Cholecystocentesis (aspiration sampling of gallbladder bile) can be completed using a percutaneous transhepatic ultrasound-guided approach, by laparoscopic assistance, or during exploratory abdominal surgery. If completed under ultrasonographic surveillance, a transhepatic approach allows adjacent liver tissue to provide a tamponade effect, limiting bile leakage. Whatever approach is used for cholecystocentesis, it is prudent to empty the gallbladder of most bile to limit postcentesis leakage.
The cystic arterial perfusion of the canine and feline gallbladder is oriented in a pinnate distribution pattern with less anastomotic duplicative branching than exists in humans. Consequently, cholecystocentesis in these species done without gross visualization of the gallbladder (ie, under ultrasound guidance) has risk for lacerating a branch of the cystic artery that can lead to regional gallbladder wall necrosis. With this consideration in mind, cholecystocentesis under ultrasound guidance should not be considered baseline data and should only be orchestrated when bileborne infection is a serious diagnostic consideration in a patient not scheduled for surgery or laparoscopy.
Samples of collected bile are used for cytologic evaluation and culture of aerobic and anaerobic bacteria and fungi. It is important to empty the gallbladder to collect bile with particulate debris or sediment in gravitationally dependent regions. It is this material that typically contains bacterial biofilm that will disclose organisms detected by cytologic evaluation and culture.
Complications of cholecystocentesis may include intraperitoneal bile leakage (decreased by using a transhepatic approach), hemorrhage, hemobilia, bacteremia, and a biliary-cardiac reflex (vasovagal reaction). The latter adverse reaction is mediated by the vagal nerve, is more common in cats, and may result in ventilatory arrest, severe bradycardia, and death.
Cholecystocentesis is best done with precautionary insertion of an IV catheter, patient ECG monitoring, on-hand atropine, endotracheal tube, and manual resuscitator.
If a gallbladder mucocele or extrahepatic bile duct obstruction (EHBDO) is suspected, cholecystocentesis is unequivocally contraindicated. It is better to perform a cholecystectomy for gallbladder mucocele and to surgically decompress EHBDO (relieve or bypass the obstruction).