The development of fibre-optic endoscopy revolutionized the ability to investigate the gastrointestinal tract. Flexible endoscopes often have a diameter of less than 1 cm, with a control head and a flexible shaft with a manoeuvrable tip. The head is connected to a light source and can transmit images to a video image screen.
All endoscopes have multiple small lumens allowing transmission of air and water and for suction. The suction channel can also be used for the passage of interventional devices, for example biopsy forceps. The ability to transmit air (insufflation) allows the endoscopist to inflate the lumen to obtain optimal views. The water channel provides a means of washing mucosal surfaces, and suction maybe used to remove pools of fluid within the gastrointestinal tract, thus ensuring that all mucosal surfaces are inspected.
Diagnostic indications include the investigation of gastro-esophageal reflux (diagnostic investigation or surveillance endoscopy of Barrett's esophagus).
Therapeutic procedures that can be undertaken include mucosal biopsy, stent insertion for strictures, and dilatation of strictures.
Patient preparation
Informed consent is required, and patients are fasted for 4-6 hours prior to the procedure. Although most patients do not require sedation, the choice is offered and discussed. Sedation involves the use of a short-acting benzodiazepine which provides a sedative and amnesic effect. Monitoringis required (pulse oximetry) with sedation due to the risk of respiratory depression. Antibiotic prophylaxis is administered to patients with heart valve disease to prevent bacterial endocarditis.
Procedure
A mouthguard is used. The endoscope is introduced into the pharynx, then the oesophagus. Patients may retch during this procedure. The endoscope is progressively introduced to inspect the oesophagus, stomach and proximal small bowel (duodenum).
Complications
The overall complication rate is approximately 1 per 1000 with a mortality rate of approximately 1 per 25000. Complications include bleeding, perforation and respiratory arrest (a complication of sedation).
Post procedure care
Patients are monitored in a recovery area until safe for discharge.