ULTRASOUND-GUIDED TISSUE-CORE BIOPSY OF LIVER, SPLEEN AND KIDNEY IN NORMAL DOGS

Six normal dogs were subjected to ultrasound-guided biopsy of the liver, spleen and kidney to examine the accuracy of the technique (i.e. the presence of targeted tissue) and the histologic quality of the biopsies. Five consecutive tissue-core biopsies of each organ were taken on one or more occasions. The accuracy of the technique was 77% for hepatic, 90% for splenic, 53.5% for left kidney and 40% for right kidney biopsies. The histologic quality of the liver and kidney samples was sufficient, although for some samples the diagnostic value was limited by their size and in renal samples either cortical or medullary tissue was sometimes lacking. In contrast, the quality of the splenic sections was not good. The effect of reused and resterilized needles on the quality of the specimens was evaluated by histologic inspection of the samples and by the amount of biopsies lacking tissue. All tissue samples, including those taken with reused or resterilized needles had sharp-cut edges. Twenty-two of the total number of 120 biopsies (18%) contained no tissue. Absence of tissue in the samples was observed in biopsies taken with all needle types. The animals were observed for possible complications of the repeated needle biopsy. Apart from one case of hematuria, no complications were encountered.     

Efficacy and safety of ultrasound-guided percutaneous biopsy of the right kidney in cattle

The purpose of the present study was to develop a technique for biopsy of the kidneys of cattle and to evaluate its usefulness and safety based on 25 consecutive biopsies. Using a handheld 14G spinal biopsy needle, the right kidney was biopsied under ultrasound control by one operator. To assess the immediate effects of renal biopsy, twenty cattle were necropsied shortly after the procedure and examined. The remaining five animals were biopsied and examined daily for nine days and then necropsied. One pass was made for biopsy of the right kidney. No immediate or delayed macroscopic hematuria was observed post-biopsy. Six animals had a thin subcapsular hematoma (less than 2 cm in diameter). We conclude that percutaneous ultrasound-guided biopsy of the right kidney is safe, fast, cost-effective and practical as long as it is performed properly.     

A multicenter retrospective study of 151 renal biopsies in horses

Background: Renal biopsies are uncommonly performed in horses and little is known about their diagnostic utility and associated complication rate. Objective: To describe the techniques, the complication rate, risk factors, and histopathology results; as well as evaluate the safety and diagnostic utility of renal biopsy in the horse. Animals: One hundred and forty‐six horses from which 151 renal biopsies were obtained. Animals ranged in age from 48 hours to 30 years. Methods: Multicenter retrospective study, with participation of 14 institutions (1983–2009). Results: Renal biopsy in horses was associated with a similar rate of complications (11.3%) to that occurring in humans and companion animals. Complications were generally associated with hemorrhage or signs of colic, and required treatment in 3% of cases. Fatality rate was low (1/151; 0.7%). Biopsy specimens yielded sufficient tissue for a histopathologic diagnosis in most cases (94%) but diagnoses had only fair (72%) agreement with postmortem findings. Risk factors for complications included biopsy specimens of the left kidney (P= .030), a diagnosis of neoplasia (P= .004), and low urine specific gravity (P= .030). No association with complications was found for age, sex, breed, institution, presenting complaint, other initial clinicopathologic data, biopsy instrument, needle size, or use of ultrasonographic guidance. Conclusions and Clinical Importance: Renal biopsy in horses has low morbidity and results in a morphological histopathologic diagnosis in 94% of cases. However, this procedure might result in serious complications and should only be used when information obtained would be likely to impact decisions regarding patient management and prognosis.     

ULTRASOUND LOCALIZATION AND GUIDANCE FOR RENAL BIOPSY IN THE HORSE

Real-time ultrasonography was used to assist percutaneous renal biopsies in seven normal horses. Ultrasound (US) guidance and blind biopsy following US localization were compared. Ten biopsies (seven right kidney and three left kidney) were performed. A transverse approach to the lateral border of the right kidney through the 17th intercostal space was favored, with the needle angle being approximately perpendicular to the body wall. Both biopsy techniques were effective, but blind biopsy following US localization was favored as it was easily performed by one operator without the need for specialized biopsy equipment. The spleen had a variable location and its penetration with the biopsy needle was necessary to obtain two left kidney biopsies. Macroscopic and microscopic hematuria was observed postbiopsy in one and four horses, respectively, out of six horses examined. Perirenal hemorrhage was a prominent finding on necropsy in five of six horses euthanized.     

Percutaneous biopsy of abdominal organs under ultrasound guidance

Percutaneous sampling of one or more abdominal organs was performed under ultrasound guidance in 89 dogs and 16 cats. Tissue core samples were considered to be of diagnostic quality in 92 per cent of hepatic and 100 per cent of renal biopsies. Core biopsies were collected from the prostate in only three cases but each was adjudged of diagnostic quality. The technique allowed a definitive diagnosis or normal tissue to be confirmed in 65 per cent of animals undergoing hepatic biopsy, 83 per cent undergoing renal biopsy and 82 per cent undergoing prostatic biopsy or aspiration. Few complications occurred which could be ascribed with certainty to the procedure. One dog with extensive hepatic necrosis died one week after the biopsy, but necropsy examination was denied. One severely debilitated cat did not recover from general anaesthesia. One dog underwent aspiration of a sterile intraprostatic cyst, and developed prostatic abscessation one week later; prostatic carcinoma was subsequently found. Careful selection and preparation of patients for biopsy are essential. With this caveat, ultrasound-guided sampling of abdominal organs is a useful technique allowing a definitive diagnosis in a high proportion of cases. The technique is minimally invasive and the complication rate low.     

Percutaneous transabdominal hepatic needle biopsies in dogs.

Ninety-six (4/dog) percutaneous transabdominal hepatic needle biopsy specimens were obtained from 24 dogs each weighing 10 to 24 kg. Two biopsies were performed in each dog prior to and 5 days after hepatopathy was experimentally induced. Information pertaining to the difficulty encountered in obtaining hepatic tissue is reported for the first of each pair of biopsies. All specimens were of diagnostic quality for light and electron microscopic evaluation. Adverse consequences (morbidity or mortality) resulting from the biopsy technique were not observed by monitoring of vital signs in the immediate postprocedure period and at 4 weeks. Recovery to an ambulatory state was seen in less than or equal to 30 minutes, except in 1 dog, in which prolonged recovery was attributed to acetylpromazine-induced hypotension.     

Renal biopsy in the normal cat: examination of the effects of repeated needle biopsy

Three healthy cats were subjected to percutaneous renal biopsy of the left kidney on three occasions at monthly intervals. Three other cats were subjected to three consecutive biopsy attempts on one occasion using the left kidney. Thereafter the six cats were monitored clinically and by means of laboratory analyses of blood and urine until euthanasia four weeks after the last biopsy. Cautious insertion of the biopsy needle in an attempt to avoid over penetration of the kidney resulted in failure to obtain renal tissue on six occasions but in all 12 specimens which did contain renal tissue, glomeruli were present. Major blood vessels were present in two biopsy specimens. At necropsy, radiographic and histological studies demonstrated renal parenchymal and vascular changes in the biopsied kidneys which were similar to but less severe than those produced by a single biopsy attempt. This confirmed that avoidance of damage to major renal vessels is important and suggested that, with care, repeated biopsies need be no more harmful to the kidney than a single biopsy.     

THE EFFECTS OF A UNILATERAL ULTRASOUND-GUIDED RENAL BIOPSY ON RENAL FUNCTION IN HEALTHY SEDATED CATS

Complications of renal biopsies are well documented except for the change in renal function after a biopsy. Eighteen healthy, adult cats were divided into two groups (n = 9 cats/group). For the measurement of global and split renal function, Group 1 used the renal uptake of 99mTc-DTPA and Group 2 used the renal uptake of 99mTc-MAG3. Scintigraphic data were collected on days (-4), (-3), 0, 1, 2, and 4 post renal biopsy. Using ultrasound guidance, biopsies were taken from the right renal cortex on dO, before acquiring scintigraphic images. P - values less than 0.10 were considered significant due to the limited number of observations. The only statistically significant change (p = 0.08) in global renal function detected was by day following a unilateral renal biopsy. Cats imaged using 99mTc-MAG3 had discernible liver activity. A unilateral, ultrasound guided renal biopsy has minimal effect on renal function in normal, healthy sedated cats.     

Effects of serial ultrasound-guided renal biopsies on kidneys of healthy adolescent dogs

Ten healthy mixed-breed dogs were used to evaluate the functional and structural effects of serial ultrasound-guided renal biopsies obtained with an automated biopsy needle. In each dog, one lateral renal cortex was biopsied at 2, 4, and 6 months of age; the other kidney was the control. Five dogs had two tissue cores and five dogs had four tissue cores taken on each biopsy occasion, and one core was examined microscopically. One week before each biopsy and a month after the final biopsy, the glomerular filtration rate (GFR) was determined by renal scintigraphy. Dogs were then euthanized for evaluation of gross and microscopic lesions attributable to the biopsies. There was no difference between GFR values for biopsied kidneys and those of control kidneys ( P >0.05). Microscopic lesions were not identified in biopsies taken at 2 and 4 months, but focal lesions were found in three of 10 specimens taken at 6 months of age. At necropsy, six of 10 biopsied kidneys had small visible capsular scars, and linear tracts <2 mm wide were observed on cut surfaces in six of 10 biopsied kidneys cut transversely into slices 5 mm thick. Discrete light microscopic lesions were observed in 25 of 452 (5.5%) of randomly selected 6-mm-diameter sections of renal cortex from biopsied kidneys. We conclude that serial renal cortical biopsies can be obtained by our method from healthy adolescent dogs with minimal risk of inducing changes that might be confused with those of a progressive renal disease.     

Evaluation of laparoscopy for obtaining renal biopsy specimens from dogs and cats

Laparoscopic direction of renal biopsy was evaluated in 37 dogs and 1 cat suspected of having renal disease. Specimens adequate for morphologic diagnosis were obtained in 37 cases (97%). Eleven of the 38 animals were necropsied and the biopsy diagnosis was confirmed in 10 of the cases (91%). Excessive pericapsular hemorrhage and severe hematuria developed in 1 dog. Three dogs (8%) had macroscopic hematuria for 24 hours after biopsy.     

Laparoscopic-assisted serial biopsy of the bovine kidney

A serial renal biopsy with endoscopy was done, using 10 calves and a cow. In 8 of the calves, biopsy materials were collected 3 to 5 times over a period of 15 to 41 days. A laparoscope was inserted into the peritoneal cavity from the center of the right paralumbar fossa through the outer cannula of the trocar. Under laparoscopic observation, the renal parenchyma was collected with the cutting prong of a biopsy needle. Of 34 biopsy attempts, 32 were successful; in 2, there was incomplete penetration of the trocar assembly into the peritoneal cavity. In one instance, the trocar was misguided to the small intestine which was closely adherent to the peritoneum. The error may have been the result of the presence of a persistent blood clot resulting from the preceding biopsy. An immediate saline rinse of the blood clot attached to kidney and the surrounding tissues was effective in preventing such adhesions. The size of the average sample obtained was 1.5 mm in diameter and 16 mm (2 to 40 mm) long. The tissues were collected in 61 times from the 72 insertions of the biopsy needle to the renal tissue. The 11 unsuccessful attempts were caused by bluntness of the cutting parts of the needle. Adverse clinical signs were no observed after the serial biopsy of kidney, except for the presence of blood in he urine persisting for 1 to 5 days. Although a dehydrated blood clot was found in the renal pelvis of one animal at necropsy, any complication such as obstruction of urinary flow was not observed.     

Sensitivity of Tru-cut and fine needle aspiration biopsies of liver and kidney for diagnosis of feline infectious peritonitis

BACKGROUND: The detection of typical lesions and feline coronavirus (FCoV) antigen in tissues is the only conclusive method for making a diagnosis of feline infectious peritonitis (FIP). A positive result using Tru-cut biopsy (TCB) and fine-needle aspiration biopsy (FNAB) has high diagnostic specificity, but information about the capacity of these techniques to correctly identify cats with FIP lesions is not available. OBJECTIVES: The diagnostic sensitivity of TCB and FNAB for detecting liver and kidney histologic lesions caused by FIP was evaluated. METHODS: TCB and FNAB specimens collected mainly at necropsy from 25 cats with FIP were analyzed. Diagnostic sensitivity was calculated on the basis of the number of false-negative and true-positive specimens, compared with the number of organs bearing histologic lesions of FIP. RESULTS: Diagnostic sensitivity was higher for hepatic TCB (64%) and FNAB (82%) than for renal (39% and 42%, respectively) procedures. A high percentage of renal cytologic and TCB specimens were inadequate. Combined analysis of TCB and FNAB specimens collected from the same organ increased the diagnostic sensitivity for liver (86%) and kidney (48%). The sensitivity of immunohistochemical/cytochemical analysis was low (11-38% depending on the technique), probably due to variable distribution of feline coronavirus in the lesions. CONCLUSION: Biopsy of liver and kidney can correctly identify FIP lesions. However, false-negative results or inadequate samples occur with moderate frequency, especially for immunochemical analysis. Diagnostic sensitivity may be increased when both TCB and FNAB specimens from the same organ are examined.     

Liver biopsy as a technique for assessing copper status of sheep

A procedure for taking biopsy samples from the ovine liver by a paracostal route is described. Samples were taken from 120 Merino rams on up to 3 occasions over a 3 month period. At the end of the period, the rams were subjected to 2 further biopsies and were then slaughtered, and the liver was removed and homogenised. Copper contents of all samples were determined.
Frequency of biopsy did not affect hepatic copper concentration which was significantly overestimated by the biopsy method by approximately 5%. Variability associated with the biopsy procedure was approximately ± 30 to 40 mg Cu/kg DM (SD) and was small relative to variability between animals. Experimental designs were preferred in which samples are taken before and after treatments are applied; changes in concentration are then analysed. Such analyses eliminate errors associated with variability between animals and the small bias in the sampling procedure. Liver biopsy did not significantly reduce bodyweight or the rate of gain.     

Bilateral kidney translocation in sheep

Bilateral kidney translocation was performed on 7 adult sheep. In each sheep, we took 9 renal biopsy specimens (40 mg each) percutaneously between 36 and 110 days after surgery. The serum urea nitrogen and creatinine concentrations remained normal, at least through postoperative day 66 (7 biopsy specimens). The 7 sheep were euthanatized and necropsied 113 days after surgery; 75 to 90% of each kidney was normal. The only abnormal areas of each kidney were attributable to resolving biopsy lesions. This surgical model may allow for fewer animals to be used for tissue residue or nephrotoxicity studies.     

Scintigraphic, sonographic, and histologic evaluation of renal autotransplantation in cats.

OBJECTIVE: To determine scintigraphic, sonographic, and histologic changes associated with renal autotransplantation in cats. ANIMALS: 7 adult specific-pathogen-free cats: 5 males, 2 females, 1 to 9 years old. PROCEDURE: Renal autotransplantation was performed by moving a kidney (5 left, 2 right) to the left iliac fossa. Before and at multiple times after surgery, for a total of 28 days, cats were evaluated by B-mode and Doppler ultrasonography, scintigraphy, and renal biopsy. RESULTS: By 24 hours after surgery, a significant decrease (42%) in mean glomerular filtration rate (GFR) and an increase in mean renal size (81% increase in cross-sectional area) were evident in the transplanted kidney, compared with preoperative values. By postsurgery day 28, reduction in GFR was 23%. Significant changes in renal blood flow velocity were identified in both kidneys. Consistent changes in resistive index or pulsatility index for either kidney could not be identified. When all postoperative histologic data were combined, the histologic score, indicating degree and numbers of abnormalities detected, for the transplanted kidney was significantly higher than that for the control kidney. CONCLUSIONS: Significant changes in renal function, size, and histologic abnormalities develop secondary to acute tubular necrosis in cats after uncomplicated renal autotransplantation. CLINICAL RELEVANCE: Evaluation of renal size and function may be of benefit for clinical evaluation of feline renal transplant patients, whereas measurement of the resistive index may be of little clinical value.     

Glomerulonephritis in water buffaloes (Bubalus bubalis) naturally infected by Fasciola hepatica

Glomerulonephritis caused by Fasciola hepatica was observed in buffaloes. Renal biopsies of 20 buffaloes, 11 with F. hepatica and 9 uninfected buffaloes (controls), were examined by light microscopy, direct and indirect immunofluorescence, and immunohistochemical analysis. The biopsies of seven (63.6%) infected buffaloes revealed membranoproliferative glomerulonephritis, three biopsies (27.3%) showed mesangioproliferative glomerulonephritis, and one kidney presented normal biopsy specimens. In the control group, seven buffaloes (77.8%) presented normal biopsy specimens, while two (22.2%) revealed glomerulonephritis-one with a membranoproliferative pattern, and the other with a mesangioproliferative pattern-with extensive inflammatory cell infiltrate. Our conclusion is that glomerulopathy is associated with fascioliasis and that buffaloes are suitable as a naturally existing experimental model of renal injury by circulating immune complexes.     

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

Kidney biopsies in dogs are commonly obtained using automated spring-loaded biopsy instruments. Interpretation of biopsies from dogs with glomerular disease requires examination of at least 5-10 glomeruli, with at least two biopsies usually required for full evaluation. The purpose of this study was to compare quality and interpretability of renal biopsies obtained from healthy dogs with a large-gauge, vacuum-assisted biopsy instrument versus two biopsies obtained with a spring-loaded biopsy needle. Twenty dogs were randomized into two groups, and percutaneous, ultrasound-guided renal biopsies were evaluated using standard criteria. There were no significant differences in the number of biopsies that contained renal tissue, cortex, or medulla. Biopsies obtained with either instrument contained an adequate number of glomeruli and an equivalent number of arterioles and severity of tissue compression. Differences included easier penetration of the renal capsule and collection of sufficient tissue for interpretation with only one instrument pass when using the vacuum-assisted device (vs two passes required with the spring-loaded instrument). Before use in client-owned dogs, future studies should evaluate whether these differences are clinically relevant advantages in the diagnostic evaluation of dogs with kidney disease, and determine the prevalence and severity of complications when using this larger gauge device.     

A Retrospective Analysis of Renal Carcinoma in the Horse

Background: Renal carcinoma is a rare tumor of horses.
Hypothesis: Presenting complaints and clinical signs of this disease are vague and early diagnosis increases survival time.
Animals: Data were collected from the medical records of 4 horses presented to Washington State University as well as the 23 previously published case reports of horses with renal carcinoma.
Methods: Retrospective study.
Results: Renal carcinoma affects horses of all ages with most cases observed in geldings and Thoroughbreds. The most common presenting complaints are nonspecific and usually do not occur until late in the course of the disease. Routine laboratory results generally are unremarkable with no evidence of renal dysfunction. Urine and peritoneal fluid analyses are consistently abnormal, but the changes usually are nonspecific. Rectal palpation often allows detection of an abnormal kidney or a mass in the area of the kidney. Renal ultrasound examination is the most rewarding imaging procedure, and when combined with renal biopsy, antemortem diagnosis can be achieved. Renal carcinoma is both locally invasive and metastatic, necessitating careful staging for metastasis using thoracic radiography and abdominal ultrasound examination. If the tumor is localized to 1 kidney, nephrectomy is the treatment of choice. No chemotherapy or radiation treatment for renal carcinoma has been reported in the horse. Median survival for this series of cases was 11 days (0 days–1 year).
Conclusions and Clinical Importance: Prognosis is poor to grave.     

Renal biopsy: a retrospective study of methods and complications in 283 dogs and 65 cats

Renal biopsy often is required to establish a definitive diagnosis in dogs and cats with renal disease. In this retrospective study, we determined the complications of renal biopsy as well as factors that may be associated with development of complications and procurement of adequate renal biopsy specimens in 283 dogs and 65 cats. Data extracted from medical records at 4 institutions were evaluated using logistic regression. Proteinuria was the most common indication for renal biopsy in dogs. Complications were reported in 13.4 and 18.5% of dogs and cats, respectively. The most common complication was severe hemorrhage; hydronephrosis and death were uncommon. Dogs that developed complications after renal biopsy were more likely to have been 4 to < 7 years of age and > 9 years, to weigh < or = 5 kg, and to have serum creatinine concentrations > 5 mg/dL. The majority of biopsies from both dogs (87.6%) and cats (86.2%) were considered to be of satisfactory quality. Biopsies from dogs were more likely to be of high quality if they were obtained when the patient was under general anesthesia and more likely to contain only renal cortex if they were obtained by surgery. We concluded that renal biopsy is a relatively safe procedure, with a low frequency of severe complications. Hospital practices and patient variables have the potential to impact both the quality of the specimen obtained and the rate of complications.     

Effect of nephrotomy on renal function and morphology in normal cats

OBJECTIVE: To assess effects over 12 weeks of bisection nephrotomy on renal function, size, and morphology in cats. STUDY DESIGN: Controlled, randomized, blinded experiment. SAMPLE POPULATION: Ten adult female cats. METHODS: Glomerular filtration rate (GFR), determined by quantitative renal scintigraphy using (99m)Technetium-diethylenetriamine-pentaacetic acid, urinalysis, urine culture, and ultrasonographic measurement of renal size were performed preoperatively. Left or right nephrotomy (5 cats/group) was performed. Total and individual kidney GFRs were determined at 2, 28, and 84 days, ultrasonographic measurements at 28 and 86 days, and ultrasound-guided biopsy at 86 days. RESULTS: No significant differences in mean GFR and kidney size of operated versus unoperated kidneys were observed. Individual GFR and renal size of all except 1 cat remained within normal limits. Two cats had evidence of transient ureteral obstruction in the immediate postoperative period. No significant, generalized histologic abnormalities were observed. CONCLUSIONS: Bisection nephrotomy in normal cats does not adversely affect renal function or morphology during the initial 12 weeks. CLINICAL RELEVANCE: Bisection nephrotomy can be safely performed in normal feline kidneys without causing a significant deleterious effect on renal function. Studies in cats with pre-existing renal insufficiency are needed to ensure adverse effects would not occur in clinical cases where this surgical procedure is warranted.