Ultrasound-guided biopsy

Ultrasound-guided biopsy is a good and feasible technique in dogs. Although we have only used it for biopsy of liver and kidney, it can have further uses. In our use of ultrasound-guided biopsy of kidney and liver, we have found that we can achieve adequate biopsy samples using the Franklin modified Vim-Silverman and Tru Cut biopsy of kidney and liver. The fine-needle biopsies of the liver were adequate for examination of hepatocytes but inadequate to evaluate structure owing to small size of the sample. In contrast, the renal fine-needle samples were both poor in quality and quantity. This technique has the advantages of being noninvasive, quick, and easy, and it can be performed with the patient under local anesthesia. It has an advantage over blind percutaneous biopsy because the needle can be visualized in the organ and the organ scanned after biopsy for possible complications. Another advantage is that, unlike other radiographic biopsy procedures, ionizing radiation is not used for imaging.     

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.     

ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION BIOPSY OF BONE LESIONS: A PRELIMINARY REPORT

The purpose of this preliminary study was to determine the feasibility of ultrasound-guided fine-needle aspiration biopsy of suspected neoplastic lesions of bone. Ultrasound-guided fine-needle aspiration biopsy samples were obtained in 23 patients (22 dogs and one cat) with radiographic evidence of a destructive or destructive/productive bone lesion. The lesions were located in the appendicular skeleton in 20 patients and in the axial skeleton in three. Histopathology from tissue core biopsies and/or necropsy was not deemed necessary in 11 patients where ultrasound-guided fine-needle aspiration biopsy results were conclusive for neoplasia. A cytologic diagnosis from ultrasound-guided fine-needle aspiration biopsy was confirmed by histologic samples obtained at surgery or necropsy in five patients. In one of these five, ultrasound-guided fine-needle aspiration biopsy samples were diagnostic for sarcoma when tissue-core biopsy was inconclusive. Both ultrasound-guided fine-needle aspiration biopsy and tissue core biopsy techniques were inconclusive in one patient. Ultrasound-guided fine-needle aspiration biopsy samples were nondiagnostic in five patients where a follow-up histopathologic diagnosis of neoplasia was made. It was concluded that ultrasound-guided fine-needle aspiration biopsy of bone, if diagnostic, may help avoid the need for a tissue-core biopsy in some instances. However, a negative ultrasound-guided fine-needle aspiration biopsy sample does not rule out neoplasia. A negative ultrasound-guided fine-needle aspiration biopsy should be followed by a tissue-core biopsy and histologic analysis in all patients. Ultrasound-guided fine-needle aspiration biopsy seems to be a promising technique for the diagnosis of bone lesions.     

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.     

Evaluation of hemorrhage, sample size, and collateral damage for five hepatic biopsy methods in dogs

OBJECTIVES: To compare the volume of hemorrhage, number of lobules, and portal triads available for histologic evaluation, and resultant collateral damage between 5 hepatic biopsy methods: biopsy punch, biopsy needle, ligature method, laparoscopic biopsy forceps, and ultrasonically activated scalpel (UAS). STUDY DESIGN: Experimental, repeated measures, block. ANIMALS: Twelve adult dogs. METHODS: Biopsies were obtained from the periphery and center of the left lateral liver lobe of each dog using each of 5 biopsy techniques. Hemorrhage was quantified and compared between methods and sites. Biopsy samples were evaluated histologically to characterize collateral damage and determine the number of lobules and portal triads sampled. RESULTS: Regardless of technique, liver biopsy resulted in minimal hemorrhage (<2 mL). For peripheral biopsies, UAS was comparable with the ligature method, but caused significantly less hemorrhage than all other methods, whereas for central biopsies, UAS caused significantly less hemorrhage than other methods. Except for the laparoscopic biopsy forceps, UAS caused significantly more collateral damage than other methods. UAS and ligature biopsy methods yielded specimens that had more portal triads per sample than other methods. Eight of 48 biopsy needle samples were inadequate for histologic evaluation, whereas other methods yielded adequate specimens. CONCLUSIONS: All biopsy methods produced minimal hemorrhage and except for needle biopsy yielded adequate tissue samples for histologic evaluation. CLINICAL RELEVANCE: Use of UAS is a reliable, safe alternative technique for liver biopsy and can be used laparoscopically to obtain large tissue samples.     

Gastrointestinal endoscopic surgery.

A working knowledge of normal endoscopic anatomy and the effects of positioning must be mastered to take advantage of endoscopic procedures involving the gastrointestinal system. Endoscopic procedures involving the gastrointestinal system offer advantages over conventional surgery in that they are less invasive and provide direct visualization. Laparoscopy can be used to evaluate horses with abdominal pain before and after surgery. It can be used to evaluate and biopsy abdominal masses and parenchymal organs such as the spleen, liver, and kidney. Endoscopic gastrointestinal surgical procedures such as colopexy and adhesionolysis are limited at this time but should continue to be developed as instrumentation and technology evolve.     

Getting to the point: indications for fine-needle aspiration of internal organs and bone

The technique of fine-needle biopsy (fine-needle aspiration or fine-needle fenestration) for cytologic evaluation can be extended to many sites beyond the traditional lymph node and skin. Intra-abdominal, intrathoracic, and bone lesions can be easily and rapidly evaluated cytologically. Percutaneous fine-needle aspiration and fine-needle fenestration are useful, accurate, and inexpensive techniques with a rapid turnaround time, and outpatient applicability. For most pets, these minimally invasive techniques do not require anesthesia or analgesia. Although risks are inherent with any invasive procedure, complications are uncommon even with visceral and intrathoracic fine-needle biopsy. Attention to appropriate technique and close patient monitoring minimize the morbidity and improve the diagnostic utility. The low cost, low risk, minimal invasiveness, and high diagnostic yield make fine-needle biopsy particularly attractive to clients. In combination with ultrasound guidance and newer staining techniques, these diagnostic procedures are invaluable to the veterinary clinician.     

Isobaric (gasless) laparoscopic liver and kidney biopsy in standing steers

The purpose of the current study was to investigate the suitability of an isobaric laparoscopic procedure, using a single port, for obtaining serial kidney and liver biopsy samples from standing steers. The samples were used in support of a pharmacokinetic tissue–fluid correlation study. Laparoscopic access was performed 3 times in each of 8 healthy Holstein steers, alternating from the right side to the left side and then to the right side again. The surgery was performed in standing stocks after the animals were given 3 doses of sulfadimethoxine sulfate intravenously and fasted for at least 18 h. Sedation and analgesia were achieved with acepromazine and xylazine. Lidocaine 2% was injected at the center of the paralumbar fossa (left or right), and an incision was made for introduction of a trocar–cannula assembly. Room air was allowed to enter the abdomen through the cannula at the time of insertion. Once the peritoneal cavity was reached, an operating endoscope was inserted. No pressurized insufflation was performed. A biopsy forceps was introduced into the operating channel of the endoscope to obtain a 100-mg kidney or liver sample. No complications were encountered. The 24 laparoscopic procedures provided 24 kidney and 16 liver samples. The results suggest that the isobaric (gasless) single-port laparoscopic technique is feasible for kidney and liver biopsy on standing steers. The procedure can be performed in a reliable and efficient manner in the sedated standing bovine.     

Measurement of the status of trace elements in cattle using liver biopsy samples

Serum, plasma, or urine samples are usually used for the measurement of the trace elements copper; zinc, iron, selenium, because these samples are easy to obtain; however; these samples are not always appropriate. For example, it is not possible to measure molybdenum, the major antagonist of copper; in blood or urine. Therefore measurement of trace elements in liver tissue is considered the gold standard. For the assessment of selenium the method of choice remains determination of glutathion peroxidase in erythrocytes and for the assessment of magnesium determination of magnesium in urine. We determined the accuracy and repeatability of measuring trace elements in liver biopsies and whole liver homogenates. The levels of trace elements measured were similar in both preparations (92% agreement). Liver biopsy in live animals is a relatively simple procedure but not common in The Netherlands. Reference levels of trace elements, classified as too low, low, adequate, high, and too high, were established on the basis of our research and information in the literature. In a second study we investigated the practical aspects of obtaining liver tissue samples and their use. Samples were collected from cattle on a commercial dairy farm. Liver biopsy provided additional information to that obtained from serum and urine samples. We prepared a biopsy protocol and a test package, which we tested on 14 farms where an imbalance of trace minerals was suspected. Biopsy samples taken from 4 to 6 animals revealed extreme levels of trace elements.     

Lymph node cytology.

Lymph node cytology is quick, easy, and rewarding. Cytologic samples of peripheral and/or internal lymph nodes may be collected by fine-needle aspiration biopsy (FNAB) or nonaspiration fine-needle biopsy techniques. In addition, imprints or scrapings may be made from lymph nodes that have been surgically removed or at necropsy. Lymph node cytology is an excellent way to evaluate a lymphadenopathy whether it is a single node enlarged, multiple nodes enlarged, or a generalized lymphadenopathy. If multiple lymph nodes are enlarged, more than one should be sampled. A lymph node away from the mouth or any site of inflammation should be aspirated as well as any lymph node close to a site of inflammation. Generally, if no lymph nodes are enlarged, lymph node cytology is not helpful.     

ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION

A simple and inexpensive modification of the ultrasound-guided fine-needle aspiration biopsy technique using an extension tube attached to the needle is described. One operator can easily manipulate the ultrasound transducer and biopsy needle while monitoring the entire procedure. This simple modification was found to facilitate ultrasound-guided fine-needle aspiration.     

Detection of fibrin deposits in horse tissues by immunohistochemistry

BACKGROUND: Histochemical and immunohistochemical techniques have been used to detect fibrin deposits in different tissues in humans and experimental animal models with disseminated intravascular coagulation (DIC). Fibrin deposits also have been observed in horses with severe ischemic and inflammatory disorders by histochemical stainings (phosphotungstic acid hematoxylin [PTAH]). HYPOTHESIS: Immunohistochemical (IHC) methods can be used to accurately detect fibrin deposits in horses at risk of DIC. ANIMALS: Tissue-organ samples collected on postmortem examination from 87 horses with severe inflammatory and ischemic gastrointestinal disorders. In addition, tissue samples from 13 horses with colic and colonic obstructions or displacements and from 13 slaughter horses were used as controls. METHODS: Tissue samples (kidney, lung, and liver) were stained with PTAH and IHC for blinded histologic examination and comparison. A fibrin score (grades 0 to 4) was established for each tissue sample and for each horse for both techniques. RESULTS: When the IHC method was used, fibrin deposition was observed in 47.1% of the horses with colic with a poor prognosis, compared with 41.4% with PTAH. An agreement of 70% was achieved when both methods were compared, and the lung was confirmed as the most affected organ. Almost none of the colic and slaughter control horses had fibrin deposits in their tissues. CONCLUSIONS AND CLINICAL IMPORTANCE: IHC technique for fibrin antigens was very effective in the detection and identification of fibrin deposits in equine tissues and may be a reliable technique for the postmortem diagnosis of DIC.     

A COMPARISON OF MANUAL AND AUTOMATIC ULTRASOUND-GUIDED BIOPSY TECHNIQUES

A manual, ultrasound-guided biopsy technique was compared to a new automatic method using a new biopsy device. The liver and the left kidney of 10 dogs were biopsied using the two methods. The specimens from the biopsies were compared for size and quality. Results demonstrate that larger and higher quality samples were obtained with the new automatic method.     

Muscle biopsy using the muscle punch--removal technique, transport and evaluation ability

Histopathological striated muscle examination is one of the most important and sensitive tests in diagnosis of muscle and/or nerve diseases. Although muscle biopsy is a relatively easy procedure, it is not frequently performed in small animal practice conditions. Different biopsy techniques have been described in veterinary literature. Punch biopsy of striated muscle appears to be a less invasive and quicker method in comparison with traditional surgical excision technique. Additionally, punch biopsy provide good quality and adequate amount of muscle tissue for diagnostic histopathological evaluation. The aim of this study is to describe striated muscle punch biopsy technique and to encourage use of it under the conditions of small animal practice. The described biopsy method can be specially advantageous in screening of inherited muscle diseases in affected litters or even wider animal population.     

ULTRASOUND-GUIDED BIOPSY OF THE CANINE LIVER, KIDNEY, AND PROSTATE

Sixty-nine hepatic, 25 renal, and 16 prostatic biopsies were performed under ultrasound guidance using a biopsy guide. The majority (98 of 110) were tissue-core biopsies. Multiple attempts at obtaining a sample were required; however, in the kidney, the number of attempts was restricted to two. Adequate samples were obtained in 94% (65/69) hepatic, 88% (22/25) renal, and 94% (5/6) prostatic biopsies. Postbiopsy scanning did not demonstrate parenchymal hemorrhage. In three renal and one prostatic biopsy, gross hematuria, noted immediately following biopsy, resolved in 2–3 days. Animals with prostatic disease frequently had hematuria, making evaluation for this complication difficult. One animal died acutely 2 days following prostatic biopsy due to an unrelated problem, a ruptured aortic àneurysm. Complications were not encountered with the liver biopsy procedure. Animals biopsied under sedation tolerated the procedure well. The authors preferred to anesthetize uncooperative animals and those needing kidney biopsy to minimize the likelihood of complications. Problems encountered during the procedure, overlying bowel gas obscuring the target organ or poor visualization of the biopsy needle, were corrected by changing patient or transducer position or the procedure was postponed. The usefulness of the biopsy procedure is illustrated in four case reports.     

Computed tomography-guided fine-needle aspiration and tissue-core biopsy of bone lesions in small animals

In humans, free-hand computed tomography (CT)-guided biopsy is an accurate method to obtain a tissue sample. There are only a few reports of this technique in veterinary medicine. In the present study, 21 dogs and two cats underwent a free-hand CT-guided tissue-core biopsy (17 animals) or fine-needle aspiration (six animals) of a bone lesion. Two out of 17 tissue-core samples were also cultured. All 17 tissue-core biopsy samples were diagnostic (accuracy of 100%). Five out of six aspirates were diagnostic (accuracy of 83.3%). The overall accuracy was 95.7%. In one aspirate, cytologic quality was insufficient containing only blood. No major complications were encountered. Fourteen neoplastic, two infectious and six benign lesions were diagnosed. CT examination after intravenous contrast medium added useful information to avoid large vessels and to biopsy-viable tissue. Free-hand CT-guided tissue-core biopsy and aspiration appears to be a safe and very accurate procedure for use in the diagnosis of bone-associated diseases in small animals.     

Comparison of renal biopsy techniques in dogs

To evaluate adequacy of biopsy specimens obtained and safety to the patient, the standard keyhole biopsy technique (using digital immobilization of the right kidney and placement of the biopsy needle up to the capsule before obtaining a tissue sample) was compared with 9 technical modifications. Adequacy was judged by the number of intact glomeruli observed in the specimen. Detection of transected blood vessels and renal pelvis was presumed to have predictive value for postbiopsy complications of hemorrhage and hydronephrosis. Needle biopsy specimens were also obtained from left and right kidneys by use of laparoscopic visualization and were compared with those obtained by use of the standard keyhole technique. Although the standard keyhole technique yielded the highest percentage of adequate biopsy specimens, there was no statistical difference between specimens obtained by this technique and those obtained by the modified technique or by laparoscope-guided biopsy. Also, significant difference in percentage of biopsy specimens with renal pelvis was not found between specimens obtained by the standard and modified techniques. For each technique, the biopsy core length was measured and the mean value was calculated. In this study, core length did not correlate with adequacy of the biopsy specimen.     

Rabbit Clinical Pathology

With rabbit patients, as in other species, analyzing blood and urine samples can be useful and informative, although interpretation of the results is sometimes challenging. This article summarizes the interpretation of laboratory results from rabbits. Hematological parameters can yield information about the red blood cell population and leukocyte response to stress and pathogens. Biochemistry evaluation can be used to investigate liver, kidney, and other organ function, and urinalysis results may yield additional information about kidney function and electrolyte imbalances. Serological tests are available for several pathogens of rabbits, including Encephalitozoon cuniculi, although the significance of positive results and antibody titers is not clear. Serum protein electrophoresis aids the understanding of protein disorders and the immune response to acute and chronic inflammation.     

Validation of a transendoscopic glandular and nonglandular gastric biopsy technique in horses

Reasons for performing study: In order to study the evolution of histopathological and immunohistochemical changes in the gastric mucosa of horses with EGUS (equine gastric ulcer syndrome), a feasible, useful, valid and safe in vivo gastric biopsy technique is required. Objectives: To determine the average gastric mucosal healing time following endoscopic gastric biopsy sampling, and evaluate the feasibility, safety and usefulness of samples obtained by this method for histopathological analysis. Methods: Six mature mares from the Faculté de Médecine Vétérinaire research herd were used. Transendoscopic gastric biopsy was performed on Days 0 and 9 using a flexible forceps with oval and fenestrated jaws to obtain gastric mucosal samples from 4 different sites: cardia (C), fundus (F), margo plicatus (MP) and glandular mucosa (GL). A maximum of 4 samples per site was taken and processed routinely for histopathology, evaluated by a pathologist. On Days 1–4 and 9–11 the lesions created by the biopsies were evaluated by gastroscopy. Lesions were evaluated over time based on a score from 0–4, where 4 was the most severe. Results: Biopsy samples could be obtained from all targeted sites except C. No abnormal clinical signs were observed up to 7 days post biopsy. The average biopsy lesion scores decreased significantly with time for all sites. The average lesion score was significantly higher for the MP compared to the other sites at Days 1 and 2. Samples taken from the nonglandular portion of the stomach were considered inadequate for histopathology, while those taken from the glandular mucosa were adequate. Conclusion: The transendoscopic gastric biopsy technique described here is a feasible, safe and useful technique for obtaining samples from the equine gastric glandular mucosa. Although biopsy samples could be obtained from several areas in the nonglandular mucosa, these were very small, took longer to heal and were not considered adequate for histopathological evaluation, and another technique should therefore be validated.     

Comparison of core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes for antemortem diagnosis of enzootic bovine lymphosarcoma in cattle

OBJECTIVE: To determine whether antemortem core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes could be used to distinguish between inflammation and lymphosarcoma in cattle. DESIGN: Prospective study. ANIMALS: 25 cattle with enlarged peripheral lymph nodes. PROCEDURES: Antemortem biopsies of the selected lymph nodes were performed with an 18-gauge, 12-cm core needle biopsy instrument. Fine-needle aspirates were performed with a 20-gauge, 4-cm needle. Specimens were analyzed by pathologists who were unaware of clinical findings and final necropsy findings, and specimens were categorized as reactive, neoplastic, or nondiagnostic for comparison with necropsy results. RESULTS: Sensitivity and specificity of core needle biopsy ranged from 38% to 67% and from 80% to 25%, respectively. Sensitivity of fine-needle aspiration ranged from 41% to 53%, and specificity was 100%. Predictive values for positive test results ranged from 77% to 89% for core needle biopsy and were 100% for fine-needle aspiration. Predictive values for negative test results were low for both core needle biopsy and fine-needle aspiration. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that core needle biopsy and fine-needle aspiration can aid in the antemortem diagnosis of bovine enzootic lymphosarcoma. Results of fine-needle aspiration of enlarged peripheral lymph nodes were more specific and more predictive for a positive test result than were results of core needle biopsy.