Interstim Implant – Stage I

Anesthesia Implications

Position: Prone, arms tucked
Time: 30-60 min (short)
Blood Loss: Very Low (5-10 ml)
Post-op Pain: Moderate (3-6)
Maintenance Paralytic: Contraindicated
Lead: Yes

Approach – these procedures can be done under a MAC anesthetic, unless contraindicated. Some will opt to do a GETT in the event the patient is extremely obese and/or anxious.

muscle relaxants are contraindicated – The surgeon will be testing sacral nerves and muscle relaxants will interfere with this.

Tucked Arms (general considerations): Consider a second IV – once the procedure has started, it’s going to be VERY difficult to handle IV issues – especially if your only IV has problems. Ensure the IV is running and monitors are still functioning after tucking the patient’s arms

Prone Position (general considerations): Maintain cervical neutrality. Keep IV’s out of the antecubital space. The patients arms are typically flexed, which will kink the IV. Eye protection should be used as the prone position heightens the risk of corneal abrasion and/or traction on the globe (which can result in blindness). Check the patients eyes/ears/nose regularly throughout the case to ensure they are free of pressure. Positioning of the leads is typically high on the posterior and posterolateral back (somewhere free of pressure and out of surgical borders). Keep your connections and tubing where you’ll have fast access.

Fluoroscopy / Xray (general considerations): Have lead aprons and thyroid shields available. Alternatively, distancing yourself 3 to 6 feet will reduce scatter radiation to 0.1% to 0.025% respectively. Occupational maximum exposure to radiation should be limited to a maximum average of 20 Sv (joules per kilogram – otherwise known as the Sievert/Sv) per year over a 5 year period. Limits should never exceed 50 Sv in a single year.

In this procedure, leads will be surgically placed just under the skin in the upper lateral buttocks. These leads are designed to stimulate the S2 – S4 sacral nerves. Impulses to these nerve roots are designed to suppress the overactive nerves of the bladder.

The leads will be later attached to a device to test the efficacy of the stimulation. If the stimulation proves to be effective, the device will be permanently placed in stage 2.

Placement of the interstim device is designed to treat overactive bladder, incontinence, and non-obstructive urinary retention.

In some patients, a negative affect of the stimulation is loss of bladder control.