Orchidopexy in children with Prader-Willi syndrome: Results of a long-term follow-up study.

INTRODUCTION: Prader-Willi syndrome (PWS) is a rare (1:20.000) genetic condition affecting both males and females. Among other features, in boys, the syndrome is characterized by cryptorchidism in 86-100% of cases, hypogonadism, delayed puberty and infertility. The aim of the present study is to appraise the results of orchidopexy in this selected population of children.

STUDY DESIGN: A follow-up study of children with PWS treated for undescended testes at a single institution over a 20-year period was performed. Patients were identified from a National PWS registry and reviewed at a special follow-up clinic. Data were collected from electronic and hard copies records and reported as median (range).

RESULTS: Thirty-three children (1-17 years) were identified. Co-morbidities were present in 22 (66%) and 15 (45%) were on growth-hormone therapy. Six patients (19%) had normal testes palpable in the scrotum; twenty-seven (81%) had undescended testes and required orchidopexy. Thirteen (48%) underwent a bilateral procedure for a total of 40 procedures. A 2-stage Fowler-Stephens orchidopexy was required in 2 (7%) testes. At surgery hypotrophic testes were documented in 6 (22%) patients. Age at orchidopexy was 1.4 years (0.5-5.5). Age at FU was 7.2 years (1.7-17). Length of follow-up is 3.5 years (0.4-14). At follow-up 16 (40%) testes were of normal size and palpable in the scrotum; 7 (17.5%) testes required redo-orchidopexy. All patients (6/33) over 16 years of age that had testosterone levels tested had values below normal limits after successful orchidopexy.

CONCLUSIONS: This study evaluates the results of orchidopexy in a large population of children with PWS. At follow-up, only 40% of testes were of normal size and in the scrotum. This information should be taken into consideration for patients' management and pre-operative parents' counseling.