Use of Collagen Matrix for Skull Base Reconstruction following Endoscopic Endonasal Resection of Pituitary Adenoma

Background Skull base reconstruction following endoscopic endonasal approach (EEA) for skull base lesions is of paramount importance to avoid postoperative CSF leak, which is the most common complication following EEA. Different materials and techniques have been described for skull base reconstruction.

Objective To assess the efficacy and safety of collagen matrix in reconstruction of skull base defects following resection of pituitary adenomas via EEA.

Methods We retrospectively reviewed the records of all patients who were diagnosed with pituitary adenomas that were resected solely via EEA at our medical center between July 2010 and June 2017. We included only cases in whom this was the first surgical procedure or treatment and in which collagen matrix was used for skull base reconstruction alone or with a simple graft. All patients in which vascularized flaps were used were excluded. Preoperative clinical assessment, radiographic studies, intraoperative findings, technique of skull base reconstruction, and type of pituitary adenomas were recorded and analyzed. The incidence of postoperative CSF leak was identified and correlated with the type of skull base reconstruction, as well as other variables including patient demographic, type of pituitary adenomas, extent of surgical resection, and histopathological diagnosis.

Results Our search yielded 291 patients with pituitary adenomas who underwent surgical resection via EEA and in whom collagen matrix was utilized for reconstruction of the skull base. Forty-six patients had recurrent adenomas, and in 18 patients a vascularized flap (nasoseptal) was used for reconstruction and thus these patients were excluded from our analysis. Our final cohort had 227 patients (112 males and 115 females). The average age of patients was 53 years (range: 14–87 years). The maximal diameter of adenomas ranged between 2 and 68 mm (average: 22.5 mm). We achieved gross total resection in 86.3% of cases, subtotal resection in 11.8%, and partial resection in 1.7%. Collagen matrix was used alone for skull base reconstruction in 48 cases, while it was combined with middle turbinate mucoperiosteal graft in 167 cases, middle turbinate mucoperiosteal graft and autologous leukocyte and platelet-rich fibrin (L-PRF) graft in 8 patients, fat in 2 cases, and other types of grafts in 2 cases. Intraoperative CSF was encountered in 86 patients (37.8%). A postoperative CSF leak occurred in only seven patients and the overall postoperative CSF leak rate in the series was 3%. Postoperative CSF leak was managed successfully via EEA with the utilization of collagen matrix in all cases. There were no cases of infection (meningitis or sinonasal) associated with the use of the collagen matrix.

Conclusion This study suggests that collagen matrix yields similar results to autologous tissue without donor-site morbidity. It can be considered safe for skull base reconstruction following EEA for resection of pituitary adenomas, and for repair of postoperative CSF leak. It can be used alone in case of low-flow CSF leak, or combined with other grafts in case of high-flow CSF leak.