The Quarterly Consult is a quarterly publication highlighting pediatric clinical expertise. If you would like to submit questions for a specialist at Children's to address in the Quarterly Consult, contact Kim Arthur, editor.
February 2012: Urology Conditions in Infants and Toddlers
Dr. Paul Merguerian, division chief of Urology at Seattle Children's, addresses questions about urology conditions in male infants and toddlers. Thank you to Dr. Matt Allen, a pediatrician at Ballard Pediatrics and a member of Children's medical staff, for submitting these questions.
Q. It seems we are seeing more newborns with a history of hydronephrosis by prenatal ultrasound. Please clarify the implications of these findings on postnatal urinary tract disease. What is the ideal timing for postnatal renal ultrasound?
A. Prenatal diagnosis of hydronephrosis is very common. Prenatal hydronephrosis is reported in 1% to 5% of all pregnancies and represents a wide variety of urological conditions. The benefits of prenatal diagnosis are prevention of complications from pyelonephritis and preservation of renal function.
As far as postnatal evaluation, our recommendation is to repeat the ultrasound three to seven days after birth and plan follow-up based on the findings of that ultrasound.
If the hydronephrosis is moderate or severe, the patient needs to be referred to Urology. The evaluation will include a voiding cystourethrogram (VCUG) and possibly a renal scan. If it's mild, we suggest repeating the ultrasound three months later.
If the hydronephrosis persists after three months, the patient should be referred to Urology and may require further evaluation with a VCUG and/or a renal scan.
Q. Many asymptomatic infants continue to show pelviectasis or pelvicaliectasis on follow-up ultrasound. When would you recommend repeat ultrasound, VCUG or urology consultation?
A. With mild hydronephrosis, there's no need for a VCUG unless the hydronephrosis persists at 6 months to 1 year of age or if the child develops a urinary tract infection. I would suggest referral to Urology if the hydronephrosis persists.
With moderate or severe hydronephrosis we would recommend a VCUG. Over 30% of these infants will have reflux. The degree of hydronephrosis cannot predict the grade of reflux. If the VCUG is negative, a renal scan to rule out obstruction is recommended.
Q. Could you clarify what the radiologic terms pelviectasis and pelvicaliectasis mean with regard to "mild" or "moderate" hydronephrosis?
A. Hydronephrosis is the general term used for dilatation of the renal collecting system. Pelviectasis (or pyelectasis) means that only the renal pelvis is dilated. Pelvicaliectasis means that both the pelvis and renal calyces are dilated.
Mild hydronephrosis means mild distension of the pelvis and/or calyces.
Moderate means moderate dilatation of the pelvis and calyces (pelvicaliectasis), but usually without thinning of the renal parenchyma. Severe dilatation means severe pelvicaliectasis, usually also with thinning of the renal parenchyma.
We use the Society for Fetal Urology Classification: grade 1 is when urine barely splits the sinus (mild). Grade 2 urine fills the pelvis and the major calyces are dilated (mild). Grade 3 also has dilation of the minor calyces but parenchyma is preserved (moderate). Grade 4 also has parenchymal thinning (severe).
This classification with pictures can be found on this University of Alabama website.
Q. The American Academy of Pediatrics has a neutral policy statement regarding circumcision. Can you summarize the data regarding sexually transmitted diseases (STDs) and circumcision?
A. A good article that summarizes the benefits is Tobian AAR and RH Gray. The Medical Benefits of Male Circumcision. JAMA. Oct 5 2011;306 (13)1479-1480.
Infants who are not circumcised are 10 times as likely to get urinary tract infections compared to infants who are circumcised (1% versus 0.1%).
Some randomized trials in Africa have shown that male circumcision can decrease the acquisition of human immunodeficiency virus (HIV) in men by around 50% to 60%.
Other studies in Africa and New Zealand have shown that male circumcision can reduce the risk of other sexually transmitted diseases, including human papillomavirus (HPV) and bacterial infections, by around 30%.
This suggests that circumcision may have a protective effect in preventing STDs. A concern is that most of these studies were in Africa, where HIV is prevalent, and therefore this may not apply to the United States.
However, in our country, men in some lower socioeconomic backgrounds have a higher incidence of HIV than others in the United States. As an example, the JAMA article states that 7.1% of African American males in Washington D.C. have HIV. So this raises the question whether some disadvantaged populations should be routinely offered neonatal circumcision. Ironically, Medicaid does not cover circumcisions in many states.
The JAMA article also mentions a cost-effectiveness analysis by the Centers for Disease Control and Prevention that found that neonatal male circumcision would increase quality-adjusted life years and result in cost savings because of a reduction in HIV infections and treatment costs.
Q. Many parents are troubled by their son's "hidden penis" in the first couple years of life. How should primary care physicians differentiate between a benign suprapubic fat pad and a buried penis needing intervention?
A. If the pediatrician is able to push the suprapubic fat pad and expose the penis, then they should not be worried because it will usually resolve with time. If they are not able to do so, then the patient should be referred to Urology for potential surgical repair.
If the buried penis is causing issues with voiding or irritation, then a referral to Urology for possible correction would be appropriate.
Q. Phimosis is a complication for a minority of uncircumcised boys. What are the indications for topical steroids and urologic surgical intervention?
A. If the phimosis persists after 5 years of age, I would recommend topical steroids. It's important to make sure they are applied correctly. We use betamethasone cream and we ask the parents to pull the skin back and apply the cream around the tight ring twice daily and try to pull the skin back until it's completely retracted.
We usually recommend treatment for six to eight weeks, and if the steroid cream doesn't work, then we would recommend circumcision. If parents are against a circumcision, we would recommend a preputial plasty or dorsal slit.
Q. Children's has recently developed a urinary tract infection (UTI) pathway (guideline). Can you share any resources regarding treatment, prophylaxis and work-up for UTIs?
A. Yes, Children's new UTI pathway, which is based on a systematic and comprehensive review of the literature, is available on the Clinical Standard Work Pathways and Tools site. Highlights include:
- Given the extremely high false-positive rate, bag specimens should not be used to make the diagnosis of UTI in nontoilet-trained children (cath or suprapubic aspiration only).
- When presenting with urinary complaints, adolescents should have a documented external genitourinary (GU) exam as well as urine testing for concurrent GC/Chlamydia infection.
- For empiric oral therapy, cephalexin remains a preferred first-line antibiotic choice, with cefuroxime serving as a reasonable alternative. For more information about the rationale for using cephalexin, please see last month's article about the UTI pathway.
- When a patient improves clinically, do not routinely perform a follow-up urine culture for test of cure.
- Do not routinely perform a VCUG. VCUG is indicated for abnormal ultrasound findings or atypical UTI (see pathway algorithm for definition of atypical UTI and details on VCUG indications).
- For patients with first-time UTI in whom VCUG is indicated, do not routinely prescribe antibiotic prophylaxis for those found to have low-grade (I to III) vesicoureteral reflux.