Comparison of transanal and external perineal ultrasonography

Combined 3D Endoanal Ultrasound and Transperineal Ultrasound Improves the Detection of Anal Sphincter Defects

INTRODUCTION

Anal sphincter injury, mainly due to obstetric or iatrogenic etiology, is the most common cause of fecal incontinence (FI). Three-dimensional endoanal ultrasound (3D EAUS) is used for assessment of the integrity and the degree of anal muscle injury. However, 3D EAUS accuracy may be hampered by regional acoustic effects, such as intravaginal air. Therefore, our aim was to examine whether a combination of transperineal ultrasound (TPUS) and 3D EAUS would improve the accuracy of detection of anal sphincter injury.

METHODS

We prospectively performed 3D EAUS followed by TPUS in every patient evaluated for FI in our clinic between January 2020 and January 2021. The diagnosis of anal muscle defects was assessed in each ultrasound technique by two experienced observers that were blinded to each other's assessments. Interobserver agreement for the results of the 3D EAUS and the TPUS exams was examined. A final diagnosis of anal sphincter defect was based on the results of both ultrasound methods. Discordant results were re-analyzed by the two ultrasonographers for a final consensus on the presence or absence of defects.

RESULTS

A total of 108 patients underwent ultrasonographic assessment due to FI (mean age 69 ± 13). Interobserver agreement for the diagnosis of tear on EAUS and TPUS was high (83%) with Cohen's kappa of 0.62. EAUS confirmed anal muscle defects in 56 patients (52%), while TPUS confirmed them in 62 patients (57%). The final consensus agreed on the diagnosis of 63 (58%) muscular defects and 45 (42%) normal exams. The Cohen's kappa coefficient of agreement between the results of the 3D EAUS and the final consensus was 0.63.

CONCLUSIONS

The combination of 3D EAUS and TPUS improved the detection of anal muscular defects. The application of both techniques for the assessment of the anal integrity should be considered in every patient going through ultrasonographic assessment for anal muscular injury.

Assessing Anorectal Function in Constipation and Fecal Incontinence

Constipation and fecal incontinence are commonly encountered complaints in the gastrointestinal clinic. Assessment of anorectal function includes comprehensive history, rectal examination, and prospective stool diary or electronic App diary that accurately captures bowel symptoms, evaluation of severity, and quality of life of measure. Evaluation of a suspected patient with dyssynergic constipation includes anorectal manometry, balloon expulsion test, and defecography. Investigation of a suspected patient with fecal incontinence includes high-resolution anorectal manometry; anal ultrasound or MRI; and neurophysiology tests, such as translumbosacral anorectal magnetic stimulation or pudendal nerve latency. This article provides an approach to the assessment of anorectal function.

Dynamic transperineal ultrasonography correlates with prolonged pudendal nerve latency in female with fecal incontinence

The pelvic floor is a complex anatomical entity and its neuromuscular assessment is evaluated through debated neurophysiological tests. An innovative approach is the study of pelvic floor through dynamic transperineal ultrasound (DTU). The aim of this study is to evaluate DTU sensitivity in recognizing patients with fecal incontinence and to evaluate its concordance with the results of the motor latency studied via pudendal nerve terminal motor latency (PNTML). Female patients affected by FI addressed to our center of coloproctology were prospectively assessed. After a coloproctological evaluation, comprising the PNTML assessment to identify pudendal neuropathy, patients were addressed to DTU to determine anterior and posterior displacement of puborectalis muscle by a blinded coloproctologist. In order to compare the data, a cohort of female healthy volunteers was enrolled. Sixty-eight subjects (34 patients and 34 healthy volunteers) were enrolled. The sensitivities of anterior displacement, posterior displacement and either anterior or posterior displacement in determining the fecal incontinence were 82%, 67% and 91%, respectively. A further high correlation of either anterior or posterior displacement with PTNML was also noted (88%). DTU is an indirect, painless and reproducible method for the identification of the pelvic floor neuromuscular integrity. Its findings seem to highly correlate with FI symptoms and with PNTML results. In the near future, after larger comparative studies, DTU would be considered a potential reliable non-invasive and feasible indirect procedure in the identification of fecal incontinence by pudendal neuropathy. Trial registration number is NCT03933683.

EFSUMB Recommendations for Gastrointestinal Ultrasound Part 3: Endorectal, Endoanal and Perineal Ultrasound

This article represents part 3 of the EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound (GIUS). It provides an overview of the examination techniques recommended by experts in the field of endorectal/endoanal ultrasound (ERUS/EAUS), as well as perineal ultrasound (PNUS). The most important indications are rectal tumors and inflammatory diseases like fistula and abscesses in patients with or without inflammatory bowel disease (IBD). PNUS sometimes is more flexible and convenient compared to ERUS. However, the technique of ERUS is quite well established, especially for the staging of rectal cancer. EAUS also gained ground in the evaluation of perianal diseases like fistulas, abscesses and incontinence. For the staging of perirectal tumors, the use of PNUS in addition to conventional ERUS could be recommended. For the staging of anal carcinomas, PNUS can be a good option because of the higher resolution. Both ERUS and PNUS are considered excellent guidance methods for invasive interventions, such as the drainage of fluids or targeted biopsy of tissue lesions. For abscess detection and evaluation, contrast-enhanced ultrasound (CEUS) also helps in therapy planning.

Three-Dimensional Endoanal Ultrasound Features of the Anal Sphincter in Asian Primigravidae

OBJECTIVES

The normal parameters of 3-dimensional endoanal ultrasound (3DEAUS) of the anal sphincter have not been reported for primigravidae or pregnant women at present. 3DEAUS parameters in Asian primigravidae were assessed in this study.

METHODS

We analyzed 3DEAUS data of 101 consecutives Asian primigravidae, assessed in the early third trimester. The assessment was performed with a rigid ultrasonic probe (Olympus^® RU 12M-R1 probe and EU-ME1 ultrasound system (Olympus Corp., Shinjuku, Japan). The Wilcoxon signed-rank test was used to detect the differences in pressure in different quadrants.

RESULTS

The participants had a mean age of 24.7 (standard deviation [SD], 5.1) years. The Cleveland Clinic Incontinence Score was normal in all participants. The anal sphincter complex had 3 characteristic segments that were identifiable: upper, middle and lower. The puborectalis muscle was identified as a striated "V"-shaped sling, and its mean thickness was 7.44 (SD, 1.41) mm. The mean thickness of internal (IAS) and external (EAS) sphincters at the mid-sphincter level were 1.78 (SD, 0.59) and 5.49 (SD, 1.21) mm, respectively. The EAS measured 6.02 (SD, 1.07) mm at the lower sphincter level. The statistically significant differences seen in the in quadrants were: the IAS was thicker anteriorly (Z = -2.642; P = .008), the EAS at both midsphincter level (Z = -3.70; P < .001) and lower sphincter level (Z = -7.712; P < .001) was thicker posteriorly, and the IAS was thicker at the 9 o'clock position (Z = -2.081; P = .037). Good symmetry at all 3 levels was seen in the EAS (including the puborectalis muscle).

CONCLUSIONS

Normal values of 3DEAUS for primigravidae have been identified and may serve as reference values for other laboratories.

Exoanal Imaging of the Anal Sphincters

Since its introduction in the early 1990s, endoanal sonography has become the mainstay of morphologic assessment of the anal canal and sphincter, especially for obstetric anal sphincter trauma. Lack of availability of suitable systems and the invasive nature of the method have limited uptake and clinical utility. More recently, exoanal or transperineal/translabial tomographic imaging has been developed as a noninvasive alternative. This pictorial overview aims to introduce the reader to this new diagnostic modality and to demonstrate common findings in asymptomatic and symptomatic women.

Particularities of Crohn's disease in pediatric patients: current status and perspectives regarding imaging modalities

A consensus on the best imaging modality evaluating inflammatory bowel disease in the pediatric population is lacking and it is often unclear which modality to choose in specific clinical circumstances. Children with inflammatory bowel disease are exposed to ionizing radiation from multiple imaging studies performed at initial diagnosis, throughout treatment and during the follow-up period. This paper discusses the value of different imaging techniques in pediatric patients with inflammatory bowel disease and gives a review of the literature. In addition, particular features of inflammatory bowel disease in children including the predilection of affected segments in the gastrointestinal tract are highlighted. Based on current literature knowledge, we encourage an integrative approach to the interpretation of clinical and imaging data for diagnosis and follow-up in daily clinical settings.

Correlation of three dimensional anorectal manometry and three dimensional endoanal ultrasound findings in primi gravida: a cross sectional study

Background

3-dimensional anorectal manometry (3DARM) and 3-dimensional endoanal ultrasound (3DEAUS) have not been used to assess the anal sphincter complex (ASC) in primi gravida. This study was conducted to identify any correlation that may exist between 3DARM and 3DEAUS.

Methods

We analyzed 3DARM and 3DEAUS data of 101 consecutive primi mothers assessed in the late second trimester or early 3rd trimester. 3DARM was performed using the Given Imaging^® Manoscan system and 3DEAUS was performed with the Olympus^® RU 12M-R1 probe and EU-ME1 ultrasound system.

Results

The mean age was 24.7 (SD—5.1) years. All patients had a normal Cleveland Clinic Incontinence Score. The mean resting pressure (RP) was 87.02 (SD—18.43) mmHg and the maximum squeeze pressure (SP) was 179.21 (SD—52.96) mmHg. The mean length of the high pressure zone was 3.67 (SD—0.52) cm. On 3DEAUS, there were three characteristic segments of the ASC that were identified; upper, middle and lower. Mean thicknesses for both internal anal sphincter (IAS) and external anal sphincter (EAS) were identified for primi gravida. IAS was thicker anteriorly and at 9 o’ clock positions and EAS was thicker posteriorly. There was good correlation in the length of the ASC at each quadrant between 3DARM and 3DEAUS. There was no correlation between either RP or SP thickness of IAS or EAS at each level and quadrant.

Conclusion

Correlation is seen only in the length of ASC at each quadrant. No correlation exist between RP or SP and thickness of IAS and EAS.

Transperineal sonographic anal sphincter complex evaluation in chronic anal fissures

OBJECTIVES

The purpose of this study was to assess the role of transperineal sonography in assessment of pathologic changes to the anal sphincter complex in patients with chronic anal fissures.

METHODS

We conducted a prospective case-control study of 100 consecutive patients of any age and both sexes with chronic anal fissures who presented to a colorectal clinic between January 2012 and August 2013 (group A) and 50 healthy volunteers (group B).

RESULTS

The most common patterns of radiologic changes to anal sphincters associated with chronic anal fissures were circumferential thickening of the anal sphincter complex in 5 patients (5%), circumferential thickening of the internal anal sphincter in 3 patients (3%), preferential thickening of the internal anal sphincter at the 6-o'clock position in 80 patients (80%) and the 12-o'clock position in 7 patients (7%), preferential thickening of the internal and external anal sphincters in 3 patients (3%), and thinning of the internal anal sphincter in 2 patients (2%).

CONCLUSIONS

Chronic anal fissures cause differential thickening of both internal and external anal sphincters, with a trend toward increased thickness in relation to the site of the fissure. Routine preoperative transperineal sonography for patients with chronic anal fissures is recommended, and it is mandatory in high-risk patients.

Anal sphincter complex: 2D and 3D endoanal and translabial ultrasound measurement variation in normal postpartum measurements

INTRODUCTION AND HYPOTHESIS

Women may experience anal sphincter anatomy changes after vaginal birth (VB) or Cesarean delivery (CD). Therefore, accurate and acceptable imaging options to evaluate the anal sphincter complex (ASC) are needed. ASC measurements may differ between translabial (TLUS) and endoanal (EAUS) ultrasound imaging and between 2D and 3D US. The objective of this analysis was to describe measurement variation between these modalities.

METHODS

Primiparous women underwent 2D and 3D TLUS imaging of the ASC 6 months after VB or CD. A subset of women also underwent EAUS measurements. Measurements included internal anal sphincter (IAS) thickness at proximal, mid, and distal levels and the external anal sphincter (EAS) at 3, 6, 9, and 12 o'clock positions, as well as bilateral thickness of the pubovisceralis muscle (PVM).

RESULTS

There were 433 women presenting for US: 423 had TLUS and 64 had both TLUS and EAUS of the ASC. All IAS measurements were significantly thicker on TLUS than EAUS (all p < 0.01), while EAS measurements were significantly thicker on EAUS (p < 0.01). PVM measurements with 3D or 2D imaging were similar (p > 0.20). On both TLUS and EAUS, there were multiple sites where significant asymmetry existed in left versus right measurements.

CONCLUSIONS

US modality used to image the ASC introduces small but significant changes in measurements, and the direction of the bias depends on the muscle and location being imaged.

Usefulness of 3D transperineal ultrasound in severe stenosis of the anal canal: preliminary experience in four cases

Background

Organic or functional anal canal stenoses are uncommon conditions that occur in the majority of cases as a consequence of anal diseases. A proper assessment is fundamental for decision making; however, proctological examination and endoanal ultrasound are often unfeasible or very difficult to perform even under local or general anesthesia. We therefore began to use 3D transperineal ultrasound to assess patients. The aim of this study was to compare the results of evacuation proctography and 3D transperineal ultrasound in patients with severe anal canal stenosis.

Methods

Four consecutive patients with high-grade anal canal stenosis were evaluated using both proctography and 3D transperineal ultrasound with a micro-convex transducer between March and June 2011.

Results

In all cases, 3D transperineal ultrasound provided detailed information on the length and level of stenosis and on the integrity of the anal sphincters.

Conclusions

Our preliminary experience suggests that 3D transperineal ultrasound makes it possible to plan optimal surgical treatment.

Ultrasound imaging of the anal sphincter complex: a review

Endoanal ultrasound is now regarded as the gold standard for evaluating anal sphincter pathology in the investigation of anal incontinence. The advent of three-dimensional ultrasound has further improved our understanding of the two-dimensional technique. Endoanal ultrasound requires specialised equipment and its relative invasiveness has prompted clinicians to explore alternative imaging techniques. Transvaginal and transperineal ultrasound have been recently evaluated as alternative imaging modalities. However, the need for technique standardisation, validation and reporting is of paramount importance. We conducted a MEDLINE search (1950 to February 2010) and critically reviewed studies using the three imaging techniques in evaluating anal sphincter integrity.

Clinical relevance of transperineal ultrasound compared with evacuation proctography for the evaluation of patients with obstructed defaecation

AIM

Dynamic evacuation proctography (DEP) is still considered the gold standard diagnostic procedure for posterior compartment pelvic disorders. The study aimed to assess the value of dynamic transperineal ultrasound (DTPU) compared with DEP in patients with obstructed defaecation syndrome (ODS).

METHOD

In a prospective observational study, 54 consecutive female patients referred with symptoms of ODS between January and June 2009 were studied by clinical evaluation (including Wexner score), perineal ultrasound and defaecography. The tests were analysed by two experienced investigators unaware of the opinion of the other.

RESULTS

DEP revealed a rectocoele in 35 (64%), intussusception in 27 (50%) and enterocoele in 10 (18.5%) patients. DTPU revealed a rectocoele in 32 (59%), intussusception in 23 (42%) and enterocoele in 11 (20%) patients. The degree of agreement of the two techniques calculated using the Cohen kappa method was 0.69 for rectocoele, 0.74 for intussusception and 0.86 for enterocoele. In patients with grade 2-3 rectocoele, the agreement was 0.88. There was no significant difference between the two techniques in the measurement of the anorectal angle or in the detection of dyssynergic contraction of the puborectalis. DTPU was better at identifying multiple diagnoses and associated pelvic floor alterations.

CONCLUSION

The degree of concordance between the two techniques is good. DTPU is accurate for asymptomatic patients with ODS and can be considered an alternative to DEP in the assessment of such patients.

Accuracy of measurement of puborectal contraction by perineal ultrasound in patients with faecal incontinence

AIM

The study aimed to determine the accuracy of measurement of puborectal contraction, measured by perineal ultrasound during anal voluntary contraction in patients with incontinence.

METHOD

Puborectalis sling contraction in 32 consecutive patients investigated for faecal incontinence was determined by two examiners on two occasions (four measurements per patient). The examiners were blinded to each other's results.

RESULTS

The mean anterior movement of the puborectalis sling was between 11 and 12 mm for both examiners on both occasions. The global intraclass correlation coefficient for examiners and occasions together was 0.92. The absolute agreement on the movement exceeding or not 8 mm was 87.5% (28 of 32), and the corresponding κ statistic was 0.84. The differences between the two experts were minimal.

CONCLUSION

The study confirms the reliability of puborectalis sling contraction measurement and its value as a preoperative predictive tool to assess the prognosis of sphincter repair for postdelivery faecal incontinence.

The diagnostic accuracy of endovaginal and transperineal ultrasound for detecting anal sphincter defects: The PREDICT study. Clin Radiol. 2011;66:597-604. [PMID: 21440249 DOI: 10.1016/j.crad.2010.11.017]

AIM

To determine the accuracy and predictive value of transperineal (TPU) and endovaginal ultrasound (EVU) in the detection of anal sphincter defects in women with obstetric anal sphincter injuries and/or postpartum symptoms of faecal incontinence.

MATERIALS AND METHODS

One hundred and sixty-five women were recruited, four women were excluded as they were seen years after their last delivery. TPU and EVU, followed by endonanal ultrasound (EAU), were performed using the B&K Viking 2400 scanner. Sensitivity and specificity, as well as predictive values with 95% confidence intervals, for detecting anal sphincter defects were calculated for EVU and TPU, using EAU as the reference standard.

RESULTS

On EAU a defect was found in 42 (26%) women: 39 (93%) had an external (EAS) and 23 (55%) an internal anal sphincter (IAS) defect. Analysable images of one level of the EAS combined with an analysable IAS were available in 140 (87%) women for EVU and in 131 (81%) for TPU. The sensitivity and specificity for the detection of any defect was 48% (30-67%) and 85% (77-91%) for EVU and 64% (44-81%) and 85% (77-91%) for TPU, respectively.

CONCLUSION

Although EAU using a rotating endoprobe is the validated reference standard in the identification of anal sphincter defects, it is not universally available. However while TPU and/or EVU with conventional ultrasound probes can be useful in identifying normality, for clinical purposes they are not sensitive enough to identify an underlying sphincter defect.

Transperineal ultrasound in the assessment of haemorrhoids and haemorrhoidectomy: a pilot study

BACKGROUND

The purpose of the study was the measurement of the anal cushion area using static transperineal ultrasound in a group of patients with symptomatic grade III and IV haemorrhoids about to undergo haemorrhoidectomy and compare them with a group of age-matched normals and the measured area following haemorrhoidectomy.

METHODS

Transperineal sonography was performed using a linear transducer measuring the anal cushion area by subtracting the measured luminal diameter of the undisturbed anal canal from the inner border of the internal anal sphincter. Measures were made 6 weeks following haemorrhoidectomy.

RESULTS

Comparisons were made between 22 normals and 36 patients with haemorrhoids (31 evaluable post-operatively). The median area of normals was 0.78 cm², that of pre-operative patients 2.25 cm² and that of post-operative cases 1.20 cm². There was a significant difference between pre- and post-operative cases with cushion areas of normal patients being significantly lower than post-operative cases. Variance of measurement in all 3 groups was negligible.

CONCLUSION

Static transperineal sonography measuring the anal cushion area is reproducible and shows marked differences between normals and patients with symptomatic haemorrhoids. There is a marked effect on measured area resultant from haemorrhoidectomy.

Dynamic magnetic resonance imaging and transperineal sonography in the assessment of patients presenting primarily with evacuatory difficulty: a short position paper

Patients presenting with primary evacuatory difficulty have a multiplicity of pelvic floor and perineal soft tissue anomalies. The radiological assessment of these patients requires modalities which monitor the dynamic interaction of pelvic organs during provocative manoeuvres such as straining and simulated defaecation. The advantages and disadvantages of these complementary modalities, (dynamic magnetic resonance imaging, dynamic transperineal sonography and dynamic 2- and 3-dimensional endoanal sonography) are provided in this position paper.

Sonographic assessments of gastrointestinal and biliary functions

Ultrasound has been established as a routine work-up imaging method in abdominal diseases. It assesses the morphology of intra-abdominal organs and depicts the normal and pathological anatomy of the gastrointestinal tract as well as of the biliopancreatic system. Ultrasound is the method of choice for visualisation of motion sequences since it is, in contrast to other imaging methods, a real-time method. The non-invasiveness and the repeatability of the method are important advantages when performing investigations of functional processes. Therefore, ultrasound is most suited for functional studies. Up to now, functional ultrasound and its potential have been undervalued. Functional ultrasound provides a widely available method to increase our understanding of functional processes and motility. The authors review the options of functional ultrasound and discuss its practical relevance.

Measure of the voluntary contraction of the puborectal sling as a predictor of successful sphincter repair in the treatment of anal incontinence

PURPOSE

Overlapping sphincteroplasty is the surgery of choice for incontinent patients with an anterior defect after childbirth. Numerous predictive factors have been proposed, but no preoperative variables have been successfully shown to be reproducible. The purpose of this study was to assess the prognostic value of voluntary contraction of the puborectal sling before sphincter repair for anal incontinence.

METHODS

This prospective study evaluated 109 consecutive women who underwent surgery for postobstetric anal incontinence. Voluntary contraction of the puborectal sling was measured by perineal ultrasound before the surgery. Severity of anal incontinence was evaluated preoperatively and postoperatively with the Miller Incontinence Score (total incontinence = 18, complete continence = 0).

RESULTS

The proportion of patients with scores <or=3 was 16.7 percent when the preoperative voluntary contraction of the puborectal sling was <or=4 mm, 48.1 percent when it was 4.1 to 8 mm, and 98.7 percent when it was >8 mm (P < 0.001). Using <or=8 mm to define abnormal shortening, the sensitivity of the test was 0.95 (95 percent confidence interval, 0.75-1.00) and specificity was 0.84 (95 percent confidence interval, 0.75-0.91).

CONCLUSION

A preoperative voluntary contraction of the puborectal sling >8 mm convincingly discriminates between patients with a good functional outcome and those with an unsatisfactory outcome after sphincter repair for postobstetric anal incontinence.

Ultrasonographic anatomy of perineal structures during pregnancy and immediately following obstetric injury

OBJECTIVES

To assess perineal anatomy using ultrasound before and immediately after delivery.

METHODS

Structures in the perineum were studied by real-time two-dimensional transvaginal and endoanal ultrasound imaging using a combined linear and semicircular (up to 200 degrees sector) probe. We examined 45 nulliparous pregnant women and 44 primiparae immediately after delivery (40 with anal sphincter tears and four without sphincter injury). In each case a single longitudinal image was later assessed by two observers in order to evaluate interobserver agreement.

RESULTS

In pregnancy, the perineal membrane, puboperineal muscles, conjoined longitudinal muscle and central point were identified on real-time examination in 91%, 98%, 100% and 100% of cases, respectively. At offline evaluation of the longitudinal images obtained for each of the pregnant women, the percentage of cases in which each structure was identified by both observers ranged from 64% to 100%. In the women who were examined postpartum, all structures were identified by both observers in all four of the women without sphincter injury. In the women with sphincter tears, the perineal membrane, puboperineal muscles, conjoined longitudinal muscle and central point were found by ultrasound to be intact in 10%, 10%, 55% and 18%, respectively. The agreement between two observers regarding identification of intact structures in a single longitudinal image was good for perineal membrane (kappa index, 0.66), fair for puboperineal muscles (kappa index, 0.40), and poor for conjoined longitudinal muscle and central point (kappa index, 0.08 and 0.17, respectively).

CONCLUSIONS

Ultrasonography might be helpful in the evaluation of perineal anatomy and extent of perineal tears. However, the relatively poor agreement between the two observers evaluating single linear transvaginal images implies that both transverse and longitudinal projections are necessary to obtain relevant information. Further studies are needed regarding the importance of specific sonographically identified structures and their role in pelvic floor dysfunction after delivery.

Sonographic visualization of the rectoanal inhibitory reflex in children suspected of having Hirschsprung disease: a pilot study

OBJECTIVE

To date, for detection of the absence of peristalsis in children with chronic constipation and a suspicion of Hirschsprung disease (HD), children have been investigated with a contrast enema. If the radiographic investigation is inconclusive, anometry and a rectal biopsy are performed. A new noninvasive real-time sonographic method for examination of the rectoanal inhibitory reflex (RAIR) was compared with anometry.

METHODS

The rectum and anal canal of children were visualized transperineally on sonography. The RAIR was elicited by injecting water into the rectum, and the events in the bowel were recorded on video for offline analysis.

RESULTS

Injection of water initiated a peristaltic wave that moved the rectal contents into the proximal part of the anal canal in healthy children. Among 28 children with suspected HD, 3 showed aganglionosis in their biopsy samples. These 3 children lacked the RAIR according to both sonography and anometry. Both methods had a negative predictive value of 100%. In 17 children, the RAIR was present according to both sonography and anometry, and all of these children had normal histologic findings. In 8 children, sonography did not show the reflex despite normal histologic findings; in 2 of these, the quality of the investigation made the evaluation uncertain.

CONCLUSIONS

This pilot study indicates that in children with chronic constipation, a transperineal sonographic examination of the RAIR is comparable to anometry and can facilitate the diagnose of HD.

Delivery method, anal sphincter tears and fecal incontinence: new information on a persistent problem

PURPOSE OF REVIEW

To review the risk factors for anal sphincter tears during vaginal delivery and their association with fecal incontinence symptoms.

RECENT FINDINGS

Recent evidence links sphincter tears with fecal incontinence, which has a significant negative impact on quality of life. The Childbirth and Pelvic Symptoms cohort study reported that the incidence and severity of fecal incontinence was increased in primiparous women experiencing a sphincter tear. Risk factors for tear included forceps, occiput posterior, vacuum delivery, prolonged second stage of labor and epidural. Using cesarean delivery to prevent fecal incontinence has not been justified, but the confluence of these risk factors in the context of labor management may be important in deciding on earlier intervention with cesarean delivery. Internal anal sphincter defects impact fecal incontinence, highlighting the identification and repair of the internal anal sphincter for future research and clinical applications. Routine episiotomy (or instrumentation) is not warranted, and there is no clear advantage to mediolateral episiotomy or overlapping sphincter repair. Postpartum ultrasound of the sphincter complex may have an emerging role.

SUMMARY

The modifiable risk factors of routine episotomy and instrumented delivery are associated with sphincter tear; definitive recommendations for labor management remain unclear in preventing fecal incontinence.

The role of transperineal ultrasonography in the assessment of the internal opening of cryptogenic anal fistula

PURPOSE

The aim of this study was to assess the reliability of transperineal ultrasonography (TPUS) in the pre-operative identification of the internal opening of anal fistulas compared to conventional proctological examination and operative findings.

METHODS

Forty-three patients with anal fistula were assessed by TPUS with and without the use of hydrogen-peroxide injection (E-TPUS) in an attempt to identify the internal opening. Results were compared to preoperative conventional examination and operative findings.

RESULTS

Operative assessment showed an anterior internal opening in 29 patients (67.4%) and a posterior opening in 14 (32.6%). Compared to the operative findings, the agreement rate for the identification of the internal opening was 74.4% for physical examination alone, 93.0% for TPUS and 90.7% for E-TPUS. Physical examination was less accurate in detecting the internal opening than both TPUS (p=0.014) and E-TPUS (p=0.026).

CONCLUSIONS

TPUS and E-TPUS are superior to physical examination in the identification of internal openings in anal fistulas. Hydrogen peroxide injection does not provide additional advantages.

Sonographic assessment of splanchnic arteries and the bowel wall

The intestinal wall can be visualized using high resolution transabdominal ultrasound. The normal intestinal wall thickness in the terminal ileum, cecum, and right and left colon is <2mm when examined with graded compression. It is important to appreciate that a contracted intestinal segment can be misinterpreted as a thickened wall. Vascularisation can be mainly displayed in the second hyperechoic layer (submucosal layer) as well as vessels penetrating the muscularis propria. Imaging of the gastrointestinal wall is dependent on the experience of the examiner as well dependent on the equipment used. Acute or chronic inflammation of the intestinal wall is accompanied by increased perfusion of the mesentery, which can be displayed non-quantitatively with colour duplex. In contrast, ischemia is characterised by hypoperfusion of the mesenteric arteries and the bowel wall. The most promising sonographic approach in assessing splanchnic arteries and the bowel wall is combining the analysis of superior and inferior mesenteric inflow by pulsed Doppler scanning (systolic and diastolic velocities, resistance index) with the end-organ vascularity by colour Doppler imaging diminishing the influence of examination technique only displaying bowel wall vascularity. Colour Doppler imaging has been described as helpful in a variety of gastrointestinal disorders, particularly in patients with Crohn's disease, celiac disease, mesenteric artery stenosis and other ischemic gastrointestinal diseases, graft versus host disease and hemorrhagic segmental colitis.

The clinical significance of postpartum transperineal ultrasound of the anal sphincter

BACKGROUND AND OBJECTIVE

To evaluate the clinical significance of postpartum anal sphincter damage by transperineal ultrasonography (TPUS) performed on the day of delivery.

METHODS

Continence questionnaires were handed out and TPUS was performed on 154 consecutive primiparous women 6-24h after vaginal delivery. At 2 and 6 months later, complaints and sphincteric sonographic appearance were reassessed. The puerperal women's clinical status and sonographic findings in the immediate and late postpartum period were evaluated.

RESULTS

Thirty-five (23%) women complained of anal incontinence on the first postpartum day and anal sphincter damage was demonstrated by TPUS in 31 (89%) of them. Four women with anorectal complaints had an intact anal sphincter by TPUS. Follow-up questionnaires, 2 months later, revealed 30 symptomatic women: all of them had sonographically recognized tears on the initial TPUS and 27 of them had positive findings on the TPUS performed 2 months after birth. Six months after delivery, 27 women reported symptoms and all of them had sphincteric disruption evidenced on TPUS performed on the day of delivery. All the women with intact sphincter on the initial TPUS were asymptomatic 6 months later.

CONCLUSION

TPUS findings on the day of delivery are related to long-term anorectal complaints, supporting a potential role for TPUS as a screening aid for anal sphincter tears.

Ultrasonographic patterns in patients with obstructed defaecation

BACKGROUND

Anal ultrasound is helpful in assessing organic anorectal lesions, but its role in functional disease is still questionable. The purpose of the present study is to assess anal-vaginal-dynamic perineal ultrasonographic findings in patients with obstructed defecation (OD) and healthy controls.

MATERIALS AND METHODS

Ninety-two consecutive patients (77 women; mean age 51 years; range 21-71) with symptoms of OD were retrospectively evaluated. All patients underwent digital exploration, endoanal and endovaginal ultrasound (US) with rotating probe. Forty-one patients underwent dynamic perineal US with linear probe. Anal manometry and defaecography were performed in 73 and 43 patients, respectively. Ultrasonographic findings of 92 patients with symptoms of OD were compared to 22 healthy controls. Anismus was defined on US when the difference in millimetres between the distance of the inner edge of the puborectalis muscle posteriorly and the probe at rest and on straining was less then 5 mm. Sensitivity and specificity were calculated by assuming defaecography as the gold standard for intussusception and rectocele and proctoscopy for rectal internal mucosal prolapse. Since no gold standard for the diagnosis of anismus was available in the literature, the agreement between anal US and all other diagnostic procedures was evaluated.

RESULTS

The incidence of anismus resulted significantly higher (P < 0.05) in OD patients than healthy controls on anal (48 vs 22%), vaginal (44 vs 21%), and dynamic perineal US (53 vs 22%). A significantly higher incidence of rectal internal mucosal prolapse was observed in OD patients when compared to healthy controls on both anal (61.9 vs 13.6%, P < 0.0001) and dynamic perineal US (51.2 vs.9% P = 0.001). For the diagnosis of rectal internal mucosal prolapse, anal US had a 100% sensitivity and specificity. For diagnosis of rectal intussusception, anal US had an 83.3% sensitivity and 100% specificity and perineal US had a 66.6% sensitivity and 100% specificity. In the diagnosis of anismus, anal ultrasonography resulted in agreement with perineal and vaginal US, manometry, defaecography, and digital exam (P < 0.05). Other lesions detected by US in patients with OD include solitary rectal ulcer, rectocele and enterocele. Damage of internal and/or external sphincter was diagnosed at anal US in 19/92 (20%) patients, all continent and with normal manometric values.

CONCLUSION

Anal, vaginal and dynamic perineal ultrasonography can diagnose or confirm many of the abnormalities seen in patients with OD. The value of the information obtained by this non-invasive test and its role in the diagnostic algorithm of OD is yet to be defined.

Translabial ultrasound assessment of the anal sphincter complex: normal measurements of the internal and external anal sphincters at the proximal, mid-, and distal levels

The purpose of this study was to measure the internal and external anal sphincters using translabial ultrasound (TLU) at the proximal, mid, and distal levels of the anal sphincter complex. The human review committee approval was obtained and all women gave written informed consent. Sixty women presenting for gynecologic ultrasound for symptoms other than pelvic organ prolapse or urinary or anal incontinence underwent TLU. Thirty-six (60%) were asymptomatic and intact, 13 symptomatic and intact, and 11 disrupted. Anterior-posterior diameters of the internal anal sphincter at all levels and the external anal sphincter at the distal level were measured in four quadrants. Mean sphincter measurements are given for symptomatic and asymptomatic intact women and are comparable to previously reported endoanal MRI and ultrasound measurements.

Sonographic characteristics of rectal sensations in healthy females

PURPOSE

This study was designed to characterize rectal sensations by visualizing the internal and external anal sphincter and intra-anal transport of bolus during elicited rectal sensations.

METHODS

The anal canal was visualized with real-time transperineal ultrasonography in 13 healthy female volunteers. Rectal sensations were elicited by injecting water into the rectum. The ultrasound images were recorded on a videotape and analyzed offline.

RESULTS

The median time between an injection of water and the events studied was calculated in 105 rectal sensations. A relaxation in the internal anal sphincter (4 seconds after the injection of water), an antegrade transport of bolus (4 seconds) into the anal canal, and a contraction in the external anal sphincter (5 seconds) were observed before a sensation (6 seconds) was reported. The antegrade flow continued until the distal internal anal sphincter contracted (18 seconds) and the bolus moved in a retrograde transport direction (17 seconds) thereafter the sensation disappeared (18 seconds) and the external anal sphincter relaxed (22 seconds). A significant correlation in time between the end of the sensation, contraction in the internal anal sphincter, reversed flow of anal contents, and relaxation of the external anal sphincter was found (Pearson, P<0.01).

CONCLUSIONS

The results verified that the internal anal sphincter contributes to the perception of rectal sensations by a relaxation allowing intra-anal bolus to increase the pressure on the anoderm during rectal contraction. A new observation is presented on the time relation between contraction in the distal internal anal sphincter, reversed flow in the anal canal, and the end of rectal sensations.

Sonographic investigation of the rectoanal inhibitory reflex: a qualitative pilot study in healthy females

PURPOSE

The rectoanal inhibitory reflex has been studied using various methods, e.g., anometry and electromyography. The aim of this study was to apply ultrasound for direct visualization of the rectoanal inhibitory reflex.

METHOD

The rectoanal inhibitory reflex was induced in ten healthy females (age range, 21-55 years) by injection of small amounts of water (7, 12, and 20 ml), into the rectum. The intra-anal pressure was measured with a microtransducer and the rectoanal inhibitory reflex was visualized with real-time transvaginal or transperineal sonography.

RESULTS

The rectoanal inhibitory reflex consisted of a reduction in the intra-anal pressure and relaxation of the internal anal sphincter, manifested as an increase in the inner diameter of the internal anal sphincter from the mean of 11 to 16 mm (P<0.001). Simultaneously, a wave of rectal contents entered the anal canal. The distance from the most distal border of the rectal contents to the anal verge decreased from a mean of 33 to 20 mm (P<0.001). The rectoanal inhibitory reflex ended with a retrograde transport returning anal contents into the rectum. During the retrograde transport a contraction in the internal anal sphincter was observed.

CONCLUSIONS

The rectoanal inhibitory reflex can readily be visualized with ultrasound as a wave of rectal contents entering the anal canal. The transport into the anal canal was not of voluntary origin and could be either noticed or not noticed by the subjects. The observed retrograde transportation in the anal canal was not noted by the subjects; it is related to a contraction in the internal anal sphincter and visualized for the first time using ultrasound.

Simple ultrasound evaluation of the anal sphincter in female patients using a transvaginal transducer

OBJECTIVE

Fecal incontinence affects 0.2% of women aged 15-64 years and about 1.3% of women over 64 years. Most cases are related to instrumental deliveries affecting the anal sphincter complex. We propose a simple technique using the generally available transvaginal transducer to evaluate the anal sphincter complex.

METHODS

Ninety-two patients underwent ultrasound examination. Group I consisted of 53 nulliparous patients. In Group II there were six patients with normal spontaneous vaginal deliveries without episiotomies. In Group III there were 14 patients with vaginal deliveries and one to three episiotomies but no lacerations. In Group IV there were nine postpartum patients with recently repaired (48 h to 3 weeks) third- and fourth-degree lacerations. All women in Groups I-IV were asymptomatic. Group V consisted of 10 patients symptomatic for fecal incontinence. We used a vaginal probe (5-9-MHz) with the footprint placed in the fourchette pointing towards the anus in a transverse and then in a median (sagittal) plane. If seen, the combined internal and external anal sphincter thickness at the 12 o'clock location was measured. We visualized normal star-shaped mucosal folds on the transverse section and described the sonographic anatomy in both planes.

RESULTS

The mean sphincter thickness measured at 12 o'clock in Group I was 2.3 (range, 1.0-4.7) mm, in Group II it was 2.9 (range, 2.4-3.4) mm, and in Group III it was 2.3 (range, 1.0-3.7) mm. The differences between these three groups were not significant. Patients from Group IV showed thinning or discontinuous sphincter anatomy at the 12 o'clock position. All symptomatic patients from Group V showed abnormal sphincter anatomy, and the normal star-like appearance of the anal mucosa on the transverse section was deformed, radiating from the point of the sphincter damage. Four of the 10 patients in this group underwent surgical repair. In these patients the sonographic findings were confirmed.

CONCLUSIONS

The images obtained using this imaging modality show the sphincter muscle anatomy as well as the possible pathology. Due to its simplicity the technique can be applied in any place where a vaginal transducer is available.

Transcutaneous perianal sonography: A sensitive method for the detection of perianal inflammatory lesions in Crohn’s disease

AIM: Pelvic magnetic resonance imaging (MRI) and endoanal ultrasound which are established imaging methods for perianal inflammatory lesions in patients with Crohn’s disease require expensive specialized equipments and expertise. We investigated the feasibility and sensitivity of transcutaneous perianal ultrasound (PAUS) using regular ultrasound probes in the imaging of perianal inflammatory lesions. The sonographic findings were correlated to pelvic MRI-scans.

METHODS: We performed PAUS in 25 patients with Crohn’s disease and clinical signs of perianal inflammatory disease. Within a median of 10 d (range 0-75) these patients underwent MRI of the pelvis. Regular convex and linear high resolution probes were used for PAUS. The sonographic findings were correlated to the MRI findings by blinded investigators.

RESULTS: The sonographic investigations were well tolerated by all patients. Fistulae typically presented as hypoechoic tracks. Twenty-nine fistulae were detected in 22 patients. Abscesses were detected in 7 patients and presented as hypo- or anechoic formations. Twenty-six of 29 fistulae and 6 of 7 abscesses could be confirmed by MRI. Kappa statistics showed an excellent agreement (kappa > 0.83) between the two imaging methods.

CONCLUSION: PAUS is a simple, painless, feasible, real-time method that can be performed without specific patient preparation which is comparable in its sensitivity to pelvic MRI in the detection of perianal fistulae and/or abscesses. PAUS can especially be recommended as a screening tool in acute perianal disorders such as perianal abscess and for follow-up studies of perianal inflammatory disease.

Anal endosonography and its role in assessing the incontinent patient

Anal endosonography is now recognized as an important investigation in the assessment of faecal incontinence. The endosonographer needs to be aware that the anatomy of the anal sphincter is complex and therefore there can be pitfalls in the interpretation of images. The findings have clinical implications on subsequent management and can contribute to prognosticating outcome. However, anal endosonography has a complementary role and other investigations, such as anal manometry, should be performed before intervention.

Detection and characterization of perianal inflammatory disease: accuracy of transperineal combined gray scale and color Doppler sonography

OBJECTIVE

To evaluate the accuracy of transperineal gray scale and color Doppler sonography for the detection and characterization of perianal inflammatory disease with surgical correlation.

METHODS

Eighty-seven patients with suspected perianal inflammatory disorders underwent transperineal gray scale and color Doppler sonography with a linear 4- to 7-MHz transducer that was used to scan the entire perianal region for the detection of suspected inflammatory disorders. Each detected inflammatory disorder was evaluated to determine its morphologic characteristics and extent. Color Doppler sonography was applied to assess the presence of increased vascularity in the perianal region. In comparison with surgical findings, the diagnostic performance of transperineal sonography was assessed by means of receiver operating characteristic analysis for lesion detection and the Spearman rho test for lesion characterization. Logistic regression analysis was used to assess whether increased perineal vascularity was a predictive factor of perianal inflammatory disease.

RESULTS

Seventy-seven perianal inflammatory disorders were confirmed in 62 patients. Gray scale sonography achieved a significantly good performance in the detection (area under the curve = 0.86; P < .001) and characterization (r = 0.65; P < .001) of perianal inflammatory disease. For the detection of perianal fistulas and abscesses, sensitivity was 100% for both, and specificity was 100% and 94%, respectively. With the use of color Doppler sonography, the diagnostic confidence increased slightly (area under the curve = 0.89) but significantly (P = .002). Logistic regression analysis identified hypervascularity at the periphery of a perianal lesion as a significant independent predictor of an inflammatory disease.

CONCLUSIONS

Combined gray scale and color Doppler sonography enables a high detectability rate and comprehensive characterization of perianal abscesses and fistulas.