Acute Cholecystitis (Irregular thickness of gall bladder walls)
Acute cholecystitis, or inflammation
of the gallbladder, usually comes about because of a gallstone being lodged in
the cystic duct. The cystic duct is the one that leaves the gallbladder and
connects to the common bile duct. So let’s say this person’s gallbladder’s got
a few gallstones in it, and they go to eat a hamburger, the small intestine
secretes cholecystokinin, sometimes shortened to CCK, into the blood where it
makes its way to the gallbladder, and signals it to squeeze out some bile to
give it a hand with the digestion of that hamburger. The gallbladder contracts and
one of these stones get lodged right in the cystic duct, which blocks bile
flow...now what?
Well, this person probably starts
experiencing some pain, specifically mid-epigastric pain, which happens because
the gallbladder’s trying to squeeze on a blocked duct...and just like if you
squeezed a partly filled balloon with the end blocked off, it physically stretches
out and irritates the nerves in the gallbladder and duct.
This can also lead to nausea and vomiting, which can last for long periods of time. And as the gallbladder squeezes more and more, the stone might get even more stuck, and at this point, the bile, being stuck in the same place, or in a state of stasis, becomes a kind of chemical irritant and causes the mucosa in the walls to start secreting mucus and inflammatory enzymes, which results in some inflammation, distention and pressure buildup. At this point, there might also start to be some bacterial growth, most commonly E coli which is all over the gut, but also Enterococci, Bacteroides fragilis, and Clostridium, which can also be found there.
As it sort of balloons up, the pain
might start to shift to the right upper quadrant, and it’ll be this kind of
dull, achy pain that can even radiate up to the right scapula and shoulders. After
a while, bacteria start invading into the gallbladder wall and eventually
through the wall, causing peritonitis, inflammation of the peritoneum, which
can cause what’s called rebound tenderness, where the pain is brought on when
pressure is actually taken off the belly rather than when it’s applied.
Here’s another physical exam trick,
though. We know that while a patient takes in a deep breath, the diaphragm
pushes down on the gallbladder. You can apply pressure onto the abdomen to keep
the abdominal contents from sliding downward with the abdominal contents
roughly pinned in place, you can ask a patient to take a deep breath and if the
diaphragm pushes down on their gallbladder (which remember s pinned in place),
that will cause pain, forcing the patient to stop breathing in further and
that’d be a positive murphy’s sign which can help with diagnosis. Finally,
since the bacteria have started invading the mucosa and the tissue, the
patient’s immune system kicks in, ramping up the Neutrophils in the blood and
leading to neutrophilic leukocytosis and likely also causing a fever.
At this point, one of two things can
happen, first, the stone could fall out of the cystic duct, which is great, and
then the symptoms and cholecystitis eventually subside, this actually happens
in the majority of cases. The other thing that could happen though is that the
stone doesn’t fall out...And Inadequately filled. that’s the case, pressure can
keep building up, eventually so much so that it starts pushing down on the
blood vessels supplying the gallbladder with blood, which means blood can’t get
to the gallbladder and the tissue starts to get ischemic, leading to gangrenous
cell death, which is cell death due to not having enough of a blood supply. As
the gallbladder walls weaken, they might eventually perforate or rupture. This
causes sharp pain and if left untreated, could allow bacteria to get into the
blood supply and cause sepsis. If it’s allowed to get this far, it’s possible
the patient needs a cholecystectomy or removal of the gallbladder.
For some patients though, if the
stone gets lodged further down in the common bile duct instead of the cystic
ducts, it can start to block the flow of bile from the liver, because remember
that the liver cells help produce bile, right?
If the liver cells keep producing
bile but none of it can go anywhere because of this blockage, bile can start to
back up into the liver, which increases pressure in the bile ducts, and causes
the bile to eventually force its way through the tight junctions between the
cells lining the bile ducts and make its way to the bloodstream, causing an
increase in serum conjugated bilirubin (which is a component of bile) which
leads to jaundice, or yellowed skin.
An important marker that might be
found in someone’s blood that has cholecystitis is alkaline phosphates or ALP,
this is an enzyme found in high amounts in the liver and bile ducts, so when
bile backs up and pressure in the ducts increases, these cells can be damaged
and die, and when they die they release their ALP which can then get into the
blood. A diagnosis can be confirmed by ultrasound which can detect stones as
well as a sonographic Murphy sign which is abdominal tenderness from the pressure
of the ultrasound probe over the gallbladder. Other ultrasound findings include
gallbladder wall thickening, build-up of sludge, and distention of the
gallbladder or bile duct.
A more sensitive study is Cholescintigraphy, sometimes referred to as a HIDA scan. In cholescintigraphy, a radiolabeled marker is used to visualize the biliary system. In the case of acute cholecystitis, the ducts are often blocked and the gallbladder can’t be seen. A blockage of the biliary system can also be seen with Endoscopic Retrograde Cholangiopancreatography or ERCP for short.
In ERCP, an endoscope with a camera
is passed down the mouth and gastrointestinal tract until it reaches the
pancreas. At that point, a contrast dye is injected into the pancreas and the
dye is viewed through a fluoroscope. Another approach is Magnetic Resonance Cholangiopancreatography,
or MRCP, which visualizes the biliary system with the use of a magnetic
resonance machine (MRI). Treatment of acute cholecystitis often includes
supportive measures like intravenous fluids, pain management, and antibiotics. Typically,
the gallbladder is surgically in a procedure called a cholecystectomy; if it’s done
laparoscopically it’s often called a lap chole for short.
All right, as a quick recap … Acute
cholecystitis, is inflammation of the gallbladder that is caused by gallstones
getting lodged in the cystic duct. Often the disease improves on its own once
the stones fall out of the duct. If the stones stay in place there can be a
buildup of pressure that can lead to gallbladder ischemia, and even rupture. The
disease is often diagnosed by ultrasound and treated with cholecystectomy.
