Pudendal nerve stretch during vaginal birth: a 3D computer simulation

Three-Dimensional Transperineal Ultrasound Assessment of the Anal Sphincter Immediately After Vaginal Birth: An Exploratory Study

OBJECTIVES

To assess the feasibility of acquiring adequate transperineal ultrasound (TPUS) volumes of the anal sphincter (AS) immediately after vaginal birth, the reproducibility of its measurements, and detecting defects therein.

METHODS

Secondary analysis of TPUS volumes of the AS, acquired immediately after vaginal birth with a transversely oriented convex probe. Two independent experts ranked off-line image quality as "inadequate," "adequate," or "ideal" using the Point-of-Care Ultrasound Image Quality scale. On "adequate" and "ideal" quality volumes, the length of the external AS at 6 and 12 o'clock, and the volume of the external and internal AS were measured. Additionally, volumes were screened for AS defects on tomographic ultrasound imaging. Subsequently, we rated the intra- and interrater agreement on those findings.

RESULTS

Of 183 volumes, 162 were considered "adequate" or of "ideal" quality (88.5%). Reasons for "inadequacy" were shadow artifacts (16/21), poor resolution (3/21), incomplete acquisition (1/21), or aberrant AS morphology (1/21). The intrarater reliability of two-dimensional (2D) and three-dimensional (3D) measurements was excellent, whereas interrater reliability was fair to good for 2D measurements and good for 3D measurements. In those tomographic ultrasound imaging (TUI) sequences including AS defects, the intra- and interrater reliability of the defect measurement were excellent [intraclass correlation coefficient (ICC) = 0.92 (0.80-0.94)] and moderate [ICC = 0.72 (0.63-0.79)]. In this cohort, there were only few (4/48; 8.3%) AS defects. However, grading them was poorly reproducible between experts.

CONCLUSION

TPUS of the AS immediately after vaginal birth yields adequate image quality and allows for reproducible measurements. In the few patients with AS defects, there was good agreement on the presence, but it was poor for the extent of defects.

De novo urethral hypermobility at 6 months after first delivery as a risk factor for stress urinary incontinence 12 years postpartum

OBJECTIVE

The aim of the study was to analyze the association between de novo urethral hypermobility 6 months postpartum and stress urinary incontinence (SUI) symptoms at 6 months and 12 years after first delivery. Risk factors associated with the development of postnatal urethral hypermobility were also examined.

METHODS

A longitudinal cohort study was conducted on primigravid women, after excluding those with UI before pregnancy and/or urethral hypermobility (rotational angle ≥30°) at term. At 6 months postpartum, SUI was assessed based on symptoms and introital ultrasound performed to measure rotational angle (difference between urethro-pelvic angle at rest and at maximum Valsalva). Twelve years after delivery, women were sent a questionnaire including SUI assessment and questions on parity, current age, and body mass index. Continuous variables were compared using student's t-test and qualitative variables using chi-squared tests. A logistic regression model was constructed including variables that reached statistical significance (P < 0.05) in the univariate analysis.

RESULTS

Of the 314 women who completed the 6-month follow-up, 265 (84.4%) were successfully contacted and completed the questionnaire at 12 years and these formed the study group. In 127 women (47.9%), de novo urethral hypermobility had developed by 6 months postpartum. There was no association between urethral hypermobility and SUI symptoms 6 months postpartum (OR: 1.17; 95% CI: 0.59-2.33). Twelve years after delivery, however, SUI was reported by 110 women overall (41.5%) and nearly half of the women who developed postnatal urethral hypermobility (61/127, 48.0%).

CONCLUSION

De novo urethral hypermobility 6 months postpartum constitutes a risk factor for SUI 12 years later.

Simulation of the Childbirth Process in LS-DYNA

Childbirth or labor, as the final phase of a pregnancy, is a biomechanical process that delivers the fetus from the uterus. It mainly involves two important biological structures in the mother, the uterus-generating the pushing force on the fetus-and the pelvis (bony pelvis and pelvic floor muscles)-resisting the movement of the fetus. The existing computational models developed in this field that simulate the childbirth process have focused on either the uterine expulsion force or the resistive structures of the pelvis, not both. An FEM model including both structures as a system was developed in this paper to simulate the fetus delivery process in LS-DYNA. Uterine active contraction was driven by contractile fiber elements using the Hill material model. The passive portion of the uterus and pelvic floor muscles were modeled with Neo Hookean and Mooney-Rivlin materials, respectively. The bony pelvis was modeled as a rigid body. The fetus was divided into three components: the head, neck, and body. Three uterine active contraction cycles were modeled. The model system was validated based on multiple outputs from the model, including the stress distribution within the uterus, the maximum Von Mises and principal stress on the pelvic floor muscles, the duration of the second stage of the labor, and the movement of the fetus. The developed model system can be applied to investigate the effects of pathomechanics related to labor, such as pelvic floor disorders and brachial plexus injury.

Impact of the Duration of the Second Stage of Labor on Postpartum Pelvic Floor Symptoms

IMPORTANCE

The associated effect of duration of the second stage of labor (SSL) on pelvic floor symptoms development is not well studied.

OBJECTIVE

This study aimed to examine the association between duration of SSL and pelvic floor symptoms at 6 months postpartum among primiparous women.

STUDY DESIGN

A planned secondary analysis of a multicenter randomized trial evaluating the impact of immediate versus delayed pushing on vaginal delivery rates, maternal morbidity, and neonatal outcomes was conducted between 2014 and 2018. For pelvic floor arm participants, demographic, pelvic examination, and validated questionnaire data were collected postpartum. Primary outcome was change in Pelvic Floor Distress Inventory 20 (PFDI-20) score from immediate to 6 months postpartum. Secondary outcomes included changes in the Pelvic Floor Impact Questionnaire, Fecal Incontinence Severity Index, Modified Manchester Health Questionnaire scores, and Pelvic Organ Prolapse Quantification measurements at 6 months postpartum. Participants were analyzed by SSL duration ≤60 minutes or >60 minutes.

RESULTS

Of the 2,414 trial participants, 767 (32%) completed pelvic floor assessments at 6 months. Pelvic Floor Distress Inventory 20 scores significantly improved at 6 months in the ≤60 minutes SSL group compared with >60 minutes SSL (-14.3 ± 48.0 and -3.2 ± 45.3, respectively; P = 0.04). Changes from immediate postpartum in total and subscale scores for other questionnaires at 6 months did not differ between groups. Prolapse stage did not differ between groups. Perineal body was significantly shorter in the >60 minutes SSL group (3.7 ± 0.7, 3.5 ± 0.8; P = 0.03).

CONCLUSIONS

Women with SSL >60 minutes experience less improvement in PFDI-20 scores at 6 months. Greater tissue and innervation trauma in those with SSL >60 minutes may explain persistently less improvement in PFDI-20 scores.

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.

Pudendal Neuralgia: Two case reports with laparoscopic nerve decompression

Pudendal neuralgia (PN) is a rare and underestimated condition. The reported incidence by the International Pudendal Neuropathy Association is 1/100000. However, the actual rate may be significantly higher, with a propensity for women. It is most frequently caused by an entrapment of the nerve at the level of the sacrospinous and sacrotuberous ligament, also known as pudendal nerve entrapment syndrome. Due to the late diagnosis and inadequate management, pudendal nerve entrapment syndrome often leads to considerable reduction in the quality of life and high health care costs. The diagnosis is made using Nantes Criteria, in conjunction with the patient's clinical history and physical findings. Clinical examination with an accurate assessment of the territory of the neuropathic pain is mandatory to set the therapeutic strategy. The aim of the treatment is to control the symptoms and it usually starts with conservative approaches which include analgesics, anticonvulsants, and muscle relaxants. Surgical nerve decompression can be proposed after failure of conservative management. The laparoscopic approach is a feasible and appropriate technique to explore and decompress the pudendal nerve, and to rule out other pelvic conditions that can cause similar symptomatology. In this paper, the clinical history of two patients affected by compressive PN is reported. Both patients underwent laparoscopic pudendal neurolysis suggesting that the treatment for PN should be individualised and carried out by a multidisciplinary team. When conservative treatment fails, laparoscopic nerve exploration and decompression is an adequate option to propose and should be performed by a trained surgeon.

Dorsal Root Ganglion Stimulation Therapy for Refractory Idiopathic Pudendal Neuralgia

Dorsal root ganglion stimulation is a relatively new treatment option for chronic pain conditions such as pudendal neuralgia, which is a chronic pain condition affecting the pudendal nerve in the pelvic region. Pudendal neuralgia is a debilitating condition that can significantly affect the patient's quality of life. In dorsal root ganglion stimulation, a small device is implanted that delivers electrical impulses to the dorsal root ganglion to modulate pain signals coming from the pudendal nerve. The procedure is considered investigational and has been investigated in case series and case reports with promising results. However, more research is needed to fully understand its safety and effectiveness. This case report highlights the potential of dorsal root ganglion stimulation as a treatment option for pudendal neuralgia and the need for further research to establish it as a standard treatment option.

The impact of pregnancy and childbirth on pelvic sensation: a prospective cohort study

Pelvic organ prolapse, urinary, bowel and sexual dysfunction, collectively called pelvic floor dysfunction (PFD) affects 1 in 3 women and has a significant public health impact. The causes of PFD are not fully understood but involve injury to connective tissue and motor nerve during childbirth. Women with PFD also have sensory nerve impairment, and it is likely this occurs during childbirth, but this has never been investigated. In the current study 150 women underwent quantitative sensory testing for vibration sensation at the vagina and clitoris, and stretch sensation at the vagina and introitus, in the third trimester, 3 and 6 months postnatal. Antenatally vibration sensation was reduced but stretch sensation was normal. Postnatally vibration sensation deteriorated whilst stretch sensation initially deteriorated but recovered by 6 months postnatal to antenatal levels (all p < 0.001). Mode of birth had a significant impact on sensation, with caesarean section appearing neuroprotective, normal vaginal birth resulted in a transient deterioration in sensation that recovered by 6 months, whilst assisted vaginal delivery was prolonged suggesting persistent neurological impairment (all p < 0.015). Further research is required to study the clinical effect of these changes on pelvic floor dysfunction in the medium and long-term.

A Computational Procedure to Derive the Curve of Carus for Childbirth Computational Modeling

Computational modeling serves an important role in childbirth-related research. Prescribed fetal descent trajectory is a key characteristic in childbirth simulations. Two major types of fully prescribed fetal descent trajectory can be identified in the literature: straight descent trajectories and curve of Carus. The straight descent trajectory has the advantage of being simpler and could serve as a reasonable approximation for relatively small fetal movements during labor, but it cannot be used to simulate the entire childbirth process. Curve of Carus is the well-recognized fetal descent trajectory with physiological significance. However, no mathematical description of the curve of Carus can be found in the existing computational studies. This status of curve of Carus simulation in the literature hinders the direct comparison of results across different studies and the advancement of computational techniques built upon previous research. The goals of this study are: (1) propose a universal approach to achieve the curve of Carus for the second stage of labor, from the point when the fetal head engages the pelvis to the point when the fetal head is fully delivered. (2) demonstrate its utility when considering various fetal head sizes. The current study provides a detailed formulation of the curve of Carus, considering geometries of both the mother and the fetus. The maternal geometries were obtained from MRI data, and the fetal head geometries were based on laser scanning of a replica of a real fetal head.

Transvaginal pudendal nerve blocks in patients with pudendal neuralgia: 2-year follow-up results

PURPOSE

Pudendal neuralgia (PN) is an extremely painful neuropathy of the pudendal nerve resulting in a negative impact on a patient's quality of life. The aim of this study is to evaluate the 2-year outcomes of repetitive doses of the transvaginal pudendal nerve injections (PNI), and to compare the success of the PNI concerning anatomical levels (endopelvic and extrapelvic portion) of the pudendal nerve pathology.

METHODS

This retrospective longitudinal cohort study consists of patients with PN diagnosed with the first four essential Nantes criteria. Diagnostic PNI was performed on 67 patients to fulfill the fifth criteria of Nantes. A total of 56 patients who responded to the initial diagnostic PNI underwent therapeutic repeated transvaginal PNIs twice for 3 weeks apart. Mean pain intensity scores were measured using a visual analog scale at the 1st, 3rd, 6th, 12th, and 24th months after the therapeutic blocks were completed. Effectiveness of the PNIs' was defined as ≥ 50% improvement of the initial pain, and relative improvement was defined as 30-50% improvement of the initial pain. Treatment failure was defined as the reduction of the initial pain by less than 30% or the return of the pain to its worst condition.

RESULTS

The efficacy of the PNIs significantly declined over time. Pudendal nerve blocks provided a significant decrease in pain scores; however, this decrease lost its strength significantly in the 24th month. The intervention was more effective in entrapments of the pudendal nerve between sacrospinous and sacrotuberous ligaments or below (Level-2) when compared to the injuries in the endopelvic part (Level-1). More than 50% pain reduction continued in five patients with pathology at Level-1 and 24 patients with pathology at Level-2.

CONCLUSION

Repeated PNIs could provide a significant decrease in pain scores for both short- and long-term periods. However, the efficacy of the PNIs declined over 2 years. The success of PNIs may be affected by the anatomical level of the nerve injury; therefore, interligamentous pudendal nerve entrapment cases have more benefits than the cases of pudendal nerve entrapment in the endopelvic part. However, it is recommended to perform therapeutic nerve blocks even in patients with suspected endopelvic pudendal nerve pathology before the referral to surgery.

Development of a Novel, Low-Cost, Low-Fidelity Simulation Model for Pudendal Nerve Block Application

BACKGROUND

Pudendal nerve block is an important alternative to neuraxial anesthesia, yet studies demonstrate that 3% to 50% of pudendal nerve blocks are ineffective. Lack of clinician training is the most common cause, and there are no simulation models currently described.

OBJECTIVE

To develop and test a novel, low-cost, low-fidelity simulation model for training residents in the placement of a pudendal nerve block.

METHODS

A pudendal nerve block model was developed using commonly found supplies, with a cost of $20.57. First-year to fourth-year obstetrics and gynecology (OB/GYN) and family medicine (FM) residents were invited to 1 of 4 pudendal nerve block 1-hour simulation sessions from December 2019 to March 2021 during their required teaching sessions. Expert faculty led a discussion of pudendal nerve blocks, then participants practiced with the described model. A survey about the model was created by the authors and administrated prior to and immediately after the session. Pre- and post-surveys were analyzed by Wilcoxon signed rank tests, and Bonferroni correction was performed.

RESULTS

Thirty-four out of a total of 36 eligible residents participated (94%). Residents showed improvement in knowledge (median pre-simulation score 43.99 compared with 70.06 post-simulation, P<.00625) and self-assessed confidence (median pre-simulation score 1.7 compared with 3.2 post-simulation, P<.00625) of a pudendal block placement after simulation training.

CONCLUSIONS

This new, low-cost, reusable, low-fidelity simulation model for pudendal nerve block placement improved knowledge and confidence in OB/GYN and FM residents after 1 hour of simulation training.

Dyssynergic Defecation and Other Evacuation Disorders

Constipated patients are frequently referred to gastroenterologists for symptoms refractory to lifestyle modifications and laxatives. Dyssynergic defecation, the dyscoordination of rectoanal, abdominal, and pelvic floor muscles to facilitate defecation, is a major cause of refractory primary constipation. Understanding of the diagnosis, evaluation, and management of dyssynergic defecation and other evacuation disorders will allow providers to effectively manage these patients. This review focuses on the definition, pathophysiology, evaluation, and treatment of dyssynergic defecation and other evacuation disorders. Emerging treatments for these disorders include home biofeedback therapy for dyssynergic defecation and translumbosacral neuromodulation therapy for levator ani syndrome.

Protective effect and potential mechanism of Schwann cell-derived exosomes on mechanical damage of rat dorsal root ganglion cells

BACKGROUND

Pudendal nerve (PN) injury was one of the most important pathogenesis of stress urinary incontinence (SUI). Schwann cell (SC)-derived exosomes could promote axonal regeneration. Wnt protein could significantly promote axonal regeneration and participate in the regulation of proliferation and differentiation of neural stem cells. Therefore, we sought to determine whether SCs-derived exosomes might also protect against damaged dorsal root ganglion cells (DRGs) through the Wnt/β-catenin pathway.

MATERIAL AND METHODS

The DRGs injury model was fabricated using a four-point bending system. The exosomes were separated from the SCs supernatant. XAV939, which was a small molecule inhibitor, was used to inhibit the Wnt/β-catenin pathway. Next, Cell Counting Kit-8 (CCK8) kit was used to detect cell activity. We evaluated the proliferative activity of DRG cells using the cell cycle and apoptosis detection kit. We assessed the cell apoptotic rates through the Annexin V/PE double staining. Finally, we detect the expression of downstream proteins of Wnt/β-catenin pathway in DRG cells using western blotting.

RESULTS

SC-derived exosomes had protective effects on DRGs after mechanical damage, which could promote cell proliferation, transition of the cell cycle to the G2 phase, and inhibit cell apoptosis. Exogenous administration of XAV939 suppressed the promoting effect of SCs -derived exosomes on DRG cells and the expression of downstream proteins of Wnt/β-catenin pathway in DRG cells was also suppressed.

CONCLUSION

These results suggested that SC-derived exosomes have a repairing effect on DRG cells injury caused by cyclic mechanical stretching (CMS) and the Wnt/β-catenin pathway is potentially involved in the process.

Levator plate descent angle in pelvic floor disorders

BACKGROUND

The levator plate descent angle (LPDA) quantifies the levator plate position with reference to the pubic bone and perineal body at rest. Unfortunately, research on this notable new parameter is lacking, but it is clear that levator ani deficiency (LAD) will undermine the fundamental role of the levator ani muscle (LAM) in organ support. The aim of this study was to establish the relationship between the LPDA and LAD in patients with pelvic floor disorders.

METHODS

This retrospective study was conducted at Seoul Songdo Hospital, Korea between August 2019 and August 2020 on women with symptoms of pelvic floor disorder such as urinary incontinence, constipation, and fecal incontinence. In all cases, three-dimensional pelvic floor ultrasound was performed for LAD scoring, minimal levator hiatus, and LPDA evaluation. We evaluated LAD using a scoring system that graded levator injury according to the insertion point of each subdivision scored unilaterally. For the entire LAM group, a cumulative LAD score that ranged between 0 and 18 was possible. Scores were categorized as mild (0-6 points), moderate (7-12 points), and severe (13-18 points) deficiency RESULTS: A total of 93 patients were included in the study (mean age 65.89 ± 11.12 [range, 34-86] years). Thirteen participants had mild LAD scores (14.0%), 42 had moderate LAD scores (45.2%), and 38 had severe LAD scores (40.9%). There was a significant difference in mean age (59.23 ± 12.55 years vs. 64.43 ± 10.03 vs. 69.79 ± 10.55 years, p = 0.005) and mean parity (1.85 ± 0.90 vs 2.48 ± 1.15 vs 2.76 ± 1.10, p = 0.038) of patients between groups. There was also a significant difference in the mean Wexner incontinence score (7.14 ± 3.63 vs 7.24 ± 5.76 vs 11.41 ± 5.54, p = 0.028) and in the mean fecal incontinence quality of life (FIQOL) score (12.91 ± 3.11 vs 14.10 ± 3.87 vs 10.41 ± 3.65, p = 0.014). The mean value of the LPDA in the group with mild LAD scores was 14.65° (SD ± 3.54) and in the group with moderate LAD scores was 9.66° (SD ± 3.36). In the group with severe LAD scores, the mean LPDA was 1.83° (SD ± 4.71). The mean value for minimal levator hiatus (MLH) area in the mild LAD score group was 14.16cm² (SD ± 2.72), that in the moderate LAD score group was 15.82cm² (SD ± 2.30), and that in the severe LAD score group was 17.99cm² (SD ± 2.81). There were significant differences between the three groups both in decreasing LPDA (p < 0.001) and increasing MLH (p < 0.001). There was a negative correlation between the LAD score and LPDA and the Pearson correlation coefficient was -0.528 (moderate correlation). There was a positive correlation between the LAD score and MLH, and the Pearson correlation coefficient was 0.303 (weak correlation).

CONCLUSIONS

The LAD score and LPDA have a moderate negative correlation. In patients with severe pelvic floor symptoms and extensive LAM injury, high LAD scores and low LPDA results were confirmed. In the treatment of patients with pelvic floor disorders, the LPDA seems to be a very useful parameter in determining the severity of structural defects.

Sexual dysfunction due to pudendal neuralgia: a systematic review

Background

The pudendal nerve is considered as the main nerve of sexuality. Pudendal neuralgia is an underdiagnosed disease in clinical practice. The aim of this systematic review is to highlight the role of pudendal neuralgia on sexual dysfunction in both sexes.

Methods

A PubMed search was performed using the following keywords: “Pudendal” AND “Sexual dysfunction” or “Erectile dysfunction” or “Ejaculation” or “Persistent sexual arousal” or “Dyspareunia” or “Vulvodynia”. The search involved patients having sexual dysfunction due to pudendal neuralgia. Treatment received was also reported.

Results

Five case series, seven cohort studies, two pilot studies, and three randomized clinical trials were included in this systematic review. Pudendal nerve and/or artery entrapment, or pudendal neuralgia, is a reversible cause of multiple sexual dysfunctions. Interventions such as anesthetic injections, neurolysis, and decompression are reported as potential treatment modalities. There are no studies describing the role of pudendal canal syndrome in the pathophysiology or treatment of delayed ejaculation or penile shortening.

Discussion

Pudendal neuralgia is an underestimated yet important cause of persistent genital arousal, erectile dysfunction (ED), premature ejaculation (PE), ejaculation pain, and vulvodynia. Physicians should be aware of this entity and examine the pudendal canal in such patients before concluding an idiopathic cause of sexual dysfunction.

Targeted neuromodulation of pelvic floor nerves in aging and multiparous rabbits improves continence

Pelvic floor muscle stretch injury during pregnancy and birth is associated with the incidence of stress urinary incontinence (SUI), a condition that affects 30-60% of the female population and is characterized by involuntary urine leakage during physical activity, further exacerbated by aging. Aging and multiparous rabbits suffer pelvic nerve and muscle damage, resulting in alterations in pelvic floor muscular contraction and low urethral pressure, resembling SUI. However, the extent of nerve injury is not fully understood. Here, we used electron microscopy analysis of pelvic and perineal nerves in multiparous rabbits to describe the extent of stretch nerve injury based on axon count, axon size, myelin-to-axon ratio, and elliptical ratio. Compared to young nulliparous controls, mid-age multiparous animals showed an increase in the density of unmyelinated axons and in myelin thickness in both nerves, albeit more significant in the bulbospongiosus nerve. This revealed a partial but sustained damage to these nerves, and the presence of some regenerated axons. Additionally, we tested whether electrical stimulation of the bulbospongiosus nerve would induce muscle contraction and urethral closure. Using a miniature wireless stimulator implanted on this perineal nerve in young nulliparous and middle age multiparous female rabbits, we confirmed that these partially damaged nerves can be acutely depolarized, either at low (2-5 Hz) or medium (10-20 Hz) frequencies, to induce a proportional increase in urethral pressure. Evaluation of micturition volume in the mid-age multiparous animals after perineal nerve stimulation, effectively reversed a baseline deficit, increasing it 2-fold (p = 0.02). These results support the notion that selective neuromodulation of pelvic floor muscles might serve as a potential treatment for SUI.

Childbirth Computational Models: Characteristics and Applications

The biomechanical process of childbirth is necessary to usher in new lives-but it can also result in trauma. This physically intense process can put both the mother and the child at risk of injuries and complications that have life-long impact. Computational models, as a powerful tool to simulate and explore complex phenomena, have been used to improve our understanding of childbirth processes and related injuries since the 1990s. The goal of this paper is to review and summarize the breadth and current state of the computational models of childbirth in the literature-focusing on those that investigate the mechanical process and effects. We first summarize the state of critical characteristics that have been included in computational models of childbirth (i.e., maternal anatomy, fetal anatomy, cardinal movements, and maternal soft tissue mechanical behavior). We then delve into the findings of the past studies of birth processes and mechanical injuries in an effort to bridge the gap between the theoretical, numerical assessment and the empirical, clinical observations and practices. These findings are from applications of childbirth computational models in four areas: (1) the process of childbirth itself, (2) maternal injuries, (3) fetal injuries, and (4) protective measures employed by clinicians during delivery. Finally, we identify some of the challenges that computational models still face and suggest future directions through which more biofidelic simulations of childbirth might be achieved, with the goal that advancing models may provide more efficient and accurate, patient-specific assessment to support future clinical decision-making.

Peripartum pelvic floor disorder clinics inform obstetric provider practices

INTRODUCTION AND HYPOTHESIS

The objective of this study is to evaluate obstetric providers' knowledge and practice patterns since the establishment of a peripartum pelvic floor disorder clinic.

METHODS

This is a prospective, cross-sectional survey study of obstetric providers at an academic tertiary care health system. A 22-question survey was designed to collect provider demographic data, indications for and barriers to referrals, provider satisfaction, and impact of the clinic's existence on peripartum pelvic floor dysfunction diagnosis and management. Eligibility criteria included obstetrics and gynecology trainees, attending physicians, certified nurse midwives, and advanced practice providers.

RESULTS

There were 86 survey responses yielding a response rate of 72.1%. The majority of respondents were staff obstetricians (57.0%) or trainees (26.7%). Most commonly reported referral indications were third- and fourth-degree lacerations (94.9%), complex lacerations (70.5%), wound breakdown (57.7%), and urinary retention (53.8%). Regarding satisfaction with the peripartum pelvic floor disorder clinic, of referring providers, 77 (98.7%) agreed or strongly agreed that evaluations were useful for patients and 78 (100%) agreed or strongly agreed that evaluations were useful for themselves. Seventy-six (97.4%) respondents reported that they were very satisfied with the peripartum pelvic floor disorder clinic overall. The majority of respondents agreed or strongly agreed that the clinic increased their awareness of both obstetric anal sphincter injuries and their impact on maternal health (84.6%).

CONCLUSION

The introduction of a peripartum pelvic floor disorder clinic results in high obstetric provider satisfaction and positively impacts patient care through increased provider knowledge and awareness on the management of obstetric anal sphincter injuries.

Factors involved in the persistence of stress urinary incontinence from postpartum to 12 years after first delivery

AIMS

The aim of this study was to investigate constitutional-, pregnancy-, labor-, and delivery-related factors involved in the long-term persistence of stress urinary incontinence (SUI) from 6 months postpartum to 12 years after first delivery. We also evaluated severity and impact on quality of life of persistent SUI.

METHODS

This was a longitudinal study including primigravid women who gave birth at our Public Health Hospital during 2007. Urinary symptoms were investigated at inclusion, 6 months and 12 years after delivery. Persistent SUI was defined as SUI reported both at 6 months postpartum and 12 years after first delivery. The International Consultation on Incontinence-Urinary Incontinence-Short Form (ICIQ-UI-SF) and the Incontinence Severity Index (ISI) were used to evaluate SUI.

RESULTS

During the inclusion period, 479 pregnant women were interviewed, 381 attended the 6-month follow-up visit, and 315 formed the study group. SUI persisted in 36 out of 44 (81.8%) women. With the ISI, 52.8% of these women were categorized as having slight, 41.7% moderate, and 5.6% severe incontinence. The mean ICIQ-UI-SF score was 7.13 (SD 3.51). Pregnancy SUI (odds ratio [OR], 4.54; 95% confidence interval [CI], 2.10-9.80) and active second stage of labor more than or equal to 1 hour (OR, 3.68; 95% CI, 1.21-11.14) were independently associated with persistent SUI.

CONCLUSIONS

Women who reported SUI during pregnancy, and those who had pushed for more than or equal to 1 hour in the second stage of labor were at greater risk of SUI persisting from 6 months postpartum to long after delivery. We found this independent association after controlling for several constitutional-, pregnancy-, labor-, and delivery-related variables.

Effects of electrical stimulation on cell activity, cell cycle, cell apoptosis and β‑catenin pathway in the injured dorsal root ganglion cell

The present study aimed to investigate the effects of electrical stimulation (ES) on cell activity, cell cycle and apoptosis in injured rat dorsal root ganglion (DRG) cells induced by cyclic mechanical stretching (CMS). The present study also investigated whether the Wnt/β‑catenin pathway is involved in this process. Injury and ES models were established in DRG cells. Then, cell activity was detected using a Cell Counting Kit‑8 and 5‑ethynyl‑2'‑deoxyuridine‑594 cell proliferation assay kit. Cell cycle distribution was detected using a cell cycle detection kit. Apoptosis was detected using an Annexin V‑FITC apoptosis detection kit, and Wnt/β‑catenin pathway‑associated proteins were detected using western blotting. The present study demonstrated that CMS decreased DRG cell activity, increased the number of cells in the S phase, promoted cell apoptosis and inhibited the Wnt/β‑catenin pathway. In addition, ES significantly increased the proliferation activity of DRG cells, increased the number of cells in the G2 phase, decreased the apoptotic rate and activated the Wnt/β‑catenin pathway, ultimately reversing the injury caused by CMS. Following inhibition of the Wnt/β‑catenin signaling pathway using XAV939, the effects of ES were weakened. In conclusion, the present study demonstrated that ES may reverse CMS‑induced injury in DRG cells, and that the Wnt signaling pathway may be involved in this process.

Biomechanical comparison of Thiel embalmed and fresh frozen nerve tissue

The aim of this study was to determine the effect of Thiel embalming on the biomechanical properties of nerve tissue, to validate the use of Thiel embalmed bodies as a reliable model system for obtaining biomechanical data to supplement neurodynamic models, for anesthesiological and neurosurgical training and for future preclinical test set-ups involving nerve tissue. Upon the arrival of a body at the anatomy department, a fresh median nerve was harvested, the harvest site was sutured and following the Thiel embalming procedure the Thiel embalmed median nerve of the opposing wrist was harvested. Micro CT was performed to establish the cross-sectional area and biomechanical tensile testing was performed to compare the Young's modulus/elasticity of fresh frozen and Thiel embalmed nerves. Thiel embalming did not cause a significant difference in elasticity when comparing Thiel embalmed and fresh frozen specimens. A correlation was found between the cross-sectional area of Thiel embalmed nerve specimens and their Young's modulus. Thiel embalming does not significantly alter the elasticity of nerve tissue compared to fresh frozen nerve tissue. Similar shapes were observed when comparing the stress/strain curves of both specimen types. This indicates that Thiel embalmed nerve tissue is a viable alternative for using fresh frozen specimens when investigating biomechanical principles/mechanisms. Some specimens showed a reversed trend in Young's modulus that could be related to slight differences in embalming outcome, so caution is advised when Thiel embalmed specimens are used to obtain raw numerical data for direct application in the clinic.

Simulated vaginal delivery causes transients vaginal smooth muscle hypersensitivity and urethral sphincter dysfunction

BACKGROUND

Although pelvic floor dysfunction (PFD) has a multifactorial etiology, pregnancy and childbirth are considered crucial events predisposing to urinary incontinence as well as pelvic organ prolapse, which are highly prevalent. Rats are the most frequently used animal model and pudendal nerve crush (PNC) and vaginal distension (VD) are often used to mimic vaginal delivery.

OBJECTIVE

To document the time course of events after simulated vaginal delivery (SVD) on the urethral sphincter and the vaginal smooth muscle layer.

MATERIALS AND METHODS

Virgin female Sprague-Dawley rats were subjected to SVD (PNC + VD) or sham surgery and evaluated at 7, 14, 21, and 42 days after the injury. Urethral function was determined in vivo by microultrasound during cystometry and vaginal smooth muscle layer was harvested for in vitro pharmacologic investigation by isometric tension recording. Furthermore, vaginal and urethral samples were investigated by immunohistochemistry and real-time quantitative polymerase chain reaction.

RESULTS

Microultrasound showed no bursting of the urethral sphincter in the SVD group at 7 days with a functional recovery starting at 14 days, and normal bursting at 21 and 42 days. Vaginal smooth muscle showed higher sensitivity to carbachol at 14 and 21 days after injury; however, at 42 days, its sensitivity decreased when compared with sham.

CONCLUSION

SVD induces urethral dysfunction and a shift in vaginal smooth muscle contractile responses to carbachol.

Postpartum perineal pain: may the vaginal treatment with CO2 laser play a key-role in this challenging issue?

PURPOSE

Pregnancy and childbirth, despite being physiological events, represent a very delicate period in a woman's life, because they expose to important vulvo-perineal traumas. The pelvic pain that follows each delivery, whether spontaneous or surgical (caesarean section), does not end in the first days after birth but, depending on the studies, becomes persistent in a very variable percentage of cases. Therefore, in the present pilot study, we aimed, for the first time in literature, to assess the efficacy of CO₂ laser in women affected by perineal postpartum symptoms.

MATERIALS AND METHODS

Between February 2013 and June 2018, all women with late postpartum pelvic pain referred to the Department of Obstetrics and Gynecology of San Marino Hospital, were recruited and treated using the CO₂ laser for three applications every 4-6 weeks.

RESULTS

Between February 2013 and June 2018, according to the inclusion and exclusion criteria, 32 women with late postpartum pelvic pain were recruited in our protocol study. Mean age of patients was 34.1 years. At latest follow-up, our data demonstrated an improvement in symptoms (dyspareunia, pain at introitus, vaginal dryness, itching and vaginal burning) with a mean reduction of this symptom of 70% from baseline.

CONCLUSIONS

This study has shown the effectiveness of CO₂ laser treatment in postpartum perineal pain. Nevertheless, our results should be considered promising but preliminary. In fact, they need to be tested in larger cohort of patients to confirm its application in clinical practice and to evaluate the long-term duration of this treatment.

Persistent occiput posterior position and stress distribution in levator ani muscle during vaginal delivery computed by a finite element model

INTRODUCTION AND HYPOTHESIS

Objective of this study was to develop an MRI-based finite element model and simulate a childbirth considering the fetal head position in a persistent occiput posterior position.

METHODS

The model involves the pelvis, fetal head and soft tissues including the levator ani and obturator muscles simulated by the hyperelastic nonlinear Ogden material model. The uniaxial test was measured using pig samples of the levator to determine the material constants. Vaginal deliveries considering two positions of the fetal head were simulated: persistent occiput posterior position and uncomplicated occiput anterior position. The von Mises stress distribution was analyzed.

RESULTS

The material constants of the hyperelastic Ogden model were measured for the samples of pig levator ani. The mean values of Ogden parameters were calculated as: μ1 = 8.2 ± 8.9 GPa; μ2 = 21.6 ± 17.3 GPa; α1 = 0.1803 ± 0.1299; α2 = 15.112 ± 3.1704. The results show the significant increase of the von Mises stress in the levator muscle for the case of a persistent occiput posterior position. For the optimal head position, the maximum stress was found in the anteromedial levator portion at station +8 (mean: 44.53 MPa). For the persistent occiput posterior position, the maximum was detected in the distal posteromedial levator portion at station +6 (mean: 120.28 MPa).

CONCLUSIONS

The fetal head position during vaginal delivery significantly affects the stress distribution in the levator muscle. Considering the persistent occiput posterior position, the stress increases evenly 3.6 times compared with the optimal head position.

Electrical stimulation of the pudendal nerve promotes neuroregeneration and functional recovery from stress urinary incontinence in a rat model

The pudendal nerve can be injured during vaginal delivery of children, and slowed pudendal nerve regeneration has been correlated with development of stress urinary incontinence (SUI). Simultaneous injury to the pudendal nerve and its target muscle, the external urethral sphincter (EUS), during delivery likely leads to slowed neuroregeneration. The goal of this study was to determine if repeat electrical stimulation of the pudendal nerve improves SUI recovery and promotes neuroregeneration in a dual muscle and nerve injury rat model of SUI. Rats received electrical stimulation or sham stimulation of the pudendal nerve twice weekly for up to 2 wk after injury. A separate cohort of rats received sham injury and sham stimulation. Expression of brain-derived neurotrophic factor (BDNF) and β_II-tubulin expression in Onuf's nucleus were measured 2, 7, and 14 days after injury. Urodynamics, leak point pressure (LPP), and EUS electromyography (EMG) were recorded 14 days after injury. Electrical stimulation significantly increased expression of BDNF at all time points and β_II-tubulin 1 and 2 wk after injury. Two weeks after injury, LPP and EUS EMG during voiding and LPP testing were significantly decreased compared with sham-injured animals. Electrical stimulation significantly increased EUS activity during voiding, although LPP did not fully recover. Repeat pudendal nerve stimulation promotes neuromuscular continence mechanism recovery possibly via a neuroregenerative response through BDNF upregulation in the pudendal motoneurons in this model of SUI. Electrical stimulation of the pudendal nerve may therefore improve recovery after childbirth and ameliorate symptoms of SUI by promoting neuroregeneration after injury.

Risk factors for postpartum urinary retention after vaginal delivery at term without epidural anesthesia

Objective: We performed a retrospective case-control study of vaginal delivery at term without epidural anesthesia to identify clinical predictions of postpartum urinary retention (PUR). Methods: We reviewed the obstetric records of all singleton vaginal deliveries at Japanese Red Cross, Katsushika Maternity Hospital form January 2016 through December 2017. Results: There were 58 women (2.4%) complicated by PUR and 2391 women without PUR. A multivariate analysis revealed nulliparity, instrumental delivery, and episiotomy as independent risk factors for PUR (nulliparity: adjusted OR 2.39, 95%CI 1.2-4.8, p = 0.01; instrumental delivery: 3.53, 95%CI 1.9-6.7, p < .01, episiotomy: adjusted OR 1.96, 95%CI 1.0-3.8, p = .04). While, urination (or urethral catheterization) within 1 hour before delivery revealed as independent prevention factor for PUR (adjusted OR 0.54, 95%CI 0.30-0.99, p = .048). Conclusions: The risk factors identified in our institute seemed to approximately similar to those observed in the institutes capable of performing epidural anesthesia. In addition, urination just before delivery seemed to be an independent prevention factor for PUR.

Muscle function of the pelvic floor in healthy, puerperal women with pelvic floor dysfunction

OBJECTIVES

To understand the function of the pelvic floor muscles (PFM) at different ages in healthy women and in puerperal women with pelvic floor dysfunctions (PFD) and to ascertain whether there are differences among them.

MATERIAL AND METHODS

A descriptive cross-sectional study was conducted between June 2014 and September 2016 and included 177 women, 70 of whom had no symptoms of PFD, 53 primiparous mothers in late postpartum and 54 with PFD. The function of the PFM was measured through vaginal palpation (quality of the contraction); manometry (force); dynamometer (tone, strength, and response to stretching), and surface electromyography (neuromuscular activity and resistance).

RESULTS

The healthy women showed superior values for PFM tone, maximum strength, neuromuscular activity and resistance than the puerperal mothers and the women with PFD (P<.01). The puerperal women and those with PFD showed similar functional PFM values (P>.05). The muscle function of the healthy women did not vary significantly with age, except in the case of tone, which was lower in the women older than 46 years (P=.004).

CONCLUSIONS

Age and births decrease the baseline tone of the PFM in healthy women. Therefore, lower strength, resistance and neuromuscular activity appear to be the main difference between the PFM of women with PFD and the PFM of healthy women.

Cell-based secondary prevention of childbirth-induced pelvic floor trauma

With advancing population age, pelvic-floor dysfunction (PFD) will affect an increasing number of women. Many of these women wish to maintain active lifestyles, indicating an urgent need for effective strategies to treat or, preferably, prevent the occurrence of PFD. Childbirth and pregnancy have both long been recognized as crucial contributing factors in the pathophysiology of PFD. Vaginal delivery of a child is a serious traumatic event, causing anatomical and functional changes in the pelvic floor. Similar changes to those experienced during childbirth can be found in symptomatic women, often many years after delivery. Thus, women with such PFD symptoms might have incompletely recovered from the trauma caused by vaginal delivery. This hypothesis creates the possibility that preventive measures can be initiated around the time of delivery. Secondary prevention has been shown to be beneficial in patients with many other chronic conditions. The current general consensus is that clinicians should aim to minimize the extent of damage during delivery, and aim to optimize healing processes after delivery, therefore preventing later dysfunction. A substantial amount of research investigating the potential of stem-cell injections as a therapeutic strategy for achieving this purpose is currently ongoing. Data from small animal models have demonstrated positive effects of mesenchymal stem-cell injections on the healing process following simulated vaginal birth injury.

The Epidemiology of Pelvic Floor Disorders and Childbirth: An Update

Using a lifespan model, this article presents new scientific findings regarding risk factors for pelvic floor disorders (PFDs), focusing on the role of childbirth in the development of single or multiple coexisting PFDs. Phase I of the model includes predisposing factors, such as genetic predisposition and race. Phase II includes inciting factors, such as obstetric events. Prolapse, urinary incontinence (UI), and fecal incontinence (FI) are more common among vaginally parous women, although the impact of vaginal delivery on risk of FI is less dramatic than prolapse and UI. Phase III includes intervening factors, such as age and obesity.

Finite element model focused on stress distribution in the levator ani muscle during vaginal delivery

Introduction and hypothesis

During vaginal delivery, the levator ani muscle (LAM) undergoes severe deformation. This stress can lead to stretch-related LAM injuries. The objective of this study was to develop a sophisticated MRI-based model to simulate changes in the LAM during vaginal delivery.

Methods

A 3D finite element model of the female pelvic floor and fetal head was developed. The model geometry was based on MRI data from a nulliparous woman and 1-day-old neonate. Material parameters were estimated using uniaxial test data from the literature and by least-square minimization method. The boundary conditions reflected all anatomical constraints and supports. A simulation of vaginal delivery with regard to the cardinal movements of labor was then performed.

Results

The mean stress values in the iliococcygeus portion of the LAM during fetal head extension were 4.91–7.93 MPa. The highest stress values were induced in the pubovisceral and puborectal LAM portions (mean 27.46 MPa) at the outset of fetal head extension. The last LAM subdivision engaged in the changes in stress was the posteromedial section of the puborectal muscle. The mean stress values were 16.89 MPa at the end of fetal head extension. The LAM was elongated by nearly 2.5 times from its initial resting position.

Conclusions

The cardinal movements of labor significantly affect the subsequent heterogeneous stress distribution in the LAM. The absolute stress values were highest in portions of the muscle that arise from the pubic bone. These areas are at the highest risk for muscle injuries with long-term complications.

Neuroanatomic and behavioral correlates of urinary dysfunction induced by vaginal distension in rats

The aim of the present study was to use a model of simulated human childbirth in rats to determine the damage to genitourinary structures and behavioral signs of urinary dysfunction induced by vaginal distension (VD) in female rats. In experiment 1, the length of the genitourinary tract and the nerves associated with it were measured immediately after simulated human delivery induced by VD or sham (SH) procedures. Electroneurograms of the dorsal nerve of the clitoris (DNC) were also recorded. In experiment 2, histological characteristics of the bladder and major pelvic ganglion of VD and SH rats were evaluated. In experiment 3, urinary parameters were determined in conscious animals during 6 h of dark and 6 h of light before and 3 days after VD or SH procedures. VD significantly increased distal vagina width (P < 0.001) and the length of the motor branch of the sacral plexus (P < 0.05), DNC (P < 0.05), and vesical nerves (P < 0.01) and decreased DNC frequency and amplitude of firing. VD occluded the pelvic urethra, inducing urinary retention, hematomas in the bladder, and thinness of the epithelial (P < 0.05) and detrusor (P < 0.01) layers of the bladder. Major pelvic ganglion parameters were not modified after VD. Rats dripped urine in unusual places to void, without the stereotyped behavior of micturition after VD. The neuroanatomic injuries after VD occur alongside behavioral signs of urinary incontinence as determined by a new behavioral tool for assessing micturition in conscious animals.

Pelvic floor dysfunction and sensory impairment: Current evidence

AIMS

To explore the role of sensory nerve impairment in women with pelvic organ prolapse, painful bladder syndrome, urinary and fecal incontinence, and sexual dysfunction.

METHODS

Medline and Embase were searched for articles in which sensory testing, either quantitative sensory testing or current perception thresholds, had been used to evaluate women with pelvic organ prolapse, stress and urge urinary incontinence, fecal incontinence and female sexual dysfunction. All search terms were expanded within each database prior to searching.

RESULTS

Research to date has included small numbers of participants, used poorly matched controls, lacked a systemic sensory examination and applied non-standardized sensory testing techniques. However, the evidence suggests women with pelvic organ prolapse demonstrate sensory dysfunction. The role of sensory impairment in stress urinary incontinence is inconclusive. In women with urge urinary incontinence there is some evidence to suggest it may be urethrally mediated. Women with painful bladder syndrome may have more sensitive nerve endings which are unable to ignore repeated stimuli. Sensory impairment is common in women with sexual dysfunction, typically involving larger nerve fibres. There were no studies evaluating sensory function in women with fecal incontinence.

CONCLUSION

Current evidence suggests women with pelvic floor dysfunction demonstrate sensory impairment though the causes remain unclear. Further studies are needed to investigate the different conditions of pelvic floor dysfunction using standardized sensory testing techniques, as well as evaluate the timing and mechanism by which any sensory impairment develops. Neurourol. Urodynam. 36:550-556, 2017. © 2016 Wiley Periodicals, Inc.

Biomechanical properties of synthetic surgical meshes for pelvic prolapse repair

Synthetic meshes are widely used for surgical repair of different kind of prolapses. In the light of the experience of abdominal wall repair, similar prostheses are currently used in the pelvic region, to restore physiological anatomy after organ prolapse into the vaginal wall, that represent a recurrent dysfunction. For this purpose, synthetic meshes are surgically positioned in contact with the anterior and/or posterior vaginal wall, to inferiorly support prolapsed organs. Nonetheless, while mesh implantation restores physiological anatomy, it is often associated with different complications in the vaginal region. These potentially dangerous effects induce the surgical community to reconsider the safety and efficacy of mesh transvaginal placement. For this purpose, the evaluation of state-of-the-art research may provide the basis for a comprehensive analysis of mesh compatibility and functionality. The aim of this work is to review synthetic surgical meshes for pelvic organs prolapse repair, taking into account the mechanics of mesh material and structure, and to relate them with pelvic and vaginal tissue biomechanics. Synthetic meshes are currently available in different chemical composition, fiber and textile conformations. Material and structural properties are key factors in determining mesh biochemical and mechanical compatibility in vivo. The most significant results on vaginal tissue and surgical meshes mechanical characterization are here reported and discussed. Moreover, computational models of the pelvic region, which could support the surgeon in the evaluation of mesh performances in physiological conditions, are recalled.

The Effect of Traction Force and Hip Abduction Angle on Pudendal Nerve Compression in Hip Arthroscopy: A Cadaveric Model

PURPOSE

To investigate the site of pudendal nerve compression and the relation between traction force and abduction angle regarding pressure levels at setup for hip arthroscopy.

METHODS

A total of 17 hips from 9 fresh-frozen cadavers (6 male and 3 female cadavers) were used. The pudendal nerves were dissected, and 3 FlexiForce force sensors (Tekscan, Boston, MA) were implanted on the pudendal nerve where the inferior rectal nerve, perineal nerve, and dorsal nerve of the clitoris/penis emerge. A custom-made traction table in a supine position was used with a padded perineal post of 9 cm. Recordings were made at 0, 10, 20, 30, and 40 kg of traction at varying hip abduction angles of 0°, 15°, 30°, and 45°.

RESULTS

The tuber ischiadicum (perineal nerve) and genital region (dorsal nerve of penis/clitoris) had statistically higher pressure values when compared with the pudendal canal (inferior rectal nerve) (P < .05). There was a significant increase in forces acting on the pudendal nerve with increasing application of 0 to 40 kg of traction in steps of 10 kg, with the exception of the pudendal canal sensor and reading of the perineal nerve sensor at 45° of hip abduction (P < .004 with Bonferroni correction for significant values). On the contrary, hip abduction angle had no statistically significant effect on pudendal nerve compression. (All specific P values with Bonferroni correction were greater than .003.)

CONCLUSIONS

To avoid nerve palsy completely, the etiopathogenesis of compressive neuropathy should be identified. The location for compression and relation between different traction positions and forces are clarified in this study. This information can be used for further research and prevention.

CLINICAL RELEVANCE

This study adds objective data on the etiopathogenesis of pudendal nerve compression, which potentially contributes to prevention of pudendal nerve palsy as a common complication of hip arthroscopy.

Position in the second stage of labour and de novo onset of post-partum urinary incontinence

INTRODUCTION AND HYPOTHESIS

The aim of this study was to evaluate the role of the maternal position at the time of delivery on the onset of de novo symptoms of urinary incontinence (UI) in the post-partum period.

METHODS

This prospective study evaluated the data of consecutive women undergoing labour and delivery, between January 2014 and July 2014. We included only women with a singleton pregnancy undergoing vaginal delivery. During the study period, patients chose to deliver in the position that they considered the most comfortable. The onset of UI was evaluated according to the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-sf).

RESULTS

Overall, 716 primiparous women were included in the study. Sixty women refused the 12-week post-partum interview (8.4%). Women were divided in two groups: 296 women (45.1%) who chose an upright position during delivery (group 1) and 360 women (54.9%) who chose a supine position (group 2). Group 1 had a significantly lower episiotomy rate, but a higher rate of greater than second degree perineal tears. In group 1 we found a significantly lower rate of de novo UI (40.5% vs 48.9%, p = 0.03) and in particular of stress urinary incontinence. Via multivariate analysis, birth position was the only factor correlating with the occurrence of urinary incontinence in the post-partum period (OR: 1.52; 95%CI: 1.06, 2.18; p = 0.02).

CONCLUSIONS

Upright positions at delivery are related to a lower episiotomy rate and a higher rate of greater than second degree perineal tears. Supine positions are an independent risk factor for the onset of de novo UI.

Delivery-related risk factors for covert postpartum urinary retention after vaginal delivery

Introduction and hypothesis

Postpartum urinary retention (PUR) is a common consequence of bladder dysfunction after vaginal delivery. Patients with covert PUR are able to void spontaneously but have a postvoid residual bladder volume (PVRV) of ≥150 mL. Incomplete bladder emptying may predispose to bladder dysfunction at a later stage of life. The aim of this cross-sectional study was to identify independent delivery-related risk factors for covert PUR after vaginal delivery in order to identify women with an increased risk of covert PUR.

Methods

The PVRV of women who delivered vaginally was measured after the first spontaneous micturition with a portable bladder-scanning device. A PVRV of 150 mL or more was defined as covert PUR. Independent risk factors for covert PUR were identified in multivariate regression analysis.

Results

Of 745 included women, 347 (47 %) were diagnosed with covert PUR (PVRV ≥150 mL), of whom 197 (26 %) had a PVRV ≥250 mL (75th percentile) and 50 (7 %) a PVRV ≥500 mL (95th percentile). In multivariate regression analysis, episiotomy (OR 1.7, 95 % CI 1.02 – 2.71), epidural analgesia (OR 2.08, 95 % CI 1.36 – 3.19) and birth weight (OR 1.03, 95 % CI 1.01 – 1.06) were independent risk factors for covert PUR. Opioid analgesia during labour (OR 3.19, 95 % CI 1.46 – 6.98), epidural analgesia (OR 3.54, 95 % CI 1.64 – 7.64) and episiotomy (OR 3.72, 95 % CI 1.71 – 8.08) were risk factors for PVRV ≥500 mL.

Conclusions

Episiotomy, epidural analgesia and birth weight are risk factors for covert PUR. We suggest that the current cut-off values for covert PUR should be reevaluated when data on the clinical consequences of abnormal PVRV become available.

Pudendal nerve 3-dimensional illustration gives insight into surgical approaches

The pudendal nerve is located topographically in areas in which plastic surgeon reconstruct the penis, the vagina, the perineum, and the rectum. This nerve is at risk for either compression or direct injury with neuroma formation from obstetrical, urogynecologic, and rectal surgery as well as pelvic fracture and blunt trauma. The purpose of this study was to create a 3-dimensional representation based on magnetic resonance imaging of the pelvis supplemented with new anatomic dissections in men and women to delineate the location of the pudendal nerve and its branches, providing educational information both for surgical intervention and patient education. The results of this study demonstrated that most often there are at least 2, not 1, "pudendal nerves trunks" as they leave the pelvis to transverse the sacrotuberous ligament, and that there are most often 2, not 1, exit(s) from Alcock canal, one for the dorsal branch and one for the perineal branch of the pudendal nerve.

A Case of Chronic Abdominal Neuropathic Pain and Burning after Female Genital Cutting

Introduction. Female genital cutting is prevalent in the Middle Eastern and African countries. This ritual entails not only immediate complications such as infection, pain, and haemorrhage, but also chronic ones including dysmenorrhea and dyspareunia. However, there is limited data on neuropathic pain secondary to female genital mutilation when searching the literature. Case. This case discusses a 38-year-old female with a history of infibulation who presented with a chronic burning abdominal and anterior vulvar pain including the related investigations and treatment. Discussion. This case brings to light the additional delayed complication of this ritual: sensory neuropathy. Our goal is to educate health professionals to be aware of these complications and to appropriately investigate and treat them in order to find a solution to relieve the patients' symptoms.

Differential expression of microRNAs in periurethral vaginal wall tissues of postmenopausal women with and without stress urinary incontinence

OBJECTIVE

The aims of this study were to investigate microRNA (miRNA) expression profiles in the periurethral vaginal wall tissues of postmenopausal women with and without stress urinary incontinence (SUI) and to explore the putative target genes associated with SUI via miRNA-messenger RNA (mRNA) pair prediction.

METHODS

Periurethral vaginal wall tissues of postmenopausal women with SUI (n = 13) and matched continent postmenopausal women (n = 13) were collected during transvaginal surgical operation. Total RNAs were extracted and miRNAs were profiled by TaqMan Array Human MicroRNA assays in three case-control pairs. TargetScanS, PicTar, and miRanda were used to obtain the putative miRNA-mRNA pairs based on sequence data, and three pairs were predicated. The relative expression levels of miRNAs in predicated miRNA-mRNA pairs were quantified in 10 other case-control pairs by real-time polymerase chain reaction. The expression levels of mRNAs and corresponding proteins were estimated via real-time polymerase chain reaction and Western blot analysis.

RESULTS

Twelve miRNAs were identified to be differentially expressed between two groups: the significantly up-regulated let-7a, miR-101#, miR-125b-2#, miR-190b, and miR-892b, and the down-regulated miR-124, miR-330-3p, miR-485-3p, miR-517b, miR-523, miR-589, and miR-93#. Moreover, three miRNA-mRNA pairs of interest were established via computational algorithms: miR-124 and growth factor receptor-bound protein 2; miR-330-3p and bicaudal D homolog 2; and miR-93# and signal transducer and activator of transcription 3. The expression levels of the three miRNAs were quantified, and a reduction in SUI was revealed. On the other hand, increased expression levels of predicated mRNAs and their protein products were detected.

CONCLUSIONS

This study reports the differential expression of 12 miRNAs in SUI and predicates three miRNA-mRNA pairs. Interestingly, all three predicated target genes are associated with neurodegenerative conditions, indicating the potential significance of neurodegenerative mechanisms in the etiology of SUI.

[Anatomy of the levator ani muscle and implications for obstetrics and gynaecology]

Pelvic floor disorders include urogenital and anorectal prolapse, urinary and faecal incontinence. These diseases affect 25% of patients. Most of time, treatment is primarily surgical with a high post-operative risk of recurrence, especially for pelvic organ prolapse. Vaginal delivery is the major risk factor for pelvic floor disorders through levator ani muscle injury or nerve damage. After vaginal delivery, 20% of patients experiment elevator ani trauma. These injuries are more common in case of instrumental delivery by forceps, prolonged second phase labor, increased neonatal head circumference and associated anal sphincter injuries. Moreover, 25% of patients have temporary perineal neuropathy. Recently, pelvic three-dimensional reconstructions from RMI data allowed a better understanding of detailed levator ani muscle morphology and gave birth to a clear new nomenclature describing this muscle complex to be developed. Radiologic and anatomic studies have allowed exploring levator ani innervation leading to speculate on the muscle and nerve damage mechanisms during delivery. We then reviewed the levator ani muscle anatomy and innervation to better understand pelvic floor dysfunction observed after vaginal delivery.

Brain-derived neurotrophic factor in urinary continence and incontinence

Urinary incontinence adversely affects quality of life and results in an increased financial burden for the elderly. Accumulating evidence suggests a connection between neurotrophins, such as brain-derived neurotrophic factor (BDNF), and lower urinary tract function, particularly with regard to normal physiological function and the pathophysiological mechanisms of stress urinary incontinence (SUI) and bladder pain syndrome/interstitial cystitis (BPS/IC). The interaction between BDNF and glutamate receptors affects both bladder and external urethral sphincter function during micturition. Clinical findings indicate reduced BDNF levels in antepartum and postpartum women, potentially correlating with postpartum SUI. Experiments with animal models demonstrate that BDNF is decreased after simulated childbirth injury, thereby impeding the recovery of injured nerves and the restoration of continence. Treatment with exogenous BDNF facilitates neural recovery and the restoration of continence. Serotonin and noradrenaline reuptake inhibitors, used to treat both depression and SUI, result in enhanced BDNF levels. Understanding the neurophysiological roles of BDNF in maintaining normal urinary function and in the pathogenesis of SUI and BPS/IC could lead to future therapies based on these mechanisms.