Aim The mid-term appearance of the filtering bleb and surgical outcome following tunneltrabeculectomy, in which protective measures were carried out to avoid contact between the mitomycin C (MMC) and the conjunctival flap, are presented. Methods In a retrospective study the records of 20 consecutive patients who had undergone tunnel-trabeculectomy Z24 months earlier, using fornix-based conjunctival flap and MMC (0.4 mg/ml) application were evaluated. Inclusion criteria were patients in whom: (I) the MMC-socked sponge was applied without contact with the conjunctival flap; (II) during MMC washout, a second Weck cell sponge was held anterior to the conjunctival flap, to protect the flap from mitomycin contact during its back-flow. Excluded were five patients who either did not complete 24 months of follow-up (n ¼ 4) or underwent an intraocular surgery during that period (n ¼ 1). Results After 24-32 (26.972.2) months, the filtering bleb was completely vascularized and thick in 13/15 patients (86.7%), mostly vascularized with some para-limbal thick cysts in one and avascular and cystic in another. Mean intraocular pressure (IOP) dropped from a preoperative level of 25.377.0 mmHg with 3.570.9 hypotensive medications to 13.972.9 mmHg with 0.971.1 medications (Po0.0001, Wilcoxon test). Of the five excluded patients, the IOP ranged between 10 and 16 mmHg with 0-1 medications at the last examination, 1-15 months postoperatively. Conclusion In this pilot study, an intraoperative protection of the conjunctival flap from mitomycin contact was mostly associated with a vascularized and thick filtering bleb after mid-term follow-up.Further controlled prospective studies are required to confirm these observations.