Ultrasound findings to predict failure of conservative treatment in the appendix testis torsion

Background Torsion of the appendix testis (TAT) is considered the most common cause of acute scrotum in childhood. When clinical and ultrasound (US) findings agree with the diagnosis, after testicular torsion has been excluded, conservative therapy is attempted whereas scrotal exploration and removal of the hydatid are required when medical therapy has failed. We hypothesized there are US features that can predict the failure of conservative therapy. Methods We conducted a retrospective analysis on pediatric patients treated for TAT. The age of patients, number of days spent with symptoms before the start of treatment, presence of epididymitis and/or hydrocele, and dimension of the twisted hydatid were analyzed. A search for a correlation between these variables and failure of conservative treatment was conducted. Results Patients were divided into 2 groups based on the efficacy of conservative management: responders (group I) and non-responders subjected to surgical treatment (group II). No statistically significant differences were registered in regard to age (p = 0.25), average dimension of hydatid (p = 0.09), and time gap between symptoms and the start of therapy (p = 0.92) between the 2 groups. An associated epididymitis was described in 27.5% of patients in group I and 41.7% in group II (p = 0.03; OR 1.89), and associated hydrocele was described in 33.4% of patients in group I and 45.8% in group II (p = 0.03; OR 1.83). Considering the odds ratios, the probability of surgical intervention when presenting only epididymitis without hydrocele is estimated to be 15%, when presenting only hydrocele without epididymitis: 9%, with both epididymitis and hydrocele: 74%, and without epididymitis nor hydrocele: 2%. Conclusions The presence of both epididymitis and hydrocele at first US evaluation is associated with a high probability of conservative treatment failure, thus predicting the need for surgical intervention.