TECHNIQUES OF UGI ENDOSCOPY AND NORMAL ANATOMYChapter 1

Informed consent and counseling: The patient should be clearly explained about the procedure and the likely discomfort he may experience. He should be convinced that his co-operation will make the procedure easier and quicker.

Overnight fasting: Routine endoscopy is usually performed in the morning hours after overnight fasting. Coating agents like antacids or colored medications should be clearly withheld. In case of obstructed stomach prior nasogastric intubation and lavage should be performed to clear the gastric residue.

Sedation and anesthesia: For routine UGI endoscopy we use only topical pharyngeal anesthetics like lignocaine viscus or spray. Sedation, in the form of intravenous midazolam is occasionally used in children. For therapeutic endoscopy like foreign body removal, stent placement etc., it is our practice to use intravenous propofol anesthesia with or without endotracheal intubation.

Endotracheal intubation and monitoring: Endoscopy in a comatosed or irritable patient is fraught with the risk of aspiration, hypoxia and ‘bite’ damage to the endoscope. It is our practice to use prior endotracheal intubation and also monitor the vital parameters during the procedure.

Instrument check: It is a good practice to check the instrument like light source, suction channel, airflow and display panel for any malfunction.

Position of the patient: Diagnostic endoscopy is always performed in left lateral position. Occasionally in a patient with upper GI bleeding, it may be necessary to examine the patient in right lateral position. This is to displace the blood pooled in the fundus that may obscure the bleeding lesion.

Antibiotic prophylaxis: Antibiotic prophylaxis is not indicated for diagnostic endoscopy. Current recommendations by American Society for Gastrointestinal Endoscopy (ASGE) exclude even conditions like valvular heart disease, prosthetic valves, synthetic vascular graft and prosthetic joints from the ambit of antibiotic prophylaxis. The few indications for antibiotic prophylaxis are, therapeutic endoscopy for cirrhosis with acute variceal bleeding, cyst drainage and in patients with established GI tract infection who have the above listed cardiovascular status.

The mouth-guard is held between the teeth (Fig. 1.1). It is further supported by the index and middle finger of the endoscopy assistant. Alternatively, an elastic band attached to the mouth-guard can be used to keep it steady.

The tip of the endoscope is slightly bent to fit the contour of the tongue. It is gently advanced over the base of the tongue towards the pharynx (Figs 1.2 and 1.3).

The epiglottis (E) is seen as the pharynx is entered (Figs 1.4A and B).

As the scope passes below the epiglottis, the larynx and both pyriform fossae come into view. The scope is kept in the midline at the esophageal inlet (arrow in figs 1.5 and 1.6) and the patient is asked to take swallows. No undue force should be applied at this stage. Entry into the esophagus should be a voluntary effort supplemented by a gentle push by the endoscopist.

While negotiating esophageal inlet, such an appearance indicates passage of endoscope into trachea (Figs 1.7A and B). The patient becomes restless and starts coughing violently. Withdraw the endoscope at once. Reassure the patient and retry entering the esophagus after a while.

Esophageal mucosa is essentially featureless. The tracheal impression can be seen in the proximal esophagus (Fig. 1.8). Aortic impression and pulsation can be observed in the mid-esophagus (Fig. 1.9).

Z line represents the junction of pale squamous epithelium of esophagus with the pink columnar epithelium of stomach (Figs 1.10A to F). The junction may not be quite apparent when it lies at the level of diaphragmatic indentation (arrow in Fig. 1.10a). In most of the cases, however, the junction can be made out clearly.

After crossing the GE junction the tip of the endoscope is slightly angled up and to the right. As the stomach is inflated, a tunnel (Fig. 1.11) becomes apparent. The roof and the base of the tunnel represent the lesser and greater curvature respectively. The endoscope is maintained close to the lesser curvature and gradually pushed forward. The mucosal rugosity in the gastric body turns flat marking the beginning of antrum (Fig. 1.12).

After inspecting the antrum the endoscope is directed towards pylorus. It is a common practice to cross the pylorus, examine D1, D2 and then come back to antrum and complete examination of the remaining stomach. Crossing pylorus is usually a frustrating experience for the beginner. In our practice, we advise the trainee endoscopist to use intravenous Hyoscine Bromide (Buscopan) to knock down gastric peristalsis, keep the pylorus in the center of vision, wait for the ring to open and then attempt to negotiate it. However, after a few endoscopies (usually 8–10) it ceases to be an issue and the endoscopist can cross the pylorus without much difficulty.

All the four walls of D1 are better visualized when the tip of the endoscope is placed at the pyloric ring (transpyloric view). Normally the D1 mucosa is featureless (Fig. 1.14).

The tip of the endoscope is impacted at the apex of D1 and rotated up and right. This maneuver facilitates its entry into D2. As endoscope is withdrawn slightly, its tip slips further down in to D3. The ampulla of Vater can be seen on the medial wall of D2. This is the distal extent of examination for routine UGI endoscopy.

The endoscope is now gradually withdrawn, carefully examining all the four walls of D2. The junction of D1-D2 is better inspected at this stage as the tip of the endoscope has a tendency to slip down during forward examination (Fig. 1.18).

The endoscope is withdrawn into antrum for examination of the remaining part of stomach (Figs 1.19A and B). The tip of the endoscope is flexed up bringing into view the incisura angularis (Fig. 1.19C). In this position, the endoscope is gradually withdrawn maintaining constant insufflation and slight rotation to the left. By this retroflexion or ‘J’ maneuver the entire lesser curvature can be inspected as the fundus is approached (Figs 1.20A to C).

Fluid tends to accumulate in the fundus as this is the most dependant part of the stomach during endoscopy. This ‘fundic pool’ needs to be sucked out to have a clear view of the mucosa. The GE junction can be inspected from a close proximity by withdrawing and rotating the endoscope further (Figs 1.21A and B). Normally, the GE junction should appear snug around the shaft of the endoscope. This completes the examination of the upper GI tract. The tip of the endoscope is rotated to normal position, air in the stomach sucked out and the instrument withdrawn.