Characterization of the Saddle Nose Deformity Following Endoscopic Endonasal Skull Base Surgery.

 The endoscopic endonasal approach (EEA) is commonly employed in skull base surgery for neoplasm resection. While nasal deformity following EEA is described, this study aimed to perform a detailed qualitative and quantitative assessment of the associated saddle nose deformity (SND) in particular.  This is a retrospective review of 20 adult patients with SND after EEA for resection of skull base tumors over a 5-year period at the University of Pittsburgh Medical Center.  Fifteen measurements related to SND were obtained on pre- and postoperative imaging. Statistical analyses were performed to evaluate differences between pre- and postoperative anatomies.  The most common EEA was transsellar. Reconstruction techniques included nine free mucosal grafts alone, eight vascularized nasoseptal flaps (NSFs), one combined free mucosal graft/abdominal fat graft, and one combined NSF/fascia lata graft. Imaging analysis showed a trend toward loss of mean nasal height, nasal tip projection, and nasolabial angle postoperatively. Subgroup analysis showed that patients with NSF reconstruction had a significantly decreased nasal tip projection (1.2 mm,  = 0.039) and increased alar base width (1.2 mm,  = 0.046) postoperatively. Patients without functional pituitary microadenomas demonstrated significantly increased nasofrontal angle and decreased nasal tip projection on postoperative imaging, in contrast to those with functional adenomas who had no measurable significant changes.  Clinically evident SND does not always lead to significant radiographic changes. This analysis suggests that patients who undergo surgery for indications other than functional pituitary microadenomas or who receive NSF reconstruction develop more marked SND on standard imaging tests.