Comparing 3 mm and 5 mm laparoscopic liver biopsy samples in dogs

ObjectiveTo determine whether 3 mm cup biopsy forceps (CBF) provide equivalent diagnostic samples to 5 mm CBF for histopathologic diagnosis, bacterial culture, and copper quantification. Study designClinical prospective study. AnimalsTen client-owned dogs, presenting for laparoscopic liver biopsy (LLB). MethodsDogs underwent LLB, and paired samples were collected using 3 and 5 mm CBF. Portal triad and hepatic lobule counts, crush and fragmentation artifacts, copper concentration, bacterial culture results, and agreement on histopathologic diagnosis were compared. ResultsBoth CBF sizes allowed for easy sample collection and resulted in minimal hemorrhage. An average of 12.13 (confidence limit (CL): 9.4-14.9) and 17.84 (CL: 15.1-20.6) portal triads were obtained using a 3 and 5 mm CBF, respectively (p = .0003). A portal triad count of 11 or more was achieved in 73.3% of the 3 mm and 93.3% of the 5 mm samples. Gwets AC1 coefficient showed a high level of agreement (0.8) for overall histopathologic diagnosis (p < .0001). The 3 mm CBF crush scores were higher (median of the differences: -1; range: -1 to 1) (p = .035). There was no difference in fragmentation scores (p = .935). ConclusionThe 3 mm CBF yielded smaller samples in terms of size and portal triad count compared with the 5 mm CBF. However, the portal triad count was sufficient in a majority of samples and histologic agreement with the 5 mm CBF was excellent. Clinical significanceIn dogs, a 3 mm CBF yields adequate samples for histopathologic interpretation, copper quantification, and bacterial culture.