Evidence-Based Medicine: Ultrasound-Guided Percutaneous Cholecystocentesis in the Cat

Cholangitis is a common cause of hepatobiliary disease in the cat. Feline cholangitis is characterized as neutrophilic (acute or chronic), lymphocytic, or caused by liver flukes. The neutrophilic form is caused by bacterial infection of the biliary system, and identification of the specific bacterial agent guides treatment. Bile is the sample of choice for cytology and bacterial culture in these cases, and percutaneous ultrasound-guided cholecystocentesis is used to obtain that sample. This review covers the literature that provides evidence for safety and usefulness of percutaneous ultrasound-guided cholecystocentesis as part of the diagnostic work-up of cats suspected of having hepatobiliary disease.

Association between Gallbladder Ultrasound Findings and Bacterial Culture of Bile in 70 Cats and 202 Dogs

Background

Bacterial cholecystitis often is diagnosed by combination of gallbladder ultrasound (US) findings and positive results of bile culture. The value of gallbladder US in determining the likelihood of bile bacterial infection in cats and dogs with suspected biliary disease is unknown.

Hypothesis/Objectives

To determine the value of gallbladder US in predicting bile bacterial culture results, identify most common bacterial isolates from bile, and describe complications after cholecystocentesis in cats and dogs with suspected hepatobiliary disease.

Animals

Cats (70) and dogs (202) that underwent an abdominal US and submission of bile for culture were included in the study.

Methods

A cross‐sectional study design was used to determine the association of gallbladder US abnormalities and the results of bile cultures, and complications of cholecystocentesis.

Results

Abnormal gallbladder US had high sensitivity (96%) but low specificity (49%) in cats with positive and negative results of bile bacterial culture, respectively. Cats with normal gallbladder US findings were unlikely to have positive bile bacterial culture (negative predictive value of 96%). Gallbladder US had lower sensitivity (81%), specificity (31%), positive predictive value (20%), and negative predictive value (88%) in dogs. The most common bacterial isolates were of enteric origin, the prevalence being higher in cats. Incidence of complications after cholecystocentesis was 3.4%.

Conclusions and clinical importance

Gallbladder US has a high negative predictive value for bile culture results in cats. This modality is less predictive of infection in dogs. Percutaneous US‐guided cholecystocentesis has a low complication rate.

Cytological Findings of 140 Bile Samples from Dogs and Cats and Associated Clinical Pathological Data

Background

Cholecystocentesis can be part of the diagnostic workup of hepatobiliary disease in small animals, but literature on cytological evaluation of bile is scant.

Objectives

To determine the diagnostic utility of cytological assessment of bile aspirates.

Animals

Fifty‐six and 78 client‐owned dogs and cats, respectively, with bile collected by cholecystocentesis and submitted to our diagnostic laboratory between 1999 and 2014.

Methods

Retrospective study describing cytological findings of bile, concurrent bacterial culture results, hematological and serum biochemical data, gallbladder biopsy results, as well as final diagnosis and complications after cholecystocentesis.

Results

Infectious agents were found in 30% of canine and 22% of feline bile aspirates, and inflammation in 5% and 19% respectively. Presence of microorganisms was more often detected on cytological examination (24%) than by culture (21%). The most common bacterial isolates were Escherichia coli and Enterococcus spp., isolated from 14.8% and 6.7% of cultured samples respectively. Only increased canine pancreatic lipase immunoreactivity concentration (cPLI) was significantly associated with the presence of microorganisms, inflammatory cells, or both in bile. Clinically relevant complications of cholecystocentesis occurred in 2 dogs. The majority of the animals undergoing cholecystocentesis suffered from hepatic, pancreatic, gastrointestinal disease, or a combination thereof.

Conclusions and Clinical Importance

Cytological examination of bile is inexpensive and straightforward, and yields diagnostically relevant information that precedes and complements bacterial culture.