This is caused by a blockage in the cystic duct or neck of the gallbladder (95% of cases are gallstones or gallstone precursor ‘sludge’)
It is unlikely to be infection, and more likely to be local inflammation. You can also get associated peritonitis.
The obstruction causes an increase in mucus secretions from the gallbladder, which causes gallbladder distension, and may affect the blood supply to the gallbladder.
The initial event in cholecystitis is often an obstruction to gallbladder emptying. In 95% of cases, a gallstone is the cause! It is different to biliary colic because it is not a problem in the bile duct, but a problem in the gallbladder or the cystic duct.
Occasionally the obstruction is due to mucus (e.g. CF), worms or a tumour.
The obstruction will cause an increase in gallbladder secretion which leads to distension of the bile ducts. This has two effects; it can obstruct the blood flow to the gallbladder, as well as initiating an inflammatory response to the bile retained in the gallbladder. This can lead to mucosal damage, which in turn leads to the release of phospholipase, which converts lecithin into lysolecitihin, which is a very potent toxin.
Infection will occur in about 50% of patients by the time of surgery.
- Similar to those of biliary colic, and often differentiation is difficult. Cholecystitis often results in a more prolonged pain with a fever and leukocytosis.
- ↑WCC – in cholecystitis, but not in biliary colic.
- Murphy’s Sign. There will be RUQ pain that is usually worse on inspiration. Murphy’s sign is where you would put your hand under the patient’s ribs and ask them to breathe in. As they do so, their gallbladder will be forced down against your hand, and it will cause them a lot of pain!
- Only a positive result if the sign is negative in the LUQ!
- Jaundice (in <10% of patients)
- The pain is more likely to radiate to the shoulder tip in this than is other biliary conditions because the radiation is caused by irritation of the diaphragm and this is more likely in cholecystitis.
- Full blood count – ↑ESR, ↑CRP, ↑WCC
- Serum amylase – ↑- acute pancreatitis may be present as a complication of gallstones.
- Serum bilirubin, alkaline phosphatase and amino transferase may all be slightly raised.
- The bile duct will often be dilated to >8mm
USS – may detect:
- Gallbladder wall thickening
- Dilated common bile duct (>6mm)
- Nil By Mouth
- Bed rest
- Cefuroxime – 1.5mg/8h IV
- Metronidazole – add if patient is particularly ill
- Analgesics; usually diclofenac (NSAID), with pethidine (fast acting opioid) in more severe cases.
- IV fluids
Most cases will resolve with this sort of basic management, however there is a risk of perforation (and thus peritonitis) as well as empyema.
Consider Surgery - Young, fit patients may be suitable for:
- Immediate Cholecystectomy – performed laparoscopically. Mortality <1%. Should be performed within 48 hours of presentation if patient is able to tolerate surgery.
- Delayed Cholecystectomy – may be suitable for other patients, and should be performed 6-12 weeks after the initial presentation. However – recurrence occurs in 18% of patients, and complications occur in 15%, so immediate laparscopic cholecystectomy is the treatment of choice.
- Cholecystostomy – may be suitable for some (e.g. old/frail), and still allows for future cholecystectomy.
Bacterial infection and subsequent empyema
- Bacterial Infection – is a consequence and not a cause of cholecystitis.
- Empyema - this is a collection of pus in a bodily cavity. It is different from an abscess, which is a collection of pus in a newly formed body cavity (i.e. not a normally naturally occurring one).
In some patients a state of chronic cholecystitis can exist. Typically there might be:
- Vague abdominal symptoms: Nausea, pain, distension, flatulence, fat intolerance, IBS
- Sometimes associated with GI malignancy (stomach, pancreas, gallbladder, colon)
- USS – look for evidence of gallstones, and check common bile duct diameter
- MRCP – Magnetic Resonance Cholangiopancreatography – may also be used to check for stones. In this procedure, MRI scanning is used to visualise the biliary tree. It is much less invasive than ERCP – which requires the insertion of dye into the biliary tree via OGD. ERCP has obvious therapeutic advantages that MRCP does not. MRCP is used to supplement USS.
- ERCP – usually performed to remove any stones from the common bile duct and perform sphincterotomy before cholecystectomy
- Cholecystectomy – performed in troubling cases