Does the contralateral testicular volume decide the need for diagnostic laparoscopy in cases of unilateral impalpable undescended testis?

Abstract Background This study aimed the evaluation of the value of the calculated volume of a normal testis to predict the status of its contralateral impalpable side and hence decide the importance of laparoscopic exploration. Methods Patients with unilateral impalpable undescended testis – as confirmed by clinical and sonographic examination- were enrolled in our prospective interventional study between November 2018 and August 2022 at Elshatby University Hospital, Faculty of Medicine, Alexandria University. The volume and three-dimensional diameter of the normal contralateral testis were measured by the pre-operative US using the formula: Volume = L x W x H x π/6, where L is the length, W is the width, H is the height, and was correlated with the intra-operative laparoscopic findings. Results Seventy-six patients were included in our study. The age of the studied patients ranged between 6 months and 4 years with a mean of 2.17 ± 1.30 years; most of them were between one and three years old. Forty-six patients (60.5%) have left-sided impalpable testis and 30 patients (39.5%) have right-sided impalpable testis. The calculated volume of the contralateral normal testis was significantly larger in those patients who had both blind ending vas and vessels (0.89 ± 0.16) and in those who had an atrophic testis passing through the deep inguinal ring (DIR) –which was excised through the inguinal region- (0.83 ± 0.20) than in those patients who had their testes intra-abdominal (0.53 ± 0.18) or passing through the DIR to the inguinal region (0.80 ± 0.19). (Kruskal Wallis test; p < 0.001*). Conclusions The calculated sonographic volume of a normal testis can predict the status of its contralateral impalpable side significantly with sensitivity & specificity of 75.0% & 88.89% respectively and a cut-off point of ≤ 0.674; hence, helps in parent counselling preoperatively. Trial registration Name of the registry: Clinicaltrials.gov PRS. Trial registration number: NCT05933811. Date of registration: 10-7-2023 (retrospectively registered). URL of trial registry record: https://clinicaltrials.gov.