Is it necessary to diagnose levator avulsion on pelvic floor muscle contraction?

Diagnosis of maternal birth trauma by pelvic floor ultrasound

BRIEF SUMMARY

Maternal somatic birth trauma due to vaginal delivery is more common than generally assumed and an important cause of future morbidity. Maternal birth trauma may involve both psychological and somatic morbidity, some of it long-term and permanent. Somatic birth trauma is now understood to encompass not just episiotomy, perineal tears and obstetric anal sphincter injuries (OASI), but also trauma to the levator ani muscle, termed 'avulsion'. This review will focus on recent developments in the imaging diagnosis of maternal birth trauma, discuss the most important risk factors and strategies for primary and secondary prevention. Translabial and exo-anal ultrasound allow the assessment of maternal birth trauma in routine clinical practice and enable the use of levator avulsion and anal sphincter trauma as key performance indicators of maternity services. This is likely to lead to a greater awareness of maternal birth trauma amongst maternity caregivers and improved outcomes for patients, not the least due to an increasing emphasis on patient autonomy and informed consent in antenatal and intrapartum care.

Association Between Urinary Stress Incontinence and Levator Avulsion Detected by 3D Transperineal Ultrasound

PURPOSE

 To determine the association between levator avulsion and urinary stress incontinence (USI) by 3/4D transperineal ultrasound.

MATERIALS AND METHODS

 842 patients who were admitted to our hospital from 2016 to 2019 were recruited for our study. 3D/4D transperineal ultrasound was performed. After standard interview and clinical evaluation, general conditions and levator hiatus data were collected and measured to compare with each group. The odds ratio (OR) of USI symptoms or ultrasound features with levator avulsion were calculated.

RESULTS

 A total of 593 women were studied: 204 suffered from levator avulsion (96 cases of left-side avulsion, 80 cases of right-side avulsion and 28 cases of bilateral avulsion) and 389 women had no avulsion. The gravidity and episiotomy conditions of the avulsion groups were significantly different from the no-avulsion group. Significant differences were found in the transverse diameters and anteroposterior diameters between the levator avulsion group and the no-avulsion group, but there was no difference among the avulsion groups, regardless of whether the patient was at rest or performing the Valsalva maneuver. Interestingly, a significant difference was found in the presence of USI symptoms between the uni-avulsion group and the no-avulsion group. The odds ratio (OR) of USI symptoms in the uni-avulsion group is 2.786 (95 %CI, 1.663-4.669), but 0.939 (95 %CI, 0.276-3.199) for the bilateral avulsion and no-avulsion groups.

CONCLUSION

 Unilateral levator avulsion may be a risk factor for urinary stress incontinence.

Transvaginal Two-Dimensional Ultrasound Evaluation as a Screening Tool for Levator ani Muscle Avulsion in Postpartum Women

OBJECTIVES

To evaluate the agreement between two-dimensional transvaginal ultrasound (2D-TVUS) and transperineal tomographic ultrasound imaging on three-dimensional (3D) volume in diagnosing levator ani muscle (LAM) avulsion of postpartum women. Furthermore, we tested the repeatability of the 2D-TVUS in measuring the LAM thickness.

METHODS

A retrospective study was performed using the data sets from postpartum women. One doctor measured the thickness of the LAM on the images at the attachment to the arcus tendinous levator ani and the middle part using the 2D-TVUS ultrasound data sets of postpartum women. These women were examined twice, at 42-56 days and 3-6 months postpartum. Intra-observer repeatability was expressed using intraclass correlation coefficients (ICCs). The other doctor judged whether there was avulsion in the LAM on the 2D-TVUS and transperineal tomography imaging on the 3D volume. The inter-method agreement was determined using Cohen's kappa coefficient (k).

RESULTS

Thickness measurements of the middle part and attachment of the LAM by 2D-TVUS showed excellent and good intra-observer repeatability (ICC 0.84; 95% CI, 0.76-0.88, and ICC 0.74; 95% CI, 0.67-0.84, respectively). The overall agreement was 92% (Cohen's kappa was 0.79) between 2D-TVUS and transperineal tomographic imaging. Compared to transperineal tomographic imaging in the diagnosis of LAM avulsion, the diagnostic sensitivity of 2D-TVUS was 91.7%, the specificity was 92.1%.

CONCLUSIONS

The 2D-TVUS technique, a simple and reproducible method for assessing LAM avulsion, may be helpful as a screening tool for LAM avulsion of postpartum women.

Multicenter study of the evolution of different types of avulsion over the 12 months after delivery

OBJECTIVE

To perform a multicenter study of muscle recovery in levator ani muscle (LAM) avulsion during the first 12 months postpartum according to the type of LAM avulsion suffered.

METHODS

This was a multicenter prospective observational study including 242 primiparas. Transperineal ultrasound was performed at 6 months and 12 months after delivery. Type I LAM avulsion was present when most of the lateral fibers of the pubovisceral muscle were observed at the muscle's insertion at the pubic level. Type II LAM avulsion was defined as complete detachment of the pubovisceral muscle from its insertion at the pubic level.

RESULTS

Among the 56 patients who completed the study (with ultrasound at 6 and 12 months after delivery), 76 avulsions (10 cases of bilateral avulsion) were identified at 6 months after delivery, and the total number of avulsions had decreased to 58 at 12 months after delivery (P < 0.001; 95% confidence interval [CI] 13.9%-33.5%). This decrease was due to the disappearance of 69.2% of the cases of Type I LAM avulsions (P < 0.001; 95% CI: 50.2%-88.2%). However, the number of Type II LAM avulsions remained constant at 6 months and 12 months after delivery.

CONCLUSION

The spontaneous resolution of LAM avulsion during the first 12 months postpartum occurs in cases of Type I LAM avulsion but is not observed in Type II LAM avulsion.

Are Transperineal Ultrasound Parameters Useful to Predict Incontinence in Patients with Single-Incision Mini-Slings?

It would be logical to think that single-incision mini-slings (SIMS) should behave like the rest of the tension-free vaginal tape and, therefore, to believe that they present a similar ultrasound appearance, but there are no studies on this matter. Therefore, the main aim of our research is to determine which ultrasound parameters are associated with stress urinary incontinence (SUI) in patients carrying SIMS. A prospective observational study was carried out including 94 patients who were candidates for SUI corrective surgery with SIMS between 1 January 2021 to 31 December 2021 at the Universitary Hospital of Valme (Seville, Spain). A transperineal ultrasound evaluation was performed (six months after surgery) in order to study: the bladder neck–symphyseal distance, the posterior urethro–vesical angle, the pubic symphysis–tape gap, the tape–urethral lumen distance, the sagittal tape angle, the tape position, the concordance of movement between the tape and the urethra, and the axial tape angle. A total of 92 patients completed the study (63 asymptomatic and 29 symptomatic). Statistical differences were observed in the concordance of movement between the tape and the urethra (84.1% vs. 25.0%; p: 0.001) and in the axial tape angle at rest (139.3 ± 19.0 vs. 118.3 ± 15.4; p: 0.003) and at Valsalva (145.1 ± 20.2 vs. 159.1 ± 9.0; p: 0.034). Sagittal tape angle at rest was higher in urge urinary incontinence (UUI) patients (132.5 ± 35.7 vs. 143.3 ± 29.8; p: 0.001) and mixed urinary incontinence (MUI) patients (132.5 ± 35.7 vs. 157.8 ± 23.6; p: 0.025) compared to asymptomatic patients. In conclusion, the concordance between the movement of the tape and the urethra is the most useful ultrasound parameter to define continence in patients with SIMS.

Predictive Model for the Diagnosis of Uterine Prolapse Based on Transperineal Ultrasound

We want to describe a model that allows the use of transperineal ultrasound to define the probability of experiencing uterine prolapse (UP). This was a prospective observational study involving 107 patients with UP or cervical elongation (CE) without UP. The ultrasound study was performed using transperineal ultrasound and evaluated the differences in the pubis−uterine fundus distance at rest and with the Valsalva maneuver. We generated different multivariate binary logistic regression models using nonautomated methods to predict UP, including the difference in the pubis−uterine fundus distance at rest and with the Valsalva maneuver. The parameters were added progressively according to their simplicity of use and their predictive capacity for identifying UP. We used two binary logistic regression models to predict UP. Model 1 was based on the difference in the pubis−uterine fundus distance at rest and with the Valsalva maneuver and the age of the patient [AUC: 0.967 (95% CI, 0.939−0.995; p < 0.0005)]. Model 2 used the difference in the pubis−uterine fundus distance at rest and with the Valsalva maneuver, age, avulsion and ballooning (AUC: 0.971 (95% CI, 0.945−0.997; p < 0.0005)). In conclusion, the model based on the difference in the pubis−uterine fundus distance at rest and with the Valsalva maneuver and the age of the patient could predict 96.7% of patients with UP.

The Role of Transperineal Ultrasound for the Assessment of the Anorectal Angle and Its Relationship with Levator Ani Muscle Avulsion

The relationship between the anorectal angle (ARA) and the levator ani muscle (LAM) is well known. In this study, we aimed to demonstrate that the ARA changes when LAM avulsion occurs after vaginal delivery. This was a secondary, observational retrospective study with data obtained from three previous studies. Using transperineal ultrasound, the presence of avulsion was assessed when abnormal insertion of the LAM was observed in three central slices. In addition, the ARA was assessed in the midsagittal plane (at rest, in Valsalva and at maximum contraction) as the angle between the posterior border of the distal part of the rectum and the central axis of the anal canal. The ARA was higher in patients with bilateral LAM avulsion than in patients without LAM avulsion at rest (131.8 ± 14.1 vs. 136.2 ± 13.8), in Valsalva (129.4 ± 15.5 vs. 136.5 ± 14.4) and at maximum contraction (125.7 ± 15.5 vs. 132.3 ± 13.2). The differences between both groups expressed as the odds ratio (OR) adjusted for maternal age were 1.031 (95% confidence interval (CI), 1.001–1.061; p = 0.041) at rest, 1.036 (95% CI, 1.008–1.064; p = 0.012) in Valsalva and 1.031 (95% CI, 1.003–1.059; p = 0.027) at maximum contraction. In conclusion, LAM avulsion produces an increase in the ARA at rest, during contraction and in Valsalva, especially in cases of bilateral LAM avulsion.

2D pelvic floor ultrasound imaging in identifying levator ani muscle trauma agrees highly with 4D ultrasound imaging

INTRODUCTION AND HYPOTHESIS

The objective was to evaluate the agreement between 2D and 4D translabial ultrasound (TLUS) technique in showing levator ani muscle (LAM) states after vaginal birth.

METHODS

In a prospective observational cohort study between March 2017 and April 2019 we evaluated LAM states (intact, hematoma, partial, complete avulsion) of primiparous women having given birth vaginally with singletons in vertex presentation ≥ 36+0 gestational weeks by using 2D and 4D TLUS within 1-4 days postpartum (assessment A1) and again 6-10 weeks postpartum (assessment A2). Cohen's Kappa analysis was performed for each side separately to evaluate the test agreement between the two ultrasound techniques at every assessment period.

RESULTS

A total of 224 women participated at A1 and 213 at A2. The agreement between the two ultrasound techniques was good to very good at A1 (Cohen`s kappa right-sided 0.78, left-sided 0.82) and very good at A2 (Cohen`s kappa both sides 0.88). The agreement was best when assessing an intact LAM or a complete avulsion (Cohen`s kappa between 0.78-0.92 for complete avulsions).

CONCLUSIONS

The comparison between 2D and 4D TLUS showed a good to very good agreement in LAM trauma immediately after birth as well as 6-10 weeks postpartum. Therefore, 2D ultrasound could also be a valuable method for demonstrating a LAM abnormality and could be used in settings where 3D/4D ultrasound equipment is not available.

The correlation between levator ani co-activation and fetal head regression on maternal pushing at term

OBJECTIVE

To assess the correlation between fetal head regression and levator ani muscle (LAM) co-activation under Valsalva maneuver.

STUDY DESIGN

This study was a secondary analysis of a prospective cohort study on the association between the angle of progression (AoP) and labor outcome. We scanned a group of nulliparous women at term before the onset of labor at rest and under maximum Valsalva maneuver. In addition to the previously calculated AoP, in the present study, we measured the anteroposterior diameter of LAM hiatus (APD) on each ultrasound image. LAM co-activation was defined as APD at Valsalva less than that at rest, whereas fetal head regression was defined as AoP at Valsalva less than that at rest. We calculated the correlation between the two phenomena. Finally, we examined various labor outcomes according to the presence, absence, or co-existence of these two phenomena.

RESULTS

We included 469 women. A total of 129 (27.5%) women presented LAM co-activation while 50 (10.7%) showed head regression. Only 15 (3.2%) women showed simultaneous head regression and LAM co-activation. Women with coexisting LAM co-activation and head regression had the narrowest AoP at Valsalva in comparison with other study groups (p < .001). In addition, they had the highest risk of Cesarean delivery (40%) and longest first, second, and active second stage durations, although none of these reached statistical significance.

CONCLUSION

In nulliparous women at term before the onset of labor fetal head regression and LAM co-activation at Valsalva are two distinct phenomena that uncommonly coexist.

The evolution of levator ani muscle trauma over the first 9 months after vaginal birth

INTRODUCTION AND HYPOTHESIS

The objective was to investigate the evolution of levator ani muscle (LAM) trauma over the first 9 months after birth and to evaluate their agreement between different assessment periods.

METHODS

From March 2017 to April 2019 we prospectively evaluated LAM states (intact, hematoma, partial or complete avulsion) of primiparous women after vaginal birth by using 4D translabial ultrasound (TLUS) at three different assessment periods. All women were examined 1-4 days (A1) and 6-10 weeks (A2) postpartum, and women with a trauma additionally 6-9 months postpartum (A3). Cohen's Kappa analysis was performed to evaluate the test agreement between the assessment periods.

RESULTS

Thirty-two percent of the women at A1 had a LAM trauma and 24% at A2. The higher number of LAM injuries at A1 can be explained by hematomas (14%), of which 51% spontaneously resolved at A2, 35% revealed themselves as partial, and 12% as complete avulsions. At A3, we observed anatomical improvement from complete to partial avulsions (23%) and few partial avulsions changed into an intact LAM (3%); none of the complete avulsions changed into an intact LAM. The agreement of 4D TLUS between A1 and A2 was moderate to good (0.64 for the right-sided LAM/0.60 for the left-sided LAM) and between A2 and A3 good to very good (0.76 right-sided/0.84 left-sided).

CONCLUSIONS

Levator ani muscle trauma can reliably be diagnosed during all assessment periods. However, the agreement between A1 and A2 was only moderate to good. This can be explained by hematomas inside the LAM that were only observed early postpartum. We observed some anatomical improvement at A3, but no complete avulsion improved to an intact LAM.

Effects of yoga on the intervention of levator ani hiatus in postpartum women: a prospective study

[Purpose] This study aimed to explore the application value of yoga intervention in early postpartum recovery of the levator ani muscle hiatus (LAH) area. [Participants and Methods] Females in natural labor from May 2020 to November 2020 in the Third People’s Hospital of Sun Yat-sen University Ultrasound Research Center were prospectively included for a pelvic ultrasound examination. The control group received no intervention. The experimental group received 60-min yoga once a week from week 1 to week 12 postpartum. A pelvic ultrasound examination was performed on the week 6 and week 12 postpartum. The LAH area was measured at rest, during contraction and Valsalva maneuver. [Results] A total of 128 participants who met the inclusion criteria were selected and randomly assigned to the control group (n=66) and the experimental group (n=62) in pre and post intervention design. No significant differences were found in age, parity, body mass index, and fetal weight between the control and experimental groups. Further, no significant difference was observed in the LAH area between the control and experimental groups at rest, during contraction and Valsalva maneuver on the week 6 postpartum. However, the LAH area in experimental group significantly reduced at rest, during contraction and Valsalva maneuver on the week 12 postpartum. The differences of LAH area (date week 6 minus date week 12) in the control group at rest, during contraction and Valsalva maneuver were 0.12 ± 3.12 cm², 0.80 ± 2.29 cm², and 0.80 ± 4.22 cm², while in the control these were 1.95 ± 3.41 cm², 1.39 ± 1.91 cm², and 3.81 ± 5.49 cm², respectively. Compared with control group, the differences of LAH area significantly increased in experimental group at rest and during Valsalva maneuver. [Conclusion] Yoga intervention can help in the recovery of LAH.

Ultrasound imaging of maternal birth trauma

INTRODUCTION AND HYPOTHESIS

The term 'maternal birth trauma' has undergone substantial changes in meaning over the last 2 decades. Leaving aside psychological morbidity, somatic trauma is now understood to encompass not just episiotomy, perineal tears and obstetric anal sphincter injuries (OASI), but also trauma to the levator ani muscle. This review covers diagnosis of maternal birth trauma by translabial ultrasound imaging.

METHODS

Narrative review.

RESULTS

Tomographic imaging of pelvic structures with the help of 4D ultrasound, used since 2007, has allowed international standardization and seems to be highly reproducible and valid for the diagnosis of OASI and levator avulsion.

CONCLUSIONS

Translabial and exo-anal ultrasound allows the assessment of maternal birth trauma in routine clinical practice and the utilization of avulsion and sphincter trauma as key performance indicators of maternity services. It is hoped that this will lead to a greater awareness of maternal birth trauma among maternity caregivers and improved outcomes for patients, both in the short term and in the decades to come.

Type of levator ani muscle avulsion as predictor for the disappearance of avulsion

OBJECTIVES

The objective of our study was to establish whether the type of levator ani muscle (LAM) avulsion diagnosed 6 months after delivery influences the integrity of the LAM at 1 year after delivery and determine its influence on the levator hiatus area.

STUDY DESIGN

This observational prospective cohort study included 192 primiparous women with vaginal delivery. Transperineal ultrasound examinations were performed at 6 months and 1 year postpartum. Levator hiatus measurements (anteroposterior diameter, transverse diameter, and area) were performed in the plane of minimal dimensions. Complete avulsion was defined based on maximum contraction in multislice mode. Type I LAM avulsion was present when most lateral fibers of the pubovisceral muscle were observed at its insertion at the pubic level (the arch of the elevator remained intact). Type II LAM avulsion was defined as a complete detachment of the pubovisceral muscle from its insertion at the pubic level.

RESULTS

In total, 192 patients were recruited after delivery; 48 patients were diagnosed with complete LAM avulsion, and 13 patients with avulsion did not attend the second ultrasound follow-up at 1 year after delivery. Thirty-five patients with complete LAM avulsion were included in the study. At 6 months after delivery, 51 LAM avulsions were observed in 35 patients (including bilateral LAM avulsion in 16 cases), of which 54.9% were right avulsions and 45.1% left avulsions. Furthermore, 11 (five right and six left) were type I LAM avulsions at the 6-month assessment, and all of these had disappeared 1 year after delivery. However, none of the type II LAM avulsions (23 right and 17 left) observed at 6 months had disappeared at the second ultrasound examination. There were no differences between the LAM areas detected at the first and second ultrasound examinations (10.2 ± 3.3 vs 9.3 ± 1.8; P = .404).

CONCLUSIONS

The type of LAM avulsion observed at 6 months after childbirth predicts LAM persistence at 1 year postpartum.

Association between sexual dysfunction and avulsion of the levator ani muscle after instrumental vaginal delivery

INTRODUCTION

The effects of levator ani muscle (LAM) avulsion after instrumental delivery on the sexual function of patients are currently unknown. Therefore, the objective of our study was to use a validated questionnaire, namely, the Female Sexual Function Index (FSFI), to compare the sexual function in patients with and without LAM avulsion after instrumental vaginal delivery.

MATERIAL AND METHODS

This was a prospective observational study of 112 primiparous women after instrumental (vacuum or forceps) vaginal delivery. The obstetric and general characteristics of the population were studied. At 6 months postpartum, the contraceptive method used and the occurrence of LAM avulsion (using four-dimensional transperineal ultrasound) were determined, and the FSFI was administered.

RESULTS

A total of 100 patients (62 without avulsion and 38 with avulsion) completed the study. Thirty-eight (38%) were diagnosed with avulsion (42.1% after Kielland forceps delivery, 57.9% after Malmström vacuum delivery; P = .837). Women with LAM avulsion had significantly lower scores for desire (2.9 ± 1.2 vs 3.4 ± 1.1; P = .049), arousal (2.8 ± 1.7 vs 3.6 ± 1.4; P = .014), lubrication (2.3 ± 1.4 vs 3.0 ± 1.2; P = .011), orgasm (2.6 ± 1.6 vs 3.3 ± 1.2; P = .006) and satisfaction (3.1 ± 1.8 vs 3.9 ± 1.5; P = .051) than did women without LAM avulsion. The overall FSFI score was lower in patients with avulsion (16.7 ± 8.9 vs 20.7 ± 6.9, P = .033). These results were obtained after controlling for confounders (delivery mode, induced labor, birthweight, perineal tears, avulsion degree, contraceptive method and group assignment for the parent study) in the multivariate analysis (F = 4.974, P = .001).

CONCLUSIONS

Patients with LAM avulsion present a higher degree of sexual dysfunction compared wiith patients without avulsion at 6 months after instrumental vaginal delivery.

Malmström vacuum or Kielland forceps: which causes more damage to pelvic floor?

OBJECTIVE

To determine whether differences exist in the rate of levator ani muscle (LAM) avulsion between women who had undergone either Malmström vacuum delivery (MVD) or Kielland forceps delivery (KFD), allowing for potential confounding factors.

METHODS

This was a prospective observational study of nulliparous women undergoing instrumental delivery using Malmström vacuum extractor or Kielland forceps, at two hospital centers in Spain. Fetal head position (anterior, posterior or transverse) and fetal head station (low or mid) were assessed by ultrasound and digital examination, respectively. Avulsion was defined on tomographic ultrasound imaging as an abnormal insertion of the LAM in the three central slices from the plane of minimal hiatal dimensions.

RESULTS

In total, 414 patients were included in the study (212 MVD and 202 KFD). We observed a higher rate of LAM avulsion in the KFD group (KFD 49.5% vs MVD 32.5%; P = 0.001). When the results were evaluated according to fetal head position and station, we observed no differences in LAM avulsion. The crude odds ratio (OR) for the difference in avulsion between women in the KFD and MVD groups was 2.03 (95% CI, 1.36-3.03). However, when adjusted for duration of second stage of labor, fetal head circumference and fetal head station, the OR was no longer statistically significant (OR, 2.14 (95% CI, 0.95-4.85); P = 0.068).

CONCLUSION

When potential confounding factors are taken into account, the rate of LAM avulsion does not differ between women according to whether they have undergone KFD or MVD. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Anal sphincter imaging: better done at rest or on pelvic floor muscle contraction?

INTRODUCTION AND HYPOTHESIS

Exo-anal ultrasound imaging of the anal sphincter is usually undertaken on pelvic floor muscle contraction (PFMC) as this seems to enhance tissue discrimination. Some women are unable to achieve a satisfactory PFMC, and in this situation, the sphincter is assessed at rest. We aimed to determine whether sphincter imaging at rest is inferior to imaging on PFMC.

METHODS

We analysed 441 women in this retrospective study. All underwent a standardised interview, including St Mark's incontinence score, clinical examination and 4D trans-labial ultrasound (TLUS). On analysing volume data, tomographic imaging was used to obtain a standardised set of slices at rest and on PFMC to evaluate external anal sphincter (EAS) and internal anal sphincter (IAS) trauma as described previously.

RESULTS

When assessments obtained from volumes acquired at rest and on PFMC were tested against measures of anal incontinence (AI), all associations between the diagnosis of significant anal sphincter defects and AI were no stronger when imaging was performed on PFMC. On cross-tabulation, the percentage agreement for significant defects of the EAS and IAS at rest and on PFMC was 96.5% and 98.9% respectively, if discrepancy by one slice was allowed.

CONCLUSIONS

Exo-anal tomographic imaging of sphincter defects at rest seems sufficiently valid for clinical use and may not be inferior to sphincter assessment on pelvic floor muscle contraction.

Influence of the disengagement of the forceps on levator ani muscle injuries in instrumental delivery: A multicenter study

INTRODUCTION

Forceps use is the main risk factor for levator ani muscle (LAM) injuries. We believe that the disengagement of the forceps branches before delivery of the fetal head could influence LAM injuries, so we aimed to determine the influence of the disengagement of the forceps on the occurrence of LAM avulsion during forceps delivery.

MATERIAL AND METHODS

A prospective, observational, multicenter study was conducted with 261 women who underwent forceps delivery. The women were classified according to whether the branches of the forceps had been disengaged before delivery of the fetal head. LAM avulsion was defined using a multislice mode (3 central slices).

RESULTS

In all, 255 women completed the study (160 without disengagement and 95 with disengagement). LAM avulsions were observed in 37.9% of women in the group with disengagement and in 41.9% of women in the group without disengagement. The crude OR (without disengagement vs with disengagement) for avulsion was 0.90 (95% CI 0.49-1.67, P = 0.757) and an adjusted OR of 0.82 (95% CI 0.40-1.69, P = 0.603).

CONCLUSIONS

We did not observe a statistically significant reduction in the LAM avulsion rate with disengagement of the forceps branches before delivery of the fetal head.

Association between pelvic organ prolapse types and levator-urethra gap as measured by 3D transperineal ultrasound

OBJECTIVES

To evaluate the association between pelvic organ prolapse (POP) types and levator-urethra gap (LUG) as measured by 3-dimensional transperineal tomographic ultrasound.

METHODS

A retrospective study was carried out on 98 women with symptomatic POP. Three-dimensional transperineal tomographic ultrasound images and POP quantification coordinates were reviewed. Each vaginal compartment was staged for the degree of prolapse, and total number of involved compartments identified. LUG was measured on 3-dimensional tomographic sonograms as the distance between the center of the urethra and the levator insertion bilaterally. Based on prior studies, an abnormal LUG of 25 mm or greater indicated levator avulsion. The LUG and the presence or absence of unilateral/bilateral avulsions was analyzed with reference to the clinical diagnosis of prolapse (single versus multicompartment, and mild [stage II] versus severe [stage III-IV]). Generalized logit models were used to evaluate the association between avulsion and prolapse type and stage.

RESULTS

The LUG was substantially larger in women with multicompartment compared to single-compartment POP (28.9 ± 4.1 mm versus 22.7 ± 4.1 mm, P < .01). Similarly, LUG was substantially larger in women with severe (stage III-IV) compared to mild (stage II) POP (28.8 ± 4.7 mm versus 23.3 ± 4.5 mm, P < .01). Women with severe prolapse were 32 times more likely than women with mild prolapse to have bilateral levator avulsion. Those with POP involving all 3 vaginal compartments were 76 times more likely than single-compartment POP to have bilateral levator avulsions.

CONCLUSIONS

Bilateral levator ani avulsion as diagnosed by LUG measurements of 25 mm or greater at rest is associated with multicompartment, severe prolapse.

Ultrasound in the assessment of pelvic organ prolapse

Imaging is increasingly being used in urogynaecology. Because of low cost and universal availability, ultrasound (US) is the most commonly used diagnostic modality, which allows the observation of manoeuvres such as Valsalva and pelvic floor muscle contraction in real time. The ability to see beyond surface anatomy is particularly important in the posterior compartment and in obstructed defecation where this method may replace defecation proctography. Imaging is especially useful in the form of 3D/4D multiplanar and tomographic translabial US, as these modalities give access to the axial plane and the levator ani. This allows assessment of both avulsion, i.e. major maternal birth trauma, and hiatal overdistension, i.e. ballooning. Both are major risk factors for both prolapse and prolapse recurrence. This review will outline current clinical utility, introduce recent research in the respective field and provide an overview of likely future utility of imaging in the investigation of pelvic organ prolapse.