A comprehensive algorithm for anterior skull base reconstruction after oncological resections

Abstract

Objective: To present our method for anterior skull base reconstruction after oncological resections.

Methods: One hundred nine patients who had undergone 120 anterior skull base resections of tumors (52 malignant [43%], 68 benign [57%]) via the subcranial approach were studied. Limited dural defects were closed primarily or reconstructed using a temporalis fascia. Large anterior skull base defects were reconstructed by a double-layer fascia lata graft. A split calvarial bone graft, posterior frontal sinus wall, or three-dimensional titanium mesh were used when the tumor involved the frontal, nasal, or orbital bones. A temporalis muscle flap was used to cover the orbital socket for cases of eye globe exenteration, and a rectus abdominis free flap was used for subcranial-orbitomaxillary resection. Pericranial flap wrapping of the frontonaso-orbital segment was performed to prevent osteoradionecrosis if perioperative radiotherapy was planned.

Results: The incidence of cerebrospinal fluid (CSF) leak, intracranial infection, and tension pneumocephalus was 5%. Histopathological and immunohistochemical analysis of fascia lata grafts in reoperated patients (n = 7) revealed integration of vascularized fibrous tissue to the graft and local proliferation of a newly formed vascular layer embedding the fascial sheath.

Conclusion: A double-layer fascial graft alone was adequate for preventing CSF leak, meningitis, tension pneumocephalus, and brain herniation. We describe a simple and effective method of anterior skull base reconstruction after resections of both malignant and benign tumors.

Figure 1

The fascia lata technique for anterior craniobasal reconstruction in a 45-year-old male with olfactory groove meningioma (T_4AN₀M₀). (A) An intraoperative view of the craniobasal defect following tumor removal. (B) The fascia lata sheath has been applied to the defect. (C) Preoperative sagittal T1 MRI of the anterior cranial fossa. (D) Postoperative sagittal T1 MRI of the anterior cranial fossa 24 months following surgery. The arrow indicates the enhancement of the fascia.

Figure 2

Orbital reconstruction following subcranial resection in a 28-year-old patient with T_4AN₀M₀ squamous cell carcinoma. (A) The orbita was reconstructed with temporalis muscle rotational flap. The skull base was reconstructed with a double-layer fascia lata. (B) The periorbit was reconstructed with the nasofronto-orbital bone segment and with titanium mesh. Wrapping of the frontonaso-orbital segment was accomplished with a pericranial flap (arrow). (C) A picture of the patient 12 months after surgery. (D) A postoperative T1 MRI shows the area of reconstruction.

Figure 3

Reconstruction following subcranial resection, orbital exenteration, and radical maxillectomy in a patient with T_4AN₀M₀ squamous cell carcinoma. (A) The surgical defect after resection of the superior part of the tumor via the subcranial approach. (B) The surgical defect after resection of the inferior part of the tumor via an extended Weber-Fergusson incision. (C) Reconstruction of the orbita and maxilla was achieved using a rectus abdominus free flap and obturator. The anterior skull base was reconstructed with fascia lata. (D) Postoperative results 30 days after surgery.

Figure 4

Reconstruction of a patient with osteoradionecrosis of the frontonaso-orbital segment, performed 24 months after excision of squamous cell carcinoma. (A) Preoperative picture of the patient showing extrusion of the titanium plates through the skin. (B) Reconstruction of the bony segment was performed with a split calvarial bone graft. (C) The surgical defect following removal of the necrotic bone. (D) Postoperative results 6 months after surgery.

Figure 5

Neovascularization of the fascia lata graft 12 months after surgery in a case with recurrent tumor (H & E staining). Microscopical examination shows fibroblasts embedded in a dense collagenous stroma (higher arrow). Note the presence of neovascularized channels lined by endothelial cells (lower arrow). The graft has been replaced with a viable dense fibrocollagenous tissue. (20 × magnification.)