Renal ultrasound abnormalities in children with syndromic and non-syndromic microtia

Renal abnormalities are commonly considered in the work up of pediatric patients with external ear malformations. However, there is little consensus regarding an appropriate renal screening protocol for patients with microtia. We sought to characterize renal abnormalities detected on ultrasonography in pediatric patients with microtia.

We conducted a retrospective cohort study of pediatric patients diagnosed with microtia who underwent renal ultrasound from 1991 to 2014 at a single tertiary academic institution. Renal ultrasound reports and medical records were reviewed to assess for renal abnormalities and to determine whether patients required specialist follow-up or interventions. Audiograms and otolaryngology notes were used to determine patterns of hearing loss. The following additional information was recorded from the electronic medical records: patient sex, microtia grade (I-IV), microtia laterality, and known associated syndromes. Characteristics were compared between those who did and did not have renal ultrasound findings using Fisher's exact test. Univariate logistic regression analysis was performed to determine factors associated with renal ultrasound findings.

The majority of patients in this cohort were syndromic (n = 51, 64%) with grade III microtia (n = 46, 58%) and conductive hearing loss (n = 58, 72%). Syndromic children with microtia demonstrated a higher crude rate of renal ultrasound abnormalities (22%) than children with isolated microtia (7%). Of these patients, 69% required specialist follow-up. Univariate logistic regression analysis did not identify predictors that were significantly associated with renal ultrasound findings.

Fairly high rates of abnormalities in syndromic and non-syndromic patients may warrant screening renal ultrasound in all patients with microtia, especially given the high percentage of findings requiring renal follow-up. A prospective study to formally evaluate screening efficacy is needed.