# Cryptorchidism: Diagnosis and Orchiopexy

## Definition and Epidemiology

Cryptorchidism refers to the failure of one or both testes to descend into the scrotal position. It occurs in approximately 3% of full-term male infants at birth, with a significantly higher incidence—up to 30%—in premature infants. Spontaneous descent of the testis occurs in about 75% of full-term cryptorchid boys by six months of age. After this period, spontaneous descent becomes rare, and the prevalence of cryptorchidism at one year of age is roughly 1%. The condition is unilateral in 80-90% of cases and bilateral in 10-20%, with the right side being more commonly affected than the left.

## Embryology of Testicular Descent

Testicular descent occurs in two distinct phases during fetal development. The first, the transabdominal phase, takes place between weeks 10 and 15 of gestation. During this phase, the gubernaculum shortens under the influence of insulin-like factor 3 (INSL3) and Mullerian inhibiting substance (MIS), moving the testis from its retroperitoneal position to the internal inguinal ring. The second phase, the inguinoscrotal phase, occurs between weeks 28 and 35 and is mediated by testosterone and calcitonin gene-related peptide (CGRP). This phase guides the testis through the inguinal canal into the scrotum, with the processus vaginalis serving as a pathway. Arrest of descent at any point during these phases results in cryptorchidism.

## Classification

### By Location

Cryptorchid testes are classified based on their anatomical location. Abdominal testes lie above the internal inguinal ring and are typically non-palpable. Canalicular testes are located within the inguinal canal. Ectopic testes deviate from the normal descent path and may be found in locations such as the superficial inguinal pouch, perineum, femoral region, or even contralateral to the expected side. Gliding testes can be brought to the upper scrotum but retract immediately.

### Important Distinctions

It is crucial to differentiate true cryptorchidism from retractile testis. A retractile testis descends into the scrotum but retracts due to an active cremasteric reflex; it can be manually placed into the dependent scrotum and will remain there temporarily. Retractile testes do not require surgical intervention but should be monitored for the ascending testis phenomenon, where the testis migrates cephalad over time and may eventually require orchiopexy. Non-palpable testes may be intra-abdominal, atrophic (vanished testis), or absent (monorchism).

<image>Diagram showing normal testicular descent pathway and locations of cryptorchid testes including abdominal, canalicular, and ectopic positions</image>

## Clinical Evaluation

### Physical Examination

Physical examination should be conducted in a warm room with warm hands to minimize cremasteric reflex activity, and the child should be relaxed, ideally positioned in a frog-leg or cross-legged posture. A systematic palpation approach includes milking the inguinal canal from the anterior superior iliac spine (ASIS) toward the scrotum, palpating the superficial inguinal pouch, and assessing the scrotum. A bimanual exam can be performed by blocking the inguinal canal with one hand while sweeping the testis toward the scrotum with the other. The examiner should determine whether the testis is palpable or non-palpable, identify the exact location of palpability, assess whether the testis can be brought into the scrotum and if it remains there, and evaluate the contralateral testis for compensatory hypertrophy (greater than 2 cm), which suggests absence of the contralateral testis. Examination should also include assessment for an associated inguinal hernia, which is present in approximately 90% of cryptorchid testes.

### Imaging

Imaging is not recommended for palpable undescended testes because physical examination alone is sufficient for surgical planning. For non-palpable testes, ultrasound has a sensitivity of only about 45% for detecting intra-abdominal testes and is therefore not recommended as the primary diagnostic tool. Magnetic resonance imaging (MRI) offers better sensitivity but remains limited and is not routinely recommended. Computed tomography (CT) is discouraged due to radiation exposure risks in children. Diagnostic laparoscopy remains the gold standard for evaluating non-palpable testes.

### Hormonal Evaluation

Hormonal evaluation is unnecessary for unilateral palpable cryptorchidism. It is indicated in cases of bilateral non-palpable testes to differentiate between anorchia, intra-abdominal testes, and disorders of sexual development (DSD). In patients with bilateral cryptorchidism accompanied by hypospadias, a mandatory DSD workup is required. Hormonal tests include the human chorionic gonadotropin (hCG) stimulation test, where a rise in testosterone confirms the presence of testicular tissue. Anti-Mullerian hormone (AMH) and inhibin B serve as additional markers of testicular tissue. Karyotyping is performed if DSD is suspected, and follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels are elevated in cases of anorchia.

## Consequences of Cryptorchidism

### Infertility

Germ cell degeneration in undescended testes begins as early as one to two years of age. Bilateral cryptorchidism is associated with an infertility rate of 30-60% despite orchiopexy, whereas unilateral cryptorchidism has a near-normal fertility rate if orchiopexy is performed early. Even the contralateral normally descended testis may exhibit subtle histologic abnormalities. Early orchiopexy, ideally before 12 to 18 months of age, improves fertility outcomes by minimizing germ cell damage.

### Malignancy

Cryptorchidism increases the relative risk of testicular cancer by four to eight times compared to the general population. This risk persists even after orchiopexy, which does not eliminate the risk but facilitates surveillance. The highest malignancy risk is associated with intra-abdominal testes. Seminoma is the most common tumor type arising in undescended testes, while non-seminomatous tumors are more common in the normally descended contralateral testis. Orchiopexy performed before puberty may reduce, but not eliminate, malignancy risk. For post-pubertal diagnoses, orchiectomy is often considered instead of orchiopexy, especially for intra-abdominal testes, due to the high malignancy risk and impaired spermatogenesis.

### Other Risks

Additional risks associated with cryptorchidism include an increased likelihood of testicular torsion due to abnormal fixation and a high incidence of inguinal hernia resulting from a patent processus vaginalis in 90% of cases. Psychological impacts related to the condition should also be considered.

<image>Histologic comparison of testicular biopsies from a normally descended testis and an undescended testis showing germ cell degeneration and reduced spermatogonia count</image>

## Management

### Timing of Surgery

The American Urological Association (AUA) guideline recommends orchiopexy between six and twelve months of age or within six months of diagnosis if the presentation is later. This timing aims to minimize germ cell damage and optimize fertility potential. Waiting beyond twelve months offers no benefit since spontaneous descent after six months is extremely rare. Hormonal therapy using hCG or GnRH to induce descent is not recommended by the AUA due to low success rates (approximately 20%) and a high rate of re-ascent.

### Orchiopexy for Palpable Testis

#### Standard Inguinal Orchiopexy

The standard inguinal orchiopexy is the most common surgical procedure for palpable undescended testes. The operation begins with an inguinal incision and opening of the external oblique fascia. The spermatic cord structures are identified and isolated, and the processus vaginalis, which is patent in 90% of cases, is ligated. The spermatic cord is mobilized by dividing cremasteric fibers and lysing adhesions to gain sufficient length to bring the testis into the scrotum without tension. A subdartos pouch is created within the scrotum, and the testis is delivered into this pouch and secured with absorbable sutures. The success rate of this procedure exceeds 95%.

#### Prescrotal (Bianchi) Approach

The prescrotal or Bianchi approach uses a single scrotal or high-scrotal incision and is suitable for low inguinal or high scrotal testes. This technique involves less dissection, offers better cosmetic results, and is simpler than the inguinal approach. However, it is not appropriate for high inguinal or abdominal testes.

### Management of Non-Palpable Testis

#### Diagnostic Laparoscopy (First Step)

Diagnostic laparoscopy is the gold standard for evaluating non-palpable testes. If the testis is found at or near the internal ring, a one-stage laparoscopic or open orchiopexy is performed. For intra-abdominal testes with adequate vascular length, either a one-stage or staged Fowler-Stephens orchiopexy is appropriate. If laparoscopy reveals blind-ending vas deferens and vessels, this indicates a vanished or regressed testis, and no further surgery is required beyond confirming the absence of a testicular nubbin. When vas and vessels enter the inguinal canal, inguinal exploration is necessary to locate the testis or remnant.

#### One-Stage Laparoscopic Orchiopexy

This procedure is suitable for intra-abdominal testes located close to the internal ring with sufficient vessel length. The testis, vessels, and vas deferens are mobilized laparoscopically and brought into the scrotum either through the inguinal canal or a newly created medial port site.

#### Fowler-Stephens Orchiopexy (Staged)

For high intra-abdominal testes with short spermatic vessels, the Fowler-Stephens orchiopexy is performed in two stages. The first stage involves laparoscopic clipping and division of the spermatic vessels, relying on collateral blood supply from the artery to the vas deferens and the cremasteric artery to maintain testicular viability. Six months later, the second stage mobilizes the testis on the vasal pedicle and brings it into the scrotum. This staged approach has a testicular viability success rate of 80-90%, although there is a 10-20% risk of testicular atrophy due to vascular compromise.

| Scenario | Procedure | Success Rate | Key Details |
|---|---|---|---|
| Palpable, inguinal/canalicular | Standard inguinal orchiopexy | >95% | Ligate processus vaginalis; subdartos pouch |
| Palpable, low inguinal/high scrotal | Prescrotal (Bianchi) approach | >95% | Single scrotal incision; less dissection |
| Non-palpable, near internal ring | One-stage laparoscopic orchiopexy | >90% | Adequate vessel length required |
| Non-palpable, high abdominal (short vessels) | Staged Fowler-Stephens | 80-90% viability | Stage 1: clip vessels; Stage 2 at 6 months |
| Non-palpable, blind-ending vessels at laparoscopy | No further surgery needed | N/A | Confirms vanishing testis |
| Post-pubertal, intra-abdominal | Orchiectomy (often preferred) | N/A | High malignancy risk; impaired spermatogenesis |

#### Single-Stage Fowler-Stephens

In selected cases with adequate collateral circulation, a single-stage Fowler-Stephens orchiopexy can be performed, combining vessel division and orchiopexy in one procedure. This approach has a slightly lower success rate compared to the staged method.

<image>Laparoscopic views during evaluation and Fowler-Stephens orchiopexy showing intra-abdominal testis, vessel clipping at stage 1, and mobilization on vasal pedicle at stage 2</image>

### Post-Pubertal Undescended Testis

Orchiopexy is still recommended for viable testes in post-pubertal patients who desire preservation. However, for intra-abdominal testes discovered after puberty, orchiectomy is often reasonable due to the high malignancy risk, impaired spermatogenesis, and the fact that orchiopexy does not reverse existing damage. Patients should be counseled regarding lifelong self-examination and cancer surveillance.

## Retractile Testis Management

No surgical intervention is necessary if the testis reaches the dependent scrotum and remains there temporarily. Annual follow-up until puberty is advised. If the testis becomes ascending—meaning it no longer reaches the scrotum—orchiopexy is indicated, as ascending testis occurs in approximately 30% of cases.

## Postoperative Care

Orchiopexy is typically performed as an outpatient procedure. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used for pain management. Activity restriction, particularly avoiding straddle activities, is recommended for two to four weeks. Follow-up visits are scheduled at two to four weeks postoperatively and again at six months to assess testicular position, size, and viability. Long-term care includes educating the patient on self-testicular examination at puberty and counseling regarding the risk of testicular cancer.

## Clinical Pearls

Imaging studies are not recommended for palpable undescended testes because physical examination alone suffices for surgical planning. Orchiopexy should be completed by twelve months of age according to AUA guidelines, as earlier surgery preserves more germ cells and optimizes fertility. Diagnostic laparoscopy is the gold standard for evaluating non-palpable testes, given the low sensitivity of ultrasound for intra-abdominal testes. The presence of blind-ending vessels at the internal ring during laparoscopy confirms a vanishing testis, obviating the need for further exploration. Hormonal therapy with hCG is not recommended due to low and transient success rates. While orchiopexy does not eliminate the risk of testicular cancer, it facilitates examination and surveillance; patients should be counseled on lifelong self-examination. Finally, bilateral non-palpable testes with or without hypospadias require a thorough evaluation for disorders of sexual development, including karyotyping and hormonal studies, before any surgical intervention.

## References
- AUA Guideline on Evaluation and Treatment of Cryptorchidism, 2014 (revised 2018)  
- EAU/ESPU Guidelines on Pediatric Urology (Cryptorchidism), 2024 Update  
- Kolon TF, et al. "Evaluation and treatment of cryptorchidism: AUA guideline." *J Urol*. 2014;192(2):337-345.  
- Hadziselimovic F, et al. "Infertility in cryptorchidism is linked to germ cell apoptosis." *Horm Res*. 2007.  
- Tasian GE, et al. "Diagnostic performance of ultrasound in non-palpable cryptorchidism." *Pediatrics*. 2011.  
- Campbell-Walsh-Wein Urology, 12th Edition, Chapter on Cryptorchidism