Upper Digestive Endoscopy

and Ian A. D. Bouchier²

(1)

Bishop Auckland, UK

(2)

Edinburgh, Midlothian, UK

The exact diagnosis of patients with haematemesis, dyspepsia and other upper abdominal symptoms cannot be made on the history alone. Diseases may simulate each other and different disorders can affect the same patient. Video endoscopy with photography, biopsy and cytology plays a major role in evaluation and management. The technique is safe with a few contraindications, but training and experience are required to yield good results.

2.1 Instruments

A wide range of instruments is available from different manufacturers. For a panendoscopy a forward or oblique-viewing instrument is necessary. Some have a very large biopsy channel which allows particularly satisfactory histology material to be obtained. A modern standard instrument for routine use has an external diameter of about 11.5 mm and a biopsy channel of 3.5 mm. For a full view of the lesser curve of the stomach, the duodenal bulb and the ampulla of Vater, a side-viewing instrument is sometimes necessary. This is the instrument usually employed for retrograde cholangiopancreatography. Specially designed impedance catheters are in development to assist targeted assessment of mucosal disease.

Videoendoscopy systems display the image on screens so that assistants may watch. Videoendoscopy has a crucial role in training and education. The other great advantage of video equipment is improved posture for the operator compared with the earlier fibreoptic technique, though diagnostic yields are identical (Fig. 2.1).

Fig. 2.1

Video gastroscopy in progress 1996 with author

2.2 Procedures

To achieve good results the patient must be convinced of the value of the procedure. It should be explained that they will probably be awake (but drowsy) throughout and that with sedation he may have no recollection of the procedure. It is best to provide an information sheet before the day of the procedure, and to obtain signed consent then.

It is usual to monitor the patient with pulse oximetry by finger clip, and to provide continuous oxygen by nasal catheter throughout the procedure. It is best to have two nursing assistants, one for patient care and one for instrument care. It is desirable to keep room lights on to monitor patient condition.

The stomach must be empty and this is achieved usually by fasting overnight, or for at least 4 h. If the patient has undergone gastric suction for vomiting or if it is necessary to use some form of gastric intubation when brisk haematemesis or gastric outflow obstruction is present it should be remembered that appearances of oesophageal, gastric lesser curve and antral erosions may be produced artefactually

False teeth should be removed. There is considerable variation in the techniques for preparation. If sedation is required a satisfactory one is to give midazolam 2.5–5 mg intravenously,usually by cannula, immediately before the examination, with the patient positioned on the left side. Smaller doses of midazolam (or none at all) may be required in patients with liver decompensation or respiratory failure. Repeat doses may be required in younger patients. It is rarely useful to exceed 5 mg midazolam and paradoxical hyperactivity can occur. The effect of benzodiazepine sedation can be rapidly reversed if necessary by IV administration of flumazenil 0.5 mg. Doxapram 100 mg IV is less specific but can be useful if excessive respiratory depression occurs.

In patients who prefer not to be sedated a lignocaine throat spray can be useful: it is safest not to use both sedation and throat spray.

A plastic gag with a central aperture to admit the endoscope is necessary to prevent the instrument being bitten. The endoscope is lubricated with water or clear jelly, and the light and suction equipment is tested before passage. The patient’s head is flexed and the instrument tip is passed over the tongue to the oropharynx while an assistant holds the end with the controls. The patient is then asked to give a couple of swallows to assist passage into the oesophagus. If the patient does not comply the instrument may impact in the pharynx or enter the trachea. In either case the patient may choke and splutter, develop wheezing or coughing, and become cyanosed. If this happens the instrument should be withdrawn and a further attempt at passage made. If the trachea is entered the rough feel of the cartilages is experienced, and the branching pattern of the trachea is identified under direct vision. Guidance of the tip with a fmger in the patient’s mouth can be helpful. In practice the oesophagus can usually be entered without difficulty.

2.2.1 Oesophagus (Fig. 2.2)

A good view of the oesophagus can be obtained on entry, but only usually over its lower two-thirds. Air insufflation assists vision but should be used sparingly. The presence of macroscopic oesophagitis, Mallory-Weiss tears, stricture or carcinoma can be detected readily. Mallory-Weiss tears are linear white ulcerated areas with surrounding erythema related to the level of the diaphragm. They are produced by the effort of retching or vomiting and usually occur at the gastro-oesophageal junction; in patients with hiatus hernia however, they are found in the cardia of the stomach. Oesophagitis is usually caused by retrograde reflux and extends proximally from the gastro-oesophageal junction. Mild oesophagitis is recognized by erythema, loss of surface glistening, vascular injection and friability. More severe changes lead to erosions, plaque formation and spontaneous bleeding. Discrete ulcers and benign strictures also occur, and in chronic oesophagitis the junction of the squamous and columnar epithelium can migrate proximally (Barrett’s oesophagus).

Fig. 2.2

The upper gastrointestinal tract

Forceps passed down the biopsy channel of the instrument can obtain multiple 2–3 mm samples which can be studied histologically to provide proof of diagnosis. Unless there is obvious tumour or Barrett’s oesophagus, it is best to take samples at least 5 cm above the gastro-oesophageal junction (usually above the level of the diaphragm and lower oesophageal sphincter), since distal changes are common in healthy individuals. Samples are immediately immersed in formol saline. Cytology brushes can also be passed in the same way using a plastic catheter to protect the sample on withdrawal before immersing in fixative. It is recommended that four biopsies and cytology brushings should be taken. If all are negative for carcinoma then this diagnosis is very unlikely in the oesophagus, though this is less certain for the stomach.

Occasionally a tight stricture cannot be passed: undue force must not be used. Gentle persuasion may pass the instrument through lesser strictures and give symptomatic relief. It may be possible to identify a hiatus hernia, though this is not always reliable.

The upper oesophagus and some of the pharynx can usually be seen with the narrow calibre instruments on withdrawal. Rigid oesophagoscopy by an ENT surgeon may be necessary if the post-cricoid region is under suspicion.

2.2.2 Stomach

On passing over the normal gastro-oesophageal junction there is a change from pale pink mucosa to the orange-red mucosa of the stomach. This does not always correlate with histological change in the epithelium. The appearance of stomach mucosa is different from that of the high pressure zone of the lower oesophageal sphincter, and normally lies below the level of the diaphragm, if this can be detected.

The greater curve and the antrum are easily viewed, with air insufflation if necessary, but the rest of the stomach is more difficult to examine adequately. The greater curve is recognized by its rippling longitudinal folds; the antrum is smooth. The cardia can be seen well only by putting a J-bend on the end of the instrument when it reaches the pylorus and looking back towards the oesophagus. A partial view of the lesser curve is obtained as the instrument slides over it, but again a reverse loop may be necessary to view it completely. A sharp angle or incisura may hide a small distal lesion. There is often a pool of gastric juice on the greater curve: this may be aspirated, though care is needed to avoid damaging the mucosa. The pool can be moved by altering the patient’s position slightly, or even lying them supine temporarily, allowing a full view to be obtained.

Gastritis is often distal and is recognized by loss of surface glistening, granularity, vascular injection and friability. There may be haemorrhage or superficial erosions. Some gastritis is usual after gastric surgery, in which pyloric reflux is increased, and its significance is doubtful. Transient erythema caused by retching is also of no significance. In atrophic gastritis the stomach appears exceptionally smooth and is often pale. The autoimmune gastritis which causes pernicious anaemia is associated with a characteristic undulating knobbly appearance. The correlation between macroscopic gastritis and histology is poor. Ulcers are easily recognized: biopsies should ideally be taken from the four quarters of the rim and from the base unless there has been recent bleeding.

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