What Is a Pancreatic Pseudocyst?

Pancreatic pseudocysts are mostly secondary to acute and chronic pancreatitis and pancreatic damage. The accumulation of local tissue necrosis and disintegration caused by extravasation of blood, pancreatic juice, and the pancreas itself cannot be absorbed and forms. Composition, there is no pancreatic epithelial liner in the capsule, so it is called a pancreatic pseudocyst.

Basic Information

English name: pancreatic pseudocyst
Visiting department: Internal medicine
Common locations: pancreas
Common causes: Acute pancreatic pseudocyst: secondary to acute pancreatitis and pancreatic injury; chronic pancreatitis: gallstones, alcoholism, and injury

Common symptoms: Acute: fever, upper abdominal tenderness and tenderness, lump, bloating, gastrointestinal dysfunction; chronic: low back pain, fat digestive dysfunction, bleeding, etc.

Causes of pancreatic pseudocysts

Acute pancreatic pseudocyst is a cyst formed by the acute accumulation of cysts. It is mostly secondary to acute pancreatitis and pancreatic injury. The cause of acute pancreatitis varies with different countries and regions. Domestically, acute pancreatitis induced by gallstones accounts for the majority, and alcoholism causes less, while alcoholic acute pancreatitis in Europe and the United States accounts for the majority, with gallstones accounting for only 10%.

Chronic pancreatic pseudocysts are caused by ruptured pancreatic duct obstruction based on chronic pancreatitis. The etiology of chronic pancreatitis is mainly gallstones, alcoholism and injury, and it is rare in hyperlipidemia and hypercalcemia with primary hyperparathyroidism.

Clinical manifestations of pancreatic pseudocyst

The clinical manifestations of pancreatic pseudocysts are mainly based on the stage of acute or chronic pancreatitis. Acute cysts are characterized by fever, upper abdominal tenderness and tenderness, lumps, bloating, and gastrointestinal dysfunction; serious complications can occur.

Chronic pancreatic pseudocysts mostly occur on the basis of chronic recurrent pancreatitis. When the cysts are not very large, they are mainly manifested by the symptoms of chronic pancreatitis, such as upper abdominal and lower back pain, fat digestive dysfunction, and diabetes. Splenomegaly and upper gastrointestinal bleeding are the characteristics of this disease.

Pancreatic pseudocysts are divided into 3 types:

1. Type 1 after necrosis

Secondary to acute pancreatitis, the cyst wall is mature or immature, the cyst and the bile duct rarely communicate, and ERCP shows no abnormality of the pancreatic duct.

2. Type II after necrosis

Seen in the acute episode of chronic pancreatitis, the cystic wall is mature or immature, and is often connected with the pancreatic duct. ERCP showed signs of chronic pancreatitis, but no pancreatic duct obstruction.

3. Retention type III

With chronic pancreatitis, cystic wall maturation and pancreatic duct communication, ERCP showed obvious narrowing of the pancreatic duct. This classification helps to choose the timing and method of treatment.

Pancreatic pseudocyst

Laboratory inspection

Approximately half of the patients have increased serum amylase and increased white blood cell counts, and bilirubin can increase during biliary obstruction. If the serum amylase in patients with acute pancreatitis continues to increase for more than 3 weeks, half of the patients may be complicated by pseudocysts.

2. Other auxiliary inspections

(1) X-ray examination including plain film and gastrointestinal barium meal radiography. Abdominal plain film shows the displacement of air bubbles in the stomach and colon. Due to calcification caused by pancreatitis, patchy calcifications may occasionally appear in the pancreas, and the wall of the capsule shows a dense, linear shadow. Gastrointestinal barium meal imaging Barium meal, barium enema, or both methods can be used due to different circumstances.

(2) B-ultrasound The accuracy rate of this method is as high as 95% to 99%. It can not only determine the size and position of the cyst but also identify the nature of the cyst, the thickness of the cyst wall, the clarity of the cyst, and the presence or absence of atrial septum. Therefore, it should be used as the first inspection method for pancreatic cysts. Dynamic observation can be performed multiple times to guide the treatment and determine the timing and method of surgery.

(3) CT examination This method can not only display the location and size of the cyst, but also determine its properties, which is helpful for the differentiation of pancreatic pseudocysts from pancreatic abscesses and pancreatic cystic tumors. For patients with more gas in the cyst or obese patients, especially for cysts with a diameter <5cm, which is difficult to detect by B ultrasound, a better imaging result can be obtained.

(4) ERCP examination can show pancreatic duct stenosis in chronic pancreatitis, and some cysts can communicate with the pancreatic duct. However, this inspection has the risk of inducing infection. In recent years, it is not recommended to apply, and it is generally only arranged before surgery. In the case of antibiotics, it provides a basis for choosing a surgical method.

(5) Percutaneous fine needle aspiration cytology is used to identify cystic fluid. There are still differences on this inspection method.

Pancreatic pseudocyst

Clinically encountered patients with acute and chronic pancreatitis or epigastric injury, epigastric pain, fullness, and mass with gastrointestinal dysfunction. During the physical examination, they can touch the round or oval mass of the upper abdomen, and the border Unclear, fixed, deep tenderness with cystic sensation, the possibility of pancreatic cysts should be thought of, and diagnosis can be made by gastrointestinal angiography and B-ultrasound.

Differential diagnosis of pancreatic pseudocyst

Pancreatic pseudocysts must be distinguished from pancreatic abscesses and acute pancreatic cellulitis. Patients with abscesses often show signs of infection. Occasionally, pseudocysts can manifest as weight loss, jaundice, and palpable enlarged gallbladder. Pancreatic cancer is often considered first. A CT scan showed that the lesion was fluid, suggesting that a correct diagnosis could be made for a pancreatic cyst. Proliferative cysts, as well as pancreatic cystadenoma or cystadenocarcinoma, account for about 5% of pancreatic cystic lesions, and should be distinguished from pancreatic pseudocysts before surgery. The exact differential diagnosis is mainly determined by biopsy.

Complications of pancreatic pseudocyst

The complications of pancreatic pseudocysts are more common in acute pancreatic pseudocysts.

Intracapsular hemorrhage

Many thick blood vessels around the pancreas and upper abdomen often form part of the sac wall, such as left gastric arteriovenous vein, right gastric arteriovenous vein, spleen arteriovenous vein, etc. The blood vessel wall is activated by pancreatic enzymes and infection, and patients with sudden rupture and bleeding may Sudden and abrupt abdominal pain appears suddenly, abdomen mass increases sharply, and there are irritation signs, often showing symptoms of internal bleeding, and soon enter a state of shock.

Cyst rupture

Abdominal masses suddenly disappear after the cyst is ruptured. If the cystic fluid enters the abdominal cavity, continuous severe abdominal pain can cause acute diffuse peritonitis. External drainage of the cyst is required for emergency diagnosis.

3. Infection

Abdominal pain, fever, and increased white blood cell counts are common signs of cyst infection, and secondary acute pancreatic pseudocysts are difficult to distinguish from acute severe pancreatitis and necrosis combined with infection. Especially within 2 weeks, treatment should be drained immediately.

4. The cyst's pressure on the surroundings

Giant cysts compress the stomach and duodenum or colon. Gastrointestinal obstruction can occur. Obstructive jaundice can occur when the common bile duct is compressed. Vein compression or venous thrombosis is the most common, followed by the portal vein and superior mesenteric vein. It can form high pressure in the stomach and spleen area, extrahepatic portal vein pressure, or duodenal varicosity and major gastrointestinal bleeding.

Pancreatic pseudocysts treatment

Non-surgical treatment

Early detection of pancreatic pseudocysts should be treated clinically with conservative methods.

(1) Medical treatment If accompanied by acute pancreatitis, the pancreas should be in a resting state to reduce the extravasation of pancreatic juice to control the development of cysts. Methods include strict fasting for about 3 weeks, and the use of H ₂ receptor antagonists and somatostatin to reduce the secretion of secretin and cholin-trypsin in the gastrointestinal decompression to keep the pancreatic secretion function at rest; Water and electrolyte balance, intravenous nutrition support, etc. Early application of antibiotics that can pass the blood-pancreatic barrier, such as quinolones and antibiotics such as chlorine, lincomycin (jiemycin), to prevent and treat pancreatic infections. In the middle and late stages, broad-spectrum antibiotics such as third-generation cephalosporins and aminoglycosides are used.

(2) The rate of recurrence of simple fine needle aspiration is as high as 50% to 98%. Repeated puncture not only causes pain to patients, but also easily leads to retrograde infection.

(3) Percutaneous catheter drainage Indications For acute pancreatic pseudocysts, confirmed by B-mode ultrasonography as unisexuality, the following situations occur: rapid cyst enlargement may rupture; cysts with infection; huge cysts compressing surrounding organs Caused by dysfunction. Method Usually under the guidance of B ultrasound or CT, generally use> 8 FJ-type tube, rinse with antibiotic saline 1 to 2 times a day. Indications for extubation: cyst collapse; 24-hour drainage <10ml; cystography confirmed that the catheter was unobstructed and the cyst was not in communication with the pancreatic duct or digestive tract. Because long-term catheterization can compress the digestive tract and easily cause internal fistula, and complications such as retrograde infection catheter breakage can occur. Even if the cyst is in communication with the pancreatic duct or digestive tract or the intra-saccular multiple drainage is not smooth, it should be cured for 6 weeks. Abandon the catheter and switch to intraoperative drainage.

(4) Endoscopic treatment Endoscopic cyst gastrointestinal anastomosis and endoscopic cyst duodenal anastomosis can be performed. For those who have symptoms of gastrointestinal compression, the pancreatic head cysts located beside the duodenum with a diameter of more than 6 cm are not suitable for surgery. It is safer to choose endoscopic treatment. This method is particularly suitable for older people who cannot tolerate surgery.

2. Surgical treatment

(1) Surgical resection The pancreatic pseudocyst cyst wall is composed of inflammatory fibrous connective tissue, which is closely adhered to the surrounding organs. Reluctant separation may lead to bleeding and damage to surrounding organs. The indications for resection are limited to: chronic pancreatitis- induced communication Chronic pancreatic pseudocyst with sexual and pancreatic duct obstruction. The external drainage of such cysts is often ineffective and the internal drainage has a high recurrence rate. Multi-chamber pancreatic pseudocysts in the tail of the pancreas have poor internal and external drainage. For cysts on the head of the pancreas, tumor cysts cannot be ruled out or treatment of chronic pancreas Pancreaticoduodenectomy can be performed only when there are inflammatory factors; pancreatic pseudocysts at the tail of the pancreas can be removed at the tail of the pancreas. If the cyst is tightly separated from the spleen, forcible separation can lead to major bleeding, especially for adults over 30 years of age. The spleen is excised together.

(2) Internal drainage Any cyst with a diameter> cm and a mature cyst wall. Generally, the time is set to 6 weeks, because the cyst wall is thick and difficult to resolve naturally over 6 weeks. CT scan is of great value in judging whether the cyst wall is mature. Chronic pancreatic pseudocysts are especially connected with the pancreatic duct with pancreatic duct stricture Or, consider this technique.

(3) Surgical anastomosis Duodenal anastomosis of cysts Duodenal anastomosis of cysts is prone to serious complications such as bleeding, biliary fistula, and pancreatic fistula. Therefore, care must be taken in the choice and operation must be careful. Gastric anastomosis has the advantages of strong peristalsis of the stomach, which helps empty the cyst and accelerate the collapse of the cyst wall. At the same time, the content of the stomach into the cyst cavity can inhibit the activities of various enzymes in the pancreas and prevent the enzyme from eroding the cyst wall. Disadvantages It is the undigested stomach content that enters the cystic cavity, causing the cystic cavity to be infected with alkaline pancreatic enzymes to enter the stomach to stimulate the gastric antrum and cause a large amount of gastrin secretion, which can induce the occurrence of ulcer disease.

(4) External drainage has many shortcomings. It is easy to corrode the skin, and it will lose a lot of water, electrolyte, protein and pancreatic juice. Postoperative treatment is difficult. The cyst recurrence rate is 21% -28%. All the disadvantages of drainage are the need to change the dressing every day. It is easy to retrograde infection, the incision is difficult to heal, and pancreatic fistula is very easy to form. Therefore, it is only used for patients with very poor general conditions, the capsular wall is close to the abdominal wall, and the capsular wall is very thin. Mushroom or T-tube drainage for cysts After finding the cyst, cut and dispose of the contents of the cyst, place a T-tube or mushroom drainage tube, and close the cyst incision intermittently. The drainage tube passed through the omentum, and another puncture hole led out of the body. This method can avoid skin corrosion and does not require daily dressing changes, can reduce retrograde infections, and will not affect incision healing.

(5) In recent years, one-stage drainage of cysts inside and outside the stomach and one-stage drainage of cysts and jejunum Roux-en-Y have been achieved. This method has both the advantages and disadvantages of internal drainage and external drainage.

Prognosis of pancreatic pseudocyst

The recurrence rate of pancreatic pseudocysts is 10%, and the recurrence of external drainage is relatively high. Severe postoperative bleeding is rare, mainly seen in gastric cyst anastomosis. In short, pseudocyst surgery has fast curative effect and few complications. Many patients with chronic pain manifestation mainly due to chronic pancreatitis.