Azatioprina y mesalazina en la prevención de la recurrencia posquirúrgica en la enfermedad de Crohn: estudio retrospectivo

Predicting, treating and preventing postoperative recurrence of Crohn's disease: the state of the field

The majority of patients diagnosed with Crohn's disease eventually require surgical intervention. Unfortunately, postsurgical remission tends to be short lived; a significant number of patients experience clinical relapse and many require additional operations. The pathogenesis of this postoperative recurrence is poorly understood and, currently, there are no reliable tools to predict when and in whom the disease will recur. Furthermore, the postoperative prophylaxis profiles of available Crohn's disease therapeutic agents such as 5-aminosalicylates, immunomodulators, steroids and probiotics have been disappointing. Recently, the combination of antibiotics and azathioprine in selected high-risk patients has demonstrated some potential for benefit. The goal of the present article is to provide a coherent summary of previous and new research to guide clinicians in managing the challenging and complex problem of postoperative Crohn's disease recurrence.

Interventions for prevention of post-operative recurrence of Crohn's disease

BACKGROUND

Recurrence of Crohn's disease is common after intestinal resection. A number of agents have been studied in controlled trials with the goal of reducing the risk of endoscopic or clinical recurrence of Crohn's disease following surgery.

OBJECTIVES

To undertake a systematic review of the use of medical therapies for the prevention of post-operative recurrence of Crohn's disease

SEARCH STRATEGY

MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify relevant studies. References from selected papers and abstracts from Digestive Disease Week were also searched.

SELECTION CRITERIA

Randomised controlled trials that compared medical therapy to placebo or other medical agents for the prevention of recurrence of intestinal Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors reviewed all abstracts containing search terms, and those meeting inclusion criteria were selected for full data abstraction. Dichotomous data were summarised using relative risk and 95% confidence intervals. A fixed-effects model was used, and sensitivity analysis performed.

MAIN RESULTS

Twenty-three studies were identified for inclusion. Probiotics were not superior to placebo for any outcome measured. The use of nitroimidazole antibiotics appeared to reduce the risk of clinical (RR 0.23; 95%CI 0.09 to 0.57, NNT=4) and endoscopic (RR 0.44; 95%CI 0.26 to 0.74, NNT = 4) recurrence relative to placebo. However, these agents were associated with higher risk of serious adverse events (RR 2.39, 95% CI 1.5 to 3.7). Mesalamine therapy was associated with a significantly reduced risk of clinical recurrence (RR 0.76; 95% CI 0.62 to 0.94, NNT = 12), and severe endoscopic recurrence (RR 0.50; 95% CI 0.29 to 0.84, NNT = 8) when compared to placebo. Azathioprine/6MP was also associated with a significantly reduced risk of clinical recurrence (RR 0.59; 95% CI 0.38 to 0.92, NNT = 7), and severe endoscopic recurrence (RR 0.64; 95% CI 0.44 to 0.92, NNT = 4), when compared to placebo. Neither agent had a higher risk than placebo of serious adverse events. When compared to azathioprine/6MP, mesalamine was associated with a higher risk of any endoscopic recurrence (RR 1.45, 95% CI 1.03 to 2.06), but a lower risk of serious adverse events (RR 0.51; 95% CI 0.30 to 0.89). There was no significant difference between mesalamine and azathioprine/6MP for any other outcome.

AUTHORS' CONCLUSIONS

There are insufficient randomised controlled trials of infliximab, budesonide, tenovil and interleukin-10 to draw conclusions. Nitro-imidazole antibiotics, mesalamine and immunosuppressive therapy with azathioprine/6-MP or infliximab all appear to be superior to placebo for the prevention of post-operative recurrence of Crohn's disease. The cost, toxicity and tolerability of these approaches require careful consideration to determine the optimal approach for post-operative prophylaxis.

Postoperative Crohn’s disease recurrence: A practical approach

Crohn's disease is a chronic inflammatory condition that may involve any segment of the gastrointestinal tract. Although several drugs have proven efficacy in inducing and maintaining disease in remission, resectional surgery remains as a cornerstone in the management of the disease, mainly for the treatment of its stenosing and penetrating complications. However, the occurrence of new mucosal (endoscopic) lesions in the neoterminal ileum early after surgery is almost constant, it is followed in the mid-term by clinical symptoms and, in a proportion of patients, repeated intestinal resections are required. Pathogenesis of postoperative recurrence (POR) is not fully understood, but luminal factors (commensal microbes, dietary antigens) seem to play an important role, and environmental and genetic factors may also have a relevant influence. Many studies tried to identify clinical predictors for POR with heterogeneous results, and only smoking has repeatedly been associated with a higher risk of POR. Ileocolonoscopy remains as the gold standard for the assessment of appearance and severity of POR, although the real usefulness of the available endoscopic score needs to be revisited and alternative techniques are emerging. Several drugs have been evaluated to prevent POR with limited success. Smoking cessation seems to be one of the more beneficial therapeutic measures. Aminosalicylates have only proved to be of marginal benefit, and they are only used in low-risk patients. Nitroimidazolic antibiotics, although efficient, are associated with a high rate of intolerance and might induce irreversible side effects when used for a long-term. Thiopurines are not widely used after ileocecal resection, maybe because some concerns in giving immunomodulators in asymptomatic patients still remain. In the era of biological agents and genetic testing, a well-established preventive strategy for POR is still lacking, and larger studies to identify good clinical, serological, and genetic predictors of early POR as well as more effective drugs (or drug combinations) are needed.

Impact of azathioprine on the prevention of postoperative Crohn's disease recurrence: results of a prospective, observational, long-term follow-up study

BACKGROUND

Postoperative recurrence (PR) occurs early after intestinal resection in >75% of Crohn's disease (CD) patients. No well-established strategy for long-term PR prevention is available. The aim was to prospectively evaluate the long-term endoscopic and clinical outcomes of postoperative CD on maintenance treatment with azathioprine (AZA), especially in patients who developed endoscopic lesions confined to the ileocolic anastomosis.

METHODS

Long-term AZA therapy (2-2.5 mg/kg/day) was initiated immediately after surgery in 56 consecutive patients who underwent a curative intestinal resection. Clinical and biological assessments every 3 months, as well as yearly endoscopic evaluation, were performed until the end of the study or clinical PR (CPR).

RESULTS

Thirty-seven patients (70%) showed mucosal lesions at endoscopy after a median of 12 months (range 12-60); however, in 15 of these patients lesions were confined to the anastomosis and only 6 showed endoscopic progression, but none of them developed CPR. Among the remaining 22 patients with endoscopic PR (EPR), 23% suffered a CPR during follow-up. Thirty percent of patients remained free of EPR after a median follow-up of 33 months (range 12-84). The cumulative probability of EPR was 44%, 53%, 69%, and 82%, at 1, 2, 3, and 5 years, respectively. No predictive factors of EPR were found.

CONCLUSIONS

Early postoperative use of AZA seems to delay EPR development in comparison to historical series or placebo groups in randomized controlled trials. Although usually considered as endoscopic recurrence, those lesions confined to the ileocolonic anastomosis are not likely to progress or to become symptomatic in the short term.