Pelvic floor and abdominal muscles' morphological and functional assessment in continent and stress urinary incontinent women

Author(s)

Natalia Miguel Martinho

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2020-02-21

Examining board members

Cássio Luís Zanettini Riccetto; Luiz Gustavo Oliveira Brito; Cristine Homsi Jorge Ferreira; Lígia de Sousa Marino

• Advisor: Simone Botelho; Cássio Luís Zanettini Riccetto

Abstract

Introduction: Stress urinary incontinence (SUI) is characterized by urinary loss during situations that result in increased intra-abdominal pressure. Although its pathophysiology is not yet fully elucidated, alterations in the pelvic floor muscles’ (PFM) morphology and function seems to be important predisposing factors. Additionally, the interaction between the PFM and other abdominopelvic muscles (especially the transverse abdominal - TrA and internal oblique - IO muscles) also seems to have a strong influence on female urinary continence mechanisms. Aim: This study proposed: 1. To investigate the agreement between the results of four-dimensional translabial ultrasound (4D TLUS) with digital palpation and surface electromyography (sEMG); 2. To verify the PFM morphological and functional changes that are presented by SUI women; 3. To investigate the effect of pelvic floor and abdominal muscles’ contraction on PFM morphology and abdominal muscles thickness, in continent and incontinent women; and 4. To compare the pelvic floor and TrA/IO muscles’ percentage of co-contraction between continent and incontinent women. Methods: Two hundred and seventy-nine women were initially recruited. The included volunteers were submitted to an anamnesis for personal, sociodemographic and obstetric data collection. Urinary continence status was ascertained by the International Consultation on Incontinence Questionnaire - Urinary Incontinence - Short Form. Then, the participants were submitted to a PFM physical evaluation by means of digital palpation (graded by the PERFECT scale), sEMG and 4D TLUS. The abdominal muscles assessment was performed by means of sEMG and 2D transabdominal ultrasound. The sEMG and ultrasound evaluation protocols consisted on the acquisition of electrical signals and ultrasound images in four situations: at rest, during PFM contraction, abdominal contraction and simultaneous PFM and abdominal contraction. A significance level of 5% was adopted in the statistical analysis. Results: The results were divided into four manuscripts related to the proposed objectives: 1. The levator plate angle was the ultrasound parameter that best associated with the digital palpation (p<.0001) and sEMG (p=0.04 and r=0.1); 2. SUI women presented larger genital hiatus area (p=0.007), lower bladder neck position (p=0.0006) and thinner puborectalis muscle thickness (p=0.03); as well as lower PFM strength (p<.0001), endurance (p=0.006), resistance (p=0.02) and coordination (p=0.0003); in addition to the simultaneous accessory muscles co-contraction (p<.0001), when compared to continent women; 3. The isolated PFM contraction did not promoted a significant change on abdominal muscles thickness, as the direct abdominal contraction did in both groups. On the other hand, continent women showed a significant puborectalis muscle thickening during abdominal contraction (p<.0001), as opposed to incontinent women; 4. Continent women presented greater activation of TrA/IO during voluntary PFM contraction (p=0.01); as well as greater PFM activation during voluntary TrA/IO contraction (p<0.001), than incontinent women. Conclusion: Considering that both PFM morphology and function, as well as the PFM and TrA co-contraction pattern, are impaired in SUI women, it is important to use reliable assessment methods that allow a comprehensive understanding of PFM function, not restricting the evaluation only on one single method and/or restricting only on PFM assessment (AU)

• FAPESP's process: 15/22521-8 - Co-activation analysis between the abdominal and pelvic floor muscles and its relationship with the pelvic floor's ultrasound biometric parameters in women with predominantly stress urinary incontinence
• Grantee: Natalia Miguel Martinho Fogaça
• Support Opportunities: Scholarships in Brazil - Doctorate