Comparison of diagnostic accuracy of laparoscopic 3 mm and 5 mm cup biopsies to wedge biopsies of canine livers

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.

Feasibility of hepatic fine needle aspiration as a minimally invasive sampling method for gene expression quantification of pharmacogenetic targets in dogs

Background

Quantifying hepatic gene expression is important for many pharmacogenetic studies. However, this usually requires biopsy (BX), which is invasive.

Objectives

The objectives of this study were to determine the feasibility of using minimally invasive fine needle aspirate (FNA) to quantify hepatic gene expression and to assess expression variability between different sampling sites.

Methods

Biopsy and FNA samples were acquired from central and peripheral locations of the right and left lateral liver lobes of a dog. Relative expression of ABCB1, GSTT1 and CYP3A12 were measured via reverse transcriptase, quantitative PCR. The effect of sampling method, lobe and location within the lobe on gene expression was assessed using a three‐way ANOVA.

Results

Relative expression of ABCB1 and GSTT1 were not statistically different between sampling methods but CYP3A12 expression was higher in samples collected by BX (p = .013). Lobe sampled affected ABCB1 expression (p = .001) and site within lobe affected ABCB1 (p = .018) and GSTT1 (p = .025) expression.

Conclusions

FNA appears to be a feasible technique for minimally invasive evaluation of hepatic gene expression but results should not be directly compared to biopsy samples. Sampling location impacts expression of some targets; combination of FNAs from multiple sites may reduce variation.

Comparison of diagnostic accuracy of laparoscopic 3 mm and 5 mm cup biopsies to wedge biopsies of canine livers

BACKGROUND

Diagnostic accuracy of the 3 mm laparoscopic cup biopsy forceps for collection of tissue samples from canine livers is unproven.

HYPOTHESES/OBJECTIVES

Compare sample surface area and portal triad count between 3 mm and 5 mm laparoscopic cup biopsies and compare the histologic diagnosis obtained by each instrument to a standard necropsy wedge. The hypothesis was that more portal triads and greater sample surface area would be found with the 5 mm samples and the laparoscopic instruments would not have significantly different levels of agreement with necropsy wedge diagnosis.

ANIMALS

Twenty-one client-owned dogs undergoing necropsy.

METHODS

Prospective ex vivo study. Three samples (3 mm, 5 mm, and wedge) were taken of 2 different hepatic divisions within 24 hours of death. Morphologic diagnosis, World Small Animal Veterinary Association histologic features, surface area, and portal triad numbers were compared among the 3 samples.

RESULTS

There were significantly more portal triads (mean 21.4 versus 13.8; P < .0001) and a higher surface area (20.3 mm² versus 11.5 mm² ; P < .0001) in the 5 mm samples compared to 3 mm samples. Kappa coefficients and percent agreement for histologic diagnosis as compared to the wedge biopsy were not significantly different between the 2 instrument sizes (κ = 0.383 and 0.436, respectively; 67% and 69%, respectively).

CONCLUSIONS AND CLINICAL IMPORTANCE

Despite yielding smaller sample sizes, the 3 mm laparoscopic cup biopsy has a similar level of histologic diagnostic accuracy to the 5 mm instrument.