Interstim Therapy Can Prevent Urge Incontinence

Vol. 12 •Issue 17 • Page 17
Coding Outlook

Interstim Therapy Can Prevent Urge Incontinence

Interstim is a revolutionary new treatment for individuals suffering from the disorders of urge incontinence, urgency-frequency and urinary retention. This therapy is geared toward those patients who have failed the more conservative treatment such as medication, pelvic exercises and other more invasive surgeries.

Interstim Therapy, developed by Medtronic Inc., is a sacral nerve stimulation device that sends mild electrical pulses to the sacral nerves in the lower back that control the bladder, sphincter and pelvic floor muscles. The neurostimulator is placed under the skin of the abdomen and generates mild impulses via a thin wire.

The Interstim Process

The Interstim procedure is a two-stage process. First, the physician internally places electrodes in the patient’s lower back, using X-rays for precise placement. The electrodes are then tested to confirm perfect position before they are attached to an external device. The patient wears the test stimulator for approximately one week. This allows physicians to see if the procedure will work for the patient.

Insertion of simple and complex neurostimulator devices will continue to be reported by existing CPT codes. The choice of code is based upon the following:

•the anatomical site (i.e., cranial, spinal nerve, peripheral nerve);

•the surgical approach (i.e. open incision, percutaneous, subcutaneous)

•initial system placement or subsequent revision/ replacement of component (i.e., entire device, only pulse generator/transmitter, only electrode array)

The neurostimulator insertion/ removal codes do not differentiate between simple or complex components. Therefore, for insertion of either a simple or complex neurostimulator pulse generator see CPT 64590. For revision or removal of either a simple or complex neurostimulator pulse generator or receiver see CPT 64595. For the insertion of neurostimulator electrode see CPT 64561 (CPT Assistant Nov. 1999, Vol. 9).

Physicians perform periodic testing of the neurostimulator generator utilizing similar techniques as in the cardiac pacemaker check. The CPT code range for this testing of the neurostimulator is found using CPT 95970 thru CPT 95973.

If the patient’s symptoms have resolved when using the test electrical stimulator, the next step would be the insertion of the neurostimulator. The electrodes are attached to an implanted neurostimulator. A hand-held electromagnet device allows the patient or doctor to non-invasively control and adjust the strength of the stimulation, described by most people as a slight pulling sensation in the pelvic area; in the scrotum area for men and in the vagina for women (Emory Health Sciences Press Release, May 21, 2002).

The U.S. Food and Drug Administration (FDA) approved Interstim for use with urge incontinence patients in September 1997 and later for urgency-frequency and urinary retention patients in April 1999. Although it is not yet approved for the treatment of interstitial cystitis, pre-clinical trials are underway.

Side Effects/Precautions

Risks associated with this implant include infection and post-operative pain in the area of the implant. Adverse events related to the therapy, device or procedure can include: pain at the implant sites; infection or skin irritation; technical or device problems; transient electrical shock; adverse change in bowel or voiding function; numbness; nerve injury; seroma at the neurostimulator site; change in menstrual cycle; and undesirable stimulation or sensations.


Patients are contraindicated for implant of the Interstim Therapy System if they have not demonstrated an appropriate response to test stimulation or are unable to operate the neurostimulator. Also diathermy is contraindicated because diathermy’s energy can be transferred through the implanted system, which can cause tissue damage and result in sever injury or death.

Robyn Aubin is a senior consultant with the Coding and Audit Group with HP3.