Newly designed double-vascularized nasoseptal flap to prevent restenosis after endoscopic modified Lothrop procedure (Draf III): laboratory investigation

Despite advances in endoscopic approaches, instrumentations and imaging guidance systems, the management of frontal sinus is still challenging. Failure of the endoscopic procedure and restenosis of the newly formed ostium have been demonstrated even with large frontal sinusotomy. We describe a newly designed double nasoseptal flap to cover the bare bone after endoscopic modified Lothrop procedure (EMLP). Five fresh, double-injected cadavers were dissected through an endoscopic endonasal approach. Posteriorly based nasoseptal flap on one side and laterally based nasoseptal flap on the other side were harvested before performing wide EMLP. Feasibility of the procedure, versatility of the flap, coverage area and measurements were calculated. Harvesting the mucoperichondrial/mucoperiosteal flap over the septectomy site was straightforward step. Two different designed flaps (one on each side) are more practical to avoid torsion of the flap. The flap measures 2 7 3 cm on average that was able to cover the bare bone of the anterior and posterior wall of frontal sinus. Osteoneogenesis and progressive osteoplastic activity after EMLP plays a major role in restenosis of frontal sinus. Vascularized nasoseptal flap helps in preventing closure of the newly formed ostium. Applying these flaps over the bare bone enhances the healing process and minimizes the crust formation