Large Skull Base Defects Research Articles

Endoscopic repair of large skull base defects after powered sinus surgery

Objectives To evaluate the management of patients with large skull base defects (> 2 cm) and intracranial injury caused by powered endoscopic sinus surgery. Study design and setting All patients treated for postendoscopic sinus surgery skull base injury over a 4-year period were reviewed. Results Three patients with skull base defects greater than 2 cm in size and associated intracranial injury from powered ESS were identified. All patients presented with active cerebrospinal fluid leaks. CT scans showed intracranial injury and pathology reports revealed brain tissue removal. Using image-guided endoscopic techniques, all defects were addressed with multilayer repair. Closure was achieved in all patients on the first attempt, with an average follow-up of 27 months. Conclusions The use of powered instrumentation along the skull base can be dangerous and can result in extensive skull base defects with associated loss of dura and gray matter. Large ethmoid roof defects and significant intracranial injury, however, are not absolute contraindications to endoscopic repair.

Cranial Bone Grafts in Cerebrospinal Fluid Leak and Encephalocele Repair: A Preliminary Report

With the introduction and subsequent widespread acceptance of endoscopic surgery, otolaryngologists are increasingly being called on to care for patients with cerebrospinal fluid rhinorrhea and meningoencephaloceles. Patients with large encephaloceles and skull base defects present a special challenge. We present our experience with cranial bone grafts in treating this important entity. Our clinical experience was reviewed from 1998 to 2001. Review parameters included defect size, cranial bone graft harvest site and size, and graft appearance on postoperative follow-up. Results revealed that 20 patients underwent defect repair with cranial bone graft. The average defect was approximately 0.92 x 0.7 cm; nine defects were located in the ethmoid roof, eight defects were in the sphenoid, and three defects were in the posterior table of the frontal sinus. Donor sites included 2 parietal, 3 frontal, and 15 temporal (mastoid). Grafts healed well and all defects remained closed on endoscopic and computerized tomographic follow-up. All donor sites healed well. Our experience indicates that cranial bone graft is an excellent material for endoscopic reconstruction of skull base defects. It confers special advantages in large defects, in defects with complex three-dimensional characteristics, and in patients with cerebrospinal fluid leaks associated with an elevated intracranial pressure.

Reconstruction of Complicated Skull Base Defects Utilizing Free Tissue Transfer

We managed five patients with large skull base defects complicated by complex infections with microvascular free tissue transfer. The first patient developed an infection, cerebrospinal fluid (CSF) leak, and meningitis after undergoing a translabyrinthine resection of an acoustic neuroma. The second patient had a history of a gunshot wound to the temporal bone, with a large defect and an infected cholesteatoma that caused several episodes of meningitis. The third through the fifth patients had persistent CSF leakage and infection refractory to conventional therapy. In all cases prior attempts of closure with fat grafts or regional flaps had failed. Rectus abdominis myofascial free flap, radial forearm free flap or a gracilis muscle free flap was used after debridement of the infected cavities. The CSF leaks, local infections, and meningitis were controlled within a week. In our experience, microvascular free tissue provides the necessary bulk of viable, well-vascularized tissue, which not only assures a mechanical seal but also helps clear the local infection.

Complication avoidance in the treatment of malignant tumors of the skull base

The treatment of malignant skull base tumors has improved with the development of skull base surgical approaches that allow en bloc resection of a lesion and increase the efficacy of adjuvant therapies. The anatomical complexity of these lesions and their surroundings has led to a relatively high complication rate. Infection and cerebrospinal fluid fistulas are the most common serious procedure-related complications. They result from the frequent necessity of working in a contaminated space such as the paranasal sinuses as well as from the creation of large dural and skull base defects. The authors have reviewed the literature regarding complications of surgery for malignant skull base lesions and present several techniques and strategies for minimizing their incidence by performing the craniofacial approach to anterior skull base lesions.

Skull base reconstruction after anterior subcranial tumor resection

The goal of this study was to demonstrate the efficacy of a simple and reliable technique for anterior skull base and craniofacial reconstruction in patients who have undergone excision of tumors via the subcranial approach. There were 63 patients who had undergone 71 anterior skull base resections of tumors via the aforementioned approach. Twenty-nine cases (41%) involved malignant tumors and 42 (59%) involved benign tumors. Reconstruction of the anterior skull base was performed by a single team who used double-layer fascial graft. Limited dural defects were reconstructed using the temporalis fascia, whereas large anterior skull base defects were reconstructed using a fascia lata sheath. Reconstruction was achieved without the support of bone graft or titanium mesh and without pericranial, galeal, or free flaps. Pericranial flap wrapping of the frontonasoorbital segment was performed to prevent osteoradionecrosis if postoperative radiotherapy was planned. The incidence of cerebrospinal fluid (CSF) leakage, intracranial infection, and tension pneumocephalus was 5.6%. Histopathological examination of fascia lata grafts obtained in patients who had undergone a second procedure demonstrated integration of vascularized fibrous tissue to the graft, as well as local proliferation of a newly formed vascular layer embedding the fascial sheath. The use of a double-layer fascial graft alone was adequate for prevention of CSF leakage, meningitis, tension pneumocephalus, and brain herniation. The double-layer fascial flap provided a simple and reliable means for anterior skull base reconstruction after en bloc resection of both malignant and benign tumors.

Three-layer reconstruction for large defects of the anterior skull base.

To evaluate and discuss a three-layer rigid reconstruction technique for large anterior skull base defects. Prospective, nonrandomized, non-blinded. Tertiary teaching medical center. Twenty consecutive patients underwent craniofacial resection for a variety of pathology. All patients had large anterior cranial base defects involving the cribriform plate, fovea ethmoidalis, and medial portion of the roof of the orbit at least on one side. A few patients had more extensive defects involving both roof of the orbits, planum sphenoidale, and bones of the upper third of the face. The defects were reconstructed with a three-layer technique. A watertight seal was obtained with a pericranial flap separating the neurocranium from the viscerocranium. Rigid support was provided by bone grafts fixed to a titanium mesh, anchored laterally to the orbital roofs. All patients had a computed tomography scan of the skull on the first or second postoperative day. Patients were observed for immediate and long-term postoperative complications after such reconstruction. Postoperative computed tomography scans showed small pneumocephalus in all patients. It resolved spontaneously and did not produce neurologic deficits in any patient. There was no cerebrospinal fluid leak, hematoma, or infection. On long-term follow-up, exposures of bone graft or mesh, brain herniation, or transmission of brain pulsation to the eyes were not observed in any patient. Three-layer reconstruction using bone grafts, titanium mesh, and pericranial flap provides an alternative technique for repair of large anterior cranial base defects. It is safe and effective, and provides rigid protection to the brain.

Use of titanium mesh for reconstruction of large anterior cranial base defects.

The authors evaluated the role of titanium mesh used in combination with vascularized pericranium to provide rigid support during reconstruction of anterior skull base defects. Thirteen patients with large anterior skull base defects caused by tumor invasion or traumatic injury involving the cribriform plate, orbital roof, and planum sphenoidale were included in the study. The reconstruction technique involved placement of titanium mesh between two layers of continuous vascularized pericranium. Surgical glue and routine lumbar cerebrospinal fluid (CSF) drainage were not used in any patient. At a mean postoperative follow-up time of 22 months (range 8-39 months), none of the patients had developed infection or meningocele. Postoperative CSF rhinorrhea occurred in two patients with extensive dural defects, which resolved with temporary lumbar drainage. Use of titanium mesh and a two-layer vascularized pericranial graft is a safe, reproducible, and feasible method for reconstructing the anterior skull base. Patients with large dural defects may need temporary CSF diversion to avoid postoperative fistula formation.

Surgical treatment of a massive chondrosarcoma in the skull base associated with Maffucci’s syndrome: a case report

BACKGROUND A successfully treated massive chondrosarcoma in the skull base associated with Maffucci’s syndrome is presented. The purpose of this report is to discuss the surgical approach to the tumor and reconstruction of the skull base. CASE DESCRIPTION A 36-year-old woman who had a history of multiple enchondromas and subcutaneous hemangiomas presented with decreased right visual acuity and left papilledema. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a mass in the skull base. The tumor occupied the nasal and paranasal cavities, and extended to the anterior, middle, and posterior intracranial spaces. The midline skull base structures and the left middle cranial base were destroyed. Using a combined anterior craniofacial and left orbitozygomatic approach, the tumor was totally resected. The large skull base defect was reconstructed with a vascularized outer table parietal bone graft attached to a bipedicled temporoparietal galeal flap. The postoperative course was uneventful except for decreased left visual acuity, and temporary diplopia and facial hypesthesia. In 40 months of follow-up there was no recurrence. CONCLUSIONS A skull base approach should be selected to perform total resection of an extensive skull base tumor. The bipedicled temporoparietal galeal flap and vascularized calvarial bone was useful for simultaneous reconstruction.

Microvascular reconstruction of the skull base: Indications and procedures

Purpose: The aim of the current study was to review the use of free tissue transfer for reconstruction of the skull base and for coverage of intracranial contents. Patients and Methods: From 1990 until 1996, revascularized flaps were transferred to the skull and the skull base in 11 patients in whom intracranial/extracranial resection of tumors of the skull base was performed in cooperation with the Department of Neurosurgery. The defects resulted from removal of squamous cell carcinomas (n = 4), basal cell carcinomas (n = 4), malignant melanoma, malignant schwannoma, and malignant meningioma. Defect repair was accomplished by revascularized transfer of latissimus dorsi muscle flaps in seven cases and rectus abdominis flaps and forearm flaps in two cases each. In five patients with extensive intracranial tumor spread, reconstruction was performed for palliative reasons. Results: A safe soft tissue closure of the intracranial and intradural space was achieved in all patients, whereas the contour of the facial skull and the neurocranium was satisfactorily restored at the same time. By using the entire length of the grafted muscle, the vascular pedicle could be positioned next to the external carotid artery and conveniently connected to the cervical vessels. The mean survival time of the patients with palliative treatment was 8.4 months, with an average duration of hospital stay of 24.5 days. Conclusions: Despite the increased surgical effort of revascularized tissue transfer, microvascular reconstruction of large skull base defects appears to be justified, even as a palliative measure.

Microvascular reconstruction of the skull base—Indications and procedures

Abstract Purpose: The aim of the current study was to review the use of free tissue transfer for reconstruction of the skull base and for coverage of intracranial contents. Patients and Methods: From 1990 until 1996, revascularized flaps were transferred to the skull and the skull base in 11 patients in whom intracranial/extracranial resection of tumors of the skull base was performed in cooperation with the Department of Neurosurgery. The defects resulted from removal of squamous cell carcinomas (n = 4), basal cell carcinomas (n = 4), malignant melanoma, malignant schwannoma, and malignant meningioma. Defect repair was accomplished by revascularized transfer of latissimus dorsi muscle flaps in seven cases and rectus abdominis flaps and forearm flaps in two cases each. In five patients with extensive intracranial tumor spread, reconstruction was performed for palliative reasons. Results: A safe soft tissue closure of the intracranial and intradural space was achieved in all patients, whereas the contour of the facial skull and the neurocranium was satisfactorily restored at the same time. By using the entire length of the grafted muscle, the vascular pedicle could be positioned next to the external carotid artery and conveniently connected to the cervical vessels. The mean survival time of the patients with palliative treatment was 8.4 months, with an average duration of hospital stay of 24.5 days. Conclusions: Despite the increased surgical effort of revascularized tissue transfer, microvascular reconstruction of large skull base defects appears to be justified, even as a palliative measure.

Prediction of craniofacial growth

Transcranial masses in the infant population can leave considerable skull base defects following resection. Traditional reconstructive techniques can result in significant morbidity or poor cosmetic results. We present a case of a large skull base defect in a six week-old infant, after removal of a giant cranio-cervicofacial teratoma, which was reconstructed using a versatile submental island flap. Additionally, preoperative planning and intraoperative navigation was advanced with the use of a 3D constructed model of the patient's mass.