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 freemucosal graft (endonasal extended mucoplasty, EEM) to repair mucosal defects afteran extended ethmoid-sphenoidotomy.Methods:A human cadaveric study (radiological and anatomical dissection) and anin vivo study in surgical patients with CRSwNP were performed. The EEM areaswere compared between 3D reconstruction from CT scans and anatomical/surgicaldissections, both in cadaver specimens and in patients. Feasibility was assessed bycorrelation between the EEM area on CT scans and when harvested in cadaversand when grafted in patients. Usefulness was assessed by the degree of coverageof the EEM in the surface exposed after an extended ethmoid-sphenoidotomy.Both feasibility and usefulness were assessed in cadaveric specimens (n = 15) andpatients (n = 4).Results:Fifteen cadaveric specimens and 4 patients with bilateral CRSwNP wereincluded. The mean (SD) areas obtained in the cadaveric radiological and anatomicalstudies were 9.44 (2.07) cm2and 8.03 (1.36) cm2, respectively (intraclass correlationcoefficient 0.59, moderate correlation), and in 3D reconstruction for operatedpatients were 10.32 (0.98) cm2and 11.27 (2.44) cm2, respectively. The coverage ofthe ethmoidal roof in the cadaveric dissection study was 100%, from the anteriorethmoidal artery to the posterior ethmoidal artery, covering the planun sphenoidaleup to 75% in the case series. In 87.5% of the cases, up to 50% of the papiracea lam-ina 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 dur ing surgery for CRSwNP. Level of Evidence: NA.