Fistula Plug in Fistulising Ano-Perineal Crohn's Disease: a Randomised Controlled Trial.

BACKGROUND AND AIMS: Anal fistula plug [AFP] is a bioabsorbable bioprosthesis used in ano-perineal fistula treatment. We aimed to assess efficacy and safety of AFP in fistulising ano-perineal Crohn's disease [FAP-CD]. METHODS: In a multicentre, open-label, randomised controlled trial we compared seton removal alone [control group] with AFP insertion [AFP group] in 106 Crohn's disease patients with non- or mildly active disease having at least one ano-perineal fistula tract drained for more than 1 month. Patients with abscess [collection ≥ 3mm on magnetic resonance imaging or recto-vaginal fistulas were excluded. Randomisation was stratified in simple or complex fistulas according to AGA classification. Primary end point was fistula closure at Week 12. RESULTS: In all, 54 patients were randomised to AFP group [control group 52]. Median fistula duration was 23 [10-53] months. Median Crohn's Disease Activity Index at baseline was 81 [45-135]. Fistula closure at Week 12 was achieved in 31.5% patients in the AFP group and in 23.1 % in the control group (relative risk [RR] stratified on AGA classification: 1.31; 95% confidence interval: 0.59-4.02; p = 0.19). No interaction in treatment effect with complexity stratum was found; 33.3% of patients with complex fistula and 30.8% of patients with simple fistula closed the tracts after AFP, as compared with 15.4% and 25.6% in controls, respectively [RR of success = 2.17 in complex fistula vs RR = 1.20 in simple fistula; p = 0.45]. Concerning safety, at Week 12, 17 patients developed at least one adverse event in the AFP group vs 8 in the controls [p = 0.07]. CONCLUSION: AFP is not more effective than seton removal alone to achieve FAP-CD closure.

Interposition vein cuff and intimal hyperplasia: an experimental study.

OBJECTIVE: There is some evidence to suggest that prosthetic distal bypass graft patency can be improved, and the risk of intimal hyperplasia diminished, by interposing a distal vein cuff. We studied intimal remodeling in an end-to-side distal prosthetic anastomosis constructed with and without a vein cuff. METHODS: Twenty-four prosthetic bypasses were constructed with (N=12) or without (N=12) a distal vein cuff in 12 pigs. At 10 weeks, the 20 anastomoses and adjacent arteries from the surviving 10 pigs were studied by histology, immunohistochemistry and morphometry. RESULTS: Intimal hyperplasia was significantly less on all zones of the arterial floor and all suture zone of arteries anastomosed with a vein cuff than within arteries anastomosed without a vein cuff (0.11 versus 0.34; p=0.001 and 0.35 versus 1.19; p=0.0001, respectively). Intimal hyperplasia was also more prominent within the vein cuff than within the recipient artery, with or without a vein cuff (1.35 versus 0.38; p=0.0001). CONCLUSION: An interposition vein cuff at the distal anastomosis between a prosthesis and an artery alters the distribution of intimal hyperplasia. By acting as an expansion chamber where intimal hyperplasia can develop harmlessly, the vein cuff may protect the arterial anastomosis from stenosis.