Letter: the impact of smoking on clinical outcomes after endoscopic dilatation in Crohn's disease



We read with interest the article by Gustavsson et al.[1] This retrospective study aimed to evaluate whether smoking at diagnosis may affect clinical outcomes after endoscopic dilatation of stricturing Crohn's disease (CD).

After index dilatation, 55 of 83 patients required a new intervention. Among current smokers, 31 of 32 patients (97%) underwent another intervention compared with 18 of 33 patients (55%) among never smokers (hazard ratio 2.50). After 5 years, the cumulative probability of new intervention was 0.81 in smokers compared to 0.52 in never smokers (difference 0.29). The authors concluded that smoking doubles the risk of recurrent stricture formation requiring a new intervention. This study provides important information regarding the deleterious effect of smoking on the outcomes after endoscopic dilatation.

We reported that smoking significantly increased the risk for recurrence after surgical resection for CD.[2] Smokers had an approximately twofold increased risk of recurrence compared with nonsmokers and the effect of smoking was dose-dependent. In the present study by Gustavsson et al.,[1] it is unclear whether the effect of smoking was dose-dependent. The impact of disease presentation at stricture sites is not evaluated: the number and length of stricture(s), or endoscopic appearance (fibrotic or inflamed). Furthermore, the influence of the skill and experience of the endoscopist is not assessed.

In this study,[1] only 16 of the 83 patients (19%) received azathioprine as maintenance therapy. No patient was treated with biological agents after endoscopic dilatation. Infliximab significantly reduces the risk of recurrence after resection for CD.[3, 4] Larger prospective studies are needed to rigorously evaluate the effects of smoking on clinical outcome after endoscopic dilatation. Furthermore, the effect of biological agents for prevention of recurrence after dilatation should be assessed.


Declaration of personal and funding interests: None.