Use of lumbar ultrasonography to detect occult spinal dysraphism

Various cutaneous stigmata and congenital anomalies are accepted as sufficient reasons to perform lumbar ultrasonography as a screening tool to rule out occult spinal dysraphism (OSD). The purpose of this study was to correlate presenting cutaneous findings with lumbar ultrasonography results based on a large number of lumbar ultrasonography tests obtained by regional primary care providers.

Over the course of 5 years, 1273 infants underwent lumbar ultrasonography screening at a major pediatric tertiary referral center. Of these infants, 1116 had adequate documentation for retrospective chart review. Referral sources included urban academic, urban private practice, and surrounding rural private practitioners. Presence of cutaneous stigmata and/or congenital anomalies and lumbar ultrasonography results were reviewed for all patients. When present, surgical findings were reviewed.

A total of 943 infants were referred for presumed cutaneous stigmata, the most common of which was a sacral dimple (638 patients [68%]) followed by hairy patch (96 patients [10%]). Other reported cutaneous findings included hemangioma, deviated gluteal fold, skin tag, and skin discoloration. In comparison, 173 patients presented with congenital anomalies, such as imperforate anus (56 patients [32%]) and tracheoesophageal fistula/esophageal atresia (37 patients [21%]), most of which were detected prenatally by fetal ultrasonography. A total of 17 infants underwent surgical exploration. Occult spinal dysraphism was diagnosed in 7 infants in the cutaneous stigmata group and in 10 infants in the group with congenital abnormalities. None of the cutaneous stigmata as recorded were found to be indicative of the presence of OSD.

Cutaneous markers as currently defined by general practitioners are not useful markers for predicting OSD. The vast majority of findings on lumbar ultrasonography studies performed under these circumstances will be negative.