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

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.