Early improvement in bowel wall thickness on transperineal ultrasonography predicts treatment success in active...

Bowel ultrasonography is a non-invasive imaging tool that can repeatedly monitor ulcerative colitis (UC) activity.

This study aimed to determine whether early transabdominal or transperineal ultrasonography changes can predict subsequent clinical response to induction therapy in patients with UC.

This single-centre prospective study explored ultrasonographic predictors for clinical remission (patient-reported outcome-2 ≤ 1 with no rectal bleeding subscore) at week 8 in patients with active UC who underwent induction therapy, in comparison with faecal calprotectin and C-reactive protein (measured at baseline, week 1 and week 8). Predictive factors were assessed using multivariable regression models and receiver-operating-characteristic curve analysis.

A total of 100 patients were analysed, of which 54 achieved remission at week 8. Baseline biomarker and ultrasonographic-parameter values were not predictive of remission. Contrastingly, change from baseline to week 1 in rectal bowel wall thickness measured using transperineal ultrasonography was an independent predictor of remission by week 8 (adjusted odds ratio is associated with a 1-mm decrease: 1.90 [95% confidence interval, 1.22-2.95]). In a subgroup analysis of the patients who did not achieve remission in 1 week, the predictive value of change in rectal bowel wall thickness remained high (AUC = 0.77 [95% confidence interval, 0.61-0.88]).

Improvement in rectal bowel wall thickness measured using transperineal ultrasonography at week 1 predicts treatment success and potentially facilitates decision making during the early course of induction therapy in UC.