Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
Dr. Lee was born in Shanghai, China, and received his college and medical training in the United States. He is fluent in English and three Chinese dialects. He graduated with chemistry departmental honors from Harvey Mudd College. He was appointed president of AOA society at UCLA School of Medicine. He underwent internal medicine residency and gastroenterology fellowship training at Cedars Sinai Medical Center.
Standard upper gastrointestinal endoscopes (120 cm flexible tubes with a
light and camera on their tips) are capable of reaching only a foot or so past
the stomach into the small intestine. If abnormalities are located within this
area, these endoscopes have working channels through which surgical instruments
can be passed so that diagnostic and therapeutic procedures such as biopsy and
electrocautery can be done.
Many abnormalities of the small bowel, however, lie
further along the small intestine beyond the reach of the standard upper
gastrointestinal endoscopes. Sometimes a
colonoscope, similar to the upper
gastrointestinal endoscope but 180 cm in length, can be used to reach a little
further into the small intestine, but the additional reach of colonoscopes is
It is not the length of the endoscope that is the most important
problem in reaching further into the small intestine. The problem is that the
path of the endoscope through the stomach and duodenum is twisty and the
endoscopes curl in the stomach. In addition, the small intestine is not fixed in
place, and this makes advancement of the endoscopes even more difficult.
What is push endoscopy?
Push endoscopy (also referred to as push enteroscopy) is a procedure that allows diagnosis and treatment of
diseases in the upper small intestine. Push endoscopy reaches further into the
small intestine than the standard upper
gastrointestinal endoscopy (also known
as esophagogastroduodenoscopy, EGD).
Endoscopes for push endoscopy are similar
in length to colonoscopes, approximately 200cm and have working channels for
diagnostic and therapeutic procedures. After the endoscope is passed into the
duodenum, a more rigid overtube is passed over the endoscope to straighten its
path. With the overtube in place, the endoscope then can be advanced without
coiling in the stomach.
What are the advantages of push endoscopy?
Push endoscopy is a useful procedure for examining and delivering therapy
in the small intestine. For example, for patients with intermittently bleeding
angiodysplasias (clusters of weakened blood vessels) located in the small
intestine beyond the reach of a standard upper endoscope, push endoscopy can
be helpful in both diagnosing the bleeding site as well as in stopping the
What are the limitations of push endoscopy?
Push endoscopy has its limitations. Its reach is still limited and
cannot diagnose lesions in the distal small intestine (intestine closer to the
colon). The major risks of push endoscopy are the same as other endoscopic
procedures, bleeding and perforation of the intestine, either due to passage of
the endoscope or the accompanying therapeutic procedures. Because of the use of
an overtube, the risk of perforation probably is increased over the risks of an
endoscopy is a procedure that enables the examiner (usually a
gastroenterologist) to examine the esophagus (swallowing tube),
stomach, and duodenum (first portion of small bowel) using a thin, flexible"...