Infant's Age Influences the Accuracy of Rectal Suction Biopsies for Diagnosing of Hirschsprung's Disease.

ABSTRACT

BACKGROUND & AIMS: Hirschsprung's disease (HD) is a rare birth defect of the distal colon. Analysis of rectal suction biopsy (RSB) is considered to be the most reliable method for its diagnosis in infants. However, the diagnostic accuracy of RSB analysis could be affected by the patient's age, possibly because of rapid development of the enteric nervous system in the first weeks after birth. Because there is a trend toward testing for HD at early ages, we aimed to determine whether the diagnostic accuracy of RSB analysis is associated with the patient's age. METHODS: We performed a retrospective analysis of all patients from whom 1 or more RSBs were analyzed from 1975 through 2011 (529 RSBs from 441 patients). Outcomes of RSB analyses were categorized as positive, inconclusive, or negative for HD. Primary diagnoses, based only on RSB, were compared with final diagnoses made after at least 1 year of clinical follow-up. Age at time of RSB analysis was corrected for the gestational age. By using these criteria, we determined the diagnostic accuracy of RSB analysis for different age groups. RESULTS: RSB analysis identified HD in patients with sensitivity values of 46% (patients -45 to 7 days old), 47% (8-22 days old), and 62% (23-39 days old) (corrected for gestational age). The average sensitivity with which RSB analysis identified HD in patients older than 39 days was 88%. RSB identified HD in patients younger than 39 days old with significantly lower sensitivity than in older patients (50% vs 88%, P < .001). The specificity with which RSB identified infants without HD was not affected by age (average 95%). Of all RSBs, 11% were inconclusive for the diagnosis of HD. CONCLUSIONS: RSB analysis identifies HD in patients younger than 39 days old with only 50% sensitivity. Moreover, RSBs obtained from younger patients often lead to inconclusive outcomes and require additional biopsies. We propose that for infants suspected of HD at these ages, a noninvasive technique, such as anorectal manometry, should be used for a primary diagnosis. RSB should thereafter be used to confirm the diagnosis when the infant is older than 39 days.