P355 Motility in small bowel strictures in Crohn’s Disease measured with cine-MRI

Abstract

Abstract Background Strictures develop in over half of Crohn’s Disease (CD) patients and can lead to complaints of bowel obstruction, requiring treatment. A study showed that strictures and pre-stricture small bowel (SB) have lower motility measured with cine-MRI, compared to normal bowel in CD. However, stricture motility has not been correlated with disease duration or Harvey Bradshaw Index (HBI). Investigating this correlation can provide insight in the physiologic behavior of a stricture in relation to the extent of bowel damage (disease duration) and clinical complaints (HBI). This could possibly support the clinician in treatment decisions. Our aim is to investigate correlations between stricture motility measured with cine-MRI and disease duration and HBI, respectively. Methods At a tertiary center CD patients (≥18yrs) with SB strictures were included. Patients fasted 4 hours, after which they drank 1600 mL (2.5%-mannitol-solution) in 60 minutes prior to 3T MRI. All underwent coronal dynamic 2D bFFE scans of the most stenotic SB and the pre-stenotic dilation if present, during a 20-second expiration breath-hold. Bowel motility was assessed with a validated displacement mapping technique (GIQuant, Entrolytics, Motilent, UK). Strictures (wall thickening >3mm and ≥50% luminal reduction) and pre-stenotic dilations (luminal diameter >3cm) were delineated on a reference image and motility was quantified on a motility map within these regions of interest (ROI), producing a single, numerical motility score (Arbitrary Units=AU). Stricture and pre-stenotic dilation motility scores are presented in medians [IQR]. Correlation was tested between stricture motility, disease duration and HBI by means of spearman’s rank correlation test. Results Twenty-two patients (55% male, age 37yrs [IQR 25-55], disease duration 7yrs[IQR 4-12]) were included. SB stricture motility was 57AU[IQR 48-71]. Pre-stenotic dilation motility (n=6) was 131AU[IQR 88-340]. Disease duration and stricture motility showed no correlation(r=0.2, p=0.4). HBI and stricture motility were inversely correlated(r=-0.6, p<0.01). Conclusion We found an inverse correlation between SB stricture motility and HBI. No correlation was found between SB stricture motility and disease duration. The inverse correlation between HBI and stricture motility suggests that lower motility is associated with poorer clinical condition. This finding can possibly lead to earlier endoscopic or surgical intervention, since it indicates lower motility is associated with poorer clinical condition. Interestingly, we also measured higher pre-stenotic dilation motility compared to stricture motility, presumably a physiological response of the pre-stenotic dilation to the distal stricture and ongoing proximal peristalsis.