#non #cardia #gastric #cancer
1. Upper Endoscopy: Overview
Joseph Sung Peter Cotton
Young endoscopists may be surprised to hear that the first commercial gastroscopes of the modern (fiber-optic) era, in the late 1960s, were indeed gastroscopes. They had side-viewing optics and were designed to examine only the stomach, using appropriate rotation, and some up down tip deflection.
This design grew out of the preoccupation of the Japanese with their burden of gastric cancer (and followed the widespread use of side-aimed gastro-cameras).
Western doctors wanted also to be able to examine the esophagus and duodenum, because of the prevalence of reflux disease, esophageal cancer, and duodenal ulcers. An American company developed the first forward-viewing ‘panendoscope’ in the late 1960s, and esophago-gastro-duodenoscopy (EGD) was born. Through the 1970s, instruments were refined progressively, and the images gradually improved.
The next major technical breakthrough (in the early 1980s) was the introduction of video-endoscopy. This converted a rather ‘private’ experience into a team event, with something for all to see (including the patients).
Video-endoscopy completely revolutionized teaching. Previously the endoscopic view could be shared only through a clumsy side-arm fiber-optic ‘teaching attachment’, but this (at least initially) degraded the quality of both images considerably. Movie and TV cameras were bulky and were used only rarely and with difficulty. Digital capture opened a new world of image recording, manipulation, storage, and transmission.
The next two decades saw considerable changes in the details of endoscope design (e.g. immersibility, minituarization, and control mechanisms), but not in the basics that is until the recent extraordinary development of the capsule endoscope. This is indeed the start of a new era.
The evolution of endoscopy as a clinical tool has been a fascinating journey (at least to those who lived through it), and certainly dramatic. The ability to take target biopsies proved to be a watershed. Before that, endoscopists were scarce animals, and their enthusiasms and opinions were largely ignored, and sometimes ridiculed, by mainstream medicine and gastroenterology.
Biopsy brought almost instant respectability, since pathological reports were and are somehow sancrosanct. This is a little curious, since pathologists are really only endoscopists looking down rigid instruments, but perhaps our trust in their reports speaks to the quality of their training and experience. (There is a message here for endoscopists, who have, at least in the West, paid too little attention to the subtleties of image interpretation, relying on biopsy to sort out anything that looks odd.)
Through the 1970s we gradually accumulated the data (much of it rather biased) to show the superiority of endoscopy over the standard tool of the day the barium meal. But, sceptics continued to argue ‘so what’? For example, an NIH conference in 1980 questioned the value of endoscoping bleeders, since studies did not appear to show any outcome benefit.
One of us argued rather strongly at the time that the failure to show benefit with a more accurate diagnostic tool showed simply that the treatments were inadequate, and needed to be improved. Fortunately this call was answered quickly with the development of endoscopic techniques for hemostasis (and the NIH got the message).
Without question it was the development of effective therapeutic methods that guaranteed the place of digestive endoscopy in the mainstream of clinical practice.
The late 1970s and 1980s saw the establishment of many endoscopic therapies, for the management of dysphagia, foreign bodies, strictures, polyps, and enteral nutrition (in parallel with the exciting developments in other areas, such as colonoscopic polypectomy and biliary sphincterotomy for stone removal). All of these largely replaced more expensive and dangerous surgical procedures, a fact which led sadly to complex ‘turf’ issues, which are still being resolved. The boundary between surgery and interventional endoscopy is artificial and unhelpful. The leaders of our professions must redraw the traditional structures for training and practice- for our patients benefit.
The undoubted success of digestive endoscopy brings significant responsibilities. We have to ensure that these techniques are widely available when needed, and to high quality standards. Training issues are important, and are being addressed thoughtfully. Keeping up to date in practice is an even bigger challenge, since our field continues to expand. We are all busy people, and the literature proliferates. While there is no substitute for reading all of the source data, who has the time?
This ebook/annual series on ‘Advanced Endoscopy’ seeks to help by providing current and authoritative reviews of key areas of interest, concern, and controversy. We are indeed fortunate that so many international authorities have agreed to share their wisdom, and to make sure that it is updated regularly. This section focuses on aspects of Upper Endoscopy. Several related general issues (e.g. disinfection, sedation, and teaching) are covered in the section on ‘Practice’.
Copyright Blackwell Publishing, 2003