Indocyanine Green Fluorescence to Evaluate Nasoseptal Flap Viability in Endoscopic Endonasal Cranial Base Surgery.

 The pedicled nasoseptal flap (NSF) has dramatically reduced postoperative cerebrospinal fluid leakage following endoscopic endonasal approach (EEA) surgery. Although rare, its arterial supply may be damaged during harvest or may be preoperatively damaged for numerous reasons. Early recognition permits harvesting a contralateral flap before sacrificing its pedicle as part of the surgical exposure or use of an alternative flap.  Technical feasibility study and case series.  Tertiary care university-associated medical center.  Five patients requiring an EEA with NSF reconstruction.  During NSF harvest, intravenous indocyanine green (IVICG) was administered, and a customized endoscopic system was used to visualize the emerging fluorescence. At the end of each case, just before final positioning of the NSF, additional IVICG was administered, and the custom endoscope was again introduced to evaluate fluorescence.  In four patients, the entire NSF fluoresced brightly with IVICG on initial harvest and before final positioning. One patient showed heterogeneous fluorescence of the pedicle and distal parts of the NSF at both stages. All NSFs healed well without complication.  IVICG facilitates real-time evaluation NSF's arterial supply. This may provide early recognition of arterial compromise, allowing the harvest of alternate flaps or modification of surgery.