World J Urol DOI 10.1007/s00345-014-1418-y
ORIGINAL ARTICLE
Pelvic floor muscle function is an independent predictor of outcome after retrourethral transobturator male sling procedure Irina Soljanik · Ricarda M. Bauer · Christian G. Stief · Christian Gozzi · Armin J. Becker
Received: 16 September 2014 / Accepted: 7 October 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose To evaluate the impact of the retrourethral transobturator sling (RTS) on pelvic floor muscle function (PFMF) and whether preoperative PFMF is associated with RTS outcome. Methods Between May 2008 and December 2010, 59 consecutive men with postprostatectomy stress urinary incontinence (PSUI) underwent PFMF assessment before RTS and 6 months thereafter in a prospective cohort study. The assessments included demographic and clinical characteristics, and quality of life (QoL) questionnaires. PFMF was evaluated by digital rectal examination on the modified 6-point Oxford scale and by surface electromyography. The primary outcome measurement was success after RTS defined as PSUI cure with use of no or one dry “security” pad. For secondary outcome, PFMF, 1-h pad test, and impact of PSUI on QoL were evaluated. Uni- and multivariate analyses were performed. Results After 6-month follow-up, the cure, improvement (>50 % pad reduction) and failure rates were 50 % (29/58 patients), 24 % (14/58 patients) and 26 % (15/58 patients), respectively. Significant improvement of QoL, clinical and PFMF parameters occurred after RTS. On multivariate analysis, weak PFMF (OR 86.29) and greater muscle fatigue (OR 3.31) were significant independent predictors of RTS failure. The final model demonstrated good I. Soljanik · R. M. Bauer · C. G. Stief · C. Gozzi · A. J. Becker Department of Urology, University Hospital Grosshadern, Ludwig-Maximilians-University, Munich, Germany I. Soljanik (*) Neuro-Urology, Spinal Cord Injury Center, Heidelberg University Hospital, Schlierbacher Landstrasse 200a, 69118 Heidelberg, Germany e-mail: [email protected]
calibration (p = 0.882) and excellent discriminative ability (0.942, 95 % CI 0.883–1.0) to predict success after RTS. Conclusions PFMF improved significantly after RTS procedure. Higher muscle fatigue and weak PFMF were independent predictors of RTS failure. Digital rectal evaluation of PFMF is a simple and reliable clinical tool, which can be used by urologists in daily routine to predict the RTS outcome. Keywords Male sling · Male incontinence · Pelvic floor muscle function · Postprostatectomy incontinence · Retrourethral transobturator sling
Introduction Postprostatectomy stress urinary incontinence (PSUI) still remains one of the significant complications with negative impact on quality of life (QoL). Large variation in reported PSUI rates between 1 and 57 % [1] is explained by multifactorial etiology, different definitions and assessments of PSUI [2, 3]. Pelvic floor muscle training (PFMT) is widely used in PSUI patients to improve pelvic floor muscle function (PFMF) [4]. However, the benefit of PFMT on PSUI remains uncertain [5]. The retrourethral transobturator sling (RTS) is one of the minimally invasive procedures for PSUI treatment after failed or incomplete conservative therapy [2, 4]. RTS relocates the external urethral sphincter (EUS) and its supporting structures into a preprostatectomy position to regain continence [6]. Patients with mild or moderate PSUI and good residual EUS function seem to be optimal candidates to achieve continence after RTS [7, 8]. However, RTS failure rates still range between 20 and 45 % [9]. Usable tools for the preoperative diagnostics to predict RTS failure are limited.
13
The aim of this study was to evaluate the impact of RTS on PFMF and whether preoperative PFMF is predictive of RTS outcome.
World J Urol
re-evaluated. RTS cure was defined as use of no or one dry “security” pad, and improvement as a reduction of pads by ≥50 %. PFMF assessment
Materials and methods Study design and patients Between May 2008 and December 2010, 59 PSUI patients were consecutively recruited from our outpatient clinic in a continuous prospective cohort study. All patients signed the informed consent form after ethical approval by the local institutional review board. PSUI patients who intended to undergo RTS (AdVance®, American Medical Systems, Minnetonka, MN), met the previously reported criteria for RTS implantation [10] and agreed on pre- and postoperative PFMF evaluations, were included in the study. Other inclusion criteria were a history of localized prostate cancer, prostate size of ≤40 cm3, PFMT after RP for at least 3 months, and good residual EUS function confirmed by the repositioning test [11–13]. Exclusion criteria were a history of transurethral prostate resection, surgical therapy of incontinence, anastomotic/ urethral stricture, adjuvant radiotherapy, post-void residual urine volume (PVR) >100 ml, self-reported overactive bladder symptoms, detrusor overactivity in urodynamics, fixed or scarred EUS in urethroscopy and contraindications for surface electromyography (s-EMG) such as pacemaker, allergy to s-EMG-electrodes or gel, dermatological conditions (e.g., eczema, dermatitis), hemorrhoids and anal fissures. Clinical evaluation The preoperative workup for RTS implantation included demographics, evaluation of medical history, uroflowmetry, residual urine (PVR), daily pad use, 1-h pad test, urodynamics with abdominal leak point pressure (ALPP) measurement and urethrocystoscopy with repositioning test [11–13]. The severity of incontinence was evaluated by the number of daily pads used, 1-h pad test [10, 11] and the International Consultation on Incontinence QuestionnaireShort Form (ICIQ-SF; range 0–21, minimal to maximum symptoms) [14]. The PSUI impact on QoL was assessed by the Incontinence Quality of Life (I-QOL; scale: 0–100, higher score represents better QoL) questionnaire [15] and ICIQ-SF. RTS was implanted under general or spinal anesthesia by one well-trained surgeon (C.G.) using the surgical technique previously reported [6, 10]. After 6-month follow-up, daily pad use, 1-h pad test, PVR, uroflowmetry, ICIQ-SF, I-QOL and PFMF were
13
First, patients were given structured information about PFM anatomy and PFM function with literal instruction to “squeeze and lift” the pelvic floor on expiration and to avoid intentional use of abdominal, gluteal or hip muscles for correct PFM contraction [16, 17]. PFMF was evaluated by digital rectal examination (DRE) and, after 5-min rest, by perineal and anal s-EMG in patients lying in lateral position with slightly angled knees. After connection of perineal and anal electrodes to s-EMG unit (ProElektroden®, 50 × 50 mm, RMS-3®, ProCept®-Unit, Innocept Medizintechnik, Gladbeck, Germany) operating at voltage between 0 and 250 µV and providing a band-pass filter for 50 Hz, s-EMG was performed. ProDoc®-Software (Innocept Medizintechnik, Gladbeck, Germany) was used for s-EMG data analysis. The ability to perform a correct maximum voluntary contraction (MVC) on demand was assessed by visual observation, DRE and s-EMG in accordance with the terminology of the International Continence Society (ICS) [18]. Prior to the data collection, correct MVC was verified by s-EMG as at least three to four times higher muscle tone compared to the baseline at rest. PFMF was assessed according to the PERFECT scheme [19]. PFM strength was measured by DRE on the modified 6-point Oxford scale [16, 19] and by s-EMG as a highest value of three times repeated 10-s MVCs with 1-min rest in-between. To evaluate PFM slow-twitch fibers activity, the area under the EMG-curve (AUC) and PFM fatigue were assessed [19]. AUC was recorded by DRE in seconds and by s-EMG in µV*s as a 10-s sustained MVC with maximal acceptable strength reduction of 30 % without contraction of abdominal, gluteal or hip muscles. PFM fatigue was measured as a number of repetitions (up to 10) of a 10-s MVC with 4-s rest between each contraction. After a 1-min rest and instruction of patients to contract and relax their PFM as quickly and strongly as possible, fast-twitch fibers activity of PFM was assessed as a number (up to 10) of onesecond MVCs with one-second rest in-between [19]. DRE of PFM was independently performed in all patients by a physiotherapist at s-EMG visit and a urologist before urodynamics to assess the inter-rater reliability. The order of evaluations was randomized to eliminate a systematic bias. The assessors were well trained in PFM evaluations. To ensure the intra-rater reliability, the same assessor repeated DRE and s-EMG in a random sample of 20 patients 4 weeks after the first measurement. The Oxford scale was dichotomized into weak and intact PFMF to
World J Urol
assess the reliability and simplify the evaluation of PFM for everyday clinical practice. No (score = 0), flicker (score = 1) or weak (score = 2) 10-s MVC as assessed on the modified 6-point Oxford scale [16, 19] by DRE was defined as a weak PFMF. Otherwise, an intact PFMF (Oxford score ≥ 3) was assumed. The primary outcome measurement was success after RTS defined as a cure. Otherwise, failure was considered. Secondary outcome measurements included evaluation of PFMF, 1-h pad test, impact of PSUI on QoL. Statistics The sample size was calculated using the G*Power statistical power analysis program (v. 3.1.7, free software written by F. Faul, University of Kiel, Germany). Considering RTS cure rates ranging between 40 % [6] and 60 % [20], the effect size of 0.2, a type 1 error (p
ORIGINAL ARTICLE
Pelvic floor muscle function is an independent predictor of outcome after retrourethral transobturator male sling procedure Irina Soljanik · Ricarda M. Bauer · Christian G. Stief · Christian Gozzi · Armin J. Becker
Received: 16 September 2014 / Accepted: 7 October 2014 © Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose To evaluate the impact of the retrourethral transobturator sling (RTS) on pelvic floor muscle function (PFMF) and whether preoperative PFMF is associated with RTS outcome. Methods Between May 2008 and December 2010, 59 consecutive men with postprostatectomy stress urinary incontinence (PSUI) underwent PFMF assessment before RTS and 6 months thereafter in a prospective cohort study. The assessments included demographic and clinical characteristics, and quality of life (QoL) questionnaires. PFMF was evaluated by digital rectal examination on the modified 6-point Oxford scale and by surface electromyography. The primary outcome measurement was success after RTS defined as PSUI cure with use of no or one dry “security” pad. For secondary outcome, PFMF, 1-h pad test, and impact of PSUI on QoL were evaluated. Uni- and multivariate analyses were performed. Results After 6-month follow-up, the cure, improvement (>50 % pad reduction) and failure rates were 50 % (29/58 patients), 24 % (14/58 patients) and 26 % (15/58 patients), respectively. Significant improvement of QoL, clinical and PFMF parameters occurred after RTS. On multivariate analysis, weak PFMF (OR 86.29) and greater muscle fatigue (OR 3.31) were significant independent predictors of RTS failure. The final model demonstrated good I. Soljanik · R. M. Bauer · C. G. Stief · C. Gozzi · A. J. Becker Department of Urology, University Hospital Grosshadern, Ludwig-Maximilians-University, Munich, Germany I. Soljanik (*) Neuro-Urology, Spinal Cord Injury Center, Heidelberg University Hospital, Schlierbacher Landstrasse 200a, 69118 Heidelberg, Germany e-mail: [email protected]
calibration (p = 0.882) and excellent discriminative ability (0.942, 95 % CI 0.883–1.0) to predict success after RTS. Conclusions PFMF improved significantly after RTS procedure. Higher muscle fatigue and weak PFMF were independent predictors of RTS failure. Digital rectal evaluation of PFMF is a simple and reliable clinical tool, which can be used by urologists in daily routine to predict the RTS outcome. Keywords Male sling · Male incontinence · Pelvic floor muscle function · Postprostatectomy incontinence · Retrourethral transobturator sling
Introduction Postprostatectomy stress urinary incontinence (PSUI) still remains one of the significant complications with negative impact on quality of life (QoL). Large variation in reported PSUI rates between 1 and 57 % [1] is explained by multifactorial etiology, different definitions and assessments of PSUI [2, 3]. Pelvic floor muscle training (PFMT) is widely used in PSUI patients to improve pelvic floor muscle function (PFMF) [4]. However, the benefit of PFMT on PSUI remains uncertain [5]. The retrourethral transobturator sling (RTS) is one of the minimally invasive procedures for PSUI treatment after failed or incomplete conservative therapy [2, 4]. RTS relocates the external urethral sphincter (EUS) and its supporting structures into a preprostatectomy position to regain continence [6]. Patients with mild or moderate PSUI and good residual EUS function seem to be optimal candidates to achieve continence after RTS [7, 8]. However, RTS failure rates still range between 20 and 45 % [9]. Usable tools for the preoperative diagnostics to predict RTS failure are limited.
13
The aim of this study was to evaluate the impact of RTS on PFMF and whether preoperative PFMF is predictive of RTS outcome.
World J Urol
re-evaluated. RTS cure was defined as use of no or one dry “security” pad, and improvement as a reduction of pads by ≥50 %. PFMF assessment
Materials and methods Study design and patients Between May 2008 and December 2010, 59 PSUI patients were consecutively recruited from our outpatient clinic in a continuous prospective cohort study. All patients signed the informed consent form after ethical approval by the local institutional review board. PSUI patients who intended to undergo RTS (AdVance®, American Medical Systems, Minnetonka, MN), met the previously reported criteria for RTS implantation [10] and agreed on pre- and postoperative PFMF evaluations, were included in the study. Other inclusion criteria were a history of localized prostate cancer, prostate size of ≤40 cm3, PFMT after RP for at least 3 months, and good residual EUS function confirmed by the repositioning test [11–13]. Exclusion criteria were a history of transurethral prostate resection, surgical therapy of incontinence, anastomotic/ urethral stricture, adjuvant radiotherapy, post-void residual urine volume (PVR) >100 ml, self-reported overactive bladder symptoms, detrusor overactivity in urodynamics, fixed or scarred EUS in urethroscopy and contraindications for surface electromyography (s-EMG) such as pacemaker, allergy to s-EMG-electrodes or gel, dermatological conditions (e.g., eczema, dermatitis), hemorrhoids and anal fissures. Clinical evaluation The preoperative workup for RTS implantation included demographics, evaluation of medical history, uroflowmetry, residual urine (PVR), daily pad use, 1-h pad test, urodynamics with abdominal leak point pressure (ALPP) measurement and urethrocystoscopy with repositioning test [11–13]. The severity of incontinence was evaluated by the number of daily pads used, 1-h pad test [10, 11] and the International Consultation on Incontinence QuestionnaireShort Form (ICIQ-SF; range 0–21, minimal to maximum symptoms) [14]. The PSUI impact on QoL was assessed by the Incontinence Quality of Life (I-QOL; scale: 0–100, higher score represents better QoL) questionnaire [15] and ICIQ-SF. RTS was implanted under general or spinal anesthesia by one well-trained surgeon (C.G.) using the surgical technique previously reported [6, 10]. After 6-month follow-up, daily pad use, 1-h pad test, PVR, uroflowmetry, ICIQ-SF, I-QOL and PFMF were
13
First, patients were given structured information about PFM anatomy and PFM function with literal instruction to “squeeze and lift” the pelvic floor on expiration and to avoid intentional use of abdominal, gluteal or hip muscles for correct PFM contraction [16, 17]. PFMF was evaluated by digital rectal examination (DRE) and, after 5-min rest, by perineal and anal s-EMG in patients lying in lateral position with slightly angled knees. After connection of perineal and anal electrodes to s-EMG unit (ProElektroden®, 50 × 50 mm, RMS-3®, ProCept®-Unit, Innocept Medizintechnik, Gladbeck, Germany) operating at voltage between 0 and 250 µV and providing a band-pass filter for 50 Hz, s-EMG was performed. ProDoc®-Software (Innocept Medizintechnik, Gladbeck, Germany) was used for s-EMG data analysis. The ability to perform a correct maximum voluntary contraction (MVC) on demand was assessed by visual observation, DRE and s-EMG in accordance with the terminology of the International Continence Society (ICS) [18]. Prior to the data collection, correct MVC was verified by s-EMG as at least three to four times higher muscle tone compared to the baseline at rest. PFMF was assessed according to the PERFECT scheme [19]. PFM strength was measured by DRE on the modified 6-point Oxford scale [16, 19] and by s-EMG as a highest value of three times repeated 10-s MVCs with 1-min rest in-between. To evaluate PFM slow-twitch fibers activity, the area under the EMG-curve (AUC) and PFM fatigue were assessed [19]. AUC was recorded by DRE in seconds and by s-EMG in µV*s as a 10-s sustained MVC with maximal acceptable strength reduction of 30 % without contraction of abdominal, gluteal or hip muscles. PFM fatigue was measured as a number of repetitions (up to 10) of a 10-s MVC with 4-s rest between each contraction. After a 1-min rest and instruction of patients to contract and relax their PFM as quickly and strongly as possible, fast-twitch fibers activity of PFM was assessed as a number (up to 10) of onesecond MVCs with one-second rest in-between [19]. DRE of PFM was independently performed in all patients by a physiotherapist at s-EMG visit and a urologist before urodynamics to assess the inter-rater reliability. The order of evaluations was randomized to eliminate a systematic bias. The assessors were well trained in PFM evaluations. To ensure the intra-rater reliability, the same assessor repeated DRE and s-EMG in a random sample of 20 patients 4 weeks after the first measurement. The Oxford scale was dichotomized into weak and intact PFMF to
World J Urol
assess the reliability and simplify the evaluation of PFM for everyday clinical practice. No (score = 0), flicker (score = 1) or weak (score = 2) 10-s MVC as assessed on the modified 6-point Oxford scale [16, 19] by DRE was defined as a weak PFMF. Otherwise, an intact PFMF (Oxford score ≥ 3) was assumed. The primary outcome measurement was success after RTS defined as a cure. Otherwise, failure was considered. Secondary outcome measurements included evaluation of PFMF, 1-h pad test, impact of PSUI on QoL. Statistics The sample size was calculated using the G*Power statistical power analysis program (v. 3.1.7, free software written by F. Faul, University of Kiel, Germany). Considering RTS cure rates ranging between 40 % [6] and 60 % [20], the effect size of 0.2, a type 1 error (p
