Endoscopy is performed by inserting a fibre-optic telescope containing a light source and instrument channels into the gastrointestinal, respiratory and urinary tracts. The operator undertakes the procedure by manipulating the endoscope while viewing a video screen or looking down the eye piece of the instrument.
Endoscopy of the gastrointestinal tract allows the endoscopist to view the lumen of the oesophagus, stomach and proximal half of the duodenum (oesophagogastroduodenoscopy), colon (colonoscopy), and rectum and distal sigmod colon (sigmoidoscopy), and distal rectum and anal canal (proctoscopy). It is usually performed under sedation. Intestinal endoscopy can also be performed at laparotomy (enteroscopy) by making a small incision in the intestine and the surgeon passes the endoscope along the intestinal lumen. Procedures, such as dilatation of strictures, biospy and diathermy ablation of polyps, injection of adrenaline around bleeding gastric and duodenal ulcers, cholangio-pancreatography, removal of common bile duct calculi, injection of haemorrhoids, and tumour phototherapy can be performed using fibreoptic endoscopes.
The upper airway, trachea and proximal bronchi can be inspected by bronchoscopy, which may be performed under local or general anaesthesia. Bronchoscopy is used for diagnosis (e.g. inspection and biopsy of lung tumours) or therapy (e.g. removal of foreign bodies, aspiration of secretions). Anaesthetists ocassionally use the fibre-optic bronchoscope to facilitate difficult endotracheal intubation. (see also Common topics in thoracic surgery).
The urethra (urethroscopy), bladder (cystoscopy), and ureters (ureteroscopy) can be inspected for diagnostic purposes. Extensive therapeutic procedures (e.g. resection of the prostate, diathermy and excision of bladder tumours, extraction of calculi) can be performed safely with far less morbidity than the equivalent open procedures.
Endoscopic surgery is performed by inserting a microchip video camera with a light source and specially crafted long-handled surgical instruments into a body cavity by way of small incisions. The surgeon undertakes the procedure by manipulating the instruments while viewing a video screen.
The advantages of endoscopic or ‘closed’ surgery are reduced post-operative pain and analgesic requirements, earlier discharge from hospital, and earlier return to normal function. However, many surgical procedures either cannot be undertaken endoscopically because of their very nature, or cannot be completed endoscopically because of difficulty or patient safety, in which case the operation is converted to an ‘open’ procedure. Some procedures use endoscopic techniques to assist with the procedure and an incision is made to either complete the operation or deliver the resected specimen (e.g. bowel resection, nephrectomy, splenectomy). The range of endoscopically performed operations in many surgical specialties has increased enormously over the last 10–15 years.