Research Article: Antibiotic Prophylaxis with Trimethoprim-Sulfamethoxazole versus No Treatment after Mid-to-Distal Hypospadias Repair: A Prospective, Randomized Study

Date Published: March 26, 2018

Publisher: Hindawi

Author(s): Elizabeth B. Roth, John V. Kryger, Charles T. Durkee, Melissa A. Lingongo, Ruth M. Swedler, Travis W. Groth.


To evaluate the impact of prophylactic antibiotics after distal hypospadias repair on postoperative bacteriuria, symptomatic urinary tract infection, and postoperative complications in a prospective, randomized trial.

Consecutive patients aged 6 months to 2 years were enrolled at our institution between June 2013 and May 2017. Consenting patients were randomized to antibiotic prophylaxis with trimethoprim-sulfamethoxazole versus no antibiotic. Patients had catheterized urine samples obtained at surgery and 6–10 days postoperatively. The primary outcome was bacteriuria and pyuria at postoperative urine collection. Secondary outcomes included symptomatic urinary tract infection and postoperative complications.

70 patients consented to the study, of which 35 were randomized to receive antibiotics compared to 32 who did not. Demographics, severity of hypospadias, and type of repair were similar between the groups. Patients in the treatment group had significantly less pyuria (18%) and bacteriuria (11%) present at stent removal compared to the nontreatment group (55% and 63%; p=0.01 and p < 0.001, resp.). No patient had a symptomatic urinary tract infection. There were 11 postoperative complications. Routine antibiotic prophylaxis appears to significantly decrease bacteriuria and pyuria in the immediate postoperative period; however, no difference was observed in symptomatic urinary tract infection or postoperative complications. Clinical Trial Registration Number NCT02593903.

Partial Text

Hypospadias occurs in at least 1/300 live births [1], making it one of the most common entities treated by pediatric urologists. A 2010 report of practice patterns among pediatric urologists in North America showed that >90% place patients on routine antibiotic prophylaxis after single-stage hypospadias repair requiring use of a urethral stent [2]. As such, this represents a significant utilization of antibiotics in the pediatric urology practice. While antibiotic prophylaxis has been extensively studied in patients with other urologic conditions, including hydronephrosis and vesicoureteral reflux, less is known about the efficacy and necessity of antibiotic prophylaxis in the setting of hypospadias repair.

After approval by our institutional review board, we prospectively enrolled patients between 6 months and 2 years of age with mid-to-distal shaft hypospadias scheduled for elective primary hypospadias repair at our institution between June 2013 and May 2017. Children with proximal hypospadias or a history of previous hypospadias repair were excluded, as were children with allergies to trimethoprim-sulfamethoxazole (TMP-SMX). Children were randomized into treatment (TMP-SMX prophylaxis at 3 mg/kg trimethoprim daily) versus nontreatment. Simple randomization using a random number generator was used to assign patients to treatment versus nontreatment groups. Surgeons were not aware of the patient’s randomization at the time of surgery, and the surgical technique was not standardized. Patients did not routinely receive IV antibiotics perioperatively, and the treatment group was instructed to begin TMP-SMX on the evening of surgery and continue until the evening prior to catheter removal in the clinic. Postoperative care was standardized for all patients utilizing the same 6 Fr Kendall-type hydrophilic urethral stent (Covidien Dover Hydrogel Coated Urethral Catheter 6 Fr #6006) and double diaper urinary drainage for 6–10 days following surgery. All children had urine samples obtained intraoperatively and at the first postoperative clinic visit prior to catheter removal. Patients in the treatment group were asked to return study medication at their first postoperative clinic visit, and residual TMP-SMX was measured to assess compliance with the regimen.

Of 113 consecutive eligible patients, 70 consented to the study. Thirty-five were randomized to receive TMP-SMX prophylaxis at 3 mg/kg daily, and 32 received no antibiotics. Three patients who enrolled in the study were unable to be randomized, one due to finding a proximal hypospadias during reexam under anesthesia at the time of operative repair and two due to lack of pharmacy support to provide the study drug should they be randomized to treatment with TMP-SMX. One patient in the nontreatment group had bacteria present on urinalysis in the OR and was excluded from further analysis (Figure 1).

While it remains common practice among pediatric urologists, the use of perioperative and postoperative antibiotics in hypospadias has not been well characterized in terms of postoperative urine studies or in terms of clinical outcomes. In the absence of true evidence-based guidelines, most providers rely heavily on tradition and on clinical pathways learned during residency and fellowship training when determining whether or not to give antibiotics in this situation.

In a prospective, randomized study of prophylactic antibiotics versus no antibiotics in patients undergoing mid-to-distal hypospadias repair with postoperative urethral stent, patients treated with TMP-SMX at 3 mg/kg/day experienced significantly lower rates of bacteriuria and pyuria at 6–10 days postoperatively than patients not treated with antibiotics. Additionally, organisms cultured from children on prophylaxis were significantly more likely to be resistant to the prophylactic agent. Despite this significant difference, no clinical differences between symptomatic UTI and postoperative complications were observed between the groups. Although limited by sample size and protocol deviation, our study lends credence to the growing body of literature that suggests that postoperative prophylaxis may not improve clinical outcomes in patients undergoing uncomplicated single-stage mid-to-distal hypospadias repair. Further study, likely a multi-institutional prospective trial, is indicated to determine if these outcomes are truly similar over a longer period of time.




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