since 2003.

He was also a former post-doctoral fellow at Mayo Clinic College of Medicine (2005-7) and achieved a lot of internationally recognized developmental researches for novel endoscopic therapies including Confocal Laser Endomicroscopy Submucosal Endoscopy, NOTES and endoscopic full thickness resection.

He has published more than 200 papers and 300 abstracts. He was awarded many academic honors including top reviewer award from the American Society of Gastrointestinal Endoscopy and Oral free paper prize at 19th United European Gastroenterology Week.