Computer-assisted evaluation of perianal fistula activity by means of anal ultrasound in patients with Crohn's disease

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.

What is the optimal surgical strategy for complex perianal fistulous disease in pediatric Crohn's disease? A systematic review

PURPOSE

Perianal fistulous disease is present in 10-15% of children with Crohn's disease (CD) and is frequently complex and refractory to treatment, with one-third of patients having recurrent lesions. We conducted a systematic review of the literature to examine the best surgical strategy or strategies for pediatric complex perianal fistulous disease (CPFD) in CD.

METHODS

We searched CENTRAL, MEDLINE, EMBASE, and CINAHL for studies discussing at least one surgical strategy for the treatment of pediatric CPFD in CD. Reference lists of included studies were hand-searched. Two researchers screened all studies for inclusion, quality assessed each relevant study, and extracted data.

RESULTS

One non-randomized prospective and two retrospective studies met our inclusion criteria. Combined use of setons and infliximab therapy shows promise as a first-line treatment. A specific form of fistulectomy, "cone-like resection," also shows promise when combined with biologics. Endoscopic ultrasound to guide medical and surgical management is feasible in the pediatric population, though it is unclear if it improves outcomes.

CONCLUSION

There is a paucity of evidence regarding the treatment of CPFD in the pediatric population, and further research is required before recommendations can be made as to what, if any, surgical management is optimal.

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.

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.

Imaging techniques and combined medical and surgical treatment of perianal Crohn's disease

Crohn's disease is a chronic inflammatory disease which may involve any segment of the gastrointestinal tract, most frequently the terminal ileum, the large intestine, and the perianal region. The symptoms of perianal Crohn's disease include skin disorders, hemorrhoids, anal ulcers, anorectal stenosis, perianal abscesses and fistulas, rectovaginal fistulas and carcinoma of the perianal region. The perianal manifestations of Crohn's disease cause great discomfort to the patient and are among the most difficult aspects to treat. Management of perianal disease requires a combination of different imaging modalities and a close cooperation between gastroenterologists and dedicated surgeons.

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.

Incidence and clinical outcomes of intersphincteric abscesses diagnosed by anal ultrasonography in patients with crohn's disease

BACKGROUND

Intersphincteric abscesses have been reported as uncommon manifestations of perianal Crohn's disease (CD) in surgical series, and may be diagnosed earlier by means of anal ultrasonography. The aim of this study was to evaluate the incidence and outcomes of intersphincteric abscess in a prospective cohort of patients with CD referred for perianal symptoms.

METHODS

Of the 420 patients with CD attending our outpatient clinic over a period of 5 years, 55 (31 males, mean age 38 ± 13 years) underwent anal ultrasonography because of newly developed symptoms suggesting perianal disease; a clinical evaluation and perianal examination was performed on the same day.

RESULTS

An intersphincteric abscess was diagnosed in 23 (42%) of the 55 patients with perianal symptoms, for a total cumulative 5-year incidence of 5% (95% confidence interval [CI]: 3%-7%). During a median follow-up period of 23 months (range 6-53), four of these patients required surgery, four developed a perianal fistula or small ischiorectal abscess not requiring surgery, and 15 experienced a benign course. The patients with a benign course had a longer duration of CD at the time of onset of the perianal symptoms.

CONCLUSIONS

Intersphincteric abscesses frequently cause perianal symptoms in patients with CD, and their clinical outcomes vary from rapidly progressive inflammation to a benign self-limiting course. The favorable outcome observed in some patients supports a first-line conservative approach to the condition.

Endoanal ultrasonography may distinguish Crohn's anal fistulae from cryptoglandular fistulae in patients with Crohn's disease: a cross-sectional study

BACKGROUND

The aim of the study was a cross-sectional investigation into the types of anal fistulae in patients with Crohn's disease using 3-dimensional endoanal ultrasonography.

METHODS

The study population consisted of 45 patients with established Crohn's disease referred in a 2-year period for treatment of anal fistula. The fistulae were classified according to the presence of three criteria: 1. bifurcation or secondary extension; 2. cross-sectional width ≥ 3 mm; and 3. content of hyperechoic secretions.

RESULTS

The fistulae of 24 patients (53%) satisfied two or three criteria and were classified as true Crohn's fistulae, while the fistulae of 21 patients satisfied one or none of the criteria and were the cryptoglandular type. The fistulae in the two or three criteria group had been in existence for 8.4 years on average and those in the cryptoglandular group for 4.5 years on average (P = 0.283). The corresponding numbers of previous operations for fistula were 5.7 (range 0-32) and 1.5 (range 0-6), respectively (P = 0.0211). The presence of colitis or proctitis was similar across the groups, but the perianal Crohn's disease activity index was higher with a Crohn's type of fistula (P = 0.0097). Also, a larger proportion had been treated with anti-TNF-monoclonal antibody (0.0169).

CONCLUSIONS

Endoanal ultrasonography was capable of discerning two subgroups of fistula in Crohn's patients. These groups were clinically different indicating that the prospect of surgical cure is also different.

Comparison of high-resolution ultrasound and MR-enterography in patients with inflammatory bowel disease

AIM: To compare the results of high-resolution ultrasound (HR-US) and magnetic resonance enterography (MRE) examinations in patients with inflammatory bowel disease (IBD).

METHODS: The reports of 250 consecutive cases with known IBD, who had an MRE and HR-US examination, were retrospectively analyzed. Using a patient-based approach we evaluated morphological disease features such as affected bowel wall, stenosis, abscess and fistula. The comparison between the two modalities was based on the hypothesis, that any pathological change described in any imaging modality was a true finding, as no further standard of reference was available for complete assessment.

RESULTS: Two hundred and fifty examinations representing 207 different patients were evaluated. Both modalities assessed similar bowel wall changes in 65% of the examinations, with more US findings in 11% and more MRE findings in 15%. When the reports were analyzed with regard to “bowel wall inflammation”, US reported more findings in 2%, while MRE reported more findings in 53%. Stenoses were assessed to be identical in 8%, while US found more in 3% and MRE in 29% (P < 0.01). For abscess detection, US showed more findings in 2% (n = 4) while MRE detected more in 6% (n = 16). US detected more fistulas in 1% (n = 2), while MRE detected more in 13% (n = 32) (P < 0.001). The most common reason for no detected pathology by US was a difficult to assess anatomical region (lesser pelvis, n = 72).

CONCLUSION: US can miss clinically relevant pathological changes in patients with IBD mostly due to difficulty in assessing certain anatomical regions.

Imaging analysis of the gliadin direct effect on tight junctions in an in vitro three-dimensional Lovo cell line culture system

Tight junctions play a pivotal role in maintaining the integrity of the intestinal barrier. Their alteration is involved in the pathogenesis of celiac disease. Our aim was to investigate the gliadin effect on the tight junction proteins in an in vitro three-dimensional cell culture model through imaging analyses. Lovo multicellular spheroids were treated with enzymatically digested (PT) gliadin 500 μg/mL and its effect on actin, occludin and zonula occludens-1, was evaluated by means of confocal laser microscopy, transmission electron microscopy and image capture analysis. Compared to untreated spheroids, PT-gliadin-treated ones showed enlargement of the paracellular spaces (9.0±6.9 vs. 6.2±1.7 nm, p<0.05) at transmission electron microscopy and tight junction protein alterations at confocal microscopy and image analyses. In untreated cell cultures thickness of the fluorescence contour of actin, zonula occludens-1 and occludin appeared significantly larger and more intense than in the treated ones. In occludin planimetric analysis the lengths of the integral uninterrupted cellular contour appeared longer in untreated than in PT-gliadin treated spheroids (71.8±42.8 vs. 23.4±25.9 μm, p<0.01). Our data demonstrated that tight junction proteins are directly damaged by gliadin as shown by means of quantitative imaging analysis.

Endoscopic ultrasound to guide the combined medical and surgical management of pediatric perianal Crohn's disease

BACKGROUND

Perianal fistulas are a debilitating manifestation of Crohn's disease (CD) in the pediatric population and present a management challenge. The aims of this study were to describe our experience using endoscopic ultrasound (EUS) to guide management of perianal CD (PCD) in a pediatric population, and determine whether using EUS to monitor healing after seton placement improves outcomes.

METHODS

We conducted a retrospective study of 2 cohorts: pediatric subjects with PCD who underwent EUS and pediatric subjects who underwent seton placement between 2002 and 2007.

RESULTS

In all, 25 children underwent a total of 42 EUS procedures. Of 28 EUSs performed to evaluate suspected perianal disease, complex fistulizing disease was identified in 15 (54%). Setons were placed after most EUSs demonstrating complex fistulizing disease and after none demonstrating superficial or no fistulizing disease. Of 14 EUSs performed to monitor healing around a seton, 7 (50%) demonstrated persistent peri-seton inflammation. Setons were more often left in place after an EUS revealing persistent inflammation (86% versus 0%), and the patients were more likely to have a biologic initiated or changed (57% versus 0%). Among all subjects who underwent seton placement, time from seton removal to recurrence was longer for those followed by EUS compared to those followed by physical exam only; however, we were not powered to test for statistical significance.

CONCLUSIONS

EUS to guide the combined medical and surgical management of PCD is feasible in the pediatric population. Larger prospective studies are needed to determine if EUS-directed management improves outcomes in pediatric patients with PCD.

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.

Assessing the activity of perianal Crohn's disease: comparison of clinical indices and computer-assisted anal ultrasound

BACKGROUND

Assessing perianal disease activity is important for the treatment and prognosis of Crohn's disease (CD) patients, but the diagnostic accuracy of the activity indices has not yet been established. The aim of this study was to determine the accuracy and agreement of the Fistula Drainage Assessment (FDA), Perianal Disease Activity Index (PDAI), and computer-assisted anal ultrasound imaging (AUS).

METHODS

Sixty-two consecutive patients with CD and perianal fistulae underwent clinical, FDA, PDAI, and AUS evaluation. Perianal disease was considered active in the presence of visible fistula drainage and/or signs of local inflammation (induration and pain at digital compression) upon clinical examination. The AUS images were analyzed by calculating the mean gray-scale tone of the lesion. The PDAI and gray-scale tone values discriminating active and inactive perianal disease were defined using receiver operating characteristics statistics.

RESULTS

Perianal disease was active in 46 patients. The accuracy of the FDA was 87% (confidence interval [CI]: 76%-94%). A PDAI of >4 and a mean gray-scale tone value of 117 maximized sensitivity and specificity; their diagnostic accuracy was, respectively, 87% (CI: 76%-94%) and 81% (CI: 69%-90%). The agreement of the 3 evaluations was fair to moderate. The addition of AUS to the PDAI or FDA increased their diagnostic accuracy to respectively 95% and 98%.

CONCLUSIONS

The diagnostic accuracy of the FDA, PDAI, and computer-assisted AUS imaging was good in assessing perianal disease activity in patients with CD. The agreement between the techniques was fair to moderate. Overall accuracy can be increased by combining the FDA or PDAI with AUS.

Pyogenic complications of Crohn's disease, evaluation, and management

The principal by which treatment of pyogenic complications anorectal disease is guided should rely heavily on small procedure with medical management of rectal disease and limitation of proctectomy. Management of pyogenic complications of abdominal Crohn's by an elective approach after percutanea drainage of abscess and nutritional repletion should prevent long term complication even when its patient is receiving immune suppressive therapy.

A randomized prospective trial of endoscopic ultrasound to guide combination medical and surgical treatment for Crohn's perianal fistulas

AIMS

To prospectively determine if rectal endoscopic ultrasound (EUS) can guide combination medical and surgical therapy and improve outcomes for patients with perianal fistulizing Crohn's disease.

METHODS

Ten patients with perianal Crohn's disease were prospectively enrolled in a randomized prospective pilot study. The patients were randomized to either the EUS cohort or the control group. All patients underwent a rectal EUS to delineate fistula anatomy followed by an examination under anesthesia by a colorectal surgeon with seton placement and/or incision and drainage, as indicated. The surgeon was blinded to the initial EUS results of patients in the control group. Medical treatment was maximized with 6-mercaptopurine (1.0-1.5 mg/kg) or azathioprine (2.0-2.5 mg/kg), ciprofloxacin (1,000 mg a day) or metronidazole (1,500 mg a day), and infliximab (5 mg/kg at 0, 2, and 6 wk and then every 8 wk). For patients in the control group, additional interventions (seton removal and repeat surgery) were at the discretion of the surgeon (without EUS guidance). Patients in the EUS cohort had EUS performed at weeks 22 and 38, with additional surgical interventions based on EUS findings. The primary end point was complete cessation of drainage at week 54. All patients had a repeat EUS performed at week 54 to determine the fistula status on EUS (secondary end point). The need for additional surgery was defined as a treatment failure.

RESULTS

Ten patients were enrolled in the study. One of 5 (20%) in the control group and 4 of 5 (80%) in the EUS group had complete cessation of drainage. From the control group, 3 patients failed due to repeat surgery (2 for persistent/recurrent fistula and 1 for abscess), and 1 had a persistent drainage at week 54. In the EUS cohort, 1 patient had a recurrent abscess after his seton fell out prematurely. In the EUS cohort, the median time to cessation of drainage was 99 days, and the time to EUS evidence of fistula inactivity was 229 days.

CONCLUSION

This pilot study suggests that using EUS to guide combination medical and surgical therapy for perianal fistulizing Crohn's disease improves the outcomes.

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 patient with persistent perianal fistulae

The management of patients with persistent perianal fistulae depends on thorough evaluation by clinical history and examination, assessment of intestinal disease and assessment of perianal disease. The main therapeutic options are medical and surgical treatment and their appropriate integration is essential for the optimal management of the patients. Medical treatment includes antibiotics, azathioprine or 6-mercaptopurine, infliximab and tacrolimus or cyclosporine. Surgical treatment includes fistulotomy, placement of setons, endorectal advancement flaps, fecal diversion and proctectomy. Fistula recurrence often occurs, possibly due to early discontinuation of medication or premature removal of setons. Using anorectal endoscopic ultrasound or magnetic resonance imaging to guide therapy, the healing rates of perianal fistula can be increased. In persistent complex perianal fistulae where medical treatment initially fails, examination under anaesthesia and placement of non-cutting setons, when necessary, combined with medical treatment results in higher healing rates.