Endoscopic therapy of strictures in Crohnʼs disease

To cut is not to cure. Every clinician involved in caring for Crohn's disease (CD) patients is facing this dilemma. Although resection of stenotic or perforated intestinal segments is often unavoidable, surgical remission is only temporary. Endoscopically more than 70% of patients will have new lesions within a year and 40% will be symptomatic within 4 years.1 Biological therapies and immunosuppressives have been proven to induce complete mucosal healing, but the clinical challenge of fibrostenosis has not been eliminated by these novel therapeutic strategies. Recent retrospective data indicate that the increasing use of azathioprine in the last decade failed to decrease the need for CD-related bowel resection in a large French patient cohort.2 Uncontrolled transformation of resident mesenchymal cells into matrix-depositing myofibroblasts is most likely causing fibrosis in CD,3 but the underlying molecular mechanisms have not been unraveled. Since repeated bowel resections may result in short bowel syndrome, the quest for bowel conserving strategies over the last 25 years has introduced both endoscopic and surgical strictureplasty in clinical practice. Successful endoscopic dilation of anastomotic strictures in CD using through-the-scope (TTS) rigid balloons was first reported in 1981 and has emerged as an alternative to surgery for selected patients. TTS balloon dilation had been developed earlier for the dilation of peptic and caustic strictures of the esophagus. Careful patient selection is of paramount importance to optimize the outcomes of both endoscopic and surgical strictureplasty. Endoscopic balloon dilation is indicated for relatively short (maximally 5 cm), symptomatic strictures in the upper and lower gastrointestinal tract of the ileocolonic anastomosis or of intrinsic colonic strictures. These strictures are generally easily accessible. A carefully performed barium meal or CT/MR enteroclysis to assess the number of strictures, the length and angulation of the targeted lesion, and the presence of prestenotic dilation is mandatory to allow for a proper prediction of successful outcome. Several series have been published in the last 10 years (Table 1), with immediate success rates varying between 71% and 100%.4,–15 Outcomes and Complications of Published Series on Endoscopic Balloon Dilation for Crohn's Disease Strictures Outcomes and Complications of Published Series on Endoscopic Balloon Dilation for Crohn's Disease Strictures Passage of a conventional colonoscope through the dilated stricture is a good predictor of successful dilation, but alleviation of obstructive symptoms is the most important outcome after strictureplasty. The major complications of endoscopic strictureplasty include bleeding and perforation. In the reported series, 0%–11% of patients presented with a major complication. Perforations after endoscopic dilation are mostly concealed and can usually be managed conservatively. There is a theoretical risk of missing malignancy with endoscopic and surgical strictureplasty. Although isolated reports of ileal adenocarcinoma at the site of surgical strictureplasty have been published,16,–18 one should realize that even in CD patients this malignancy is exceedingly rare. The risk is more elevated in intrinsic colonic strictures and biopsies should be obtained from the stenotic segment. Symptom recurrence after endoscopic balloon dilation has been reported in 13%–100% of patients (Table 1). However, not all of these patients need surgery. Repeated dilation is a valid option, but the length of the symptom-free interval will be the main parameter used to decide between surgery and re-do endoscopic dilation. Because of suboptimal long-term outcomes of endoscopic balloon dilation, adjuvant techniques have been studied. In one series unsuccessful balloon dilatation was supplemented by carving the stricture with a sphincterotome.19 The incisions with the sphincterotome did not result in extra complications. Also, more recently, endoscopic stenting of ileocolonic stenoses has been reported in a limited number of patients, with beneficial outcomes.20 Intramural or topical corticosteroids in preventing restenosis is common practice in dilation of caustic esophageal strictures and has been reported in CD patients. Unfortunately, no prospective randomized study has ever been published as a full article. Ramboer et al8 reported a 100% immediate success rate in 13 patients with endoscopic dilation and intramural injection of corticosteroids after the procedure. Unfortunately, no follow-up data were provided. More recently, Singh et al,15 Lavy,12 and Brooker et al13 reported on intramural triamcinolone injection in 17, 10, and 14 patients, respectively. In the article by Singh et al15 only 1 in 10 successful dilations with steroid injection were associated with a recurrence long-term versus 31% in the conventionally dilated group, but these open-label data are not sufficient to advise steroid injection in every dilated stenosis. Prospective sham-controlled studies are needed. Finally, preliminary data from Raedler et al11 indicate that patients receiving budesonide along with azathioprine after dilation are more likely to have a good long-term outcome than patients receiving azathioprine alone. These data should be tested in a larger trial. The choice between endoscopic dilation and surgical strictureplasty is usually evident, since both techniques are indicated for different types of strictures. Endoscopic balloon dilation should be reserved for short and isolated CD-related stenoses accessible with conventional endoscopes, particularly at the ileocolonic anastomosis. Given the acceptable long-term avoidance of surgery and low complication rates, endoscopic dilation should be considered in these patients to avoid surgical resection. Surgical strictureplasty is indicated for multiple strictures, longer stenoses, and lesions beyond the reach of the endoscope. Ileocolonic or colo-colonic anastomoses are notably cumbersome for surgical strictureplasty, leaving endoscopic dilation as the best bowel-conserving option. However, both for endoscopic and surgical strictureplasty prior radiological documentation will aid in selecting patients and to avoid unnecessary procedures.