Controlling inflammation is the first step in therapy for stricturing Crohn disease, Christina Ha, MD, told the audience at the Advances in Inflammatory Bowel Diseases (IBD) regional meeting.

Dr Ha is an associate professor of medicine and gastroenterologist with the Mayo Clinic Arizona in Scottsdale.

In diagnosing stricturing Crohn disease, she explained, “symptoms alone are not appropriate to diagnose a stricture and are not required. A disconnect between symptoms and stricture severity can exist.”

However, Dr Ha said, “cross-sectional imaging or ileocolonoscopy are sufficient to diagnose a small bowel stricture,” with magnetic resonance enterography (MRE) the preferred diagnostic modality. She cautioned that no single imaging technique can currently distinguish the inflammatory from the fibrotic component of a small bowel stricture.

Through endoscopy, stricturing can be diagnosed as luminal narrowing that makes it impossible or difficult to pass with an adult endoscope, she explained. On cross-sectional imaging, an increase of 25% in maximally thickened bowel wall area relative to normal adjacent bowel is a key diagnostic sign. Luminal diameter reduction by at least 50% measured relative to normal adjacent bowel is a signal of stricture.

Following diagnosis, the gastroenterologist must consider several other factors when determining a treatment strategy, Dr Ha continued. Is this stenosis inflammatory or fibrotic? Is the patient symptomatic? Are there associated conditions such as phlegmon, penetrating disease, abscess, dysplasia, or malignancy? Does the patient have any contraindications for medical therapy or for endoscopic therapy?

Dr Ha pointed out that strictures typically have both fibrotic and inflammatory components. “It’s very rare to see a purely fibrotic stricture; most have an inflammatory component as well. MRE is one of our better modalities to identify both inflammation and fibrosis in stricturing Crohn’s disease.”

One of the traditional nonoperative alternatives for management of stricturing Crohn is corticosteroids. In a study from 1983 of 26 patients with ileal or ileocolonic Crohn disease and small bowel obstruction, 24 patients achieved complete resolution of obstruction following a course of corticosteroids with or without a clear liquid diet, total parenteral nutrition (TPN), or nasogastric tube (NG). One patient showed clinical improvement and just 1 went to surgery, Dr Ha noted.

Among the patients who achieved complete resolution 7 had no recurrence of stricturing disease while 18 had a second obstruction. These patients were treated with a nonoperative program that included a clear liquid diet, sulfasalazine, corticosteroids, 6-mercaptopurine (6-M) and/or an NG tube. Again, all 18 had complete resolution but eventually all had another recurrence and 9 patients required surgical treatment.

The CREOLE study of adalimumab in stricturing Crohn disease showed promising results, she reported. At week 24, 64% of patients had achieved success; 30% of the entire cohort had prolonged success at 4 years and 50% of the cohort was free of surgery at 4 years, she stated. In this study no dilation was needed, patients did not receive corticosteroids, and no patients  withdrew due to complications or adverse event. “Patients respond better to adalimumab if they have a shorter duration of symptoms, a stricture of under 12 cm and proximal dilatation of less than 3 mm,” Dr Ha noted. “Maybe we can find a way to best identify patients who can respond to adalimumab for their stricturing Crohn’s disease.”

STRIDENT was a phase 4, single-center, open-label randomized controlled trial among 77 patients with Crohn’s disease with intestinal stricture(s) identified on MRI or ileocolonoscopy in which the intervention was high-dose adalimumab induction and escalation along with dose-optimized thiopurine, Dr Ha explained. The comparator was standard adalimumab monotherapy. Obstructive symptoms were graded on a 5-point Likert scale and the primary outcome was improvement in obstructive symptoms.

“At 12 months, 79% of patients receiving adalimumab and thiopurine and 64% of patients receiving adalimumab alone achieved improvement in obstructive symptoms,” she stated. After 6 months, however, monotherapy group did not do as well. “Stricturing disease is generally considered more severe disease, so these patients probably wouldn’t be put on monotherapy,” Dr Ha said.

In reviewing a comprehensive meta-analysis of patients with stricturing Crohn disease who were bio-naïve, bio-exposed, symptomatic or asymptomatic, and did or did not have anastomotic strictures, Dr Ha pointed out that anti-TNFs with or without immunomodulators and ustekinumab were the top choices.  

An alternative to surgical or medical therapy is endoscopic balloon dilatation. Dr Ha explained that this procedure is appropriate for symptomatic ileocolonic or colonic strictures, preferably isolated anastomotic strictures. It may also be used to treat upper GI strictures as well as inflamed and ulcerated stenosis.

The key question when considering endoscopic dilation, she said, “Is it short, straight, and safe?” Dr Ha cautioned that when a patient with long-standing Crohn disease presents with a small bowel stricture, there is a risk of malignancy, which must be factored into the decision about whether to pursue surgery.

Cross-sectional imaging is important to exclude penetrating complications, length, and angulation of strictures, she continued. A systematic review and meta-analysis found that among 1463 with 3213 dilatations, strictures under 5 cm were associated with surgery-free outcomes while each 1 cm increase was associated with an 8% increase in hazard for surgery. “Active disease was not associated with increased risk,” Dr Ha noted.

She reviewed technical parameters for endoscopic balloon dilation of fibrostenosing Crohn disease. Cross-sectional imaging prior to the intervention is essential, Dr Ha said. The maximal stricture length is 5 cm. The luminal diameter influences the initial balloon size. Balloon insufflation time should vary between 60 and 90 seconds, with a maximum of 3 steps for graduated dilation. “At the end of the procedure, 15-18 mm is adequate luminal diameter,” she said.

In one study, 90% of patients had successful balloon dilation, while less than 3% had complications. She cautioned that the gastroenterologist should carefully weight whether dilation is “a temporizing step. Is this a means to an end or a bridge to something else?” Repeat imaging 3 to 6 months after dilation may help clarify if further dilation is needed or appropriate. Optimizing medical treatment after dilation can lengthen the time between dilation, she added.

“Endoscopic dilation Is superior to intestinal stent placement,” according to results of research, Dr Ha said. The ProtDilat multicenter, open-label, randomized study of 80 patients with Crohn disease with no more than 2 symptomatic, predominantly fibrotic small bowel strictures compared the use of a fully covered self-expanding metal stent (FCSEMS) to endoscopic balloon dilation. Some 80% of the patients who underwent endoscopic balloon were free of new therapeutic intervention at 1 year of follow-up compared to 51% in the stent group. 97% of the stents migrated after just 2 days.

Endoscopic dilation is a good option for patients with an anastomotic stricture and stenosis of less than 4 to 5 cm, who have intermittent obstructive episodes and a long interval since any previous surgery or dilation, Dr Ha stated.

“With colonic strictures, proceed with caution ,” Dr Ha said. Among patients with inflammatory bowel disease and colonic strictures, about 3.5% will show signs of dysplasia or cancer, she cautioned. “The major risk factors for malignancy are disease duration, location of the stricture proximal to splenic flexure, and symptomatic large bowel obstruction.” She further stressed that tumor necrosis factor inhibitors do not cause strictures. “If you see a stricture in the setting of UC, you should have a suspicion of cancer.”

Surgery is indicated when dilation is technically difficult, the patient has long or multiple strictures, has experienced an early recurrence after dilation, and has deep ulcers or penetrating complications such as abscess, fistula, or phlegmon. Patients with dysplasia or malignancy or long-standing or significant prestenotic dilation should also be treated surgically.

In summary, she said, “Endoscopic dilation is indicated for strictures of under 5 cm, but perform imaging before dilation to exclude fistula, abscess and phlegmon. Serial dilation with or without

escalation of medical therapy is feasible, depending on patient preferences and symptom-free interval. Perform resection in case of fistula, abscess, phlegmon, or malignancy, and be careful to precisely survey colonic strictures.”

—Rebecca Mashaw

Ha, C. Stricturing Crohn’s Disease. Presented at: Advances in Inflammatory Bowel Diseases regional meeting. May 19, 2023. Boston, Massachusetts.