Different clinical outcomes in Crohn’s disease patients with esophagogastroduodenal, jejunal, and proximal ileal disease involvement: is L4 truly a single phenotype?

• Published in: Therapeutic advances in gastroenterology Vol. 11; p. 1756284818777938
• Main Authors: Mao, Ren, Tang, Rui-Han, Qiu, Yun, Chen, Bai-Li, Guo, Jing, Zhang, Sheng-Hong, Li, Xue-Hua, Feng, Rui, He, Yao, Li, Zi-Ping, Zeng, Zhi-Rong, Eliakim, Rami, Ben-Horin, Shomron, Chen, Min-Hu
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01-01-2018; SAGE Publishing
• Subjects: Original Research; Montreal classification; proximal ileum; Crohn’s disease; surgery
• ISSN: 1756-283X; 1756-2848; 1756-2848
• DOI: 10.1177/1756284818777938

Background:
The Montreal classification defines L4 Crohn’s disease (CD) as any disease location
proximal to the terminal ileum, which anatomically includes L4-esophagogastroduodenal
(EGD), L4-jejunal, and L4-proximal ileal involvement. L4-jejunal disease was established
to be associated with poor prognosis. However, the outcome of patients with L4-proximal
ileal disease or L4-EGD remains to be clarified. Our study aimed to investigate whether
the outcome differs among CD patients with L4-EGD, L4-jejunal, and L4-proximal ileal
disease.
Methods:
In our retrospective cohort study, 483 patients with confirmed CD were included. The
primary outcome was intestinal surgery. Demographic features and outcomes were compared
among L4-EGD, L4-jejunal, and L4-proximal ileal disease.
Results:
Thirty-nine (8.1%) patients had isolated L4 disease, whereas 146 patients had L4 as
well as concomitant L1, L2, or L3 disease. During a median follow up of 5.8 years, L4
patients were more likely to have intestinal surgeries compared to non-L4 patients (31%
versus 16%, p < 0.001). The percentage of
L4-jejunal patients who underwent surgery was higher than that of L4-proximal ileal (66%
versus 28%, p < 0.001), and both of these
subtypes of L4 were at higher risk for intestinal resection compared to L4-EGD patients
(66% and 28% versus 9%, respectively, p < 0.001 and
p < 0.05). On multi-variable analysis, L4-jejunal (HR 3.08; 95% CI
1.30–7.31) and L4-proximal ileal disease (HR 1.83; 95% CI 1.07–3.15) were independent
predictors for intestinal resection.
Conclusions:
L4 disease had worse prognosis compared to non-L4 disease. Within L4 disease, phenotype
of L4-jejunal and L4-proximal ileal disease indicated higher risk for intestinal
surgery. It might be justified to further characterize the L4 phenotype of the Montreal
classification into three specific subgroups including L4-EGD, L4-jejunal, and
L4-proximal ileal disease, similar to the Paris classification of pediatric
patients.