Ultrasound-guided serial transabdominal cardiac biopsies in cats

A percutaneous/transdiaphragmatic core needle biopsy technique was developed in cats to obtain serial biopsies from different locations of the left ventricle, through which morphological and molecular changes within the same individual can be studied to unravel the mechanisms of feline cardiomyopathies. Transmural left ventricular myocardial samples were obtained from 29 anesthetized, healthy, adult cats with ultrasound guidance. An 18G automatic biopsy needle was inserted between the last left rib and the sternum through the diaphragm into the thorax. Biopsies were obtained from the left ventricular wall. In five cats, three single biopsies were taken with 4-week intervals. Autopsy was performed on six cats, of which three cats had serial biopsies. In total, 87 biopsies were obtained without long-term effects on cardiac function or structure. The biopsies caused transient single ventricular premature complexes and mild pericardial effusion without tamponade. Necropsy revealed a minimal amount of fibrous connective tissue in the diaphragm and the heart without any significant microscopic lesions in the adjacent muscle tissue. The high quality biopsy material was suitable for morphological and molecular studies. This minimally invasive, ultrasound-guided cardiac biopsy technique thus allows for the safe collection of serial biopsies to study feline cardiomyopathies in an experimental setting.