Studies Support Transmural Healing as a Relevant Treatment Target in Crohn Disease

Investigators performed a systematic review to examine the varying definitions of transmural healing and assess its impact on CD-related outcomes.

Transmural healing may represent an important treatment target in Crohn disease (CD), when assessed based on bowel wall thickness using different imaging modalities at certain time points during disease management, according to research findings published in The Lancet Gastroenterology & Hepatology.

A small team of investigators performed a systematic review to examine the varying definitions of transmural healing and assess its impact on CD-related outcomes. A total of 17 relevant studies were identified and included in the review. Across these studies, researchers reported transmural healing rates ranging between 14.0% and 42.4%.

Up to 7 studies assessed transmural healing through bowel sonography. Magnetic resonance enterography was used to assess transmural healing in 10 studies, while computed tomography (CT) enterography was used in 3 studies. Another 3 studies combined magnetic resonance enterography and bowel sonography or CT enterography and magnetic resonance enterography.

According to the review authors, transmural healing may be assessed as 12 weeks using bowel sonography and at 26 weeks using magnetic resonance enterography or CT enterography.

Transmural healing was defined in most studies as a bowel wall thickness ≤3 mm. The majority of studies relied on this measurement of bowel wall thickness as the most frequent cutoff.  The use of doppler ultrasound to assess vascularization as well as the absence of complications or contrast enhancement were also used to define transmural healing.

In 9 studies, the risk for surgery significantly decreased in patients with CD who achieved transmural healing compared with those who did not (P <.05). Additionally, transmural healing was significantly associated with clinical remission in 3 studies. Transmural healing was also associated with decreased rates of hospitalization in 4 studies.

The investigators noted that it remains a challenge to demonstrate the superiority of transmural healing over mucosal healing, as there is currently a lack of evidence that the latter can change the natural course of CD.

According to the researchers, “Future prospective trials should be done to confirm the usefulness of these promising endpoints and to validate the definition of transmural healing.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Geyl S, Guillo L, Laurent V, D’Amico F, Danese S, Peyrin-Biroulet L. Transmural healing as a therapeutic goal in Crohn’s disease: a systematic review. Lancet Gastroenterol Hepatol. Published online June 3, 2021. doi:10.1016/S2468-1253(21)00096-0