A majority of patients (up to 87%) experience moderate-to-severe urinary incontinence (UI) after early radical prostatectomy (1). Pelvic floor muscle training (PFMT) is the most commonly recommended conservative treatment for post-prostatectomy UI (PP-UI) (1). In addition to strength and endurance training, conscious precontraction of the pelvic floor muscles (Knack maneuver) can also be taught in PFMT (2). Another widely recommended approach in the management of UI is lifestyle recommendations (3). However, the evidence for these recommendations is quite limited (3). The aim of this study was to reveal the additional effects of the Knack maneuver and lifestyle recommendations to PFMT in PP-UI in a randomized controlled design.

The present study was designed as a prospective randomized-controlled study and included three parallel arms (Group I: PFMT with knack maneuver and lifestyle recommendations, Group II: PFMT with knack maneuver, and Group III: PFMT alone). After the detailed screening, individuals with PP-UI and those having no cooperation problems were included in the study. Exclusion criteria were the presence of acute disease, acute prostatectomy surgery (within the first 3 weeks after prostatectomy), neurological disease or neurogenic bladder, pure urgency UI, pre-operative incontinence, and previous bladder or other prostate surgeries. A computer-based block randomization procedure was used to assign blocks of six participants to each study arm.
Firstly, standardized home-based PFMT protocols were performed in all study groups. Anal palpation was used to teach different types of PFM contractions. A total of 40 contractions (10 fast, 10 sustained, and 20 submaximal) were performed in 3 sessions per day for 8 weeks. All individuals were asked to come for clinical visit every 2 weeks, to monitor exercise accuracy and compliance. The exercise program was intensified by increasing the number of contractions. In Group I and II, the Knack maneuver was instructed to be performed during daily activities that cause UI episodes. Lastly, within the scope of comprehensive lifestyle recommendations, information about UI-related medical conditions, possible factors contributing to UI (diet, fluid intake, constipation, smoking, medications, and exercise), and implications and coping strategies were provided. A written document containing all of the information was provided to the individuals in Group I.
The primary outcome measure was the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI SF) score. Secondary outcome measures included the 1-hour pad test, King's Health Questionnaire (KHQ), and the assessments of the Patient Global Impression of Severity and Improvement (PGI-S and PGI-I). Exercise diaries were given to all individuals to increase and monitor exercise compliance.
Kruskal Wallis test was used to compare the data of the 3 study groups. When the difference between the groups was revealed, the Mann Whitney-U test and Bonferroni correction were used for pairwise group comparisons (p<0.017). Wilcoxon test was used in the analysis of within-group changes. Alpha was set at 0.05.

A total of 52 men who had PP-UI symptoms (age: 64.04±6.98 years, BMI: 27.29± 3.56 kg/m2) were included in this study. There were no statistically significant differences between groups in terms of the descriptive characteristics and baseline outcome measures (p>0.05). Adherences to PFMT were also similar between groups (p>0.05).

At the end of the 8th week, the effect sizes of the changes in the primary outcome (ICIQ-UI SF) within study groups were 1.9, 1.1, and 1.2, respectively. According to the two-way hypothesis design, the post-hoc power rates were 99%, 95%, and 99%, respectively, with a type I error rate of 5%.

At the end of week 8, there were statistically significant improvements in all outcome measures compared to baseline in all study groups, except for some KHQ subdomain scores and PGI-I scores (p<0.05). However, Group I had significant improvements in all of the KHQ subdomain scores (Table 1).

In the inter-group comparisons of the changes, there was a difference in terms of improvement in ICIQ-UI SF, KHQ role limitations, physical limitations, emotional problems subdomains, and PGI-S scores (p<0.05), while there was no difference between the groups in the 1-hour pad test, other KHQ subdomain scores, and PGI-I scores (p>0.05). According to pairwise comparisons, Group I (PFMT+Knack maneuver+lifestyle recommendations) showed greater improvement in the specified parameters (ICIQ-UI SF, KHQ role limitations, physical limitations, emotional problems subdomains, and PGI-S score) than the other groups.

This is the first RCT comparing the effect of PFMT, in combination with the Knack maneuver and lifestyle recommendations in the management of PP-UI. The findings from the present study showed that adding the Knack maneuver alone to PFMT did not provide any additional effect on the management of PP-UI. On the other hand, triple combination of PFMT with a Knack maneuver and comprehensive lifestyle recommendations seems to be more effective than PFMT alone and a dual approach combination (PFMT+Knack maneuver) in reducing the subjective severity of urinary loss and improving quality of life. The fact that there was no difference between the groups in the objective incontinence severity measured by the 1-hour pad test may be related to the relatively short duration of the test (compared to the 24-hour pad test). Although the 1-hour pad test is time-saving and cost-effective for the measurement of urinary leakage, the major disadvantage of this test is considered that it gives limited information on leakage conditions during the routine daily activities of individuals.

In the treatment of PP-UI, better results can be obtained if PFMT is combined with training on the knack maneuver and comprehensive lifestyle recommendations. In future studies, the objective severity of UI can be evaluated over a wider period of time. Long-term follow-up is also needed in further studies.

Kretschmer A, Hubner W, Sandhu JS, Bauer RM. Evaluation and Management of Postprostatectomy Incontinence: A Systematic Review of Current Literature. Eur Urol Focus. 2016;2(3):245-59.
Miller J, Ashton-Miller J, DeLancey JJNU. The Knack: use of precisely-timed pelvic muscle contraction can reduce leakage in SUI. 1996;15(4):392-3.
Imamura M, Williams K, Wells M, McGrother CJCDoSR. Lifestyle interventions for the treatment of urinary incontinence in adults. 2015(12).

Continence 2S2 (2022) 100354
DOI: 10.1016/j.cont.2022.100354