Resection margins and recurrent Crohn's disease.

Recurrence rates following surgery vary depending on the criteria used to define recurrence (eg: endoscopic versus clinical evidence of disease), patient population, completeness of follow-up, and method of analysis of results. Thus, comparison of recurrence rates from different centers is often difficult. The effect of various factors on the rate of recurrence has been assessed. Of these, the significance of microscopic disease at the resection margin, and the optimal length of the normal resection margin remain highly controversial. There is mounting evidence that microscopic changes are present throughout the gastrointestinal tract of patients with Crohn's disease. Thus, the presence or absence of disease at the margin may merely be a chance phenomenon. Although the data is inconclusive, it appears that ensuring that the margin is free of microscopic disease is of little benefit in preventing recurrence. Similarily, there is no conclusive evidence that a wider resection results in a lower recurrence rate. On the other hand, a policy of radical resections is potentially dangerous, since the patient may be at greater risk of developing significant malabsorptive symptoms with repeated resections. Thus, it is recommended that for most patients, only the small bowel that is grossly involved with disease be resected and that the surgeon should always be aware of the risk of short bowel syndrome.