The use of agitated saline as contrast agent in a contrast-enhanced cystosonography for detection of urinary bladder rupture in animal cadavers.

OBJECTIVE

To determine the value of microbubble contrast cystosonography in the diagnosis of bladder rupture in animals.

DESIGN

Prospective, method comparison study from November 2019 to October 2020.

SETTING

University teaching hospital.

ANIMALS: Thirty-four ethically sourced cadavers of dogs, rats, and rabbits.

INTERVENTIONS: In a prospective and blinded study, the cadavers were divided into 2 randomized groups: with bladder rupture (CR), and without bladder rupture (SR). Urinary catheterization was performed in all cadavers. Through the urethral catheter, bladders in CR group were ruptured using a rigid stainless steel guide wire. Microbubble contrast was infused into the bladder through the urethral catheter, while a single, blinded observer sonographically assessed the bladder. The time to diagnosis and the number of attempts needed for diagnosis were recorded.

MEASUREMENTS AND MAIN

RESULTS

The study included cadavers of 16 female Wistar rats, 6 female dogs, 11 male dogs, and 1 male rabbit. Time to diagnosis in dogs (2.25 ± 0.91 min) was statistically higher when compared to rats (1.15 ± 0.75 min; P = 0.03). Of the 34 cases, incorrect diagnosis of bladder rupture was made in only 2 dogs (6%), indicating a diagnostic sensitivity of 88.88%, specificity of 100%, and an accuracy of 94%. The positive predictive value was 1 and the negative predictive value was 0.9.

CONCLUSIONS

Our study showed that the described method is accurate, sensitive, and specific for the detection of bladder rupture in animal cadavers of different species, size, and sex.