Pediatric Andrology
Our Male Infertility Specialist:
Varicocele
The prevalence of varicocele in the pediatric population has been estimated to be 6% at age 10 years and 15% by age 13 years, which is similar to the prevalence among adult men. It is rarely diagnosed before puberty. About 95% of affected adolescent have left-sided varicocele, 2% have right sided and 3% have bilateral varicocele. Adolescent varicocele is not symptomatic and detected on routine physical examination. It is associated with decreased testicular volume and changes in the consistency of the testis. It is suggested that boys with testicular atrophy and size discrepancy of greater than 2 ml, a large unilateral varicocele, bilateral varicocele and abnormal gonadotropin-releasing hormone stimulation test undergo varicocele repair to prevent subsequent fertility problems. Recent advances in microsurgical technique improve the results of adolescent varicocelectomy. Inguinal approach with the preservation of testicular artery, advocated by Goldstein, is the procedure of choice. Microsurgical technique is similar to subinguinal procedure and result in preservation of artery, lumphatics and vas deferens. Subinguinal procedure is not recommended since testicular artery at this level is small. It may be performed by experienced microsurgeon in cases of previous inguinal surgery with abundunt scarring.
Successful varicocelectomy results in improvement of testicular growth which suggests the better fertility potential
Surgery for imperforate anus
Imperforate anus is part of a complex of congenital abnormalities, often directly involving the urinary tract, and sometimes associated with anomalies in the genital tract (e.g. cryptorchidism). Surgery for imperforate anus , especially the extensivce pelvic dissection for pull-through procedure and correction of recto-urethral fistula,could cause injuries to ejaculatory ducts , vas deferens and sympathetic fibers. As a result, obstruction of the vas deferens/ejaculatory duct and ejaculatory failure may occur. The prepubertal vas is very susceptible to any form of trauma, including simple manipulation, and any trauma to the vas in infancy can lead to fibrosis and atrophy. Another complication is severe and recurrent epididymitis. with subsequent epididymal obstruction In one series of 20 patients iatrogenic injuries were found in 50%, with coexisting congenital anomalies or postinfective epididymal obstruction in the rest.
Detailed examination is warranted since it may show surgically correctable blockage.A low volume azoospermic ejaculate without fructose and with low pH may indicate ejaculatory duct obstruction, correctable with transurethral resection of ejaculatory ducts.
Testicular biopsy commonly reveals normal spermatogenesis except undescended testes Vasography is performed to assess vasal patency. Epididymal obstruction may be corrected with ipsilateral or crossover vasoepididymostomy. Alternatively, sperm can be retrieved from the epididymis or testes and used for assisted reproduction with IVF/ICSI.
Cryptorchidism
Cryptorchidism ( undescended testis) is the absence of at least one testis in the scrotum. The incidence of cryptorchidism is age-dependent. At birth 1.8-4% of boys with normal birth weight are cryptorchid. At one year 0.8-1.1% of boys are cryptorchid .
The association of cryptorchidism and infertility is well established. The reported incidence of cryptorchidism among infertile men is 3.3- 8.3%.
The fertility potential of cryptorchid testis is low. Different theories have explained this phenmomenon based on
- Temperature factor: Spermatogenesis is exquisitely temperature sensitive. Both animal and human studies have shown that artificial elevation of testicular temperature results in impaired spermatogenesis.
- Central endocrine dysfunction: failure of testicular stimulation. Cryptorchidism may be considered as a form of hypogonadotropic hypogonadism. Newborn males with cryptorchidism do not exibit normal testosterone surge seen in newborn males with descended testis. Impaired LH and FSH response to GnRH has also been observed as well as impaired response of testicular testosterone to hCG.
These changes limit the transformation of gonocytes to Ad spermatogonia, cause atrophy and diminished number of Leydig cells and failure to develop primary spermatocytes. Despite total germ cell content in the first 6 monnths of life remains normal in most patients with cryptorchidism and lack of germ cells is generally very rare before 15 months of age, germ cells will be completely absent in 38% of cryptorchid testes of 2 year-old boys. From this time, the number of germ cells remains low not only in bilaterally and unilaterally undescended testes but also in contralateral testis ( in cases of unilateral cryptorchidism).Morphological studies of testicular biopsy specimens revealed progressive interstitial and tubular fibrosis between 2 years of age and puberty. No germ cells were found in 22% of 2 year old boys with unilateral cryptorchidism in the ipsilateral testis.
Cryptorchidism is associated with a high incidence of infertility even when unilateral. Despite prepubertal orchidopexy, adult patient have only 10% of the normal germ cell population.Patients with bilateral cryptorchidism demonstrate azoospermia or severe oligospermia.Sperm concentration after bilateral pediatric orchidopexy was at least 20x106 in only 21% of the adult men. Sperm concentration after unilateral orchidopexy was at least 20x106 in 69% of the patients. Infertility rates were reported as 32% in unilateral cryptorchidism and up to 60% in bilateral cryptorchidism. Lack of paternity involves 38% of married men with former bilateral cryptorchidism comapred with 10.9% of the unilateral cryptorchidism (Lee at al, 1997)
Although American Academy of Pediatrics recommends treatment for cryptorchidism at or near 1 year of age, there are still no reports of relationship between age of surgery and better fertility potential . This may be partly due to the fact that early orchidopexy was introduced to clinical practice quite recently and not to many of these patients reached adulthood.
Testicular biopsy is indicated in adult infertile men with the history of undescended testes. Normal spermatogenesis in the specimen may indicate iatrogenis obstruction of the vas deferens and/or epididymis, not uncommon after surgical treatment of undescended testis. In reconstructuble cases microsurgical reconstruction should be attempted. In most cases, assisted reproduction( testicular sperm extraction) is the treatment of choice.
Retractile testes( retraction of one or both testes toward the superficial inguinal pouch) in boys are usually not surgically repaired if the testes can be manually manipulated down into the scrotum either in the office or under anesthesia. It considered an innocuous form of undescended testes. However, the association between retractile testes, infertility and changes in germinal epithelium has been documented.Slight impairement in germ cell differentiation was reported in retractile testis during first 8 years of life ( Hadziselimivic, 1992). Significant alterations were found in semen analysis of young men treated for retractile testis at prepubertal age( after age 6). Oligospermia and asthenozoospermia were found in 76% and azoospermia in 13% of these patients. Early treatment of retractile testes may be considered to prevent fertility problems in the future.
Posterior urethral valves(PUV) are the most common cause of lower urinary tract obstruction in male infants. The treatment of this condition is surgical valve ablation.Fertility in patients with PUV may be impaired due to retrograde ejaculation secondary to abnormal posterior urethra and increased (up to 12%) incidence of undescended testes.Although paternity has been documented among patients with PUV, assisted reproduction may be used for some patients