Pre-Operative Planning for Anterior Skull Base Reconstruction Using Pericranial Flaps: A Cadaveric Study on Radiologic Measurements

Background: Skull base reconstructive surgeries frequently utilize vascularized flaps for the treatment of anterior skull base defects. Reconstructive requirements vary based on the size of the defect. There has been significant interest in the use of pericranial flaps as an alternative to nasoseptal flaps in skull base reconstruction. The reconstruction length required is usually estimated intra-operatively, although there has been growing interest in the literature for pre-operative radio-anatomical analysis of flap length. Many studies have focused on the utilization of anatomical measurement software for pre-surgical planning in different contexts, such as nasoseptal flap measurements for anterior skull base defects. Comparatively, there has been little research done on software measurement of pericranial flaps for reconstructive procedures. Aim: This study aims to assess the reliability of radio-anatomic measurement and validate the usage of software to directly measure pericranial flaps. Objective: To radiologically measure skull base coverage requirements in cadaveric models. Methods: Five high-resolution head CT scans of cadaveric donors were obtained for analysis. Using InVivo7 software, a three-dimensional DICOM viewer platform, eight variables were measured in coronal and sagittal views: inter-frontal sinus distance, glabella to coronal suture, frontal sinus to anterosuperior cribriform plate, frontal sinus to postero-inferior cribriform plate, frontal sinus to antero-superior clivus, frontal sinus to postero-inferior clivus, frontal sinus to nasopharynx, and between eyebrows. Two independent researchers obtained these measurements on each of the five CT scans using the software’s distance and polyline tool along fixed points. Inter-rater reliability between the two researchers was evaluated with intra-class correlation coefficients (ICC). Results: For each variable, measurements for both raters were collected. The following results are reported in Table 1 . Inter-rater reliability showed excellent agreement, with a Cronbach’s Alpha score of 1 and a combined intra-class correlation of 0.99 (p