After passing through the pylorus, the endoscope enters the duodenum bulb.
The duodenum bulb should be examined on endoscope insertion rather than during withdrawal as passage of the instrument can cause possible mucosal changes.
After all four quadrants of the bulb are inspected the scope is advanced to the posterior aspect of the bulb; here the duodenum turns right sharply and takes downward turn.
To pass the superior flexure of the duodenum and enter the second part of the duodenum, the instrument is advanced using the dials and shaft torque, usually down and to the right followed by an upward spin of the dial.
The superior flexure of the duodenum is often passed blindly and examined on the way back.
The lower part of the second portion of the duodenum is reached by straightening the endoscope, in other words, pulling the endoscope slowly backward while maintaining the view of the lumen. This maneuver reduces the loop along the greater curvature of the stomach and, paradoxically, advances the endoscope into the distal duodenum.
The duodenum distal to the bulb has distinctive circular rings called valvulae conniventes.
The ampulla of Vater is found in the second portion of the duodenum and examined while withdrawing the endoscope.
After careful examination of the duodenum, pylorus, and antrum, the endoscope is retroflexed to visualize the gastric cardia and fundus.
The endoscope is then returned to a neutral position.
Once the stomach has been fully inspected, and biopsies, if necessary, are obtained, the endoscope is then withdrawn.
Before leaving the stomach, air should be suctioned.
The esophagus is again examined on withdrawal of the endoscope.
The average duration of a diagnostic EGD is 5 to 10 minutes under optimal sedation conditions.
Tissue sampling is obtained from suspicious lesions during EGD, although many gastroenterologists perform routine biopsies from designated sites, as a clinically significant disease may be present in an apparently normal looking mucosa.
Specimens obtained include biopsies, brushings of mucosal surface, and polypectomy.
Specimens are sent for histological, cytological, or microbiologic analysis based upon the type of the sample and clinical situation.