Free-Tissue Transfer in the Endoscopic Era: Evolving Role of the Top Tier of Skull Base Reconstruction

Background: As the field of endoscopic skull base surgery continues to evolve in the management of complex pathology, comparable advances in skull base reconstruction have also been required. Ranging from a variety of avascular or synthetic techniques to pedicled, vascularized flap reconstruction, innovation in the reconstructive ladder has continued to push the boundaries for invasive pathology managed through endoscopic techniques. However, in cases where standard reconstructive options are unavailable or fail, microvascular free-tissue transfer or free flap has become the top tier option for skull base reconstruction after endoscopic endonasal surgery.

Objective: Although microvascular free-tissue transfer has been discussed in the reconstructive ladder, there is a paucity of literature characterizing the unique indications for its use and minimally invasive techniques for its application to the skull base via the endonasal corridor. We aimed to characterize our institutional experience with microvascular free tissue transfer for reconstruction of the skull base via minimally invasive approaches and endoscopic assistance.

Methods: Between 2014 and 2019, we performed a retrospective review of all cases in which microvascular free tissue transfer was required for skull base reconstruction in the setting of either prior or concurrent endoscopic endonasal surgery. Upon review, four distinct cases were identified highlighting a variety of combined endonasal and open surgical techniques.

Results: Microvascular free tissue transfer was the primary surgical intervention in two patients and the salvage reconstructive option in two patients. In the primary group, the indication for skull base reconstruction was a long-standing history of refractory osteoradionecrosis with associated osteomyelitis of the skull base and craniovertebral junction following chemoradiation treatment of nasopharyngeal carcinoma. In these patients, a combined transoral and endonasal surgical approach was utilized, with endoscopic guidance for inset of the free flap via the endonasal corridor. In the two cases of salvage reconstruction for persistent CSF leak following endonasal tumor resection, both patients had large, complex tumors, and multiple prior operations. One was a chondrosarcoma of the inferior clivus extending to C1 and the other was a recurrent pituitary adenoma involving the planum and sella. With regard to the pituitary adenoma, the patient had undergone multiple rounds of radiation treatment as well. In both cases, a minimally invasive technique via a lateral rhinotomy and endoscopic endonasal approach was utilized for inset of the free flap at the skull base defect. In all four cases, definitive skull base reconstruction was achieved with no incidence of postoperative CSF leak or revision surgery required.

Conclusion: As we continue to push the boundaries of endoscopic approaches for the management of intricate skull base pathologies, the role of various reconstructive options becomes critical to understand. Although the indication for using free tissue transfer for skull base reconstruction is decidedly rare, this top tier option of the reconstructive ladder is highly effective, and should be considered for unique situations in which other methods have failed or are ill advised. Our institutional experience provides insight into the unique role of free-tissue transfer for skull base reconstruction via a minimally invasive surgical approach.

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Artikel online veröffentlicht:
12. Februar 2021