UNDESCENDED TESTIS

The undescended testis is a term we use to describe all instances in which the testis cannot be manually manipulated into the scrotum. The testes form from the medial portion of the urogenital ridge extending from the diaphragm into the pelvis. In arrested descent, they may be found from the kidneys to the internal inguinal ring. Rapid descent through the internal inguinal ring commences at approximately week 28, the left testis preceding the right. Adequate amounts of male hormones are necessary for descent. The highest levels of male hormones in the maternal circulation have been demonstrated at week 28. Thus, it appears that failure of descent may be related to inadequate male hormone levels or to failure of the end-organ to respond. The undescended testes may be found from the hilum of the kidney to the external inguinal ring. A patent processus vaginalis or true hernial sac will be present 90% of the time. The incidence is about 0.28% of the population, approximately 50% occurs on the right, 25% on the left, and 25% occur bilaterally. The diagnosis of undescended testes is usually made by the parents or first examining physician. The important point is the absolute necessity of distinguishing between retractile testes and the true undescended testes. Testes that can be drawn to the scrotum, even if they retract again, are retractile testes and not undescended, the squatting position may aid in helping descend the testes for exam. Retractile testis need no further surgical management.

Since Leydig cell degeneration can occur after age two, present recommendations are for orchiopexy before age 2. Although testicular malignancy is rare, undescended testes have a 40-50 times higher incidence of developing seminomas. This can occur in the contralateral normally descended testis as well as the undescended testis. Surgical repair does not reduce the incidence of malignancy, but does allow for examination and earlier detection. Another reason for surgical repair is the higher incidence of trauma and torsion in the undescended testis. Bilateral undescended testes may be initially treated with a four-week course of human chorionic gonadotrophin. Approximately 15-30% of patients will have descent with this therapy. Surgical repair is most commonly performed by a Dartos pouch technique. Laparoscopy helps in non-palpable undescended testis by identifying those testis that did not developed, suffered an ischemic intrauterine event, and in performing first stage Steven-Fowler technique.