Radioanatomical study of the extended free nasal floor mucosal graft and its clinical applications

Objectives To perform a radio‐anatomical evaluation of the nasal cavity floor free mucosal graft (endonasal extended mucoplasty, EEM) to repair mucosal defects after an extended ethmoid‐sphenoidotomy. Methods A human cadaveric study (radiological and anatomical dissection) and an in vivo study in surgical patients with CRSwNP were performed. The EEM areas were compared between 3D reconstruction from CT scans and anatomical/surgical dissections, both in cadaver specimens and in patients. Feasibility was assessed by correlation between the EEM area on CT scans and when harvested in cadavers and when grafted in patients. Usefulness was assessed by the degree of coverage of the EEM in the surface exposed after an extended ethmoid‐sphenoidotomy. Both feasibility and usefulness were assessed in cadaveric specimens (n = 15) and patients (n = 4). Results Fifteen cadaveric specimens and 4 patients with bilateral CRSwNP were included. The mean (SD) areas obtained in the cadaveric radiological and anatomical studies were 9.44 (2.07) cm2 and 8.03 (1.36) cm2, respectively (intraclass correlation coefficient 0.59, moderate correlation), and in 3D reconstruction for operated patients were 10.32 (0.98) cm2 and 11.27 (2.44) cm2, respectively. The coverage of the ethmoidal roof in the cadaveric dissection study was 100%, from the anterior ethmoidal artery to the posterior ethmoidal artery, covering the planun sphenoidale up to 75% in the case series. In 87.5% of the cases, up to 50% of the papiracea lamina was covered. Conclusion The EEM have shown to be a feasible and useful grafting technique to repair skull base defects after performing an extended ethmoid‐sphenoidotomy during surgery for CRSwNP. Level of Evidence NA.