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UNDESCENDED TESTES
Category: Pediatric Surgery
Abstract : Undescended testes : The testes descend into the scrotum in the 3rd trimester (passing through the inguinal canal at 24 - 28 weeks). Failure of testicular descent results in cryptorchidism (or undescended testes). Incidence 3% at birth (unilateral > bilateral). ~80% will spontaneously descend by 3 months. The incidence at 1 year is 1%. Classification - Retractile: an inte
Undescended testes :
The testes descend into the scrotum in the 3rd trimester (passing through the inguinal canal at 24 - 28 weeks). Failure of testicular descent results in cryptorchidism (or undescended testes).
Incidence
3% at birth (unilateral > bilateral). ~80% will spontaneously descend by 3 months. The incidence at 1 year is 1%.
Classification
- Retractile: an intermittent active cremasteric reflex causes the testis to retract up and out of the scrotum.
- Ectopic (<5%): abnormal testis migration below the external ring of the inguinal canal (to perineum, base of penis, or femoral areas).
- Incomplete descent (~95%): testis may be intra-abdominal, intra-inguinal, or pre-scrotal.
- Atrophic/absent
Risk factors
Pre-term infants; low birth weight; small for gestational age; twins.
Aetiology
Abnormal testis or gubernaculum (tissue which guides the testis into the scrotum during development); endocrine abnormalities (low level of androgens, human chorionic gonadotrophin (HCG), luteinizing hormone (LH), calcitonin gene-related peptide); decreased intra-abdominal pressure (prune-belly syndrome, gastroschisis).
Pathology
Degeneration of Sertoli cells; loss of Leydig cells; atrophy and abnormal spermatogenesis.
Long-term complications
- Relative risk of cancer is 40-fold higher in the undescended testis. Majority are seminomas; carcinoma in situ represents a small percentage (~2%). There is a slightly increased risk of cancer in the contralateral, normally descended testis.
- Reduced fertility.
- Increased risk of testicular torsion.
- Increased risk of direct inguinal hernias (due to a patent processus vaginalis).
Management
Full examination to elucidate if testis is palpable and to identify location. Assess for associated congenital defects. If neither testis is palpable, consider chromosome analysis (to exclude an androgenized female), and hormone testing (high LH and FSH with a low testosterone indicates anorchia).
Treatment should be performed within the first year. Hormone therapy (HCG, LHRH) stimulates testosterone production. Surgery consists of inguinal exploration, mobilization of spermatic cord, ligation of processus vaginalis, and securing the testis into a dartos pouch in the scrotal
wall (orchidopexy). Laparoscopy can be used in planning surgery and for treatment. Intra-abdominal testes may require division of spermatic vessels to provide extra length (relying on collateral blood flow from vas), 2-stage procedures, or microvascular autotransplantation.
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