Three-dimensional endoanal ultrasonographic assessment of an anal fistula with and without H2O2 enhancement

Comparative Study of Diluted Hydrogen Peroxide and Sulfur Hexafluoride in the Contrast-Enhanced Ultrasound Assessment of Anal Fistulas

BACKGROUND

Endoanal ultrasound for the diagnosis of anal fistulas requires the injection of hydrogen peroxide, but it is often uncomfortable for the patient and has the potential to cause complications. Novel ultrasound contrast is currently available.

OBJECTIVE

To assess the efficacy and safety of sulfur hexafluoride as an ultrasound contrast agent for the diagnosis of a perianal fistula by comparing it with those of 50% diluted hydrogen peroxide.

DESIGN

Double-blinded superiority study with 4 consecutive visits to perform an ultrasound without contrast, a hydrogen peroxide-enhanced ultrasound, a sulfur hexafluoride-enhanced ultrasound, and a rectal exploration in the operating room (the criterion standard). The 3 expert surgeon sonographers independently reviewed the ultrasound images.

SETTING

This study was conducted at a single university hospital.

PATIENTS

Data from 176 patients were evaluated.

MAIN OUTCOME MEASURES

Demographic and exploratory data and the ultrasound findings related to the location of the internal fistula orifice, description of the primary and secondary tracts, and presence of cavities and sphincter defects were analyzed. Complications occurring before and after the contrast agent administration and pain score measured using a visual analog scale were considered.

RESULTS

Eighty-eight patients were included (men: 71.5%; mean age: 48.3 years), with 62.5% having a complex type fistula and 83.7% having a transsphincteric type fistula. Sulfur hexafluoride-enhanced ultrasounds demonstrated a higher interobserver agreement in determining the secondary tracts (κ = 0.604) and anal fistula height (κ = 0.604) compared with other methods. Both hydrogen peroxide-enhanced ultrasound (90.91%) and sulfur hexafluoride-enhanced ultrasound (89.77%) detected the internal orifice more frequently than ultrasounds without contrast (62.5%; p < 0.001), with no differences between contrast agents ( p = 0.810). Sulfur hexafluoride-enhanced ultrasound was less painful than peroxide-enhanced ultrasound ( p < 0.001).

LIMITATIONS

Most of the patients had transsphincteric anal fistulas.

CONCLUSIONS

Sulfur hexafluoride proved comparable to hydrogen peroxide in evaluating fistulous tracts and identifying the internal orifice, and it significantly reduced pain and discomfort. Furthermore, it demonstrated a higher interobserver agreement in determining the secondary tracts and anal fistula height compared with other methods. See Video Abstract .

ESTUDIO COMPARATIVO DE PERXIDO DE HIDRGENO DILUIDO Y HEXAFLUORURO DE AZUFRE EN LA EVALUACIN ECOGRFICA CON CONTRASTE DE FSTULAS ANALES

ANTECEDENTES:La ecografía endoanal para el diagnóstico de fístulas anales requiere la inyección de peróxido de hidrógeno, pero generalmente resulta incómoda para el paciente y presenta potenciales complicaciones. Actualmente se encuentran disponibles nuevos contrastes ecográficos.OBJETIVO:Evaluar la eficacia y seguridad del hexafluoruro de azufre como agente de contraste ecográfico para el diagnóstico de fístula perianal comparándolo con el peróxido de hidrógeno diluido al 50%.DISEÑO:Estudio de superioridad doble ciego con cuatro visitas consecutivas realizando una ecografía sin contraste, ecografía potenciada con peróxido de hidrógeno, ecografía potenciada con hexafluoruro de azufre y exploración rectal en el quirófano (el estándar de oro). Las imágenes ecográficas fueron revisadas de forma independiente por tres cirujanos ecografistas expertos.AJUSTE:Estudio llevado a cabo en un único hospital universitario.PACIENTES:Se evaluaron datos de 176 pacientes.PRINCIPALES MEDIDAS DE RESULTADO:Se analizaron los datos demográficos y exploratorios y los hallazgos ecográficos relacionados con la ubicación del orificio interno de la fístula, descripción de los trayectos primario y secundario y la presencia de cavidades y defectos del esfínter. Se consideraron las complicaciones ocurridas antes y después de la administración del agente de contraste y la presencia de dolor medido mediante un puntaje.RESULTADOS:Se incluyeron 88 pacientes (hombres: 71,5%; edad media: 48,3 años). El 62,5% fueron tipo complejo y el 83,7% tipo transesfintérico. Las ecografías mejoradas con hexafluoruro de azufre demostraron mayor concordancia interobservador en la determinación de los trayectos secundarios (κ = 0,604) y la altura de la fístula anal (κ = 0,604) en comparación con otros métodos. Tanto la ecografía con peróxido de hidrógeno (90,91%) como la ecografía con hexafluoruro de azufre (89,77%) detectaron con mayor frecuencia el orificio interno que la ecografía sin contraste (62,5%) (p < 0,001), sin diferencias entre agentes de contraste (p = 0,810). La ecografía potenciada con hexafluoruro de azufre fue menos dolorosa que la ecografía potenciada con peróxido (p < 0,001).LIMITACIONES:La mayoría de los pacientes presentaron fístulas anales transesfintéricas.CONCLUSIONES:El hexafluoruro de azufre demostró ser comparable al peróxido de hidrógeno en la evaluación de los trayectos fistulosos y la identificación del orificio interno y con reducción significativa del dolor y malestar. Además, demostró mayor concordancia interobservador en la determinación de los trayectos secundarios y la altura de la fístula anal en comparación con otros métodos. (Traducción-Dr. Fidel Ruiz Healy ).

Postoperative three-dimensional endoanal ultrasound findings and relation to anal fistula plug failure

OBJECTIVES

To explore the utilization of three-dimensional (3D) endoanal ultrasound (EAUS) for the follow-up of the anal fistula plug (AFP), describe morphological findings in postoperative 3D EAUS, and evaluate if postoperative 3D EAUS combined with clinical symptoms can predict AFP failure.

MATERIALS AND METHODS

A retrospective analysis of 3D EAUS examinations performed during a single-centre study of prospectively included consecutive patients treated with the AFP between May 2006 and October 2009. Postoperative assessment by clinical examination and 3D EAUS was performed at 2 weeks, 3 months and 6-12 months ("late control"). Long-term follow-up was carried out in 2017. The 3D EAUS examinations were blinded and analysed by two observers using a protocol with defined relevant findings for different follow-up time points.

RESULTS

A total of 95 patients with a total of 151 AFP procedures were included. Long-term follow-up was completed in 90 (95%) patients. Inflammation at 3 months, gas in fistula and visible fistula at 3 months and at late control, were statistically significant 3D EAUS findings for AFP failure. The combination of gas in fistula and clinical finding of fluid discharge through the external fistula opening 3 months postoperatively was statistically significant (p < 0.001) for AFP failure with 91% sensitivity and 79% specificity. The positive predictive value was 91%, while the negative predictive value was 79%.

CONCLUSIONS

3D EAUS may be utilized for the follow-up of AFP treatment. Postoperative 3D EAUS at 3 months or later, especially if combined with clinical symptoms, can be used to predict long-term AFP failure.ClinicalTrials.gov identifier NCT03961984.

Benign Anorectal Disorder Management in Low-Resource Settings

There are many benign anorectal disorders, which can make patients seek care. In low-resource settings, the incidence of those pathologies is not different from the industrialized and western world. However, an interesting difference colorectal surgeons and gastroenterologists can face is the fact that many patients do not seek help or are not aware and have little opportunities to be helped. Latin America population is estimated to be around 8% of the world population, with Brazil having the largest percentage. Infectious diseases, which were previously under control or were steadily declining, have emerged. For example, we have seen resurgence of dengue, malaria, and syphilis in pregnancy, as well as other sexually transmitted diseases that can affect the anorectal region. In this article, we will address the most common benign anorectal disorders.

Effects of preoperative endoanal ultrasound on functional outcome after anal fistula surgery

Objective

Endoanal ultrasound (EAUS) is a recommended preoperative investigation for fistula-in-ano (FiA) which aims to provide the best chance of healing and preservation of continence function. This study aims are (1) to assess effect of EAUS on functional outcome and (2) to determine factors associated with clinical outcomes after FiA surgery.

Design

Retrospective analysis of subjects with cryptogenic FiA between January 2011 and December 2016, in a tertiary hospital, was performed by comparing EAUS and no-EAUS groups. Postoperative change in St. Mark’s faecal incontinence severity score (cFISS=FISS at 6 months after surgery–FISS before surgery) were compared. General linear model was used to determine factors associated with cFISS. Binary logistic regression was used to assess factors related to clinical outcomes. A p-value of <0.05 is considered significant.

Results

We enrolled 339 subjects; 109 (M:F 91:18, mean age 41.7±13.6 years) of 115 in EAUS group and 230 in no-EAUS group (M:F 195:35, mean age 42.6±13.0 years). There were higher proportions of recurrent cases (24.8% vs 13.9%, p=0.014) and complex FiA (80.7% vs 50.4%, p=0.001) in EAUS group. Postoperative FISS (mean±SE) were increased in both groups; preoperative versus postoperative FISS were 0.36±0.20 versus 0.59±0.25 in EAUS group (p=0.056) and 0.31±0.12 versus 0.76±0.17 in no-EAUS group (p<0.001). EAUS had significant effects on cFISS in both univariate analysis, F(1,261)=4.053, p=0.045; and multivariate analysis, F(3,322)=3.147, p=0.025, Wilk’s Lambda 0.972. Other associated factors included recurrent fistula (F(3,322)=0.777, p=0.007, Wilk’s Lambda 0.993) and fistula classification (F(3,322)=16.978, p<0.001, Wilk’s Lambda 0.863). After a mean follow-up of 33.6±28.6 weeks, success rate was 63.3%(EAUS) and 60% (no-EAUS), p=0.822. Factors associated with clinical outcomes were fistula complexity, number of tracts, recurrence, number of previous surgery and type of operations. Accuracy of EAUS was 90.8% and not related to clinical outcomes (p=0.522).

Conclusion

EAUS had favourable effects on functional outcome after FiA surgery while multiple factors were associated with clinical outcomes. EAUS is useful, accurate, inexpensive and can be the first tool for planning of complex and recurrent FiA.

One stage fistulectomy for high anal fistula with reconstruction of anal sphincter without fecal diversion

Perianal sepsis and fistula is a troublesome disease in the field of colorectal surgery in term of recurrence and fecal incontinence. The aim of our study is to evaluate the role of 'one stage complex anal fistula excision with reconstruction of anal sphincter without stool diversion' regarding fecal incontinence and recurrence. This was prospective cohort study on 175 patients of complex high peri-anal fistulae, the patients were subjected to fistulectomy and reconstruction (primary suture repair) of anal sphincter without stool diversion, the patients were followed up 1 year postoperatively after complete healing of the wound regarding their continence to stool and gases using Wexner score and recurrence of the fistula which is examined clinically and radio-logically using MRI. Among the 175 patients only four had developed fecal incontinence with varying degrees in which 2 patients developed gas incontinence and 2 patients developed soiling, after 3 months 8 patients had recurrence and after 6-9 months 6 patients developed recurrence . Also at the end of follow up period upon performing the confirmatory MRI, 2 patients showed hidden fistulous tracts ending into a high abscess cavity. This ends up into total of 16 recurrent cases. Five patients experienced delayed wound healing. In conclusion, Compared to other treatment modalities for complex anal fistula found in literature, it had been found that one stage surgery (fistulectomy with primary sphincter repair) has good results regarding healing of the fistula with low risk of incontinence, low recurrence rate and good wound healing.

Value of three-dimensional endoanal ultrasound scan (3D-EAUS) in preoperative assessment of fistula-in-ano

Objective

The aim of this study was to determine the accuracy of three-dimensional endoanal ultrasound scan (3D-EAUS) in the pre-operative assessment of fistula-in-ano in identifying the fistula tract and comparing with findings at surgery in a South Asian cohort. A retrospective analysis of 87 patients with suspected fistula-in-ano who underwent pre-operative 3D-EAUS between January 2009 and January 2016 was carried out. All patients subsequently had surgical exploration under anaesthesia (EUA), irrespective of 3D-EAUS findings. The 3D-EAUS results were compared with the surgical findings to determine the accuracy of 3D-EAUS.

Results

A total of 86 (98.9%) patients (male = 75) were subsequently shown to have a fistula at surgical exploration and of them, 3D-EAUS detected a fistula in 79 (92%) patients. In this cohort, 3D-EAUS correctly predicted the surgical findings in (n = 61, 70.9%) patients with the highest accuracy being for transphincteric fistulae (87.1%). However, the overall concordance in our study was low with a kappa coefficient of 0.318. Additional findings such as sphincter defects were detected by the 3D-EAUS in 37 patients (internal sphincter defects-21, external sphincter defects-7, both-9) which were not evident at EUA. Therefore, 3D-EAUS had a good accuracy in selected types of fistulae and particularly useful in identifying sphincter defects before surgery.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4098-2) contains supplementary material, which is available to authorized users.

The treatment of anal fistula: second ACPGBI Position Statement - 2018

It is over 10 years since the first ACPGBI Position Statement on the management of anal fistula was published in 2007. This second edition is the result of scrutiny of the literature published during this time; it updates the original Position Statement and reviews the published evidence surrounding treatments for anal fistula that have been developed since the original publication.

Utility of Endoanal Ultrasonography in Assessment of Primary and Recurrent Anal Fistulas and for Detection of Associated Anal Sphincter Defects

BACKGROUND

Tridimensional endoanal ultrasonography (3D-EAUS) has been used for the assessment of various anorectal lesions. Previous studies have reported good accuracy of 3D-EAUS in preoperative assessment of fistula-in-ano (FIA). This study aimed to assess the diagnostic utility of 3D-EAUS in preoperative evaluation of primary and recurrent FIA and its role in detection of associated anal sphincter (AS) defects.

PATIENTS AND METHODS

Prospectively collected data of patients with FIA who were investigated with 3D-EAUS were reviewed. The findings of EAUS were compared with the intraoperative findings, the reference standard, to find the degree of agreement regarding the position of the internal opening (IO) and primary tract (PT), and presence of secondary tracts using kappa (k) coefficient test. A subgroup analysis was performed to compare the accuracy and sensitivity of EAUS for primary and recurrent FIA.

RESULTS

Of the patients, 131 were included to the study. EAUS had an overall accuracy of 87, 88.5, and 89.5% in detection of IO, PT, and AS defects, respectively. There was very good concordance between the findings of EAUS and intraoperative findings for the investigated parameters (kappa = 0.748, 0.83, 0.935), respectively. Accuracy and sensitivity of EAUS in recurrent FIA were insignificantly lower than primary cases. EAUS detected occult AS defects in 5.3% of the patients studied.

CONCLUSION

The diagnostic utility of 3D-EAUS was comparable in primary and recurrent FIA. 3D-EAUS was able to detect symptomatic and occult AS defects with higher accuracy than clinical examination.

New horizons in the imaging of perianal Crohn's disease: transperineal ultrasonography

perianal disease, most commonly manifest as fistula or abscess formation, affects up to 40% of patients with crohn's disease. perianal crohn's disease is disabling, associated with poor outcomes, and represents a therapeutic challenge for physicians. correct diagnosis and classification of perianal disease is the first crucial step for appropriate multidisciplinary management. Areas covered: A literature search was performed of the PubMed database using the terms 'transperineal ultrasonography', 'transperineal ultrasound', 'perianal disease', 'perianal fistula', 'perianal abscess', 'magnetic resonance', 'endoanal ultrasonography', 'endoscopic ultrasound' in combination with 'Crohn's disease'. A comprehensive review of the relative advantages and disadvantages of the various methods of evaluation of perianal Crohn's disease is provided. A particular focus is placed on transperineal ultrasonography, including historical and technical factors, advantages and limitations, and its current role in practice. An algorithm for integration of transperineal ultrasound into the management of perianal Crohn's disease into clinical practice is proposed, along with future areas research. Expert commentary: Transperineal ultrasound is a simple, safe, cheap and reliable imaging technique for evaluation of perianal Crohn's disease, which should be used more frequently in clinical practice.

Three-dimensional endoanal ultrasound is accurate and reproducible in determining type and height of anal fistulas

AIM

Surgical treatment of high anal fistulas is associated with the potential risk of faecal incontinence and recurrence. The primary aim of this study was to determine the accuracy of three-dimensional endoanal ultrasound (3D-EAUS) in the assessment of height and type of anal fistulas, compared to the intra-operative findings (gold standard). The secondary aim was to evaluate the inter-observer reproducibility of 3D-EAUS.

METHOD

The study design was a prospective analysis of retrospective data. 299 patients (202 men), mean age 45.3 years, who underwent surgery for anal fistulas, were included. All patients were preoperatively assessed by 3D-EAUS. Two readers independently reviewed the volumes to determine the type and height of fistulas. Sensitivity, specificity, positive and negative predictive values, proportion of agreements and Cohen's kappa coefficient (κ) were calculated for both examiners. Ultrasound findings were compared with intra-operative data (reference standard), evaluated blindly by the surgeons.

RESULTS

At surgery, 201 (67%) were transsphincteric, 49 (16%) suprasphincteric, 47 (16%) intersphincteric and two (1%) extrasphincteric fistulas. Intra-operatively, 177 (59%) were low and 122 (41%) high fistulas. The overall accuracy of 3D-EAUS was 91% for fistula type (271/299 fistulas: 97% transsphincteric, 100% intersphincteric, 57% suprasphincteric, 0% extrasphincteric) and 92% for fistula height (275/299 fistulas: 80% high and 100% low). Both readers reported very good agreement with surgery in the assessment of fistula type (proportion of agreement 0.88, κ = 0.89) and height (proportion of agreement 0.90, κ = 0.91).

CONCLUSIONS

3D-EAUS is an accurate and reproducible modality for the assessment of type and height of anal fistulas.

Endoanal ultrasound in perianal fistulae and abscesses

Endoanal ultrasound is a technique that provides imaging of the anal sphincters and its surrounding structures as well as the pelvic floor. However, endoanal magnetic resonance imaging (MRI) is preferred by most physicians, although costs are higher and demand easily outgrows availability. Endoanal ultrasound is an accurate imaging modality delineating anatomy of both cryptoglandular as well as Crohn perianal fistula and abscess. Endoanal ultrasound is comparable with examination under anesthesia and equally sensitive as endoanal MRI in fistula detection. When fistula tracts or abscesses are located above the puborectal muscle, an additional endoanal MRI should be performed. Preoperative imaging is advocated in recurrent cryptoglandular fistula because a more complex pattern can be expected. Endoanal ultrasound can help avoid missing tracts during surgery, lowering the chance for the fistula to persist or recur. It can easily be performed in an outpatient setting and endosonographic skills are quickly incremented. Costs are low and endoanal ultrasound has the potential to improve outcome of patients with both cryptoglandular and fistulizing Crohn disease; therefore, it values more attention.

Role of tridimensional endoanal ultrasound (3D-EAUS) in the preoperative assessment of perianal sepsis

PURPOSE

The aim of this study was to evaluate the accuracy of tridimensional endoanal ultrasound (3D-EAUS) in the diagnosis of perianal sepsis comparing the results with the surgical findings, considered as reference standard.

METHODS

From January 2009 to January 2013, all the patients referred for the assessment and treatment of perianal sepsis with suspected anorectal origin were enrolled in the study. All patients gave informed written consent. Prior to surgery, all the patients underwent anamnestic evaluation, clinical examination, and unenhanced and H2O2-enhanced 3D-EAUS. Surgery was performed by a colorectal surgeon blinded to the 3D-EAUS results.

RESULTS

A total of 212 patients with suspected perianal suppurations were assessed during the study period. In 12 patients, the H2O2-enhanced 3D-EAUS was not performed, and so, they were excluded from the study. Very good agreement between 3D-EAUS and examination under anesthesia (EUA) in the classification of primary fistula tracts (kappa = 0.93) and in the identification of fistula internal opening (kappa = 0.97) was found. There was a good concordance (kappa = 0.71) between 3D-EAUS and surgery in the detection of fistula secondary extensions. The overall sensitivity and specificity of 3D-EAUS in the diagnosis of perianal sepsis were 98.3 and 91.3% respectively.

CONCLUSION

3D-EAUS is a safe and reliable technique in the assessment of perianal sepsis. It may assist the surgeon in delineating the fistula tract anatomy and in determining the origin of sepsis, supporting the preoperative planning of definitive and appropriate surgical therapy.

Peroxide-enhanced 3-dimensional endovaginal ultrasound imaging for diagnosis of rectovaginal fistula

We present a case of a rectovaginal fistula identified with peroxide-enhanced 3-dimensional endovaginal ultrasonography.

CASE

A 36-year-old woman with history of ulcerative colitis, status post-ileoanal J-pouch anastomosis, and total proctocolectomy presented with leakage of stool from her vagina. The fistula tract could not be fully visualized directly or identified on endoanal ultrasonography, but was diagnosed by peroxide-enhanced endovaginal ultrasound.The use of peroxide-enhancement while performing 3-dimensional endovaginal sonographic imaging may be of benefit to patients with rectovaginal fistulas that cannot be fully evaluated by physical examination or more typical use of endoanal ultrasonography.

Transperineal ultrasonography in perianal Crohn's disease and recurrent cryptogenic fistula-in-ano

AIM

Successful anal fistula care is aided by specialized imaging accurately defining the site of the internal opening and fistula type. Imaging techniques are complementary, designed to answer specific anatomical questions. There are limited data concerning the clinical value of transperineal ultrasound (TP-US) in both cryptogenic fistula-in-ano and perianal Crohn's disease (PACD). The aim of the study was to assess the accuracy of TP-US compared with operative findings in patients with perirectal sepsis.

METHOD

Patients with recurrent cryptogenic anal fistula and PACD referred for sonography were examined using TP-US by a single examiner blinded to the operative results. Fistulae were categorized by the Parks classification predicting the site of the internal fistula opening. Ancillary horseshoe collections, abscesses and secondary tracks were defined.

RESULTS

Fourteen patients with PACD and 27 patients with recurrent cryptogenic fistula-in-ano were analysed with comparative images and operative data. Correlation of fistula type for cryptogenic and PACD patients respectively was 23/27 (85.2%) and 12/14 (85.7%), with a correlative internal opening site (when found at surgery) of 16/22 (72.3%) and 12/14 (85.7%). Misclassification of fistula type in cryptogenic cases occurred in the presence of ancillary abscesses with associated acoustic shadowing. In PACD patients, TP-US was used when anal stenosis precluded endoanal ultrasonography, assisting in the diagnosis of recto-vaginal fistulae.

CONCLUSION

TP-US is a useful complementary technique to assess fistula-in-ano and has special advantage when there is anal canal distortion, complex fistula type or suspicion of a recto-vaginal fistula.

Are there specific endosonographic features in Crohn's patients with perianal fistulae?

Both 2-dimensional and 3-dimensional endoanal ultrasounds have been shown to be accurate in the definition of the anatomy of complex fistulae-in-ano in patients with perianal Crohn's disease. Recently, a Crohn's Ultrasound Fistula Sign (CUFS) has been suggested as a discriminating feature of perianal Crohn's disease as has the presence of fistulous debris and fistular bifurcation. We blindly assessed 197 patients (39 Crohn's fistulae and 158 cryptogenic fistulae) to determine if these signs differentiated fistula types. The incidence of CUFS in Crohn's cases was 17/39 (43.6%) and in cryptogenic cases was 4/158 (2.5%) (P<0.0001). The sensitivity, specificity, positive and negative predictive values and accuracy for CUFS were 43.6%, 97.5%, 80.9%, 87.5% and 86.8%, respectively. The presence of debris and fistula bifurcation in evaluable cases had a high specificity (87.2% and 81.8%, respectively) but poor sensitivity. The kappa values for or against CUFS, debris and bifurcation in Crohn's cases between 2 observers blinded to the diagnosis were 0.85, 0.72 and 0.93, respectively and in cryptogenic fistulae were 0.89, 0.85 and 0.80, respectively. The kappa values of an agreed consensus for CUFS in Crohn's disease, cryptogenic fistulae and overall with a third observer with no ultrasound experience were 0.62, 0.85 and 0.77, respectively. The presence of CUFS differentiates Crohn's-related from cryptogenic fistulae-in-ano with a high level of agreement for this sign between experienced and inexperienced observers blinded to the underlying diagnosis.

Transperineal ultrasonography as a complementary diagnostic tool in identifying acute perianal sepsis

BACKGROUND

Successful anal fistula care in complex cases can be assisted by specialized imaging which accurately defines the site of the internal fistula opening and the fistula type. There are currently limited data concerning the clinical indications for and accuracy of transperineal ultrasound (TP-US) in acute perianal sepsis. The aims of this study were to compare the anatomical interpretation of TP-US images with magnetic resonance imaging (MRI) and surgical findings in an unselected patient cohort presenting with acute perianal sepsis.

METHODS

Sixty-seven consecutive patients with acute anorectal sepsis referred from the surgical department were examined using TP-US and Gadolinium-enhanced MRI with both examiners blinded to the surgical results. Fistulae were categorized by the Parks' classification of fistula type.

RESULTS

Thirty-six abscesses were detected by MRI, 38 by TP-US and 30 by surgical examination. Operatively discordant cases showed only ischiorectal panniculitis. TP-US was more accurate in the diagnosis of superficial sepsis and MRI in the diagnosis of deep-seated perirectal infection. TP-US and MRI show concordance with operative findings in fistula diagnosis with a tendency for TP-US to overdiagnose trans-sphincteric fistulae and MRI to over diagnose extra-sphincteric fistulae. Comparison of TP-US with MRI showed good agreement for perianal abscess diagnosis (τ = 0.82) and for fistula diagnosis (τ = 0.68). For fistulae, TP-US showed moderate agreement with surgery (τ = 0.43) with only fair agreement between MRI and surgery (τ = 0.29).

CONCLUSIONS

Transperineal ultrasound complements other imaging modalities in the anatomical diagnosis of acute perianal abscesses and fistulae. It has specific advantages over other techniques and is accurate in the detection of superficially located perirectal sepsis showing concordance with MRI and surgical findings.

[Anorectal diagnostics for proctological diseases]

The majority of proctological diseases can be defined by a structured evaluation of the symptoms and a physical examination. Magnetic resonance imaging (MRI) and anal endosonography can detect complex anal fistulas with a high accuracy but MRI should be preferred because of its objective visualization. Functional anorectal disorders are multifactorial and show morphological and functional irregularities in different compartments of the pelvic floor which is why MR defecography is now one of the most important methods in diagnostic algorithms. Interpreting the results of anal endosonography, anal manometry and neurophysiological testing is highly demanding because of large interindividual variability. Scores are used for objective measurement of symptom severity and quality of life. In clinical practice, well validated scores evaluated in large patient groups with predetermined circumstances are needed. Bringing together morphological results with scores based on subjective perception is required to optimize diagnostics and therapy evaluation in proctology.

3D intrastomal ultrasonography, an instrument for detecting stoma-related fistula

BACKGROUND

The aim of the present study was to evaluate the recently developed 3D intrastomal ultrasonography in diagnosing stoma-associated complaints and suspected complications after parastomal hernia repair such as peristomal fistula and abscesses.

METHODS

3D intrastomal ultrasonography was used to image peristomal tissue in two patients with complaints after parastomal hernia repair performed with IPOM (intraperitoneal onlay mesh). One patient had ulcerative colitis and one Crohn's disease. Both patients were investigated because of pain and in one case also signs of a subcutaneous abscess.

RESULTS

Intrastomal ultrasonography revealed fistulas connected to the intestinal segment leading to the stoma in both cases. Both cases also showed signs of a fistula descending to the abdominal cavity. In one case, a subcutaneous abscess was identified and in the other a small abscess adjacent to the fistula and the edge of the fascia.

CONCLUSIONS

Stoma complaints after surgery for parastomal hernia with implantation of IPOM mesh can be diagnosed using 3D intrastomal ultrasonography. This new 3D technique for imaging intrastomal hernia can be used to complement traditional methods in the detection of stoma-associated abscesses and fistulas with or without foreign material such as mesh.

Update on anal fistulae: surgical perspectives for the gastroenterologist

Anal fistulae are common and debilitating; they are characterized by severe pain and discharge. They arise following infection near the anal canal, or as a primary event from an abscess in the abdomen, fistulating into the vagina or perianal skin. The term 'cryptoglandular' is given to abscesses arising from the anal glands.For many years, the treatment of choice was to lay open the fistula; however, this risks causing incontinence with potentially devastating consequences. Alternative surgical treatments include setons, fibrin glue, collagen plugs and flaps to cover the internal fistula opening. These have achieved varying degrees of success, as will be discussed. The present review also discusses anal fistulae in light of much recently published literature. Currently, anal fistulae remain challenging and require specialist expertise; however, new treatment options are on the horizon.

Endoanorectal ultrasonography

Endoanorectal ultrasonography (EARUS) may be used for diagnosing various anorectal disorders. EARUS is easy to perform, has a short learning curve, and causes less discomfort than routine digital examination. Anal sphincters can be clearly visualized, and one can easily distinguish between the internal (hypoechoic) and external (hyperechoic) anal sphincters. Other pelvic floor structures, like the puborectalis muscle, can also be visualized. The use of contrast agents can increase the accuracy of EARUS in the assessment of perianal fistulae. In addition, EARUS is an excellent alternative to expensive magnetic resonance imaging. Besides its use in incontinence and perianal sepsis, the presence of slight or massive submucosal invasion in early rectal cancer may be imaged in greater detail. With 3-dimensional EARUS, it is possible to diagnose the anorectal diseases, in multiplane, with high spatial resolution, adding important information about the therapeutic decision. The normal sonographic anatomy of the anorectum, sonographic findings of anorectal diseases, and indications and limitations of endosonography with complementary techniques such as transvaginal and transperineal ultrasound are reviewed in this article.

Anal fistula: Intraoperative difficulties and unexpected findings

Anal fistula surgery is a commonly performed procedure. The diverse anatomy of anal fistulae and their proximity to anal sphincters make accurate preoperative diagnosis essential to avoid recurrence and fecal incontinence. Despite the fact that proper preoperative diagnosis can be reached in the majority of patients by simple clinical examination, endoanal ultrasound or magnetic resonance imaging, on many occasions, unexpected findings can be encountered during surgery that can make the operation difficult and correct decision-making crucial. In this article we discuss the difficulties and unexpected findings that can be encountered during anal fistula surgery and how to overcome them.

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.