Intestinal ultrasound in Crohn’s disease: A systematic review of its role in diagnosis, monitoring, and treatment response

Table 9 Summary of studies evaluating transmural healing in Crohn’s disease with intestinal ultrasound

Ref.	Study type	Number of patients	Follow-up	Definition of healing	Outcomes of TH or TR
Vaughan et al[127], 2022	Retrospective	202 CD	19 months	Normal BWT, no CDS, no inflammatory fat, no loss of wall stratification	TH associated with steroid-free and treatment escalation-free survival but not hospitalization or surgery
Helwig et al[123], 2022	Post hoc analysis (TRUST)	351 CD and UC	52 weeks	Simplified TH: Normal BWT, no CDS; Extended TH: Normal BWT + 2 of 3 (normal CDS, no loss of stratification, no inflammatory fat); Complete TH: Normal BWT + all 3	TH at week 12 associated with clinical remission and no escalation of therapy at 52 weeks
Ma et al[128], 2021	Prospective	77 CD	12 months	Normal BWT, no hypervascularization, no inflammatory fat, no loss of stratification	TH predicted steroid-free clinical remission, lower need for drug escalation, and hospitalization; TH showed better predictive value than mucosal healing
Castiglione et al[124], 2013	Observational longitudinal	133 CD	2 years	TH: Normalization of BWT ≤ 3 mm on bowel sonography	25% achieved TH on anti-TNF, correlating with mucosal healing; TH as an indicator of deeper remission and improved outcomes
Castiglione et al[125], 2022	Observational longitudinal	118 CD	2 years	TH: Normal BWT ≤ 3 mm; correlation with fecal calprotectin and CRP	TH achieved in 32.2%, associated with improved long-term outcomes, including relapse reduction
Ferrer et al[122], 2021	Retrospective	277 CD	24 months	Parietal healing: Normal BWT, no hyperemia, and absence of complications	PH associated with better outcomes, including relapse-free survival and reduced disease activity

CD: Crohn’s disease; TH: Transmural healing; TR: Transmural response; BWT: Bowel wall thickness, CDS: Colour Doppler signal; TNF: Tumor necrosis factor; CRP: C-reactive protein.