The Use of Ultrasonographic Contralateral Testicular Volumetry as a Guide for Primary Inguinal Exploration for Unilateral Impalpable Undescended Testes

Introduction: Undescended testis (UDT) is a prevalent genital anomaly, with 12-24% of cases being impalpable. Since 1995, laparoscopy has been considered the gold standard for the treatment of impalpable UDT. However, a significant number of patients still require inguinal exploration after the visualization of testicular vessels and vas deferens when entering a closed ring.Objective: In this paper, we describe the use of contralateral compensatory testicular hypertrophy as a guide for surgical approach. We hypothesize that inguinal exploration is adequate for most patients with contralateral compensatory hypertrophy. Therefore, unnecessary laparoscopy can be avoided.Study design: The study was conducted at Ain-Shams University in the interval from March 2022 to January 2023. Inguinoscrotal ultrasonography (USS) was performed on all patients with unilateral impalpable UDT. Patients with contralateral testicular volume > 0.54 ml were included in the study and underwent primary inguinal exploration.Results: Among patients with unilateral impalpable UDT, 25 contralateral testes volumes matched our cutoff (0.54 ml), indicating the absence of the impalpable testis. These patients underwent primary inguinal exploration, revealing 21 testicular nubbins (84%), and four inguinal explorations were inconclusive (16%). The four inconclusive patients underwent laparoscopy, which confirmed a vanishing testes.Conclusion: Contralateral testicular compensatory hypertrophy serves as an indicator for primary inguinal exploration in unilateral impalpable UDT. We recommend conducting primary inguinal exploration in cases with a contralateral testicular volume > 0.54 ml.