Assessing the Viability of Hadad Flap by Postoperative Contrast-Enhanced Magnetic Resonance Imaging

Abstract

Introduction: The Expanded Endonasal Approaches (EEAs) have been widely used for various skull base lesions. The reconstruction of the skull base defects is of vital importance to prevent postoperative complications. The vascular pediclednasoseptal flap (Hadad-Bassagasteguy flap) is used as a workhorse in reconstruction of majority of the defects. Aim: The purpose of this study was: (a) To assess the postoperative MRI appearance of vascularised pedicled nasoseptal flap for its viability; (b) To determine the variations in MRI that may suggest potential flap failure. Materials and Methods: A prospective study of 13 patients was done, who underwent endoscopic skull base surgery with reconstruction using the Hadad-Bassagasteguy flap. Preoperative MRI was done to assess the size, extent and location of the lesion and a postoperative MRI was done to evaluate flap configuration, enhancement patterns, location, flap thickness and signal intensity characteristics. Results: The postoperative MRI of all patients showed a detectable flap covering over the skull base defects forming an “open cup” appearance. They were uniformly isointense on T1weighted/ fat suppressed images to the adjacent nasal mucosa and hyperintense on T2-weighted images. On the MRI scans done after four weeks, all 13 of our patients had enhancing flaps. One flap migrated slightly to the left side; however, there was no Cerebrospinal Fluid (CSF) leak. Conclusion: Vascular pedicle nasoseptal (Hadad) flaps are being widely used. MRI is a very useful tool in assessing the viability of the flap postoperatively and to evaluate for variations that may suggest potential flap failure.

Keywords

• endonasal approach
• endoscopic surgery
• hadad-bassagasteguy flap
• nasoseptal flap
• reconstruction
• skull base surgery