Ipsilateral and contralateral patent processus vaginalis in pediatric patients with a unilateral nonpalpable testis

This study aimed to investigate the incidence of patent processus vaginalis (PPV) in pediatric patients with a unilateral nonpalpable testis and explore the associated factors. From May 2014 to April 2017, 152 boys who were diagnosed with a unilateral nonpalpable testis and underwent laparoscopy in Shanghai Children's Hospital (Shanghai, China) were included in this study. The data were collected and reviewed, and the results were analyzed regarding the age at operation, side, development, and position of the nonpalpable testis. The mean age of the patients was 2.6 (standard deviation: 2.3) years. The testis was absent in 14 cases, nonviable in 81 cases, and viable in 57 cases. The incidence of PPV was 37.5% (57 of 152) on the ipsilateral side and 16.4% (25 of 152) on the contralateral side. The ipsilateral PPV was more prevalent when the nonpalpable testis occurred on the right side ( P < 0.01). Besides, patients with a viable testis had a greater incidence of ipsilateral PPV than those with a nonviable or absent testis ( P < 0.01). Moreover, this rate was the highest when the testis was in the abdominal cavity and the lowest when the testis was in the scrotum (both P < 0.01). However, the incidence of contralateral PPV was independent of all the factors. In conclusion, in children with a nonpalpable testis, the incidence of an ipsilateral PPV was significantly related to the side, development, and position of the testis, while it was independent of these factors on the contralateral side.