Dynamic transurethral sonography and 3-dimensional reconstruction of the rhabdosphincter and urethra: initial experience in continent and incontinent women

Pelvic floor ultrasound versus urodynamics in evaluating insensible urinary incontinence: A retrospective study

OBJECTIVE

Insensible Urinary Incontinence (IUI) is a situation when you complain of urinary incontinence but are unaware of how it occurred. Therefore, it is necessary to apply highly specific diagnostic methods to promote accuracy in the diagnosis of IUI, including pelvic floor ultrasound (PFU) and urodynamic studies (UDS).

METHODS

A total of 41 women with IUI were retrospectively included. Patients were categorized into two groups: the urodynamic urinary incontinence group (UUI group, n=20) and the non-urodynamic urinary incontinence group (NUUI group, n=21), according to the urine leakage during UDS. The baseline clinical characteristics, UDS results, and PFU parameters were collected.

RESULTS

Compared with the NUUI group, the UUI group had a smaller maximum cystometric capacity (P=0.008), lower maximum urethral closure pressure (P=0.005), shorter functional urethral length (FUL) (P=0.01), more bladder neck funneling (BNF) (P=0.02), greater BNF depth (P=0.04), and larger BNF area (P=0.01). The area and depth of BNF were negatively correlated with maximum urethral closure pressure (r=-0.42, P=0.01), FUL (r=-0.36, P=0.02 versus r=-0.39, P=0.01), and maximum cystometric capacity (r=-0.35, P=0.03), but positively correlated with maximum urinary flow rate (r=0.33, P=0.04 versus r=0.36, P=0.02). The canonical correlation analysis of the ultrasound parameters and UDS parameters shows that the first pair of canonical variables was statistically significant (r1=0.9, P<0.001).

CONCLUSIONS

The PFU is associated with UDS in evaluating IUI. It has the advantages of low cost and high comfort, thus should be used as an auxiliary examination for IUI.

Changes in Morphology of the Urethral Rhabdosphincter Postpartum

OBJECTIVE

The aim of the study was to determine the effect of pregnancy on urethral rhabdosphincter cross-sectional area (CSA) and any association of CSA to urinary symptoms.

METHODS

Nulliparous women planning pregnancy (N = 135) underwent standardized evaluations (symptom and quality of life [QOL] questionnaires, magnetic resonance imaging, ultrasonography, and neurophysiologic testing) between January 2008 and December 2013 (V1). The participants who became pregnant and gave birth underwent the same evaluations at 6 weeks (V2) and 6 months postpartum (V3). Participants who had magnetic resonance imaging data from both V1 and V3 were selected. We measured urethral rhabdosphincter CSA from high-resolution axial MRIs in a masked fashion. The mean CSA for each participant was calculated. The change from V1 to V3 was assessed.

RESULTS

Sixty-eight women were evaluated. There was a significant decrease of 0.05 cm2 (interquartile range, -0.03 to 0.16 cm2; P = 0.002) in the median sphincter CSA between V1 and V3. There was a significant increase in the median Urinary Distress Inventory (UDI) subscore of the Pelvic Floor Distress Inventory (PFDI) from V1 to V3 (median increase of 0 [IQR, 0 to 8.3]; P = 0.033), but this was not significantly correlated with the change in the urethral CSA (Spearman correlation, 0.199; P = 0.107). Increasing fetal weight was correlated with a decrease in CSA postpartum after vaginal birth (Spearman correlation, -0.340; P = 0.017).

CONCLUSIONS

There is a decrease in urethral rhabdosphincter CSA with worsening Urinary Distress Inventory scores from prepregnancy to postpartum, but these two do not correlate in this cohort with low symptom levels. Among women who give birth vaginally, decrease in rhabdosphincter CSA is correlated with increasing fetal weight, perhaps with ramifications to be seen later in life.

Method and reliability of measuring midurethral area and echogenicity, and changes during and after pregnancy

Introduction and hypothesis

Internal closure of the urethral sphincter is one of the mechanisms in maintaining continence. Little is known about changes in the urethral sphincter during pregnancy. We designed this study to develop a reliable method to measure the area and mean echogenicity of the midurethra during and after pregnancy and to assess changes over time.

Methods

Two observers independently segmented the urethra as follows: in the sagittal plane, the urethra was positioned vertically, the marker was placed in the middle section of the lumen of the urethra, and eight tomographic US images of 2.5 -mm slices were obtained. The central image was selected, and area and mean echogenicity were calculated automatically. Intra- and interobserver reliability were determined by intraclass correlation coefficients (ICC) and their 95% confidence intervals (CI). Two hundred and eighty women underwent TPUS at 12 weeks and 36 weeks of gestation and 6 months postpartum, and 3D/4D transperineal ultrasound (TPUS) images of 40 pregnant nulliparous women were used for the reliability study. Paired t tests were used to assess changes in echogenicity and area.

Results

The ICC for measuring the area was substantial, at 0.77 and for measuring mean echogenicity was almost perfect, at 0.86. In the total study group (n = 280), midurethral area and mean echogenicity were significantly lower 6 months after delivery compared with 12 and 36 weeks of gestation.

Conclusions

Our protocol for measuring area and mean echogenicity of the midurethra is reliable. This study indicates that structural changes in the midurethraoccur during pregnancy.

Size Does Not Make the Difference: 3D/4D Transperineal Sonographic Measurements of the Female Urethra in the Assessment of Urinary Incontinence Subtypes

Purpose. The objective was to evaluate the usefulness of transperineal ultrasound in the assessment of the urethral length and urethral lumen by 3D/4D transperineal sonography to discriminate between female patients with subtypes of urinary incontinence. Methods. A total of 150 female patients underwent an examination because of urinary incontinence. 41 patients were diagnosed with urgency urinary incontinence (OAB), 67 patients were diagnosed with stress urinary incontinence (SUI), and 42 patients were in the control group (CTRL). Three diameters of the urethral lumen (proximal (U1), medial (U2), and distal (U3)) and the urethral length were measured. By the assessment of the urethral lumen, the presence of the urethral funneling was evaluated. Results. We found a significant difference in the urethral length and urethral lumen U2 of OAB and SUI versus CTRL. The urethral length was significantly greater (P < 0.05) and the urethral lumen was significantly wider (P < 0.05) in the patients with urinary incontinence. The incidence of the urethral funneling was significantly higher (P < 0.05) in the study groups with urinary incontinence than in the control group. Conclusions. Our results have shown the urethral changes obtained by ultrasound in patients with urinary incontinence, but they are still insufficient to distinguish between subtypes of urinary incontinence.

Is there a correlation between levator ani and urethral sphincter complex status on 3D ultrasonography?

INTRODUCTION AND HYPOTHESIS

To determine the correlation between levator ani deficiency (LAD) and urethral sphincter complex measurements as visualized on 3D endovaginal ultrasonography, and to compare the LAD score with continence status.

METHODS

This was a retrospective analysis of patients seen at our institution between January 2011 and August 2013. Patients were dichotomized into those with urodynamic stress urinary incontinence (SUI) and those with no SUI. Levator ani status was evaluated using a validated scoring system yielding scores of 0 - 6 (normal levator ani/mild LAD), 7 - 12 (moderate LAD), and 13 - 18 (severe LAD). The length, horizontal diameter, and cross-sectional area of the urethra, and the length, width, and the area of the rhabdomyosphincter and smooth muscle sphincter were likewise measured using 3D ultrasound volumes.

RESULTS

Of the 80 patients included, 54 (67.5%) had SUI and 26 (32.5%) were continent. 18 (22.5%) had evidence of mild LAD, 54 (67.5%) had moderate LAD, and 8 (10.0%) had severe LAD. Among patients with SUI, those with normal levator ani muscles or mild LAD had greater urethral smooth muscle width than those with moderate and severe LAD (p = 0.0238). A greater proportion of patients with SUI also had moderate to severe LAD than continent patients (p = 0.0177, OR 3.59, 95% CI 1.21 - 10.65). There was no difference in LAD distribution by type of stress incontinence (presence or absence of intrinsic sphincter deficiency; p =  .2377).

CONCLUSIONS

LAD and urethral sphincter complex status, as visualized on 3D ultrasonography, are independent factors. Moderate to severe LAD is more prevalent in patients with SUI.

ASSESSMENT OF VOIDING FUNCTION BY ENDOSCOPIC IMAGING — A PRELIMINARY REPORT

We report a novel method of reconstructing the 3D structure of the prostatic urethra and measuring its elasticity using endoscopic video images, and discuss their relation to clinical relevancy. Information regarding pixel color and brightness in the endoscopic video image is converted to relative distance between the object and the light source. An opened, 3D image of the prostatic urethra is obtained from a video image captured by the endoscope as it is slowly pulled through the urethra. The elasticity of the urethra is determined by recording a video image of the endoscope fixed in the prostatic urethra, with and without irrigation under water pressure of approximately 80 cm H 2 O . Angulation of the prostatic urethra is estimated by the number of intersections between the outline of protruded prostate and the midline of the urethra in patients with severe voiding dysfunction scheduled for transurethral resection of prostate, and in those scheduled for transurethral resection of bladder tumor without apparent discomfort during urination. The number of intersections showed a relationship with voiding symptoms. In conclusion, reconstruction of the 3D structure of the prostatic urethra from endoscopic video images is a feasible method that shows promise for estimating the mechanism of voiding dysfunction.

High-resolution three-dimensional endovaginal ultrasonography in the assessment of pelvic floor anatomy: a preliminary study

INTRODUCTION AND HYPOTHESIS

Our aim was to evaluate the morphological characteristics of the female pelvic floor that may be further elucidated with three-dimensional endovaginal ultrasonography (3D-EVUS).

METHODS

A consecutive series of 20 nulliparous females underwent 3D-EVUS. Measurements were determined according to pre-established criteria. Descriptive statistics and Spearman's correlation test were performed.

RESULTS

The levator hiatus (LH) was measured in the oblique plane parallel to the pubovisceral muscle. A positive correlation was found between LH area and age (p = 0.03). The anteroposterior diameter of the urogenital hiatus, measured in the axial plane tilted from the symphysis pubis to the ischiopubic rami, correlated with LH area (p = 0.008). No urethral rotations were observed in the coronal plane. Significant correlations were found among urethral parameters. Mean anal sphincter measurements were comparable to previously reported magnetic resonance imaging and ultrasound measurements.

CONCLUSIONS

3D-EVUS allows measurements of key pelvic floor structures in planes that cannot be determined by conventional imaging modalities.

Urethral sphincter morphology and function with and without stress incontinence

PURPOSE

Using magnetic resonance images we analyzed the relationship between urethral sphincter anatomy, urethral function and pelvic floor function.

MATERIALS AND METHODS

A total of 103 women with stress incontinence and 108 asymptomatic continent controls underwent urethral profilometry, urethral axis measurement with a cotton swab, vaginal closure force measurement with an instrumented speculum and magnetic resonance imaging. Striated urogenital sphincter length was determined and its thickness was measured in the proximal sphincter, where its circular shape enables estimation of striated urogenital sphincter area. A length-area index was calculated as a proxy for volume.

RESULTS

The striated urogenital sphincter in women with stress incontinence was 12.5% smaller than that in asymptomatic continent women (mean +/- SD length-area index 766.4 +/- 294.3 vs 876.2 +/- 407.3 mm(3), p = 0.04). The groups did not differ significantly in striated urogenital sphincter length (13.2 +/- 3.4 vs 13.7 +/- 3.9 mm, p = 0.40), thickness (2.83 +/- 0.8 vs 3.11 +/- 1.4 mm, p = 0.09) or area (59.1 +/- 18.4 vs 62.9 +/- 24.7 mm(2), p = 0.24). Striated urogenital sphincter length and area, and the length-area index were associated during voluntary pelvic muscle contraction with more urethral axis elevation and increased vaginal closure force augmentation.

CONCLUSIONS

A smaller striated urogenital sphincter is associated with stress incontinence and poorer pelvic floor muscle function.

Advances in imaging for urologic procedures

Improvements in imaging and device engineering have led to the rapid development of advanced, minimally invasive techniques in urologic care. While imaging advances have had a major effect in the areas of diagnosis, surgical planning and therapeutic assessment, the focus of this Review is on developments in intraoperative imaging that are currently making an impact in urology and are likely to provide additional opportunities to urologists in the years to come. While previous image-guided urologic procedures have mostly utilized two-dimensional X-ray images, it is expected that new technologies will involve the use of three- and four-dimensional multi-modality imaging, molecular imaging, and robot-assisted image-guidance techniques. Application of these procedures will bring together the complementary disciplines of endourology and interventional radiology in the development of multidisciplinary, cooperative approaches to providing optimal treatments and outcomes for urologic disease.

Three and four-dimensional ultrasound in obstetrics and gynecology

PURPOSE OF REVIEW

Developments in ultrasound in general, but even more so in three-dimensional ultrasound, parallel the growth in computing power and speed of computer technology. It is not surprising, therefore, that three-dimensional ultrasound technology is constantly evolving at a fast pace. The purpose of this article is to provide enhanced diagnostic capabilities for the obstetrical and gynecologic provider.

RECENT FINDINGS

The most recent advances in three-dimensional ultrasound have to do with two main features. First, an increasingly fast acquisition speed, enabling quick sequences of fast moving organs such as the heart to be captured. Second, the increasing number of different display modalities, making understanding and analysis of normal anatomy and pathology easier for clinicians.

SUMMARY

This article highlights a selected number of clinical situations in which three-dimensional ultrasound meaningfully enhances the contribution of this fast evolving diagnostic imaging tool.

Translabial ultrasonography in the assessment of urethral diameter and intrinsic urethral sphincter deficiency

OBJECTIVE

The purpose of this study was to determine the role of translabial ultrasonography in the investigation of intrinsic urethral sphincter deficiency (ISD), assessing bladder neck hypermobility and urethral diameter in continent and incontinent patients.

METHODS

A case-control study evaluated 94 women with the diagnosis of urinary incontinence and 96 continent women. Both groups underwent translabial ultrasonography to assess bladder neck hypermobility by means of the x-y coordinate system and urethral diameter. The study was performed at Hospital de Clínicas de Porto Alegre.

RESULTS

Women with urinary stress incontinence showed significantly greater bladder neck descent than continent women and women with urge and mixed incontinence (P = .05). Women with ISD showed significantly larger urethral diameters than control subjects and incontinent women without ISD (P = .05). Of women with urinary incontinence, 78.7% had descent of greater than 10 mm, and 91.7% of the women with ISD had urethral diameters of greater than 6 mm. A urethral diameter of greater than 6 mm showed sensitivity of 91.7% and specificity of 75.6% for ISD.

CONCLUSIONS

Translabial ultra-sonography has an important role in the assessment of women with urinary stress incontinence and intrinsic urethral sphincter deficiency.