Structural Changes in Brain White Matter Tracts Associated With Overactive Bladder Revealed by Diffusion Tensor Magnetic Resonance Imaging: Findings From a Symptoms of Lower Urinary Tract Dysfunction Research Network Cross-Sectional Case-Control Study.

PURPOSE: Our objective was to investigate structural changes in brain white matter tracts using diffusion tensor imaging (DTI) in patients with overactive bladder (OAB). MATERIALS AND METHODS: Treatment-seeking OAB patients and matched controls enrolled in the cross-sectional case-control LURN (Symptoms of Lower Urinary Tract Dysfunction Research Network) Neuroimaging Study received a brain DTI scan. Microstructural integrity of brain white matter was assessed using fractional anisotropy (FA) and mean diffusivity. OAB and urgency urinary incontinence (UUI) symptoms were assessed using the OAB Questionnaire Short-Form and International Consultation on Incontinence Questionnaire-Urinary Incontinence. The Lower Urinary Tract Symptoms Tool UUI questions and responses were correlated with FA values. RESULTS: Among 221 participants with evaluable DTI data, 146 had OAB (66 urinary urgency-only without UUI, 80 with UUI); 75 were controls. Compared with controls, participants with OAB showed decreased FA and increased mean diffusivity, representing greater microstructural abnormalities of brain white matter tracts among OAB participants. These abnormalities occurred in the corpus callosum, bilateral anterior thalamic radiation and superior longitudinal fasciculus tracts, and bilateral insula and parahippocampal region. Among participants with OAB, higher OAB Questionnaire Short-Form scores were associated with decreased FA in the left inferior fronto-occipital fasciculus, P < .0001. DTI differences between OAB and controls were driven by the urinary urgency-only (OAB-dry) but not the UUI (OAB-wet) subgroup. CONCLUSIONS: Abnormalities in microstructural integrity in specific brain white matter tracts were more frequent in OAB patients. More severe OAB symptoms were correlated with greater degree of microstructural abnormalities in brain white matter tracts in patients with OAB.

Pelvic floor injury during vaginal birth is life-altering and preventable: what can we do about it?

Pelvic floor disorders after childbirth have distressing lifelong consequences for women, requiring more than 300,000 women to have surgery annually. This represents approximately 10% of the 3 million women who give birth vaginally each year. Vaginal birth is the largest modifiable risk factor for prolapse, the pelvic floor disorder most strongly associated with birth, and is an important contributor to stress incontinence. These disorders require 10 times as many operations as anal sphincter injuries. Imaging shows that injuries of the levator ani muscle, perineal body, and membrane occur in up to 19% of primiparous women. During birth, the levator muscle and birth canal tissues must stretch to more than 3 times their original length; it is this overstretching that is responsible for the muscle tear visible on imaging rather than compression or neuropathy. The injury is present in 55% of women with prolapse later in life, with an odds ratio of 7.3, compared with women with normal support. In addition, levator damage can affect other aspects of hiatal closure, such as the perineal body and membrane. These injuries are associated with an enlarged urogenital hiatus, now known as antedate prolapse, and with prolapse surgery failure. Risk factors for levator injury are multifactorial and include forceps delivery, occiput posterior birth, older maternal age, long second stage of labor, and birthweight of >4000 g. Delivery with a vacuum device is associated with reduced levator damage. Other steps that might logically reduce injuries include manual rotation from occiput posterior to occiput anterior, slow gradual delivery, perineal massage or compresses, and early induction of labor, but these require study to document protection. In addition, teaching women to avoid pushing against a contracted levator muscle would likely decrease injury risk by decreasing tension on the vulnerable muscle origin. Providing care for women who have experienced difficult deliveries can be enhanced with early recognition, physical therapy, and attention to recovery. It is only right that women be made aware of these risks during pregnancy. Educating women on the long-term pelvic floor sequelae of childbirth should be performed antenatally so that they can be empowered to make informed decisions about management decisions during labor.

Postpartum Changes in Levator Plate Shape and Genital Hiatus Size After Vaginal Delivery.

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.

Functional Anatomy of Urogenital Hiatus Closure: the Perineal Complex Triad Hypothesis.

INTRODUCTION: Urogenital hiatus enlargement is a critical factor associated with prolapse and operative failure. This study of the perineal complex was performed to understand how interactions among its three structures: the levator ani, perineal membrane, and perineal body-united by the vaginal fascia-work to maintain urogenital hiatus closure. METHODS: Magnetic resonance images from 30 healthy nulliparous women with 3D reconstruction of selected subjects were used to establish overall geometry. Connection points and lines of action were based on perineal dissection in 10 female cadavers (aged 22-86 years), cross sections of 4 female cadavers (aged 14-35 years), and histological sections (cadavers aged 16 and 21 years). RESULTS: The perineal membrane originates laterally from the ventral two thirds of the ischiopubic rami and attaches medially to the perineal body and vaginal wall. The levator ani attaches to the perineal membrane's cranial surface, vaginal fascia, and the perineal body. The levator line of action in 3D reconstruction is oriented so that the levator pulls the medial perineal membrane cranio-ventrally. In cadavers, simulated levator contraction and relaxation along this vector changes the length of the membrane and the antero-posterior diameter of the urogenital hiatus. Loss of the connection of the left and right perineal membranes through the perineal body results in diastasis of the levator and a widened hiatus, as well as a downward rotation of the perineal membrane. CONCLUSION: Interconnections involving the levator ani muscles, perineal membrane, perineal body, and vaginal fascia form the perineal complex surrounding the urogenital hiatus in an arrangement that maintains hiatal closure.

A unified pelvic floor conceptual model for studying morphological changes with prolapse, age, and parity.

Several 2-dimensional and 3-dimensional measurements have been used to assess changes in pelvic floor structures and shape. These include assessment of urogenital and levator hiatus dimensions, levator injury grade, levator bowl volume, and levator plate shape. We argue that each assessment reflects underlying changes in an individual aspect of the overall changes in muscle and fascial structures. Vaginal delivery, aging, and interindividual variations in anatomy combine to affect pelvic floor structures and their connections in different ways. To date, there is no unifying conceptual model that permits the evaluation of how these many measures relate to one another or that reflects overall pelvic floor structure and function. Therefore, this study aimed to describe a unified pelvic floor conceptual model to better understand how the aforementioned changes to the pelvic floor structures and their biomechanical interactions affect pelvic organ support with vaginal birth, prolapse, and age. In this model, the pelvic floor is composed of 5 key anatomic structures: the (1) pubovisceral, (2) puborectal, and (3) iliococcygeal muscles with their superficial and inferior fascia; (4) the perineal membrane or body; and (5) the anal sphincter complex. Schematically, these structures are considered to originate from pelvic sidewall structures and meet medially at important connection points that include the anal sphincter complex, perineal body, and anococcygeal raphe. The pubovisceral muscle contributes primarily to urogenital hiatus closure, whereas the puborectal muscle is mainly related to levator hiatus closure, although each muscle contributes to the other. Dorsally and laterally, the iliococcygeal muscle forms a shelflike structure in women with normal support that spans the remaining area between these medial muscles and attachments to the pelvic sidewall. Other features include the levator plate, bowl volume, and anorectal angle. The pelvic floor conceptual model integrates existing observations and points out evident knowledge gaps in how parturition, injury, disease, and aging can contribute to changes associated with pelvic floor function caused by the detachment of one or more important connection points or pubovisceral muscle failure.

Variations in structural support site failure patterns by prolapse size on stress 3D MRI.

INTRODUCTION AND HYPOTHESIS: Our objective was to develop a standardized measurement system to evaluate structural support site failures among women with anterior vaginal wall-predominant prolapse according to increasing prolapse size using stress three-dimensional (3D) magnetic resonance imaging (MRI). METHODS: Ninety-one women with anterior vaginal wall-predominant prolapse and uterus in situ who had undergone research stress 3D MRI were included for analysis. The vaginal wall length and width, apex and paravaginal locations, urogenital hiatus diameter, and prolapse size were measured at maximal Valsalva on MRI. Subject measurements were compared to established measurements in 30 normal controls without prolapse using a standardized z-score measurement system. A z-score greater than 1.28, or the 90th percentile in controls, was considered abnormal. The frequency and severity of structural support site failure was analyzed based on tertiles of prolapse size. RESULTS: Substantial variability in support site failure pattern and severity was identified, even between women with the same stage and similar size prolapse. Overall, the most common failed support sites were straining hiatal diameter (91%) and paravaginal location (92%), followed by apical location (82%). Impairment severity z-score was highest for hiatal diameter (3.56) and lowest for vaginal width (1.40). An increase in impairment severity z-score was observed with increasing prolapse size among all support sites across all three prolapse size tertiles (p < 0.01 for all). CONCLUSIONS: We identified substantial variation in support site failure patterns among women with different degrees of anterior vaginal wall prolapse using a novel standardized framework that quantifies the number, severity, and location of structural support site failures.

A comparison of MRI-based pelvic floor support measures between young and old women with prolapse.

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.

Hiatal failure: effects of pregnancy, delivery, and pelvic floor disorders on level III factors.

INTRODUCTION AND HYPOTHESIS: The failure of the levator hiatus (LH) and urogenital hiatus (UGH) to remain closed is not only associated with pelvic floor disorders, but also contributes to recurrence after surgical repair. Pregnancy and vaginal birth are key events affecting this closure. An understanding of normal and failed hiatal closure is necessary to understand, manage, and prevent pelvic floor disorders. METHODS: This narrative review was conducted by applying the keywords "levator hiatus" OR "genital hiatus" OR "urogenital hiatus" in PubMed. Articles that reported hiatal size related to pelvic floor disorders and pregnancy were chosen. Weighted averages for hiatal size were calculated for each clinical situation. RESULTS: Women with prolapse have a 22% and 30% larger LH area measured by ultrasound at rest and during Valsalva than parous women with normal support. Women with persistently enlarged UGH have 2-3 times higher postoperative failure rates after surgery for prolapse. During pregnancy, the LH area at Valsalva increases by 29% from the first to the third trimester in preparation for childbirth. The enlarged postpartum hiatus recovers over time, but does not return to nulliparous size after vaginal birth. Levator muscle injury during vaginal birth, especially forceps-assisted, is associated with increases in hiatal size; however, it only explains a portion of hiatus variation-the rest can be explained by pelvic muscle function and possibly injury to other level III structures. CONCLUSIONS: Failed hiatal closure is strongly related to pelvic floor disorders. Vaginal birth and levator injury are primary factors affecting this important mechanism.

Natural history of lower urinary tract symptoms in treatment-seeking women with pelvic organ prolapse; the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN).

BACKGROUND: The association of pelvic organ prolapse with overactive bladder and other lower urinary tract symptoms, and the natural history of those symptoms are not well characterized. Previous cross-sectional studies demonstrated conflicting relationships between prolapse and lower urinary tract symptoms. OBJECTIVE: This study primarily aimed to determine the baseline association between lower urinary tract symptoms and prolapse and to assess longitudinal differences in symptoms over 12 months in women with and without prolapse. Secondary aims were to explore associations between lower urinary tract symptoms and prolapse treatment. We hypothesized that: (1) prolapse is associated with the presence of lower urinary tract symptoms, (2) lower urinary tract symptoms are stable over time in patients with and without prolapse, and (3) prolapse treatment is associated with lower urinary tract symptom improvement. STUDY DESIGN: Women enrolled in the Symptoms of Lower Urinary Tract Dysfunction Research Network Observational Cohort Study with adequate 12-month follow-up data were included. Prolapse and lower urinary tract symptom treatment during follow-up was guided by standard of care. Outcome measures included the Lower Urinary Tract Symptoms Tool total severity score (in addition to overactive bladder, obstructive, and stress urinary incontinence subscales) and Urogenital Distress Inventory-6 Short Form. Prolapse (yes or no) was defined primarily when Pelvic Organ Prolapse Quantification System points Ba, C or Bp were >0 (beyond the hymen). Mixed-effects models with random effects for patient slopes and intercepts were fitted for each lower urinary tract symptom outcome and prolapse predictor, adjusted for other covariates. The study had >90% power to detect differences as small as 0.4 standard deviation for less prevalent group comparisons (eg, prolapse vs not). RESULTS: A total of 371 women were analyzed, including 313 (84%) with no prolapse and 58 (16%) with prolapse. Women with prolapse were older (64.6±8.8 vs 55.3±14.1 years; P<.001) and more likely to have prolapse surgery (28% vs 1%; P<.001) and pessary treatment (26% vs 4%; P<.001) during the study. Average baseline Lower Urinary Tract Symptoms Tool total severity scores were lower (fewer symptoms) for participants with prolapse compared with those without (38.9±14.0 vs 43.2±14.0; P=.036), but there were no differences in average scores between prolapse groups for other scales. For all urinary outcomes, average scores were significantly lower (improved) at 3 and 12 months compared with baseline (all P<.05). In mixed-effects models, there were no statistically significant interactions between pelvic organ prolapse measurement and visit and time-dependent prolapse treatment groups (P>.05 for all regression interaction coefficients). The Lower Urinary Tract Symptoms Tool obstructive severity score had a statistically significant positive association with Pelvic Organ Prolapse Quantification System Ba, Bp, and point of maximum vaginal descent. The Lower Urinary Tract Symptoms Tool total severity scale had a statistically significant negative association with Pelvic Organ Prolapse Quantification System Ba and point of maximum vaginal descent. No other associations between prolapse and lower urinary tract symptoms were significant (P>.05 for all regression coefficients). Symptom differences between prolapse groups were small: all regression coefficients (interpretable as additive percentage change in each score) were between -5 and 5 (standard deviation of outcomes ranged from 14.0-32.4). CONCLUSION: Among treatment-seeking women with urinary symptoms, obstructive symptoms were positively associated with prolapse, and overall lower urinary tract symptom severity was negatively associated with prolapse. Lower Urinary Tract Symptoms Tool scores improved over 12 months regardless of prolapse status, including in those with treated prolapse, untreated prolapse, and without prolapse.

Geometric analysis of the urethral-vaginal interface curvature in women with and without stress urinary incontinence: A pilot magnetic resonance imaging study.

AIMS: To evaluate differences in the curvature of the urethral-vaginal interface in women with and without stress urinary incontinence (SUI) using geometric morphometric analysis techniques. METHODS: We conducted a pilot case-control study using magnetic resonance imaging (MRI) scans of 18 women with and without SUI. The urethral-vaginal interface at the level of the mid-urethra was fitted with a second-order polynomial regression. The chord length and chord-to-vertex length of the resulting parabolic curve were used to calculate the arc length and radius of a circular arc fitted to the interface curvature. Demographic characteristics and Pelvic Organ Prolapse Quantification (POP-Q) parameters were collected. Subjects were stratified by those with and without SUI, as well as by those with and without anterior wall prolapse beyond 2 cm proximal to the hymen (Aa > -2 cm). RESULTS: The radius of the urethral-vaginal interface curvature was not found to be different between subjects with and without SUI (8.8 vs. 9.2 mm, p = 0.53); however, this value was smaller in subjects with Aa > -2 (8.4 vs. 11.9 mm, p = 0.03). The chord length, chord-to-vertex length, and arc length comprising the urethral-vaginal interface curvature were similar between subjects with and without SUI, and between subjects with and without Aa > -2 cm (p > 0.05 for all). CONCLUSIONS: In this pilot study population, the radius of the urethral-vaginal interface curvature at the mid-urethra was smaller among women with anterior vaginal wall prolapse beyond 2 cm proximal to the hymen. A difference in the urethral-vaginal interface curvature among women with and without SUI was not found.

Lies, damned lies, and pelvic floor illustration: Confused about pelvic floor anatomy? You are not alone.

Dissection reveals elegant simplicity in pelvic floor structure. So, why are so many of us confused about the pelvic floor? The pelvic floor is in an invisible region between what we see from above and below, so our experience does not help. It is confusing because there is conflict between existing illustrations, so we do not know which are false and which are true. To resolve conflicts in pelvic anatomy we must: recognize the Vesalian principle that truth lies in the body, not necessarily in books; commit to focusing on structures rather than words; and overcome "theory-induced blindness," the psychological principle that discounts what is seen when it contradicts a theory we believe. We should revive century-old standards that require accuracy in anatomical illustration analogous to the p value in statistics. Committing to anatomical accuracy will ensure that we no longer navigate in surgery and research using a flawed map.

Age, parity, and prolapse: interaction and influence on levator bowl volume.

INTRODUCTION AND HYPOTHESIS: The objective was to test the hypotheses that a linear relationship exists between age and levator bowl volume (LBV); and that age, parity, and prolapse are independently associated with LBV. METHODS: We conducted a secondary analysis of data from nulliparous women, parous controls, and prolapse (Pelvic Organ Prolapse Quantification (POP-Q) Ba ≥ 1 cm) cases from each of three age groups: young (≤40), mid-age (50-60), and older (≥70). LBV was measured using MRI at rest and Valsalva as the 3D space contained above the levator ani muscles and below the sacrococcygeal junction-to-inferior pubic point reference plane. Linear regression models were used to examine the effects of age, parity, prolapse, and their interactions (age*parity and age*prolapse) on LBV. RESULTS: Each group consisted of 9-12 women. LBVRest increased with age in a nonlinear fashion. For nulliparous women, the median value increased 4.7% per decade from the young to mid-age group and 84% per decade from the mid-age to older group; for parous controls, the corresponding increases were 38% and -0.5%; and for women with prolapse, they were 46% and 11%. Age and prolapse status (both p<0.001) were found to be significant independent predictors of LBVRest. Interactions between age*prolapse (p=0.003) and age*parity (p=0.045) were also independently associated with LBVRest. CONCLUSIONS: Parity and prolapse influence how age affects LBVRest. In nulliparous women, age had little effect on LBVRest until after mid-age. For women with prolapse, LBVRest increased at a much earlier age, with the biggest difference occurring between young and mid-age women.

Analysis of long-term structural failure after native tissue prolapse surgery: a 3D stress MRI-based study.

INTRODUCTION AND HYPOTHESIS: We sought to identify postoperative structural failure sites associated with long-term prolapse recurrence and their association with symptoms and satisfaction. METHODS: Women who had a research MRI prior to native-tissue prolapse surgery were recruited for examination, 3D stress MRI, and questionnaires. Recurrence was defined by Pelvic Organ Prolapse Quantification System (POP-Q)Ba/Bp > 0 or C > -4. Measurements were performed at rest and maximum Valsalva ("strain") including vaginal length, apex location, urogenital hiatus (UGH), and levator hiatus (LH). Measures were compared between subjects and to women with normal support. Failure frequency was the proportion of women with measurements outside the normal range. Symptoms and satisfaction were measured using validated questionnaires. RESULTS: Thirty-one women participated 12.7 years after surgery-58% with long-term success and 42% with recurrence. Failure site comparisons between success and failure were: impaired mid-vaginal paravaginal support (62% vs. 28%, p = 0.01), longer vaginal length (54% vs. 22%, p = 0.03), and enlarged urogenital hiatus (54% vs. 22%, p = 0.03). Apical paravaginal location had the lowest failure frequency (recurrence: 15% vs. success: 7%, p = 0.37). Patient satisfaction was high (recurrence: 5.0 vs. success: 5.0, p = 0.86). Women with bothersome bulge symptoms had a 33% larger UGH strain on POP-Q (p = 0.01), 8.7% larger resting UGH (p = 0.046), 11.5% larger straining LH (p = 0.01), and 9.3% larger resting LH (p = 0.01). CONCLUSIONS: Abnormal low mid-vaginal paravaginal location (Level II), long vaginal length (Level II), and large UGH (Level III) were associated with long-term prolapse recurrence. Patient satisfaction was high and unrelated to anatomical recurrence. Bothersome bulge symptoms were associated with hiatus enlargement.

Preoperative level II/III MRI measures predicting long-term prolapse recurrence after native tissue repair.

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.

Changes in cardinal ligament length and curvature with parity and prolapse and their relation to level III hiatus measures.

INTRODUCTION AND HYPOTHESIS: Test the hypotheses that (1) cardinal ligament (CL) straightening and lengthening occur with parity and prolapse, (2) CL straightening occurs before lengthening, and (3) CL length is correlated with level III measures. METHODS: We performed a secondary analysis of MRIs from women in three groups: (1) nulliparous with normal support, (2) parous with normal support, and (3) uterine prolapse (POP-Q point C > - 4 and Ba > 1 cm). The 3D stress MRI images at rest and maximal Valsalva were analyzed. CLs were traced from their origin to cervico-vaginal insertions. Curvature ratio was calculated as curved length/straight length. Level III measures included urogenital hiatus (UGH), levator hiatus (LH), and levator bowl volume (LBV), and their correlations with CL length were calculated. RESULTS: Ten women were included in each group. Compared to the nulliparous group, CL length was 18% longer in parous controls (p = .04) and 59% longer with prolapse (p < .01) at rest, while at Valsalva, CL length was 10% longer in parous controls (p = .21) and 49% longer with prolapse (p < .01). Curvature ratios showed 18% more straightening in women with prolapse compared to parous controls (p < .01). Curved CL length and level III measures were moderately to strongly correlated: UGH (rest: R = 0.68, p < .01; Valsalva: R =0.80, p < .01), LH (rest: R = 0.60, p < .01; Valsalva: R = 0.78, p < .01), and LBV (rest: R = 0.71, p < .01; Valsalva: R =0.89, p < .01). CONCLUSION: Our findings suggest that the CLs undergo three times as much lengthening with prolapse as with parity; however, straightening only occurs with prolapse. Strong correlations exist between level I and level III support.

Multi-label classification of pelvic organ prolapse using stress magnetic resonance imaging with deep learning.

INTRODUCTION AND HYPOTHESIS: We aimed to develop a deep learning-based multi-label classification model to simultaneously diagnose three types of pelvic organ prolapse using stress magnetic resonance imaging (MRI). METHODS: Our dataset consisted of 213 midsagittal labeled MR images at maximum Valsalva. For each MR image, the two endpoints of the sacrococcygeal inferior-pubic point line were auto-localized. Based on this line, a region of interest was automatically selected as input to a modified deep learning model, ResNet-50, for diagnosis. An unlabeled MRI dataset, a public dataset, and a synthetic dataset were used along with the labeled image dataset to train the model through a novel training strategy. We conducted a fivefold cross-validation and evaluated the classification results using precision, recall, F1 score, and area under the curve (AUC). RESULTS: The average precision, recall, F1 score, and AUC of our proposed multi-label classification model for the three types of prolapse were 0.84, 0.72, 0.77, and 0.91 respectively, which were improved from 0.64, 0.53, 0.57, and 0.83 from the original ResNet-50. Classification took 0.18 s to diagnose one patient. CONCLUSIONS: The proposed deep learning-based model were demonstrated feasible and fast in simultaneously diagnosing three types of prolapse based on pelvic floor stress MRI, which could facilitate computer-aided prolapse diagnosis and treatment planning.

Pelvic floor muscle injury during a difficult labor. Can tissue fatigue damage play a role?

Pubovisceral muscle (PVM) injury during a difficult vaginal delivery leads to pelvic organ prolapse later in life. If one could address how and why the muscle injury originates, one might be able to better prevent these injuries in the future. In a recent review we concluded that many atraumatic injuries of the muscle-tendon unit are consistent with it being weakened by an accumulation of passive tissue damage during repetitive loading. While the PVM can tear due to a single overstretch at the end of the second stage of labor we hypothesize that it can also be weakened by an accumulation of microdamage and then tear after a series of submaximal loading cycles. We conclude that there is strong indirect evidence that low cycle fatigue of PVM passive tissue is a possible mechanism of its proximal failure. This has implications for finding new ways to better prevent PVM injury in the future.

Pelvic inclination correction system for magnetic resonance imaging analysis of pelvic organ prolapse in upright position.

INTRODUCTION AND HYPOTHESIS: Pelvic organ prolapse quantification by means of upright magnetic resonance imaging (MRI) is a promising research field. This study determines the angle for the pelvic inclination correction system (PICS) for upright patient position, which is hypothesized to deviate from the supine PICS angle. The necessity of different PICS angles for various patient positions will also be discussed. METHODS: Magnetic resonance scans of 113 women, acquired in an upright patient position, were used to determine the upright PICS angle, defined as the angle between the sacrococcygeal-inferior pubic point (SCIPP) line and the horizontal line. The difference and correlation between the upright and supine PICS angles were calculated using the paired Student's t-test and the Pearson's correlation coefficient (r) respectively. The effect of the difference between the upright and supine PICS angle on the measured pelvic organ extent was calculated using goniometry. RESULTS: The mean (interquartile range) PICS angles were 29° (26-35°) for the upright and 33° (30-37°) for the supine patient position. They were significantly different (p<0.001) and very strongly correlated (r = 0.914, p<0.001). The 4° difference between the average upright and supine PICS angle results in an average underestimation of the measured cervix height of approximately 0.5 cm for patients scanned in upright position. CONCLUSIONS: The PICS angle for the upright patient position is 29°. The use of a dedicated PICS angle for different patient positions allows for more accurate pelvic organ extent analysis in patients with prolapse.

Recommended standardized anatomic terminology of the posterior female pelvis and vulva based on a structured medical literature review.

BACKGROUND: Anatomic terminology in both written and verbal forms has been shown to be inaccurate and imprecise. OBJECTIVE: Here, we aimed to (1) review published anatomic terminology as it relates to the posterior female pelvis, posterior vagina, and vulva; (2) compare these terms to "Terminologia Anatomica," the internationally standardized terminology; and (3) compile standardized anatomic terms for improved communication and understanding. STUDY DESIGN: From inception of the study to April 6, 2018, MEDLINE database was used to search for 40 terms relevant to the posterior female pelvis and vulvar anatomy. Furthermore, 11 investigators reviewed identified abstracts and selected those reporting on posterior female pelvic and vulvar anatomy for full-text review. In addition, 11 textbook chapters were included in the study. Definitions of all pertinent anatomic terms were extracted for review. RESULTS: Overall, 486 anatomic terms were identified describing the vulva and posterior female pelvic anatomy, including the posterior vagina. "Terminologia Anatomica" has previously accepted 186 of these terms. Based on this literature review, we proposed the adoption of 11 new standardized anatomic terms, including 6 regional terms (anal sphincter complex, anorectum, genital-crural fold, interlabial sulcus, posterior vaginal compartment, and sacrospinous-coccygeus complex), 4 structural terms (greater vestibular duct, anal cushions, nerve to the levator ani, and labial fat pad), and 1 anatomic space (deep postanal space). In addition, the currently accepted term rectovaginal fascia or septum was identified as controversial and requires further research and definition before continued acceptance or rejection in medical communication. CONCLUSION: This study highlighted the variability in the anatomic nomenclature used in describing the posterior female pelvis and vulva. Therefore, we recommended the use of standardized terminology to improve communication and education across medical and anatomic disciplines.

Urethral function and failure: A review of current knowledge of urethral closure mechanisms, how they vary, and how they are affected by life events.

INTRODUCTION: A critical appraisal of the literature regarding female urethral function and dysfunction is needed in light of recent evidence showing the urethra's role in causing stress and urge urinary incontinence. METHODS: An evidence assessment was conducted using selected articles from the literature that contained mechanistic data on factors affecting urethral function and failure. RESULTS: Maximal urethral closure pressure (MUCP) is 40% lower in stress urinary incontinence (SUI) than normal controls. Evidence from five women shows relatively equal contributions to MUCP from striated/smooth muscle, vascular-plexus, connective tissue. MUCP varies twofold in individuals of similar age and declines 15% per decade even in nulliparous women. Age explains 57% of the variance in MUCP. This parallels with striated/smooth muscle loss and reduced nerve density. Factors influencing pressure variation minute-to-minute and decade-to-decade are poorly understood. Connective tissue changes have not been investigated. MUCP in de novo SUI persisting 9-months postpartum is 25% less than in age and parity-matched controls. Longitudinal studies do not show significant changes in urethral function after vaginal birth suggesting that changes in urethral support from birth may unmask pre-existing sphincter weakness and precipitate SUI. Mechanisms of interaction between support injury, pre-existing urethral weakness, and neuropathy are unclear. CONCLUSION: Urethral failure is the predominant cause of SUI and a contributing factor for UUI; potentially explaining why mixed symptoms predominate in epidemiological studies. Age-related striated muscle loss and differences between women of similar age are prominent features of poor urethral closure. Yet, connective tissue changes, vasculature function, and complex interactions among factors are poorly understood.