Dennis Lee, MD
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.
What is endoscopy?
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 limited.
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 bleeding.
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 endoscope alone.
Last Editorial Review: 3/21/2008
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