Surgical management of urinary incontinence

Computer simulations of thermal tissue remodeling during transvaginal and transurethral laser treatment of female stress urinary incontinence

BACKGROUND AND OBJECTIVES

A non-surgical method is being developed for treating female stress urinary incontinence by laser thermal remodeling of subsurface tissues with applied surface tissue cooling. Computer simulations of light transport, heat transfer, and thermal damage in tissue were performed, comparing transvaginal and transurethral approaches.

STUDY DESIGN/MATERIALS AND METHODS

Monte Carlo (MC) simulations provided spatial distributions of absorbed photons in the tissue layers (vaginal wall, endopelvic fascia, and urethral wall). Optical properties (n,μa ,μs ,g) were assigned to each tissue at λ = 1064 nm. A 5-mm-diameter laser beam and incident power of 5 W for 15 seconds was used, based on previous experiments. MC output was converted into absorbed energy, serving as input for finite element heat transfer simulations of tissue temperatures over time. Convective heat transfer was simulated with contact probe cooling temperature set at 0°C. Variables used for thermal simulations (κ,c,ρ) were assigned to each tissue layer. MATLAB code was used for Arrhenius integral thermal damage calculations. A temperature matrix was constructed from ANSYS output, and finite sum was incorporated to approximate Arrhenius integral calculations. Tissue damage properties (Ea ,A) were used to compute Arrhenius sums.

RESULTS

For the transvaginal approach, 37% of energy was absorbed in the endopelvic fascia target layer with 0.8% deposited beyond it. Peak temperature was 71°C, the treatment zone was 0.8-mm-diameter, and 2.4 mm of the 2.7-mm-thick vaginal wall was preserved. For transurethral approach, 18% energy was absorbed in endopelvic fascia with 0.3% deposited beyond the layer. Peak temperature was 80°C, treatment zone was 2.0-mm-diameter, and 0.6 mm of 2.4-mm-thick urethral wall was preserved.

CONCLUSIONS

Computer simulations suggest that transvaginal approach is more feasible than transurethral approach. Lasers Surg. Med. 49:198-205, 2017. © 2016 Wiley Periodicals, Inc.

Optical clearing of vaginal tissues, ex vivo, for minimally invasive laser treatment of female stress urinary incontinence

Near-infrared laser energy in conjunction with applied tissue cooling is being investigated for thermal remodeling of the endopelvic fascia during minimally invasive treatment of female stress urinary incontinence. Previous computer simulations of light transport, heat transfer, and tissue thermal damage have shown that a transvaginal approach is more feasible than a transurethral approach. However, results were suboptimal, and some undesirable thermal insult to the vaginal wall was still predicted. This study uses experiments and computer simulations to explore whether application of an optical clearing agent (OCA) can further improve optical penetration depth and completely preserve the vaginal wall during subsurface treatment of the endopelvic fascia. Several different mixtures of OCA’s were tested, and 100% glycerol was found to be the optimal agent. Optical transmission studies, optical coherence tomography, reflection spectroscopy, and computer simulations [including Monte Carlo (MC) light transport, heat transfer, and Arrhenius integral model of thermal damage] using glycerol were performed. The OCA produced a 61% increase in optical transmission through porcine vaginal wall at 37°C after 30 min. The MC model showed improved energy deposition in endopelvic fascia using glycerol. Without OCA, 62%, 37%, and 1% of energy was deposited in vaginal wall, endopelvic fascia, and urethral wall, respectively, compared with 50%, 49%, and 1% using OCA. Use of OCA also resulted in 0.5-mm increase in treatment depth, allowing potential thermal tissue remodeling at a depth of 3 mm with complete preservation of the vaginal wall.

Laser Treatment of Female Stress Urinary Incontinence: Optical, Thermal, and Tissue Damage Simulations

Treatment of female stress urinary incontinence (SUI) by laser thermal remodeling of subsurface tissues is studied. Light transport, heat transfer, and thermal damage simulations were performed for transvaginal and transurethral methods. Monte Carlo (MC) provided absorbed photon distributions in tissue layers (vaginal wall, endopelvic fascia, urethral wall). Optical properties (n,μ_a,μ_s,g) were assigned to each tissue at λ=1064 nm. A 5-mm-diameter laser beam and power of 5 W for 15 s was used, based on previous experiments. MC output was converted into absorbed energy, serving as input for ANSYS finite element heat transfer simulations of tissue temperatures over time. Convective heat transfer was simulated with contact cooling probe set at 0 °C. Thermal properties (κ,c,ρ) were assigned to each tissue layer. MATLAB code was used for Arrhenius integral thermal damage calculations. A temperature matrix was constructed from ANSYS output, and finite sum was incorporated to approximate Arrhenius integral calculations. Tissue damage properties (E_a,A) were used to compute Arrhenius sums. For the transvaginal approach, 37% of energy was absorbed in endopelvic fascia layer with 0.8% deposited beyond it. Peak temperature was 71°C, treatment zone was 0.8-mm-diameter, and almost all of 2.7-mm-thick vaginal wall was preserved. For transurethral approach, 18% energy was absorbed in endopelvic fascia with 0.3% deposited beyond it. Peak temperature was 80°C, treatment zone was 2.0-mm-diameter, and only 0.6 mm of 2.4-mm-thick urethral wall was preserved. A transvaginal approach is more feasible than transurethral approach for laser treatment of SUI.

Stress urinary incontinence in women: what options lie between traditional therapies and surgery?

Stress urinary incontinence affects women of all ages, becoming more prevalent with increasing age. While many nonsurgical therapies are available for the treatment of stress urinary incontinence, options are limited for women who fail to respond to these therapies yet may not be candidates for, or wish to avoid, surgery. This limitation prompted efforts to develop less-invasive procedures for treating stress urinary incontinence patients, including bulking-agent injections and a new transurethral, radiofrequency collagen-denaturation system. This new treatment (Renessa((R))) reduces tissue compliance without necrosis or stricture, thus differentiating it from a surgical radiofrequency treatment, transvaginal radiofrequency tissue ablation. The advent of new treatment options for stress urinary incontinence allows physicians to offer their patients a broader choice of treatment options, underscoring the importance of educating patients regarding all available therapies, including success rates and risk for complications. This is particularly important for women who have not responded to prior treatment strategies.

Treatment options for patients with suboptimal response to surgery for stress urinary incontinence

BACKGROUND

Many women with stress urinary incontinence (SUI) undergo surgery to relieve their symptoms. Currently, tension-free vaginal tape or transobturator tape sling procedures are the surgical treatments of choice. Although these procedures are often successful, a growing number of women experience suboptimal results ranging from improvement without cure to postoperative failure. Follow-up surgery often improves residual or recurrent symptoms but generally carries lower success rates and higher complication risks. Additionally, many women with suboptimal results are reluctant to undergo further surgery.

SCOPE

A PubMed literature search for studies of SUI treatment options published from 1986 to 2006 was performed.

FINDINGS

The literature revealed a gap in published studies addressing non-surgical options for patients with failed SUI surgeries. Studies of non-surgical treatments for SUI often exclude women who have had prior surgeries, or do not analyze this subgroup. It is, therefore, difficult to assess non-surgical treatment options for women with failed surgeries. Women whose residual or recurring SUI is attributable to intrinsic sphincter deficiency may instead elect the injection of a bulking agent. Bulking agents are associated with a low rate of complications but frequently require several injections to be successful. Women experiencing suboptimal surgical results whose SUI is attributable to hypermobility may select a new non-surgical treatment, radiofrequency collagen denaturation. This non-invasive procedure has also demonstrated a low rate of complications.

CONCLUSIONS

Considering the effect of SUI symptoms on women's quality of life, and with more women experiencing suboptimal results after surgery for SUI, it is important to assess alternatives to further surgery.

Injection therapy for stress urinary incontinence in adult women

Stress urinary incontinence (SUI) is prevalent in adult women and has a considerable impact on quality of life. However, it often remains undiagnosed and therefore untreated. Noninvasive treatment is likely to be offered in mild cases and may entail pelvic floor muscle re-education, minimally invasive devices or pharmacotherapy. Surgical intervention is widely considered as the only effective option for more severe SUI, although it is not suitable for all patients. Injection therapy with urethral bulking agents represents an alternative minimally invasive procedure and can be used for all types of SUI. Many bulking agents have been developed, although the ideal remains to be discovered. The safety and durability of agents remain a concern. No differences in agents from an efficacy point of view have been found. For many years urethral injection could only be administered endoscopically. The recent development of devices for blind injection has increased the speed and convenience of urethral injection, removing the need for surgical facilities. The subjective cure rate after injection therapy is higher than the objective one. A focus on the patient's wishes and expectations with respect to success and risks of a treatment for SUI is required. In addition, randomized clinical trials are mandatory to establish the place and efficacy of urethral bulking agents compared with conservative therapy (pelvic floor muscle re-education) in treating SUI in adult women.

Transvaginal radio frequency treatment of the endopelvic fascia: a prospective evaluation for the treatment of genuine stress urinary incontinence

PURPOSE

We evaluate the safety and efficacy of a new treatment modality for genuine stress urinary incontinence which was a transvaginal radio frequency applicator to deliver radio frequency energy to the endopelvic fascia. The purported mechanism of effect for this therapy is shrinkage of the collagenated tissue which composes the endopelvic fascia that supports the bladder neck and proximal urethra, thus stabilizing the proximal urethra and bladder neck. In prior animal trials and early pilot studies this therapy was shown to cause a reproducible thermal effect manifested by fascial shrinkage. Preliminary human trials indicated a therapeutic benefit of this therapy for women with genuine stress urinary incontinence.

MATERIALS AND METHODS

To our knowledge this is the first multicenter study of a transvaginal approach for radio frequency of the endopelvic fascia for treatment of genuine stress incontinence. Between June 1999 and June 2000, 120 consecutive women (mean age 49.9 years) at 10 sites underwent transvaginal radio frequency treatment in a prospective trial to evaluate the overall efficacy and safety profile of this therapy. All patients had preoperative urethral hypermobility (average cotton swab change 38 degrees). Detrusor instability was excluded by cystometry. In all procedures precisely controlled radio frequency energy was applied to the endopelvic fascia to heat and shrink the tissue. The patients were evaluated postoperatively at 1 week and at 1, 3, 6 and 12 months using objective and subjective measures. Primary end points consisted of physician assessment of continence, patient reported pad use and the number of patient reported episodes. Safety was determined for acute (immediate postoperative) and chronic time frames.

RESULTS

Of the 120 patients 96 completed 1-year evaluation. Average operative time was less than 30 minutes, and all patients were treated as outpatients. Preoperatively 101 patients (84%) averaged 1 or more episodes of urinary incontinence per day. At 3, 6 and 12 months 57%, 66% and 59% of patients, respectively, averaged 1 or no daily episodes of urinary incontinence. At 12-month followup 79 of 109 patients (73%) reported being continent or improved. Preoperatively, 43% of patients reported using 1 or no pads daily. At 3, 6 and 12 months 69%, 70% and 72% of patients, respectively, required 1 or no pads daily. On urodynamic evaluation at 12-month followup 76.0% of the patients did not leak with a Valsalva maneuver. A total of 30 cases were classified as failures and 11 women were lost to followup. There were no intraoperative complications, 3 (4%) minor postoperative complications which resolved, and no device related complications.

CONCLUSIONS

The transvaginal radio frequency applicator demonstrated good efficacy and excellent safety at 1-year followup. Ongoing analysis of the data has indicated opportunities for improvement of this new surgical technique that could result in higher efficacy rates without compromising safety. Further long-term evaluation is being conducted to assess chronic durability of the procedure.

Treatment of stress urinary incontinence: recent developments in the role of urethral injection

Stress urinary incontinence is prevalent in adult women and has a considerable impact on quality of life. However, it often remains undiagnosed and therefore untreated. Non-invasive treatment is likely to be offered in mild cases and may entail physiotherapy, minimally invasive devices or pharmacotherapy. Surgical intervention is widely considered as the only effective option for more severe cases. These strategies are not suitable for all patients, and urethral injection represents an alternative, minimally invasive procedure. The choice of the bulking agent is the key to the success of this treatment: the most extensively studied are silicone, polytetrafluoroethylene and bovine collagen. However, doubts regarding the safety and efficacy of these materials has led to the development of carbon-coated zirconium beads, calcium hydroxylapatite and dextranomer/hyaluronic acid (Dx/HA) copolymer. Of these, the most clinical experience has been gained with Dx/HA copolymer. Until 2 years ago, urethral injection could only be administered endoscopically. The recent development of devices for 'blind' injection has increased the speed and convenience of urethral injection, removing the need for surgical facilities. Although few data are yet available, it is conceivable that urethral injection administered 'blind' may in future be considered as an option for all patients failing non-invasive treatment.

Ball urethroplasty combined with Marshall-Marchetti-Krantz urethropexy versus suburethral sling in patients with intrinsic sphincter deficiency and urethral hypermobility

OBJECTIVE

It was our goal to compare the efficacy of a suburethral fascial sling with that of a combination of Marshall-Marchetti-Krantz urethropexy and Ball urethroplasty in patients with intrinsic sphincter deficiency and urethral hypermobility.

STUDY DESIGN

This study consisted of a retrospective observational evaluation of patients from 2 separate practice sites. Preoperative and postoperative data were collected from patients' medical records. The long-term results were based on a mailed questionnaire addressing bladder symptoms and quality-of-life issues.

RESULTS

Among a total of 48 patients, 37 (77. 1%) responded in the group undergoing Marshall-Marchetti-Krantz urethropexy combined with Ball urethroplasty, and 30 out of 35 (85.7%) patients replied in the suburethral fascial sling group. The mean length of follow-up was 2. 7 years (range, 1-5 years). The patients were similar in age, hormonal status, parity, and previous bladder neck surgery. Similar cure and improvement were demonstrated in both groups (86.6% in the suburethral fascia group and 89.2% in the group with the Marshall-Marchetti-Krantz procedure combined with Ball urethroplasty). No significant differences were found in urinary incontinence types, irritable bladder symptoms, voiding difficulties, or quality-of-life measures.

CONCLUSIONS

The suburethral fascial sling and a procedure consisting of Marshall-Marchetti-Krantz urethropexy combined with Ball urethroplasty have similar results in patients with intrinsic sphincter and urethral hypermobility.