Comparison of the diagnostic yield of 3 and 5 mm laparoscopic liver biopsy forceps in cats

Objective: To determine whether 3 and 5 mm laparoscopic cup biopsy forceps provide samples of equivalent diagnostic quality in cats.

Study design: Experimental study.

Animals: Twelve colony cats undergoing a concurrent nutrition study.

Methods: Two biopsy forceps (3 and 5 mm) and three biopsy techniques (twist, pull, and twist + pull) were used to collect 68 laparoscopic liver samples. Biopsies were performed consecutively with the 3 and 5 mm biopsy sites adjacent to each other. Data analyzed included the number of portal triads and hepatic lobules, tissue crush and fragmentation, overall sample area (mm² ), sample weight, and agreement regarding morphologic diagnosis.

Results: The 5 mm forceps provided more hepatic lobules, portal triads, and a larger tissue weight and histologic area (mm² ) (p < .01). The twist and pull techniques provide more hepatic lobules and portal triads compared to the twist + pull technique while the twist + pull technique resulted in greater tissue crush compared to the twist technique (p = .0097). There was good agreement for morphological diagnosis between the 3 and 5 mm samples using the twist + pull technique but not for the twist or pull techniques.

Conclusion: Liver samples can be safely collected with 3 or 5 mm laparoscopic biopsy forceps and provide sufficient tissue for histopathology analysis in cats, with minimal artifact. The diagnostic accuracy of 3 mm samples remains unknown.

Clinical significance: Although 3 mm laparoscopic cup biopsy forceps provided samples of sufficient diagnostic quality for histopathologic interpretation in cats, further studies are required to assess their diagnostic accuracy.