Bowel sonography for the diagnosis and grading of postsurgical recurrence of Crohn's disease

Outcomes and Endpoints of Postoperative Recurrence in Crohn's Disease: Systematic Review and Consensus Conference

BACKGROUND

Outcomes after ileocolonic resection in Crohn's disease [CD] are heterogeneous, and a clear definition of postoperative recurrence remains to be determined. Our Endpoints Working Group of the International Organization for the study of Inflammatory Bowel Disease [IOIBD] aimed to standardise postoperative outcomes, to discuss which endpoints should be used for postoperative clinical trials, and to define those which could be used in trials or registries.

METHODS

Based on a systematic review of the literature, recommendations and statements were drafted and sent to all IOIBD members for a first round of voting. Recommendations and statements were revised based on the voters' comments during a consensus hybrid conference open to all IOIBD members. If no agreement was reached after two rounds of voting, the statement was excluded.

RESULTS

In the systematic review, 3071 manuscripts were screened of which 434 were included. Sixteen recommendations were identified, of which 11 were endorsed. Recommendations and statements include that endoscopy remains the gold standard and should be used as a short-term primary endpoint in both observational cohorts and randomised controlled trials. Clinical symptoms classically used in clinical trials for luminal CD are not reliable in this specific situation. For that reason, longer-term endpoints should be based on the evidence of macroscopic inflammation assessed by imaging techniques, endoscopy, or as reflected by the presence of complications.

CONCLUSIONS

Agencies recommend the use of clinical evaluations, as in the case of luminal CD, and do not recognise primary endpoints based solely on endoscopy. This consensus has led to agreement on the need to define postoperative endoscopy-based and/or imaging-based endpoints.

Assessing Active Bowel Inflammation in Crohn's Disease Using Intestinal Ultrasound: Correlation With Fecal Calprotectin

AIM

To analyze the correlation between intestinal ultrasound (IUS) and serum and fecal biomarkers, and the characteristics of small bowel disease, for the assessment of active bowel inflammation.

METHODS

Patients with Crohn's disease (CD) who underwent an initial IUS examination between July 2018 and November 2022 at our institution were included retrospectively. We divided small and large bowels into seven segments, and recorded the presence of active inflammation according to following criteria: bowel wall thickness ≥ mm with ≥1 of feature of active disease on IUS. The correlations between IUS-assessed activity and serum C-reactive protein (CRP, mg/dL) and fecal calprotectin (FC, μg/g) levels were analyzed.

RESULTS

A total of 127 patients were included (mean age: 32.42 ± 12.07, M:F = 90:37, median disease duration 6 years [0-35]). Of them, 78 showed active bowel inflammation (61.4%), with inflammation distal to the terminal ileum being the most common disease location (n = 61, 78.2%). FC and serum CRP levels were significantly correlated with the number of segments with active inflammation (rho = 0.58, 0.48), number of segments with complications (r = 0.35, 0.31), and US activity score (r = 0.62, 0.54). With FC cutoff values of 100 and 150 μg/g, the concordance rates for patients with active small bowel disease were 78.7% (26/33) and 72.7% (24/33), respectively, which were better than those for other disease locations.

CONCLUSIONS

Disease activity determined by IUS was significantly correlated with the biomarkers, with a better concordance rate in patients with active small bowel disease than in those with other disease locations with FC cut-off values of 100 and 150 μg/g.

Noninvasive Assessment of Postoperative Disease Recurrence in Crohn's Disease: A Multicenter, Prospective Cohort Study on Behalf of the Italian Group for Inflammatory Bowel Disease

BACKGROUND & AIMS

Colonoscopy (CS) is the gold standard to assess postoperative recurrence (POR) in Crohn's disease (CD). However, CS is invasive and may be poorly tolerated by patients. The aim of this study was to prospectively assess the diagnostic accuracy of a noninvasive approach in detecting POR, using the endoscopic Rutgeerts' score (RS) as the reference standard.

METHODS

Consecutive patients with CD who underwent ileo-cecal resection were prospectively enrolled in 3 referral Italian centers. Patients underwent CS and bowel ultrasound within 1 year of surgery. Uni- and multivariable analyses were used to assess the correlation between noninvasive parameters and endoscopic recurrence, defined by a RS ≥2.

RESULTS

Ninety-one patients were enrolled. Sixty patients (66%) experienced endoscopic POR. The multivariable analysis identified bowel wall thickness (BWT) per 1-mm increase (odds ratio [OR], 2.43; 95% confidence interval [CI], 1.21-4.89; P = .012), the presence of mesenteric lymph nodes (OR, 15.63; 95% CI, 1.48-164.54; P = .022), and fecal calprotectin (FC) values ≥50 mcg/g (OR, 8.58; 95% CI, 2.45-29.99; P < .001) as independent predictors for endoscopic recurrence. The presence of lymph nodes or the combination of BWT ≥3 mm and FC values ≥50 mcg/g correctly classified 56% and 75% of patients, with less than 5% of patients falsely classified as having endoscopic recurrence. Conversely, the combination of BWT <3 mm and FC <50 mcg/g correctly classified 74% of patients with only 4.5% of patients falsely classified as not having endoscopic recurrence.

CONCLUSIONS

A noninvasive approach combining bowel ultrasound and FC can be used with confidence for detecting POR in patients with CD without the requirement for CS.

Results of the Eighth Scientific Workshop of ECCO: Diagnosing Postoperative Recurrence of Crohn's Disease After an Ileocolonic Resection With Ileocolonic Anastomosis

Despite the introduction of potent biologic therapies, many patients with Crohn's disease [CD] still require an ileocolonic resection [ICR] during the course of their disease. Furthermore, the need of redo ICR has not decreased over the past few decades, highlighting the need for better strategies to prevent and treat postoperative recurrence [POR]. The first step to develop such a strategy would be to define and standardise the description of POR with adequate diagnostic instruments. In this article, we will describe the different methodologies used to report POR [endoscopic, histological, radiological, biochemical, clinical, and surgical], and review their potential benefits and limitations, as well as the optimal timing of evaluation.

Use of imaging modalities for decision-making in inflammatory bowel disease

Cross-sectional magnetic resonance enterography (MRE) and intestinal ultrasonography (IUS) provide valuable and noninvasive information to accurately assess disease activity, severity, and extent; detect complications; and monitor the response to treatment, as well as predict the postoperative recurrence of Crohn's disease and a negative disease course. Therefore, both imaging modalities are emerging as pivotal diagnostic tools to achieve the emerging therapeutic target of transmural healing associated with better disease outcomes. Despite its numerous potential advantages over endoscopy and even MRE and its good availability, IUS is still widely underused to monitor and manage inflammatory bowel disease (IBD) patients and help in making clinical decisions in routine practice. This situation is clearly due to the absence of validated, reliable, and responsive indices, as well as the lack of trained gastroenterologists and radiologists, as IUS is a component of radiologist expertise in several countries but not yet integrated into the training program of gastroenterologists. However, there is an increasing body of evidence in the literature that IUS and MRE are both becoming essential imaging resources to help clinicians in making reliable decisions. Here, we discuss the up-to-date evidence about the usefulness and performance of cross-sectional imaging, focusing on the ability of bowel US and MRE to aid clinical decision-making for the optimal management and monitoring of IBD.

Intestinal Ultrasound in the Assessment of Luminal Crohn’s Disease

Crohn’s disease is a chronic inflammatory disease affecting the gastrointestinal tract. Expert guidelines now recommend regular objective assessments as part of a treat-to-target approach. Intestinal ultrasound provides a noninvasive, patient-friendly modality for assessing Crohn’s disease without the risk of radiation exposure and does not require fasting or bowel preparation. Enhancement techniques, including oral and intravenous contrast, can improve disease-activity and complication detection. Due to its acceptability, intestinal ultrasound can be performed frequently, allowing for closer disease-activity monitoring and treatment adjustments. There have been significant advances in the utility of intestinal ultrasound; particularly for assessing disease activity during pregnancy and fibrosis detection utilising elastography. This review provides a comprehensive overview of performing intestinal ultrasound, the diagnostic accuracy, role in disease-activity monitoring, and recent advances in utilising ultrasound for the assessment of luminal Crohn’s disease.

Treat to transmural healing: how to incorporate intestinal ultrasound into the treatment of inflammatory bowel disease

Intestinal ultrasound (IUS) is emerging as a key tool to achieving the therapeutic target of transmural healing in inflammatory bowel disease (IBD). IUS is a non-invasive, radiation-free, imaging modality comparable to MRI, CT and ileocolonoscopy (IC). With the appropriate training and equipment, IUS can be an easily repeatable bedside test for IBD diagnosis and disease monitoring, including treatment response. Core to successful high quality IUS employment are appropriate training and expert techniques; however, the training pathway will not be explored in this review. Given the increasing shift towards objective assessment for tight disease control, gastroenterologist-led IUS should be incorporated into the armamentarium of imaging modalities alongside radiologists, to enhance our diagnostic and monitoring toolbox. This comprehensive review aims to outline the current literature around IUS and propose the placement of IUS in a treat-to-target algorithm in IBD. Ultimately, IUS facilitates timely management decisions to optimise patient care with potential to revolutionise patient outcomes, moving towards transmural healing as the holy grail of therapy in IBD.

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.

Predictivity of early and late assessment for post-surgical recurrence of Crohn's disease: Data from a single-center retrospective series

BACKGROUND AND AIMS

Post-surgical recurrence of Crohn's disease (CD) after ileocolonic resection is common. Early identification of features associated with recurrence is a standard procedure of postoperative management, but the prognostic role of such features when detected at later time points is unclear. We compared the predictivity for Crohn's disease recurrence of common clinical-instrumental variables when assessed early (<12 months) or late (>36 months) after surgery.

METHODS

This retrospective study considered CD patients who had ileocolonic resection and were followed for a median of 7.6 years. Clinical characteristics, post-surgical therapy, endoscopy recurrence (Rutgeerts' score ≥i2) and ultrasound features were compared between subgroups who had a early or late post-surgical assessment. Univariate and multivariate analyses were done to identify variables associated with recurrence (clinical and surgical).

RESULTS

Of 201 patients, 70 (32%) had a early and 39 (19%) had a late post-surgical assessment. The Early and Late subgroups had similar clinical characteristics. Overall, clinical relapse was observed in 131 patients (66%), surgical relapse in 31 (16%), endoscopic recurrence in 149 (75%) and ultrasonographic recurrence in 132 (66%), without significant differences in frequencies between subgroups. By Cox proportional hazard regression, endoscopic recurrence was a significant predictor of clinical recurrence overall (HR=2.31, P = 0.002) and in the Early (HR=3.85, P = 0.002) but not Late subgroup.

DISCUSSION

The most informative postoperative CD assessment is the one done within the first year of surgery. Later endoscopic evaluations have no prognostic value and should be done only for clinical needs or for research purposes.

Impact of intestinal ultrasound on the management of patients with inflammatory bowel disease: how to apply scientific evidence to clinical practice

Technological improvements and growing sonographers' expertise boost the role of intestinal ultrasound (IUS) in assessing patients with inflammatory bowel diseases (IBD). Non-invasiveness, low cost and good reproducibility make IUS attractive. Leveraging on the Authors' long-term field experience, this review focuses on the IUS role in IBD patients' clinical management. For detecting IBD, particularly Crohn's disease, the IUS parameters - above all the evidence of a thickened bowel wall (BWT) - show very good diagnostic accuracy similar to that of MRI or CT scan. The standard IUS parameters are not accurate enough to detect inflammatory activity, but intravenous contrast-enhanced US (CEUS) is highly accurate in ruling active inflammation out. However, its routinely use remains limited in clinical practice and its parameters need standardization. IUS is accurate in detecting IBD main complications: in particular, fistulae and abscesses. As to stenosis the recent introduction of IUS-based elastographic techniques allows to differentiate prevalently inflammatory from highly fibrotic strictures. IUS proves valid also for monitoring IBD patients. In particular, the evidence of transmural healing, defined as BWT normalization, has got an important prognostic meaning, as associated with better long-term clinical outcomes. Post-surgery CD recurrence can be suggested by early IUS assessment.

Ultrasound vs Endoscopy, Surgery, or Pathology for the Diagnosis of Small Bowel Crohn's Disease and its Complications

BACKGROUND

In patients with inflammatory bowel disease, we strive to achieve mucosal healing, as this has been shown to decrease the risk of disease flares, hospitalization, and surgery. For this reason, we must use objective measures of mucosal healing to inform our clinical decision-making and can no longer rely on patient symptoms alone. Assessment of small bowel Crohn's disease (SBCD) is particularly challenging given its lack of accessibility via standard endoscopic techniques. Ultrasound (US) represents a readily available, cost-effective, minimally invasive, radiation-free alternative for the assessment of small bowel disease. In this study, we performed a systematic review to determine the accuracy of ultrasound in diagnosing SBCD and its complications as compared with endoscopic visualization, surgery, and/or pathology.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL. Prospective cohort studies published up to March 2017 were reviewed. References meeting all eligibility criteria were assessed at the full-text level by 2 independent reviewers. Sensitivity and specificity were collected where available.

RESULTS

A total of 2817 unique references were identified. Twenty-two studies were included. All studies were at low-moderate risk of bias based on the Quality Assessment of Diagnostic Accuracy Studies criteria. Transabdominal US (TAUS) yielded moderately high sensitivity and specificity for the diagnosis of SBCD and its postoperative recurrence. Detection was more accurate for severe postoperative recurrence. The diagnostic accuracy of US in stricture and abscess detection was high. Contrast enhancement improved the detection of abscess. Diagnostic detection of fistulas was of moderate accuracy. Entero-enteric fistulization and entero-mesenteric fistulization were most clearly identified.

CONCLUSIONS

Ultrasound can be used to diagnose SBCD in those with known or suspected Crohn's disease. It can be used to detect postoperative recurrence and can accurately identify abscesses and fistulas, especially with the aid of contrast enhancement.

Intravenous Contrast-Enhanced Ultrasound for Assessing and Grading Postoperative Recurrence of Crohn's Disease

PURPOSE

The aim was to investigate the contribution of contrast-enhanced ultrasound (CEUS) to improve the results of US in the evaluation of recurrence in postsurgical Crohn's disease (CD) and establish its role in the assessment of the severity.

METHODS

Anastomotic site was assessed in 108 postsurgical CD patients with B-mode, color Doppler and CEUS. Bowel wall thickness (WT), transmural complications or stenosis, color Doppler grade, and bowel wall contrast enhancement (BWCE)-using time-intensity curves-were correlated with endoscopic Rutgeerts score. A receiver operating characteristic (ROC) curve was built to establish the best cutoff to predict recurrence and the severity. A US scoring system was elaborated in order to determine the grade of recurrence.

RESULTS

Ileocolonoscopy detected recurrence in 90 (83.3%) subjects and severe recurrence in 62. WT ≥ 3 mm had an accuracy of 90.7% in the detection of endoscopic recurrence. The combination of parameters-WT ≥ 3 mm and BWCE (≥ 46%)-demonstrated similar accuracy (90.7%). A WT ≥ 5 mm showed the best specificity (100%) for the diagnosis of recurrence and a WT ≥ 6 mm the best specificity (95.7%) for the detection of severe recurrence. The combination of sonographic parameters-WT ≥ 6 mm or WT between 5 and 6 mm with BWCE ≥ 70%, or complications-obtained the best results grading the recurrence (sensitivity, specificity, and accuracy of 90.3%, 87%, and 88.9%, respectively).

CONCLUSIONS

US shows high sensitivity and specificity for the diagnosis of postsurgical recurrence. When combined with CEUS, it can improve the detection of severe recurrence.

Intestinal ultrasound and management of small bowel Crohn's disease

As Crohn's disease (CD) is predominantly located within the small bowel, imaging of the small bowel plays an intriguing role in the primary diagnosis as well as in the monitoring of patients with CD. Intestinal ultrasound (IUS) offers several advantages over endoscopy and other imaging modalities. Obvious advantages of IUS include noninvasiveness, rapid availability and cost effectiveness. IUS has been shown to have high accuracy in detecting small bowel CD and determining intra- and extramural complications such as stenoses, fistulae and abscesses. IUS has also been shown to be highly effective in determining postoperative disease recurrence and in follow up of patients under treatment. The following review summarizes current developments in the use of IUS for the detection of small bowel lesions and complications. The aim of this review is to suggest algorithms on how to use IUS in managing patients with small bowel CD in clinical practice. Suggested applications on the use of high frequency IUS in CD are extended by discussing new developments such as contrast-enhanced ultrasonography and elastography.

Gastrointestinal ultrasound in inflammatory bowel disease: an underused resource with potential paradigm-changing application

Evolution of treatment targets in IBD has increased the need for objective monitoring of disease activity to guide therapeutic strategy. Although mucosal healing is the current target of therapy in IBD, endoscopy is invasive, expensive and unappealing to patients. GI ultrasound (GIUS) represents a non-invasive modality to assess disease activity in IBD. It is accurate, cost-effective and reproducible. GIUS can be performed at the point of care without specific patient preparation so as to facilitate clinical decision-making. As compared with ileocolonoscopy and other imaging modalities (CT and MRI), GIUS is accurate in diagnosing IBD, detecting complications of disease including fistulae, strictures and abscesses, monitoring disease activity and detecting postoperative disease recurrence. International groups increasingly recognise GIUS as a valuable tool with paradigm-changing application in the management of IBD; however, uptake outside parts of continental Europe has been slow and GIUS is underused in many countries. The aim of this review is to present a pragmatic guide to the positioning of GIUS in IBD clinical practice, providing evidence for use, algorithms for integration into practice, training pathways and a strategic implementation framework.

Diagnostic Accuracy of Ultrasonography in the Detection of Postsurgical Recurrence in Crohn's Disease: A Systematic Review with Meta-analysis

BACKGROUND AND AIMS

The postoperative course of Crohn's disease (CD) is best predicted by ileocolonoscopy. Ultrasonography (US) has been proposed as indicator for postsurgical recurrence (PSR), but further confirmation is needed. We performed a systemic review with meta-analysis to assess the pooled diagnostic accuracy of US in the evaluation of PSR.

METHODS

The systematic review was performed in PubMed/MEDLINE, EMBASE, SCOPUS, and Cochrane databases to identify studies assessing the US accuracy in PSR diagnosis. A sub-analysis between bowel sonography (BS), small-intestine contrast ultrasound (SICUS), and contrast-enhanced ultrasound (CEUS) was performed. Pooling was performed using diagnostic fixed or random-effect model according with heterogeneity.

RESULTS

Ten studies (536 patients) met the inclusion criteria. There was no publication bias. Pooled sensitivity and specificity of US in detecting PSR were 0.94 (95% CI, 0.86-0.97) and 0.84 (95% CI, 0.62-0.94; diagnostic accuracy 90%), respectively. At sub-analysis, pooled sensitivity and specificity were 0.82 (95% CI, 0.76-0.88) and 0.88 (95% CI, 0.74-0.95) respectively for BS, with 0.99 (95% CI, 0.99-1.00) and 0.74 (95% CI, 0.73-0.74) for SICUS. Finally, an SROC curve was built to establish the best bowel wall thickness (BWT) cutoff able to predict the presence of severe PSR (Rutgeerts ≥3): a BWT ≥5.5 mm at US revealed sensitivity of 83.8% (95% CI, 73.6%-90.6%), specificity of 97.7% (95% CI, 93%-99%).

CONCLUSIONS

US shows high sensitivity and specificity for the diagnosis of PSR. SICUS appears more sensitive-but less specific-than BS, while the role of CEUS needs further investigation. A cutoff value of BWT ≥5.5 mm is strongly indicative of severe PSR. 10.1093/ibd/izy012_video1izy012.video15775249754001.

Capsule Endoscopy, Magnetic Resonance Enterography, and Small Bowel Ultrasound for Evaluation of Postoperative Recurrence in Crohn's Disease: Systematic Review and Meta-Analysis

BACKGROUND

Anastomotic recurrence is frequent in patients with Crohn's disease (CD) following ileocecal resection. The degree of endoscopic recurrence, quantified by the Rutgeerts score (RS), is correlated with the risk of clinical and surgical recurrence. Noninvasive modalities such as capsule endoscopy (CE), magnetic resonance enterography (MRE), and intestinal ultrasound (US) may yield similar information without the need for ileocolonoscopy (IC). The aim of our meta-analysis was to evaluate the accuracy of those modalities for detection of endoscopic recurrence in postoperative CD patients.

METHODS

We performed a systematic literature search for studies comparing the accuracy of CE, MRE, and US with IC for detection of postoperative recurrence in CD. We calculated pooled diagnostic sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) for each comparison.

RESULTS

A total of 135 studies were retrieved; 14 studies were eligible for analysis. For CE, the pooled sensitivity was 100% (95% CI, 91%-100%), specificity was 69% (95% CI, 52%-83%), DOR was 30.8 (95% CI, 6.9-138), and AUC was 0.94. MRE had pooled sensitivity of 97% (95% CI, 89%-100%), specificity of 84% (95% CI, 62%-96%), DOR of 129.5 (95% CI, 16.4-1024.7), and AUC of 0.98. US had pooled sensitivity of 89% (95% CI, 85%-92%), specificity of 86% (95% CI, 78%-93%), DOR of 42.3 (95% CI, 18.6-96.0), and AUC 0.93.

CONCLUSIONS

CE, MRE, and US provide accurate assessment of postoperative endoscopic recurrence in CD. These modalities should gain wider use for detection of postoperative recurrence; the prognostic value of those diagnostic findings merits evaluation in further prospective studies.

NASPGHAN Clinical Report on Postoperative Recurrence in Pediatric Crohn Disease

Pediatric Crohn disease is characterized by clinical and endoscopic relapses. The inflammatory process is considered to be progressive and may lead to strictures, fistulas, and penetrating disease that may require surgery. In addition, medically refractory disease may be treated by surgical resection of inflamed bowel in an effort to reverse growth failure. The need for surgery in childhood suggests severe disease and these patients have an increased risk for recurrent disease and potentially more surgery. Data show that up to 55% of patients had clinical recurrence in the first 2 years after initial surgery. The current clinical report on postoperative recurrence in pediatric Crohn disease reviews the risk factors for early surgery and postoperative recurrence, operative risk factors for recurrence, and prevention and monitoring strategies for postoperative recurrence. We also propose an algorithm for postoperative management in pediatric Crohn disease.

Role of Bowel Ultrasound in the Diagnosis and Follow-up of Patients with Crohn's Disease

Crohn's disease (CD) is an inflammatory chronic bowel disorder; it can involve the whole gastrointestinal tract, but its localization in the ileum or colon is most common. The reference standard for the diagnosis of CD is ileocolonoscopy with histologic assessment. The reference standard for the detection of any complications is surgery. However, imaging techniques have an important role both in the detection/localization of CD and in the follow-up of CD patients. In the last few years, the technical development of ultrasound equipment, the advent of new technologies such as elastography and mostly the increased expertise of sonographers have boosted the role of bowel ultrasound in assessment of the gastrointestinal tract. In fact, bowel ultrasound is particularly attractive thanks to its widespread availability, non-invasiveness, low cost and good reproducibility, as it can be easily repeated during follow-up. The aim of this article is to provide an extensive overview of the actual role of bowel ultrasound in the detection and follow-up of patients with CD.

Splenic CD4+ T Cells in Progressive Visceral Leishmaniasis Show a Mixed Effector-Regulatory Phenotype and Impair Macrophage Effector Function through Inhibitory Receptor Expression

Visceral leishmaniasis (VL), caused by infection with the intracellular protozoan Leishmania donovani, is a chronic progressive disease with a relentlessly increasing parasite burden in the spleen, liver and bone marrow. The disease is characterized by fever, splenomegaly, cachexia, and pancytopenia, and progresses to death if not treated. Control of Leishmania infection is mediated by Th1 (IFNγ-producing) CD4+ T cells, which activate macrophages to produce nitric oxide and kill intracellular parasites. However, despite expansion of CD4+ T cells and increased IFNγ expression in the spleen, humans with active VL do not control the infection. We used an experimental model of chronic progressive VL in hamsters, which mimics clinical and pathological features seen in humans, to better understand the mechanisms that lead to progressive disease. Transcriptional profiling of the spleen during chronic infection revealed expression of markers of both T cell activation and inhibition. CD4+ T cells isolated from the spleen during chronic progressive VL showed mixed expression of Th1 and Th2 cytokines and chemokines, and were marginally effective in controlling infection in an ex vivo T cell-macrophage co-culture system. Splenic CD4+ T cells and macrophages from hamsters with VL showed increased expression of inhibitory receptors and their ligands, respectively. Blockade of the inhibitory receptor PD-L2 led to a significant decrease in parasite burden, revealing a pathogenic role for the PD-1 pathway in chronic VL. PD-L2 blockade was associated with a dramatic reduction in expression of host arginase 1, but no change in IFNγ and inducible nitric oxide synthase. Thus, the expression of counter-regulatory molecules on splenic CD4+ T cells and macrophages promotes a more permissive macrophage phenotype and attenuates intracellular parasite control in chronic progressive VL. Host-directed adjunctive therapy targeting the PD-1 regulatory pathway may be efficacious for VL.

SICUS and CEUS imaging in Crohn's disease: an update

Endoscopy remains the main technique in the diagnosis and treatment of Crohn's disease (CD); nevertheless, the recent development of innovative and non-invasive imaging techniques has led to a new tool in the exploration of small bowel in CD patients. This paper reviews the available data on ultrasound imaging used for the evaluation of CD, highlighting the role of small intestine contrast-enhanced ultrasonography with the use of oral and intravenous contrast agents.

The use of ultrasound in inflammatory bowel disease

Imaging in inflammatory bowel disease (IBD) plays a pivotal role in the primary diagnosis, as well as during the management of patients with known IBD. The evolution of ultrasound equipment and the growing expertise of examiners have both enhanced the role of intestinal ultrasound in the assessment of the gastrointestinal tract in IBD patients. Intestinal ultrasound has been shown to have high sensitivity and specificity, as well as high positive and negative predictive value, in the detection or exclusion of intestinal inflammatory activity in IBD. The obvious advantages of intestinal ultrasound over other imaging modalities include non-invasiveness, rapid availability and low costs. This review summarizes the current developments in the use of intestinal ultrasound for the detection of IBD and its complications, and discusses its use in the management of patients with IBD. Indications for the use of intestinal ultrasound in daily practice are presented, expanded by new developments such as contrast-enhanced ultrasonography and elastography.

Evolving roles of cross-sectional imaging in Crohn's disease

The implementation of cross-sectional imaging techniques for the clinical management of Crohn's disease patients has steadily grown over the recent years, thanks to a series of technological advances, including the evolution of contrast media for magnetic resonance, computed tomography and bowel ultrasound. This has resulted in a continuous improvement of diagnostic accuracy and capability to detect Crohn's disease-related complications. Additionally, a progressive widening of indications for cross-sectional imaging in Crohn's disease has been put forward, thus leading to hypothesize that in the near future imaging techniques can increasingly complement endoscopy in most clinical settings, including the grading of disease activity and the assessment of mucosal healing or Crohn's disease post-surgical recurrence.

Medical Imaging in Small Bowel Crohn's Disease-Computer Tomography Enterography, Magnetic Resonance Enterography, and Ultrasound: "Which One Is the Best for What?"

BACKGROUND

Small bowel imaging in Crohn's disease (CD) is an important adjunct to endoscopy for the diagnosis, assessment of postoperative recurrence, and detection of complications. The best imaging modality for such indications though remains unclear. This systematic review aims to identify the imaging modality of choice considering the use of ultrasound (US), computed tomography enterography (CTE), and magnetic resonance enterography (MRE).

METHODS

Databases were systematically searched for studies pertaining to the performance of US, CTE, and MRE, as compared with a predefined reference standard in the assessment of small bowel CD.

RESULTS

Thirty-three studies, from a total of 1427 studies, were included in the final analysis. A comparable performance was demonstrated for MRE, CTE, and US for the diagnosis of small CD. Ultrasound was found to have the highest accuracy in the differentiation of inflammation and fibrosis. Postoperative recurrence detection was feasible with the use of MRE and US. All 3 modalities were shown to have a role in the detection of small bowel CD complications. The radiation exposure associated with CTE can be minimized by using lower radiation protocols.

CONCLUSIONS

Ultrasound, CTE, and MRE all play an important role in the diagnosis and management of small bowel CD, with preference for a particular modality being influenced by specific indication, institution resources, and patient preference.

Bowel Ultrasonography in the Management of Crohn's Disease. A Review with Recommendations of an International Panel of Experts

BACKGROUND

Bowel ultrasonography (US) is considered a useful technique for assessing mural inflammation and complications in Crohn's disease (CD). The aim of this review is to appraise the evidence on the accuracy of bowel US for CD. In addition, we aim to provide recommendations for its optimal use.

METHODS

Publications were identified by literature search from 1992 to 2014 and selected based on predefined criteria: 15 or more patients; bowel US for diagnosing CD, complications, postoperative recurrence, activity; adequate reference standards; prospective study design; data reported to allow calculation of sensitivity, specificity, agreement, or correlation values; articles published in English.

RESULTS

The search yielded 655 articles, of which 63 were found to be eligible and retrieved as full-text articles for analysis. Bowel US showed 79.7% sensitivity and 96.7% specificity for the diagnosis of suspected CD, and 89% sensitivity and 94.3% specificity for initial assessment in established patients with CD. Bowel US identified ileal CD with 92.7% sensitivity, 88.2% specificity, and colon CD with 81.8% sensitivity, 95.3% specificity, with lower accuracy for detecting proximal lesions. The oral contrast agent improves the sensitivity and specificity in determining CD lesions and in assessing sites and extent.

CONCLUSIONS

Bowel US is a tool for evaluation of CD lesions in terms of complications, postoperative recurrence, and monitoring response to medical therapy; it reliably detects postoperative recurrence and complications, as well as offers the possibility of monitoring disease progression.

Diagnosis and monitoring of postoperative recurrence in Crohn's disease

Despite advances in medical management, many patients with Crohn's disease (CD) require intestinal surgery throughout their lives. Surgery is not a cure, and postoperative recurrence is common in patients with CD. Ileocolonoscopy has been considered to be the gold standard in the diagnosis and monitoring of postoperative recurrence. However, the optimal monitoring strategy for postoperative recurrence has yet to be established. Capsule endoscopy and cross-sectional imaging techniques, including ultrasonography, computed tomography and MRI, have been used in the postoperative setting, and their usefulness in the monitoring of disease activity has been evaluated in recent clinical trials. The value of fecal markers, such as calprotectin and lactoferrin, has been also assessed in several studies. This review was to identify optimized methods for the diagnosis and monitoring of postoperative recurrence in CD.

Imaging techniques in IBD and their role in follow-up and surveillance

The assessment of extent and severity of IBD is crucial for directing treatment decisions. Clinical symptoms alone are neither sensitive nor specific for the assessment of lesion severity in IBD. Cross-sectional imaging techniques, as well as small-bowel capsule endoscopy (SBCE) and device-assisted enteroscopy, have a high accuracy for assessing the extent of mucosal lesions, and are reliable alternatives to ileocolonoscopy. New endoscopic techniques and devices are emerging for improved follow-up and surveillance. In this Review, we discuss different imaging techniques that are used to assess IBD activity and to survey patients with IBD, and highlight the latest developments in each area. Moreover, technical improvements and new tools that aim to measure intestinal fibrosis, postoperative recurrence, activity indices and endoscopic features are analysed. All of these imaging techniques are aimed at changing the paradigm from symptom-driven to lesion-driven treatment of IBD.

Bowel perfusion measured with dynamic contrast-enhanced ultrasound predicts treatment outcome in patients with Crohn's disease

BACKGROUND

To improve management of patients with Crohn's disease (CD), objective measurements of the degree of local inflammation in the gastrointestinal wall are needed. Increased microvessel density and perfusion are typical features of acute inflammation and can be estimated with contrast-enhanced ultrasound (CEUS). The aim of the study was to investigate whether CEUS can provide prognostic information about patients treated medically for an acute exacerbation of CD.

METHODS

Fourteen patients with CD who received medical treatment for acute exacerbation with systemic steroids or tumor necrosis factor-α inhibitors were prospectively recruited. The patients were examined with clinical scoring, blood tests, and CEUS at time 0, 1, 3, and 12 months after initiation of the treatment. Outcome was treatment efficacy or treatment failure defined as change in medical treatment after 1 month or later. The perfusion analysis was performed with a commercially available software program that analyzes the contrast intensity in a selected area, fits the data to a standardized time-intensity curve, and derives several relative perfusion parameters.

RESULTS

Six of the 14 patients had treatment failure during the study period. There was a significant difference between the groups for peak contrast enhancement (P = 0.013), rate of wash-in (P = 0.020) and wash-out (P = 0.008), and the area under the time-intensity curve in the wash-in phase (0.013) at the examination 1 month after the start of treatment.

CONCLUSIONS

Perfusion analysis of the intestinal wall with CEUS 1 month after starting treatment in patients with CD can provide prognostic information regarding treatment efficacy.

Usefulness of abdominal ultrasonography in the analysis of endoscopic activity in patients with Crohn's disease: changes following treatment with immunomodulators and/or anti-TNF antibodies

OBJECTIVE

The objective of this study was to analyze the accuracy of abdominal ultrasonography (AUS) in the assessment of mucosal healing in patients with Crohn's disease (CD) receiving immunomodulators and/or biological treatment, with ileocolonoscopy as the reference standard.

MATERIALS AND METHODS

Thirty patients were included in a prospective longitudinal study. All patients underwent ileocolonoscopy and AUS before and after a minimum of one year of treatment. The Crohn's Disease Endoscopic Inflammatory Index of Severity (CDEIS) was used for endoscopic assessment whereas AUS was analyzed by means of bowel wall thickness, color Doppler grade and percentage of increase of parietal enhancement after contrast injection.

RESULTS

In the segmental analysis, endoscopic healing was found in 71.2% of the segments and AUS findings were normalized in 62.8%, with a significant correlation between the two techniques (κ=0.76, p<0.001). In the overall assessment performed after treatment, 18 (60%) patients exhibited endoscopic remission (CDEIS <6 points); of these patients, 15 (83.3%) had normalized sonographic findings, with a good correlation between endoscopic remission and sonographic normalization (κ=0.73, p<0.001). Of the three variables assessed by AUS, parietal thickness was the best variable to predict mucosal healing in both analyses, segmental and global.

CONCLUSION

Abdominal ultrasonography is a useful and reliable technique for the assessment of the endoscopic response to treatment with immunomodulators and/or biological drugs in Crohn's disease. AUS is a highly accurate technique for evaluating the healing of the intestinal mucosa.

Ultrasound as a diagnostic tool in detecting active Crohn's disease: a meta-analysis of prospective studies

OBJECTIVES

To evaluate the diagnostic accuracy of ultrasound in assessing active Crohn's disease (CD) in adults.

METHODS

We systematically searched PubMed, EMBASE, Web of Science and the Cochrane Library for prospective studies in which ultrasound was performed to evaluate active CD in adults from January 1993 to April 2013. Pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-) and diagnostic odds ratios (DORs) in a per-patient-based analysis were estimated. Additionally, the area under the receiver-operating characteristic (ROC) curve was calculated to measure the diagnostic accuracy of ultrasound in patients with known or suspected CD.

RESULTS

Fifteen studies involving 1,558 patients were included in this meta-analysis. Overall, the pooled sensitivity (0.88) and LR- (0.14) were not heterogeneous, whereas the pooled specificity (0.97, I(2) = 72.9 %) and LR + (15.10, I(2) = 71.8 %) were. The DOR of ultrasound for assessing active CD was 121.70, with significant heterogeneity (I(2) = 63.3 %). A symmetrical summary ROC curve was plotted showing that the area under the curve was 0.94, indicating good diagnostic accuracy. Meta-regression and subgroup analysis showed that the disease location may be a major cause of heterogeneity.

CONCLUSIONS

This meta-analysis suggests that ultrasound has high diagnostic accuracy in detecting active CD in adults, especially for small bowel CD.

KEY POINTS

• Ultrasound can detect active Crohn's disease (CD). • A meta-analysis of ultrasound for detecting active CD was carried out. • This revealed that ultrasound has high diagnostic accuracy for detecting CD.

Crohn's disease recurrence in patients with ileocolic anastomosis: value of computed tomography enterography with water enema

OBJECTIVES

The main objective of the present work was to determine the diagnostic value of CT-enterography with water enema (CTe-WE) in the assessment of the ileocolic anastomosis in patients with Crohn's disease (CD). The prevalence of synchronous inflammatory lesions (SILs) involving gastrointestinal segments distinct from the anastomosis was also determined. Further, the association between the type of ileocolic anastomosis and the behavior (i.e. inflammatory, stricturing, penetrating) of CD recurrence was evaluated.

METHODS

51 patients were retrospectively included (26 [51%] male and 25 [49%] female; mean age: 52.88 years ± 13.35). Ileocolic anastomoses were: 18 (35.3%) stapled side-to-side, 17 (33.3%) end-to-side, and 16 (31.4%) end-to-end. CTe-WEs were reviewed in consensus by two gastrointestinal radiologists. Endoscopy and medical records were used as reference standards.

RESULTS

CTe-WE yielded 95.35% sensitivity (CI 95%: 84.19-99.43%), 75.00% specificity (CI 95%: 34.91-96.81%), and 92.15% diagnostic accuracy (CI 95%: 81.31-98.02%). Anastomotic recurrence was found in 41/51 (80.4%) patients, including 30/41 (73.2%) cases of isolated anastomotic recurrence, and 11/41 (26.8%) cases of anastomotic recurrence with a SIL. A significant lower prevalence of stricturing recurrence was observed in patients with stapled side-to-side anastomoses (p=0.033).

CONCLUSIONS

CTe-WE provides a good distension of both sides of ileocolic anastomoses allowing the detection of SILs.

Role of bowel ultrasound as a predictor of surgical recurrence of Crohn's disease

BACKGROUND

In Crohn's disease natural history, about 80% of the patients require surgery, which is not curative: unfortunately, the disease recurs in many patients.

OBJECTIVE

To investigate the role of intestinal ultrasound to predict the risk of post-operative surgical recurrence in Crohn's disease.

MATERIAL AND METHODS

A total of 196 patients, with ileal or ileocolonic Crohn's disease, undergoing intestinal resection, were retrospectively enrolled. All patients underwent bowel ultrasonography 6-15 months after resection. Wall thickness at the anastomosis level was measured, and thickening >3 mm was evaluated as risk factor of long-term need for reoperation.

RESULTS

Patients who have a bowel wall thickness >3 mm have an risk ratio (RR) of surgical recurrence = 2.1 [95% confidence interval (CI) = 1.12-3.74] higher than those with a thickness of ≤3 mm. The absolute incidence of new surgical intervention is 13% in patients with thickness of 3 mm, 28% in patients with thickness >3 mm, 29,1% with thickness >4 mm, 34% with thickness >5 mm, and 40% with thickness >6 mm.

CONCLUSIONS

Bowel wall thickness >3 mm at ultrasound may be a non-invasive predictor of early surgical recurrence after ileo-colonic resection.

Contrast-enhanced ultrasonography: usefulness in the assessment of postoperative recurrence of Crohn's disease

AIM

The aim of this study was to assess whether the contrast-enhanced ultrasonography (CEUS) can increase the value of the ultrasonography in the study of postoperative recurrence of Crohn's disease (CD).

MATERIALS AND METHODS

60 patients with CD who had previously undergone ileocolic resection underwent prospectively both CEUS and colonoscopy within a 3-day period. The sonographic examination included evaluation of bowel wall thickness, transmural complications, colour Doppler grade and contrast-enhanced US. In addition a sonographic score was established. The capacity of CEUS to diagnose endoscopic recurrence, as well as its severity, was assessed by calculating the sensitivity, specificity and positive and negative predictive values, accuracy and odds ratio, with their respective 95% confidence intervals. The areas under the receiver operating characteristic (ROC) curves were also calculated.

RESULTS

49 out of 60 patients showed endoscopic postoperative recurrence. Severe endoscopic recurrence was present in 34 patients (57%). Classic ultrasound parameters (wall thickness >3mm and colour Doppler flow) revealed an accuracy of 88.3% for the diagnosis of recurrence. Sonographic score 2, including thickness >5mm or contrast enhancement >46%, improved the results with a sensitivity, specificity and accuracy of 98%, 100% and 98.3%, respectively, in the diagnosis of endoscopic recurrence. The area under the ROC curve was 0.99, in remarkable agreement with endoscopy (k: 0.946). Sonographic score 3, including thickness >5mm, contrast enhancement >70% or fistula identified 32 out of 34 (94.1%) severe endoscopic recurrences. The area under the ROC curve was 0.836, in good agreement with endoscopy (k: 0.688).

CONCLUSION

CEUS shows excellent sensitivity and specificity for the diagnosis of postoperative recurrence in CD and can also detect severe recurrences.

Mucosal healing in Crohn's disease: a systematic review

The traditional goals of Crohn's disease therapy, to induce and maintain clinical remission, have not clearly changed its natural history. In contrast, emerging evidence suggests that achieving and maintaining mucosal healing may alter the natural history of Crohn's disease, as it has been associated with more sustained clinical remission and reduced rates of hospitalization and surgical resection. Induction and maintenance of mucosal healing should therefore be a goal toward which therapy is now directed. Unresolved issues pertain to the benefit of achieving mucosal healing at different stages of the disease, the relationship between mucosal healing and transmural inflammation, the intensity of treatment needed to achieve mucosal healing when it has not been obtained using standard therapy, and the means by which mucosal healing is defined using current endoscopic disease activity indices. The main clinical challenge relates to defining the means of achieving high rates of mucosal healing in clinical practice.

Ileal Crohn's disease: CEUS determination of activity

Transabdominal ultrasound is currently accepted as a clinical first-line tool in the assessment of Crohn's disease activity. During recent years, great improvements have been achieved in ultrasound examination with the introduction of high-frequency transducers, ultrasonographic microbubble contrast agents, and dedicated contrast-specific ultrasound software. Therefore, contrast-enhanced ultrasonography (CEUS) is emerging as one of the most important imaging techniques in the diagnosis and follow-up of patients with ileal Crohn's disease. It is non-invasive and non-ionizing, easily repeatable, well-tolerated by patients and has significant diagnostic accuracy. Moreover, the possibility to monitor response to therapies, describing, and quantifying contrast enhancement behavior by specific software, represents an interesting aspect of its utilization, considering the still open questions about the correct use of immunosuppressive and biological agents. The aim of our review is to provide an updated overview of the role of CEUS in the patients who have an ileal localization of Crohn's disease, defining its qualitative and quantitative features.

Diagnosis, prevention and treatment of postoperative Crohn's disease recurrence

Ileocolonoscopy remains the gold standard in diagnosing postoperative recurrence. After excluding stricture, wireless capsule endoscopy seemed accurate in small series, but no validated score is available. Ultrasonography is a non-invasive diagnostic method reducing radiation exposure and emerging as an alternative tool for identifying post-operative recurrence. Computed tomography enteroclysis yields objective morphologic criteria that help differentiate between recurrent disease and fibrostenosis at the anastomotic site, but ionising radiation exposure limits its use. Magnetic resonance imaging may be as powerful as ileocolonoscopy in diagnosing postoperative recurrence and in predicting the clinical outcome using specific MR-scores. Biomarkers such as faecal calprotectin and faecal lactoferrin showed promising results, but their specificity in the postoperative period will require further investigation. Numerous medications have been tested to prevent and/or to treat postoperative recurrence. Efficacy of mesalamine is very low and comparable to placebo in most series. Thiopurines have modest efficacy in the postoperative setting and are associated with a high rate of adverse events leading to drug withdrawal. Antibiotics such as metronidazole or ornidazole may be effective, but toxicity and drug resistance prevent their long-term use. Anti-Tumour Necrosis Factor therapy is the most potent drug class to prevent and to treat postoperative recurrence in Crohn's disease.

Postoperative recurrent luminal Crohn's disease: a systematic review

Despite improved immunosuppressive therapy, surgical resection is still often required for uncontrolled inflammatory disease and the stenosing and perforating complications of Crohn's disease. However, surgery is not curative. A majority of patients develop disease recurrence at or above the anastomosis. Subclinical endoscopically identifiable recurrence precedes the development of clinical symptoms; identification and treatment of early mucosal recurrence may therefore prevent clinical recurrence. Therapy to achieve mucosal healing should now be the focus of postoperative therapy. A number of clinical risk factors for the development of earlier postoperative recurrence have been identified, and reasonable evidence is now available regarding the efficacy of drug therapies in preventing recurrence. This evidence now needs to be incorporated into prospective treatment strategies.

Contrast-enhanced ultrasound (CEUS) in Crohn's disease: technique, image interpretation and clinical applications

BACKGROUND: Recent meta-analysis has demonstrated no significant differences in diagnostic accuracy among different imaging techniques (US, MRI and CT) in the evaluation of Crohn's disease (CD). High-resolution bowel ultrasound has emerged as an alternative imaging technique for the diagnosis and follow-up of patients with CD, being as accurate as CT and MR for detecting intramural and extramural extension of the disease. B-Mode US can evaluate the localization and length of the affected intestinal segments and allow identification of transmural complications, stenosis and intestinal obstruction. Doppler techniques are tools that visualize and quantify bowel vascularization. Contrast-enhanced ultrasound (CEUS) is a new technique that involves IV administration of an ultrasound contrast agent with real-time examination, providing an accurate depiction of the bowel wall microvascularization and the perienteric tissues. The introduction of imaging quantification techniques enables an objective quantitative measurement of the enhancement. METHOD AND RESULTS: The article reviews the technique, sonographic findings, advantages and limitations, and clinical applications of contrast-enhanced US in the evaluation of Cohn's disease. Current CEUS applications in CD are: CD activity assessment, evaluation of inflammatory masses, distinguishing phlegmons from abscesses, characterization of stenosis by differentiating fibrosis from inflammation, monitoring the efficacy of drug treatments and improving the detection of disease recurrence. CONCLUSION: CEUS is an emerging technique that is part of the entire sonographic evaluation, with a role in the diagnosis and follow-up of CD, thus improving therapy planning and monitoring of the efficacy of treatment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13244-011-0124-1) contains supplementary material, which is available to authorized users.

Systematic review: the use of ultrasonography, computed tomography and magnetic resonance imaging for the diagnosis, assessment of activity and abdominal complications of Crohn's disease

BACKGROUND

Cross-sectional imaging techniques, including ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI), are increasingly used for evaluation of Crohn's disease (CD). Aim  To perform an assessment of the diagnostic accuracy of cross-sectional imaging techniques for diagnosis of CD, evaluation of disease extension and activity and diagnosis of complications, and to provide recommendations for their optimal use.

METHODS

Relevant publications were identified by literature search and selected based on predefined quality parameters, including a prospective design, sample size and reference standard. A total of 68 publications were chosen.

RESULTS

Ultrasonography is an accurate technique for diagnosis of suspected CD and for evaluation of disease activity (sensitivity 0.84, specificity 0.92), is widely available and non-invasive, but its accuracy is lower for disease proximal to the terminal ileum. MRI has a high diagnostic accuracy for the diagnosis of suspected CD and for evaluation of disease extension and activity (sensitivity 0.93, specificity 0.90), and is less dependent on the examiner and disease location compared with US. CT has a similar accuracy to MRI for assessment of disease extension and activity. The three techniques have a high accuracy for identification of fistulas, abscesses and stenosis (sensitivities and specificities >0.80), although US has false positive results for abscesses. As a result of the lack of radiation, US or MRI should be preferred over CT, particularly in young patients.

CONCLUSIONS

Cross-sectional imaging techniques have a high accuracy for evaluation of suspected and established CD, reliably measure disease severity and complications; they may offer the possibility to monitor disease progression.

[Crohn's disease: the usefulness of MR enterography in the detection of recurrence after surgery]

OBJECTIVES

To determine the usefulness of MR enterography in the detection of recurrence in the ileocolonic anastomosis in patients with Crohn's disease that have undergone intestinal resection.

MATERIAL AND METHODS

We used MR enterography and ileocolonoscopy to study 30 patients with Crohn's disease who had undergone intestinal resection. To determine the degree of relapse, the findings at MR enterography were quantified using our own index of Crohn's disease activity and the findings at ileocolonoscopy were quantified using the Rutgeerts scale. Ileocolonoscopy was considered the gold standard.

RESULTS

Compared to the gold standard, MR enterography yielded 100% sensitivity, 60% specificity, 92.6% positive predictive value (PPV), 100% negative predictive value (NPV), and 93.3% diagnostic accuracy. The concordance between the degree of recurrence determined with MR enterography and with ileocolonoscopy was moderate (κ=0.41). However, when patients were classified into two groups (high or low grade) according to outcome and the possibility of repeat surgery, the concordance was excellent (κ=0.87). Using this classification, MR enterography had 85% sensitivity, 100% specificity, 100% PPV, and 76.9% NPV.

CONCLUSIONS

MR enterography is a useful imaging method for detecting recurrence of Crohn's disease after surgery and for differentiating between patients with higher or lower risk of poor outcome. MR enterography has good concordance with ileocolonoscopy and is an alternative to ileocolonoscopy in determinate occasions.

Non-invasive diagnosis and grading of postsurgical endoscopic recurrence in Crohn's disease: usefulness of abdominal ultrasonography and (99m)Tc-hexamethylpropylene amineoxime-labelled leucocyte scintigraphy

Non-invasive techniques aim to be an alternative to endoscopy in the assessment of postsurgical recurrence of Crohn's disease (CD). The object of this study was to evaluate the accuracy of abdominal ultrasonography (AUS) and (99m)Tc-hexamethylpropylene amineoxime ((99m)Tc-HMPAO)-labelled leucocyte scintigraphy (LLS) compared with endoscopy in the diagnosis and grading of postsurgical recurrence of CD. Between January 2006 and May 2007, all patients with CD and resection with ileocolic anastomosis were included prospectively. Within three days they underwent an ileocolonoscopy, AUS with evaluation of bowel wall thickness and the presence of Doppler flow, and LLS. Forty patients who met the study conditions were included; 5 patients did not agree to have the ileocolonoscopy and it was not possible to assess the anastomosis in 2 patients. Endoscopic recurrence was detected in 26 patients (78.8%), in 15 of whom it was moderate-severe. For the diagnosis of recurrence, both AUS and LLS showed acceptable sensitivity and positive predictive value, with an accuracy of 72.7% and 78.1%, respectively. The results of the AUS and LLS for diagnosing moderate-severe recurrence were better, with an accuracy of 78.8% and 81.3%, respectively. The best assessment of the severity of the recurrence was obtained with the combination of both techniques (sensitivity, specificity, positive and negative predictive values, accuracy and kappa index were, respectively: 93.3%, 72.2%, 73.7%, 92.9%, 81.8% and 0.64). The variables evaluated, both sonographic and scintigraphic, had areas under the curve that were similar and significantly different from 0.5.

CONCLUSION

Abdominal ultrasonography and (99m)Tc-HMPAO-labelled leucocyte scintigraphy are two useful non-invasive techniques for the assessment of postsurgical recurrence of Crohn's disease.

Ultrasonographic detection and assessment of the severity of Crohn's disease recurrence after ileal resection

BACKGROUND

Recurrence and severity of Crohn's disease mucosal lesions after "curative" ileal resection is assessed at endoscopy. Intramural lesions can be detected as increased wall thickness at Small Intestine Contrast Ultrasonography (SICUS).

AIMS

To assess after ileal resection whether: 1) SICUS detects recurrence of Crohn's disease lesions, 2) the intestinal wall thickness measured at the level of ileo-colonic anastomosis predicts the severity of endoscopic lesions, 3) the extension of intramural lesions of the neo-terminal ileum is useful for grading severity of the recurrence, 4) the combined measures of wall thickness of the ileo-colonic anastomosis and of the extension of intramural lesions at level of the neo-terminal ileum may predict the endoscopic Rutgeerts score

METHODS

Fifty eight Crohn's disease patients (M 37, age range 19-75 yrs) were prospectively submitted at 6-12 months intervals after surgery to endoscopy and SICUS for a total of 111 observations.

RESULTS

Six months or more after surgery wall thickness of ileo-colonic anastomosis > 3.5 mm identified 100% of patients with endoscopic lesions (p < 0.0001). ROC curve analysis, combining wall thickness of ileo-colonic anastomosis and the extension of intramural lesions of neo-terminal ileum, discriminated (0.95) patients with, from those without, endoscopic lesions. Performing two multiple logistic regression analyses only wall thickness of ileo-colonic anastomosis and extension of neo-terminal ileum intramural lesions were significantly associated with absence or presence of endoscopic lesions. An ordinal polychotomus logistic model, considering all investigated variables, confirmed that only SICUS variables were associated with endoscopic grading of severity.

CONCLUSIONS

In patients submitted to ileal resection for Crohn's disease non-invasive Small Intestine Contrast Ultrasonography 1) by assessing thickness of ileo-colonic anastomosis accurately detects initial, minimal Crohn's disease recurrence, and 2) by assessing both thickness of ileo-colonic anastomosis and extension of intramural lesions of neo-terminal ileum grades the severity of the post-surgical recurrence.

Ultrasound and inflammatory bowel disease

Transabdominal bowel sonography is a fast, efficient, and cheap way of examining the intestines. It is also virtually hazard-free and well accepted by patients. During the last 20 years, it has been established as a procedure for detecting bowel disease early in the diagnostic workup. Although rather unspecific, the method is sensitive for detection of bowel disease and can be applied to find the extent and location of inflammatory bowel disease. In patients with known ulcerative colitis and Crohn disease, it can also be used for follow-up because it is easily repeatable and radiation-free. Because it can be applied to find both intraluminal and peri-intestinal pathological features, it is a particularly valuable tool for the detection of complications of Crohn disease as stenosis, fistulas, and abscesses. Neither B-mode nor Doppler techniques have been proven obviously useful in categorizing disease activity, but new techniques using intravenous contrast might come closer to solving this question. Finally, recent longitudinal studies using transabdominal bowel sonography show that it can also give important prognostic information and be used for monitoring the effect of therapy.

Contrast-enhanced ultrasonographic evaluation of inflammatory activity in Crohn's disease

BACKGROUND & AIMS

We sought to test the diagnostic accuracy of ultrasound (US), color Doppler US (CD-US), and contrast-enhanced US (CE-US) in the evaluation of inflammatory activity in patients with Crohn's disease (CD), and to correlate the findings of these sonographic studies with inflammatory activity, as scored by the CD activity index (CDAI).

METHODS

Patients with CD were enrolled in the study. Radiologists performing the scans were blinded to clinical status. Baseline US, CD-US, and CE-US examinations were conducted with high-frequency probes (8-14 and 5-7 MHz) before and after injection of sulfur hexafluoride-filled microbubbles. The diagnostic accuracy of baseline US, CD-US, and CE-US were calculated by using the endoscopic and histologic findings as reference standards and correlated with the CDAIs by using the Pearson linear correlation coefficient.

RESULTS

Forty-seven patients (20 men; 27 women; mean age +/- SD, 38 +/- 14 years) with a CDAI > 150 (n = 30) or < 150 (n = 17), were recruited. CE-US showed the highest performance, with 93.5% sensitivity, 93.7% specificity, and 93.6% overall accuracy. CE-US revealed 3 bowel wall perfusion patterns after microbubble injection: submucosal enhancement and inward and outward transparietal enhancement. The linear correlation coefficient for CE-US versus CDAI was 0.74 (P < .0001); for baseline US (assessing thickness, length, and multilayer appearance of the diseased bowel) versus the CDAI, the coefficients were 0.68 (P < .0001), 0.47 (P = .0009), and 0.60 (P < .0001), respectively; and for CD-US versus CDAI the coefficient was 0.73 (P < .0001).

CONCLUSIONS

CE-US has a high sensitivity and specificity in detecting inflammatory activity and a strong correlation with the CDAI.

Oral contrast-enhanced sonography for the diagnosis and grading of postsurgical recurrence of Crohn's disease

BACKGROUND

Postsurgical recurrence (PSR) is very common in patients with Crohn's disease (CD) and previous surgery. Endoscopy is crucial for the diagnosis of PSR, also showing high prognostic value. Bowel sonography (BS) with or without oral contrast enhancement (OCBS) is accurate for CD diagnosis but its role in PSR detection and grading is poorly investigated. The aim was to evaluate the diagnostic accuracy of BS and OCBS for PSR compared to the endoscopical Rutgeerts's grading system.

METHODS

We prospectively performed endoscopy, BS, and OCBS in 40 CD patients with previous bowel resection to provide evidence of possible PSR. Endoscopy, BS, and OCBS were executed 1 year after surgery, with PSR diagnosis and grading made in accordance with Rutgeerts. BS and OCBS were considered suggestive for PSR in the presence of bowel wall thickness (BWT) >3 mm. OCBS was performed after ingestion of 750 mL of polyethylene glycol (PEG). Also, a receiver operating characteristic (ROC) curve was constructed in order to define the best cutoff of BWT to discriminate mild from severe PSR (grade 0-2 versus 3-4 of Rutgeerts) for both BS and OCBS.

RESULTS

In all, 22 out of the 40 CD showed an endoscopic evidence of PSR (55%). A severe PSR was present in 14 patients (64%). Sensitivity, specificity, and positive and negative predictive values were 77%, 94%, 93%, and 80% for BS, and 82%, 94%, 93%, and 84% for OCBS. On the ROC curve a BWT >5 mm showed sensitivity, specificity, and positive and negative predictive values of 93%, 96%, 88%, and 97% for the diagnosis of severe PSR at BS, while a BWT >4 mm was the best cutoff differentiating the mild from the severe CD recurrence for OCBS, with a sensitivity, specificity, and positive and negative predictive values of 86%, 96%, 97%, and 79%, respectively.

CONCLUSIONS

Both BS and OCBS show good sensitivity and high specificity for the diagnosis of PSR in CD, with a BWT >5 mm for BS and BWT >4 mm for OCBS strongly indicative of severe endoscopic PSR. Accordingly, these techniques could replace endoscopy for the diagnosis and grading of PSR in many cases.

Non-invasive techniques for assessing postoperative recurrence in Crohn's disease

Postoperative recurrence after ileo-colonic resection is a feature of Crohn's Disease (CD), almost 73% of patients show endoscopic recurrence at 1 year and 90% at 3 years. After surgical resection for CD, symptoms may be related to the surgical resection itself. Moreover, the development of an early severe endoscopic recurrence within 1 year represents a risk factor for early clinical recurrence. On the basis of these observations, the early detection and assessment of asymptomatic endoscopic recurrence may allow a timely and appropriate treatment of CD patients after ileo-colonic resection. At this purpose, conventional colonoscopy with ileoscopy currently represents the gold standard for assessing CD recurrence, graded according to the Rutgeerts' score. Lesions compatible with CD recurrence can be also detected by conventional radiology, including small bowel follow through and enema, both associated with a high radiation exposure. Due to the ineluctable course of CD after resection, and to the need of a proper follow up for assessing CD recurrence, several alternative, non invasive techniques have been searched in order to assess the post-operative recurrence, including: faecal alpha 1-antitrypsin clearance, faecal calprotectin, 99Tc-HMPAO scintigraphy, virtual colonoscopy, ultrasonography and, more recently, wireless capsule endoscopy (WCE) and Small Intestine Contrast Ultrasonography (SICUS). Among these, current evidences suggest that in experienced hands, ultrasound examination by SICUS represents a non-invasive technique useful for assessing recurrence in CD patients under regular follow up after surgery. The same findings are suggested for WCE, although the impact risk related to the recurrence or to the surgical anastomosis itself limits the use of this non-invasive technique for assessing CD recurrence after surgery.

Management of postoperative Crohn's disease

Three-quarters of the patients with Crohn's disease (CD) require surgery involving a resection in the course of their disease. Even if all macroscopically involved bowel is removed, the disease usually recurs proximal to, and at, the anastomosis. This often leads to the recurrent need for treatment of active disease, complications, and reoperation. Ileocolonoscopy has an important place in the assessment of postoperative Crohn's recurrence. The limited available data regarding drug therapy in the postoperative setting suggest that optimal management should include identification of high-risk patients earlier and more widespread use of immunosuppressive therapy than was previously recommended, and colonoscopic monitoring. Such strategies to prevent recurrence then need to be prospectively evaluated. This article examines the evidence for medical prophylaxis of postoperative CD, and proposes a treatment strategy based on current evidence.

Accuracy of endoscopic ultrasound for restaging rectal cancer following neoadjuvant chemoradiation therapy

OBJECTIVES

Endoscopic ultrasound (EUS) provides important information in the initial staging of patients with rectal cancer. Preoperative combined modality chemotherapy and radiation (neoadjuvant therapy) for patients with locally advanced rectal cancer may reduce local recurrence and improve survival. The accuracy of EUS restaging of rectal cancer after chemoradiation has not been extensively studied and its usefulness is unclear. The aim of this study was to verify the accuracy of EUS in staging rectal cancer after neoadjuvant chemoradiation in a large cohort of patients.

METHODS

EUS staging was performed before and after concurrent 5-fluorouracil and hyperfractionated radiotherapy in 82 patients with recently diagnosed locally advanced rectal cancer. All patients underwent subsequent surgical resection and complete pathologic staging.

RESULTS

After chemoradiation, 16 patients (20%) had no residual disease at pathologic staging. (T0N0). However, EUS correctly predicted complete response to chemoradiation in only 10 of 16 patients (63%). Overall accuracy of EUS post chemoradiation for pathologic T-stage was only 48%. Fourteen percent were understaged and 38% overstaged. EUS accuracy for N-stage was 77%. The T-category was correctly staged before surgery in 23 of the 56 responders (41%) and in 16 of 24 nonresponders (67%). EUS was unable to accurately distinguish postradiation changes from residual tumor.

CONCLUSION

EUS staging of rectal cancer after chemoradiation is inaccurate, especially in the group of patients with visual and EUS evidence of response. Its routine use for staging purposes after neoadjuvant chemoradiation for rectal cancer should be discouraged.