P158. Real-time strain elastography accurately differentiates between inflammatory and fibrotic strictures in Crohn's disease
C. Bezzio1, M. Monteleone1, A. Friedman2, F. Furfaro1, P. Fociani3, G.M. Sampietro4, S. Ardizzone1, R. De Franchis1, G. Maconi1, 1Gastrointestinal Unit – L. Sacco university Hospital, Clinical Sciences, Milan, Italy, 2The Alfred Hospital and Monash University, Department of Gastroenterology, Melbourne, Australia, 3Luigi Sacco University Hospital, Pathology unit, Milan, Italy, 4Luigi Sacco University Hospital, Division of General Surgery II, Milan, Italy
Differentiation between inflammation-predominant and fibrosis-predominant strictures is crucial in determining the optimal therapy for patients with stricturing Crohn's disease (CD). To date, there are no reliable, non-invasive imaging techniques that can differentiate between inflammation and fibrosis in CD. Strain elastography (SE) via transcutaneous ultrasound is a promising, non-invasive technique for assessing strictures. The purpose of this study is to evaluate the accuracy of real-time SE for the characterisation of CD strictures in comparison to histopathological assessment of surgical resection specimens.
Preoperative ultrasound with SE was performed in 28 consecutive patients with known strictures of the terminal ileum undergoing elective resection. Longitudinal and transverse SE scanning of affected segments was performed to estimate tissue elasticity (strain ratio, SR) using two different machines (Hitachi Logos HiVision C and Esaote MyLab 70 Gold). This technique was performed preoperatively by transabdominal scan the day before surgery, and subsequently ex vivo on the resected stricture. A qualitative histopathological assessment of inflammation and fibrosis within the strictures was also performed by an experienced pathologist who was blinded to the SE results. Other ultrasound measurements, such as wall thickness, transmural complications and the number of strictures were also taken before surgery.
Both machines had no significant difference in SR values for transverse and longitudinal SE scans. Wall elasticity in each stricture detected in vivo did not differ significantly from that observed ex vivo. On ex vivo evaluation, the SR of the strictures was significantly lower than that of the normal wall (0.82±0.07 vs 1.77±0.17, p = 0.012). The ex vivo transverse measurements showed that the SR of fibrotic strictures were significantly lower than that of inflammatory strictures (0.64±0.06 vs 0.91±0.08, p = 0.046).
SE can differentiate inflammatory from fibrotic strictures in patients with CD. SE represents a novel technology with potential to become a new, objective, non-invasive technique to assess intestinal fibrosis that can guide patient management decisions. Further large scale studies are warranted.