Original Research

Transobturator Sling Compared With Single-Incision Mini-Sling for the Treatment of Stress Urinary Incontinence A Randomized Controlled Trial Lucyana M. Djehdian, MD, Maita P. Araujo, MD, PhD, Claudia C. Takano, MD, PhD, Carlos A. Del-Roy, MD, PhD, Marair G. F. Sartori, MD, PhD, Manoel J. B. C. Girão, MD, PhD, and Rodrigo A. Castro, MD, PhD OBJECTIVE: To determine the efficacy and safety of a single-incision mini-sling compared with a transobturator midurethral sling for stress urinary incontinence (SUI) treatment. METHODS: This prospective single-center randomized controlled trial involved 130 women with a diagnosis of SUI. Primary outcomes were the objective and subjective cure rates, defined as negative cough stress and pad tests, and satisfaction rates. Quality of life assessed by the Incontinence Quality of Life Questionnaire and the Urogenital Distress Inventory Short Form, operation time, complications, and reoperation rates were also recorded. The efficacy was analyzed using a noninferiority test with a margin of 15%. For the noninferiority test, a P value ..05 rejects the noninferiority hypothesis of the mini-sling. RESULTS: Sixty-four patients in the mini-sling group and 56 in the transobturator group completed the 12-month follow-up. The objective cure rates for the mini-sling and the transobturator sling were 68.1% and 81.9% (absolute difference 13.8; 90% confidence interval [CI] 1.5–26.1; P5.439) and the subjective cure rates were 81.1% and 88.5% (absolute difference 7.4%; 90% CI 2.8–17.6; P5.110), respectively. There was a significant improvement in quality of life in both groups. Thigh pain was

From the Section of Urogynecology and Pelvic Surgery, Department of Gynecology, Federal University of São Paulo, São Paulo, Brazil. Corresponding author: Lucyana M. Djehdian, MD, Avenida Alberto Ramos, 50, Apartment 63, Bl 2, São Paulo, SP, Brazil 03222-000; e-mail: lucyana6[email protected] yahoo.com. Financial Disclosure The authors did not report any potential conflicts of interest. © 2014 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins. ISSN: 0029-7844/14

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greater after the transobturator sling, four patients (7.1%) compared with zero (P5.045). The mean operation time was 5 minutes shorter for the mini-sling procedure (P5.000). Five patients (7.8%) in the mini-sling group and one patient (1.8%) in the transobturator group underwent surgical reintervention for persistent SUI (P5.213). CONCLUSION: The noninferiority of the mini-sling could not be demonstrated in this study at the 12-month follow-up. The mini-sling was associated with shorter operative time and less postoperative thigh pain. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT01094353. (Obstet Gynecol 2014;123:553–61) DOI: 10.1097/AOG.0000000000000148

LEVEL OF EVIDENCE: I

S

tress urinary incontinence (SUI) is defined as “the complaint of involuntary leakage of urine on effort or exertion, or on sneezing or coughing.”1 The surgical treatment of SUI remains the major type of management for this condition. Sling techniques, typically using synthetic material, exhibit good results with low associated morbidity.2 Midurethral slings inserted by a retropubic or transobturator approach have become the gold standard surgical treatment for women with SUI.3,4 Although they present high cure rates, there are some important complications inherent to the passage of the needle through the retropubic space or obturator foramen as vascular or visceral injuries and thigh pain. Alternatively, mini-slings were developed and introduced as an attempt to avoid such adverse events. The Ophira mini-sling procedure is a minimally invasive approach to midurethral sling placement. This

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sling device can be placed through a small vaginal incision under local anesthesia. A potential advantage is its shorter insertion trajectory with transobturator or retropubic approaches not being required. With that, the mini-sling method intends to result in a shorter operation time and fewer complications. The primary objective of this study was to compare the efficacy between a mini-sling and a transobturator midurethral sling in the surgical treatment of SUI in women. The secondary objective of this study was to evaluate the effect of SUI surgery on quality of life and to detect possible complications and reoperation rates of the mini-sling and transobturator midurethral tape surgeries. We hypothesized that the single-incision mini-sling procedure is not inferior to the transobturator midurethral sling for SUI treatment.

MATERIALS AND METHODS This study is a clinical, prospective, single-center, randomized controlled trial conducted at the Federal University of São Paulo, a tertiary referral academic center in São Paulo, Brazil, between August 2008 and December 2011. The research protocol was reviewed and approved by the Institutional and National Ethics Committee, registered in ClinicalTrials.gov (NCT01094353), and all included patients provided written informed consent. Funding was provided by Federal University of São Paulo. This is not an industry-sponsored trial. Promedon had no role in the design or analysis of this study and only donated the devices for scientific and academic purposes. The inclusion criteria were women older than 18 years of age with SUI confirmed by all: a positive cough stress test, the presence of urine leakage greater than 2 g measured by a standardized pad test with 250-mL bladder volume, and urodynamic stress incontinence. The exclusion criteria were the presence of concomitant pelvic organ prolapse greater than stage I,1 detrusor overactivity, a postvoid residual volume more than 100 mL, coagulation disorders, current urinary tract infection, sequela of previous radiation therapy to the pelvis, anticoagulant therapy, acute vulvovaginitis, and anesthesia contraindications. The participants were randomly allocated to a single-incision mini-sling or a transobturator midurethral tape by a simple randomization procedure using a random number generator computer program. Randomization was performed at the moment of inclusion by a nurse blinded to women’s histories. Group assignment was concealed in consecutively numbered, sealed, opaque envelopes that were opened in the operating

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room just before the procedure. The preoperative evaluation consisted of a general anamnesis and a detailed urogynecologic interview, physical examination, an urodynamic study, and a 20-minute padweighing test.5,6 After emptying the patient’s bladder with a catheter, the 20-minute pad test was performed with a 250-mL saline solution bladder volume. Each patient returned to a standing position with a preweighed perineal pad placed inside the underwear. The patients were asked to perform each activity 10 times: cough, bear down, perform deep knee bends, jump up and down in place, and walk up and down five stairs. Also, they were asked to wash their hands under cold water for 1 minute, walk in the hall for 10 minutes, and then return for pad removal. The pad was then weighed, and the net weight was calculated by subtracting the original dry weight to achieve a measure of the total urine lost during the 20-minute exercise. A positive pad weight result was defined as more than 2 g leakage. The terminology, methods of assessment, definitions, classifications, and units used in this study followed the standards jointly recommended by the International Continence Society and the International Urogynecological Association except where specifically noted.1 All the study participants also completed the Incontinence Quality of Life Questionnaire validated for the Portuguese language.7 This questionnaire is divided into three subscales: avoidance and limiting behavior, psychosocial affect, and social embarrassment. A score of 100 represented the best possible quality of life, and zero represented the worst possible quality of life. The Urogenital Distress Inventory Short Form is a validated six-item questionnaire that assesses lower urinary tract symptoms. Patients were asked to indicate if they experienced a symptom and the degree to which the symptom bothered them. Scores vary from 0 (not at all) to 18 (greatly).8 Symptoms of urgency were determined by patient’s self-report and by patient’s response “slightly,” “moderately,” or “greatly” to the Urogenital Distress Inventory Short Form questions 1 and 2. The Ophira mini-sling is a synthetic monofilament polypropylene suburethral tape (Fig. 1). It is a small sling consisting of a central tape that measures 3839 mm and two self-anchoring “fishbone” columns sized 32 mm each (a total of 102 mm of synthetic material). This mini-sling procedure was performed under local anesthesia using 2% lidocaine by a vaginal approach with a single vaginal incision. The minisling was anchored to the obturator internus muscle at the level of the arcus tendineus according to

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Fig. 1. The mini-sling and its retractable insertion guide. Image courtesy of Promedon. Used with permission. Djehdian. Single-Incision Mini-Sling for SUI Treatment. Obstet Gynecol 2014.

Palma’s described technique.9 The tape was adjusted by a cough stress test with 250–300 mL of intravesical volume to prevent urinary leakage and to avoid overtension. Cystoscopy was not routinely performed, and no Foley catheter was left in place. Two grams of cephalosporin and 500 mg metronidazole were administered intravenously for infection prevention. Fourteen patients in whom perineorrhaphy was associated received spinal anesthesia. The transobturator sling is a synthetic tape consisting of two connectors made of polydimethylsiloxane and a polypropylene central tape that measures 282 mm (Fig. 2). Surgery was performed under regional anesthesia using a transobturator approach in an “outside-in” fashion according to Delorme’s described technique.10 A urinary catheter was inserted before the sling placement and was removed on the day after surgery. Intraoperative cystoscopy was performed only if any tissue injury was suspected. The

Fig. 2. The transobturator tape and the helical needles. Image courtesy of Promedon. Used with permission. Djehdian. Single-Incision Mini-Sling for SUI Treatment. Obstet Gynecol 2014.

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procedures were performed by five surgeons (L.M.D., C.C.T., C.A.D.-R., M.G.F.S., R.A.C.) who had extensive experience in transobturator surgery and had performed at least five mini-sling procedures before the study. All surgeons performed both procedures. The intraoperative and perioperative data included the operating time, the level of pain, and the complications. Patients in both groups had their postvoid residual volumes measured by vesical catheterization after two spontaneous micturitions before discharge from the hospital. In cases of a postvoid residual greater than 100 mL, patients were discharged with a urethral catheter and were reevaluated after 7 days. As a precaution, all patients from the study were only discharged 24 hours after surgery as advised by the local ethics committee. Postoperative pain was evaluated using a visual analog scale. Patients were requested to assign a number ranging from 0 (no pain) to 10 (worst pain experienced) on postoperative day 1 to avoid any residual anesthetic effect and again 1 week after surgery. Thigh pain was characterized by persistent pain after 4–6 weeks. De novo urgency was defined as the postoperative development of symptoms of urgency, which were not present before surgery and persisted for more than 1 month. These symptoms were based on patient’s self-report of urgency and patient’s response to the Urogenital Distress Inventory Short Form questions 1 and 2. Urinary tract infections were considered related to the surgical procedure if developed up to 30 days postoperatively. The diagnosis of urinary tract infection was made with symptoms associated with leukocyturia in urinalysis. The complications are described according to International Urogynecological Association and International Continence Society terminology and classification, where relevant.11 Follow-up visits were scheduled for 7 days and 1, 3, 6, and 12 months after the procedure. The postoperative evaluation consisted of a history and physical examination. The quality-of-life questionnaires were given again, and any complications were evaluated. At the 12-month evaluation, a cough stress test with a 250-mL bladder volume and a 20-minutes pad-weighing test were performed. The reoperation rates were assessed. The main study outcomes were the objective and subjective cure rates of SUI 1 year after surgery. The objective cure was defined as absence of urinary leakage in the cough stress test and in the 20-minute pad test (pad weight 2 g or less). The subjective cure of SUI was measured by a simple question as to how the patient felt about her incontinence problem after

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treatment. The answer options available were “satisfied” and “dissatisfied.” In our population, patients that reported they were “satisfied” did not want another treatment for SUI. The ones who said they were “dissatisfied” required an additional treatment. The secondary outcome measures included symptom severity evaluation by the Urogenital Distress Inventory Short Form, changes in the Incontinence Quality of Life Questionnaire, and the rate of complications and reoperation. The statistical analysis was performed using the x2 test or Fisher’s exact test for the categorical data. For the numerical variables, the Student’s t test and Mann-Whitney test were used. The generalized estimating equation, analysis of variance, and McNemar’s test were used to compare variables according to the period of analysis. A cutoff point of .05 was considered to be statistically significant. The efficacy was analyzed using a noninferiority test12 considering the null hypothesis transobturator sling—mini-sling 15% or greater, and the alternative hypothesis transobturator sling—mini-sling less than 15%. A noninferiority margin of 15% was adopted on the basis of previous randomized studies comparing transobturator with single-incision slings.13,14 Assessing whether the null hypothesis can be rejected (or, in this case, that the noninferiority margin is met) requires the analysis of the two-sided 90% confidence interval (CI); if the upper bound of the CI of

Enrollment

Assessed for eligibility N=145

Randomized n=130

Allocation

Follow-up

the difference between the transobturator sling and the mini-sling is less than the prespecified noninferiority margin of 15%, the null hypothesis is rejected in favor of the noninferiority of the mini-sling procedure. In a noninferiority test, P,.05 indicates that the study group is not inferior to the control group confirming the study hypothesis, and P values ..05 means that the hypothesis of noninferiority cannot be proven. The intention-to-treat analysis included the total patients who received treatment considering all missing data as failures.15 The per-protocol analysis included only participants who completed the 12-month follow-up. The sample size calculation was performed presuming objective cure rates of 90% for the transobturator sling based on previously published data.16–19 Considering a noninferiority margin of 15%, it was estimated that 50 individuals per group would be needed to detect a difference in cure rates between the two procedures with an 80% power and an a value of .05. Assuming a 10% loss to follow-up rate, the total enrollment goal was 110 patients.

RESULTS One hundred thirty patients were included (Fig. 3). Sixty-nine patients were allocated to the mini-sling group, and 61 patients were assigned to the transobturator tape group. Ten patients were lost to followup, five from each group. At the 12-month follow-up,

Excluded: n=15 • Not meeting inclusion criteria: n=14 • Declined to participate: n=1 • Other reasons: n=0

Allocated to mini-sling: n=69 • Received allocated intervention: 69 • Did not received allocated intervention: 0

Allocated to transobturator sling: n=61 • Received allocated intervention: 61 • Did not received allocated intervention: 0

Lost to follow-up: n=5 • Unable to contact: 3 • Unwilling to continue: 1 • Pregnancy: 1 • Discontinued intervention: 0

Lost to follow-up: n=5 • Unable to contact: 3 • Unwilling to continue: 2 • Discontinued intervention: 0

Fig. 3. Flow diagram of patients throughout the trial. Analysis

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Analyzed: n=64 • Included in intentionto-treat analysis: n=69

Analyzed: n=56 • Included in intentionto-treat analysis: n=61

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120 patients were available for analysis (64 in the mini-sling group and 56 in the transobturator midurethral tape group). Both groups were similar regarding the demographic and clinical variables, as shown in Table 1. Table 2 shows the objective and subjective cure rates. The objective cure rates for the mini-sling and the transobturator sling, considering the intention-totreat analysis, were 68.1% and 81.9% (absolute difference 13.8, 90% CI 1.5–26.1; P5.439). The subjective cure rates for the mini-sling and the transobturator sling were 81.1% and 88.5% (absolute difference 7.4, 90% CI 2.8–17.6; P5.110), respectively. The objective cure rates analyzed per protocol were 73% and 89% (absolute difference 16, 90% CI 4.5–27.1; P5.549), and the subjective cure rates were 87.5% and 96.4% (absolute difference 8.9, 90% CI 0.9–16.8; P5.104), for the mini-sling and the transobturator sling, respectively. When we carefully analyze these data, we can notice that the absolute difference in cure rates between the two procedures was 13.8% for objective cure and 7.4% for the subjective cure using intentionto-treat analysis; and 16% for objective cure and 8.9% for subjective cure using per-protocol analysis. Despite the absolute difference is less than the prespecified margin for noninferiority of 15% (except objective cure in per-protocol analysis), in noninferiority studies, the most important is to analyze the CI. The CI refers to the difference in cure rates between the two procedures. One has to consider the upper limit of the CI. If the upper limit of the CI is above the prespecified margin of 15%, the noninferiority cannot

be demonstrated. If we look carefully at both objective and subjective cure rates, the upper limit of the CI exceeds the noninferiority margin. For the noninferiority test, P values ..05 means that noninferiority cannot be proven. Five patients (7.8%) in the mini-sling group and one patient (1.8%) in the transobturator group who did not achieve objective and subjective cure underwent surgical reintervention and were considered failures. The other patients (12 in the mini-sling group and five in the transobturator group) who did not achieve an objective cure reported improvement and did not want surgical retreatment. They were considered failures as well. A significant reduction in urge symptoms after both surgeries was observed (minisling 35.9% compared with 3.1%, transobturator sling 35.7% compared with 3.5%; P,.001 for both) but without statistically significant differences between the groups (P5.980). Table 3 summarizes the main intra- and postoperative findings. The mean operation time was 5 minutes shorter for the mini-sling procedure (P,.001). Visual analog scale pain scores were similar in both groups. The complications, except thigh pain, were similar in both groups. The number of patients reporting postoperative thigh pain was significantly higher in the transobturator group than in the mini-sling group, four (7.1%) compared with zero (P5.045). Three patients in the mini-sling group had a first postvoid residual urine volume greater than 100 mL and required vesical catheterization. Of those, one patient after a 10-day period had spontaneous voiding and the Foley catheter was removed. One patient had

Table 1. Demographic and Clinical Data Variable Age (y) BMI (kg/m2) Parity Vaginal delivery Cesarean delivery Menopause Previous antiincontinence surgery Urgency symptoms Preoperative Valsalva leak-point pressure value 60 or less (cm H2O) Greater than 60 (cmH2O) Preoperative pad test (g)

Mini-Sling (n564)

Transobturator Sling (n556)

P

54.269.6 27.264.7 3.462 2.662.1 .861 47 (73.4) 12 (18.8) 23 (35.9)

51.9610 28.564.7 3.461.7 2.861.8 .66.8 32 (57.1) 12 (21.4) 20 (35.7)

.206* .161* .915* .548* .291* .092† .891† 1.000†

21 (36.2) 37 (63.8) 24.8624.7

18 (36.7) 31 (63.3) 30.4632.5

1.000† .607‡

BMI, body mass index. Data are mean6standard deviation or n (%) unless otherwise specified. * Student’s t test. † x2 test. ‡ Mann-Whitney test.

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Table 2. Objective and Subjective Cure Rates in the Study Groups Cure Rate Objective cure rate Intention to treat (n5130) Per protocol (n5120) Subjective cure rate Intention to treat (n5130) Per protocol (n5120)

Mini-Sling (%)

Transobturator Sling (%)

Absolute Difference* (90% CI)

P†

47/69 (68.1) 47/64 (73)

50/61 (81.9) 50/56 (89.0)

13.8 (1.5–26.1) 16 (4.5–27.1)

.439 .549

56/69 (81.1) 56/64 (87.5)

54/61 (88.5) 54/56 (96.4)

7.4 (2.8–17.6) 8.9 (.9–16.8)

.110 .104

CI, confidence interval. Data are n/N (%) unless otherwise specified. Intention-to-treat analysis: included the total patients that received treatment, considering all missing data as failures. Per-protocol analysis: included only patients that completed the 12-mo follow-up. * Absolute difference (transobturator sling—mini-sling) and CI, confidence interval for the difference between the two procedures. † Level of significance for the noninferiority test considering a margin of 15%.

a 300-mL postvoid residual urine volume after 1 month, so the tape had to be cut; another patient had a residual urine volume greater than 100 mL until 6 months and required tape resection. Six (9.4%) compared with five (8.9%) women experienced 1-cm tape exposure on the anterior vaginal wall along the suture line within 1 year after surgery. This complication was well managed with

ambulatory resection and topical estrogen therapy. In the early postoperative evaluation, an ecchymosis located in the inner thigh, near the transobturator needle path, was noted in three (5.4%) patients. The ecchymosis measured 4 cm, 6 cm, and the largest was 15 cm in length (Fig. 4). No blood transfusions were required, and prophylactic antibiotics were administered until the process had fully and spontaneously

Table 3. Intraoperative and Postoperative Data Variable Operation time (min) Pain scores (visual analog scale) 24 h Day 7 Intraoperative complications c Anesthesia complications Postoperative complications e Tape exposure g Urinary retention h Ecchymosis i De novo urgency j Urinary tract infection k Thigh pain Reoperation rate Persistent SUI Urinary retention

Mini-Sling (n564)

Transobturator Sling (n556)

P

19.863.24

24.962.63

.000

2.262.7 1.462

2.863.3 1.861.9

.344 b .307

1 (1.6)

1 (1.8)

1.000

6 (9.4) 3 (4.7) 0 (0) 4 (6.3) 18 (28.1) 0 (0)

5 (8.9) 0 (0) 3 (5.4) 4 (7.1) 12 (21.4) 4 (7.1)

1.000 d .247 d .099 d 1.000 f .526 d .045

5 (7.8) 1 (3.1)

1 (1.8) 0 (0)

.213

a

b

d

f

d

SUI, stress urinary incontinence. Data are mean6standard deviation or n (%) unless otherwise specified. Pain scores rated on a visual analog scale from 0 to 10. a Mann-Whitney test. b Student’s t test. c A toxicity reaction with lidocaine and a post-dural puncture headache in the mini-sling group and transobturator group, respectively. d Fisher’s exact test. e Vaginal exposure 1 cm or less. Category 2 A/T3/S1 (International Urogynecological Association and International Continence Society classification). f 2 x test. g Postvoid residual greater than 100 mL measured by vesical catheterization at the postoperative day 1. Category 4B/T1. h Located in the inner thigh, near the transobturator needle path. i Determined by self-report of urgency and by patient’s response to the Urogenital Distress Inventory questions 1 and 2. j Diagnosis made by symptoms associated with leukocyturia in urinalysis between 1 and 12 mo after surgery. k Persistent thigh pain greater than 4–6 wk. Category 6B/T2/S4.

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Analysis of subscales showed also a statistically significant better improvement in social embarrassment in the transobturator group (P5.032). Regarding the Urogenital Distress Inventory Short Form questionnaire, there was an improvement in urinary symptoms after both procedures, although the mean score for the postoperative evaluation was significantly higher in the mini-sling group (patients had more bothersome symptoms in the mini-sling group).

DISCUSSION

Fig. 4. Ecchymosis in the right inner thigh in a patient who underwent the transobturator sling. Djehdian. Single-Incision Mini-Sling for SUI Treatment. Obstet Gynecol 2014.

resolved. Patients presenting groin pain were not the same as those who had ecchymosis. The patients with de novo urgency were successfully treated with anticholinergics. The improvements in the quality of life were assessed with the Incontinence Quality of Life Questionnaire and the Urogenital Distress Inventory Short Form questionnaire. As shown in Table 4, both surgeries provided an improvement in the quality of life on all the Incontinence Quality of Life Questionnaire subscales with a statistically significant difference over time (preoperative compared with postoperative).

In this randomized clinical assay, a noninferiority test was applied to evaluate the efficacy of a new singleincision mini-sling compared with an established transobturator technique. Although the absolute differences in success rates between the two procedures were 13.8% for the objective cure rate and 7.4% for subjective cure rate, when analyzing the CI, the noninferiority of the mini-sling cannot be assumed. Despite these efficacy results, both procedures improved the quality of life, although the analysis of the social embarrassment subscale of the Incontinence Quality of Life Questionnaire showed better improvement in the transobturator group, and the patients had more bothersome urinary symptoms in the mini-sling group. Both methods had few and successfully managed complications. The transobturator approach caused more thigh pain compared with the mini-sling, which could be explained by proximity of the transobturator approach to the nervus obturatorius and peripheral nerve branches. Although not statistically

Table 4. Quality-of-Life Changes P* Quality-of-Life Questionnaires UI-specific quality-of-life instrument scores Avoidance and limiting behavior Mini-sling (n564) Transobturator sling (n556) Psychosocial affect Mini-sling (n564) Transobturator sling (n556) Social embarrassment Mini-sling (n564) Transobturator sling (n556) Urogenital distress inventory short form scores Mini-sling (n564) Transobturator sling (n556)

Preoperative

Postoperative (12 mo)

Between Surgeries

Preoperative 3 Postoperative

Group 3 Period

50.4622.6 51.6613.7

86.8618.1 92.7611.5

.232

.001

.150

64.9624.8 65618.9

93.4615.2 9867.5

.355

.001

.304

42.6622.7 37.5616.3

82.2625.2 91.3617.2

.379

.001

.032

8.562.5 9.362.6

2.763.2 .761.3

.108

.001

.001

UI, urinary incontinence. Data are mean6standard deviation unless otherwise specified. * Statistical analysis with repeated-measures analysis of variance.

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significant, more women required reoperation for persistent SUI in the mini-sling group. The main advantage of the single-incision sling might be the possibility of performing this procedure under local anesthesia with a shorter operation time. The mini-sling is a smaller tape and requires less tissue dissection, and it might exhibit a lower risk of complications because it avoids the transobturator approach. In a clinical prospective study evaluating the Ophira mini-sling,9 Palma et al reported that 88% of the patients were dry, and complications were not observed 12 months after the procedure. It was demonstrated through three-dimensional helical computed tomography reconstruction that the mini-sling is close to the obturator foramen but does not reach it. Angiotomography showed that the mini-sling was distant from the obturator artery, suggesting the safety of the procedure. Various success rates have been reported in comparative studies with single-incision slings. Rui Oliveira et al20 compared the TVT-O, TVT-Secur, and Mini-Arc and reported objective cure rates of 83% after TVT-O, 67% after TVT-Secur, and 87% after Mini-Arc. Tommaselli et al13 and BianchiFerraro et al14 performed noninferiority studies with similar designs and definitions of noninferiority, demonstrating that the single-incision mini-slings were not inferior to the transobturator slings. Fattah et al performed a meta-analysis21 comparing single-incision slings compared with the standard midurethral slings in the surgical management of SUI; they reported that the single-incision slings were associated with significantly lower patient-reported and objective cure rates compared with the standard midurethral slings. This wide range of results and a disagreement about whether mini-slings are as effective as standard midurethral slings can be explained by a lack of procedure standardization, because several different devices have been developed with different types of polypropylene mesh-anchoring systems. The strength of this study lies in its design. It is a prospective, two-arm, randomized study with an active control group for comparison and a noninferiority analysis. The noninferiority trial is appropriate for the evaluation of the efficacy of a new treatment compared with an active control when it is hypothesized that the new treatment may not be superior to a proven effective treatment but is clinically and statistically not inferior in effectiveness.12 An additional strength of the study lies in the 1-year follow-up and postoperative outcomes that are based on objective and subjective evaluations,

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although the subjective outcome is based on a nonvalidated measure. The limitations of the study included the nonblinded design. In this trial, blinding process was not feasible as a result of the different anesthesia used for the procedures and also attributable to issues of the skin incisions. Different anesthesia techniques and concurrent perineorrhaphy in some patients might have jeopardized the postoperative pain assessment. Because the sample size was calculated for the efficacy analysis with the noninferiority test, it may be underpowered to assess secondary outcomes including complication rates. Cystoscopy was performed in the operating room only if any tissue injury was suspected or during follow-up in the presence of severe and persistent irritative urinary symptoms or recurrent urinary tract infection. Most of the studies on transobturator and mini-sling techniques do not use intraoperative cystoscopy because the trajectory of the trocars makes bladder and urethral injury highly unlikely.22 All investigators received procedure-specific training before their first mini-sling placement. Although the surgeons were experienced, there might have been a learning curve within the earlier cases. The results of this study may in part reflect this learning curve effect once the objective success rate for the first 32 patients who underwent the mini-sling procedure was 69% and the objective success rate for the last 32 patients was 77% (P5.485). In conclusion, in terms of efficacy, the noninferiority of the mini-sling could not be demonstrated in this study at the 12-month follow-up. The mini-sling was associated with significantly shorter operative time and less postoperative persistent thigh pain. REFERENCES 1. Haylen BT, de Ridder D, Freeman RM, Swift SE, Berghmans B, Lee J, et al; International Urogynecological Association; International Continence Society. An International Urogynecological Association (IUGA)/International Continence Society (ICS) joint report on the terminology for female pelvic floor dysfunction. Neurourol Urodyn 2010;29:4–20. 2. Paraiso MF, Walters MD, Karram MM, Barber MD. Laparoscopic Burch colposuspension versus tension-free vaginal tape: a randomized trial. Obstet Gynecol 2004;104:1249–58. 3. Cox A, Herschorn S, Lee L. Surgical management of female SUI: is there a gold standard? Nat Rev Urol 2013;10:78–89. 4. Kondo A, Isobe Y, Kimura K, Kamihira O, Matsuura O, Gotoh M, et al. Efficacy, safety and hospital costs of tensionfree vaginal tape and pubovaginal sling in the surgical treatment of stress incontinence. J Obstet Gynaecol Res 2006;32:539–44. 5. Hahn I, Fall M. Objective quantification of stress urinary incontinence: a short, reproducible, provocative pad-test. Neurourol Urodyn 1991;10:475–81.

Single-Incision Mini-Sling for SUI Treatment

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14. Bianchi-Ferraro AM, Jarmy-Di Bella ZI, Castro RD, Bortolini MA, Sartori MG, Girão MJ. Single-incision sling compared with transobturator sling for treating stress urinary incontinence: a randomized controlled trial. Int Urogynecol J 2013; 24:1459–65. 15. Gupta SK. Intention-to-treat concept: a review. Perspect Clin Res 2011;2:109–12. 16. Aniuliene R. Tension-free vaginal tape versus tension-free vaginal tape obturator (inside-outside) in the surgical treatment of female stress urinary incontinence. Medicina (Kaunas) 2009;45: 639–43. 17. Cordeiro A, Lermann R, Grilo I, Martins A, Moniz L. [Transobturator tapes for stress urinary incontinence treatment: middle-term results] [in Portuguese]. Acta Med Port 2010;23: 589–96. 18. De Ridder D, Berkers J, Deprest J, Verguts J, Ost D, Hamid D, et al. Single incision mini-sling versus a transobturator sling: a comparative study on MiniArc and Monarc slings. Int Urogynecol J 2010;21:773–8. 19. Yang X, Jiang M, Chen X, Tong X, Li H, Qiu J, et al. TVT-O vs. TVT for the treatment of SUI: a non-inferiority study. Int Urogynecol J 2012;23:99–104. 20. Oliveira R, Botelho F, Silva P, Resende A, Silva C, Dinis P, et al. Exploratory study assessing efficacy and complications of TVT-O, TVT-Secur, and Mini-Arc: results at 12-month followup. Eur Urol 2011;59:940–4. 21. Abdel-Fattah M, Ford JA, Lim CP, Madhuvrata P. Singleincision mini-slings versus standard midurethral slings in surgical management of female stress urinary incontinence: a meta-analysis of effectiveness and complications. Eur Urol 2011;60:468–80. 22. Abdel-Fattah M, Ramsay I, Pringle S. Lower urinary tract injuries after transobturator tape insertion by different routes: a large retrospective study. BJOG 2006;113:1377–81.

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Single-Incision Mini-Sling for SUI Treatment

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Transobturator sling compared with single-incision mini-sling for the treatment of stress urinary incontinence: a randomized controlled trial.

To determine the efficacy and safety of a single-incision mini-sling compared with a transobturator midurethral sling for stress urinary incontinence ...
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