Reconstruction of Skull Base and Fronto-orbital Defects following Tumor Resection

Abstract

Reconstruction of the anterior skull base and fronto-orbital framework following extensive tumor resection is both challenging and controversial. Dural defects are covered with multiple sheets of fascia lata that provide sufficient support and avoid herniation. Plating along the skull base is contraindicated. After resection of orbital walls, grafting is necessary if the periosteum or parts of the periorbital tissue had to be removed, to avoid enophthalmus or strabism. Free bone grafts exposed to the sinonasal or pharyngeal cavity are vulnerable to infection or necrosis: therefore, covering the grafts with vascularized tissue, such as the Bichat fat-pad or pedicled temporalis flaps, should reduce these complications. Alloplastic materials are indispensable in cranial defects, whereas microsurgical free tissue transfer is indicated in cases of orbital exenteration and skin defects. The authors review their experience and follow-up of 122 skull base reconstructions following extensive subcranial tumor resection. Most significant complications were pneumocranium in 4.9%, CSF leaks in 3.2%, and partial bone resorption in 8.1%.

Figure 1

Extensive esthesioneuroblastoma Hyams grade 4 with intra- and extracranial tumor extension. (A) Preoperative axial MRI, left, and the corresponding intraoperative view after tumor removal, right. S, sphenoid; B, resected dura with exposed brain tissue. (B) Dural repair with fascia lata. See text. S, sphenoid. (C) Postoperative sagittal MRI demonstrating absence of the tumor and presence of fascia lata layers with no brain herniation.

Figure 2

Malignant embryonal tumor in a 10-year-old girl. (A) Subcranial exposure. D, dura opened; C, chiasm with bilateral optic nerves exposed. (B) Fleece-bounded tissue sealing using a collagen sponge coated with fibrinogen and thrombin coagulation factors (TachoSil^®).

Figure 3

Reconstruction after resection of both medial orbital walls including the periosteum. (A) Intraoperative view. G, calvarial bone graft fixed with a microplate; S, sphenoid. (B) Postoperative coronal and axial CT scan showing accurate positioning of the grafts.

Figure 4

Schematic drawing of the midface reconstruction with bone grafts aligned toward the maxillary sinus by the pedicled buccal fat-pad.

Figure 5

Temporoparietal fascia flap in combination with full thickness calvarial bone graft, supplied by the superficial temporal artery.

Figure 6

Representative case for the reconstruction of the orbital wall and floor in a leiomyosarcoma. (A) Preoperative coronal MRI showing tumor extensions toward the orbital cone, nasal cavity, maxillary sinus, and resorption of the palate. (B) Corresponding postoperative MRI. Absence of the tumor, contrast-enhanced layers of fascia lata and orbital walls. The eye was preserved. (C) Intraoral view showing the reconstructed orbital floor with a pedicled calvarial bone graft. O, orbit; S, sphenoid. (D) Subcranial view of the medial wall fixed with microplates. F, fascia lata; O, orbit; S, sphenoid. (E) Postoperative coronal CT scan demonstrating the accurate reconstruction of the orbit and maxilla. (F) Postoperative view of the patient following reconstruction. Normal vision. Photo reproduced with permission.

Figure 7

Recurrent irradiated basalioma involving the skull base, the orbit, and surrounding skin. (A) Preoperative illustration showing the extensive ulceration. (B) Intraoperative situation following radical tumor resection and orbital exenteration. A latissimus dorsi musculocutaneous free flap is already anastomosed to the superior thyroid artery. Microsurgery performed by A. Banic, Plastic & Reconstructive Surgery. (C) The patient's postoperative appearance with no further prosthetic rehabilitation. Photo reproduced with permission.

Figure 8

Patient with adenocarcinoma involving the right eye and skull base. (A) Preoperative view. (B) One year after orbital exenteration and reconstruction. The scapular fasciocutaneous flap is completely healed. Microsurgery performed by A. Banic, Plastic & Reconstructive Surgery. (C) Situation following flap debulking and epithetic rehabilitation by means of a silicone skin adhesive (Felber MA, Lucerne, Switzerland). Photos reproduced with permission.

Figure 9

Young woman with active fronto-orbital fibrous dysplasia and consecutive visual disturbancy. (A) Intraoperative view of the frontopterional craniectomy defect. O, orbital content; C, craniotomy defects with exposed dura. (B) On the basis of a sterolithographic model, a hydroxyapatite cement (BoneSource^®) template was preshaped, exactly placed, and fixed with a titanium mesh. (C) Preoperative CT scan illustrates the orbital restriction, left. Postoperative CT scan shows accuracy of the hydroxyapatite template, right. (D) Preoperative view with orbital depression, left. Same patient 1 year later with orbital symmetry and normal vision, right. Photos reproduced with permission.

Figure 10

Representative case with recurrent meningioma of the transitorial type. (A) Axial and sagittal MRI depict tumor involvement of the frontal sinus and frontal bone. (B) Intraoperative view of the craniectomy defect and resected dura. FS, frontal sinus. (C) Dural repair with fascia lata and fleece-bounded tissue sealing (TachoSil^®). Frontonasal duct closed with muscle and fascia. (D) Following obliteration of the frontal sinus with hydroxyapatite cement (BoneSource^®), a titanium mesh is adapted (see text). (E) Hydroxyapatite cement allows easy contouring of the supraorbital region and orbital roof. (F) Frontal and lateral 3-D CT scans show the exact shape of the reconstructed fronto-oirbital region, left. Patient's postoperative appearance, right. Photo reproduced with permission.

Figure 11

Necrosis and resorption of the frontonasal segment 1 year after successful removal of a juvenile ossifying fibroma of the skull base. (A) Collapse of the nasal dorsum. G, glabela. (B) Reconstruction with calvarial bone grafts, long miniplate, and nasal dorsum onlay graft. (C) Frontal pre- and postoperative view. (D) Same patient's lateral pre- and postoperative appearance. Photos reproduced with permission.