The role of pelvic MRI in assessment of combined surgical and Infliximab treatment for perianal Crohn's disease

AIM: To evaluate the role of pelvic MRI in diagnosis and assesment of combined surgical and infliximab treatment of perianal Crohn's disease (PACD). METHOD: 24 patients with signs of PACD were prospectively evaluated. They were previously treated with azathyoprin for a period of 6 months to 7 years and antibiotics and than started on Infliximab 5 mg/kg (IFX) at 0,2 and 6 weeks induction protocol. Luminal CD activity was assesed by colonoscopy. Perianal Disease Activity Index (PDAI) was calculated to evaluate perianal fistulae activity. Surgical examination under anesthesia (EUA) was performed and noncutting seton placed where appropriate. Pelvic MRI was performed in each patient before Infliximab treatment, and in half of the patients after IFX. MRI criteria were used to asses activity and remission of PACD. RESULTS: 14/24(58.5%) patients had ileocolitis, 10/24 (41.5%) colitis, and in 22/24(91.7%) rectum was affected. Median disease duration was 5.5+2.5 years. MRI revealed simple fistula in 4/24 (16.7%) and complex fistula in 20/24 (83.3%) patients. Abscess was present in 19/24(79%) patients. Enterocutaneous and recto-vaginal fistula was found in 2(8.3%) and 3(12.5%) patients, respectively. Median PDAI before and 8 weeks after IFX treatment was 8.3+2.08 and 3.5+1.03, respectively (p=0.00064). Incomplete response (reduction fistulae drainage by 50%) was found in 10/24(42%) patients, complete response (no drainage) in 11/24 (46%) patients, while in 3/24(12.5%) new fistula opened. Control pelvic MRI was performed in 13/24 (54%) patients. Of those, 9/13(69%) had complete remission according to MRI criteria. Seton was removed after second IFX dose in 15/24 (62.5%) patients and placed again in 2/24 (8%) patients 4 months after completion of IFX treatment. CONCLUSION: In patients with PACD, pelvic MRI before and after IFX treatment is an important diagnostic tool to asses fistula tract localization, reveal abscess, planning adequate treatment approach and assess the effect of treatment. Surgical decision to remove seton was in accordance with MRI criteria for remission in PACD.