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1154 Prostatic Diagnostic Sampling

Anticipated Time • Material is aspirated into the needle by out of the penis but moves forward into the
bladder.
• Abdominal ultrasound takes 10-40 minutes, drawing on the syringe plunger to create • Another 5 mL of sterile saline is injected
VetBooks.ir • FNA takes about 5 minutes. • Negative pressure is released before withdraw- into the catheter. The fluid flows across the
depending on operator expertise.
negative pressure in the syringe.
• Automated needle biopsy with anesthesia,
prostatic urethra into the bladder.
ing the needle.
prostatic massage, or diagnostic catheteriza-
tion takes 20-30 minutes. • The needle and syringe are then withdrawn • The catheter is then pushed into the bladder,
quickly, the syringe is detached from the
and the fluid is aspirated into a syringe and
needle and filled with air, and the syringe placed into a sterile tube labeled tube #2.
Preparation: Important is reattached to the needle. The contents Both tubes are presented for fluid analysis
Checkpoints are vigorously expelled onto a microscope and culture.
• Lateral or dorsal recumbency slide to make fresh smears for cytologic • Sample #1 will have only bladder material,
• These procedures usually require the attend- evaluation. whereas sample #2 will have both prostate
ing veterinarian and one or two assistants. • A portion of the material can be placed in and bladder material. Comparing the two
• Needle aspiration can be performed on a appropriate media for culture and susceptibil- samples allows the clinician to localize the
fully awake animal, provided the animal is ity (C&S) testing instead of being smeared, disease process to the prostate and/or the
adequately restrained. or the procedure can be repeated to obtain urinary bladder.
• Automated needle biopsies require heavy more material for this purpose. Diagnostic catheterization:
sedation with analgesia or general anesthesia. FNA, guided: • Prepare the penis, and empty the bladder as
• For prostatic massage and diagnostic • The animal should undergo a full above.
catheterization, digital rectal palpation and abdominal ultrasound evaluation, and an • The urinary catheter is placed into the
urethral catheterization are necessary. If the appropriate area for aspiration should be prostatic urethra. Correct catheter placement
patient resists these procedures, sedation is identified. can be verified by digital rectal examination
advised. • The skin is clipped of hair and aseptically or by ultrasound.
• A soft red rubber (Sovereign type) feeding prepared with surgical scrub. • A 60-mL syringe is attached to the end of the
tube is less traumatic than a polypropylene • The needle with a syringe attached is then catheter, and negative pressure is applied so
catheter. advanced through the skin into the prostate that prostate tissue is aspirated into the holes
under ultrasound guidance. of the catheter. Quickly pull the catheter
Possible Complications and • The prostate gland is aspirated, and the back and forth within the urethra at the
Common Errors to Avoid sample is handled for evaluation (as level of the prostate gland while suction on
• FNA and automated needle biopsy proce- described). the 60-mL syringe is maintained. This tears
dures require the placement of a needle or Automated needle biopsy: tissue from the prostate gland that is aspirated
biopsy instrument directly into the prostate. • Automated needle biopsies (guided or into the catheter.
Adjacent large vessels such as the distal nonguided) are attained as described above • While maintaining negative pressure on the
abdominal aorta and caudal vena cava can for needle aspiration. Because this is a more syringe, remove the catheter from the urethra.
be lacerated with patient movement or a invasive and painful procedure, general This prostatic tissue can be evaluated by
biopsy miss. anesthesia is recommended. cytologic evaluation, and sometimes a large
• These procedures should not be performed on • Care must be taken not to transect the enough piece is obtained for histopathologic
animals with inadequate coagulation systems. urethra with this full-thickness biopsy evaluation.
• If acute bacterial prostatitis (p. 827) is procedure. With this in mind, the biopsy
present, prostatic massage can result in should be taken in an orientation angled Postprocedure
release of bacteria into the bloodstream and away from the urethra, not perpendicular • These are outpatient procedures, and the
septicemia. to the urethra. client may be sent home the same day
• Diagnostic catheterization and automated • A portion of the biopsy is taken for culture. provided that its clinical condition allows.
needle biopsy may lacerate the urethra. The biopsy is then rolled on a slide for cyto- • The patient should be sent home on an
• If an abscess or cyst is present, rupture is logic analysis. The sample is then placed in antibiotic if bacteria are identified from urine
possible secondary to all of these procedures. formalin and processed for histopathologic or prostate pending culture and susceptibility;
• With prostatic neoplasia (particularly tran- examination. antibiotics with adequate prostatic penetra-
sitional cell carcinoma [pp. 828 and 991]), Prostatic massage: tion should be used (e.g., enrofloxacin).
there is a risk of tumor seeding along needle • The tip of the penis is extended from the • The client should be counseled that there may
or biopsy tract. prepuce and cleaned with a mild disinfectant. be hematuria transiently after the procedure.
• A urinary catheter is placed into the bladder,
Procedure and the urine is completely removed. Alternatives and Their
Relative Merits
• Sterile saline (5 mL) is instilled into the
FNA, nonguided: bladder. This fluid is then aspirated and A technique for performing a needle aspira-
• If the prostate is sufficiently enlarged that it placed in a sterile tube labeled tube #1. tion biopsy of the prostate per rectum using
can be palpated externally (abdominally) and • The veterinarian then places an index finger a guarded needle has been described. This
stabilized by caudal abdominal palpation, the in the rectum and palpates the prostate and technique has the problem of injecting bacteria
procedure can be performed without the use the catheter. The catheter is retracted until directly into the prostate because the colon
of ultrasound (nonguided). the tip can be felt caudal to the prostate. cannot be sterilized. The advent of ultrasound-
• The external surface of the skin overlying the Ultrasound can also be used for confirming guided techniques has made this procedure
region of the enlarged prostate is clipped of catheter placement at the level of the prostate obsolete.
hair and aseptically prepared with surgical gland. The prostate is then massaged for 1
scrub. minute. Pearls
• The needle is affixed to the syringe, the • The palpating finger is retracted until it is • Diagnostic catheterization is easier if the
needle tip is placed through the prepared caudal to the holes in the catheter. Pressure patient is sedated.
skin, and the tip is advanced into the prostate is applied to the catheter rectally so that • These nonsurgical biopsy techniques have made
gland. fluid injected into the catheter does not leak surgical biopsy techniques almost obsolete.

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