DOP083 «Sonorescue»-treatment response in acute severe Ulcerative Colitis measured with ultrasound
Authors: Nylund K , Gjengstø A J , von Volkmann H L , Aziz A , Riise G N , Gilja O H 
Published: January 2025

Abstract

Background
First line medical treatment in acute severe ulcerative colitis (ASUC) is intravenous corticosteroids. Patients with insufficient response receives rescue treatment. The decision is made by the treating physician and is based on disease severity and improvement in stool frequency, rectal bleeding, biochemical parameters, and general well-being. Gastrointestinal ultrasound (GIUS) can be used to find the degree of inflammation in ulcerative colitis, but can it be used to detect the lack of treatment response in ASUC?

Methods
Patients with ASUC were included from June 2020 to Nov 2024 at two hospitals in Bergen, Norway. They were examined with GIUS prior to treatment with iv corticosteroids and after 2-3 days of treatment. Patients with a normal GIUS, endoscopic MAYO&lt;2 or isolated proctitis were excluded. Bowel wall thickness, bowel wall vessel density with colour Doppler, loss of haustration and fatty tissue reaction was registered for every segment of the colon as well as an activity score based on these parameters1. The two main outcomes of the study were the clinical decision to give rescue with infliximab and Lindgren’s criteria for the risk of colectomy2.

Results
In total 33/64 patients received rescue treatment. In the sigmoid colon the wall was 4.3±1,3 mm in patients receiving rescue treatment and 2.5±1mm in the others (p&lt;0.001). There was also a significant difference in vessel density, haustrations, and fatty tissue reaction. Furthermore, there were significant differences for wall thickness in all the other colon segments including the sum of these measurements. The full score based on all parameters was 15.2±5,2 vs 8.3±5,3 (p&lt;0.001). The areas under the receiver operating curve (AUROC) for wall thickness in the sigmoid colon, total bowel wall thickness and the activity score were 0.87 (0.79-0.96), 0.84 (0.75-0.94) and 0.84 (0.74-0.94), respectively. According to Lindgren’s Criteria 23/64 had a high risk for colectomy. AUROCs for the same parameters were 0.86(0.75-0.96), 0.88(0.80-0.97) and 0.85 (0.76-0.94), respectively. If a low risk of colectomy is required a total bowel wall thickness ≥ 9mm at day 2-3 predicts the risk of colectomy with 100% sensitivity and 50% specificity. For the single measurement in the sigmoid colon and a corresponding sensitivity of 96% (cut off 2.4 mm) the specificity will wall fall to 32.5%.

Conclusion
GIUS can be used to detect insufficient treatment response in ASUC already after 2-3 days of intravenous corticosteroids which confirms previous findings3. A single measurement in the sigmoid colon could be sufficient, but the combined sum of bowel wall thickness in all colon segments could be better for selecting patients that should get rescue treatment.

References
1.Bots S, Nylund K, Lowenberg M, Gecse K, D'Haens G. Intestinal Ultrasound to Assess Disease Activity in Ulcerative Colitis: Development of a novel UC-Ultrasound Index. J Crohns Colitis. Aug 2 2021;15(8):1264-1271. doi:10.1093/ecco-jcc/jjab002
2.Lindgren SC, Flood LM, Kilander AF, Lofberg R, Persson TB, Sjodahl RI. Early predictors of glucocorticosteroid treatment failure in severe and moderately severe attacks of ulcerative colitis. Eur J Gastroenterol Hepatol. Oct 1998;10(10):831-5. doi:10.1097/00042737-199810000-00003
3.Ilvemark J, Wilkens R, Thielsen P, et al. Early Intestinal Ultrasound Predicts Intravenous Corticosteroid Response in Hospitalised Patients With Severe Ulcerative Colitis. J Crohns Colitis. Nov 23 2022;16(11):1725-1734. doi:10.1093/ecco-jcc/jjac083