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Omouri A, Rapacchi S, Duclos J, Niddam R, Bellemare ME, Pirró N. 3D Observation of Pelvic Organs with Dynamic MRI Segmentation: A Bridge Toward Patient-Specific Models. Int Urogynecol J 2024; 35:1389-1397. [PMID: 38801556 DOI: 10.1007/s00192-024-05817-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 04/24/2024] [Indexed: 05/29/2024]
Abstract
INTRODUCTION AND HYPOTHESIS Female pelvic organ prolapses are common, but their treatment is challenging. Notably, diagnosis and understanding of these troubles remain incomplete. Tridimensional observations of displacement and deformation of the pelvic organs during a strain could support a better understanding and help to develop comprehensive tools for preoperative planning. METHODS The present feasibility study evaluates tridimensional dynamic MRI in 12 healthy volunteers. Tridimensional acquisitions were approximated using five intersecting slices, each recorded twice per second. MRI was performed during rest and strain, with intrarectal and intravaginal contrast gel. Subject-specific dynamic 3D models were built for each volunteer through segmentation. RESULTS For each volunteer, pelvic organs could be segmented in three dimensions with a rate of acquisition of two cycles per second on five slices, allowing for a fluid observation of displacements and deformations during strain. Manual segmentation of a full strain required 2 h and 33 min on average. The upper limit of the rectum and the pelvic floor were the most difficult structures to identify. This technique is limited by its time-consuming manual segmentation, which impedes its implantation for routine clinical use. This method must be tried in patients with pelvic organ prolapse. CONCLUSIONS This multi-planar acquisition technique applied during a dynamic MRI allows for observation of displacement and deformations of pelvic organs during a strain.
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Affiliation(s)
- Adel Omouri
- Aix-Marseille Univ-Service de Chirurgie Digestive et Oncologique-Hôpital de la Timone, 264, Rue Saint-Pierre, 13005, Marseille, France.
| | - Stanislas Rapacchi
- CNRS, CRMBM, Aix-Marseille Univ, 27 Boulevard Jean Moulin, 13005, Marseille, France
| | - Julie Duclos
- Aix-Marseille Univ-Service de Chirurgie Digestive et Oncologique-Hôpital de la Timone, 264, Rue Saint-Pierre, 13005, Marseille, France
| | - Raphaël Niddam
- Aix-Marseille Univ-Service de Chirurgie Digestive et Oncologique-Hôpital de la Timone, 264, Rue Saint-Pierre, 13005, Marseille, France
| | - Marc-Emmanuel Bellemare
- Laboratoire d'Informatique Et Systèmes, équipe I&M - UMR CNRS 7020, Aix-Marseille Université-CNRS, 52, Avenue Escadrille Normandie Niémen, 13397, Marseille Cedex 20, France
| | - Nicolas Pirró
- Aix-Marseille Univ-Service de Chirurgie Digestive et Oncologique-Hôpital de la Timone, 264, Rue Saint-Pierre, 13005, Marseille, France
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Lallemant M, Shimojyo AA, Mayeur O, Ramanah R, Rubod C, Kerbage Y, Cosson M. Mobility analysis of a posterior sacrospinous fixation using a finite element model of the pelvic system. PLoS One 2024; 19:e0299012. [PMID: 38512958 PMCID: PMC10956756 DOI: 10.1371/journal.pone.0299012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 02/04/2024] [Indexed: 03/23/2024] Open
Abstract
INTRODUCTION AND HYPOTHESIS In order to improve the knowledge POP physiopathology and POP repair, a generic biomechanical model of the female pelvic system has been developed. In the literature, no study has currently evaluated apical prolapse repair by posterior sacrospinous ligament fixation using a generic model nor a patient-specific model that personalize the management of POP and predict surgical outcomes based on the patient's pre-operative Magnetic Resonance Imaging. The aim of our study was to analyze the influence of a right and/or left sacrospinous ligament fixation and the distance between the anchorage area and the ischial spine on the pelvic organ mobility using a generic and a patient-specific Finite Element model (FEM) of the female pelvic system during posterior sacrospinous ligament fixation (SSF). METHODS Firstly, we used a generic 3D FEM of the female pelvic system previously made by our team that allowed us to simulate the mobility of the pelvic system. To create a patient-specific 3D FEM of the female pelvic system, we used a preoperative dynamic pelvic MRI of a 68 years old woman with a symptomatic stage III apical prolapse and cystocele. With these 2 models, a SSF was simulated. A right and/or left SSF and different distances between the anchorage area and the ischial spine (1 cm, 2 cm and 3 cm.) were compared. Outcomes measures were the pelvic organ displacement using the pubococcygeal line during maximal strain: Ba point for the most posterior and inferior aspect of the bladder base, C point the cervix's or the vaginal apex and Bp point for the anterior aspect of the anorectal junction. RESULTS Overall, pelvic organ mobility decreased regardless of surgical technique and model. According to the generic model, C point was displaced by 14.1 mm and 11.5 mm, Ba point by 12.7 mm, and 12 mm and Bp point by 10.6 mm and 9.9 mm after left and bilateral posterior SSF, respectively. C point was displaced by 15.4 mm and 11.6 mm and Ba point by 12.5 mm and 13.1mm when the suture on the sacrospinous ligament was performed at 1 cm and 3 cm from the ischial spine respectively (bilateral posterior SSF configuration). According to the patient-specific model, the displacement of Ba point could not be analyzed because of a significative and asymmetric organ displacement of the bladder. C point was displaced by 4.74 mm and 2.12 mm, and Bp point by 5.30 mm and 3.24 mm after left and bilateral posterior SSF respectively. C point was displaced by 4.80 mm and 4.85 mm and Bp point by 5.35 mm and 5.38 mm when the suture on the left sacrospinous ligament was performed at 1 cm and 3 cm from the ischial spine, respectively. CONCLUSION According to the generic model from our study, the apex appeared to be less mobile in bilateral SSF. The anchorage area on the sacrospinous ligament seems to have little effect on the pelvic organ mobilities. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT04551859.
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Affiliation(s)
- Marine Lallemant
- Service de Gynécologie Obstétrique, Pôle Mère-Femme, Centre Hospitalier Universitaire Jean Minjoz, Besançon, France
- Université Lille, CNRS, Centrale Lille, UMR 9013—LaMcube—Laboratoire de Mécanique, Multiphysique, Multiéchelle, F-59000, Lille, France
| | - Andres Arteaga Shimojyo
- Université Lille, CNRS, Centrale Lille, UMR 9013—LaMcube—Laboratoire de Mécanique, Multiphysique, Multiéchelle, F-59000, Lille, France
| | - Olivier Mayeur
- Université Lille, CNRS, Centrale Lille, UMR 9013—LaMcube—Laboratoire de Mécanique, Multiphysique, Multiéchelle, F-59000, Lille, France
| | - Rajeev Ramanah
- Service de Gynécologie Obstétrique, Pôle Mère-Femme, Centre Hospitalier Universitaire Jean Minjoz, Besançon, France
- Laboratoire de Nanomédecine, Imagerie et Thérapeutiques, INSERM E4 4662, Université de Franche-Comté, Besançon, France
| | - Chrystèle Rubod
- Université Lille, CNRS, Centrale Lille, UMR 9013—LaMcube—Laboratoire de Mécanique, Multiphysique, Multiéchelle, F-59000, Lille, France
- CHU Lille, Service de Chirurgie Gynécologique, F-59000, Lille, France
- Faculté de médecine, Université Lille Nord de France, F-59000, Lille, France
| | - Yohan Kerbage
- Université Lille, CNRS, Centrale Lille, UMR 9013—LaMcube—Laboratoire de Mécanique, Multiphysique, Multiéchelle, F-59000, Lille, France
- CHU Lille, Service de Chirurgie Gynécologique, F-59000, Lille, France
- Faculté de médecine, Université Lille Nord de France, F-59000, Lille, France
| | - Michel Cosson
- Université Lille, CNRS, Centrale Lille, UMR 9013—LaMcube—Laboratoire de Mécanique, Multiphysique, Multiéchelle, F-59000, Lille, France
- CHU Lille, Service de Chirurgie Gynécologique, F-59000, Lille, France
- Faculté de médecine, Université Lille Nord de France, F-59000, Lille, France
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Yang M, Chen C, Wang Z, Long J, Huang R, Qi W, Shi R. Finite element analysis of female pelvic organ prolapse mechanism: current landscape and future opportunities. Front Med (Lausanne) 2024; 11:1342645. [PMID: 38323034 PMCID: PMC10844411 DOI: 10.3389/fmed.2024.1342645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/05/2024] [Indexed: 02/08/2024] Open
Abstract
The prevalence of pelvic organ prolapse (POP) has been steadily increasing over the years, rendering it a pressing global health concern that significantly impacts women's physical and mental wellbeing as well as their overall quality of life. With the advancement of three-dimensional reconstruction and computer simulation techniques for pelvic floor structures, research on POP has progressively shifted toward a biomechanical focus. Finite element (FE) analysis is an established tool to analyze the biomechanics of complex systems. With the advancement of computer technology, an increasing number of researchers are now employing FE analysis to investigate the pathogenesis of POP in women. There is a considerable number of research on the female pelvic FE analysis and to date there has been less review of this technique. In this review article, we summarized the current research status of FE analysis in various types of POP diseases and provided a detailed explanation of the issues and future development in pelvic floor disorders. Currently, the application of FE analysis in POP is still in its exploratory stage and has inherent limitations. Through continuous development and optimization of various technologies, this technique can be employed with greater accuracy to depict the true functional state of the pelvic floor, thereby enhancing the supplementation of the POP mechanism from the perspective of computer biomechanics.
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Affiliation(s)
- Miyang Yang
- The First Clinical Medical College, The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Chujie Chen
- The First Clinical Medical College, The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Zhaochu Wang
- Department of Anorectal, The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Jiaye Long
- Department of Interventional Radiology, Inner Mongolia Forestry General Hospital, The Second Clinical Medical School of Inner Mongolia University for The Nationalities, Yakeshi, China
| | - Runyu Huang
- The First Clinical Medical College, The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Wan Qi
- Department of Radiology, The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Rong Shi
- Department of Anorectal, The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
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Xue X, Zheng Q, Gao Z, Shen J, Yao T. The influence of the combined impairments and apical mesh surgery on the biomechanical behavior of the pelvic floor system. Front Bioeng Biotechnol 2024; 11:1292407. [PMID: 38260732 PMCID: PMC10800848 DOI: 10.3389/fbioe.2023.1292407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/08/2023] [Indexed: 01/24/2024] Open
Abstract
Objective: The prolapse mechanism of multifactorial impairment of the female pelvic floor system and the mechanics of the pelvic floor after apical suspension surgery are not yet understood, so we developed biomechanical models of the pelvic floor for the normal physiological state (0°) and 90° pathological state. Methods: Under different types and levels of the impairments and uterosacral suspensions, the possible changes in the morphometric characteristics and the mechanical characteristics of suspension and support functions were simulated based on the biomechanical models of the pelvic floor. Results: After the combined impairments, the descending displacement of the pelvic floor cervix and the stress and displacement of the perineal body reached maximum values. After surgical mesh implantation, the stresses of the normal pelvic floor were concentrated on the uterine fundus, cervix, and top of the bladder and the stresses of the 90° pathological state pelvic floor were concentrated on the uterine fundus, uterine body, cervix, middle of the posterior vaginal wall, and bottom of the perineal body. Conclusion: After the combined impairments, the biomechanical support of the bladder and sacrococcyx in the anterior (0°) and 90° pathological state pelvic floor system is diminished, the anterior vaginal wall dislodges from the external vaginal opening, and the posterior vaginal wall forms "kneeling" profiles. The pelvic floor system may evolve with a tendency toward the cervical prolapse with anterior and posterior vaginal wall prolapse and eventually prolapse. After surgical mesh implantation, the cervical position can be better restored; however, the load of combined impairment of the pelvic floor is mainly borne by the surgical mesh suspension, the biomechanical support function of pelvic floor organs and sacrococcyx was not repaired by the physiological structure, and the results of uterosacral suspension alone may be poor.
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Affiliation(s)
- Xianglu Xue
- Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming, China
| | - Qiuyu Zheng
- Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming, China
| | - Zhenhua Gao
- The First Department of Urology, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Jihong Shen
- The First Department of Urology, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Tingqiang Yao
- Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming, China
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Tuttle T, McClintock D, Roccabianca S. Effects of swelling and anatomical location on the viscoelastic behavior of the porcine urinary bladder wall. J Mech Behav Biomed Mater 2023; 143:105926. [PMID: 37269604 DOI: 10.1016/j.jmbbm.2023.105926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 05/18/2023] [Accepted: 05/21/2023] [Indexed: 06/05/2023]
Abstract
The ability of the urinary bladder to perform its physiological function depends largely on its mechanical characteristics. Understanding the mechanics of this tissue is crucial to the development of accurate models of not just this specific organ, but of the pelvic floor overall. In this study, we tested porcine bladder to identify variations in the tissue's viscoelastic characteristics associated with anatomical locations and swelling. We investigated this relationship using a series of stress-relaxation experiments as well as a modified Maxwell-Wiechert model to aid in the interpretation of the experimental data. Our results highlight that tissue located near the neck of the bladder presents significantly different viscoelastic characteristics than the body of the organ. This supports what was previously observed and is a valuable contribution to the understanding of the location-specific properties of the bladder. We also tested the effect of swelling, revealing that the bladder's viscoelastic behavior is mostly independent of solution osmolarity in hypoosmotic solutions, but the use of a hyperosmotic solution can significantly affect its behavior. This is significant, since several urinary tract pathologies can lead to chronic inflammation and disrupt the urothelial barrier causing increased urothelial permeability, thus subjecting the bladder wall to non-physiologic osmotic challenge.
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Affiliation(s)
- Tyler Tuttle
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, 48823, USA
| | - Dillon McClintock
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, 48823, USA
| | - Sara Roccabianca
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, 48823, USA.
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6
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Doherty S, Landis B, Owings TM, Erdemir A. Template models for simulation of surface manipulation of musculoskeletal extremities. PLoS One 2022; 17:e0272051. [PMID: 35969593 PMCID: PMC9377586 DOI: 10.1371/journal.pone.0272051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 07/12/2022] [Indexed: 11/18/2022] Open
Abstract
Capturing the surface mechanics of musculoskeletal extremities would enhance the realism of life-like mechanics imposed on the limbs within surgical simulations haptics. Other fields that rely on surface manipulation, such as garment or prosthetic design, would also benefit from characterization of tissue surface mechanics. Eight homogeneous tissue models were developed for the upper and lower legs and arms of two donors. Ultrasound indentation data was used to drive an inverse finite element analysis for individualized determination of region-specific material coefficients for the lumped tissue. A novel calibration strategy was implemented by using a ratio based adjustment of tissue properties from linear regression of model predicted and experimental responses. This strategy reduced requirement of simulations to an average of under four iterations. These free and open-source specimen-specific models can serve as templates for simulations focused on mechanical manipulations of limb surfaces.
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Affiliation(s)
- Sean Doherty
- Department of Biomedical Engineering and Computational Biomodeling (CoBi) Core, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Ben Landis
- Department of Biomedical Engineering and Computational Biomodeling (CoBi) Core, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Tammy M. Owings
- Department of Biomedical Engineering and Computational Biomodeling (CoBi) Core, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Ahmet Erdemir
- Department of Biomedical Engineering and Computational Biomodeling (CoBi) Core, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
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7
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Silva METD, Bessa JNM, Rynkevic R, Parente MPL, Saraiva MTDQECM, Natal Jorge RM, Fernandes AA. Simulation of vaginal uterosacral ligament suspension damage, mimicking a mesh-augmented apical prolapse repair. Proc Inst Mech Eng H 2022; 236:9544119221074567. [PMID: 35088624 DOI: 10.1177/09544119221074567] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Synthetic implants were used for repair of anterior compartment prolapses, which can be caused by direct trauma resulting in damaged pelvic structures. The mechanical properties of these implants may cause complications, namely erosion of the mesh through the vagina. In this study, we evaluated, by modeling, the behavior of implants, during Valsalva maneuver, used to replace damaged uterosacral ligaments (USLs), mimicking a sacrocolpopexy repair. For this purpose, two synthetic implants (A®, for prolapse repair and B®, for Hernia repair) were uniaxially tested, and the mechanical properties obtained were incorporated in the computational models of the implants. The computational model for the implant was incorporated into the model of the female pelvic cavity, in order to mimic the USLs after its total rupture and with 90% and 50% impairment. The total rupture and impairments of the USLs, caused a variation of the supero-inferior displacement and displacement magnitude of the vagina, with higher values for the total rupture. With total rupture of the USLs, when compared to healthy USLs, supero-inferior displacement and displacement magnitude of the vagina increased by 4.98 mm (7.69 mm vs 12.67 mm) and 6.62 mm (9.38 mm vs 16.00 mm), respectively. After implantation (A® and B®) a reduction of the supero-inferior displacements of the anterior vaginal wall occurred, to values found in the case of the model without any impairment or rupture of the ligaments. The simulation was able to mimic the biomechanical response of the USLs, in response to different implants stiffnesses, which can be used in the development of novel meshes.
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Affiliation(s)
| | | | - Rita Rynkevic
- LAETA, INEGI, Faculty of Engineering, University of Porto, Porto, Portugal
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8
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Diallo MN, Mayeur O, Lecomte-Grosbras P, Patrouix L, Witz JF, Lesaffre F, Rubod C, Cosson M, Brieu M. Simulation of the mobility of the pelvic system: influence of fascia between organs. Comput Methods Biomech Biomed Engin 2021; 25:1073-1087. [PMID: 34783611 DOI: 10.1080/10255842.2021.2001460] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The mobility of pelvic organs is the result of an equilibrium called Pelvic Static characterizing the balance between the properties and geometries of organs, suspensions and support system. Any imbalance in this complex system can cause of pelvic static disorder. Genital prolapse is a common hypermobility pathology which is complex, multi factorial and its surgical management has high rate of complications. The use of 3 D numerical models and simulation enables the role of the various suspension structures to be objectively studied and quantified. Fascias are connective tissues located between organs. Although their role are described as important in various descriptions of pelvic statics, their influence and role has never been quantitatively objectified. This article presents a refine Finite Element (FE) model for a better understanding of biomechanical contribution of inter-organ fascia. The model is built from MRI images of a young volunteer, the mechanical properties derived from literature data to take into account the age of the patient and new experimental results have enabled an order of magnitude of the mechanical properties of the fascias to be defined. The FE results allows to quantify the biomechanical role of the fascia on pelvic mobility quantified by an analysis of dynamic MRI images and a local mapping of the gap between calculated and measured displacements. This improved numerical model integrating the fascias makes it possible to describe pelvic mobilities with a gap of 1 mm between numerical simulations and measurements, whereas without taking them into account this gap locally reaches 20 mm.
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Affiliation(s)
- Mouhamadou Nassirou Diallo
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France
| | - Olivier Mayeur
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France
| | - Pauline Lecomte-Grosbras
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France
| | - Laurent Patrouix
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France
| | - Jean François Witz
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France
| | - François Lesaffre
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France
| | - Chrystle Rubod
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France.,Service de chirurgie gynécologique - CHU Lille, Lille, France
| | - Michel Cosson
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France.,Service de chirurgie gynécologique - CHU Lille, Lille, France
| | - Mathias Brieu
- CNRS, Centrale Lille, UMR 9013 - LaMcube - Laboratoire de Mécanique, Multiphysique, Multiéchelle, University of Lille, Lille, France.,Department of Mechanical Engineering, College Engineering, Computer Science and Technology, California State University, Los Angeles, Long Angeles, CA, USA
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9
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Clark-Patterson GL, Roy S, Desrosiers L, Knoepp LR, Sen A, Miller KS. Role of fibulin-5 insufficiency and prolapse progression on murine vaginal biomechanical function. Sci Rep 2021; 11:20956. [PMID: 34697337 PMCID: PMC8546087 DOI: 10.1038/s41598-021-00351-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/31/2021] [Indexed: 02/04/2023] Open
Abstract
The vagina plays a critical role in supporting the pelvic organs and loss of support leads to pelvic organ prolapse. It is unknown what microstructural changes influence prolapse progression nor how decreased elastic fibers contributes to vaginal remodeling and smooth muscle contractility. The objective for this study was to evaluate the effect of fibulin-5 haploinsufficiency, and deficiency with progressive prolapse on the biaxial contractile and biomechanical function of the murine vagina. Vaginas from wildtype (n = 13), haploinsufficient (n = 13), and deficient mice with grade 1 (n = 9) and grade 2 or 3 (n = 9) prolapse were explanted for biaxial contractile and biomechanical testing. Multiaxial histology (n = 3/group) evaluated elastic and collagen fiber microstructure. Western blotting quantified protein expression (n = 6/group). A one-way ANOVA or Kruskal-Wallis test evaluated statistical significance. Pearson's or Spearman's test determined correlations with prolapse grade. Axial contractility decreased with fibulin-5 deficiency and POP (p < 0.001), negatively correlated with prolapse grade (ρ = - 0.80; p < 0.001), and positively correlated with muscularis elastin area fraction (ρ = - 0.78; p = 0.004). Circumferential (ρ = 0.71; p < 0.001) and axial (ρ = 0.69; p < 0.001) vaginal wall stresses positively correlated with prolapse grade. These findings demonstrated that fibulin-5 deficiency and prolapse progression decreased vaginal contractility and increased vaginal wall stress. Future work is needed to better understand the processes that contribute to prolapse progression in order to guide diagnostic, preventative, and treatment strategies.
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Affiliation(s)
| | - Sambit Roy
- Department of Animal Sciences, Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, 48824, USA
| | - Laurephile Desrosiers
- Department of Female Pelvic Medicine and Reconstructive Surgery, University of Queensland Ochsner Clinical School, New Orleans, 70121, USA
| | - Leise R Knoepp
- Department of Female Pelvic Medicine and Reconstructive Surgery, University of Queensland Ochsner Clinical School, New Orleans, 70121, USA
| | - Aritro Sen
- Department of Animal Sciences, Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, 48824, USA
| | - Kristin S Miller
- Department of Biomedical Engineering, Tulane University, New Orleans, 70118, USA.
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10
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Biomechanical trade-offs in the pelvic floor constrain the evolution of the human birth canal. Proc Natl Acad Sci U S A 2021; 118:2022159118. [PMID: 33853947 DOI: 10.1073/pnas.2022159118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Compared with most other primates, humans are characterized by a tight fit between the maternal birth canal and the fetal head, leading to a relatively high risk of neonatal and maternal mortality and morbidities. Obstetric selection is thought to favor a spacious birth canal, whereas the source for opposing selection is frequently assumed to relate to bipedal locomotion. Another, yet underinvestigated, hypothesis is that a more expansive birth canal suspends the soft tissue of the pelvic floor across a larger area, which is disadvantageous for continence and support of the weight of the inner organs and fetus. To test this "pelvic floor hypothesis," we generated a finite element model of the human female pelvic floor and varied its radial size and thickness while keeping all else constant. This allowed us to study the effect of pelvic geometry on pelvic floor deflection (i.e., the amount of bending from the original position) and tissue stresses and stretches. Deflection grew disproportionately fast with increasing radial size, and stresses and stretches also increased. By contrast, an increase in thickness increased pelvic floor stiffness (i.e., the resistance to deformation), which reduced deflection but was unable to fully compensate for the effect of increasing radial size. Moreover, larger thicknesses increase the intra-abdominal pressure necessary for childbirth. Our results support the pelvic floor hypothesis and evince functional trade-offs affecting not only the size of the birth canal but also the thickness and stiffness of the pelvic floor.
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11
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Guachi R, Bini F, Bici M, Campana F, Marinozzi F, Guachi L. Finite element analysis in colorectal surgery: non-linear effects induced by material model and geometry. COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING: IMAGING & VISUALIZATION 2019. [DOI: 10.1080/21681163.2019.1679669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Robinson Guachi
- Department of Mechatronics, Universidad Internacional del Ecuador, Quito, Ecuador
- Dipartimento di ingegneria Meccanica e Aerospaziale, Universita degli Studi di Roma La Sapienza, Roma, Italy
| | - Fabiano Bini
- Dipartimento di ingegneria Meccanica e Aerospaziale, Universita degli Studi di Roma La Sapienza, Roma, Italy
| | - Michele Bici
- Dipartimento di ingegneria Meccanica e Aerospaziale, Universita degli Studi di Roma La Sapienza, Roma, Italy
| | - Francesca Campana
- Dipartimento di ingegneria Meccanica e Aerospaziale, Universita degli Studi di Roma La Sapienza, Roma, Italy
| | - Franco Marinozzi
- Dipartimento di ingegneria Meccanica e Aerospaziale, Universita degli Studi di Roma La Sapienza, Roma, Italy
| | - Lorena Guachi
- Mathematical and Computational Sciences, Yachay University, Urcuquí, Ecuador
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Gordon MT, DeLancey JOL, Renfroe A, Battles A, Chen L. Development of anatomically based customizable three-dimensional finite-element model of pelvic floor support system: POP-SIM1.0. Interface Focus 2019; 9:20190022. [PMID: 31263537 PMCID: PMC6597525 DOI: 10.1098/rsfs.2019.0022] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2019] [Indexed: 12/24/2022] Open
Abstract
To develop an anatomically based customizable finite-element (FE) model of the pelvic floor support system to simulate pelvic organ prolapse (POP): POP-SIM1.0. This new simulation platform allows for the construction of an array of models that objectively represent the key anatomical and functional variation in women with and without prolapse to test pathomechanism hypotheses of the prolapse formation. POP-SIM1.0 consists of anatomically based FE models and a suite of Python-based tools developed to rapidly construct FE models by customizing the base model with desired structural parameters. Each model consists of anatomical structures from three support subsystems which can be customized based on magnetic resonance image measurements in women with and without prolapse. The customizable structural parameters include presence of levator ani (LA) avulsion, hiatus size, anterior vaginal wall dimension, attachment fascia length and apical location in addition to the tissue material properties and intra-abdominal pressure loading. After customization, the FE model was loaded with increasing intra-abdominal pressure (0-100 cmH2O) and solved using ABAQUS explicit solver. We were able to rapidly construct anatomically based FE models with specific structural geometry which reflects the morphology changes often observed in women with prolapse. At maximum loading, simulated structural deformations have similar anatomical characteristics to those observed during clinical exams and stress magnetic resonance images. Simulation results showed the presence of LA muscle avulsion negatively impacts the pelvic floor support. The normal model with intact muscle had the smallest exposed vaginal length of 11 mm, while the bilateral avulsion produced the largest exposed vaginal length at 24 mm. The unilateral avulsion model had an exposed vaginal length of 18 mm and also demonstrated a tipped perineal body similar to that seen in clinical observation. Increasing the hiatus size, vaginal wall length and fascia length also resulted in worse pelvic floor support, increasing the exposed vaginal length from 18 mm in the base model to 33 mm, 54 mm and 23.5 mm, respectively. The developed POP-SIM1.0 can simulate the anatomical structure changes often observed in women with prolapse. Preliminary results showed that the presence of LA avulsion, enlarged hiatus, longer vaginal wall and fascia length can result in larger prolapse at simulated maximum Valsalva.
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Affiliation(s)
- Mark T. Gordon
- Department of Bioengineering, California Baptist University, Riverside, CA, USA
| | - John O. L. DeLancey
- Department of Obstetrics and Gynecology, Pelvic Floor Research Group, University of Michigan, Ann Arbor, MI, USA
| | - Aaron Renfroe
- Department of Bioengineering, California Baptist University, Riverside, CA, USA
| | - Andrew Battles
- Department of Bioengineering, California Baptist University, Riverside, CA, USA
| | - Luyun Chen
- Department of Obstetrics and Gynecology, Pelvic Floor Research Group, University of Michigan, Ann Arbor, MI, USA
- Department of Biomedical Engineering, Pelvic Floor Research Group, University of Michigan, Ann Arbor, MI, USA
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Guachi R, Bini F, Bici M, Campana F, Marinozzi F. Finite Element Model Set-up of Colorectal Tissue for Analyzing Surgical Scenarios. VIPIMAGE 2017 2018. [DOI: 10.1007/978-3-319-68195-5_65] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Jean Dit Gautier E, Mayeur O, Lepage J, Brieu M, Cosson M, Rubod C. Pregnancy impact on uterosacral ligament and pelvic muscles using a 3D numerical and finite element model: preliminary results. Int Urogynecol J 2017; 29:425-430. [DOI: 10.1007/s00192-017-3520-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 11/08/2017] [Indexed: 12/28/2022]
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Abstract
PURPOSE OF REVIEW The pelvic floor is a complex assembly of connective tissues and striated muscles that simultaneously counteracts gravitational forces, inertial forces, and intra-abdominal pressures while maintaining the position of the pelvic organs. In 30% of women, injury or failure of the pelvic floor results in pelvic organ prolapse. Surgical treatments have high recurrence rates, due, in part, to a limited understanding of physiologic loading conditions. It is critical to apply biomechanics to help elucidate how altered loading conditions of the pelvis contribute to the development of pelvic organ prolapse and to define surgeries to restore normal support. RECENT FINDINGS Evidence suggests the ewe is a potential animal model for studying vaginal properties and that uterosacral and cardinal ligaments experience significant creep, which may be affecting surgical outcomes. A new method of measuring ligament displacements in vivo was developed, and finite element models that simulate urethral support, pelvic floor dynamics, and the impact of episiotomies on the pelvic floor were studied. SUMMARY The current review highlights some contributions over the past year, including mechanical testing and the creation of models, which are used to understand pelvic floor changes with loading and the impact of surgical procedures, to illustrate how biomechanics is being utilized.
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Affiliation(s)
- Deanna C. Easley
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA
| | | | - Pamela A. Moalli
- Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of Pittsburgh, Pittsburgh, PA
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Dias N, Peng Y, Khavari R, Nakib NA, Sweet RM, Timm GW, Erdman AG, Boone TB, Zhang Y. Pelvic floor dynamics during high-impact athletic activities: A computational modeling study. Clin Biomech (Bristol, Avon) 2017; 41:20-27. [PMID: 27886590 PMCID: PMC5519824 DOI: 10.1016/j.clinbiomech.2016.11.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 11/09/2016] [Accepted: 11/15/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Stress urinary incontinence is a significant problem in young female athletes, but the pathophysiology remains unclear because of the limited knowledge of the pelvic floor support function and limited capability of currently available assessment tools. The aim of our study is to develop an advanced computer modeling tool to better understand the dynamics of the internal pelvic floor during highly transient athletic activities. METHODS Apelvic model was developed based on high-resolution MRI scans of a healthy nulliparous young female. A jump-landing process was simulated using realistic boundary conditions captured from jumping experiments. Hypothesized alterations of the function of pelvic floor muscles were simulated by weakening or strengthening the levator ani muscle stiffness at different levels. Intra-abdominal pressures and corresponding deformations of pelvic floor structures were monitored at different levels of weakness or enhancement. FINDINGS Results show that pelvic floor deformations generated during a jump-landing process differed greatly from those seen in a Valsalva maneuver which is commonly used for diagnosis in clinic. The urethral mobility was only slightly influenced by the alterations of the levator ani muscle stiffness. Implications for risk factors and treatment strategies were also discussed. INTERPRETATION Results suggest that clinical diagnosis should make allowances for observed differences in pelvic floor deformations between a Valsalva maneuver and a jump-landing process to ensure accuracy. Urethral hypermobility may be a less contributing factor than the intrinsic sphincteric closure system to the incontinence of young female athletes.
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Affiliation(s)
- Nicholas Dias
- Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA.
| | - Yun Peng
- Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA.
| | - Rose Khavari
- Department of Urology, Houston Methodist Hospital and Research Institute, 6565 Fannin St, Suite 2100, Houston, TX 77030-2703, USA.
| | - Nissrine A Nakib
- Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA.
| | - Robert M Sweet
- Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA.
| | - Gerald W Timm
- Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA.
| | - Arthur G Erdman
- Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN 55455-0341, USA.
| | - Timothy B Boone
- Department of Urology, Houston Methodist Hospital and Research Institute, 6565 Fannin St, Suite 2100, Houston, TX 77030-2703, USA.
| | - Yingchun Zhang
- Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA.
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Lamblin G, Mayeur O, Giraudet G, Jean Dit Gautier E, Chene G, Brieu M, Rubod C, Cosson M. Pathophysiological aspects of cystocele with a 3D finite elements model. Arch Gynecol Obstet 2016; 294:983-989. [PMID: 27402504 DOI: 10.1007/s00404-016-4150-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/06/2016] [Indexed: 01/01/2023]
Abstract
PURPOSES The objective of this study is to design a 3D biomechanical model of the female pelvic system to assess pelvic organ suspension theories and understand cystocele mechanisms. METHODS A finite elements (FE) model was constructed to calculate the impact of suspension structure geometry on cystocele. The sample was a geometric model of a control patient's pelvic organs. The method used geometric reconstruction, implemented by the biomechanical properties of each anatomic structure. Various geometric configurations were simulated on the FE method to analyse the role of each structure and compare the two main anatomic theories. RESULTS The main outcome measure was a 3D biomechanical model of the female pelvic system. The various configurations of bladder displacement simulated mechanisms underlying medial, lateral and apical cystocele. FE simulation revealed that pubocervical fascia is the most influential structure in the onset of median cystocele (essentially after 40 % impairment). Lateral cystocele showed a stronger influence of arcus tendineus fasciae pelvis (ATFP) on vaginal wall displacement under short ATFP lengthening. In apical cystocele, the uterosacral ligament showed greater influence than the cardinal ligament. Suspension system elongation increased displacement by 25 % in each type of cystocele. CONCLUSIONS A 3D digital model enabled simulations of anatomic structures underlying cystocele to better understand cystocele pathophysiology. The model could be used to predict cystocele surgery results and personalising technique by preoperative simulation.
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Affiliation(s)
- Géry Lamblin
- Department of Urogynecology, HFME, HCL, Femme Mère Enfant University Hospital, 59 Boulevard Pinel, Lyon-Bron, 69677, Bron, France.
- University of Claude Bernard Lyon 1, Villeurbanne, France.
- University of Medicine Henri Warembourg, Lille University, Villeneuve-d'Ascq, France.
| | - Olivier Mayeur
- FRE 3723-LML-Laboratoire de Mécanique de Lille, Univ. Lille, 59000, Lille, France
- Centrale Lille, Cité Scientifique CS 20048, 59000, Lille, France
| | - Géraldine Giraudet
- University of Medicine Henri Warembourg, Lille University, Villeneuve-d'Ascq, France
- Department of Urogynecology, Jeanne de Flandre Hospital, Lille, France
- Lille 2 University, Lille, France
| | - Estelle Jean Dit Gautier
- University of Medicine Henri Warembourg, Lille University, Villeneuve-d'Ascq, France
- Department of Urogynecology, Jeanne de Flandre Hospital, Lille, France
- Lille 2 University, Lille, France
| | - Gautier Chene
- Department of Urogynecology, HFME, HCL, Femme Mère Enfant University Hospital, 59 Boulevard Pinel, Lyon-Bron, 69677, Bron, France
- University of Claude Bernard Lyon 1, Villeurbanne, France
| | - Mathias Brieu
- FRE 3723-LML-Laboratoire de Mécanique de Lille, Univ. Lille, 59000, Lille, France
- Centrale Lille, Cité Scientifique CS 20048, 59000, Lille, France
| | - Chrystèle Rubod
- University of Medicine Henri Warembourg, Lille University, Villeneuve-d'Ascq, France
- FRE 3723-LML-Laboratoire de Mécanique de Lille, Univ. Lille, 59000, Lille, France
- Department of Urogynecology, Jeanne de Flandre Hospital, Lille, France
- Lille 2 University, Lille, France
| | - Michel Cosson
- University of Medicine Henri Warembourg, Lille University, Villeneuve-d'Ascq, France
- FRE 3723-LML-Laboratoire de Mécanique de Lille, Univ. Lille, 59000, Lille, France
- Department of Urogynecology, Jeanne de Flandre Hospital, Lille, France
- Lille 2 University, Lille, France
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Mobility and stress analysis of different surgical simulations during a sacral colpopexy, using a finite element model of the pelvic system. Int Urogynecol J 2016; 27:951-7. [PMID: 26755057 DOI: 10.1007/s00192-015-2917-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/02/2015] [Indexed: 10/22/2022]
Abstract
INTRODUCTION AND HYPOTHESIS We aim to analyze the combined influence of the size of the mesh, the number of sutures, the combined use of an anterior and posterior mesh, and the tension applied to the promontory, on the mobility of the pelvic organs and on the sutures, using a Finite Element (FE) model of the female pelvic system during abdominal sacral colpopexy. METHODS We used a FE model of the female pelvic system, which allowed us to simulate the mobility of the pelvic system and to evaluate problems related to female prolapse. The meshes were added to the geometrical model and then transferred to computing software. This analysis allowed us to compare the stress and mobility during a thrust effort in different situations. RESULTS The bigger the mesh, the less mobility of both anterior and posterior organs there would be. This is accompanied by an increase in stress at the suture level. The combination of a posterior mesh with an anterior one decreases mobility and stress at the suture level. There is a particularly relevant stressing zone on the suture at the cervix. The increase in the number of sutures induces a decrease in the tension applied at each suture zone and has no impact on organ mobility. CONCLUSION Our model enables us to simulate and analyze an infinite number of surgical hypotheses. Even if these results are not validated at a clinical level, we can observe the importance of the association of both an anterior and a posterior mesh or the number of sutures.
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