Management of complex perianal fistula in patients with Crohn disease

MRI: magnetic resonance imaging; EUA: exam under anesthesia; EUS: endoscopic ultrasound; TNF: tumor necrosis factor; CT: computed tomography.
* Colorectal surgery is consulted for EUA with abscess drainage. Rectosigmoid endoscopy is often performed during EUA to assess mucosal disease. Pelvic CT scan with intravenous contrast only is typically performed if abscess is suspected.
¶ Antibiotic therapy typically consists of either oral metronidazole or ciprofloxacin for two weeks.
Δ The timing for removal of setons relative to ongoing medical therapy is a joint decision involving the colorectal surgeon and gastroenterologist.
◊ Rectosigmoid endoscopy is often performed at the time of EUA.
§ Symptomatic improvement (eg, absence of rectal pain, fever) suggests abscess resolution.
¥ For patients with persistent perianal abscess despite initial drainage, subsequent intervention may include surgical drainage or interventional radiology procedure. After abscess is drained and infection is treated, medical therapy with anti-TNF agent can be initiated.
‡ Complete fistula closure is the therapeutic goal for most patients. For some patients with complex perianal fistulas, the achievable goal of therapy is symptomatic improvement (eg, less rectal pain, reduced drainage) and better quality of life but without complete fistula healing and closure.
† In addition to symptoms (eg, lack of drainage) and signs (eg, closure of external opening), options to assess fistula healing include pelvic MRI, rectal EUS and EUA. Testing method depends on initial presentation, prior testing, and clinician preference.
** Options for adjusting anti-TNF therapy for patients with nonhealing fistula include:

• Optimize dose of anti-TNF agent
• Begin a thiopurine (in addition to anti-TNF agent)
• Switch to a different anti-TNF agent
• Discontinue anti-TNF agent and begin an alternative biologic agent (eg, vedolizumab)