Urinary stress incontinence, defined as the involuntary loss of urine from the urethra due to an increase in intra-abdominal pressure, is a common condition, affecting 6.5 million women in the United States. Conservative therapy usually includes pelvic floor muscle exercises. Biofeedback (See Policy No. 1998043), pelvic electrical stimulation (see policy No. 1998147), or periurethral bulking agents such as collagen (see policy No. 1997066) might also be tried. Various surgical options are considered when conservative therapy fails, including most prominently various different types of bladder suspension procedures, which intends to reduce bladder neck and urethra hypermobility by tautening the endopelvic fascia. For example, for colposuspension (i.e., the Burch procedure), sutures are placed in the endopelvic fascia and fixed to Cooper`s ligament or retropubic periosteum, which in turn creates a floor or hammock underneath the bladder neck and urethra. Recently, radiofrequency energy has been investigated as a technique to shrink and stabilize the endopelvic fascia, thus improving the support for the urethra and bladder neck. A radiofrequency device has been specifically designed for the treatment of urinary stress incontinence, which may be performed as an outpatient procedure under general anesthesia. The Renessa® procedure (Novasys Medical) induces collagen denaturation in the urethra with a specially designed 4-needle radiofrequency probe. Novasys Medical received clearance to market the Renessa® transurethral radiofrequency (RF) system through the U.S. Food and Drug Administration (FDA) 510(k) process in 2005. The device is indicated for the transurethral treatment of stress urinary incontinence due to hypermobility.
Published literature regarding transurethral radiofrequency tissue remodeling is inadequate to permit scientific conclusions regarding the safety and long-term efficacy of this procedure. Dmochowski and colleagues reported on a multi-institutional prospective case series of 120 consecutive women with urinary stress incontinence who underwent transvaginal radiofrequency bladder neck suspension (Dmochowski 2003). Enrolled patients had failed at least a 3-month trial of conservative therapy, including most commonly pelvic floor muscle exercises or pelvic floor stimulation. Follow-up examinations at 1, 3, 6, and 12 months consisted of a history, physical examination, and urodynamic studies. In addition, each patient completed a voiding diary and quality of life questionnaire. A cure was defined as a negative Valsalva maneuver; improvement was defined as decreased daily episodes of pad use. A total of 73% of patients were considered cured or improved at 12 months. More than 68% of patients reported satisfaction with the treatment. The authors conclude that the results are encouraging and that a 73% 12-month success rate suggests that this procedure has applicability for women with refractory incontinence who do not wish to undergo a more complicated surgical procedure. In 2002, Ross and colleagues conducted a multicenter, prospective single-arm study that included 94 women with stress incontinence. At 1 year, the objective cure rate was 79% based on a negative leak point pressure. Assessment of quality of life was also significantly improved. Larger controlled studies with longer follow-up are needed to further evaluate this procedure. As noted in a review of laparoscopic bladder neck suspension, initial promising results at 12 months declined to a 30% success rate at 45 months. (McDougall et al, 1999) These authors suggest that any new surgical technique for the treatment of stress incontinence should have more than 2 years of follow-up.
A retrospective follow-up of the transvaginal radiofrequency procedure was reported for 18 patients, 11 with genuine stress urinary incontinence and 7 with mixed incontinence. (Buchsbaum et al, 2006) At an unspecified time greater than 3 months following treatment, 6 of the 18 patients reported no urine loss and were satisfied with the outcome, 2 patients were lost to follow-up, and 10 reported continuing symptoms of incontinence. The relation between diagnosis (i.e., genuine stress-induced or mixed incontinence) and outcome was not presented.
Two publications were identified from a single company-sponsored randomized controlled trial of the transurethral radiofrequency procedure. (Appell et al, 2006) (Lenihan 2005). Quality of life measures did not differ between the radiofrequency group (110 subjects) and the sham-control group (63 subjects) at 12 months; however, a subgroup analysis showed benefit in patients with moderate to severe stress urinary incontinence. This study is limited by the post hoc subgroup analysis, loss to follow-up of nearly 20%, and lack of investigator blinding. Longer term follow-up, identification of the patient population that might benefit from this procedure, and independent replication is needed.
A 3-year follow-up from the industry-sponsored transurethral radiofrequency study described above was published (Appel et al, 2007). Of 110 treated patients, 26 (24%) were available for evaluation; control subjects were not contacted. Of the 26, five had obtained other treatments and were not included in the analysis (not counted as failures). An additional 3 patients were not included since they had no episodes of incontinence at baseline. The authors report that of the 18 (16%) included patients, 50% had reductions in incontinence episodes of greater than 50% (average of 3.5 daily incontinence episodes at baseline to 1.8 at 3 years after treatment). It should be noted that inclusion of all of the 26 subjects who had been contacted would result in a positive response rate of 38%. Interpretation of this study is limited due to the absence of the control group and inadequate numbers of treated patients in follow-up, along with excluding some patients from data analysis.
In 2009 results were published of a multicenter, 36-month, open-label, single-arm study of transurethral radiofrequency remodeling in 136 women with stress urinary incontinence caused by bladder outlet hypermobility who had failed non-surgical treatment and were not candidates for surgical therapy (Elser et al, 2009). Exclusion criteria included urge incontinence or stress urinary incontinence caused by intrinsic sphincter deficiency. By 12 months, 25 patients withdrew consent, 19 were lost to follow-up, and 17 reported lack of response, resulting in 75 patients (55%) who were evaluated at the 12-month follow-up. Efficacy, based on the percentage of patients with a 50% or greater reduction from baseline in daily incontinence episodes, was reported in 68 (50%) patients. Of the 75 evaluated at 12 months, 69% (38% of 136) reported at least a 50% reduction in leaked urine (median of 15 g) from baseline, and 45% (25% of 136) were dry. One patient reported increased leaking. No serious adverse events were reported. The most common adverse events at day 3 included dysuria (5%), urinary retention (4%), post-procedure pain (3%), and urinary tract infection (3%). This study is limited by the large loss to follow-up and the evidence is insufficient to alter the conclusions reached above.
The California Technology Assessment Forum (CTAF) completed a review of radiofrequency remodeling for the treatment of female stress urinary incontinence. The evidence for Renessa consisted of the single industry-sponsored randomized controlled trial (RCT) with 12-month follow-up (reviewed above) and 2 observational pilot studies that are discussed in this rationale (Appell et al, 2006) (Lenihan 2005). The Assessment concluded that although the benefits are clearly not as great as with the available gold standards (surgical approaches), the benefit-to-risk ratio is favorable for transurethral radiofrequency remodeling and does provide options for women with stress urinary incontinence, particularly for those who are not eligible for surgical intervention.
Eighteen-month follow-up data to the multicenter study (Elser, 2009) discussed above were published in 2010 (Elser, 2010). Sixty-three of 136 (46%) women who received treatment completed the 18-month follow-up and data were available on 60 women (44% of the study population). Thirty-one of the 60 evaluable women (61.7%) reported a reduction of at least 50% from baseline in leaks due to activity. In an intention-to-treat analysis of data from all 136 participants (last observation carried forward), 46.7% reported at least a 50% reduction in leaks from baseline. The 60 evaluable patients reported a median improvement of 9.5 stress leaks per week. The study is limited by a high drop-out rate and lack of a control or comparison group.