InterStim and Motherhood

Study indicates device is safe for pregnant women and shows no major change after childbirth

Innovations Obstetrics & Gynecology - Fall 2018

 Sherif El-Nashar, MD, PhD

InterStim, a sacral neuromodulation device from Medtronic, has U.S. Food and Drug Administration (FDA) approval for three indications: overactive bladder and urinary leakage, fecal incontinence, and incomplete bladder emptying. University Hospitals Cleveland Medical Center physicians use InterStim to treat patients for all three of those indications and recently completed a clinical study that found the device is safe for use during pregnancy.

How Interstim Works

The InterStim procedure is completed in two separate outpatient procedures, says Sherif El-Nashar, MD, PhD, in the Division of Female Pelvic Medicine and Reconstructive Surgery, Department of Obstetrics and Gynecology, UH Cleveland Medical Center; Associate Professor of Obstetrics and Gynecology, Case Western Reserve University School of Medicine.

During the first procedure, physicians identify sacral nerve 3 (S3) and place a lead using x-ray fluoroscopy. In the operating room, physicians test the patient’s response to stimulation of that nerve. The patient is sent home with a small external device connected to a wire coming out through a very small skin incision. For two weeks, the patient carefully tracks symptoms. Physicians review that data to determine if the device is resulting in appropriate symptom improvement. If results are positive, patients then receive a permanent device that will need replacement through a short outpatient procedure when the battery runs out, approximately three to five years after placement.

InterStim is minimally disruptive to a patient’s life. The device is implanted through a small incision in the back, and the patient goes home the same day. People with sedentary jobs can return to work within a day or two, according to Dr. El-Nashar.

Patients can expect a significant reduction in symptoms, Dr. El-Nashar says. “InterStim is 80 to 85 percent successful in patients with refractory overactive bladder. These patients can be more active. They can play golf, go swimming and do all of the activities they like without worrying about leakage.”

Studying the Effects of Pregnancy

InterStim can be implanted in young children to treat specific syndromes. When females in this group of patients reach adulthood, a number may become pregnant. Dr. El-Nashar and several colleagues conducted a study¹ to determine whether the InterStim device affects pregnancy or vice versa.

“The result of the study indicated patients who had InterStim implanted as children or young adults to treat urinary and bowel issues do not require removal of the device during pregnancy,” Dr. El-Nashar says. “There are no safety concerns for the baby or mother. There is also no major change in how the device works after women deliver their babies.”

He adds that, while there is not a large pool of pregnant women with InterStim, clinicians at UH Cleveland Medical Center conduct research to provide the best available evidence to care for as many patients as possible, no matter how common or uncommon the circumstances.

Future Uses

Dr. El-Nashar considers InterStim the cutting-edge treatment for its three approved indications, but he wants to see expanded uses for the device. “The next step is to see if we can modify the use of InterStim to help other patients,” he says. “Could it be a good device to treat chronic pelvic pain? A non-narcotic treatment for chronic pelvic pain, which is difficult to treat, would be very important.”

A new generation of InterStim could be recharged without surgical intervention, according to Dr. El-Nashar. When that iteration of the device receives FDA approval, he wants to find out how it could be used to treat more medical conditions.

Contact Dr. El-Nashar at OBGYNInnovations@UHhospitals.org.

¹Mahran A, Soriano A, Safwat AS, Hijaz A, Mahajan ST, Trabuco EC, Siegel SW, El-Nashar SA. The effect of sacral neuromodulation on pregnancy: a systematic review. Int Urogynecol J. 2017 Sep;28(9):1357-1365.