Prospective Multicenter Randomized Comparative Study of the Treatment of de Novo Stenosis in Chron's Disease.

Stenosis is one of the most frequent complications in patients with Crohn's disease (CD), causing greater morbidity and increasing the probability of repeated surgery and short bowel syndrome (1-3). Endoscopic balloon dilation (EBD) is clearly the treatment of choice for short stenoses located at the anastomosis of previous surgeries (4-6). However, there is no scientific evidence for determining the most appropriate treatment for de novo stenosis less than 10 cm in length (surgical versus endoscopic treatment), both in terms of efficacy and complications. Neither has it been established which of these two approaches has a greater impact on the quality of life of patients and on costs.

In many cases, a surgical approach allows for the removal of the entire inflamed intestine. However, the percentage of post-surgical recurrence per year after surgery is 80-85% (7), decreasing to 40% in patients who begin preventive immunosuppressive treatment in the immediate post-surgery period (8). This means that more than 40% of patients will require combined immunosuppression to keep CD under control one year after surgery. Endoscopic treatment does not remove the affected intestine. However, it has a long-term therapeutic efficacy of 50-60% with a very low percentage of complications (4-6%). A large number of studies have shown that patients' quality of life improves when CD is properly controlled, either through medical or surgical treatment (9). However, there are no studies evaluating the quality of life of patients after endoscopic treatment. Neither are there comparative studies of the costs of the two procedures. However, a recent study comparing the cost of 38 endoscopic procedures with their surgical equivalent suggested that, in most cases, the cost of endoscopic treatment is four times lower (10). The European Crohn's and Colitis Organization (ECCO) guidelines on the management of de novo stenosis in patients with CD recommend surgery as the first option, based on expert opinion (Level of Evidence 4), although there are no studies comparing the two treatment modalities (11,12). A Spanish multicenter study coordinated by researchers involved in the present project (Andujar X, et al)(13), which included the largest published series of endoscopic treatment with dilation in patients with CD to date, shows that therapeutic success with EBD in de novo stenoses is achieved in a large percentage of cases, with results similar to those obtained in post-surgical stenoses (73% vs 84%). In addition, CD stenoses can be treated effectively with self-expanding metal stents (SEMS), and it has been suggested that these may be particularly indicated in patients who are refractory to balloon dilation, including both de novo and anastomotic stenosis patients (14-17). Therefore, in order to compare the efficacy of these two endoscopic treatments, the PROTDILAT study (IP: C Loras. Project FIS nº Pl13/01226 and Clinical Trials. Gov nº NCT02395354) was designed, and is currently in the final manuscript writing phase (100 patients included). The final results (Andújar X, UEGW 2019)(18) confirm that both procedures are effective and safe in the treatment of both post-surgical and de novo stenosis, while showing the therapeutic superiority of EBD over SEMS when the results are evaluated globally (80.5 vs 51.3 %; primary end point). However, this difference is not observed in the subanalysis of patients with stenosis ≥4 cm (LBD: 66.7% vs PMA: 63.6%) but with a significantly lower cost in EDB treatment (EDB 1,212.41 euros vs PMA 3,615.07 euros). Therefore, SEMS may have a role to play in longer stenosis in which EBD has proven to be less efficacious. This work has been conceived as an exploratory proof of concept study, given that there are currently no studies comparing surgical and endoscopic approaches and it is therefore difficult to calculate the adequate sample size.