Fasted and fed small bowel motility patterns at cine-MRI in chronic intestinal pseudo-obstruction

European Guideline on Chronic Nausea and Vomiting-A UEG and ESNM Consensus for Clinical Management

INTRODUCTION

Chronic nausea and vomiting are symptoms of a wide range of gastrointestinal and non-gastrointestinal conditions. Diagnosis can be challenging and requires a systematic and well-structured approach. If the initial investigation for structural, toxic and metabolic disorders is negative, digestive motility and gut-brain interaction disorders should be assessed. United European Gastroenterology (UEG) and the European Society for Neurogastroenterology and Motility (ESNM) identified the need for an updated, evidence-based clinical guideline for the management of chronic nausea and vomiting.

METHODS

A multidisciplinary team of experts in the field, including European specialists and national societies, participated in the development of the guideline. Relevant questions were addressed through a literature review and statements were developed and voted on according to a Delphi process.

RESULTS

Ninety-eight statements were identified and voted following the Delphi process. Overall agreement was high, although the grade of scientific evidence was low in many areas. Disagreement was more evident for some pharmacological treatment options. A diagnostic algorithm was developed, focussing on the differentiating features between gastrointestinal motility and gut-brain interaction disorders with predominant nausea and vomiting.

CONCLUSION

These guidelines provide an evidence-based framework for the evaluation and treatment of patients with chronic nausea and vomiting.

Quantitative Analysis of Small Intestinal Motility in 3D Cine-MRI Using Centerline-Aware Motion Estimation

BACKGROUND

Currently available tools for noninvasive motility quantification of the small intestine are limited to dynamic 2D MRI scans, which are limited in their ability to differentiate between types of intestinal motility.

PURPOSE

To develop a method for quantification and characterization of small intestinal motility in 3D, capable of differentiating motile, non-motile and peristaltic motion patterns.

STUDY TYPE

Prospective.

SUBJECTS

Fourteen healthy volunteers (127 small intestinal segments) and 10 patients with Crohn's disease (87 small intestinal segments).

FIELD STRENGTH/SEQUENCE

3.0 T, 3D balanced fast field echo sequence, 1 volume per second.

ASSESSMENT

Using deformable image registration between subsequent volumes, the local velocity within the intestinal lumen was quantified. Average velocity and average absolute velocity along intestinal segments were used with linear classifiers to differentiate motile from non-motile intestines, as well as erratic motility from peristalsis. The mean absolute velocity of small intestinal content was compared between healthy volunteers and Crohn's disease patients, and the discriminative power of the proposed motility metrics for detecting motility and peristalsis was determined. The consensus of two observers was used as referenced standard.

STATISTICAL TESTS

Student's t-test to assess differences between groups; area under the receiver operating characteristic curve (AUC) to assess discriminative ability. P < 0.001 was considered significant.

RESULTS

A significant difference in the absolute velocity of intestinal content between Crohn's patients and healthy volunteers was observed (median [IQR] 1.06 [0.61, 1.56] mm/s vs. 1.84 [1.37, 2.43] mm/s), which was consistent with manual reference annotations of motile activity. The proposed method had a strong discriminative performance for detecting non-motile intestines (AUC 0.97) and discernible peristalsis (AUC 0.81).

DATA CONCLUSION

Analysis of 3D cine-MRI using centerline-aware motion estimation has the potential to allow noninvasive characterization of small intestinal motility and peristaltic motion in 3D.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Chronic intestinal pseudo-obstruction in adults: A practical guide to identify patient subgroups that are suitable for more specific treatments

Chronic intestinal pseudo-obstruction is a rare and heterogeneous syndrome characterized by recurrent symptoms of intestinal obstruction with radiological features of dilated small or large intestine with air/fluid levels in the absence of any mechanical occlusive lesion. Several diseases may be associated with chronic intestinal pseudo-obstruction and in these cases, the prognosis and treatment are related to the underlying disease. Also, in its "primary or idiopathic" form, two subgroups of patients should be determined as they require a more specific therapeutic approach: patients whose chronic intestinal pseudo-obstruction is due to sporadic autoimmune/inflammatory mechanisms and patients whose neuromuscular changes are genetically determined. In a context of a widely heterogeneous adult population presenting chronic intestinal pseudo-obstruction, this review aims to summarize a practical diagnostic workup for identifying definite subgroups of patients who might benefit from more specific treatments, based on the etiology of their underlying condition.

Technical Feasibility of Quantitative Measurement of Various Degrees of Small Bowel Motility Using Cine Magnetic Resonance Imaging

OBJECTIVE

Cine magnetic resonance imaging (MRI) has emerged as a noninvasive method to quantitatively assess bowel motility. However, its accuracy in measuring various degrees of small bowel motility has not been extensively evaluated. We aimed to draw a quantitative small bowel motility score from cine MRI and evaluate its performance in a population with varying degrees of small bowel motility.

MATERIALS AND METHODS

A total of 174 participants (28.5 ± 7.6 years; 135 males) underwent a 22-second-long cine MRI sequence (2-dimensional balanced turbo-field echo; 0.5 seconds per image) approximately 5 minutes after being intravenously administered 10 mg of scopolamine-N-butyl bromide to deliberately create diverse degrees of small bowel motility. In a manually segmented area of the small bowel, motility was automatically quantified using a nonrigid registration and calculated as a quantitative motility score. The mean value (MV) of motility grades visually assessed by two radiologists was used as a reference standard. The quantitative motility score's correlation (Spearman's ρ) with the reference standard and performance (area under the receiver operating characteristics curve [AUROC], sensitivity, and specificity) for diagnosing adynamic small bowel (MV of 1) were evaluated.

RESULTS

For the MV of the quantitative motility scores at grades 1, 1.5, 2, 2.5, and 3, the mean ± standard deviation values were 0.019 ± 0.003, 0.027 ± 0.010, 0.033 ± 0.008, 0.032 ± 0.009, and 0.043 ± 0.013, respectively. There was a significant positive correlation between the quantitative motility score and the MV (ρ = 0.531, P < 0.001). The AUROC value for diagnosing a MV of 1 (i.e., adynamic small bowel) was 0.953 (95% confidence interval, 0.923-0.984). Moreover, the optimal cutoff for the quantitative motility score was 0.024, with a sensitivity of 100% (15/15) and specificity of 89.9% (143/159).

CONCLUSION

The quantitative motility score calculated from a cine MRI enables diagnosis of an adynamic small bowel, and potentially discerns various degrees of bowel motility.

Cine magnetic resonance urography and Whitaker test: dynamic visualized and quantified tools in ileal ureter replacement

Background

To assess the feasibility and usefulness of cine magnetic resonance urography (MRU) and Whitaker test as postoperative evaluation tools of ileal ureter replacement.

Methods

We retrospectively collected the medical records of 42 patients who underwent ileal ureter replacement between August 2015 and August 2020. The morphology, luminal diameter, amplitude, contraction ratio, peristaltic frequency, ureteral jets and peristalsis efficiency were recorded in cine MRU. Under different perfusion loads, image and pressure changes of the reconstructed upper urinary tract were recorded in the Whitaker test. Patients were categorized into normal pressure and elevated pressure groups.

Results

A total of 42 patients underwent cine MRU, and 20 of them finished the Whitaker test successfully. The mean amplitude was 9.29±3.51 mm, and the contraction ratio was 0.607 (0.247–0.790). The median peristaltic efficiency was 0.75 (0.29–1). Three patients presented an unusual rise in renal pelvis pressure, which was 54, 26, 57 cmH₂O respectively. The amplitude of the ileal graft in the elevated pressure group was larger (13.80±5.73 vs. 8.09±3.38 mm, P=0.024), the contraction ratio was higher [0.68 (0.59–0.79) vs. 0.59 (0.25–0.79), P=0.028], the peristaltic frequency was more active [7 (6–8) vs. 4 (3–8), P=0.025], but the peristaltic efficiency was lower [0.50 (0.29–0.50) vs. 0.75 (0.33–1), P=0.029] compared to the normal pressure group. There were no significant differences in the ureteral jets [3 (2–4) vs. 3 (1–7), P=0.840), creatinine (97.3±7.3 vs. 103.2±30.7 µmol/L, P=0.753), and estimated glomerular filtration rate (eGFR) (76.4±14.1 vs. 68.5±28.7 mL/min·1.73 m², P=0.663).

Conclusions

Cine MRU provides morphological and peristaltic motility of the ileal graft, cine MRU after ileal ureter replacement was recommended as a routine examination. The Whitaker test represents a complementary investigation to evaluate pressure changes to reveal the ability to transport urine, and it can be used as a supplementary examination to clarify equivocal cases.

Pediatric Intestinal Pseudo-Obstruction: Progress and Challenges

BACKGROUND

Chronic intestinal pseudo-obstruction is a rare disorder and represents the most severe form of gastrointestinal dysmotility with significant morbidity and mortality. Emerging research shows considerable differences between the adult and pediatric population with intestinal pseudo-obstruction and the term Pediatric Intestinal Pseudo-Obstruction (PIPO) was recently proposed.

PURPOSE

The aim of this article is to provide pediatric gastroenterologists and pediatricians with an up to date review of the etiology and underlining pathophysiology, clinical features, diagnostic and management approaches currently available for PIPO and to discuss future perspectives for the diagnosis and management of this rare disease.

Recent Advances in the Management of Severe Gastrointestinal Dysmotility

Severe gastrointestinal motility disorders with small bowel involvement continue to pose a major clinical challenge to clinicians, particularly because of the limitations of diagnostic tests and the lack of efficacious treatment options. In this article, we review current understanding and the utility of diagnostic modalities and therapeutic approaches, and describe how their limitations may potentially exacerbate prolonged suffering with debilitating symptoms, diagnostic delays, the risk of iatrogenic harm and increased healthcare utilisation in this group of patients. Moreover, observations from intestinal failure units worldwide suggest that this problem could be set to increase in the future, with reported trends of increasing numbers of patients presenting with nutritional consequences. Unfortunately, until recently, there has been a lack of consensus recommendations and guidance to support clinicians with their management approach. The aim of this narrative review is to summarise recent developments in this field following publication of an international census of experts, and subsequent clinical guidelines, which have emphasized the importance of holistic, multidisciplinary care. This is particularly important in achieving good clinical outcomes and ensuring the appropriate use of artificial nutritional support, in order to prevent iatrogenic harm. We discuss how these recent developments may impact clinical practice by supporting the development of specialised clinical services to deliver optimal care, and highlight areas where further research is needed.