This Month in Pediatric Urology

Article Outline

• Superficial Genitourinary Abscesses in Children
• Genotype and Phenotype in Patients With Complete Androgen Insensitivity Syndrome
• Open Versus Laparoscopic Pediatric Pyeloplasty
• Urinomas Associated With Posterior Urethral Valves
• Copyright

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Superficial Genitourinary Abscesses in Children 

Methicillin resistant Staphylococcus aureus (MRSA) had been considered an acquired nosocomial infection. However, community acquired MRSA is now recognized as the most common pathogen of genitourinary soft tissue abscesses. Alt et al (page 1472) from Rochester, Minnesota describe the shift in pathogens causing genitourinary abscesses. They retrospectively reviewed all records of pediatric patients undergoing surgical debridement of an abscess from 1995 through 2007. Only patients younger than 18 years were included in the study. Genitourinary sites were defined as perineum (perianal area or buttocks), groin (inguinal region and thigh), lower abdomen (lower abdominal wall and back) and external genitalia (penis, scrotum, labia or introitus). The children were evaluated for comorbid conditions and risk factors including participation in sports, family members in health care, child abuse and genital shaving as a potential for increased risk.

The authors identified 37 boys and 23 girls. Sites for surgical abscesses included the perineum (43%), groin (28%), lower abdomen (20%) and external genitalia (8%). MRSA isolates occurred most commonly in the groin and genitalia comprising 36% of the infections. A single debridement of the wound was curative in 55 patients (92%). No deaths resulted from MRSA. No comorbid condition or specific risk factor was noted with the community acquired MRSA. MRSA was not identified in the abscess of any of the 40 patients before 2004 but after 2004 MRSA occurred in 8 of 20 patients (40%). This change was statistically significant. The incidence of MRSA continues to increase and was 75% (3 of 4 patients) in 2006 and 2007. Other offending pathogens include methicillin sensitive Staphylococcus aureus in 25 (42%), Escherichia coli in 6 (10%), Pseudomonas aeruginosa in 3 (5%) and Enterococcus in 3 (5%). All patients with community acquired MRSA were sensitive to trimethoprim-sulfamethoxazole and vancomycin, and resistant to azithromycin; 3 (38%) were resistant to fluoroquinolones; and 2 (25%) were resistant to clindamycin.

The authors report that MRSA has emerged as the most likely organism identified in a genitourinary soft tissue abscess within the pediatric population. When presented with a genitourinary abscess in a child, they recommend parenteral vancomycin if the child is hospitalized and oral trimethoprim-sulfamethoxazole if the child is going to be treated as an outpatient. When drainage is necessary, 1 incision is likely therapeutic. Sport activities did not appear to significantly increase the incidence of genital infections but when they did occur, MRSA was the offending isolate. MRSA infections may be associated with removal of pubic hair. The increasing prevalence of this grooming technique may place a number of teenagers at future risk.

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Genotype and Phenotype in Patients With Complete Androgen Insensitivity Syndrome 

Management of the gonads in cases of the complete androgen insensitivity syndrome (CAIS) has been perplexing. Cheikhelard et al (page 1496) from Paris, France performed a retrospective review and identified 29 patients with CAIS treated from early childhood to adulthood to assess the safety of maintaining gonads through puberty, particularly as relative to virilization during puberty and gonadal tumors. A secondary end point was to determine the need for vaginal surgery. The authors found that primary amenorrhea is no longer the most common mode of presentation for CAIS. Younger girls are diagnosed more often at prenatal evaluation or during repair of an inguinal hernia. Ultimately, the diagnosis of CAIS should rely on molecular biology. Gonadectomy previously had been recommended because of the high incidence of malignant potential and the possibility of virilization at puberty. All but 1 of the 29 patients had an androgen receptor mutation. Diagnosis was made prenatally in 5 cases, at familial screening in 3, at the time of a prepubertal inguinal hernia repair in 16 (13 were less than 1 year old) and at evaluation for primary amenorrhea in 5 (all born before 1988). All girls had completely normal female external genitalia. Clitoral hypertrophy and/or posterior fusion of the labia did not occur in any pubertal girl. Virilization did not occur in any of the 23 girls followed after puberty.

Prepubertal patients underwent gonadectomy only if they required repair of an inguinal hernia, in which case only 1 gonad was removed and the contralateral gonad was placed in the abdomen until the end of puberty at which time it was removed. Laparoscopic bilateral gonadectomy was performed in postpubertal girls with amenorrhea, and gonadectomy was ultimately performed in 25 girls (bilateral in 20). Vaginal dilation was performed following puberty because the vaginal vault was less than 4 cm in 12 girls. Only 1 girl required vaginal lengthening.

Interestingly derivatives of the wolffian duct were found microscopically in 31 of the 45 gonadal specimens (69%) and müllerian derivatives were found in 17 (38%). Sertoli adenomas and polar hamartomas were noted in the majority of specimens. Carcinoma in situ was found in only 1 girl 14 years old. The authors report that there was no correlation among the pattern of androgen receptor mutation, testis location, wolffian or müllerian derivatives and vaginal length. All 23 postpubertal girls had Tanner 5 breast development and all have been maintained on hormonal therapy. Of the 15 girls younger than 17 years 9 reported vaginal intercourse. The authors conclude that it is reasonable to preserve the gonads through puberty in girls with CAIS, since the risk of virilization is low and gonadal malignancy is rare. They also recommend delaying any vaginal reconstruction until after vaginal dilation has been attempted.

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Open Versus Laparoscopic Pediatric Pyeloplasty 

The Pediatric Health Information System (PHIS) contains inpatient data from a consortium of freestanding North American pediatric hospitals affiliated with Child Health Corporation of America. PHIS acquisition provides a large pool of data for in-depth assessment of a particular area of interest. Tanaka et al (page 1479) from Nashville, Tennessee used the PHIS data base to assist in the analysis of the benefits of laparoscopic versus open pyeloplasty in pediatric patients. They hypothesized that the potential benefits of laparoscopic surgery would decrease with patient age. A retrospective review of the PHIS data from January 2002 through June 2007 revealed the records of 5,695 children who had undergone correction of ureteropelvic junction obstruction. Exclusion criteria were patient age less than 1 month and greater than 19 years, and prior endopyelotomy. The final study population included 5,261 children from 39 hospitals. Laparoscopic and open approaches were compared based on age, sex, race, date of surgery, use of narcotics, length of stay and total adjusted charges. The age categories were defined as infant, preschool, grade school, preadolescent and adolescent. Cases were also encrypted for surgeons and hospitals to assess the effectiveness of surgical experience on outcome.

Overall, 324 (6.2%) procedures were performed laparoscopically. The number of laparoscopic procedures increased as expected across all age groups (range 38 of 2,579 in infants to 104 of 484 adolescents). Open and laparoscopic groups were well matched for age, sex and race. Physicians in the top quartile of laparoscopic procedures performed 7 or more laparoscopic pyeloplasties, which accounted for 70% of all laparoscopic procedures. Laparoscopic experience translated into shorter lengths of stay and number of pharmacy charges for narcotics. However, when open and laparoscopic pyeloplasty procedures in this top quartile were compared, the laparoscopic approach did not result in significantly shorter lengths of stay or fewer narcotic pharmacy charges in any age group. The authors conclude that laparoscopic benefits of shorter hospital stay and decreased narcotic usage are confined to children older than 10 years.

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Urinomas Associated With Posterior Urethral Valves 

Urinomas have been considered to serve as a pop-off mechanism protecting renal function when associated with a posterior urethral valve. Heikkila et al (page 1476) from Finland retrospectively assessed the presence of a urinoma in newborns with a posterior urethral valve to determine its clinical significance and the need for intervention. They reviewed records from 1953 to 2003 and identified 196 patients with a posterior urethral valve, including 17 (9%) with a urinoma. All urinomas were identified before age 9 weeks. These newborns were compared to a control group of 69 newborns younger than 9 weeks diagnosed with a posterior urethral valve but no urinoma. Of the cases 4 were identified before 1979 and 13 between 1980 and 2003 with the use of sonography. Posterior urethral valves were detected prenatally in 5 (29%) children with a urinoma and 22 controls (32%). The urinoma occurred in the perirenal space in 9 (53%) cases, 6 (35%) had urinary ascites and 2 (12%) had urinothorax. Bilateral hydronephrosis was noted in every patient with a urinoma. Vesicoureteral reflux and urinoma were present in 5 perirenal cases, 5 with urinary ascites and 1 with a urinothorax. Serum creatinine was similar in the children with a urinoma and the control group at presentation and at 6-month followup. Diethylenetetramine pentaacetic acid scintigraphy in 6 infants with a perirenal urinoma revealed a medium split function of 51% on the side of the urinoma. End stage renal disease at the age of 17 years occurred in 25% of patients with a urinoma and 23% of the control group.

The authors note that their data differ from that in the literature with a high association of reflux occurring not only with a perirenal urinoma but also with urinary ascites. They were unable to determine if a urinoma provided a protective or harmful effect. It is of interest that 13 infants with a urinoma underwent cutaneous ureterostomy. The authors admit that temporary ureteral diversion may not have been necessary in all cases. They conclude that the true incidence of a urinoma secondary to a posterior urethral valve is likely higher than previously reported and approaches 15%, which may be due to improved sonographic technology. Ultimately, management of the asymptomatic urinoma should be initially focused on treating the posterior urethral valve.