Here, we present a protocol for use at the time of transrectal ultrasound guided prostate needle biopsy (TRUS PNB) that is a simple and cost-effective means to reduce infections following the procedure.
Single institution and population-based studies highlight that infectious complications following transrectal ultrasound guided prostate needle biopsy (TRUS PNB) are increasing. Such infections are largely attributable to quinolone resistant microorganisms which colonize the rectal vault and are translocated into the bloodstream during the biopsy procedure. A povidone iodine rectal preparation (PIRP) at time of biopsy is a simple, reproducible method to reduce rectal microorganism colony counts and therefore resultant infections following TRUS PNB.
All patients are administered three days of oral antibiotic therapy prior to biopsy. The PIRP technique involves initially positioning the patient in the standard manner for a TRUS PNB. Following digital rectal examination, 15 ml of a 10% solution of commercially available povidone iodine is mixed with 5 ml of 1% lidocaine jelly to create slurry. A 4 cm x 4 cm sterile gauze is soaked in this slurry and then inserted into the rectal vault for 2 min after which it is removed. Thereafter, a disposable cotton gynecologic swab is used to paint both the perianal area and the rectal vault to a distance of 3 cm from the anus. The povidone iodine solution is then allowed to dry for 2 – 3 min prior to proceeding with standard transrectal ultrasonography and subsequent biopsy.
This PIRP technique has been in practice at our institution since March of 2012 with an associated reduction of post-biopsy infections from 4.3% to 0.6% (p = 0.02). The principal advantage of this prophylaxis regimen is its simplicity and reproducibility with use of an easily available, inexpensive agent to reduce infections. Furthermore, the technique avoids exposing patients to additional systemic antibiotics with potential further propagation of multi-drug resistant organisms. Usage of PIRP at TRUS PNB, however, is not applicable for patients with iodine or shellfish allergies.
Prostate cancer is the most common cancer in men and the second leading cause of cancer-related mortality. In 2014, approximately 233,000 cases will be diagnosed in the United States with almost 30,000 men succumbing to this malignancy.1 While the prostate specific antigen (PSA) blood test and digital rectal examination (DRE) play an essential role in prostate cancer screening, transrectal ultrasound guided prostate needle biopsy (TRUS PNB) is the most common means to obtain a histologic tissue diagnosis.
TRUS PNB involves inserting an ultrasound probe into the patient’s rectum and then generally obtaining 12-14 biopsies of the peripheral zone of the prostate located just anteriorly. Each needle biopsy requires passage of an 18 G needle through the rectal wall into the highly vascular prostate. Therefore, the theoretical risk of bleeding and infection due to bacterial translocation exists following the procedure. Nonetheless, the actuarial complication rate post-procedure has historically remained low.
Antibiotic prophylaxis prior to TRUS PNB is routinely prescribed with quinolone-based antibiotics being the most frequently used agents. Despite adequate prophylaxis, contemporary research implicates an increase in infectious complications post-biopsy.2 Furthermore, studies have attributed this rise in infectious complications following TRUS PNB to the emergence of quinolone resistant microorganisms particularly E. coli.3
This rising rate of quinolone resistance suggests the need for alternate prophylaxis regimens for TRUS PNB procedures. To this end, several different avenues are under investigation. One approach involves administration of an intravenous or intramuscular antibiotic at time of biopsy in conjunction with an oral quinolone.4 While this strategy can reduce sepsis events following TRUS PNB, a principal limitation of this approach is the potential for further developing resistant organisms to this antibiotic family. Another recently investigated methodology incorporates use of a pre-biopsy rectal swab to screen patients colonized with quinolone-resistant rectal flora.5 If such organisms are detected, a “targeted” antibiotic regimen could be employed based on the sensitivity profile of the identified resistant bacterial strain. While the methodology is elegant, the actual process of obtaining such swabs, selectively culturing on a quinolone selective medium, and tailoring antibiotics thereafter requires a clinical and laboratory infrastructure that may be lacking in many clinical practices.
Administration of a topic antiseptic to reduce rectal vault microorganism colony counts prior to biopsy may present an alternative strategy to limit TRUS PNB infections. Povidone iodone is an inexpensive, readily available agent that is documented to reduced bacterial counts when applied to surgical sites. Applications in both colorectal and gynecologic surgeries are well known. Therefore, use of povidine iodine as a rectal preparation would present a producible, simple, and cost-effective method to reduced TRUS PNB infections without need for additional preparation prior to biopsy. With respect to the urologic literature, previously work has noted a reduction in clinical infections following TRUS PNB.6-9 This video demonstrates the technique of PIRP to highlight the ease and simplicity to integrate into clinical practices.
All patients undergoing TRUS PNB were initially seen in a specialty urology clinic for referral or initial evaluation for prostate cancer screening. This evaluation entailed a review of the patient’s serum prostate specific antigen (PSA) and performance of a digital rectal examination (DRE). Abnormality of either the PSA or DRE prompted recommendation of a TRUS PNB.
The TRUS PNB procedure was discussed with all patients and associated risks including infection, bleeding, and urinary retention were clarified. All patients received three days of oral antibiotic prophylaxis with either a quinolone-based medication (i.e., Ciprofloxacin) or trimethoprim-sulfamethoxazole (Bactrim) prior to biopsy.
Infections following TRUS PNB are secondary to translocation of rectal vault bacteria into the highly vascular prostate. Based on this principle, we have explored the simple method of using a topic antiseptic such as povidone iodine to reduce microorganism colony counts prior to prostate needle biopsy. Our experience highlights a reduction from 4.3% to 0.6% (p=0.02) with use of this PIRP regimen at time of biopsy. Furthermore, we hypothesize that the 97% reduction in rectal vault microorganisms is the principle factor un…
The authors have nothing to disclose.
The authors acknowledge the Carefusion Foundation for support via a clinical excellence grant of this work titled “Prospective evaluation of procedural povidone iodine rectal preparation to reduce infectious complications following ultrasound guided prostate needle biopsy.”
Povidone Iodine Solution, 10% Topical Microbicide Antiseptic, 8 fl oz. | Equate | 4067979 | |
4×4 sterile gauze pads, white | Dukal Corporation | DKL1412 | |
disposable gynecologic swab | numerous vendors | ||
1% lidocaine gel | numerous vendors |