Undescended testes in adults: Clinical significance of resistive index values of the testicular artery measured by Doppler ultrasound as a predictor of testicular histology

Purpose: We evaluated the clinical significance of arterial impedance as a predictor of testicular histology in adults with undescended (inguinal) testes. Materials and Methods: We performed arterial impedance and testicular diameter measurements with the use of color Doppler ultrasonography on 22 adults with undescended testes. Arterial impedance of the contralateral descended testes served as controls. All patients later underwent inguinal orchiectomy and the testes were examined histologically. Results: Of the 22 undescended testes, 7 had arterial impedance values below 0.50, and the other 15 had values equal to or above 0.50. All testes with arterial impedance values below 0.50 had histologic scores between 2 and 3, whereas the others had scores of 3 and 8. Arterial impedance values and testicular volumes in the contralateral testes were significantly higher than the undescended testes. Although some of the testes with arterial impedance values above 0.50 had histologic score 3, testes with arterial impedance values below 0.50 never exceeded score 3. Volume differences of the undescended testes were not statistically significant. Conclusions: Arterial impedance of an undescended testis may have a predictive value and provide more accurate information about its histology than the volume measurement itself.