The MR Imaging Appearance of Endoscopic Endonasal Skull Base Defect Reconstruction Using Free Mucosal Graft.

OBJECTIVE: At our institution, skull base reconstruction using a free mucosal graft from the nasal cavity floor has been the standardized technique after pituitary adenoma resection via transsellar approach. This study describes the expected appearance of the reconstruction on postoperative MRI scans and assesses its integrity and impact on the sinonasal cavity.

METHODS: Fifty patients were selected, and their EMR were reviewed for postoperative course, SNOT-22 scores, and nasal endoscopy reports. A total of 116 postoperative MRI scans were available to evaluate 1) the appearance and thickness of the graft, 2) the enhancement of the graft, and 3) the T2 signal in sphenoid sinus as a potential indication for inflammatory disease.

RESULTS: There was no significant change in the thickness of the graft over time. Except for the 7 scans that were obtained without IV contrast, all scans showed enhancement of the graft. About half of the patients displayed persistent T2 hyperintense signal at 12 and 24 months. However, this was not clinically significant, as postoperative SNOT-22 scores demonstrated minimal sinonasal impact.

CONCLUSION: Postoperative MRI surveillance scans demonstrated a stable appearance of the graft that mimics the native mucosa, with enhancement through time, reflecting its robust vascularization and well integration to the skull base. Although persistent T2 hyperintense signal was detected in the sphenoid sinus, clinical evidence based on nasal endoscopy reports and SNOT-22 scores indicated minimal sinonasal morbidity.