Pilot evaluation of a vacuum-assisted biopsy instrument for percutaneous renal biopsy in dogs

Gasless laparoscopic renal biopsy in canine cadavers: a preclinical study

In this study we aimed to analyze the feasibility of the gasless renal biopsy technique in canine cadavers. The cadavers were randomly divided into two groups: laparoscopic GCG, in which gasless laparoscopy was performed and GCP, laparoscopy with pneumoperitoneum was performed. The procedures were randomly performed on the right and left kidneys. The total surgical time, procedural steps, and intraoperative complications were recorded. The degree of difficulty of the surgical approaches was evaluated by the surgeon, assistant, and external evaluators. Renal samples were evaluated for quality, number of glomeruli, and proportion of renal cortex. The total operative time was higher in the GCG group than in the GCP group (p < 0.01). Additionally, positioning of the second portal and platform positioning took longer than the other steps. The surgical groups differed from each other in the Likert scale values for almost all the parameters regarding the difficulty of the surgical approaches (p < 0.05), with higher scores in the GCG group than in the GCP group. Based on the video recordings, the GCP group had higher scores than the GCG group for degrees of difficulty of the approach (p < 0.05). Renal histological parameters were similar between the surgical groups and surgical sides. Our study findings indicate that the proposed gasless renal biopsy technique is feasible. The longer operative time and technical difficulties in the gasless approach did not affect the quality of the renal specimens.

Learning curve for the laparoscopy-guided kidney biopsy procedure in small corpses of dogs and pigs

The use of renal biopsy through laparoscopy is increasingly present both in human and veterinary medicine. However, both techniques require skill and training to make the operator capable to do it. The learning curve allows the quantitative and qualitative assessment of the number of attempts and minimum time for the surgical procedure. The objective included establish the learning curve for laparoscopy-guided kidney biopsy procedures in dog and pig corpses. Six dogs and six pigs corpses weighing less than 10 kg were used for this study. All corpses underwent kidney biopsy performed through laparoscopy. Twenty-four operators, two per animal, performed 20 renal biopsies each (10 for each kidney), with 480 collection-procedures in total. Duration and difficulty of the procedure and the biopsy sample quality were evaluated and statistical analysis was performed using a mixed regression model with a random effect of individuals and multivariate analysis of data. There were 91.5% of the samples that were adequate for evaluation. There was no significant difference in the number of glomeruli or cortex percentage considering the attempts in either species, demonstrating the operator's ability since first collection. Swine samples showed higher amounts of renal cortex than canine samples. The procedure duration was shorter as more attempts were performed in dogs and pigs. From the fourth repetition, the professional reached a plateau for the variable related to 'collection', and from the second, the professional presented uniform duration for 'sample storage'. Operators of the swine model acquired more agility than the dog ones. The variable 'difficulty' decreased as more repetitions were performed, reaching a plateau in the sixth attempt. Seven renal biopsies laparoscopy-guided are required for an operator to be considered 'capable' to perform the procedure in the referred species included. The learning curve for image-guided kidney biopsy procedures improves the implementation of this technique and benefits patients that undergo this procedure.

Evaluation of the diagnostic utility of cytologic examination of renal fine-needle aspirates from dogs and the use of ultrasonographic features to inform cytologic diagnosis

OBJECTIVE To describe cytologic characteristics of renal fine-needle aspirate (FNA) samples from dogs, evaluate proportions of cytologic specimens deemed adequate for interpretation (diagnostic yield), assess diagnostic utility of cytologic examination for neoplastic and nonneoplastic diseases, and characterize ultrasonographic features of evaluated kidneys to determine whether the imaging characteristics could be used to inform cytologic interpretations. DESIGN Retrospective, observational study. SAMPLE 102 cytologic specimens and 97 ultrasonographic studies from 100 dogs. PROCEDURES Medical records were reviewed to identify dogs that underwent ultrasound-guided renal FNA. Slides were categorized as adequate or inadequate for interpretation; adequate slides were used for retrospective cytologic diagnosis. Sensitivity, specificity, and predictive values of cytologic examination for detection of neoplastic and nonneoplastic conditions were calculated by comparison with histologic or lymphoid cell clonality assay results. Ultrasonographic characteristics of neoplastic and nonneoplastic renal lesions were described. RESULTS 74 of 102 (72%) specimens had slides adequate for interpretation; 26 were included in the diagnostic accuracy analysis. Sensitivity of cytologic examination was 78% and 50% for detection of neoplastic and nonneoplastic conditions, respectively, with specificities of 50% and 77%, respectively; sensitivity for detection of lymphoma was 100%. Ultrasonographic appearance of kidneys with confirmed neoplasia varied; masses were most commonly found in kidneys with carcinoma (5/5), lymphoma (5/7), or other neoplasia (3/4) and absent in kidneys with nonneoplastic conditions (n = 5). CONCLUSIONS AND CLINICAL RELEVANCE Renal FNA specimens were adequate for interpretation at rates comparable with those reported for other organs and were considered clinically useful for diagnosis of neoplasia. Imaging characteristics may potentially aid differentiation between neoplastic and nonneoplastic lesions; however, further investigation is needed.

Laparoscopic kidney biopsy in dogs: Comparison of cup forceps and core needle biopsy

OBJECTIVE

To investigate the feasibility of laparoscopic kidney biopsy with cup biopsy forceps in dogs (CupBF), and to compare to the use of a core biopsy needle (CoreBN).

STUDY DESIGN

Experimental; randomized, controlled design.

ANIMALS

Eight healthy, adult Beagle dogs.

METHODS

Dogs were randomized to undergo laparoscopic biopsy of the right kidney using either 5 mm CupBF or a 16 gauge CoreBN. Intraoperative hemorrhage of the biopsy site was monitored. Biopsy quality was evaluated for tissue fragmentation and crushing, presence of renal cortex with or without medulla, and number of glomeruli. Postoperative packed cell volume, urinalysis, and ultrasonographic appearance of the biopsy site were evaluated.

RESULTS

Biopsy specimens were obtained by both techniques and reliable hemostasis was achieved with direct compression in all dogs. The histologic score for CupBF biopsies was not significantly different from CoreBN biopsies. One CoreBN biopsy contained both renal cortex and medullar, while all CupBF biopsies contained cortex only. The mean (SD) number of glomeruli was significantly higher in CupBF biopsies [60 (9.1)] than CoreBN biopsies [26 (4.3)]. There was no gross hematuria, perirenal hematoma, or hydronephrosis in any dog postoperative.

CONCLUSION

Laparoscopic kidney biopsy in dogs using 5 mm cup biopsy forceps is feasible with minimal risk and more glomeruli obtained compared to laparoscopic kidney biopsy using 16 gauge core biopsy needles.