Fernanda Pipitone1,2, Carolyn W Swenson3,4, John O L DeLancey3,4, Luyun Chen4,5. 1. Pelvic Floor Research Group, University of Michigan, 1500 E Medical Center Dr, Ann Arbor, MI, 48109, USA. fernanda.pipitone@gmail.com. 2. Hospital das Clínicas da FMUSP, University of São Paulo, São Paulo, Brazil. fernanda.pipitone@gmail.com. 3. Pelvic Floor Research Group, University of Michigan, 1500 E Medical Center Dr, Ann Arbor, MI, 48109, USA. 4. Department of Obstetrics and Gynecology, Michigan Medicine, Ann Arbor, MI, USA. 5. Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
Abstract
INTRODUCTION AND HYPOTHESIS: We aimed to develop and validate a new MRI-based perineal membrane reconstruction and morphological measurement technique, and test its feasibility on nulliparous and parous women to determine the effects of pregnancy and childbirth on the perineal membrane. METHODS: The perineal membrane was traced on high-resolution MRI using 3D Slicer® and analyses performed using Rhinoceros 6.0 SR23®. Validation was done by comparing MRI-based perineal membrane reconstruction to dissection measurements in a cadaver. Feasibility of reconstruction was assessed in the following three groups: nulliparous (NP), primiparous women who underwent cesarean delivery (CD), and primiparous women with vaginal delivery (VD). The following parameters were measured: (1) swinging door angle, (2) bony and (3) soft tissue attachment lengths, (4) separation at perineal body level, (5) surface area, and (6) hiatal area. ANOVA and post-hoc comparisons were performed, and the effect sizes (d) were reported. RESULTS: Model reconstruction was similar to cadaver dissection findings. Morphological measurements were feasible in all women (NP, n = 10; CS, n = 6; VD, n = 19). Swinging door angle was 13o greater in CD (p = 0.03; d = 1.15) and 16o greater in VD (p < 0.001; d = 1.41) compared to NP. VD showed 13% larger separation at the perineal body than NP (p = 0.097, d = 0.84) and 23% larger hiatal area than CD (p = 0.14, d = 0.94). CONCLUSION: This novel and anatomically validated MRI-based perineal membrane reconstruction technique is feasible. Preliminary findings show that pregnancy and childbirth both influence perineal membrane morphology with VD being associated with the largest swinging door angle and perineal body separation.
INTRODUCTION AND HYPOTHESIS: We aimed to develop and validate a new MRI-based perineal membrane reconstruction and morphological measurement technique, and test its feasibility on nulliparous and parous women to determine the effects of pregnancy and childbirth on the perineal membrane. METHODS: The perineal membrane was traced on high-resolution MRI using 3D Slicer® and analyses performed using Rhinoceros 6.0 SR23®. Validation was done by comparing MRI-based perineal membrane reconstruction to dissection measurements in a cadaver. Feasibility of reconstruction was assessed in the following three groups: nulliparous (NP), primiparous women who underwent cesarean delivery (CD), and primiparous women with vaginal delivery (VD). The following parameters were measured: (1) swinging door angle, (2) bony and (3) soft tissue attachment lengths, (4) separation at perineal body level, (5) surface area, and (6) hiatal area. ANOVA and post-hoc comparisons were performed, and the effect sizes (d) were reported. RESULTS: Model reconstruction was similar to cadaver dissection findings. Morphological measurements were feasible in all women (NP, n = 10; CS, n = 6; VD, n = 19). Swinging door angle was 13o greater in CD (p = 0.03; d = 1.15) and 16o greater in VD (p < 0.001; d = 1.41) compared to NP. VD showed 13% larger separation at the perineal body than NP (p = 0.097, d = 0.84) and 23% larger hiatal area than CD (p = 0.14, d = 0.94). CONCLUSION: This novel and anatomically validated MRI-based perineal membrane reconstruction technique is feasible. Preliminary findings show that pregnancy and childbirth both influence perineal membrane morphology with VD being associated with the largest swinging door angle and perineal body separation.
Authors: Victoria L Handa; Jennifer Roem; Joan L Blomquist; Hans Peter Dietz; Alvaro Muñoz Journal: Am J Obstet Gynecol Date: 2019-03-15 Impact factor: 8.661
Authors: Catherine J Brandon; Christina Lewicky-Gaupp; Kindra A Larson; John O L Delancey Journal: Am J Obstet Gynecol Date: 2009-05 Impact factor: 8.661
Authors: Wenjin Cheng; Emily English; Whitney Horner; Carolyn W Swenson; Luyun Chen; Fernanda Pipitone; James A Ashton-Miller; John O L DeLancey Journal: Int Urogynecol J Date: 2022-09-21 Impact factor: 1.932