ENDOSCOPIC PROCEDURES



Endoscopic examination of the gastrointestinal (GI) tract was first achieved using rigid, multi-lensed instruments that were difficult to use, permitted limited visualization, and were often traumatic to the patient. The development of fiberoptic instruments has revolutionized gas­trointestinal endoscopy and hence the manage­ment of many gastrointestinal disorders. Cur­rently,-a wide range of instruments is available, some tailor-made for specialized applications. The modern fiberoptic endoscope provides a true extension of the eyes and hands of the physician. These instruments combine wide-angle visualiz­ation of the GI tract with flexibility and ability to control the movement of the tip of the scope up to 360 degrees, as well as good patient tolerance.

Most endoscopes include multipurpose chan­nels for passage of air and water, as well as for aspirating fluid out of the GI tract. They also per­mit the passage of a number of instruments, in­cluding cytology brushes, biopsy forceps, injec­tion needles, electrocautery snares, wire baskets, electrocautery, and laser probes.

As discussed earlier, endoscopy has certain dis­tinct advantages over barium contrast radiological examination of the GI tract: (1) It has greater sen­sitivity for mucosal lesions often missed by bar­ium studies. (2) Endoscopy allows greater diag­nostic specificity in certain situations. For example, in a patient with gastrointestinal hem­orrhage, a lesion identified by barium contrast ra­diology will not necessarily be responsible for the bleeding. This uncertainty is eliminated by the direct visualization of actively bleeding lesions permitted by endoscopy. (3) Endoscopy permits biopsy or cytology of lesions at the time of visu­alization. (4) Endoscopy combines therapeutic ca­pabilities with direct visualization of the gastroin­testinal tract, e.g., enabling injection of bleeding esophageal varices at the time of diagnosis. En­doscopy carries the two disadvantages of higher cost , and higher patient morbidity and mortality, although the latter is extremely small for nontherapeutic endoscopy (0.001 per cent). Endoscopy is also often inferior to radiology in identifying submucosal or compressive lesions of the gastrointestinal tract as well as disorders of esophageal motility.

Whether endoscopic or radiological examina­tion should be undertaken as a first procedure de­pends upon the clinical problem (e.g., acute bleeding versus abdominal pain), the range of likely diagnoses, the possible need for therapeutic intervention, and cost factors, as well as the fact that radiological and endoscopic techniques are often complementary to one another in obtaining a diagnosis.

Endoscopic examination is generally performed under sedation with parenteral diazepam and me­peridine, with topical anesthetic spray applied to the pharynx for upper endoscopy