2026 Proffered Presentations
S061: DUAL VASCULARIZED FLAP RECONSTRUCTION IN ENDOSCOPIC SKULL BASE SURGERY FOR RADIORESISTANT TUMORS: OUTCOMES OF A MULTILAYERED VASCULARIZED STRATEGY
Esteban Ramirez Ferrer; Juan P Zuluaga-Garcia, MD; Shirley Y Su, MBBS; Ehab Y Hanna, MD; Franco DeMonte, MD; Shaan M Raza, MD; The University of Texas MD Anderson Cancer Center
Background: Endoscopic skull base reconstruction after resection of radioresistant tumors is challenging due to large dural defects, high-flow cerebrospinal fluid (CSF) leaks, and the frequent need for adjuvant radiation. While the nasoseptal flap (NSF) is the standard reconstructive option, single-layer closure may be insufficient in complex cases, particularly when local tissue has been compromised by prior treatment. Radiation-induced skull base osteonecrosis represents another high-risk scenario where durable closure is critical to restore function and permit further therapy. In such settings, adding a pedicled pericranial flap (PPF) provides a second vascularized layer that reinforces closure and may mitigate CSF-related and radiation-associated complications. This study reports institutional experience with multilayered reconstruction using NSF and PPF for high-risk skull base defects, including both post-tumor resection and radiation-induced osteonecrosis.
Methods: Patients who underwent endonasal endoscopic skull base surgery at a tertiary cancer center between January 2014 and July 2024 were retrospectively reviewed. Of 663 screened, 95 underwent reconstruction with a PPF. Ten met inclusion criteria for multilayered vascularized reconstruction with both NSF and PPF; cases with only a single pedicled flap were excluded. Demographics, pathology, defect location, prior treatments, and intraoperative findings were collected. Reconstruction was standardized with the NSF as the intranasal layer and the PPF harvested through a frontal or bicoronal incision, tunneled subgaleally, and positioned as an overlay, passed through the frontal sinus after a Draf III sinusotomy. Fascia lata or synthetic grafts were used as adjuncts when indicated. The primary outcome was reconstruction-related complications, defined as postoperative CSF leak, flap infection or necrosis, or skull base osteomyelitis. Secondary outcomes included reoperation, lumbar drain use and duration, and time to initiation of adjuvant therapy.
Results: Ten patients were analyzed (4 females, 6 males; mean age 45.5 years, median 46.5). Six had prior endoscopic resections, two biopsies, and two other procedures; four had received radiation before reconstruction. Pathologies included five chordomas, one adenocarcinoma, one adenoid cystic carcinoma, one sinonasal neuroendocrine carcinoma, and two cases of radiation-induced necrosis. Tumor extension into the nasal cavity was seen in two cases. By anatomical zone, five patients had defects in zone 1, three in zones 1 and 3, one in zones 2 and 3, one in zone 3, and one in zone 2. Bilateral NSF was used in one case. A perioperative lumbar drain was placed in four patients, maintained for a mean of 4 days with drainage between 5–10 cc/hour. Postoperative CSF leak occurred in one patient, a chordoma without prior surgery or radiation, requiring surgical revision for flap repositioning. No further reconstruction-related complications were observed.
Conclusion: Multilayered reconstruction with NSF and PPF is a safe and effective strategy for high-risk skull base defects, including radioresistant tumors and radiation-induced osteonecrosis. In this cohort, the approach demonstrated a very low CSF leak rate and no major morbidity, despite frequent prior surgery and radiation. These results support the reliability of dual vascularized flap reconstruction when durable closure is paramount and underscore its value for complex endoscopic skull base surgery