TRUST&UCUC · Imaging and monitoring
Intestinal ultrasound for monitoring therapeutic response in patients with ulcerative colitis: results from the TRUST&UC study
Maaser C, et al.
Gut 2020 · PMID 31862811 (PubMed, opens in a new tab) · doi 10.1136/gutjnl-2019-319451 (full paper, opens in a new tab)
| Week (0 = at flare) | 0 | 2 | 6 | 12 |
|---|---|---|---|---|
| Sigmoid colon | 89.3% | 38.6% | 35.4% | 32.0% |
| Descending colon | 83.0% | 42.9% | 43.4% | 37.6% |
Week 2 was an unscheduled visit with fewer patients scanned, so the early drop is suggestive rather than definitive; it supports an early rescan.
Source: Maaser 2020, abstract. Thickening cut-offs (sigmoid above 4.0 mm, descending colon above 3.0 mm) are from the full text (PMC7456734), Methods.
Structured abstract
BackgroundIntestinal ultrasound was used mainly in Crohn's disease; its value for monitoring ulcerative colitis in routine practice had not been evaluated prospectively.
MethodsProspective, observational, multicentre study (42 German IBD centres, including practices and hospitals, 2015–2018); not randomised. 253 patients. Primary endpoint: Normalisation of bowel wall thickness at week 12 in relation to clinical response (fall in SCCAI of 3 or more points).
ResultsPrimary result. Clinical response at week 12 was more frequent with normalised bowel wall thickness: sigmoid colon 90.5% (95/105) vs 68.5% (50/73); descending colon 96.4% (80/83) vs 68.4% (65/95); P<0.001 for each.
Take-homeIntestinal ultrasound shows bowel wall thickening in most UC flares and tracks response within 2 weeks, so it is a practical point-of-care tool for monitoring UC treatment.
| Patients | 253 |
|---|---|
| Population | Adults with proctosigmoiditis, left-sided colitis or pancolitis in clinical relapse (Simple Clinical Colitis Activity Index 5 or more), treated at the physician's discretion. 224 with increased bowel wall thickness at baseline formed the analysis population; 178 completed week 12. |
| Comparison | No comparison arm: ultrasound at baseline and weeks 2, 6 and 12, correlated with clinical response and faecal calprotectin. |
| Published | Maaser C, et al. Gut 2020;69:1629–36. |
Key points
- 88.5% (224/253) had increased bowel wall thickness in the sigmoid or descending colon at the time of flare.
- Response was fast: increased wall thickness in the sigmoid fell from 89.3% at baseline to 38.6% at week 2 (35.4% at week 6, 32.0% at week 12); descending colon 83.0% to 42.9% (43.4%, 37.6%); P<0.001.
- Calprotectin normalised (below 250 µg/g) more often when wall thickness normalised: sigmoid 48.9% vs 22.2% (P=0.023); descending 50.0% vs 25.0% (P=0.029).
- Thickness cut-offs used: sigmoid above 4.0 mm; descending, transverse and ascending colon above 3.0 mm.
Limitations
- Observational, with no endoscopic reference standard for most patients.
- Treatment varied and was chosen by the physician.
- Rectal disease is poorly seen with transabdominal ultrasound; isolated proctitis was not included.
- Conducted with AbbVie; company employees were co-authors.
Commentary
TRUST&UC is the largest multicentre study of intestinal ultrasound for monitoring ulcerative colitis, and it was done in routine practice rather than only in expert centres. It established that the sigmoid and descending colon thicken in most flares and that this improves within weeks of effective treatment.
How to use it: scan the sigmoid and descending colon at a flare to document a baseline, then rescan early (2 to 12 weeks) to judge response and decide on escalation. Use calprotectin or endoscopy when disease is limited to the rectum. For Crohn’s disease, see METRIC and the STARDUST ultrasound substudy.
Journal club
Design
Prospective, observational, multicentre study (42 German IBD centres, including practices and hospitals, 2015–2018); not randomised. 253 patients.
Primary result. Clinical response at week 12 was more frequent with normalised bowel wall thickness: sigmoid colon 90.5% (95/105) vs 68.5% (50/73); descending colon 96.4% (80/83) vs 68.4% (65/95); P<0.001 for each.
Validity and applicability
- Observational, with no endoscopic reference standard for most patients.
- Treatment varied and was chosen by the physician.
- Rectal disease is poorly seen with transabdominal ultrasound; isolated proctitis was not included.
- Conducted with AbbVie; company employees were co-authors.
Where it sits now
Intestinal ultrasound shows bowel wall thickening in most UC flares and tracks response within 2 weeks, so it is a practical point-of-care tool for monitoring UC treatment.
- METRIC (2018): Both MR enterography and intestinal ultrasound detect small bowel Crohn's disease with high sensitivity; MR enterography maps extent somewhat more accurately, while ultrasound is a valid first-line, point-of-care alternative.
- STARDUST (2022): With ustekinumab, an endoscopy-driven treat-to-target algorithm did not improve 48-week endoscopic response over clinically driven care; treat-to-target only helps if escalation has something to add.
Questions for discussion
- There was no endoscopic reference standard for most patients. What does normalised wall thickness actually tell you?
- How early would you rescan after starting a new therapy, and what change would make you escalate?