Transrectal ultrasound–guided biopsy is considered the standard approach for prostate biopsy and is most commonly performed on an outpatient with a positive screening for prostate cancer.
Nowadays, with the MRI capacity for depicting abnormal areas of the prostate, is possible to obtain targeted sampling of prostate lesions with the use of real-time MR imaging–guided prostate biopsy.
Prostate cancer screening consists of PSA concentration in serum and a digital rectal examination. Positivity in one of these tests make patients candidates for further diagnostic evaluation with a transrectal ultrasonography–guided prostate biopsy.
The contraindications must be considered individually in each case. Overall, the most important contraindication are:
- uncooperative patient
- sedation with a hypnotic agent (eg. propofol or midazolam) could be performed and monitored by an anesthesiologist.
- uncorrectable bleeding diathesis (abnormal coagulation indices)
Antibacterial prophylaxis are recommended and may follow institutional protocols. The recommended antibiotics for transrectal prostate biopsies made by american urology association include: quinolones, 1st / 2nd / 3rd generation cephalosporins,aminoglycoside + metronidazole or clindamycin, and aztreonam +metronidazole or clindamycin.
Some institutions standardized a small enema before the procedure to clean out bowels and clear the rectum of feces. Evidence shows that there was no significant difference in rates of infectious complications between patients submitted or not to bowel preparation if they are on antibacterial prophylaxis4.
Laboratory parameters for a safe procedure
Many patients that underwent prostate biopsy have increased cardiovascular risk and make continued use of anticoagulants or antiplatelet therapy. The decision to suspend or maintain these therapies must be taken together with the patient's physician, taking into account the risks of bleeding and of a cardiovascular event.
In patients without disease or use of drugs that cause bleeding diathesis, pre-procedure laboratory exams may not be necessary. Although, some institutional protocols and some specific cases could demand for a blood test.
Complete blood count - Platelet > 50000/mm2 (Some institutions determine other values between 50000 -100000/mm3)2
Coagulation profile: Some studies showed that having a normal INR or prothrombin time is no reassurance that the patient will not bleed after the procedure.
- international normalized ratio (INR) ≤ 1.5 2
- normal prothrombin time (PT), partial thromboplastin time (PTT)
Patient may be positioned in the left lateral decubitus with semi-flexed knees.
- The ultrasound transducer is inserted into the patient’s rectum. Lidocaine gel may be used as ultrsound gel.
- Regional block is administered around both neurovascular bundles (lidocaine).
- Biopsy needle is introduced. US–guided prostate biopsy is not a targeted biopsy procedure. The prostate sampling technique is based on the sextant protocol, described by Hodge et al. and modified later, in which samples were obtained of the more peripheral zone (where the diagnostic yield is higher) from the base through the middle to the apex of the gland, bilaterally. Usually are 12 samples, two per sextante.
The recovery process will vary depending on the type of anesthesia that is used. In the usual technique, with only local anesthetic, the patient can resume your normal activities and diet.
Patient should be instructed about some light bleeding from his rectum. That he may note blood in urine or stools for a few days and his semen may have a red or rust-colored tint caused by a small amount of blood.
It should be reemphasized the continued use of antibiotic, as institutional protocols.
Minor complications are frequent, such as limited hematuria and hematospermia (may persist as long as 1 week after the biopsy). Reported infection rates are variable but low with the use of prophylactic antibiotics (Septicemia requiring hospitalization occurred in less than 4% of patients1).
- 1. Yacoub JH, Verma S, Moulton JS et-al. Imaging-guided prostate biopsy: conventional and emerging techniques. Radiographics. 2012;32 (3): 819-37. doi:10.1148/rg.323115053 - Pubmed citation
- 2. Walker TG. Interventional Procedures. Lippincott Williams & Wilkins. (2012) ISBN:1931884862. Read it at Google Books - Find it at Amazon
- 3. El-Hakim A, Moussa S. CUA guidelines on prostate biopsy methodology. Can Urol Assoc J. 2011;4 (2): 89-94. Free text at pubmed - Pubmed citation
- 4. Zaytoun OM, Anil T, Moussa AS et-al. Morbidity of prostate biopsy after simplified versus complex preparation protocols: assessment of risk factors. Urology. 2011;77 (4): 910-4. doi:10.1016/j.urology.2010.12.033 - Pubmed citation
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