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Schmidt P, Swenson CW, DeLancey JO, Chen L. Postpartum Changes in Levator Plate Shape and Genital Hiatus Size After Vaginal Delivery. Int Urogynecol J 2024; 35:1413-1420. [PMID: 38811410 DOI: 10.1007/s00192-024-05813-4] [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: 02/28/2024] [Accepted: 04/18/2024] [Indexed: 05/31/2024]
Abstract
INTRODUCTION AND HYPOTHESIS Vaginal delivery is a risk factor for pelvic organ prolapse. We sought to quantify changes in level III pelvic support measurements at 7 weeks and 8 months following vaginal delivery. METHODS This secondary analysis included primiparous women who underwent pelvic MRI and clinical examinations at 7 weeks and 8 months after vaginal delivery. Demographics and obstetrical data were abstracted. Mid-sagittal resting MRIs were used to perform level III measurements including urogenital hiatus (UGH), levator hiatus (LH), and mid-sagittal levator area (LA), and to trace the levator plate (LP). Using principal component analysis, 7-week and 8-month principal component scores (PC1s) and MRI measurements were compared using paired t test. If the PC1 score change from 7 weeks to 8 months was > 0, women were considered to have a more dorsally oriented LP shape. RESULTS Of 76 participants, POP-Q values did not significantly differ between 7 weeks and 8 months, but MRI measurements improved (UGH: 3.9 ± 0.8 vs 3.5 ± 0.8, p < 0.001; LH: 5.4 ± 0.8 vs 5.2 ± 0.8, p = 0.01; LA: 18.0 ± 6.0 vs 15.2 ± 6.5, p < 0.001). Approximately 30% (22 out of 76) had a more dorsally oriented LP shape and larger level III measurements at 8 months than women with a more ventrally oriented LP shape (LA: 86.4% vs 1.9%, p < 0.001; LH: 16% vs 12%, p < 0.001; UGH: 59.1% vs 3.7%, p < 0.001). CONCLUSIONS After vaginal delivery, most women had "recovery" of level III support-defined by smaller UGH, LH, and LA measurements-and a more ventrally oriented LP shape. However, nearly 30% had larger level III measurements and a more dorsally oriented LP shape, indicating "impaired recovery" of support.
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Affiliation(s)
- Payton Schmidt
- Department of Obstetrics and Gynecology, University of Michigan, 1500 E. Medical Center Drive, Ann Arbor, MI, 48109, USA.
| | - Carolyn W Swenson
- Department of Obstetrics and Gynecology, University of Utah, Salt Lake City, UT, USA
| | - John O DeLancey
- Department of Obstetrics and Gynecology, University of Michigan, 1500 E. Medical Center Drive, Ann Arbor, MI, 48109, USA
| | - Luyun Chen
- Department of Obstetrics and Gynecology, University of Michigan, 1500 E. Medical Center Drive, Ann Arbor, MI, 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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Duarte Thibault M, Chen L, Huebner M, DeLancey JO, Swenson CW. A comparison of MRI-based pelvic floor support measures between young and old women with prolapse. Int Urogynecol J 2023; 34:2081-2088. [PMID: 36971829 PMCID: PMC10566251 DOI: 10.1007/s00192-023-05505-5] [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: 12/02/2022] [Accepted: 02/14/2023] [Indexed: 03/29/2023]
Abstract
INTRODUCTION AND HYPOTHESIS We sought to 1) test the hypothesis that young women (≤45 years) with pelvic organ prolapse have a higher prevalence of major levator ani muscle (LAM) defects than old women (≥70 years) with prolapse and 2) compare level II/III measurements between young and old women with prolapse and age-matched controls to evaluate age-related mechanistic differences in the disease process. METHODS A secondary analysis examined four groups of parous women: young prolapse (YPOP, n = 17); old prolapse (OPOP, n = 17); young controls (YC, n = 15); old controls, (OC, n = 13). Prolapse was defined as any compartment at or beyond the hymen with vaginal bulge symptoms. Genital hiatus (GH) was measured on clinical exam. Major LAM defects and level II/III measurements (UGH: urogenital hiatus, LA: levator area, and apex location) were assessed on MRI at rest and strain, and the difference (Δ) between measurements calculated. Principal component analysis was used to evaluate levator plate (LP) shape. RESULTS Major LAM defects occurred in 42% of YPOP and 47% of OPOP (p > .99). GHrest was 1.5 cm larger in OPOP versus YPOP (p < .001) and 2 cm larger in OPOP versus OC (p < .001). Regardless of prolapse status, LArest and UGHrest on MRI increased with age. YPOP had larger ΔLA (p = .04), ΔUGH (p = .03), and Δapex than OPOP (p = .01). Resting LP shape was more dorsally oriented in OPOP versus YPOP (p = .02) and OC versus YC (p = .004). CONCLUSIONS Prolapse in young women cannot be solely explained by a higher LAM defect prevalence. GH size and other measures of level II/III pelvic support worsen with age regardless of prolapse status.
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Affiliation(s)
- Mary Duarte Thibault
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA.
- Department of Obstetrics and Gynecology, Baylor College of Medicine, 6651 Main Street, Houston, TX, 77030, USA.
| | - Luyun Chen
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Markus Huebner
- Department of Obstetrics and Gynecology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Tuebingen, Tuebingen, Germany
| | - John O DeLancey
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA
| | - Carolyn W Swenson
- Division of Urogynecology, Department of Obstetrics & Gynecology, University of Utah, Salt Lake City, UT, USA
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Zhou M, Shui W, Bai W, Wu X, Ying T. Ultrasonographic study of female perineal body and its supportive function on pelvic floor. Front Med (Lausanne) 2023; 10:1176360. [PMID: 37564038 PMCID: PMC10410282 DOI: 10.3389/fmed.2023.1176360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/12/2023] [Indexed: 08/12/2023] Open
Abstract
Objectives The study aimed to observe, measure the size and elastic value of perineal body (PB) and assess its association with levator hiatus. Methods Datasets were acquired in 45 nulliparous, 66 POP women and 70 postpartum women using ultrasound. The PB was measured in depth, height, and Young's modulus. The datasets were compared to assess whether there are some differences in the morphology, dimension and elastography modulus of PB among women. Pearson correlation analysis was used to evaluate the association between the morphology measurements (ΔValsalva-rest[v-r]), tissue mechanical properties (ΔValsalva-rest[v-r]) of the PB and levator hiatus area (ΔValsalva-rest[v-r]) to preliminarily explore whether PB can influence levator hiatus. Results Four representative manifestations of PB were presented in our study. Nulliparous women had smaller diameters and bigger Young's modulus while postpartum women had bigger diameters and smaller Young's modulus. POP and postpartum women had bigger levator hiatal distensibility and PB extensibility. There was no statistical association between PB measurements and levator hiatal area. Conclusion It is feasible to observe the morphology of PB and assess the dimension and elastography modulus by high-frequency ultrasound. The manifestations and measurements of PB are influenced by parity and long-term increased abdominal pressure. Our study preliminarily shows that PB has little effect on levator hiatus area.
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Affiliation(s)
| | | | | | | | - Tao Ying
- Department of Ultrasound in Medicine, Shanghai Institute of Ultrasound in Medicine, Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Liu X, Rong Q, Liu Y, Wang J, Xie B, Ren S. Relationship between high intra-abdominal pressure and compliance of the pelvic floor support system in women without pelvic organ prolapse: A finite element analysis. Front Med (Lausanne) 2022; 9:820016. [PMID: 36004379 PMCID: PMC9393536 DOI: 10.3389/fmed.2022.820016] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Previous studies mainly focused on the relationship between the size of the prolapse and injury to the supporting tissues, but the strain and stress distributions of the supporting tissues as well as high-risk areas of injury are still unknown. To further investigate the effect of supporting tissues on organs and the interactions between organs, this study focused on the relationship between high intra-abdominal pressure and the compliance of the pelvic floor support system in a normal woman without pelvic organ prolapse (POP), using a finite element model of the whole pelvic support system. A healthy female volunteer (55 years old) was scanned using magnetic resonance imaging (MRI) during rest and Valsalva maneuver. According to the pelvic structure contours traced by a gynecologist and anatomic details measured from dynamic MRI, a finite element model of the whole pelvic support system was established, including the uterus, vagina with cavity, cardinal and uterosacral ligaments, levator ani muscle, rectum, bladder, perineal body, pelvis, and obturator internus and coccygeal muscles. This model was imported into ANSYS software, and an implicit iterative method was employed to simulate the biomechanical response with increasing intra-abdominal pressure. Stress and strain distributions of the vaginal wall showed that the posterior wall was more stable than the anterior wall under high intra-abdominal pressure. Displacement at the top of the vagina was larger than that at the bottom, especially in the anterior–posterior direction. These results imply potential injury areas with high intra-abdominal pressure in non-prolapsed women, and provide insight into clinical managements for the prevention and surgical repair plans of POP.
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Affiliation(s)
- Xiaode Liu
- X Lab, The Second Academy of China Aerospace Science and Industry Corporation, Beijing, China
- Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, China
| | - Qiguo Rong
- Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, China
| | - Yanan Liu
- Department of Obstetrics and Gynecology, Dongping County People’s Hospital, Taian, China
| | - Jianliu Wang
- Department of Obstetrics and Gynecology, Peking University People’s Hospital, Peking University, Beijing, China
- Beijing Key Laboratory of Female Pelvic Floor Disorders, The Research Center of Female Pelvic Floor Disorder Disease of Peking University, Beijing, China
- Joint International Research Center of Translational and Clinical Research, Beijing, China
| | - Bing Xie
- Department of Obstetrics and Gynecology, Peking University People’s Hospital, Peking University, Beijing, China
- Beijing Key Laboratory of Female Pelvic Floor Disorders, The Research Center of Female Pelvic Floor Disorder Disease of Peking University, Beijing, China
- Joint International Research Center of Translational and Clinical Research, Beijing, China
- Bing Xie,
| | - Shuang Ren
- Beijing Key Laboratory of Sports Injuries, Department of Sports Medicine, Institute of Sports Medicine of Peking University, Peking University Third Hospital, Beijing, China
- *Correspondence: Shuang Ren,
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Schmidt P, Chen L, DeLancey JO, Swenson CW. Preoperative level II/III MRI measures predicting long-term prolapse recurrence after native tissue repair. Int Urogynecol J 2022; 33:133-141. [PMID: 34043048 PMCID: PMC8626527 DOI: 10.1007/s00192-021-04854-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/09/2021] [Indexed: 01/03/2023]
Abstract
INTRODUCTION AND HYPOTHESIS To identify preoperative level II/III MRI measures associated with long-term recurrence after native tissue prolapse repair. METHODS Women who previously participated in pelvic floor research involving MRI prior to undergoing primary native tissue prolapse repair were recruited to return for repeat examination and MRI. Recurrence was defined by POP-Q (Ba/Bp > 0 or C > -4), repeat surgery, or pessary use. Preoperative MR images were used to perform five level II/III measurements including a new levator plate (LP) shape analysis at rest and maximal Valsalva. Principal component analysis (PCA) was used to evaluate LP shape variations. Principal component scores calculated for two independent shape variations were noted. RESULTS Thirty-five women were included with a mean follow-up of 13.2 ± 3.3 years. Nineteen (54%) were in the success group. There were no statistical differences between success versus recurrence groups in demographic, clinical, or surgical characteristics. Women with recurrence had a larger preoperative resting levator hiatus [median 6.4 cm (IQR 5.7, 7.1) vs. 5.8 cm (IQR 5.3, 6.3), p = 0.03]. This measure was associated with increased odds of recurrence (OR 8.2, CI 1.4-48.9, p = 0.02). Using PCA, preoperative LP shape PC1 scores were different between success and recurrence groups (p = 0.02), with a more dorsally oriented LP shape associated with recurrence. CONCLUSIONS Larger preoperative levator hiatus at rest and a more dorsally oriented levator plate shape were associated with prolapse recurrence at long-term follow-up. For every 1 cm increase in preoperative resting levator hiatus, the odds of long-term prolapse recurrence increases 8-fold.
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Affiliation(s)
- Payton Schmidt
- Department of Obstetrics and Gynecology, University of Michigan, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA.
| | - Luyun Chen
- Department of Obstetrics and Gynecology, University of Michigan, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - John O DeLancey
- Department of Obstetrics and Gynecology, University of Michigan, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA
| | - Carolyn W Swenson
- Department of Obstetrics and Gynecology, University of Michigan, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA
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Babinski MDSD, Pires LAS, Fonseca Junior A, Manaia JHM, Babinski MA. Fibrous components of extracellular matrix and smooth muscle of the vaginal wall in young and postmenopausal women: Stereological analysis. Tissue Cell 2021; 74:101682. [PMID: 34800880 DOI: 10.1016/j.tice.2021.101682] [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: 08/09/2021] [Revised: 10/25/2021] [Accepted: 11/09/2021] [Indexed: 10/19/2022]
Abstract
The anterior vaginal wall is subject to many diseases, such as pelvic organ prolapse. The pathophysiology of this illness is multifactorial, and as such, structural components of the vagina are involved. Furthermore, it is more prevalent in older women. There is a lack of data in the literature regarding the extracellular matrix components of the vaginal wall and its changes with aging. The work presented herein aims to perform a stereological study of the extracellular matrix in young and old women. It was observed a decrease of the volumetric density of smooth muscle (45.5 ± 3.2 % and 32.8 ± 5.8 % for the G1 and G2 samples, respectively) and an increase of collagen and elastic fibers with age (35.9 ± 2.1 % and 54.1 ± 5.9 % for the G1 and G2, respectively) in the mucosa of the vaginal wall. These results could help to better understand the pathophysiology of pelvic organ prolapse concerning the aging process.
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Affiliation(s)
- Monique da Silva Dias Babinski
- Experimental Morphology Research Unit, Morphology Department, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Medical Sciences Post Graduation Program, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Lucas Alves Sarmento Pires
- Experimental Morphology Research Unit, Morphology Department, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Medical Sciences Post Graduation Program, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Albino Fonseca Junior
- Experimental Morphology Research Unit, Morphology Department, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Medical Sciences Post Graduation Program, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Jorge Henrique Martins Manaia
- Experimental Morphology Research Unit, Morphology Department, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Medical Sciences Post Graduation Program, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil
| | - Marcio Antonio Babinski
- Experimental Morphology Research Unit, Morphology Department, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil; Medical Sciences Post Graduation Program, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil.
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Kieserman-Shmokler C, Swenson CW, Chen L, Desmond LM, Ashton-Miller JA, DeLancey JO. From molecular to macro: the key role of the apical ligaments in uterovaginal support. Am J Obstet Gynecol 2020; 222:427-436. [PMID: 31639371 DOI: 10.1016/j.ajog.2019.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/05/2019] [Accepted: 10/12/2019] [Indexed: 01/22/2023]
Abstract
To explain the pathophysiology of pelvic organ prolapse, we must first understand the complexities of the normal support structures of the uterus and vagina. In this review, we focus on the apical ligaments, which include the cardinal and uterosacral ligaments. The aims of this review are the following: (1) to provide an overview of the anatomy and histology of the ligaments; (2) to summarize the imaging and biomechanical studies of the ligament properties and the way they relate to anterior and posterior vaginal wall prolapse; and (3) to synthesize these findings into a conceptual model for the progression of prolapse.
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Ultrasound imaging of the perineal body: a useful clinical tool. Int Urogynecol J 2019; 31:1197-1202. [PMID: 31828399 PMCID: PMC7270988 DOI: 10.1007/s00192-019-04166-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 10/25/2019] [Indexed: 11/30/2022]
Abstract
Introduction and hypothesis The perineal body is a fibromuscular pyramidal structure located between the vagina and the anus. It has been difficult to image because of its small size and anatomical location. This study used 2D transperineal ultrasound to measure the perineal body and assess whether there is an association with prolapse. Methods An observational, cross-sectional study was carried out in a tertiary level Urogynaecology department and included prolapse patients and healthy nulliparous volunteers (control group). This was a clinical assessment, including POP-Q and trans-perineal 2D ultrasound measurement of the perineal body height, length, perimeter, and area. Parametric tests were used, as the data were normally distributed. Results are reported as mean and 95% confidence interval (±95% CI). Results A total of 101 participants were recruited of which 22 were nulliparous healthy volunteers. Mean perineal body measurements in controls were height 22.5 ± 3.3 mm, length 17.4 ± 2.7 mm, perimeter 7.5 ± 0.9 mm, and area 2.8 ± 0.38 cm2. Perineal body measurements in 79 prolapse patients: height 16.9 ± 1.7 mm, length 16.0 ± 1.4 mm, perimeter 6.5 ± 0.5 mm and area 2.1 ± 0.5 cm2. A small perineal body was strongly associated with posterior compartment prolapse (paired t test, p < 0.0001) and wider POP-Q GH (paired t test, p = 0.0003). Surprisingly, Pelvic Organ Prolapse Quantification Perineal Body (POP-Q PB) of the two groups was not significantly different. A perineal body mid-sagittal area of less than 2.4 cm2 has been shown to be associated strongly with posterior compartment prolapse. Conclusions It is possible to measure the perineal body on 2D ultrasound. This technique facilitates the objective diagnosis of perineal deficiency. POP-Q PB does not predict the length or area of the perineal body.
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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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Comparison of measurement systems for posterior vaginal wall prolapse on magnetic resonance imaging. Int Urogynecol J 2019; 30:1269-1277. [PMID: 30972442 DOI: 10.1007/s00192-019-03939-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 03/20/2019] [Indexed: 10/27/2022]
Abstract
INTRODUCTION AND HYPOTHESIS A wide variety of reference lines and landmarks have been used in imaging studies to diagnose and quantify posterior vaginal wall prolapse without consensus. We sought to determine which is the best system to (1) identify posterior vaginal wall prolapse and its appropriate cutoff values and (2) assess the prolapse size. METHODS This was a secondary analysis of sagittal maximal Valsalva dynamic MRI scans from 52 posterior-predominant prolapse cases and 60 comparable controls from ongoing research. All eight existing measurement lines and a new parameter, the exposed vaginal length, were measured. Expert opinions were used to score the prolapse sizes. Simple linear regressions, effect sizes, area under the curve, and classification and regression tree analyses were used to compare these reference systems and determine cutoff values. Linear and ordinal logistic regressions were used to assess the effectiveness of the prolapse size. RESULTS Among existing parameters, "the perineal line-internal pubis," a reference line from the inside of the pubic symphysis to the front tip of the perineal body (cutoff value 0.9 cm), had the largest effect size (1.61), showed the highest sensitivity and specificity to discriminate prolapse with area under the curve (0.91), and explained the most variation (68%) in prolapse size scores. The exposed vaginal length (cutoff value 2.9) outperformed all the existing lines, with the largest effect size (2.09), area under the curve (0.95), and R-squared value (0.77). CONCLUSIONS The exposed vaginal length performs slightly better than the best of the existing systems, for both diagnosing and quantifying posterior prolapse size. Performance characteristics and evidence-based cutoffs might be useful in clinical practice.
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Kim KY, Cheng JW, Shen JK, Wagner H, Staack A. Translabial Ultrasound Evaluation of Pelvic Floor Structures and Mesh in the Urology Office and Intraoperative Setting. Urology 2018; 120:267. [PMID: 30031831 DOI: 10.1016/j.urology.2018.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/17/2018] [Accepted: 07/04/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Translabial ultrasound (TUS) can provide an inexpensive alternative imaging modality for evaluating pelvic floor structures and synthetic slings as mesh can be difficult to identify on pelvic exam or cystoscopy, patients may be unable to provide an accurate history of previous pelvic surgery, and cross-sectional imaging with computed tomography and magnetic resonance imaging can be inadequate for evaluating synthetic slings. OBJECTIVE To demonstrate the use of TUS in the evaluation of female pelvic floor structures and mesh. METHODS Translabial ultrasound can be used in the Urology clinic or intraoperative setting using a curvilinear transducer. Following identification of anatomic landmarks in the various planes of the pelvic floor, TUS can evaluate for pelvic floor disorders and the type and location of synthetic mesh material. Artifacts, such as air pockets in the vagina or rectum and the hypoechoic pubic symphysis, are also considered. RESULTS Real-time imaging allows for dynamic examination of pelvic organ prolapse and urethral hypermobility that can contribute to pelvic exam findings. Bladder ultrasound can help evaluate for lesions, calculi, and even mesh erosion. Translabial ultrasound can also be used to differentiate hyperechoic retropubic and transobturator slings by identifying the position of sling arms and the appearance of the sling at different planes. Evaluation with TUS can demonstrate sling disruption, folding, urethral impingement, and erosion into pelvic floor structures. This can be particularly useful in patients presenting with pain, recurrent infections, or voiding dysfunction in which problems with mesh may not be easily identified on pelvic exam or cystoscopy. This imaging modality can complement a patient's history, aid in preoperative planning, and enable intraoperative identification of mesh slings. CONCLUSION Translabial ultrasound provides a quick, readily available, and easy-to-learn imaging modality for evaluating pelvic floor structures and mesh in the office or intraoperative setting.
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Affiliation(s)
- Kevin Y Kim
- Department of Urology, Loma Linda University Health, Loma Linda, CA
| | - Julie W Cheng
- Department of Urology, Loma Linda University Health, Loma Linda, CA.
| | - Jim K Shen
- Department of Urology, Loma Linda University Health, Loma Linda, CA
| | - Hillary Wagner
- Department of Urology, Loma Linda University Health, Loma Linda, CA
| | - Andrea Staack
- Department of Urology, Loma Linda University Health, Loma Linda, CA
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Abstract
PURPOSE OF REVIEW Provide an evidence-based review of pelvic floor functional anatomy related to pelvic organ prolapse. RECENT FINDINGS Pelvic organ support depends on interactions between the levator ani muscle and pelvic connective tissues. Muscle failure exposes the vaginal wall to a pressure differential producing abnormal tension on the attachments of the pelvic organs to the pelvic sidewall. Birth-induced injury to the pubococcygeal portion of the levator ani muscle is seen in 55% of women with prolapse and 16% of women with normal support. Failure of the lateral connective tissue attachments between the uterus and vagina to the pelvic wall (cardinal, uterosacral, and paravaginal) are strongly related with prolapse (effect sizes ∼2.5) and are also highly correlated with one another (r ∼ 0.85). Small differences exist with prolapse in factors involving the vaginal wall length and width (effect sizes ∼1). The primary difference in ligament properties between women with and without prolapse is found in ligament length. Only minor differences in ligament stiffness are seen. SUMMARY Pelvic organ prolapse occurs because of injury to the levator ani muscles and failure of the lateral connections between the pelvic organs to the pelvic sidewall. Abnormalities of the vaginal wall fascial tissues may play a minor role.
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Structural Failure Sites in Anterior Vaginal Wall Prolapse: Identification of a Collinear Triad. Obstet Gynecol 2017; 128:853-862. [PMID: 27607881 DOI: 10.1097/aog.0000000000001652] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To test the null hypothesis that six factors representing potential fascial and muscular failure sites contribute equally to the presence and size of a cystocele: two vaginal attachment factors (apical support and paravaginal defects), two vaginal wall factors (vaginal length and width), and two levator ani factors (hiatus size and levator ani defects). METHODS Thirty women with anterior-predominant prolapse (women in a case group) and 30 women in a control group underwent three-dimensional stress magnetic resonance imaging. The location of the anterior vaginal wall at maximal Valsalva was identified with the modified Pelvic Inclination Coordinate System and the six factors measured. Analysis included repeated-measure analysis of variance, logistic regression, and stepwise linear regression. RESULTS We identified a collinear triad consisting of apical location, paravaginal location, and hiatus size that were not only the strongest predictors of cystocele size, but were also highly correlated with one another (r=0.84-0.89, P<.001) for the presence and size of the prolapse. Together they explain up to 83% of the variation in cystocele size. Among the less significant vaginal factors, vaginal length explained 19% of the variation in cystocele size, but no significant difference in vaginal width existed. Women in the case group were more likely to have abnormalities in collinear triad factors (up to 80%) than vaginal wall factors (up to 23.3%). Combining the strongest collinear triad with the vaginal factors, the model explained 92.5% of the variation in cystocele size. CONCLUSION Apical location, paravaginal location, and hiatus size are highly correlated and are strong predictors of cystocele presence and size.
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Chanda A, Unnikrishnan V, Richter HE, Lockhart ME. A biofidelic computational model of the female pelvic system to understand effect of bladder fill and progressive vaginal tissue stiffening due to prolapse on anterior vaginal wall. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2016; 32:e02767. [PMID: 26732347 DOI: 10.1002/cnm.2767] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 12/23/2015] [Accepted: 12/27/2015] [Indexed: 06/05/2023]
Abstract
Treatment of anterior vaginal prolapse (AVP), suffered by over 500,000 women in the USA, is a challenge in urogynecology because of the poorly understood mechanics of AVP. Recently, computational modeling combined with finite element method has been used to model AVP through the study of pelvic floor muscle and connective tissue impairments on the anterior vaginal wall (AVW). Also, the effects of pelvic organ displacements on the AVW were studied numerically. In our current work, an MRI-based full-scale biofidelic computational model of the female pelvic system composed of the urinary bladder, vaginal canal, and the uterus was developed, and a novel finite element method framework was employed to simulate vaginal tissue stiffening and also bladder filling due to expansion for the first time. A mesh convergence study was conducted to choose a computationally efficient mesh, and a non-linear hyperelastic Yeoh's material model was adopted for the study. The AVW displacements, mechanical stresses, and strains were estimated at varying degrees of bladder fills and vaginal tissue stiffening. Both bladder filling and vaginal stiffening were found to increase the stress concentration on the AVW with varying trends, which have been discussed in detail in the paper. To our knowledge, this study is the first to estimate the individual and combined effects of bladder filling and vaginal tissue stiffening due to prolapse on the AVW. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Arnab Chanda
- Department of Aerospace Engineering and Mechanics, University of Alabama, Tuscaloosa, 35487, AL, USA
| | - Vinu Unnikrishnan
- Department of Aerospace Engineering and Mechanics, University of Alabama, Tuscaloosa, 35487, AL, USA.
| | - Holly E Richter
- Division of Urogynecology and Pelvic Reconstructive Surgery, Department of Obstetrics and Gynecology, University of Alabama at Birmingham, 1720 2nd Ave S, Birmingham, AL, 35233, USA
| | - Mark E Lockhart
- Department of Radiology, University of Alabama at Birmingham, 1720 2nd Ave S, Birmingham, AL, 35233, USA
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Paravaginal defect: anatomy, clinical findings, and imaging. Int Urogynecol J 2016; 28:661-673. [PMID: 27640064 DOI: 10.1007/s00192-016-3096-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/07/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION AND HYPOTHESIS The paravaginal defect has been a topic of active discussion concerning what it is, how to diagnose it, its role in anterior vaginal wall prolapse, and if and how to repair it. The aim of this article was to review the existing literature on paravaginal defect and discuss its role in the anterior vaginal wall support system, with an emphasis on anatomy and imaging. METHODS Articles related to paravaginal defects were identified through a PubMed search ending 1 July 2015. RESULTS Support of the anterior vaginal wall is a complex system involving levator ani muscle, arcus tendineus fascia pelvis (ATFP), pubocervical fascia, and uterosacral/cardinal ligaments. Studies conclude that physical examination is inconsistent in detecting paravaginal defects. Ultrasound (US) and magnetic resonance imaging (MRI) have been used to describe patterns in the appearance of the vagina and bladder when a paravaginal defect is suspected. Different terms have been used (e.g., sagging of bladder base, loss of tenting), which all represent changes in pelvic floor support but that could be due to both paravaginal and levator ani defects. CONCLUSION Paravaginal support plays a role in supporting the anterior vaginal wall, but we still do not know the degree to which it contributes to the development of prolapse. Both MRI and US are useful in the diagnosis of paravaginal defects, but further studies are needed to evaluate their use.
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Alperin M, Cook M, Tuttle LJ, Esparza MC, Lieber RL. Impact of vaginal parity and aging on the architectural design of pelvic floor muscles. Am J Obstet Gynecol 2016; 215:312.e1-9. [PMID: 26953079 PMCID: PMC5003683 DOI: 10.1016/j.ajog.2016.02.033] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 01/11/2016] [Accepted: 02/12/2016] [Indexed: 01/18/2023]
Abstract
BACKGROUND Vaginal delivery and aging are key risk factors for pelvic floor muscle dysfunction, which is a critical component of pelvic floor disorders. However, alterations in the pelvic floor muscle intrinsic structure that lead to muscle dysfunction because of childbirth and aging remain elusive. OBJECTIVES The purpose of this study was to determine the impact of vaginal deliveries and aging on human cadaveric pelvic floor muscle architecture, which is the strongest predictor of active muscle function. STUDY DESIGN Coccygeus, iliococcygeus, and pubovisceralis were obtained from younger donors who were ≤51 years old, vaginally nulliparous (n = 5) and vaginally parous (n = 6) and older donors who were >51 years old, vaginally nulliparous (n = 6) and vaginally parous (n = 6), all of whom had no history of pelvic floor disorders. Architectural parameters, which are predictive of muscle's excursion and force-generating capacity, were determined with the use of validated methods. Intramuscular collagen content was quantified by hydroxyproline assay. Main effects of parity and aging and the interactions were determined with the use of 2-way analysis of variance, with Tukey's post-hoc testing and a significance level of .05. RESULTS The mean age of younger and older donors differed by approximately 40 years (P = .001) but was similar between nulliparous and parous donors within each age group (P > .9). The median parity was 2 (range, 1-3) in younger and older vaginally parous groups (P = .7). The main impact of parity was increased fiber length in the more proximal coccygeus (P = .03) and iliococcygeus (P = .04). Aging changes manifested as decreased physiologic cross-sectional area across all pelvic floor muscles (P < .05), which substantially exceeded the age-related decline in muscle mass. The physiologic cross-sectional area was lower in younger vaginally parous, compared with younger vaginally nulliparous, pelvic floor muscles; however, the differences did not reach statistical significance. Pelvic floor muscle collagen content was not altered by parity but increased dramatically with aging (P < .05). CONCLUSIONS Increased fiber length in more proximal pelvic floor muscles likely represents an adaptive response to the chronically increased load placed on these muscles by the displaced apical structures, presumably as a consequence of vaginal delivery. In younger specimens, a consistent trend towards decrease in force-generating capacity of all pelvic floor muscles in the parous group suggests a potential mechanism for clinically identified pelvic floor muscle weakness in vaginally parous women. The substantial decrease in predicted muscle force production and fibrosis with aging represent likely mechanisms for the pelvic floor muscle dysfunction in older women.
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Affiliation(s)
- Marianna Alperin
- Division of Urogynecology and Pelvic Reconstructive Surgery, the Department of Reproductive Medicine, University of California, San Diego, San Diego, CA.
| | - Mark Cook
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN
| | - Lori J Tuttle
- Exercise and Nutritional Sciences Physical Therapy, San Diego State University, San Diego CA
| | - Mary C Esparza
- Department of Orthopaedic Surgery, University of California, San Diego, San Diego, CA
| | - Richard L Lieber
- Department of Orthopaedic Surgery, University of California, San Diego, San Diego, CA; Department of Bioengineering, University of California, San Diego, San Diego, CA; Rehabilitation Institute of Chicago, Chicago, IL
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A multi-compartment 3-D finite element model of rectocele and its interaction with cystocele. J Biomech 2015; 48:1580-6. [PMID: 25757664 DOI: 10.1016/j.jbiomech.2015.02.041] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 02/17/2015] [Indexed: 11/21/2022]
Abstract
We developed a subject-specific 3-D finite element model to understand the mechanics underlying formation of female pelvic organ prolapse, specifically a rectocele and its interaction with a cystocele. The model was created from MRI 3-D geometry of a healthy 45 year-old multiparous woman. It included anterior and posterior vaginal walls, levator ani muscle, cardinal and uterosacral ligaments, anterior and posterior arcus tendineus fascia pelvis, arcus tendineus levator ani, perineal body, perineal membrane and anal sphincter. Material properties were mostly from the literature. Tissue impairment was modeled as decreased tissue stiffness based on previous clinical studies. Model equations were solved using Abaqus v 6.11. The sensitivity of anterior and posterior vaginal wall geometry was calculated for different combinations tissue impairments under increasing intraabdominal pressure. Prolapse size was reported as pelvic organ prolapse quantification system (POP-Q) point at point Bp for rectocele and point Ba for cystocele. Results show that a rectocele resulted from impairments of the levator ani and posterior compartment support. For 20% levator and 85% posterior support impairments, simulated rectocele size (at POP-Q point: Bp) increased 0.29 mm/cm H2O without apical impairment and 0.36 mm/cm H2O with 60% apical impairment, as intraabdominal pressures increased from 0 to 150 cm H2O. Apical support impairment could result in the development of either a cystocele or rectocele. Simulated repair of posterior compartment support decreased rectocele but increased a preexisting cystocele. We conclude that development of rectocele and cystocele depend on the presence of anterior, posterior, levator and/or or apical support impairments, as well as the interaction of the prolapse with the opposing compartment.
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Relationship between intra-abdominal pressure and vaginal wall movements during Valsalva in women with and without pelvic organ prolapse: technique development and early observations. Int Urogynecol J 2014; 25:873-81. [PMID: 24474605 DOI: 10.1007/s00192-013-2298-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 12/01/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVES To develop and test a method for measuring the relationship between the rise in intra-abdominal pressure and sagittal plane movements of the anterior and posterior vaginal walls during Valsalva in a pilot sample of women with and without prolapse. METHODS Mid-sagittal MRI images were obtained during Valsalva while changes in intra-abdominal pressure were measured via a bladder catheter in 5 women with cystocele, 5 women with rectocele, and 5 controls. The regional compliance of the anterior and posterior vagina wall support systems were estimated from the ratio of displacement (mm) of equidistant points along the anterior and posterior vaginal walls to intra-abdominal pressure rise (mmHg). RESULTS The compliance of both anterior and posterior vaginal wall support systems varied along different regions of vaginal wall for all three groups, with the highest compliance found near the vaginal apex and the lowest near the introitus. Women with cystocele had more compliant anterior and posterior vaginal wall support systems than women with rectocele. The movement direction differs between cystocele and rectocele. In cystocele, the anterior vaginal wall moves mostly toward the vaginal orifice in the upper vagina, but in a ventral direction in the lower vagina. In rectocele, the direction of the posterior vaginal wall movement is generally toward the vaginal orifice. CONCLUSIONS Movement of the vaginal wall and compliance of its support is quantifiable and was found to vary along the length of the vagina. Compliance was greatest in the upper vagina of all groups. Women with cystocele demonstrated the most compliant vaginal wall support.
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Brandão S, Da Roza T, Parente M, Ramos I, Mascarenhas T, Natal Jorge RM. Magnetic resonance imaging of the pelvic floor: from clinical to biomechanical imaging. Proc Inst Mech Eng H 2013; 227:1324-32. [PMID: 24030164 DOI: 10.1177/0954411913502952] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article reviews the current role of magnetic resonance imaging in the study of the pelvic floor anatomy and pelvic floor dysfunction. The application of static and dynamic magnetic resonance imaging in the clinical context and for biomechanical simulation modeling is assessed, and the main findings are summarized. Additionally, magnetic resonance-based diffusion tensor imaging is presented as a potential tool to evaluate muscle fiber morphology. In this article, focus is set on pelvic floor muscle damage related to urinary incontinence and pelvic organ prolapse, sometimes as a consequence of vaginal delivery. Modeling applications that evaluate anatomical and physiological properties of pelvic floor are presented to further illustrate their particular characteristics. Finally, finite element method is described as a method for modeling and analyzing pelvic floor structures' biomechanical performance, based on material and behavioral properties of the tissues, and considering pressure loads that mimic real-life conditions such as active contraction or Valsalva maneuver.
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Affiliation(s)
- Sofia Brandão
- Department of Radiology, Centro Hospitalar de São João-EPE, Porto, Portugal
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Luo J, Betschart C, Chen L, Ashton-Miller JA, DeLancey JOL. Using stress MRI to analyze the 3D changes in apical ligament geometry from rest to maximal Valsalva: a pilot study. Int Urogynecol J 2013; 25:197-203. [PMID: 24008367 DOI: 10.1007/s00192-013-2211-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 08/10/2013] [Indexed: 11/26/2022]
Abstract
INTRODUCTION AND HYPOTHESIS A method was developed using 3D stress magnetic resonance imaging (MRI) and was piloted to test hypotheses concerning changes in apical ligament lengths and lines of action from rest to maximal Valsalva. METHODS Ten women with (cases) and ten without (controls) pelvic organ prolapse (POP) were selected from an ongoing case-control study. Supine, multiplanar stress MRI was performed at rest and at maximal Valsalva and was imported into 3D Slicer v. 3.4.1 and aligned. The 3D reconstructions of the uterus and vagina, cardinal ligament (CL), deep uterosacral ligament (USL(d)), and pelvic bones were created. Ligament length and orientation were then measured. RESULTS Adequate ligament representations were possible in all 20 study participants. When cases were compared with controls, the curve length of the CL at rest was 71 ±16 mm vs. 59 ± 9 mm (p = 0.051), and the USL(d)was 38 ± 16 mm vs. 36 ± 11 mm (p = 0.797). Similarly, the increase in CL length from rest to strain was 30 ± 16 mm vs. 15 ± 9 mm (p = 0.033), and USL(d) was 15 ± 12 mm vs. 7 ± 4 mm (p = 0.094). Likewise, the change in USL(d) angle was significantly different from CL (p < 0.001). CONCLUSIONS This technique allows quantification of 3D geometry at rest and at strain. In our pilot sample, at maximal Valsalva, CL elongation was greater in cases than controls, whereas USL(d) was not; CL also exhibited greater changes in ligament length, and USL(d) exhibited greater changes in ligament inclination angle.
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Affiliation(s)
- Jiajia Luo
- Pelvic Floor Research Group, University of Michigan, Ann Arbor, MI, USA,
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Chen L, Ramanah R, Hsu Y, Ashton-Miller JA, Delancey JOL. Cardinal and deep uterosacral ligament lines of action: MRI based 3D technique development and preliminary findings in normal women. Int Urogynecol J 2013; 24:37-45. [PMID: 22618207 PMCID: PMC3986864 DOI: 10.1007/s00192-012-1801-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 04/11/2012] [Indexed: 10/28/2022]
Abstract
INTRODUCTION AND HYPOTHESIS The cardinal ligament (CL) and deep uterosacral ligament (US) play a critical role in utero-vaginal support. This study aims to quantify their geometrical relationships in living women using a MRI-based 3D technique. METHODS The angles between ligaments, the ligaments length and curvature were assessed on 3D models constructed from twenty MRIs of volunteers with normal support. How angle variation theoretically affects ligament tension was investigated using a simplified biomechanical model. RESULTS The CLs are 18.1 ° ± 6.8 °(SD) from the cephalic-caudal body axis , and the USs are dorsally directed and 92.5 ° ± 13.5 from the body axis. The CLs are longer and more curved than US. The theoretical calculated tension on CL is 52 % larger than that on US. CONCLUSIONS The CL is relatively parallel to the body axis while the US is dorsally directed. The tensions on these ligaments are affected by their orientations.
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Affiliation(s)
- Luyun Chen
- Departments of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA.
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Assessment of women with defecatory dysfunction and manual splinting using dynamic pelvic floor magnetic resonance imaging. Female Pelvic Med Reconstr Surg 2012; 18:18-24. [PMID: 22453259 DOI: 10.1097/spv.0b013e31823bdb98] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE This study aimed to describe magnetic resonance imaging (MRI) findings in women with defecatory dysfunction who perform manual splinting. METHODS This is a retrospective study of 29 patients from a single urogynecology center who presented with complaints of defecatory dysfunction and who reported manual splinting to assist with bowel movements. Patients were scheduled for an MRI study with a novel "splinting" protocol to evaluate the effects of their manual splinting on the pelvic floor. The protocol involved asking patients to splint during the MRI, as they normally would when trying to defecate. The goal was to evaluate any change in pelvic anatomy and compensation for an anatomic defect that could potentially lead to their defecatory dysfunction. Magnetic resonance images of the pelvis were obtained at rest, with pelvic floor contraction, with Valsalva, and during manual splinting. These images were then reviewed by radiologists who evaluated various parameters, including anorectal angle, levator ani muscle integrity, and the presence of rectocele, cystocele, apical prolapse, and enterocele. The external and internal anal sphincters were also evaluated for continuity. RESULTS From September 2008 to October 2010, 29 women reported defecatory dysfunction and the need for manual splinting. Their mean (SD) age was 55.2 (10.5) years. Magnetic resonance images showed a rectocele in 86.2% of the study group, cystocele in 75.9%, enterocele in 10.3%, and a defect of the levator ani muscles in 17.2%. Twenty-one (72.4%) women had more than 1 of these defects. In addition, 27.6% had an anorectal angle less than 90 degrees or greater than 105 degrees.Patients in the study group splinted in the vagina (58.6%), on the perineum (31.0%), or on the buttock (10.3%). In all but 1 woman (96.6%), splinting improved or completely corrected the identified defect(s) as evidenced with MRI. Among those who used vaginal splinting, 52.9% of defects were corrected and 47.1% were improved. Perineal splinting corrected 55.6% and improved 33.3% of cases and was ineffective in 11.1% of cases, whereas buttock splinting corrected 33.3% and improved 66.7% of cases. CONCLUSIONS Most women in our study group who used manual splinting to assist in defecation are compensating for a pelvic floor defect that can be detected on MRI. Magnetic resonance imaging of the pelvis may help elucidate the etiology of the defecatory dysfunction in some women and may assist pelvic reconstructive surgeons in planning surgical correction of pelvic floor defects. Magnetic resonance imaging may also identify defects in the pelvic floor that are, at the present time, not amenable to surgical correction.
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Posterior vaginal prolapse shape and position changes at maximal Valsalva seen in 3-D MRI-based models. Int Urogynecol J 2012; 23:1301-6. [PMID: 22527556 DOI: 10.1007/s00192-012-1760-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 03/18/2012] [Indexed: 01/04/2023]
Abstract
INTRODUCTION AND HYPOTHESIS Two-dimensional magnetic resonance imaging (MRI) of posterior vaginal prolapse has been studied. However, the three-dimensional (3-D) mechanisms causing such prolapse remain poorly understood. This discovery project was undertaken to identify the different 3-D characteristics of models of rectocele-type posterior vaginal prolapse (PVP(R)) in women. METHODS Ten women with (cases) and ten without (controls) PVP(R) were selected from an ongoing case-control study. Supine, multiplanar MR imaging was performed at rest and maximal Valsalva. Three-dimensional reconstructions of the posterior vaginal wall and pelvic bones were created using 3D Slicer v. 3.4.1. In each slice the posterior vaginal wall and perineal skin were outlined to the anterior margin of the external anal sphincter to include the area of the perineal body. Women with predominant enteroceles or anterior vaginal prolapse were excluded. RESULTS The case and control groups had similar demographics. In women with PVP(R) two characteristics were consistently visible (10/10): (1) the posterior vaginal wall displayed a folding phenomenon similar to a person beginning to kneel ("kneeling" shape) and (2) a downward displacement in the upper two thirds of the vagina. Also seen in some, but not all of the scans were: (3) forward protrusion of the distal vagina (6/10), (4) perineal descent (5/10), and (5) distal widening in the lower third of the vagina (3/10). CONCLUSIONS Increased folding (kneeling) of the vagina and an overall downward displacement are consistently present in rectocele. Forward protrusion, perineal descent, and distal widening are sometimes seen as well.
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Larson KA, Luo J, Guire KE, Chen L, Ashton-Miller JA, DeLancey JOL. 3D analysis of cystoceles using magnetic resonance imaging assessing midline, paravaginal, and apical defects. Int Urogynecol J 2011; 23:285-93. [PMID: 22068322 DOI: 10.1007/s00192-011-1586-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 10/06/2011] [Indexed: 01/08/2023]
Abstract
INTRODUCTION AND HYPOTHESIS This study assesses relative contributions of "midline defects" (widening of the vagina) and "paravaginal defects" (separation of the lateral vagina from the pelvic sidewall). METHODS Ten women with anterior predominant prolapse and ten with normal support underwent pelvic MR imaging. 3-D models of the anterior vaginal wall (AVW) were generated to determine locations of the lateral AVW margin, vaginal width, and apical position. RESULTS The lateral AVW margin was farther from its normal position in cases than controls throughout most of the vaginal length, most pronounced midvagina (effect sizes, 2.2-2.8). Vaginal widths differed in the midvagina with an effect size of 1.0. Strong correlations between apical and paravaginal support were evident in mid- and upper vagina (r = 0.77-0.93). CONCLUSIONS Changes in lateral AVW location were considerably greater than changes in vaginal width in cases vs controls, both in number of sites affected and effect sizes. These "paravaginal defects" are highly correlated with apical descent.
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Affiliation(s)
- Kindra A Larson
- Pelvic Floor Research Group, University of Michigan, Ann Arbor, MI, USA.
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Levator avulsion using a tomographic ultrasound and magnetic resonance-based model. Am J Obstet Gynecol 2011; 205:232.e1-8. [PMID: 21620359 DOI: 10.1016/j.ajog.2011.03.052] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 02/14/2011] [Accepted: 03/29/2011] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Delivery-related levator avulsion can cause pelvic floor dysfunction. We compared agreement between tomographic ultrasound and magnetic resonance-based models for the detection of levator defects. STUDY DESIGN Sixty-nine Chinese women with pelvic organ prolapse were assessed prospectively by 3-dimensional ultrasound scans and magnetic resonance imaging. Levator-urethra gap (LUG), levator-symphysis gap (LSG), and puborectalis attachment width were measured offline with state-of-the-art software. Interobserver variability and agreement between the 2 methods were determined. RESULTS Interobserver repeatability was moderate-to-excellent for all parameters that were measured with both methods and agreement between methods in diagnosing levator avulsion. LUG and LSG measurements were significantly higher in women with a levator avulsion. With a diagnosis of complete levator avulsion, receiver operating characteristics analysis suggested a cutoff of 23.65 mm for LUG and 28.7 mm for LSG. CONCLUSION Levator avulsion can be diagnosed reliably by tomographic ultrasound scanning and magnetic resonance imaging evaluation, and linear measures, such as LSG and LUG, can be proxy measurements for avulsion.
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