Urethral lumen occlusion by artificial sphincteric devices: a computational biomechanics approach.
The action induced by artificial sphincteric devices to provide urinary continence is related to the problem of evaluating the interaction between the occlusive cuff and the urethral duct. The intensity and distribution of the force induced within the region of application determine a different occlusion process and potential degradation of the urethral tissue, mostly at the borders of the cuff. This problem is generally considered in the light of clinical and surgical operational experience, while a valid cooperation is established with biomechanical competences by means of experimental and numerical investigation. A three-dimensional model of the urethra is proposed aiming at a representation of the phases of the urethral occlusion through artificial sphincters. Different conformations of the cuff are considered, mimicking different loading conditions in terms of force intensity and distribution and consequent deformation caused in soft tissues. The action induced in the healthy urethra is investigated, as basis for an evaluation of the efficacy and reliability of the sphincteric devices. The problem is characterized by coupled nonlinear geometric and material problem and entails a complex constitutive formulation. A heavy computational procedure is developed by means of analyses that operate within an explicit finite element formulation. Results reported outline the overall response of the urethral duct during lumen occlusion, leading to an accurate description of the phenomenon in the different phases.
Department of Industrial Engineering, University of Padova, Padova, Italy. arturo.natali@unipd.it.|Centre for Mechanics of Biological Materials, University of Padova, Padova, Italy. arturo.natali@unipd.it.
Arturo Nicola
AN
Natali
Department of Industrial Engineering, University of Padova, Padova, Italy.|Centre for Mechanics of Biological Materials, University of Padova, Padova, Italy.
Emanuele Luigi
EL
Carniel
Centre for Mechanics of Biological Materials, University of Padova, Padova, Italy.|Department of Biomedical Sciences, University of Padova, Padova, Italy.
Chiara Giulia
CG
Fontanella
Department of Industrial Engineering, University of Padova, Padova, Italy.|Centre for Mechanics of Biological Materials, University of Padova, Padova, Italy.
Silvia
S
Todros
Centre for Mechanics of Biological Materials, University of Padova, Padova, Italy.|Department of Animal Medicine, Production and Health, University of Padova, Padova, Italy.
Giulia Maria
GM
De Benedictis
Urology Clinic, Verona Integrated University Hospital, Verona, Italy.
Maria Angela
MA
Cerruto
Urology Clinic, Verona Integrated University Hospital, Verona, Italy.
Walter
W
Artibani
D001696:Biomechanical Phenomena; D006801:Humans; D011474:Prosthesis Design; D015203:Reproducibility of Results; D016741:Urinary Sphincter, Artificial / Q000592:standards
Artificial sphincter; Finite element models; Non linear tissue mechanics; Urethral duct; Urological biomechanics