Gadolinium-infusion magnetic resonance angiogram: a new, noninvasive, and accurate method of preoperative localization of impalpable undescended testes

The undescended testis: Clinical management and scientific advances

Undescended testes (UDT), where one or both testes fail to migrate to the base of the scrotum, can be congenital (2-5% of newborn males) or acquired (1-2% of males). The testis may be found in any position along its usual line of descent. Cryptorchidism affects the developing testicular germ cells and increases the risk of infertility and malignancy. Clinical management aims to preserve spermatogenesis and prevent the increased risk of seminoma. Examination to document the testicular position will guide the need for imaging, medical management and the surgical approach to orchidopexy.

Magnetic resonance imaging for locating nonpalpable undescended testicles: a meta-analysis

BACKGROUND AND OBJECTIVE

Preoperative imaging techniques may guide management of nonpalpable, cryptorchid testicles. We evaluated conventional MRI for identifying and locating nonpalpable testicles in prepubescent boys via meta-analysis.

METHODS

Databases including Medline were searched from 1980 to February 2012. Eligible studies included ≥10 boys with cryptorchidism/suspected cryptorchidism and reported data on testicular presence/absence and position (abdominal, inguinal, or scrotal) as determined by imaging and surgery. Two investigators independently reviewed studies against inclusion criteria. We captured the number of testicles that were correctly and incorrectly identified and located, relative to surgically verified status, and estimated sensitivity and specificity by using a random-effects model.

RESULTS

Eight unique prospective case series included 171 boys with 193 nonpalpable testicles (22 with bilateral testicles). Surgery identified 158 testicles (81.9%) present and 35 absent. MRI correctly identified testicles with an estimated median sensitivity of 0.62 (95% Bayesian credible interval [BCI]: 0.47-0.77) and a specificity of 1.0 (95% BCI: 0.99-1.0). MRI located intraabdominal testicles with a sensitivity of 0.55 (95% BCI: 0.09-1.0) and inguino-scrotal testicles with a sensitivity of 0.86 (95% BCI: 0.67-1.0). We were not able to obtain estimates for MRI sensitivity or specificity for locating atrophied testicles. The estimated specificity for location-specific testicles reached almost 100%.

CONCLUSIONS

Conventional MRI has low sensitivity for estimating the population sensitivity for identifying the presence of nonpalpable cryptorchid testicles. When testicles are identified, MRI is poor at locating both atrophied and intraabdominal testicles but performs modestly well in locating those in the inguino-scrotal regions.

MAGNETIC RESONANCE ANGIOGRAPHY FOR THE NONPALPABLE TESTIS: A COST AND CANCER RISK ANALYSIS

PURPOSE

For the unilateral nonpalpable testis standard management is open surgical or laparoscopic exploration. An ideal imaging technique would reliably identify testicular nubbins and safely allow children to forgo surgical exploration without compromising future health or fertility. Our goal was to perform a cost and risk analysis of magnetic resonance angiography (MRA) for unilateral nonpalpable cryptorchid testes.

MATERIALS AND METHODS

A search of the English medical literature revealed 3 studies addressing the usefulness of MRA for the nonpalpable testicle. We performed a meta-analysis and applied the results to a hypothetical set of patients using historical testicular localization data. Analysis was then performed using 3 different management protocols-MRA with removal of testicular nubbin tissue, MRA with observation of testicular nubbin tissue and diagnostic laparoscopy. A cancer risk and cost analysis was then performed.

RESULTS

MRA with observation of testicular nubbin tissue results in 29% of patients avoiding surgery without any increased cost of care. Among the 29% of boys with testicular nubbins left in situ and observed the highest estimated risk was 1 in 300 of cancer developing, and 1 in 5,300 of dying of cancer.

CONCLUSIONS

A protocol using MRA with observation of inguinal nubbins results in nearly a third of boys avoiding surgical intervention at a similar cost to standard care without any significant increased risk of development of testis cancer.

Lost and found testes: the importance of the hCG stimulation test and other testicular markers to confirm a surgical declaration of anorchia

BACKGROUND

In patients with impalpable testes,laparoscopy or open surgery is considered conclusive in establishing the absence of testicular tissue.

METHODS

Retrospective chart review.

RESULTS

Over a 22-year period, 4 out of 82 patients with a diagnosis of bilateral anorchia by laparoscopy or laparotomy had persistent testicular tissue suggested by endocrine evaluations. The clue to the presence of testicular tissue was: (1) a pubertal rise in plasma testosterone (2 patients); (2) the presence of possible Müllerian structures and of a detectable plasma anti-Müllerian hormone (1 patient), and (3) the fact that one of the gonads had not been seen at surgery (1 patient who still had a testosterone response to hCG postoperatively). Testes were localized by venography (3 patients) and laparotomy (1 patient).

CONCLUSION

A surgical diagnosis of bilateral anorchia needs to be confirmed by hCG stimulation, gonadotropin levels, or other markers of testicular function.

Using gadolinium-infusion MR venography to show the impalpable testis in pediatric patients

OBJECTIVE; This study evaluated the adjunctive value of gadolinium-infusion MR venography to locate the impalpable testis.

SUBJECTS AND METHODS

Routine MR imaging and MR venography were performed in 34 patients presenting with impalpable testis. MR venography was performed by dynamic injection of gadopentetate dimeglumine bismethylamide with images taken at delayed venous phases. The site of the testis was determined by detection of the contrast-enhanced pampiniform venous plexus.

RESULTS

A total of 44 impalpable testes were examined. Twenty-six hypoplastic canalicular testes, two testes at pelvic skinfold, four atrophic testes in the scrotum, and five intraabdominal testes were detected on both routine MR imaging and MR venography. Five "vanishing" testes in the scrotum and two at the groin region were detected by MR venography but not on MR imaging.

CONCLUSION

Gadolinium-infusion MR venography is superior to MR imaging in the detection of atrophic testes. The method is a useful adjunct in patients with negative MR imaging findings.

Is human chorionic gonadotropin useful for identifying and treating nonpalpable testis?

PURPOSE

We evaluated the efficacy of human chorionic gonadotropin (HCG) for identifying and treating nonpalpable testis. We then compared the cost-effectiveness of this approach to that of laparoscopy.

MATERIALS AND METHODS

We reviewed patient charts during a 15-month period and identified 51 boys (64 testes) who underwent surgery to correct cryptorchidism. There were nonpalpable testes in 17 cases and bilateral cryptorchidism in 2 for a total of 19 impalpable testes. All patients were offered a full course of HCG. Those electing hormonal treatment received intramuscular injection of 2,000 IU/m.2 HCG (maximum 1,500 IU/injection) 3 times weekly for 3 weeks.

RESULTS

A full course of HCG was given in 8 patients (10 testes). Of the 10 testes 8 became palpable after HCG treatment, including 1 atrophic nubbin located in the inguinal canal. Of the 2 testes that remained impalpable 1 discovered at the level of the renal vessels had complete epididymal nonunion and 1 was located closer to the inguinal ring. All 9 untreated patients underwent laparoscopy, which identified 3 intra-abdominal, 3 vanished and 2 peeping testes, and 1 atrophic testis in the inguinal canal.

CONCLUSIONS

HCG therapy is valuable for identifying and treating nonpalpable testis. Using this agent enabled the testicle to be detected while avoiding the risks and cost associated with the laparoscopic procedure.

A new management algorithm for impalpable undescended testis with gadolinium enhanced magnetic resonance angiography

PURPOSE

We evaluated the diagnostic accuracy of preoperative localization of impalpable undescended testis using ultrasound and gadolinium (Gd) enhanced magnetic resonance angiography (MRA).

MATERIALS AND METHODS

Ultrasound and Gd-MRA were performed prospectively in 21 boys (23 impalpable testes) with cryptorchidism before laparoscopy and surgical exploration. Gd-MRA was done using a 1.5 Tesla magnetic resonance scanner with a turbo field echo technique after bolus intravenous injection of 0.4 mmol./kg. body weight of Gd diethylenetriaminepentaacetic acid. A total of 10 dynamic scans were acquired during 15 minutes after Gd injection to cover the early arterial and delayed venous phases. All patients subsequently underwent diagnostic laparoscopy and definitive surgery.

RESULTS

Ultrasound correctly localized 9 of 10 intracanalicular testes but failed to reveal any intra-abdominal or vanishing testes. In contrast, Gd-MRA correctly localized 4 intra-abdominal, all 10 intracanalicular and 8 canalicular vanishing testes. In 1 patient with an intra-abdominal vanishing testis ultrasound and Gd-MRA failed to make the diagnosis. When correlated with the findings of subsequent laparoscopy and surgical exploration, Gd-MRA had a diagnostic sensitivity of 96% and a specificity of 100% for localizing impalpable undescended testes. Based on Gd-MRA and ultrasound findings laparoscopy could have been avoided in 18 of 23 cases (78%). No adverse effect was associated with Gd use in this study.

CONCLUSIONS

Gd-MRA accurately diagnoses vanishing testes and reliably differentiates intraabdominal from intracanalicular impalpable testes, allowing definite preoperative planning of the surgical approach and avoiding unnecessary laparoscopy. A new management algorithm for impalpable testis in patients with cryptorchidism is proposed based on ultrasound and Gd-MRA findings.

A new management algorithm for impalpable undescended testis with gadolinium enhanced magnetic resonance angiography

PURPOSE

We evaluated the diagnostic accuracy of preoperative localization of impalpable undescended testis using ultrasound and gadolinium (Gd) enhanced magnetic resonance angiography (MRA).

MATERIALS AND METHODS

Ultrasound and Gd-MRA were performed prospectively in 21 boys (23 impalpable testes) with cryptorchidism before laparoscopy and surgical exploration. Gd-MRA was done using a 1.5 Tesla magnetic resonance scanner with a turbo field echo technique after bolus intravenous injection of 0.4 mmol./kg. body weight of Gd diethylenetriaminepentaacetic acid. A total of 10 dynamic scans were acquired during 15 minutes after Gd injection to cover the early arterial and delayed venous phases. All patients subsequently underwent diagnostic laparoscopy and definitive surgery.

RESULTS

Ultrasound correctly localized 9 of 10 intracanalicular testes but failed to reveal any intra-abdominal or vanishing testes. In contrast, Gd-MRA correctly localized 4 intra-abdominal, all 10 intracanalicular and 8 canalicular vanishing testes. In 1 patient with an intra-abdominal vanishing testis ultrasound and Gd-MRA failed to make the diagnosis. When correlated with the findings of subsequent laparoscopy and surgical exploration, Gd-MRA had a diagnostic sensitivity of 96% and a specificity of 100% for localizing impalpable undescended testes. Based on Gd-MRA and ultrasound findings laparoscopy could have been avoided in 18 of 23 cases (78%). No adverse effect was associated with Gd use in this study.

CONCLUSIONS

Gd-MRA accurately diagnoses vanishing testes and reliably differentiates intraabdominal from intracanalicular impalpable testes, allowing definite preoperative planning of the surgical approach and avoiding unnecessary laparoscopy. A new management algorithm for impalpable testis in patients with cryptorchidism is proposed based on ultrasound and Gd-MRA findings.