An endoscopic instrument (see ENDOSCOPE) for viewing the interior of the STOMACH. Introduced into the stomach via the mouth and OESOPHAGUS, the long ?exible instrument (also called an oesophagogastroduodenoscope) transmits an image through a ?breoptic bundle or by a small video camera. The operator can see and photograph all areas of the stomach and also take biopsy specimens when required. (See also FIBREOPTIC ENDOSCOPY.)
n. an illuminated optical endoscope used to inspect the interior of the gullet (oesophagus), stomach, and duodenum. For many years these were rigid or semi-rigid instruments affording only limited views, but their modern counterparts are flexible instruments that house advanced digital systems to allow high-definition imaging of the oesophagus, stomach, and the proximal segments of the duodenum. Biopsies can be taken of visualized areas of mucosal abnormality, and therapeutic procedures (e.g. to stop a bleeding ulcer, remove a polyp, insert a *gastrostomy, dilate a stricture, or insert a self-expandable metal stent) may be performed. As the same instruments can usually be introduced into the duodenum they are also known as gastroduodenoscopes or oesophagogastroduodenoscopes. —gastroscopy n.
A tube-shaped instrument inserted into a cavity in the body to investigate and treat disorders. It is ?exible and equipped with lenses and a light source. Examples of endoscopes are the CYSTOSCOPE for use in the bladder, the GASTROSCOPE for examining the stomach and the ARTHROSCOPE for looking into joints (see also FIBREOPTIC ENDOSCOPY).... endoscope
n. an illuminated optical instrument used to inspect the interior of the oesophagus (gullet), dilate strictures, obtain material for biopsy, or remove a foreign body. It may be a rigid metal tube or a flexible fibreoptic or video-camera instrument (see gastroscope). —oesophagoscopy n.... oesophagoscope
n. a semirigid plastic tube (25–45 cm long) designed to fit over the shaft of an *endoscope in order to minimize the risk of trauma. It can be used with a *gastroscope, *cholangioscope, *enteroscope, or colonoscope (see colonoscopy). An overtube is placed over the shaft of an endoscope prior to its insertion; once the endoscope is in the desired place, the overtube is lubricated and slid into position over the shaft. It is commonly used in combination with a gastroscope for the removal of ingested foreign bodies (especially those with sharp or serrated edges that may cause significant trauma as they are being extracted).... overtube
n. the formation of a hole in a hollow organ. This may occur in the course of a disease (e.g. perforation from a *duodenal ulcer, or stomach cancer), allowing the flow of intestinal contents into the peritoneal cavity, with subsequent inflammation (*peritonitis), severe abdominal pain, and shock. Treatment is usually by surgical repair of the perforation, but conservative treatment with antibiotics may result in spontaneous healing. Perforations may also be caused by instruments – for example a gastroscope may perforate the stomach or a curette may perforate the uterus – or by injury, for example to the eardrum.... perforation
(PDT, photoradiation therapy, phototherapy, photochemotherapy) 1. a treatment for some types of superficial cancers. A light-sensitive agent (porfimer sodium [Photofrin] or temoporfin [Foscan]) is injected into the bloodstream and remains in cancer cells for a longer time than in normal cells. Exposure to laser radiation produces an active form of oxygen that destroys the treated cancer cells. The laser radiation can be directed through a fibreoptic bronchoscope into the airways, through a gastroscope into the oesophagus, or through a cystoscope into the bladder. PDT causes minimal damage to healthy tissue, but as it cannot pass through more than about 3 cm of tissue, it is restricted to treating tumours on or just under the skin or on the lining of internal organs. Photodynamic therapy makes the skin and eyes sensitive to light for six weeks or more after treatment. 2. a treatment for wet age-related *macular degeneration that involves the intravenous injection of a light-sensitive agent (verteporfin, Visudyne) which passes to the abnormal leaking blood vessels in the retina. The agent is activated when a cold laser light is directed at the macula, sealing the abnormal vessels and thus preventing further leakage and macular damage. The effect is to limit visual loss and stabilize vision.... photodynamic therapy
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