The Clinical Utility of Testicular Prosthesis Placement in Children With Genital and Testicular Disorders

Stanley Kogan


Transl Androl Urol. 2014;3(4):391-397. 

In This Article

FDA Testis Prosthesis Announcement [1993]

The FDA today proposed that manufacturers of testicular implants be required to submit scientific data to show that these products are safe and effective.

Testicular implants, which are made of silicone, are intended for cosmetic purposes. They are commonly used to correct congenital abnormalities in infants and toddlers who are born without one or both testicles. They are also used in men who have had one or both testicles removed because of cancer or other diseases or who have lost one or both testicles due to injury. An estimated 1,000 are implanted yearly.

"We need to make sure these devices are safe and effective," said FDA Commissioner David A. Kessler, MD. "Therefore, we are proposing that companies submit data, just as we did for breast implants."

Testicular implants are pouches that are placed in the scrotum. They are made of solid or gel silicone and have a silicone covering. Some types are coated with polyurethane foam.

These implants were on the market prior to the Medical Device Amendments of 1976, which gave FDA regulatory authority over devices. Like other pre-amendment devices, testicular implants were allowed, under the law, to remain on the market with the understanding that FDA would later require manufacturers to demonstrate their safety and effectiveness.

Although some information on the risks and benefits of testicular implants is available, there is not enough scientific evidence to determine whether the benefits outweigh the risks.

The agency's safety concerns regarding the implants involve the lack of adequate information in these areas:

The incidence of leakage, hardening of surrounding tissue and rupture: the silicone gel in these implants may leak into adjacent tissue, causing problems similar to those seen with breast implants.

The long-term effectiveness of the implants: reported problems of unknown frequency and origin include infection, pain, discomfort, erosion of the device and its migration to other parts of the scrotum and abdomen. It is also not known how often these complications require corrective surgery.

The potential for long-term adverse effects, such as cancer, immune-related connective tissue disorders and reproductive problems: this type of information is particularly important because many of the implant users are young.

The immediate and long-term psychological benefits of the implants, such as patient satisfaction and improved self-image and psychological outlook.

If today's proposal is made final, manufacturers planning to continue marketing testicular implants will be required to submit a Premarket Approval Application demonstrating the safety and effectiveness of these products as a condition for keeping them on the market.

FDA's call for safety and effectiveness data on testicular implants is part of the agency's ongoing review of pre-1976 devices. In addition to requiring safety and effectiveness data on silicone gel breast implants, FDA recently proposed calling for safety and effectiveness data on saline breast implants and will soon do the same for inflatable penile implants, heart bypass blood pumps and cranial electro-therapy stimulators.

Today's proposal, which is being published in the Jan. 13 Federal Register, provides for a 60-day comment period. Comments may be submitted to Dockets Management Branch, HFA-305, Rm 1–23, 12420 Parklawn Dr., Rockville, Md. 20857.

FDA is one of the eight public health service agencies within the U.S. Department of Health and Human Services.

For the next several years testis implants were not manufactured and therefore were unavailable for implantation for pediatric and adult patients. Extensive clinical investigations were undertaken subsequently in order to meet the FDA's requests. The results of these studies eventually demonstrated their safety and absence of any statistical increase in diseases of concern, and both the FDA as well as the U.S. Institute of Medicine issued statements in this regard, allowing silicone prosthesis manufacture and implantation to resume.

During this time development of various additional prosthetic devices occurred. Compelled by the FDA to assess the safety and effectiveness of these devices, two sequential studies were undertaken, the first to assess a new silicone shell saline filled implant, and a subsequent to assess a silicone shell silicone gel filled ("elastomer") implant.[3] Review of the details of these studies indicate many unique and interesting aspects of the science and features of modern day testis implant devices:

Results of the Safety and Effectiveness of a New Saline-filled Testicular Prosthesis [1998–1999]

A 5-year multicenter, prospective clinical trial of a new saline filled silicone shell testis prostheses (Figure 1) was undertaken in 18 centers across the U.S., including both men and boys missing one or both testis. All patients had formal autoimmune and urologic evaluation before and after prosthesis placement. Adverse events and effectiveness were carefully assessed in all patients as well as additional outcome measures assessing quality of life with three validated psychological instruments.

Figure 1.

Saline-filled testis prosthesis showing self-sealing fill port (superior) and suture fixation tab (inferior).

Among 149 patients (76 pediatric) who completed the study, there was no evidence confirming any symptoms of autoimmune disease during the study. Major complications included device extrusion in three patients (2%) and device migration in one (0.7%). All extrusions occurred in pediatric patients having prosthesis placement through a scrotal incision. The reoperation rate was 2% for these issues. Minor complications reported were discomfort or pain (9% overall, but only 2% was deemed device-related pain), allergies or sinusitis (5%), scrotal swelling (3%) and hematoma, numbness, keloid and mild prosthesis migration. No patient was noted to develop a connective tissue disorder clinically or by questionnaire during a 1 year follow-up.

The scores on 2 of 3 validated, psychological quality of life instruments were stable or improved significantly (e.g., the Body Esteem Scale, and the Body Exposure in Sexual Activities Questionnaire) after the prosthesis was placed. Overall this study demonstrated significant increases in well being in the implant patients ("improved self-esteem, physical attractiveness and behavior and feelings during sexual activity"). Amongst the pediatric patients in particular, statistically significant evidence of improvement over baseline evaluations was seen in the Rosenberg Self-Esteem Scale.[3]

The study concluded that the saline filled, testis prosthesis was safe and well tolerated. In addition, the study showed that by validated self-esteem measures there is an improvement in quality of life in patients who receive such implants. Though there were previous reports alluding to these benefits, this was the first study done validating the quality of life benefits of testis implant surgery in a prospective studied manner. Because initial review of the study indicated superior results, the study was discontinued prematurely, though follow-up of these patients continued for an additional 5 years. These saline-filled prostheses remain available presently and are the only testicular prosthetic devices available in the U.S. at the present time (see below).

Results of the Safety and Effectiveness of a New Silicone Gel-filled (Elastomer) Testicular Prosthesis [2001]

In this multi-center prospective controlled study done at 10 investigating centers over a 1 year period, a new silicone gel-filled testis prosthesis (Figure 2) was evaluated to determine the safety and effectiveness of the device. Safety was assessed by collection of all adverse device placement related events, also comparing these with the data from the previous saline-filled prosthesis study. Efficacy was measured using the Patient Assessment Questionnaire, a previously validated quality of life instrument. Of the 55 patients assessed at 1 year (20 children), the adverse event rate was 2.7%. One patient was explanted because of scrotal infection and was successfully re-implanted without subsequent problem. Patient Assessment Instrument (PAI) satisfaction results for the subject's perception of their genitals scored a mean of 4.6±0.7 out of 5 (P<0.001). Ninety-three percent of patients agreed, or mostly agreed that "all in all I am glad I had the implant surgery"*.

Figure 2.

Soft-solid testis prostheses.

In my experience this prosthetic device was the most natural feeling prosthesis, also benefitting from the utility of its five different sizes. Unfortunately, after the study was completed the device was never produced because FDA requests for further manufacturing studies were deemed to be economically not feasible.

During these years an additional device was devised consisting of a semi-solid ovoid carved from a silicone block. These devices were described by the FDA as "silicone blocks which may be fashioned for the correction and treatment of esthetic defects", but were precluded from being labeled as a "testicular prosthesis". Currently in the U.S., these two devices are the only ones available and approved for cosmetic testicular replacement.