Digestive Tract Damage: A Predictor of Early Surgical Intervention in Patients With Newly Diagnosed Crohn’s Disease
In everyday clinical practice, most patients newly diagnosed with Crohn’s disease undergo medical management. In some patients (20%–30%), early medical treatment will fail, and those patients will require surgical intervention within a year.1,2 Thus, the question arises: in the era of personalized medicine, can we predict in which patients medical management will fail within 1 year of diagnosis? In these cases, early surgical intervention could avoid unnecessary use of medications as first-line therapy.
To date, several laboratory, molecular, and clinical factors have been identified as risk factors for the need for surgery.2 These factors have been identified in different studies, but have never been used in a combined fashion to actually provide a predictive model that will reliably determine whether surgical intervention will be needed in the near future. Furthermore, the course of Crohn’s disease is very heterogeneous and difficult to foresee, requiring consideration of a plethora of factors to attempt to predict it. Patients of young age, with early age at diagnosis, with perianal disease, with significant weight loss, persistent need for use of steroids, with penetrating or stricturing disease, high C-reactive protein levels, NOD2 mutated among many other factors, are considered high risk for having surgery.3 Although, the treatment of Crohn’s disease is focused on mucosal healing, there is not much research into the extent and severity of the full-thickness digestive tract tissue damage as a risk factor for surgery.
In this issue of Disease of the Colon & Rectum, Liu et al have conducted a study that investigates the use of the Lémann index at the time of diagnosis of Crohn’s disease as a score to predict the risk for abdominal surgery in the first year.4 The Lémann score was developed by a European group (International Program to develop New Indexes in Crohn’s disease group) that was formed in 2007.5 The group developed an instrument that can measure the cumulative bowel damage in patients with Crohn’s disease. The score takes into account the location of the tissue damage, the extent, and the severity. The calculation of the score is performed by using imaging (magnetic reasoning enterography, computed tomography enterography, ultrasound) and endoscopic assessment to overall appreciate the extent of tissue damage.6
In their study, Liu et al use a strictly selected cohort of patients newly diagnosed with Crohn’s disease that were followed closely for over a year to determine the need for surgical intervention. The study calculated a score cutoff (Lémann score: >3.7) that provides >80% specificity and sensitivity for predicting the need for early surgical intervention. Although the positive predictive value of the test was 61%, the negative predictive value was 94%. Essentially, a low Lémann score eliminates the probability that the patient will need surgical intervention within a year from diagnosis. Furthermore, in an attempt to create a predictive model, a multivariate analysis predicting the likelihood for surgery was performed. The authors, in addition to the Lémann score, used known risk factors for surgery in Crohn’s disease (behavior of disease, steroids, immunomodulators, biologic medication, Harvey Bradshaw Index) in this multivariate analysis. The Lémann score remained an independent predictor for early surgical intervention.