Role of bowel ultrasound in the management of postoperative Crohn's disease

Innovative Care for Inflammatory Bowel Disease Patients during the COVID-19 Pandemic: Use of Bedside Intestinal Ultrasound to Optimize Management

Background

The COVID-19 pandemic caused by SARS-CoV-2 has reduced access to endoscopy and imaging. Safe alternatives, available at the bedside, are needed for accurate, non-invasive strategies to evaluate disease activity. The aim of this study is to establish the impact of clinic-based bedside intestinal ultrasound (IUS) on decision making, reduction in reliance on endoscopy and short-term healthcare utilization.

Methods

We conducted a prospective observational evaluation during the COVID-19 pandemic, of the impact of a regional comprehensive care pathway to manage IBD patients consecutively recruited with acute symptoms, or suspected new diagnosis of IBD. Clinic-based access to sigmoidoscopy and bedside intestinal ultrasound were evaluated, used to direct clinical care and avoid hospitalization or hospital-based endoscopy.

Results

A total of 72 patients were seen between March 15 and June 30, 2020. Of these, 57% (41/72) were female, 64% had Crohn's disease (46/72) with 14% (10/72) presenting with symptoms requiring investigation, of which 5 new cases of IBD were identified (50%). Immediate access to ultrasound and sigmoidoscopy led to meaningful changes in management in 80.5% (58/72) of patients. Active inflammation was detected by IUS alone (72.5%, 29/40) or in combination with in-clinic sigmoidoscopy (78%, 18/23) or sigmoidoscopy alone (78% 7/9). Six patients were referred to colorectal surgery for urgent surgical intervention including two patients admitted directly.

Conclusion

Implementation of IUS as part of a clinical care pathway during the COVID-19 pandemic is a useful strategy to enhance care delivery and improve clinical decisions, while sparing other important acute care resources.

Shear Wave and Strain Elastography in Crohn's Disease-A Systematic Review

One modern imaging technique used in the diagnosis of Crohn’s disease (CD) is sonoelastrography of the intestine. Guidelines regarding the use of bowel sonoelastography in CD have still not been specified. The aim of our research was to conduct a systematic review of the use of sonoelastography in the diagnosis, assessment, and monitoring of strictures in the course of CD. A systematic review was conducted according to the PRISMA guidelines statement. The following databases were searched in January 2021: MEDINE via PubMed, Embase and Scopus. The search utilised the following MeSH tags: ‘Ultrasound Shear Wave’, ‘Elastography’, ‘elastogram’, ‘elastographies’ AND ‘Crohn disease’. The inclusion criteria were as follows: from 2010 or later, articles with abstracts, articles in English, human-based studies and original articles. Articles were assessed independently by two reviewers. Out of 181 articles, only 15 met the criteria and were included in the review. Due to a small number of studies and significant methodological differences, the feasibility of using sonoelastography for Crohn’s disease must be proven through further research and analysis. In the future, standardised assessment criteria and cut-off points should be established for both strain elastography (SE) and shear wave elastography (SWE).

Role of Intestinal Ultrasound in the Evaluation of Postsurgical Recurrence in Crohn’s Disease: Correlation with Endoscopic Findings

<b><i>Introduction:</i></b> Endoscopy remains the exam of choice in the evaluation of activity in Crohn’s disease (CD) after surgery (ACD-AS). However, intestinal ultrasound (IUS) may represent a noninvasive alternative. The objective of this study is to determine the diagnostic accuracy of this modality compared to endoscopy. <b><i>Material and Methods:</i></b> This is a cross-sectional study, comprising a period of 14 months, carried out in patients with established CD and ileocecal resection due to the disease. IUS (HI-VISION Avius®, Tokyo, Japan) was performed with linear probe B-mode/Doppler prior to ileocolonoscopy. IUS and ileocolonoscopy were performed on the same day by 2 specialists in Gastroenterology dedicated to ultrasound and inflammatory bowel disease, in a double-blind mode. Collected demographic and clinical data (Harvey-Bradshaw Index [HBI]; remission ≤4), serological/fecal inflammatory parameters (leukocytes [4–10 × 10⁹ cells/L], C-reactive protein [≤0.5 mg/dL], and fecal calprotectin [&#x3c;50 mg/kg]), endoscopy (Rutgeerts score: remission &#x3c;i2), and ultrasound (intestinal wall thickening [≤3 mm] and digestive wall vascularization using the semiquantitative score of Limberg [absent = 0, sparse = 1, moderate = 2, and marked = 3]). <b><i>Results:</i></b> Thirty-nine patients (female: 64.1%, mean age: 43.5 ± 15.3 years) were included. The median post-surgery follow-up was 9 years (IQR 3–12). The Montreal classification was as follows: L1, 61.5% (<i>n</i> = 24); L3, 38.5% (<i>n</i> = 15); B1 and B2, 28.2% (<i>n</i> = 11); and B3, 43.6% (<i>n</i> = 17). Most patients were in clinical remission (87.2%; <i>n</i> = 34), with a mean HBI of 2.1 ± 2.2. Twenty-two patients (56.4%) had normal inflammatory markers. IUS (intestinal wall thickening &#x3e;3 mm and/or Limberg score &#x3e;1) was abnormal in 61.5% (<i>n</i> = 24) of the cases. Endoscopic remission (Rutgeerts score &#x3c;i2) in 53.8% (<i>n</i> = 21) of the cases. Compared to endoscopy, IUS (area under the receiver operating characteristic curve [AUROC] = 0.75, <i>p</i> = 0.007) showed a diagnostic accuracy superior to that of inflammatory parameters (AUROC = 0.66, <i>p</i> = 0.083) and clinical parameters (AUROC = 0.64, <i>p</i> = 0.139). IUS showed a moderate concordance with endoscopy (κ = 0.5, <i>p</i> = 0.001), which was higher than that with inflammatory parameters (ĸ = 0.33, <i>p</i> = 0.041) or clinical parameters (ĸ = 0.29, <i>p</i> = 0.01). <b><i>Conclusions:</i></b> Ultrasound evaluation of the digestive wall is a noninvasive technique that shows a good diagnostic accuracy and a moderate concordance with endoscopy, being superior to clinical and serological/fecal inflammatory parameters.

Usefulness of intestinal ultrasound in inflammatory bowel disease

Imaging techniques play a fundamental role in the initial diagnosis and follow-up of inflammatory bowel disease. Intestinal ultrasound has high sensitivity and specificity in patients with suspected Crohn's disease and in the detection of inflammatory activity. This technique enables the early diagnosis of intra-abdominal complications such as stenosis, fistulas, and abscesses. It has also proven useful in monitoring the response to treatment and in detecting postsurgical recurrence. Technical improvements in ultrasound scanners, technological advances such as ultrasound contrast agents and elastography, and above all increased experience have increased the role of ultrasound in the evaluation of the gastrointestinal tract. The features that make ultrasound especially attractive include its wide availability, its noninvasiveness and lack of ionizing radiation, its low cost, and its good reproducibility, which is important because it is easy to repeat the study and the study is well tolerated during follow-up. This review summarizes the role of intestinal ultrasound in the detection and follow-up of inflammatory bowel disease.

Contrast-enhanced US in Pediatric Patients: Overview of Bowel Applications

Contrast material-enhanced US is a technique that is approved by the U.S. Food and Drug Administration for the characterization of liver lesions and intravesicular applications in children; however, contrast-enhanced US has several other pediatric applications in clinical practice. The most common application is for patients with inflammatory bowel disease (IBD). Contrast-enhanced US can be used to diagnose IBD, distinguish regions of active or chronic inflammation of the bowel wall, and evaluate associated complications such as abscesses, fistulas, and strictures. Dynamic contrast material evaluation provides qualitative and quantitative information about mural and mesenteric blood flow, which is essential in the determination of disease activity in these patients. It also has the potential to provide a means of monitoring the response to therapy beyond endoscopy or MR enterography. In addition to its use for IBD, contrast-enhanced US can be used to assess for bowel perfusion when problem solving in patients with necrotizing enterocolitis, neonatal bowel infarction, or intussusception. It is a useful imaging technique to fortify diagnoses that may otherwise be indeterminate, such as appendicitis, epiploic appendagitis, intraluminal bowel masses, and complex cysts. Finally, innovative applications such as shear-wave elastography have the potential to provide information about the stiffness of the bowel wall. Online supplemental material is available for this article. ©RSNA, 2020 See discussion on this article by Watson and Humphries.

Terminal Ileum Thickness During Maintenance Therapy Is a Predictive Marker of the Outcome of Infliximab Therapy in Crohn Disease

BACKGROUND

Mucosal healing has been associated with long-term response to therapy for Crohn disease (CD). However, little is known about the significance of terminal ileum (TI) transmural thickness in predicting clinical outcomes.

METHODS

In this retrospective observational cohort study, we examined the association of an index ultrasonographic assessment of TI thickness during the maintenance phase and the subsequent clinical outcome of CD in a cohort of patients treated with infliximab (IFX). Treatment failure was defined as treatment discontinuation because of lack of efficacy, a need for dose escalation, or surgery. Clinical response was defined as treatment continuation in the absence of any of the aforementioned failure criteria.

RESULTS

Sixty patients with CD receiving IFX therapy were included in the study. The patients were followed for a median of 16 months (5-24 months) after an index intestinal ultrasound. Thirty-eight patients (63.3%) maintained response to the therapy and 22 patients (36.6%) failed the treatment, with a mean follow up of 10.5 months (6.5-17 months) vs 9.25 months (1-10.25 months), respectively. On univariate analysis, the only variables differing between treatment response and failure were a TI thickness of 2.8 vs 5 mm (P < 0.0001) and an IFX trough level of 6.6 vs 3.9 µg/mL (P = 0.008).On multivariable analysis, only a small bowel thickness of ≥4 mm was associated with the risk of treatment failure (odds ratio, 2.9; 95% CI, 1.49-5.55; P = 0.002).

CONCLUSIONS

Our findings suggest that transmural thickness of ≥4 mm can predict subsequent treatment failure in patients with CD treated using IFX, indicating transmural thickness <4 mm as a potential novel valuable therapeutic target.

Bowel Ultrasound State of the Art: Grayscale and Doppler Ultrasound, Contrast Enhancement, and Elastography in Crohn Disease

Bowel ultrasound (US) is accurate for assessing bowel inflammation and complications in Crohn disease. Additionally, contrast-enhanced US provides a quantitative, objective measurement of inflammatory activity in inflammatory bowel disease, and shear wave elastography predicts the stiffness of bowel, an increase of which suggests less response to medical therapy, often necessitating surgery. Overall, bowel US is an excellent, safe, and repeatable choice for routine surveillance and for urgent imaging. We describe an approach to evaluating inflammatory bowel disease and review its features on standard grayscale US with Doppler imaging and show how contrast-enhanced US and shear wave elastography can distinguish between inflammatory and fibrostenotic bowel.

Optimal delivery of follow-up care after surgery for Crohn's disease: current perspectives

Despite improvements in medical therapies for Crohn’s disease (CD), up to 70% of patients require surgery within 10 years of diagnosis. Surgery is not curative, and almost all patients will experience endoscopic recurrence, and many will go on to clinical recurrence. Identifying patients at high-risk of endoscopic recurrence and standardizing postoperative assessments are essential in preventing clinical recurrence of CD. In this review, we discuss the assessment, monitoring, and treatment of postoperative CD patients. We address the various individual risk factors as well as composite risk factors. Medications used for primary CD treatment can be used in the postoperative setting to prevent endoscopic or clinical recurrence with varying efficacy, although the cost-effectiveness of these approaches are not fully understood. Future directions for postoperative CD management include evaluation of newer biologic agents such as anti-integrin therapy and fecal microbiota transplant for prevention of recurrence. Development of a standard preoperative risk assessment tool to clearly stratify those at high-risk of recurrence is necessary to guide empiric therapy. Lastly, the incorporation of noninvasive testing into disease monitoring will likely lead to early detection of endoscopic recurrence that will allow for tailored treatment to prevent clinical recurrence.

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.