The purpose of this study is to demonstrate the utility of porcine small intestinal submucosa (SIS) as a graft material that may aid in the natural healing process of freshly exposed bone and cartilage in the nasal cavity.

Patients who undergo endoscopic endonasal skull base surgery, and may require nasoseptal flap placement as part of skull base reconstruction, will be informed, consented and enrolled for participation. If the intraoperative decision is ultimately made for harvest and placement of full-length nasoseptal flap by each individual surgeon, patients will then be consecutively, sequentially randomized to use of either:

• Thin Doyle silastic sheet placement alone over the resulting exposed septum cartilage/bone (20 randomly assigned patients)
• 2x3 cm Biodesign™ SIS perforated mesentery graft surface placement plus overlying Doyle silastic sheet placement over the resulting exposed septum cartilage/bone. (20 randomly assigned patients)

When used, Biodesign graft will be soaked in sterile saline out of the packaging, and placed as an intact single sheet over the exposed bone nasal septum bone/cartilage (without trimming). For uniformity and ease of future analysis, the bottom edge of the graft will be placed parallel to, and proximal to, the nasal floor cut edge remnant mucosal surface as possible. Except for a thin Doyle silastic sheet to cover the graft site, no additional reinforcement (suture/tissue glue) will be placed for those patients in the Biodesign graft arm.

Time Points and Study Parameters:

• All enrolled patients will have Doyle silastic sheeting removed only at 2 weeks post-op.
• All patients will receive 250cc normal saline topical nasal rinses starting at 14 days until 120 days post-op.
• No topical irrigation additives (budesonide/mupirocin) will be administered over 12 weeks.

All patients will be assessed at 2 weeks, 6 weeks and 12 weeks following randomization and entry into this study.

Inclusion Criteria:

• Elective transnasal endoscopic skull base surgery where closure with a large nasoseptal flap (NSF) is anticipated (exposure of >75% of the ipsilateral nasal septum bone/cartilage)
• Patients without nutritional compromise or otherwise debilitated
• Patients who are able to consent for themselves

Exclusion Criteria:

• Bilateral nasoseptal flap (NSF) placement in the same operative setting
• Patients without significant bone/cartilage exposure to incorporate an intact 2x3 cm graft
• Patients requiring 24 hour supplemental oxygen via nasal cannula
• Patients who cannot consent for themselves

12 weeks