Biliary disorders are among the most common reasons for patients with acute abdominal pain to seek medical care.
Acute cholecystitis typically is the first diagnosis considered in patients presenting with right upper quadrant pain.
Approximately 90-95% of acute cholecystitis are related to gallstone impactation in the cystic duct or gallbladder neck,
resulting in outflow obstruction of the gallbladder and associated luminal distention.
Increasing gallbladder distention and subsequent intraluminal pressure leads to irritation of the gallbladder mucosa and venous and lymphatic congestion,
leading to the release of several inflammatory mediators and progressive gallbladder wall inflammation.[1,2] Acalculous cholecystitis,
which accounts for 5-10% of acute cholecystitis,
typically occurs in critically ill patients or patients with prolonged illness and is associated with higher mortality and morbidity rates.[2] Empyema of the gallbladder or suppurative cholecystitis occurs when the inflamed and distended gallbladder is filled with pus.
Typically occurs in diabetic patients and may behave like an intra-abdominal abscess.[3] If left untreated,
acute cholecystitis may complicate with necrosis,
gangrene,
and perforation.
Gangrenous cholecystitis is a severe form of acute cholecystitis when there is progression to ischemic necrosis of the gallbladder wall,
intramural hemorrhage or abscess.
It can complicate with perforation.
Gangrenous cholecystitis is more common in men,
patients of advanced age,
and those with coexisting cardiovascular disease and diabetes.[1,3]
Hemorrhagic cholecystitis is a rare complication of acute cholecystitis that occurs in the setting of gangrenous cholecystitis.
Transmural inflammation causes mucosal necrosis and ulceration,
resulting in hemorrhage into the gallbladder lumen.
Prompt diagnosis is essential because of the associated high mortality.[1]
Emphysematous cholecystitis is a rare,
life threatening,
and rapidly progressive complication of acute cholecystitis that results from cystic artery compromise and secondary infection of the gallbladder wall by gas-forming organisms such as Clostridium perfringens,
Escherichia coli,
and Bacilis fragilis.
This complication occurs with higher frequency in men,
patients with diabetes and older patients.
It is associated with a five times greater risk of perforation.[2]
Gangrenous,
hemorrhagic and emphysematous cholecystitis may progress to gallbladder perforation. The most common mechanism of gallbladder perforation involves cystic duct obstruction leading to gallbladder distention,
followed by vascular compromise,
ischemia,
necrosis,
and ultimately perforation.
The fundus is the most frequent site of perforation because of the relatively poor blood supply in this area.[2,3] Gallbladder perforation is subclassified into three types: acute free perforation into the peritoneal cavity,
resulting in generalized peritonitis,
which is associated with the highest mortality rate; subacute perforation with pericholecystic abscess and localized peritonitis,
which is the most common; and chronic perforation which may complicate with cholecystoenteric fistula formation and possible progression to gallstone ileus.[1]
Gallstone ileus is a rare complication of cholelithiasis and an infrequent cause of mechanical bowel obstruction.
It usually occurs in patients with subacute or chronic cholecystitis resulting in perforation of the gallbladder.
Long-standing gallbladder obstruction can lead to gallstone erosion into the small bowel,
usually through a cholecystoenteric fistula.[2] Gallstone ileus may occur,
however,
in the absence of a fistula,
following the passage of a large stone after endoscopic sphincterotomy or cholecystectomy.[1,2]
Conditions affecting and obstructing the common bile duct may also be the cause for right upper quadrant abdominal pain.
Biliary colic frequently results from obstruction of the bile duct caused by impaction of a calculus.
Most biliary stones originate from the gallbladder rather than being formed de novo in the common bile duct.
They are asymptomatic unless they cause obstruction,
which occurs typically at the ampulla of Vater.[2]
Acute cholangitis results from a combination of biliary stasis (with partial or complete obstruction of the biliary tract) and bacterial colonization of the bile ducts.[4] The most common bacteria isolated in infected bile without prior instrumentation are Escherichia coli,
Klebsiella pneumoniae,
Enterococcus faecalis and Streptococcus spp.
Acute suppurative cholangitis refers to the presence of pus in the biliary tract,
a condition that can lead to increased intraluminal pressure and precipitate biliary sepsis,
which,
if untreated,
is associated high morbidity and mortality.[2]
Tumoral biliary obstruction is out of the scope of this work and will not be discussed.