Association between the risk of testicular torsion among acute scrotum and ambient temperature

Abstract

(Objectives) Testicular torsion (TT) is a socially and clinically important urological emergency condition because delayed diagnosis and treatment can lead to testicular loss. Although a possible association between TT and low ambient temperature has been argued, the clinical significance of the association has not been fully elucidated. We retrospectively collected acute scrotum cases and investigated the association between the risk of TT among acute scro-tums and ambient temperatures on the day of onset. (Patients and methods) We studied 105 consecutive acute scrotum patients with suspected TT who underwent urgent surgical exploration between October 2004 and October 2014. The patients' age, residential area, time and date of onset, laboratory findings, and operative findings were collected from their medical records. Climate data, including daily mean ambient temperature (DMAT), diurnal temperature change (DTC), humidity, and atmospheric pressure at the time of onset, were obtained from the Japan Meteorological Agency website. The chi-square and Wilcoxon rank sum tests were used to evaluate statistical differences. Logistic regression analysis used to identify significant predictors of TT. (Results) The median age of the patients was 13 years (range, 1-43 years). The affected side was the right/left/bilateral side in 46/58/1 of the patients. Surgical exploration revealed TT in 67 patients. The remaining 38 non-TT patients included 12 with testicular appendage torsions, 12 with epididymal appendage torsions, 9 with epididymitis, 2 with orchitis, 2 with idiopathic hematomas, and 1 with allergic purpura. The median DMATs at the day of onset were 10.8°C (1.8-29.4°C) in the TT patients and 19.4°C (1.9-29.1°C) in the non-TT patients. The incidence of TT among the patients with acute scrotum explored surgically (TT incidence) in days with DMATs < 15°C (80%) was significantly higher than that in days with DMATs > 15°C (45%; p<0.001). During days with DMATs >15°C, the TT incidence in days with DTCs >10°C (62%) was significantly higher than that in days with DTCs < 10°C (32%; p=0.037). Multivariate analysis revealed higher age (14), low serum C-reactive protein level (<0.5 ng/ml) and low DMAT (< 15°C) were significant risk factor for TT in patients with acute scrotum undergoing surgery. (Conclusions) It should be noted that in this study, the onset of acute scrotum during days with low ambient temperatures or large DTCs was associated with a moderate to high possibility of TT.