Digestive Diseases Research

Hemostasis Research

Research group

  • CURE Hemostasis Research Group
Dennis M. Jensen, MD

Principal investigator

  • Dennis M. Jensen, MD

Co-investigators

  • Gareth Dulai, MD, MSHS
  • Kevin Ghassemi, MD
  • Thomas Kovacs, MD
  • Gustavo Machicado, MD
  • James Sul, MD, MSEpi
  • Marc Kaneshiro, MD
  • Stephen Kim, MD
  • Alireza Sedarat, MD
  • V. Raman Muthusamy, MD, MAS

Funding

  • NIH-NIDDK. Gastroenterology Training Grant (T32)
  • CURE Digestive Diseases Research Center (DDRC), Human Studies CORE
  • VA Clinical Merit Review Grant
  • ASGE Research Foundation Grant

Current research projects

  • Randomized Controlled Trial (RCT) of a large over-the-scope hemoclip compared to standard endoscopic hemostasis for patients with severe non-variceal UGI bleeding
  • RCT of Doppler assisted risk stratification and hemostasis compared to GI guideline management to prevent severe delayed post-polypectomy induced ulcer (PPIU) hemorrhage in high risk patients
  • Database, retrospective cohort studies and prospective RCT of Dieulafoy’s lesions as a cause of severe UGI, small intestine, or colon hemorrhage
  • Retrospective cohort study of long term outcomes of patients with UGI bleeding from watermelon stomach or portal hypertensive gastropathy treated with MPEC vs. APC
  • Cohort study of the accuracy of CT scans for detection of esophagogastric varices in patients with severe UGI hemorrhage
  • Prospective study of urgent capsule endoscopy for localization and diagnosis of patients with severe hematochezia

Future research directions

  • Multicenter study of OVESCO vs. standard endoscopic hemostasis for severe ulcer and Dieulafoy’s lesion hemorrhage
  • Multicenter study of Doppler assisted endoscopic risk stratification and hemostasis to prevent delayed bleeding after EMR or polypectomy in the colon, stomach or duodenum in high risk patients
  • RCT of Cryotherapy vs. APC for control of chronic GI bleeding in patients with watermelon stomach or portal hypertensive gastropathy
  • Cohort study of delayed EMR or post-polypectomy hemorrhage after resection of UGI benign polyps
  • Cost analyses of OTSC and PPIU RCT’s when enrollment is completed

Key publications - Full list of PubMed publications for Dr. Dennis Jensen

  1. Lin ES, Dutson U & Jensen DM. Low rates of diagnosis and treatment of iron deficiency anemia after an acute severe gastrointestinal hemorrhage. Digestive Diseases and Sciences. 21 March 2025
  2. Jensen DM. The Importance of Arterial Blood Flow Detection for Risk Stratification and Eradication to Achieve Definitive Hemostasis of Severe Non-Variceal UGI Hemorrhage. J. Clin. Med. 2023, 12(20), 6473
  3. Jensen DM. Diagnosis and Treatment of Definitive Diverticular Hemorrhage. Amer J Gastroenterol 2018: In Press
  4. Sung JJY, Chiu P, Chan FK, Lau JYW, Goh KL, Ho KY, Jung HY, Sollano JD, Gotoda T, Reddy N, Singh R, Sugano K, Wu KC, Wuc Y, Bjorkmau DJ, Jensen DM, Kuipers EJ, Lanas A. Asian-Pacific Working Group Consensus on Non-variceal Upper Gastrointestinal Bleeding. An Update 2018. Gut 2018; 0:1-12.doi: 10.1136/gutjn1-2018
  5. Manatsathit W, Jensen DM, Hines J, Kovacs T, Ohning G, Jutabha R, Ghassemi K, Dulai GS, Machicado G. Laparotomy and intraoperative enteroscopy for severe obscure gastrointestinal bleeding before and after the era of video capsule endoscopy and deep enteroscopy. Amer J Surgery 2017: In Press
  6. Jensen DM, Kovacs TOG, Ohning GV, Ghassemi K, Machicado GA, Dulai GS, Sedarat A, Jutabha R, Gornbein J. Doppler Endoscopic Probe Monitoring for Blood Flow Improves Risk Stratification and Outcomes of Patients with Severe Non-Variceal UGI Hemorrhage. Gastroenterology 2017; 152:1310-1318
  7. Jensen DM, Eklund S, Persson, T, Ahlbom H, Stuart R, Barkun AN, Kuipers EJ, Mössner J, Lau JY, Sung, JJ, Kilhamm J, Lind T. Reassessment of Rebleeding Risk of Forrest IB (Oozing) Peptic Ulcer Bleeding in a Large International Randomized Trial. Am J Gastroenterol 2017; 112:441-446
  8. Camus-Duboc M, Khungar V, Jensen DM, Ohning GV, Kovacs TOG, Jutabha R, Ghassemi, K, Machicado GA, Dulai GS. Origin, Clinical Characteristics and 30-day Outcomes of Severe Hematochezia in Cirrhotics and Non-cirrhotics. Dig Dis Sc 2016; 61:2732-40
  9. Camus M, Jensen DM, Kovacs TOG, Jensen ME, Markovic D, Gornbein J. Independent Risk Factors of 30 day Outcomes in 1264 patients with Peptic Ulcer Bleeding in the USA – Large Ulcers do worse. Alim Pharm Ther 2016; 43:1080-1089
  10. Jensen DM, Ohning GV, Kovacs TOG, Ghassemi K, Jutabha R, Dulai GS, Machicado GA. Doppler Endoscopic probe as a guide to risk stratification and definitive hemostasis of peptic ulcer bleeding. Gastrointest Endosc 2016;83: 129-36
  11. Jensen DM, Ohning GV, Kovacs TOG, Jutabha R, Ghassemi K, Machicado GA, Dulai GS. Natural History of Definitive Diverticular Hemorrhage Based Upon Stigmata of Recent Hemorrhage and Doppler Blood Flow Monitoring for Risk Stratification and Definitive Hemostasis. Gastrointest Endosc 2016;83:416-23
  12. Camus M, Jensen DM, Ohning GV, Kovacs TO, Ghassemi KA, Jutabha R, Machicado GA, Dulai GS, Jensen ME, Gornbein JA. Comparison of 3 Risk Scores to Predict Outcomes of Severe Lower Gastrointestinal Bleeding. J Clin Gastroenterol 2016; 50:52-58
  13. Camus M, Jensen DM, Ohning GV, Kovacs TO, Ghassemi KA, Jutabha R, Machicado GA, Dulai GS., Hines JO. Severe Upper Gastrointestinal Hemorrhage from Linear Gastric Ulcers in Large Hiatal Hernias: a Large Prospective Case, Series of Cameron Ulcers. Endoscopy 2013; 45:1-4
  14. Laine L, Jensen DM. ACG Guideline. Management of Patients with Ulcer Bleeding. Am J Gastroenterol 2012; 107:345-360
  15. Chavalitdhamrong D, Jensen DM, Singh B, Kovacs TOG, Carrico M, Han SH, Durazo F, Saab S, Gornbein JA. Is capsule endoscopy accurate enough to screen cirrhotic patients for varices and other lesions? Gastrointestinal Endoscopy 2008 Volume 67, Issue 5, Page AB122

Past GI research fellows

  • Marine Camus, MD
  • Disaya Chavalitdhamrong, MD
  • Daniel Eshtiaghpour, MD
  • M. Philip Fejleh, MD
  • Marie-Anne Guillaumot, MD
  • Vandana Khungar, MD, MSc
  • Shane Manatsathit, MD
  • Neil Marya, MD
  • Benjamin Nulsen, MD
  • Alireza Sedarat, MD

Awards

  • Lifetime Achievement Award (2025) - Presented by the Southern California Society for Gastroenterology
  • Rudolph V. Schindler Award (2012) - Dr. Dennis Jensen was the recipient of the American Society of Gastrointestinal Endoscopy (ASGE) Rudolph V. Schindler Award. This Schindler Award is the society's highest honor, recognizing the person whose accomplishments in endoscopic research, teaching or service to the society exemplifies the standards of Dr. Schindler.

About Dr. Jensen

Dr. Jensen earned his medical degree at the University of Washington Medical School in Seattle. He completed a medical internship and first-year medical residency at University of Oregon and Affiliated Hospitals. He then served as a major in the US Army Medical Corps and was director of a Preventive Medicine Department. Following the Army, he completed a second-year medical residency at Wadsworth Veterans Administration (VA) Hospital in Los Angeles and a fellowship in gastroenterology through a joint program of UCLA and Wadsworth VA Hospitals. He has been on the faculty at these institutions since completion of his GI fellowship training at UCLA.

Dr. Jensen is a professor of medicine (in-residence academic series) and a distinguished research professor of medicine, Department of Medicine at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA). He also served as associate director of the UCLA/CURE: DDRCC where he directed the Human Studies Core. He was a key investigator and on the executive committee of CURE. Currently, he is a staff physician in the UCLA Vatche and Tamar Manoukian Division of Digestive Diseases and a staff physician in the GI Section of the VA Greater Los Angeles Healthcare Center. He is a member of the UCLA DDD Research Council. He directs the VA-CURE Hemostasis Research Group which performs clinical-outcomes research, teaching, and research mentoring at UCLA and West LA VA Hospitals. 

Dr. Jensen’s research interests include multi-center, prospective and randomized controlled trials (RCT’s) of diagnosis and endoscopic hemostasis of gastrointestinal (GI) hemorrhage; primary and secondary prevention of GI bleeding; GI outcomes and health service studies; and technology assessment research related to endoscopy and GI bleeding. He is also studying diagnosis and treatment of patients with iron deficiency anemia after a severe GI hemorrhage. He has been the PI or a co-investigator on many multicenter controlled trials including both national and international studies. He has been continuously funded by investigator-initiated, peer reviewed federal grants since he first joined the UCLA faculty.  These include multiple RO1 studies jointly funded by the National Institutes of Health (NIH) and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Also, he has received research funding from the VA Research Service, Department of Defense (DOD), American Society for Gastrointestinal Endoscopy (ASGE), American College of Gastroenterology (ACG), UCLA Academic Senate, and industry. He has been a member of different study sections (including the VA Merit Review Board and the NIH Reviewers Reserve for special study sections), a reviewer of NIH K23 and K24 career development awards and a member of site visits to centers proposing research in gastrointestinal endoscopy, randomized controlled trials, GI technology, and GI clinical and outcomes research studies.

Dr. Jensen has three different sources of funding for his research and for career development of others, as principal investigator (PI) and director of an NIH T32 GI mentored training. One source of research funding is a Veterans Administration (VA) Research Service Merit Review clinical grant. His current study is a RCT of Doppler endoscopic probe for blood flow monitoring, risk stratification, and focal treatment of arterial blood flow to prevent delayed post-polypectomy induced bleeding in high-risk patients. This is a multicenter RCT now involving VA West Los Angeles, Ronald Reagan UCLA Medical Center and previously at a Los Angeles Kaiser Permanente Hospital. The second source of research funding is from the UCLA Foundation. This is for studies of iron deficiency anemia in patients after a severe GI hemorrhage. Included are both database studies and a RCT interventional study of high dose intravenous iron compared to oral iron for restoration of iron stores and improvement in patients’ clinical outcomes, symptoms and functional status. The third funding source for Dr. Jensen is as the director and PI of an NIH GI T32 training grant which supports research trainees who aspire to become the next generation of investigators and academicians in digestive diseases, GI sciences, and GI surgery. He recently completed research funding from the UCLA (CURE):Digestive Diseases Research Core Center  grant for which he directed the Human Studies Core for more than 25 years. That NIH P30 Center grant provided scientific core services to support the research of many other CURE investigator’s translational, clinical, database, and outcomes studies. 

Dr. Jensen has published more than 310 peer reviewed papers, case reports, chapters, books, editorials, reviews and other reports. He also has published 338 abstracts. He has been on several editorial boards and is a regular reviewer for such peer-reviewed journals as the New England Journal of Medicine, Annals of Internal Medicine, JAMA, Gastroenterology, American Journal of Gastroenterology, Gastrointestinal Endoscopy, Endoscopy, Digestive Diseases and Sciences, and the Medical Letter. He has been an invited faculty member of numerous post-graduate GI courses and NIH consensus conferences on GI hemorrhage, endoscopy research, and GI guidelines for GI bleeding, including local, regional, national, and international symposia. 

Dr. Jensen has successfully mentored many young clinical, outcomes, and endoscopy investigators for research and career development over the last 35 years. Many of his trainees are full-time faculty or clinical faculty at academic medical centers in the US or abroad. He has completed this mentored research training as the PI and director of the UCLA NIH T32 GI training grant for the last 25 years and previously through an NIH K24 Mid-career grant for mentoring and clinical research. He has received both local and national awards as a distinguished lecturer and distinguished mentor, educator, and clinical researcher. Dr. Jensen has served on numerous committees of the ASGE and is a past councilor on the ASGE Governing Board. He also served as a member of the ACG Research Committee. He now serves as a member of the editorial board for Gastrointestinal Endoscopy, the main journal for the ASGE. In May 2012, Dr. Jensen was awarded the Rudolf V. Schindler award, the highest award of the ASGE. In June 2025, he received a Lifetime Achievement Award from the Southern California Society of Gastroenterology. Dr. Jensen continues to have both local and international research trainees for mentoring who are investigating and publishing abstracts, manuscripts, teaching atlases, reviews, and practice guidelines about GI bleeding (including risk stratification, diagnosis, treatments, outcomes, and prevention), clinical outcomes studies of GI diseases and endoscopy, and RCT’s with cost analyses of new GI endoscopic technologies. He also has a large number of research collaborators both in the US and internationally who are active in ongoing GI investigations and consensus conferences as well as creating new teaching atlases, videos, and GI guidelines for GI endoscopy, GI mentoring, or GI hemorrhage. 

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