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

A Simple Protocol to Effectively Manage Anal Fistulas with No Obvious Internal Opening

Purpose

In some anal fistulas, the internal/primary opening cannot be located even after examination and assessment on MRI or transrectal ultrasound. The efficacy of a simple new protocol to manage such therapeutically challenging fistulas was tested.

Patients and Methods

All anal fistula patients operated consecutively over 7 years were included in the study. A simple two-step protocol was followed for fistulas in which the internal opening was not locatable after clinical examination and MRI assessment. First, the MRI was reassessed. The site where the fistula was closest to the internal sphincter was noted. It was assumed that the internal-opening was located at that position and the fistula was treated accordingly. Second, in horseshoe anal fistulas with no apparent internal opening, it was assumed that the internal opening was located in the midline. Low fistulas were treated by fistulotomy and high fistulas by a sphincter-sparing procedure. Incontinence was evaluated by objective incontinence scores (Vaizey scores).

Results

A total of 757 patients were operated (median follow-up-33 months). Of these, 57 patients were excluded due to short or inadequate follow-up. In 154/700 (22%) patients, the internal opening could not be located while in 546/700 (78%), the internal opening was found. Both the groups were similar in all parameters. In the "internal-opening found" group, the fistula healed completely in 486/546 (89%) and in the 'internal-opening not found group', the fistula healed in 140/156 (90.9%) (p=1.01). The objective continence scores did not change significantly after surgery in both the groups.

Conclusion

This new protocol seems effective as a high cure rate could be achieved in 'internal-opening not found' fistulas which was comparable to fistula healing in the 'internal-opening found' group.

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.

Sonographic appearance of anal cushions of hemorrhoids

AIM

To evaluate the diagnostic value of different sonographic methods in hemorrhoids.

METHODS

Forty-two healthy volunteers and sixty-two patients with grades I-IV hemorrhoids received two different sonographic examinations from January 2013 to January 2016 at the First and Second Hospitals of Xinjiang Medical University in a prospective way. We analyzed the ultrasonographic findings of these participants and evaluated the outcomes. Resected grades III and IV hemorrhoid tissues were pathologically examined. The concordance of ultrasonographic results with pathology results was assessed with the Cohen’s kappa coefficient.

RESULTS

All healthy volunteers and all patients had no particular complications related to sonography. There were no statistically significant differences between the participants regarding age (P = 0.5919), gender (P = 0.4183), and persistent symptoms (P > 0.8692). All healthy control participants had no special findings. However, 30 patients with hemorrhoids showed blood signals around the dentate line on ultrasonography. When grades I and II hemorrhoids were analyzed, there were no significant differences between transrectal ultrasound (TRUS), transperianal ultrasound (TPUS), and transvaginal ultrasound (TVUS) (P > 0.05). Grades III and IV hemorrhoids revealed blood flow with different directions which could be observed as a “mosaic pattern”. In patients with grades III and IV hemorrhoids, the number of patients with “mosaic pattern” as revealed by TRUS, TPUS and TVUS was 22, 12, and 4, respectively. Patients with grades III and IV disease presented with a pathologically abnormal cushion which usually appeared as a “mosaic pattern” in TPUS and an arteriovenous fistula in pathology. Subepithelial vessels of resected grades III and IV hemorrhoid tissues were manifested by obvious structural impairment and retrograde and ruptured changes of internal elastic lamina. Some parts of the Trietz’s muscle showed hypertrophy and distortion. Arteriovenous fistulas and venous dilatation were obvious in the anal cushion of hemorhoidal tissues. After pathological results with arteriovenous fistulas were taken as the standard reference, we evaluated the compatibility between the two methods according to the Cohen’s kappa co-efficiency calculation. The compatibility (Cohein kappa co-efficiency value) between “mosaic pattern” in the TPUS and arteriovenous fistula in pathology was very good (ĸ = 0.8939). When compared between different groups, TRUS presented the advantage that the mosaic pattern could be confirmed in more patients, especially for group A. There was a statistical difference when comparing group A with group B or C (P < 0.05 for both). There were obvious statistical differences between group A and group B with regard to the vessel diameter and blood flow velocity measured by TRUS (P < 0.05).

CONCLUSION

Patients with grades III and IV hemorrhoids present with a pathologically abnormal cushion which usually appears as a “mosaic pattern” in sonography, which is in accord with an arteriovenous fistula in pathology. There are clearly different hemorrhoid structures shown by sonography. “Mosaic pattern” may be a parameter for surgical indication of grades III and IV hemorrhoids.

Transperineal perineal ultrasound versus magnetic resonance imaging in the assessment of perianal Crohn's disease

BACKGROUND

To assess the accuracy of transperineal ultrasound (TPUS), in comparison with magnetic resonance imaging (MRI), in classifying perianal Crohn's disease (CD) according to Parks' classification and the American Gastroenterological Association criteria.

METHODS

Fifty-nine consecutive patients with confirmed or suspected perianal CD underwent TPUS and MRI within 10 days. An independent expert surgical evaluation, which took into account proctological and MRI findings, was used as the gold standard. Fistulae and perianal disease were classified according to Parks' classification and American Gastroenterological Association criteria, respectively.

RESULTS

Forty-six patients showed 64 fistulae (9 intersphincteric, 34 transsphincteric, 2 suprasphincteric, 9 extrasphincteric, and 10 anovaginal) and 23 abscesses were also found. Fifty-one of 54 perianal fistulae (per-lesion sensitivity: 94.4%) and 9 of 10 anovaginal fistulae (sensitivity: 90.0%) were detected and 58 were correctly classified by TPUS (sensitivity: 90.6%; positive predictive value: 93.4%). Overall, TPUS correctly detected and classified the fistulae in 89% of patients and the agreement for classifying perianal fistulae between TPUS and MRI was excellent (K value: 0.783). In contrast, 11 of 23 abscesses were correctly diagnosed by TPUS (sensitivity: 47.8%); although 14 abscesses were diagnosed by TPUS, only 11 were confirmed by MRI (positive predictive value: 78.6%). Overall, TPUS correctly detected and classified fistulae and associated abscesses in 67.3% of patients. Agreement between MRI and TPUS in discriminating simple (15) and complex (29) perianal disease was fairly good (K value: 0.57).

CONCLUSIONS

TPUS is a simple and accurate diagnostic method for classifying perianal fistulae in CD and could be used for the preliminary assessment and follow-up of perianal CD.

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.

Endoanal ultrasound in benign anorectal disorders: clinical relevance and possibilities

Endoanal ultrasound is a well-established technique used to evaluate benign anorectal disorders. The technique is easy to perform, has a short learning curve and causes very little discomfort. Reconstruction of 3D images is possible. The clinical indications for endoanal ultrasound in benign anorectal diseases are fecal incontinence and peri-anal fistula. Sphincter defects can be depicted with precision and correlate perfectly with surgical findings. Furthermore, an impression of sphincter atrophy can be established. With perianal fistula the tracts can be visualized. Introducing hydrogen peroxide via the external fistula opening improves imaging. Endoanal ultrasound and MRI have comparable results in diagnosing anorectal disorders.