Cryptorchidism is a relatively common condition, occurring in up to 9% in full-term infants and can occur in as many as 30% in premature neonates.[1] About 80% of undescended testes (UDT) migrate into the scrotum by 3 to 6 months of age.[2] UDT can be either unilateral or bilateral (10%).[3] Around 80% are palpable, and 90% of those are palpated in the inguinal canal. More than 90% of patients have a concomitant patent processus vaginalis.
Multiple risk factors contribute to the development of UDT. These include twinning, low birth weight, a birth weight that does not correlate appropriately with gestational age, and prematurity. Of these, prematurity is the most significant.
Types:
True undescended testis - The testis is located anywhere in the natural path of descent.
Ectopic undescended testis - testis is not anywhere along the natural path of descent.
Hypoplastic - underdeveloped testis
Dysgenetic - derangement of seminiferous tubules and function of testes
Vanished - thought to be due to intrauterine testicular torsion in late gestation.
Ascent - a testis that was in the scrotum but has since returned to the inguinal canal
Retractile - A testis that moves in and out of the scrotum
Acquired - failure of the spermatic cord to grow in proportion to body growth[4][5]
The testicle migrates from the abdominal cavity through the inguinal canal into the scrotum via the gubernaculum. Migration can become arrested at any point along its descent.
When viewing the internal ring of the inguinal canal during a laparoscopic approach, the vas deferens comes medially to join with the vasculature that comes in laterally. These then join to travel through the inguinal canal into the scrotum.[6]
Atrophic testis - if the testis is atrophic, perform an orchiectomy instead.
Technique:
A surgeon can perform an orchiopexy in several different manners. If the testis is not palpable, a laparoscopic approach is taken; this can be a one-stage or two-stage operation, depending on the laxity of the spermatic cord and testicular vasculature. If the testis is in the inguinal canal, an inguinal orchiopexy is performed. If the testis is retractile or at the top of the scrotum, a scrotal approach is the procedure of choice. Commonly, only one testis is fixated and then allowed to heal, so if blood supply is lost or infection develops, the patient has a remaining viable testis.[7][8][9]
Scrotal Approach
OR
Inguinal Approach - most common approach:
Laparoscopic Approach
If the testis cannot be mobilized sufficiently to pass through the inguinal canal into the scrotum without tension, a two-stage Fowler-Stephens approach is an option. There are several considerations when deciding between a one-stage and two-stage procedure; these include the distance from the testis to the internal ring (two-stage if > 2.5 cm), mobility of the vasculature (two-stage if excessive tension), and age of the patient (> 5 years old, consider two-stage).[10]
In the first step, the testis is identified laparoscopically; then, the vascular supply is ligated with minimal dissection of the spermatic cord. After several months, the patient undergoes a second laparoscopic surgery, the testis is identified, and viability assessed. If viable, the peritoneal attachments are taken down, providing sufficient length for the testis to sit in the scrotal pouch without tension.[8]
Along with the complications that accompany any procedure (i.e., infection, bleeding, scarring), there are several severe complications related directly to orchiopexy. These include:
Patients with UDT are at increased risk of infertility, testicular cancer in both testes, and testicular torsion. There is a 40 times increased risk of testicular cancer in the UDT, and the contralateral testis, even if located in the scrotum, has about a 20% increased cancer risk compared to the general population.[12]
Seminoma is the most common malignant tumor associated with undescended testicles. Orchiopexy should be performed after six months and before 18 months of age to reduce the risks of infertility and development of cancer.[13][14] Furthermore, patients with UDT are at increased risk of testicular torsion; this can also result in loss of the testis and increased risk of infertility.
Key points for multi-disciplinary care of pediatric patients with UDT:
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[2] | Berkowitz GS,Lapinski RH,Dolgin SE,Gazella JG,Bodian CA,Holzman IR, Prevalence and natural history of cryptorchidism. Pediatrics. 1993 Jul; [PubMed PMID: 8100060] |
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[9] | Rubenwolf P,Stein R, [Diagnosis and management of the undescended testis--an update in the light of the current guidelines]. Aktuelle Urologie. 2013 Nov; [PubMed PMID: 24258395] |
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[14] | Wang X,Chen Z,Qiu S,Cao D,Jin K,Li J,Chen B,Huang Y,Bao Y,Liu L,Wei Q, Evaluating the Effect of Cryptorchidism on Clinical Stage of Testicular Seminoma. Cancer management and research. 2020 [PubMed PMID: 32606976] |
[15] | Kim JK,Chua ME,Ming JM,Santos JD,Zani-Ruttenstock E,Marson A,Bayley M,Koyle MA, A critical review of recent clinical practice guidelines on management of cryptorchidism. Journal of pediatric surgery. 2018 Oct; [PubMed PMID: 29269095] |