Endoscopic retrograde cholangiopancreatography

Endoscopic retrograde cholangiopancreatography is a combination of endoscopy (for detection and cannulation of the ampoule of the Fater's nipple) and X-ray examination after the introduction of a contrast agent into the bile and pancreatic ducts. In addition to receiving images of the biliary tract and pancreas, endoscopic retrograde cholangiopancreatography (ERCP) allows you to examine the upper gastrointestinal tract and periampulular area, and perform a biopsy or perform a surgical procedure (for example, sphincterotomy, removal of the gallstone or stent placement in the bile duct).

To successfully perform endoscopic retrograde cholangiopancreatography and obtain qualitative radiographs, in addition to endoscopes and a set of catheters, an X-ray television and radiocontrast preparations are needed. In most cases, ERCPs are performed using endoscopes with a lateral arrangement of optics. In patients who underwent gastric resection according to the method of Bilrot-II, endoscopes with end or oblique optics should be used to perform endoscopic retrograde cholangiopancreatography.

The requirements for X-ray equipment are quite high. It should provide visual control over the course of the study, the receipt of quality cholangiopancreatograms at various stages of it, the permissible level of exposure to the patient during the study. For endoscopic retrograde cholangiopancreatography, various water-soluble radiocontrast preparations are used: vero- grapes, urographine, angiografins, triombrasts, etc.

Indications for endoscopic retrograde cholangiopancreatography:

1. Chronic diseases of the biliary and pancreatic ducts.
2. Suspicion of the presence of concrements in the ducts.
3. Chronic pancreatitis.
4. Mechanical jaundice of unknown origin.
5. Suspicion of a pancreatoduodenal tumor.

Preparation of patients for endoscopic retrograde cholangiopancreatography.

On the eve appoint sedatives. In the morning the patient comes on an empty stomach. 30 minutes before the test, premedication is performed: intramuscularly 0.5-1 ml of a 0.1% solution of atropine sulfate, methacine or 0.2% solution of platifillin, 1 ml of a 2% solution of promedol, 2-3 ml of a 1% solution of dimedrol. As a narcotic analgesic, the use of morphine-containing drugs (morphine, omnopon), which causes spasm of the sphincter of Oddi, is unacceptable. The key to successful research is a good relaxation of the duodenum. If it is not reached and peristalsis preserved, then the cannulation of the large duodenal papilla (BDS) should not be started. In this case, it is necessary to additionally introduce drugs that depress the motor function of the intestine (buscopan, benzohexonium).

Methods of performing endoscopic retrograde cholangiopancreatography.

Endoscopic retrograde cholangiopancreatography includes the following stages:

1. Revision of the duodenum and large duodenal papilla.
2. Cannulation of the large duodenal papilla and trial introduction of the radiopaque preparation.
3. Contrasting one or both of the flow systems.
4. Radiography.
5. Control over the evacuation of contrast medium.
6. Carrying out of actions for preventive maintenance of complications.

Evaluation of the large duodenal papilla (shape, size, morphological changes, appearance and number of holes) is of great importance both for the diagnosis of duodenal diseases (tumor, papillitis, stenosis of the papilla) and for assessing the anatomical and topographic relationships of the intestine, large duodenal papilla and duct systems. To identify the pathology of the biliary system, the nature of the papilla that is separated from the papilla is important: pus, blood, putty, grains of sand, parasites.

In endoscopic examination of the duodenum, the papilla is detected on the inner wall of the descending part of the intestine when viewed from above. Detailed audit of the papilla is difficult with pronounced peristalsis and narrowing of this department caused by pancreatic head cancer, primary duodenal cancer, enlarged pancreas in chronic pancreatitis. Of great practical importance is the detection of two papillae of the duodenum - large and small. Differentiate them by localization, size and nature of the separated. The large papilla is distal, the height and diameter of its base range from 5 to 10 mm, bile is seen through the opening at the apex. The small papilla settles approximately 2 cm proximally and is closer to the front, its dimensions do not exceed 5 mm, the hole is not contoured, and the detachable one is not visible. Occasionally, both papillae are located side by side. Pancreatography in such cases is safer and more often succeeds, because with the failure of contrasting through the large papilla it can be performed through a small one.

At the beginning of the study, a revision of the duodenum and the large duodenal papilla is performed in the patient's position on the left side. However, in this position the papilla is seen more often in the lateral projection and not only cannulation, but detailed examination of it is difficult, especially in patients who underwent surgery on the bile ducts. Convenient for cannulation and roentgenography, the facial position of the large duodenal papilla can often be obtained only in the position of patients on the stomach. In some cases (in the presence of a diverticulum, in patients after surgery on extrahepatic bile ducts), the removal of the large duodenal papilla in a position convenient for cannulation is possible only in the position on the right side.

Cannulation of the large duodenal papilla and trial introduction of a contrast agent. The success of cannulation of the ampulla of the large duodenal papilla and selective contrasting of the corresponding duct system depends on many factors: good duodenal relaxation, the researcher's experience, the nature of the morphological changes in the papilla, etc. An important factor is the position of the large duodenal papilla. Cannulation can be performed only if it is located in the frontal plane and the end of the endoscope is inserted below the papilla so that it is viewed from below upwards and the ampoule opening is clearly visible. In this position, the direction of the common bile duct will be from the bottom up at an angle of 90 °, and the pancreatic duct from the bottom upwards and forward at an angle of 45 °. The researcher's actions and the effectiveness of selective cannulation are determined by the nature of the fusion of the duct systems and the depth of administration of the cannula. The catheter is pre-filled with a contrast agent to avoid diagnostic errors. To enter it should be not hurrying, precisely having defined an aperture of an ampoule on its characteristic kind and the outflow of a bile. Hasty cannulation can be unsuccessful due to a papilla injury and a spasm of his sphincter.

When the biliary and pancreatic ducts are located separately on the papilla to contrast the first of them, the catheter is inserted into the upper corner of the siphole, and to fill the second one into the lower corner, giving the catheter the above direction. In the ampullar version of the OBD, to reach the mouth of the bile duct, it is necessary to insert the catheter from the bottom upwards by bending the distal end of the endoscope and the movement of the lift. It will slide along the inner surface of the "roof of the large duodenal papilla" and slightly lift it, which is noticeable, especially with the fusion of the bile duct and duodenum at an acute angle and the presence of a long intramural section of the common bile duct. To reach the mouth of the pancreatic duct, the catheter inserted into the ampoule opening is advanced forward by injecting a contrast agent. Using these methods, it is possible either selectively or simultaneously to contrast the biliary and pancreatic ducts.

In patients who underwent surgical intervention (in particular, choledochoduodenostomy), it is often necessary to selectively contrast the ducts not only through the mouth of the large duodenal papilla, but also through the anastomosis opening. Only such a complex study can identify the cause of disease states.

X-ray monitoring of the position of the catheter is possible even with the administration of 0.5-1 ml of contrast medium. With insufficient depth of cannulation (less than 5 mm) and a low (close to the ampoule) block of the duct system with a stone or tumor, cholangiography may fail. With the placement of the cannula in the ampulla of the large duodenal papilla, both duct systems can be contrasted, and with a deep (10-20 mm) introduction, one can be contrasted.

If only the pancreatic duct is contrasted, then you should try to get an image of the bile ducts by injecting a contrast agent while removing the catheter and performing a repeated shallow cannulation (3-5 mm) of the ampulla of the large duodenal papilla, directing the catheter up and to the left. If the cannula is inserted at 10-20 mm, and no contrast medium is visible in the ducts, it means that it rests against the duct wall.

The amount of contrast medium required for cholangiography is different and depends on the size of the bile ducts, the nature of the pathology, the operations carried out, etc. It is usually enough to introduce 20-40 ml of contrast medium. It is withdrawn slowly, and this circumstance allows you to make X-rays in the most convenient projections, which the doctor chooses visually. The concentration of the first portions of contrast medium administered during endoscopic retrograde cholangiopancreatography should not exceed 25-30%. This makes it possible to avoid mistakes in the diagnosis of choledocholithiasis as a result of "blocking" the concrements with highly concentrated contrast preparations.

[1], [2], [3], [4], [5], [6]