3 recent small studies have shown that use of rectal endoscopic ultrasound (REUS) is associated with significant improvement in outcomes when patients were referred to surgeon for management of perianal fistulas and abscesses.MRI was also found helpful in diagnosing perianal fistulas and the two modalities (REUS and MRI) may be the most helpful in diagnosis and followup of perianal fistulas.
In a small study using both REUS and MRI to guide and monitor treatment, 86% (18 of 21) of patients attained closure of fistula initially and 76% (16/21) had long term (mean of 68 weeks or roughly 16 months) cessation of drainage.
Several small studies have also demonstrated that external healing of fistula does not necessarily correspond to internal healing and reduction in inflammation.
In one small study, those patients whose REUS continued to show internal inflammation at 10 weeks after initiation of treatment were most likely to have recurrence of fistula over time. At week 10 only 5/30 patients had closure of tract based on REUS despite 15/30 having external closure of tract.
Expert opinion is that REUS should be used in the diagnosis process and to monitor treatment of perianal fistulas and abscesses.
Expert opinion is that recommended treatment include antibiotics (cipro may have slight advantage over flagyl) and treatment with anti-TNF alpha meds. Immunomodulator may be added based on individual case analysis.
Even with anti-TNF alph meds, only 55% of patients achieved complete fistula closure (leaving 45% with incomplete closure or none).
summary of findings posted at www.thecdwg.org