Chronic pancreatitis: diagnosis

Diagnosis of chronic pancreatitis presents significant difficulties due to the anatomical location of the pancreas, its close functional connection with other organs of the gastrointestinal tract, the lack of simple and reliable methods of investigation.

The method of coprological examination has not lost its value, especially if it is carried out repeatedly (3-4-5 times or more with small intervals) - in this case the results of the study become more reliable. According to the results of a coprological study, one can judge the state of the digestive process, which largely depends on the function of the pancreas. In pancreatic digestive disorders, the digestion of fats is most disturbed (because it occurs solely due to pancreatic lipase), so in these cases, in the case of coprological examination, first of all, steatorrhea, to a lesser extent - creato and amylorea is found.

Methods for the determination of pancreatic enzymes in blood serum and urine were widely used in practical medicine for diagnosing pancreatic diseases.

The main advantages of these methods are their relative simplicity and laboriousness.

Pancreatic enzymes enter the bloodstream in several ways: first, from the secretory passages and ducts of the gland; second, from the acinar cells to the interstitial fluid and from there to the lymph and blood (the so-called phenomenon of enzyme evasion); thirdly, the absorption of enzymes in the proximal parts of the small intestine.

Increase in the level of enzymes in the blood and urine occurs when there is an obstacle to the outflow of pancreatic secretions and increased pressure in the pancreatic ducts leading to the death of secretory cells. Signs of worsening of chronic pancreatitis can only be a significant increase in the activity of urine amylase - in dozens of times, since an insignificant or moderate increase in this index occurs in other acute diseases of the abdominal cavity. Many authors attach greater importance to the determination of enzymes in the blood serum, more often a study of the level of amylase, less often - trypsin, inhibitor of trypsin and lipase.

It should be borne in mind that the content of amylase in the urine depends on the state of the kidneys, so in doubtful cases, with a violation of kidney function and signs of exacerbation of chronic pancreatitis, the so-called amylazocreatine clearance (or coefficient) is determined.

Of great importance in assessing the state of the pancreas in chronic pancreatitis is the study of an exocrine function, in terms of the degree and nature of the disorder, one can assess the severity of the disease.

To date, the most common method remains duodenal sounding using various stimulants of pancreatic secretion: secretin, pancreosimin or cerulein (tacus). In chronic pancreatitis, bicarbonates and all enzymes are reduced, especially in severe forms.

To test the intrasecretory function of the pancreas at normal fasting blood glucose, a glucose tolerance test is used. With an elevated fasting glucose level, a so-called sugar profile is examined in the blood.

X-ray methods are widely used in the diagnosis of pancreatitis. Occasionally, small patches of calcification in the pancreas region (calcified areas of former necrosis zones, gland duct stones) can usually be detected on survey images of the abdominal cavity.

Duodenography in conditions of artificial hypotension of the duodenum, which allows to detect an increase in the head of the pancreas, changes in BSD, has not lost its diagnostic value to the present day.

Characteristic features of the X-ray picture of the defeat of the head of the pancreas during duodenography:

• Increase the unfolding of the loop of the duodenum,
• The depression on the inner wall of its downward part,
• a sign of Frostberg - deformation of the internal contour of the descending part of the duodenum in the form of a mirror-reflected digit 3,
• two-contouring of the inner wall ("a symptom of the culio) and serration of the internal contour of the duodenum.

In contrast to pancreatitis, the pancreatic head tumor shows an impression on the restricted portion of the inner contour of the duodenum, stiffness and ulceration of its wall.

ERSGG is used for a more detailed study of the region of the BSD, terminal section of the common bile duct and the state of the pancreatic ducts. The method is technically complex and not safe: in 1-2% of cases it gives serious complications, therefore it should be used only for serious indications (differential diagnosis between the tumor, etc.), but it is of great importance, especially when it is necessary to differential diagnosis of chronic pancreatitis and pancreatic cancer glands. There is information in the literature that ERCPG provides reliable information for chronic pancreatitis in 94% of cases, with BSD stenosis - in 75-88,8%, malignant lesions - in 90%.

The signs of chronic pancreatitis, according to the pancreatogram, include the deformation of the contours of the main duct, the unevenness of its lumen with the sites of stenosis and dilatation (clear-cut), changes in the lateral ducts, plugging of small ducts (first and second order) with the formation of cystic enlargements, heterogeneity of the contrasting segments of the gland , violation of the emptying of the main duct (accelerated - less than 2 minutes, slowed down - more than 5 minutes).

Contrast substance in the pancreatic ducts is injected with a duodenofibroscope through a canula in an amount of 3-6 ml. The introduction of a larger volume should be avoided, as this increases the intra-flow pressure, which in turn can exacerbate pancreatitis, until the development of necrosis.

Diagnostically complex cases show selective angiography. Despite considerable informativeness, this method has very limited application in the clinic due to the complexity of the study, mainly for differential diagnostics with neoplastic process and in severe, painful forms of chronic pancreatitis. At present, a number of main angiographic signs of chronic pancreatitis have been identified: uneven narrowing of the arteries and veins lumen, arterial rupture; displacement of arteries and veins, which occurs due to the increase in the size of the gland and the adhesive process that occurs in the surrounding tissues; strengthening or weakening of the vascular pattern of the pancreas; accumulation of contrast agent in the pancreas; increase in part or all of the organ. With cysts of the pancreas on angiograms, a site completely devoid of blood vessels is detected.

Great importance in the diagnosis and differential diagnosis of pancreatitis has CT. With its help, tumor and inflammatory processes in the pancreas are recognized with an accuracy of up to 85%. In chronic pancreatitis, the sensitivity of CT is 74%.

In recent years, in the clinical practice widely used ultrasound of the pancreas. It should be emphasized that this is one of the few methods that is not laborious and easy for the patient. The diagnosis of chronic pancreatitis, established on the basis of ultrasound, coincides with the final clinical in 60-85% of cases.

The main ultrasound signs of the pathology of the pancreas are changes in the structure, while echoes can be low (due to the edema of the parenchyma) or increased (due to fibrosis of the parenchyma) intensity; change in size (limited or diffuse); a contour change that can be blurred (due to inflammation, swelling), uneven, jagged (with chronic inflammation, swelling), outlined (with a cyst, abscess, tumor).

Instrumental research methods are of great importance in determining the nature and extent of pancreatic disease. Each of them has its own diagnostic capabilities and gives certain information. Therefore, the examination of the patient should be based on the integrated application of these methods.

It is necessary to start diagnostics with simple and easy-to-use studies, such as ultrasound, duodenography under conditions of artificial hypotension. It should be borne in mind that ultrasound and CT practically provide identical information. With a clear ultrasound imaging of the pancreas, CT is impractical. In unclear cases with suspicion of a volume lesion of the BSD and the terminal section of the common bile duct, ERCPH and selective angiography should be included in the examination plan.

Laboratory examination

Compulsory methods of examination

• The general analysis of a blood: increase in an ESR, a leukocytosis with shift to the left at an exacerbation.
• The general analysis of urine: presence of bilirubin, absence of urobilin in pseudotumorose (icteric) variant; an increase in α-amylase during exacerbation, a decrease in sclerosing form with an impaired exocrine function (norm 28-160 mgDch-ml).
• Biochemical analysis of blood: with exacerbation, an increase in the content of a-amylase (norm 16-30 g / hl), lipase (norm 22-193 E / L), trypsin (10-60 μg / l), γ-globulins, sialic acids , seromucoid, bilirubin due to the conjugated fraction in icteric form; glucose in violation of the incretory function (sclerosing form); a decrease in the level of albumin in the long-term course of the sclerosing form.
• Examination of the exocrine function of the pancreas:

Determination of enzymes (lipase, a-amylase, trypsin), bicarbonate alkalinity in duodenal contents before and after administration to the 12-colon of 30 ml of 0.5% hydrochloric acid solution: 6 servings are collected every 10 minutes, normally after administration of hydrochloric acid in the first two servings of juice, the concentration of enzymes is reduced, from 3-4 servings increases, in 6 - reaches the initial or even exceeds it. In chronic pancreatitis with exocrine insufficiency, there is a marked decrease in enzymes and bicarbonate alkalinity in all portions. The test is performed using a two-channel gastroduodenal probe with separate aspiration of gastric and duodenal contents;

Lasus test: urine test for hyperaminoaciduria. With exocrine insufficiency of the pancreas, the physiological ratio of the amino acids that are absorbed in the small intestine is disturbed, which is necessary for their utilization in the liver; as a result, amino acids are not digested and in elevated amounts are excreted in the urine. The sample is performed as follows - 30 ml of 2% zinc sulfate solution is added to 30 ml of urine and after 24 hours urine microscopy reveals polymorphic crystals of black-gray-purple or yellowish color in the urinary deposit;

Glycoamylasemic test: determination of the level of a-amylase in the blood before and after 3 hours after loading 50 g glucose. An increase in the concentration of a-amylase in the blood more than 25% indicates a pathology of the pancreas;

Prozerin test: determination of the content of urinary a-amylase (norm 28-160 g / chl) before administration of 1 ml of 0.06% solution of proserin and every 0.5 hours for two hours after administration. The level of urine a-amylase after the introduction of prosirin increases 1.6-1.8 times and after 2 hours it returns to the initial level. With chronic pancreatitis of mild and moderate degree, the initial level of a-amylase is normal, after the addition of prozerin it rises more than 2-fold and after 2 hours it does not return to normal. When the relapsing form is aggravated, the initial concentration of a-amylase is higher than normal, after the addition of prozerin it rises even more and after 2 hours it does not return to normal. With sclerosing form, the initial level of α-amylase is below normal and after stimulation it does not increase.

Secretin-pancreosimine test: determination of bicarbonate alkalinity and concentration of enzymes a-amylase, lipase and trypsin in basaltic duodenal contents, and then after intravenous injection of secretin 1.5 dl / kg body weight (it stimulates the release of the liquid part of pancreatic juice rich in bicarbonate; after administration, the duodenal contents are removed within 30 minutes); and pancreosimin at a dose of 1.5 U / kg of body weight (it stimulates the secretion of pancreatic enzymes) and receives duodenal contents for 20 minutes. After the introduction of secretin, the amount of bicarbonate increases in norm in comparison with basal by 10-11 times, the number of enzymes in 20 minutes (the debit) increases after the administration of pancreosimin as follows: a-amylase 6-9 times, lipase 4-5 times, trypsin in 7-8 times. In the initial phase of chronic pancreatitis, there is an increase in indicators (a hypersecretory type), subsequently, as a rule, a decrease (a hypoxecretory type).

• Study of the incremental function of the pancreas - a test for glucose tolerance: tolerance is reduced in the long course of the disease, especially with the sclerosing variant.
• Coprocytotramma: a greasy texture, undigested fiber, creatorrhea, steatorrhea, amylorrhoea with expressed exocrine insufficiency.

Some doctors suggest using the iodolipolide test as a screening test for chronic pancreatitis . It is based on the ability of lipase to break down the iodolipol, resulting in the release of iodide, which is excreted in the urine. The test is conducted as follows. The patient urinates at 6 o'clock in the morning, then takes in 5 ml of a 30% iodolipol solution, drinking 100 ml of water. Next, 4 portions of urine are collected: after 1, 1.5, 2 and 2.5 hours. 5 ml of urine are taken from each portion, 1 ml of 10 % solution of the solution of sulfuric acid is oxidized, 1 ml of a 2% solution of sodium nitrate and chloroform is added and shaken carefully. The intensity and speed of appearance of red color (free iodine) in chloroform serve as indices of lipase activity, are marked semi-quantitatively with 1-4 pluses. With normal activity of pancreatic lipase, the following results are observed: 1 serving + or ±; 2 portion ++ or +; 3 portion +++ or ++; 4 portion ++++ or +++.

Insufficient activity of lipase and, consequently, insufficient function of the pancreas is manifested by a significant decrease in the intensity of the color.

• Pancreatosimine test. In healthy people, when stimulating the exocrine function of the pancreas, the level of pancreatic enzymes in the serum does not exceed the upper limit of the norm. In the pathology of the pancreas, conditions are created for the excessive penetration of enzymes into the blood, so the increase in its activity and the formation of a large number of enzymes cause an increase in the level of fermentemia. This is the basis of the serum pancreosimin test. In the morning on an empty stomach, 10 ml of blood is taken from the vein, pancreosimin is administered through the same needle at a rate of 2 VD per 1 kg of body weight at a concentration of 5 units per ml. The rate of drug administration is 20 ml for 5 min. After pancreosimin, immediately begin to inject secretin at a rate of 2 units per 1 kg of body weight at the same rate. 1 and 2 hours after the stimulation, 10 ml of blood is taken from the vein from the patient. In the three blood portions obtained, trypsin, its inhibitor, lipase, amylase is determined.

The increase in the level of fermentemia compared with the original by 40% is considered a positive test result.

Instrumental data

Ultrasound examination of the pancreas . Characteristic signs of chronic pancreatitis are:

• heterogeneity of pancreatic structure with areas of increased echogenicity;
• calcification of the gland and stones of the pancreatic duct;
• unevenly expanded virsung duct;
• enlargement and consolidation of the head of the pancreas with pseudotumorous disease;
• uneven contour of the pancreas;
• increase / decrease in the size of the pancreas;
• diffuse increase in echogenicity of the pancreas;
• restriction of the displacement of the gland during breathing, its rigidity during palpation;
• morbidity with echoscopically controlled palpation in the projection of the gland;
• no changes in the ultrasound of the pancreas in the early stages of chronic pancreatitis.

X-ray examination (duodenography in conditions of hypotension) allows to detect the following characteristic signs:

• calcification of the pancreas on an overview radiograph (a sign of chronic calcific pancreatitis);
• the unfolding of the arch of the duodenum or its stenosis (by increasing the head of the pancreas);
• depression on the internal wall of the descending part of the duodenum; a sign of Frostberg - deformation of the internal contour of the descending part of the duodenum in the form of a mirror-reflected digit 3; double-contour of the posterior wall ("symptom of the wings"), serration of the inner contour of the duodenum;
• an increase in the retro-gastric space (indicating an increase in the size of the body of the pancreas);
• reflux of contrast in the pancreatic duct (duodenography under compression).

Endoscopic retrograde pancreatocholangiography reveals the following signs of chronic pancreatitis:

• uneven expansion of the Virsung duct, its broken nature, deformation of the contour;
• stones in the duct of the pancreas;
• heterogeneity of contrasting segments of the gland;
• violation of the emptying of the main duct of the pancreas.

Computer and magnetic resonance tomography of the pancreas reveal a decrease or increase in size, changes in gland density, calcification, pseudocysts.

Radioisotope scanning of the pancreas using methionine, labeled with selenium-75 - is characterized by an increase or decrease in its dimensions, diffuse uneven accumulation of the isotope.

Differential diagnosis of chronic pancreatitis

Peptic ulcer disease: a characteristic anamnesis, the connection of pain with food intake, seasonality of exacerbations, absence of diarrhea.

Gallstone disease and cholecystitis: painful syndrome is characteristic in the right hypochondrium with irradiation to the right and up, in the back, under the right scapula, tenderness in palpation in the right hypochondrium, symptoms of Kera, Ortner, Murphy. Conduct ultrasound and cholecystography to detect concrements.

Inflammatory diseases of the small and large intestine: characterized by the absence of pronounced violations of the exo-and endocrine functions of the pancreas. For differential diagnosis, radiographic, endoscopic examinations of thick and, according to indications, small intestine, bacteriological study of feces are used.

Abdominal ischemic syndrome: systolic murmur in the epigastric region and change or obstruction of the celiac trunk or superior mesenteric artery according to aortograms.

Pancreatic cancer: the corresponding changes are typical for ultrasound, selective angiography, CT, laparoscopy with biopsy.

Indications for consultation of other specialists

• Surgeon: if necessary, surgical treatment.
• Oncologist: if pancreatic cancer is detected.
• Endocrinologist: with the development of endocrine insufficiency and diabetes mellitus.

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