Latest Technologic and Surgical Developments in Using InterStim™ Therapy for Sacral Neuromodulation: Impact on Treatment Success and Safety

Abstract

Objectives

This article accompanies a “surgery in motion” DVD on sacral neuromodulation (SNM) with InterStim™ Therapy, which visualizes the implantation of the InterStim II system. The article describes the technical and surgical developments of SNM and their impact on treatment success, safety, and patient's quality of life (QoL).

Methods

Relevant literature on SNM with regard to technical changes and related clinical outcomes has been reviewed.

Results

Since its introduction in the early 1990s, SNM has proven useful in the treatment of several types of chronic urinary (and bowel) dysfunction. Recent technical improvements in devices and, in particular, the introduction of the tined lead 5 yr ago made SNM progress from an elaborate, open-surgery, general anesthesia, one-stage implant procedure to a minimally invasive, local anesthesia, percutaneous technique in two stages. The permanent tined lead implant enables a longer patient testing period (minimum of 14 d recommended) and less lead migration. This has considerably reduced technical failures and improved the success rate of the test phase; the response rate was almost doubled to approximately 80%. These improvements also affected tolerability, resulting in increased QoL for the patient. The use of the recently introduced smaller implantable neurostimulator InterStim II seems to further improve patient comfort and makes the implant procedure for the physician easier and shorter. However, this must be further addressed in clinical studies.

Conclusions

SNM with InterStim Therapy using the tined lead offers an efficient treatment modality for patients in whom conservative treatment has failed.

Introduction

Chronic voiding dysfunctions can considerably impair the patient's quality of life (QoL). These include overactive bladder (OAB), also referred to as the urgency-frequency syndrome, with or without urge urinary incontinence (UUI), and nonobstructive urinary retention (UR) [1], [2]. Diet modifications, behavioral therapy (ie, pelvic floor training, biofeedback), and medication belong to the standard conservative therapeutic options. If no symptomatic improvement is reached and/or the patient cannot tolerate the side effects of antimuscarinics, invasive surgical procedures, such as sphincteroplasty, augmentation cystoplasty, urinary diversion, among others, can be performed. However, potential disadvantages of these surgical therapies include limited efficacy, potentially severe complications, and irreversibility. These considerations underline the need for alternative therapies, such as electrostimulation, which has been used in urology for a long time. Direct stimulation and subsequent modulation of the sacral nerves has been proven effective and is today an established treatment option for patients refractory to or intolerant of conservative treatments.