Acute Calculous Cholecystitis

A recent edition of NEJM has a nice review on this common surgical topic...

What proportion of patients with gallstones become symptomatic?

1-4% per year

What proportion of patients with symptomatic cholelithiasis develop cholecystitis?

20%

What is gangrenous cholecystitis?

When the gallbladder wall undergoes necrosis and gangrene.

What is emphysematous cholecystitis?

When gas is visible on imaging in the wall or lumen of the gallbladder... this is indicative of superinfection with gas-forming organisms and may lead to perforation without urgent intervention.

What is Mirizzi's Syndrome?

Obstruction of the common bile duct as a result of extrinsic compression of a stone within the gallbladder or cystic duct.

What is Murphy's Sign?

Arrest of inspiration while palpating the gallbladder during a deep breath.

What are ultrasonographic findings of acute calculous cholecystitis?

Gallstones
Gallbladder wall thickening, greater than 5mm
Pericholecystic fluid
Positive ultrasonographic Murphy's sign

It's also important to assess for choledocholithiasis by evaluating for a common bile duct dilated greater than 7mm or frank CBD stones.

The PPV of stones + Murphy's sign is 92%.
The PPV of stones + GBW thickening is 95%.
The NPV of no stones, and a normal GBW and no Murphy's sign is 95%.

What does a HIDA scan involve?

Hepatic scintigraphy uses an IV injection of technetium-labelled iminodiacetic acid analogues. These are excreted by the liver into bile, and allows visualization of the gallbladder within 30 minutes. An absence of filling of the gallbladder after 60 minutes indicates cystic duct obstruction and is 80-90% sensitive for cholecystitis.

Morphine can improve the specificity of the test by increasing resistance at the sphincter of Oddi. Overall, HIDA has greater specificity and accuracy in comparison to ultrasound, but is usually reserved when the diagnosis of cholecystitis is uncertain.

What is a 'rim sign' on HIDA?

A pericholecystic blush that is seen in 30% of patients with acute cholecystitis and 60% of patients with gangrenous cholecystitis.

What are the Tokyo guidelines?

Diagnostic criteria for Acute Cholecystitis:
Presence of one local sign/symptom, one systemic sign, and any confirmatory finding on an imaging test...
Local signs and symptoms: Murphy's sign, RUQ pain or tenderness, RUQ mass
Systemic signs: Fever, leukocytosis, elevated CRP

According to the Tokyo guidelines, acute cholecystitis can be subdivided into three grades of severity...

What are criteria for Grade 1 - Mild Cholecystitis?

No organ dysfunction
Does not meet criteria for a more severe grade

Early laparoscopic cholecystectomy is recommended.

What are criteria for Grade 2 - Moderate Cholecystitis?

The presence of any of the following:
WBC greater than 18,000
Palpable, tender RUQ mass
Duration greater than 72hrs
Marked local inflammation including pericholecystic abscess, hepatic abscess, gangrenous or emphysematous cholecystitis, or biliary peritonitis

Early or delayed laparoscopic cholecystectomy may be considered depending on the scenario and the surgeon's expertise.

What are criteria for Grade 3 - Severe Cholecystitis?

Organ system dysfunction - hypotension requiring pressors, mental status changes, respiratory insufficiency with PaO2/FiO2 less than 300, oliguria, Cr greater than 2.0, INR greater than 1.5, platelet count less than 100k

Management with antibiotics and percutaneous cholecystostomy tube may be considered, reserving surgery for treatment failures.

What is the optimal timing of cholecystectomy?

For most patients, early cholecystectomy may be favored. 15-20% who had their procedures delayed after the initial attack subsided require intervention before their planned lap chole.

In several studies/meta-analyses, there were no differences in operative time or conversion rates between early and delayed lap chole. However, bile duct injuries in general may be more common in the setting of acute cholecystitis. Postoperative bile duct leaks were more common with early intervention (3%) compared to delayed (0%).

What are the rates of conversion from laparoscopic to open during cholecystectomy for acute cholecystitis?

5-30%

These are greater in acute cholecystitis compared to uncomplicated cholelithiasis, but there is no difference between early and delayed intervention.

When should antibiotics be administered in the setting of cholecystitis?

Per the IDSA, a second-generation cephalosporin or a fluoroquinolone and metronidazole shold be administered in the following scenarios:
WBC greater than 12,500 or Temperature greater than 38.5C AND
Radiographic findings of cholecystitis
Also in elderly, diabetics, or immunocompromised

Patients undergoing cholecystectomy will also get a prophylactic perioperative dose, even if they don't require empiric treatment.

When should percutanous cholecystostomy tubes be used?

Patients with Grade 3/Severe cholecystitis
Septic shock
Poor surgical candidates

Delayed cholecystectomy may be considered at a later time.

Late... SG

References:
Strasberg SM. Acute Calculous Cholecystitis. NEJM 2008; 358: 2804-2811.