The Prevalence of Bell Clapper Anomaly in the Solitary Testis in Cases of Prior Perinatal Torsion

PurposeBell clapper anomaly is associated with an increased risk of intravaginal testicular torsion. However, perinatal torsion is thought to be secondary to an extravaginal process. We quantified the contralateral prevalence of bell clapper anomaly in children found to have atrophic testicular nubbins secondary to presumed torsion during gestation to better define the subsequent risk of metachronous testicular torsion.Materials and MethodsInspection results for the presence of contralateral bell clapper anomaly was recorded by a single surgeon in 50 consecutive cases in which exploration for nonpalpable testes revealed a testicular nubbin. For comparison data were collected in 27 consecutive cases of acute testicular torsion. Anatomy of the normal contralateral testis was compared between the 2 groups.ResultsAverage age at surgery in the perinatal torsion group was 15 months vs 12.7 years in the acute torsion group. One case of partial contralateral bell clapper anomaly was discovered in the perinatal torsion group but no complete anomaly was found. In contrast, in older boys with acute testicular torsion complete bell clapper anomaly was found in 21 of the 27 contralateral testes (78%).ConclusionsIn older boys with acute testicular torsion contralateral bell clapper anomaly is highly prevalent, supporting the standard practice of contralateral testicular fixation in this clinical situation. However, the prevalence of contralateral bell clapper anomaly is exceedingly small in cases of monorchism after perinatal torsion, substantiating an insufficient risk of subsequent torsion to justify routine fixation of the solitary testis.