Comparison of two minimally invasive techniques for liver biopsy collection in dogs

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

OBJECTIVE

To 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 DESIGN

Clinical prospective study.

ANIMALS

Ten client-owned dogs, presenting for laparoscopic liver biopsy (LLB).

METHODS

Dogs 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.

RESULTS

Both 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).

CONCLUSION

The 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 SIGNIFICANCE

In dogs, a 3 mm CBF yields adequate samples for histopathologic interpretation, copper quantification, and bacterial culture.

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.

Laparoscopic twist technique has the best overall artifact profile when comparing three laparoscopic hepatic cup biopsy techniques for dogs

OBJECTIVE

To determine the difference in histologic artifacts and morphologic diagnosis among 3 laparoscopic cup biopsy forceps techniques and wedge hepatic samples.

ANIMALS

Cadavers of 20 client-owned dogs following euthanasia for unrelated reasons between January 3 and July 29, 2021.

PROCEDURES

Four biopsy techniques were performed from the margin of 3 liver lobes/dog. Laparoscopic techniques used 5-mm cup biopsy forceps to obtain biopsy samples by pulling the forceps forcefully caudally to free a sample (the PULL technique), rotating the forceps 360° in 1 direction until freed (the TWST technique), or pulling the forceps through a 5-mm cannula to remove the sample (the CAN technique); wedge biopsy samples served as the control (CON). Data collected included sample weight, histologic features, diagnosis, and artifact characterization. Gwet AC1 or intraclass correlation coefficients (ICCs) were calculated to detect agreement among techniques.

RESULTS

Sample weights for CON and TWST were significantly larger (P < .001 and P = .035, respectively) than for PULL and CAN. There was excellent agreement among all techniques for most diagnostic features (Gwet AC1, 0.93 to 1). The TWST technique resulted in the best overall artifact profile for laparoscopic techniques, with 90% of samples (54/60) having crisp edges and 65% of samples (39/60) having no or mild tearing. The agreement was moderate to good (ICC, 0.73 for edges and 0.76 for tearing) among all cup biopsy forceps techniques.

CLINICAL RELEVANCE

The TWST technique resulted in the largest sample and had the fewest artifacts, supporting its continued use during laparoscopic procedures.

Comparative Oncology: Management of Hepatic Neoplasia in Humans and Dogs

Primary hepatic neoplasia is uncommonly reported in dogs. Hepatocellular carcinoma (HCC) is the most frequent neoplasia identified in dogs and considerable effort has been committed towards identifying definitive and palliative treatment options. HCC is well recognized in humans as a sequelae of liver disease such as hepatitis or cirrhosis, while in dogs a similar link has failed to be fully elucidated. Management of HCC in people may be curative or palliative dependent on staging and transplant eligibility. Despite differences in etiology, there is substantial similarity between treatment options for liver neoplasia in human and veterinary medicine. The below summary provides a comparative discussion regarding hepatic neoplasia in dogs and people with a specific focus on HCC. Diagnosis as well as descriptions of the myriad treatment options will be reviewed.

Evaluation of a pre-tied ligature loop for canine total lung lobectomy

OBJECTIVE

To determine the ability of a pre-tied ligature loop (PLL) to create a seal against physiological airway pressures after total lung lobectomy and report outcomes in dogs requiring lung lobectomy.

STUDY DESIGN

Ex vivo experimental randomized study and clinical case study.

SAMPLE POPULATION

Thirty cadaveric canine lung lobes and 5 client-owned dogs.

METHODS

Thirty canine lung lobes from dogs weighing 22.5-35 kg were randomized to lobectomy with stapler, PLL, or suture ligation. After lobectomy, each bronchial stump was submerged in water, and the mainstem airway pressure was increased to 80 mm Hg. Leakage was compared between techniques. The PLL was subsequently used in 5 dogs (17-25 kg) with neoplastic disease requiring total lung lobectomy.

RESULTS

Two stapled and 4 sutured bronchial stumps leaked at supraphysiological pressures >15 mm Hg. One stapled bronchial stump failed at a physiological airway pressure (5 mm Hg). None of the PLL lobectomies leaked. The incidence of bronchial stump failures did not differ among techniques (P = .15). Lung lobectomy was performed successfully with the PLL in 5 clinical cases with no intraoperative or postoperative complications; median follow-up time was 6 months.

CONCLUSION

Bronchial ligation with the PLL reliably resisted physiological airway pressures and performed comparably to current standard techniques in cadavers. The PLL provided an adequate air and vascular seal in 5 clinical cases undergoing total lung lobectomy.

CLINICAL RELEVANCE

Pre-tied ligature loops provide an alternative method for total lung lobectomy in dogs.