Endoanal ultrasound in benign anorectal disorders: clinical relevance and possibilities

[Postpartum fecal incontinence. State of the problem]

A review of the current national and foreign literature is devoted to epidemiology, risk factors, causes, diagnosis and modern treatment approaches for fecal incontinence (FI). Incidence of FI in early and delayed period after childbirth is 30% or more. At the same time, up to 87% of postpartum injuries of anal sphincter remain undiagnosed. Importantly, routine caesarean section does not reduce the risk of incontinence. In addition to typical complaints of spontaneous gas and stool, diagnosis of FI after childbirth includes transrectal ultrasound, MRI, anorectal manometry and pudendal nerve terminal motor latency testing. Survey of proctologists from different regions of Russia revealed a high demand from medical community for educational programs devoted to diagnosis, treatment and rehabilitation of patients with postpartum perineal injuries.

What is a significant defect of the anal sphincter on translabial ultrasound?

OBJECTIVE

The anal sphincter is commonly evaluated with endoanal ultrasound. Recently, translabial ultrasound imaging has been proposed for sphincter imaging, with moderate to good correlation between the methods. An endosonographic defect is defined as one with a radial extension of > 30° in at least two-thirds of the length of the anal sphincter. This is equivalent to defining significant anal sphincter trauma on translabial tomographic ultrasound imaging (TUI) as a defect in at least four of six slices, a definition which has been validated. This study was designed to validate a residual defect angle of > 30° for the definition of significant anal sphincter trauma on translabial ultrasound.

METHODS

This was a retrospective study involving 399 women attending a tertiary urogynecology unit in 2014. All underwent a standardized interview, including determination of St Mark's fecal incontinence score (SMIS), clinical examination and 3D/4D translabial ultrasound examination with the woman at rest and on pelvic floor muscle contraction (PFMC). External (EAS) and internal (IAS) anal sphincter defect angles were measured in individual TUI slices and associations with anal incontinence symptoms, bother score and SMIS were analyzed.

RESULTS

There were weak but significant correlations of anal incontinence symptoms, bother score and SMIS with EAS and IAS defect angle, measured on images acquired with the woman at rest and on PFMC. The predictive value of single-slice defect angle on TUI was low, and areas under the receiver-operating-characteristics curves were too low to determine a distinct cut-off value for defect angle.

CONCLUSIONS

Anal sphincter residual defects on single translabial TUI slices are weakly associated with measures of anal incontinence. Single-slice defect angle is too poor a predictor to allow validation of the 30° defect angle cut-off used in endoanal ultrasound. Larger studies in populations with a higher prevalence of anal incontinence are needed before we can disregard anal sphincter defects smaller than 30° on translabial ultrasound. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Rectal Endoscopic Ultrasound in Clinical Practice

PURPOSE OF REVIEW

Endoscopic ultrasound (EUS) is routinely utilized for evaluation of disorders of the lower gastrointestinal tract. In this review, we summarize the current status of rectal EUS in clinical practice and describe recent developments in diagnostic and therapeutic rectal EUS.

RECENT FINDINGS

Recent guidelines recommend rectal EUS for rectal cancer staging as a second line modality in cases where MRI is contraindicated. Forward-viewing echoendoscopes and through the scope EUS miniprobes allow for EUS imaging of lesions through the entire colon and for evaluation beyond stenoses or luminal narrowings. EUS can be used to assess perianal disease and drain pelvic abscess associated with IBD, along with newer applications currently under investigation. For rectal varices, EUS can confirm the diagnosis, assess the optimal site for banding, guide therapy placement with sclerotherapy and/or coils, and assess response to treatment by confirming absence of flow. Therapeutic rectal EUS is emerging as a promising modality for drainage of pelvic fluid collection drainage and fiducial placement for rectal or prostatic cancer. Drug delivery mechanisms and substances that may increase the scope of therapy with rectal EUS are in varying stages of development. Rectal EUS continues to be an important modality for evaluation of benign and malignant disorders of the lower gastrointestinal tract, although its use as a cancer staging modality has declined due to improvements in MRI technology. Various technologies to enhance ultrasound imaging and for therapeutics have been developed that have or may contribute to expanded indications for rectal EUS.

Role of ultrasound in colorectal diseases

Ultrasound is an undervalued non-invasive examination in the diagnosis of colonic diseases. It has been replaced by the considerably more expensive magnetic resonance imaging and computed tomography, despite the fact that, as first examination, it can usefully supplement the diagnostic process. Transabdominal ultrasound can provide quick information about bowel status and help in the choice of adequate further examinations and treatment. Ultrasonography, as a screening imaging modality in asymptomatic patients can identify several colonic diseases such as diverticulosis, inflammatory bowel disease or cancer. In addition, it is widely available, cheap, non-invasive technique without the use of ionizing radiation, therefore it is safe to use in childhood or during pregnancy, and can be repeated at any time. New ultrasound techniques such as elastography, contrast enhanced and Doppler ultrasound, mini-probes rectal and transperineal ultrasonography have broadened the indication. It gives an overview of the methodology of various ultrasound examinations, presents the morphology of normal bowel wall and the typical changes in different colonic diseases. We will pay particular attention to rectal and transperineal ultrasound because of their outstanding significance in the diagnosis of rectal and perineal disorders. This article seeks to overview the diagnostic impact and correct indications of bowel ultrasound.

Predictive factors for recurrence of cryptoglandular fistulae characterized by preoperative three-dimensional endoanal ultrasound

AIM

Precise information regarding the location of an anal fistula and its relationship to adjacent structures is necessary for selecting the best surgical strategy. Retrospective and cross-sectional studies were performed to determine predictive factors for recurrence of anal fistula from preoperative examination by three-dimensional endoanal ultrasound (3D-EAUS).

METHOD

Patients in our tertiary centre and in a private centre specialized in proctology undergoing preoperative 3D-EAUS for cryptoglandular anal fistulae between 2002 and 2012 were included. A questionnaire was sent in September 2013 to assess the patient's condition with regard to recurrence. Variables checked for association with recurrence were gender, type of centre, previous fistula surgery, secondary track formation and classification of the fistula.

RESULTS

There were 143 patients of whom 96 had a low fistula treated by fistulotomy, 28 a high fistula treated by fistulectomy and 19 a high fistula treated by fistulectomy combined with a mucosal advancement flap. The median duration of follow-up was 26 (2-118) months. The fistula recurred in 40 (27%) patients. Independent risk factors included the presence of secondary track formation [hazard ratio 2.4 (95% CI 1.2-51), P = 0.016] and previous fistula surgery [hazard ratio 1.2 (95% CI 1.0-4.6), P = 0.041]. Agreement between the 3D-EAUS examination and the evaluation under anaesthesia regarding the site of the internal opening, classification of the fistula and the presence of secondary tracks was 97%, 98% and 78%.

CONCLUSION

The identification of secondary tracks by preoperative 3D-EAUS examination was the strongest independent risk factor for recurrence. This stresses the importance of preoperative 3D-EAUS in mapping the pathological anatomy of the fistula and a thorough search for secondary track formation during surgery.

Functional Anorectal Disorders

This report defines criteria and reviews the epidemiology, pathophysiology, and management of common anorectal disorders: fecal incontinence (FI), functional anorectal pain and functional defecation disorders. FI is defined as the recurrent uncontrolled passage of fecal material for at least 3 months. The clinical features of FI are useful for guiding diagnostic testing and therapy. Anorectal manometry and imaging are useful for evaluating anal and pelvic floor structure and function. Education, antidiarrheals and biofeedback therapy are the mainstay of management; surgery may be useful in refractory cases. Functional anorectal pain syndromes are defined by clinical features and categorized into three subtypes. In proctalgia fugax, the pain is typically fleeting and lasts for seconds to minutes. In levator ani syndrome (LAS) and unspecified anorectal pain the pain lasts more than 30 minutes, but in LAS there is puborectalis tenderness. Functional defecation disorders are defined by >2 symptoms of chronic constipation or irritable bowel syndrome with constipation, and with >2 features of impaired evacuation i.e., abnormal evacuation pattern on manometry, abnormal balloon expulsion test or impaired rectal evacuation by imaging. It includes two subtypes; dyssynergic defecation and inadequate defecatory propulsion. Pelvic floor biofeedback therapy is effective for treating LAS and defecatory disorders.

Functional Anorectal Disorders

This report defines criteria and reviews the epidemiology, pathophysiology, and management of common anorectal disorders: fecal incontinence (FI), functional anorectal pain and functional defecation disorders. FI is defined as the recurrent uncontrolled passage of fecal material for at least 3 months. The clinical features of FI are useful for guiding diagnostic testing and therapy. Anorectal manometry and imaging are useful for evaluating anal and pelvic floor structure and function. Education, antidiarrheals and biofeedback therapy are the mainstay of management; surgery may be useful in refractory cases. Functional anorectal pain syndromes are defined by clinical features and categorized into three subtypes. In proctalgia fugax, the pain is typically fleeting and lasts for seconds to minutes. In levator ani syndrome (LAS) and unspecified anorectal pain the pain lasts more than 30 minutes, but in LAS there is puborectalis tenderness. Functional defecation disorders are defined by >2 symptoms of chronic constipation or irritable bowel syndrome with constipation, and with >2 features of impaired evacuation i.e., abnormal evacuation pattern on manometry, abnormal balloon expulsion test or impaired rectal evacuation by imaging. It includes two subtypes; dyssynergic defecation and inadequate defecatory propulsion. Pelvic floor biofeedback therapy is effective for treating LAS and defecatory disorders.

Advances in endoscopic ultrasound imaging of colorectal diseases

The development of endoscopic ultrasound (EUS) has had a significant impact for patients with digestive diseases, enabling enhanced diagnostic and therapeutic procedures, with most of the available evidence focusing on upper gastrointestinal (GI) and pancreatico-biliary diseases. For the lower GI tract the main application of EUS has been in staging rectal cancer, as a complementary technique to other cross-sectional imaging methods. EUS can provide highly accurate in-depth assessments of tumour infiltration, performing best in the diagnosis of early rectal tumours. In the light of recent developments other EUS applications for colorectal diseases have been also envisaged and are currently under investigation, including beyond-rectum tumour staging by means of the newly developed forward-viewing radial array echoendoscope. Due to its high resolution, EUS might be also regarded as an ideal method for the evaluation of subepithelial lesions. Their differential diagnosis is possible by imaging the originating wall layer and the associated echostructure, and cytological and histological confirmation can be obtained through EUS-guided fine needle aspiration or trucut biopsy. However, reports on the use of EUS in colorectal subepithelial lesions are currently limited. EUS allows detailed examination of perirectal and perianal complications in Crohn’s disease and, as a safe and less expensive investigation, can be used to monitor therapeutic response of fistulae, which seems to improve outcomes and reduce the need for additional surgery. Furthermore, EUS image enhancement techniques, such as the use of contrast agents or elastography, have recently been evaluated for colorectal indications as well. Possible applications of contrast enhancement include the assessment of tumour angiogenesis in colorectal cancer, the monitoring of disease activity in inflammatory bowel disease based on quantification of bowel wall vascularization, and differentiating between benign and malignant subepithelial tumours. Recent reports suggest that EUS elastography enables highly accurate discrimination of colorectal adenocarcinomas from adenomas, while inflammatory bowel disease phenotypes can be distinguished based on the strain ratio calculation. Among EUS-guided therapies, the drainage of abdominal and pelvic collections has been regarded as a safe and effective procedure to be used as an alternative for the transcutaneous route, while the placing of fiducial markers under EUS guidance for targeted radiotherapy in rectal cancer or the use of contrast microbubbles as drug-delivery vehicles represent experimental therapeutic applications that could greatly impact the forthcoming management of patients with colorectal diseases, pending on further investigations.

Fecal incontinence in the elderly: FAQ

Fecal incontinence (FI) is a common gastrointestinal (GI) complaint in patients aged 65 years and older. This evidence-based review article discusses the epidemiology, pathophysiology, evaluation, and management of FI in the geriatric population. We emphasize aging-related changes leading to and impacting evaluation and treatment of this symptom while incorporating the core geriatric principles of functional status and management aligned with patient preference and goals of care.

Detection of anal sphincter defects in female patients with fecal incontinence: a comparison of 3-dimensional transperineal ultrasound and 2-dimensional endoanal ultrasound

BACKGROUND

Endoanal ultrasound is widely used for the detection of external and internal anal sphincter defects in patients with fecal incontinence. Recently, 3-dimensional transperineal ultrasound has been introduced as a noninvasive imaging method for the detection of these sphincter defects.

OBJECTIVE

This study was designed to assess agreement between 3-dimensional transperineal ultrasound and 2-dimensional endoanal ultrasound regarding the detection of anal sphincter defects in women with fecal incontinence.

DESIGN

This study was designed as a prospective observational study.

SETTINGS

The study took place in a university hospital.

PATIENTS

Between October 2008 and June 2009, all women with concerns of fecal incontinence underwent 2-dimensional endoanal ultrasound as well as 3-dimensional transperineal ultrasound.

MAIN OUTCOME MEASURES

The main outcome measures are the presence of external and internal anal sphincter defects.

RESULTS

Fifty-five patients were included. External and internal anal sphincter defects were observed with 2-dimensional endoanal ultrasound in 27 (49%) and 15 (27%) patients. Three-dimensional transperineal ultrasound detected an external and internal sphincter defect in 19 (35%) and 16 (29%) patients. The Cohen κ coefficient for the detection of external (κ = 0.63) and internal (κ = 0.78) anal sphincter defects was good.

LIMITATIONS

This study's limitations include the absence of a surgical examination as the reference standard in the determination of sphincter defects.

CONCLUSION

This study shows good agreement between 3-dimensional transperineal ultrasound and 2-dimensional endoanal ultrasound regarding the detection of anal sphincter defects. Based on these data, 3-dimensional transperineal ultrasound might be considered as a valuable alternative noninvasive investigation method.

Critical reappraisal of anorectal function tests in patients with faecal incontinence who have failed conservative treatment

OBJECTIVE

Anorectal function tests are often performed in patients with faecal incontinence who have failed conservative treatment. This study was aimed to establish the additive value of performing anorectal function tests in these patients in selecting them for surgery.

PATIENTS AND METHODS

Between 2003 and 2009, all referred patients with faecal incontinence were assessed by a questionnaire, anorectal manometry and anal endosonography. Patients with diarrhea, inflammatory bowel disease, pouches or rectal carcinoma were excluded.

RESULTS

In total, 218 patients were evaluated. Of these, 107 (49%) patients had no sphincter defects, 71 (33%) had small defects and 40 (18%) had large defects. Anorectal manometry could not differentiate between patients with and without sphincter defects. Patients with sphincter defects were only found to have a significantly shorter sphincter length and reduced rectal capacity compared to patients without sphincter defects. Forty-three patients (20%) had a normal anal pressures ≥ 40 mmHg. Seventeen patients (8%) had also a dyssynergic pelvic floor both on clinical examination and anorectal manometry. Fifteen patients (7%) had a reduced rectal capacity between 65 and 100 ml. There was no difference in anal pressures or the presence of sphincter defects in these patients compared to patients with a rectal capacity >150 ml. There was no correlation between anorectal manometry, endosonography and faecal incontinence severity scores.

CONCLUSION

In patients with faecal incontinence who have failed conservative treatment, only anal endosonography can reveal sphincter defects. Anorectal manometry should be reserved for patients eligible for surgery to exclude those with suspected dyssynergic floor or reduced rectal capacity.

The accuracy of a postprocessing technique--volume render mode--in three-dimensional endoanal ultrasonography of anal abscesses and fistulas

OBJECTIVE

This study aimed to evaluate the accuracy of a 3-dimensional volume render mode endoanal ultrasonography in the assessment of anal abscesses and fistulas.

PATIENTS AND METHODS

Three-dimensional endoanal ultrasonography was performed preoperatively in 62 patients with clinical diagnoses of an anal abscess and/or an anal fistula. The accuracy of a volume render mode endoanal ultrasonography was evaluated blindly by 2 observers through a retrospective analysis of all the stored images of anal abscesses and fistulas. Differences in classification of the type of anal abscesses and in determination of the type and location of internal openings of anal fistulas were assessed.

RESULTS

In classification of the primary tract, the agreement between the volume render mode endoanal ultrasonography and surgery was much higher than that for the 3-dimensional endoanal ultrasonography (marginal homogeneity test P > .1, κ = 0.96, and marginal homogeneity test P = .0048, κ = 0.28, respectively). In localizing the internal openings and in classifying anal abscesses, the agreement for both methods with surgery was identical. The interobserver agreement showed complete agreement (100%) with regard to luminance and thickness parameters and very high accuracy for the opacity and filter parameters.

CONCLUSIONS

This study demonstrated that volume render mode endoanal ultrasonography is a useful adjunct method to the 3-dimensional endoanal ultrasonography, showing better classification results of the types of anal fistulas.