What causes cholecystitis?

We all know that the gallbladder is where bile is stored, and it is actually like a small bag. When I eat, my gallbladder releases bile to digest the food. Although the gallbladder only stores bile, it is also prone to problems. Cholecystitis and gallstones are generally more common. Gallstones require surgical treatment, while cholecystitis is slightly better. Why does cholecystitis occur?

Causes

Acute cholecystitis is caused by sudden obstruction or impaction of the cystic duct by stones in the gallbladder. It can also be caused by cystic duct torsion, stenosis, and obstruction by biliary ascariasis or biliary tumors.

In addition, during the aging process, the gallbladder wall gradually becomes thickened or atrophied, and the contractile function is reduced, causing bile stasis, concentration and formation of bile salts; the end of the common bile duct and the sphincter of Oddi become relaxed, making retrograde infection prone to occur; systemic atherosclerosis and increased blood viscosity can aggravate cystic artery ischemia. After obstruction of the cystic duct or gallbladder neck, the stagnant bile in the gallbladder concentrates to form bile salts, which stimulate the gallbladder mucosa and cause chemical cholecystitis (early stage); at the same time, bile retention causes the pressure in the gallbladder to continue to increase. The expanded gallbladder first affects the venous and lymphatic return of the gallbladder wall, and the gallbladder becomes congested and edematous. When the pressure in the gallbladder is >5.39 kPa (55 cmH2O), the blood flow in the gallbladder wall artery is blocked, and the gallbladder suffers ischemic damage. The ischemic gallbladder is prone to secondary bacterial infection, which aggravates the progression of cholecystitis and eventually leads to gallbladder gangrene or perforation. If the cystic duct is obstructed without blood circulation disorder and bacterial infection of the gallbladder wall, gallbladder effusion will develop.

Recent studies have shown that phospholipase A can be released from the damaged gallbladder mucosal epithelium due to bile stasis or stone impaction, hydrolyzing the lecithin in the bile into lysophosphatidylcholine, which in turn changes the integrity of the mucosal epithelial cells and causes acute cholecystitis.

Clinical manifestations

1. Acute cholecystitis

The clinical manifestations of acute calculous cholecystitis are basically the same as those of acute acalculous cholecystitis.

(1) Symptoms

① Pain: Severe pain or colic in the right upper abdomen, mostly acute cholecystitis caused by stones or parasites blocking the neck of the gallbladder; the pain often occurs suddenly, is very severe, or presents a colic-like pain, mostly occurs after eating high-fat foods, and mostly occurs at night; general pain in the right upper abdomen, seen in acute cholecystitis without obstruction of the cystic duct, the pain in the right upper abdomen is generally not severe, mostly persistent bloating, with the progression of gallbladder inflammation, the pain may also worsen, the pain is radiating, the most common radiating sites are the right shoulder and the lower angle of the right scapula, etc., which is caused by gallbladder inflammation stimulating the right phrenic nerve endings and the peripheral nerves of the abdominal wall.

② Nausea and vomiting are the most common symptoms. If nausea and vomiting are persistent or frequent, it may cause dehydration, collapse and electrolyte imbalance, which is more common when stones or ascaris block the gallbladder duct.

③ Chills, chills, and fever. Mild cases often have chills and low fever; severe cases may have chills and high fever, the temperature may reach above 39°C, and mental symptoms such as delirium and delirium may occur.

④ Jaundice is less common. If jaundice occurs, it is generally mild, indicating that the infection has spread to the liver through the lymphatic vessels, causing liver damage, or the inflammation has invaded the common bile duct.

(2) Main physical signs: Abdominal examination may reveal tension, tenderness, rebound pain in the right upper abdomen and mid-upper abdomen, and a positive Murphy sign. In patients with cholecystectomy or pericholecystic abscess, a tender mass or a significantly enlarged gallbladder may be felt in the right upper abdomen. When abdominal tenderness and abdominal muscle tension extend to other areas of the abdomen or the entire abdomen, it indicates gallbladder perforation. Or there is acute peritonitis. 15% to 20% of patients suffer from liver damage due to edema around the cystic duct, gallstone compression and pericholecystitis, or inflammation involving the common bile duct, causing sphincter spasm and edema, leading to bile excretion disorder, and mild jaundice may occur. If the jaundice becomes significantly worse, it may indicate common bile duct obstruction with stones or concurrent common bile duct inflammation. In severe cases, signs of peripheral circulatory failure may occur. Blood pressure is often low and even infectious shock may occur, which is particularly common in severe cases of purulent gangrene.

2. Chronic cholecystitis

(1) Symptoms: persistent dull pain or discomfort in the right upper abdomen; indigestion symptoms such as nausea, belching, acid reflux, abdominal distension and heartburn; pain in the right lower shoulder blade area; symptoms aggravated after eating high-fat or greasy foods; long course of disease, with alternating acute attacks and remissions. Acute attacks are the same as those of acute cholecystitis, and remissions may sometimes be free of any symptoms.

(2) Physical signs: There may be mild tenderness and percussion pain in the gallbladder area, but no rebound tenderness. In cases of cholestasis, an enlarged gallbladder may be felt. In acute attacks, there may be muscle tension in the right upper abdomen, normal body temperature or low fever, and occasionally jaundice. The tenderness point of the gallbladder is at the intersection of the outer edge of the right rectus abdominis and the costal arch, the tenderness point of the thoracic spine is beside the 8th to 10th thoracic vertebrae, and the tenderness point of the right phrenic nerve is between the two lower corners of the sternocleidomastoid muscle on the right side of the neck.