Supprelin LA (Histrelin) Subcutaneous Implant Procedure

Supprelin^® LA (histrelin acetate) is an implantable medication used to prevent further progression through puberty, for example in cases of precocious puberty or gender dysphoria.

The implant is inserted under the skin on the inside of the upper arm and slowly delivers medication into the tissues. The implant is typically left in place for a year. If pubertal suppression is needed for greater than a year, the implant is generally replaced. Sometimes the implant will be kept in place for a bit longer than a year. Your child’s endocrinologist will help determine if this medical treatment is appropriate for your child and the duration of treatment.

Placement of the implant requires a minimally invasive procedure which is completed by an attending pediatric surgeon. Children who are very young or easily get anxious may require sedation or, in rare cases, general anesthesia to undergo the procedure. Most children are able to complete the procedure in the outpatient surgery clinic with a local anesthetic and support from a child life specialist. Your child's care team will help determine the best approach.

Once your child’s clinical team determines a histrelin acetate implant is the right treatment for your child, they will help your family schedule the procedure.

Most children can have the implant placed as an outpatient appointment with the Division of Pediatric General, Thoracic and Fetal Surgery. This will be done at CHOP’s Philadelphia campus, and patients go home that same day.

Your child will arrive for the appointment about 45 minutes prior to the procedure time to have a numbing cream applied to the insertion site. A surgeon, nurse practitioner and child life specialist will meet with you to gather your child’s medical history, perform a physical exam and explain the procedure to both you and your child.

The child life specialist will work with your child on strategies like distraction and deep breathing exercises to calm them before and during the procedure. Parents and caregivers are encouraged to stay with their child throughout the appointment and procedure.

Immediately before the implant procedure, an additional numbing medication will be injected locally near the insertion site to prevent your child from feeling pain during the procedure.

The implant is just over an inch long. The surgeon will make a small (5mm) opening in the skin on the inner surface of your child’s upper arm, then use a special tool to insert the implant just beneath the skin. The implant is very narrow and about 1¼ inch long.

Some children may feel a gentle pressure as this occurs, while others will feel nothing. The small opening where the implant is placed will be closed with dissolvable sutures and surgical, waterproof glue. The procedure itself takes about 10 minutes, however, the entire appointment typically is about 60 to 90 minutes.

The implant will be placed on the inside of the upper arm. Children who require sedation for implant placement will require a longer appointment time – roughly a half day. This will allow extra time for your child to undergo sedation and recover from sedation after the procedure. The procedure itself will remain the same.

To prepare for sedation, your child may not eat any solid foods or drink anything other than clear liquids after 11 p.m. the night before the procedure. Children can continue to have clear liquids until their scheduled arrival time at the hospital. Learn more about pediatric sedation, medications and how to prepare, and be sure to follow the specific instructions provided by your child’s care team.

After your child’s histrelin acetate implantation, their incision will be closed with waterproof glue. You child will be able to shower any time after the procedure, but we recommend avoiding submerging the incision site in a bath or pool for 48 hours. The surgical glue is intended to stay intact and protect the incision site for 5 to 7 days and will fall off by itself.

Most children are able to attend school immediately after the procedure – either later the same day or the following day. We recommend avoiding contact sports and gym class for one week. After a week post-operatively, patients will have no sports or activity limitations due to the implant.

Complications from this procedure are uncommon. However, as with any incision, there is a small risk of infection. While minor discomfort or bruising at the incision can be expected, significant pain or bleeding is not.

Contact the Division of Pediatric General, Thoracic and Fetal Surgery at 215-590-2730 if your child develops:

• Significant pain or discomfort
• Drainage or bleeding at the incision site
• The incision becomes red, raised or is warm to the touch

Your child’s surgical team will work closely with the Division of Endocrinology and Diabetes to determine how long the histrelin acetate implant should remain in your child’s body and discuss when it should be removed.

Typically, the implant stays in place for 1 year and is then removed or replaced. Your child may require repeated implants over a period of years to delay puberty.

It is important for all patients who receive a histrelin acetate implant to follow up regularly with an endocrinologist who can assess the child and recommend when the implant should be removed or replaced. Even though the medication in the implant eventually runs out, the implant will still require surgical removal.

If you have questions about this procedure, contact the Department of Pediatric General, Thoracic and Fetal Surgery at 215-590-2730.

For questions about precocious puberty, gender dysphoria or guidelines for treatment decisions, contact the Division of Endocrinology and Diabetes at 215-590-3174.

CHOP’s Division of Pediatric General, Thoracic and Fetal Surgery has extensive experience using the histrelin acetate subcutaneous implants to treat pediatric patients with precocious puberty or gender dysmorphia.

Since 2008, we have completed more than 1,000 procedures, including insertions, replacements and removals. The vast majority of our patients have this procedure completed at our outpatient surgery clinic with a numbing medication, though anesthesia is available for children who are especially anxious.