Investigation of the multivectorial load distribution of the pelvic floor in different female populations

Author(s)

Licia Pazzoto Cacciari

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2017-08-09

Examining board members

Isabel de Camargo Neves Sacco; Chantale Dumoulin; Jefferson Fagundes Loss

• Advisor: Isabel de Camargo Neves Sacco

Abstract

This thesis is presented as a compilation of two scientific papers accepted for publication, reproduced in different sections. The general purpose of this thesis is to develop a novel instrumented probe for pelvic floor muscle (PFM) biomechanics assessment, capable of providing a precise high spatial 3D resolution pressure profile of the vaginal canal, and to map the spatial coordination potential of these muscles in a trained female population. For the first objective, we developed a novel device for assessing the spatiotemporal pressure profile of the vaginal canal. The pressure profile was (i) tested for reliability and repeatability, (ii) compared to the PFM digital assessment, and (iii) characterized and compared between two opposite tasks: maximum contraction and Valsalva maneuver (maximum intra-abdominal effort with downward movement of the pelvic floor). For the second objective, we assessed and compared two groups of asymptomatic women using the newly developed device: practitioners and non-practitioners of a specific coordination training of the PFM, the Pompoir technique. The developed probe consists of a non-deformable Ertacetal® cylinder, covered by a matrix of individually calibrated capacitive sensors (MLA-P1, pliance System; Novel, Munich, Germany). The cylinder is 23.2 mm in diameter and 8 cm in length, and its sensing area is 70.7 mm2 (10x10 matrix of sensing elements, each with 7.07 mm2 in size and 1.79 mm gap between them). The capacitive sensors have a measurement range of 0.5-100kPa, and a measurement resolution of 0.42 kPa, enabling unidirectional measurements with high spatial resolution, and tested low uniform and linear response to temperature variations. The pressure profile was described based on two different approaches, either considering the peak pressure of the entire sensor matrix or the pressure distribution along different sub-regions of the vaginal canal, obtained by divisions of the sensor matrix in \"rings\", \"planes\" or major areas (caudal, mid and cranial) throughout the vaginal length. Intraclass correlation coefficients indicated excellent inter- and intra-rater reliability and intra-trial repeatability for the total and mid-areas, with moderate reliability for the cranial and caudal areas. There was a moderate correlation between peak pressure and PFM digital palpation [Spearman\'s coefficient r=0.55 (p < 0.001)]. Spatiotemporal profiles were completely different between the maximum contraction tasks compared to Valsalva (2-way ANOVAs for repeated measures), with contraction resulting in notably higher pressures in the mid-anteroposterior portion of the vaginal canal. Regarding the effect of Pompoir training, the trained group presented better ability to sustain the achieved pressure for a longer period (40% longer, moderate effect, P=0.04) also having smaller relative contributions from the mid-region rings and anteroposterior plane, and greater contributions from the caudal and cranial rings and latero-lateral plane, with more symmetrical pressure distribution patterns in comparison to the control group. With this protocol and novel instrument, we obtained a high-resolution and highly reliable innovative 3D pressure distribution map of the pelvic floor, capable of distinguishing vaginal sub-regions, planes, rings, tasks and characterizing coordination patterns of the PFM following a specific training protocol (AU)

• FAPESP's process: 13/13820-6 - The influence of perineal training and type of delivery on multidirectional load distribution of the female pelvic floor
• Grantee: Licia Pazzoto Cacciari
• Support Opportunities: Scholarships in Brazil - Doctorate