The Treatment Strategy for Skull Base Reconstruction for Anterior Cranial Fossa Intra- and Extracranial Tumors.

ABSTRACT: Anterior cranial fossa intra- and extracranial tumors arise from the anterior cranial fossa and invade the orbit and nose. Anterior cranial fossa tumor resection and skull base reconstruction are challenging for neurosurgeons due to the complex anatomy, leakage of cerebrospinal fluid, and critical neurovasculature involvement. The authors report a case series of cranio-orbital communicating tumors and cranionasal-orbital communicating tumors. All patients underwent a modified Derome approach or transfrontal basal approach, and all tumor resections were satisfactory. Skull base reconstruction for small defects (<1.5 cm) can be performed with autogenous fascia, muscle, and fat. Large defects (≥1.5 cm) require autogenous fascia, muscle, and fat combined with osseous reconstruction (autogenous bone, titanium mesh, and polyetheretherketone). The techniques and treatments were successful, and only 1 patient experienced mild cerebrospinal fluid leak but no intracranial infection, pneumocrania or intracranial hemorrhage. Additionally, long-term follow-up demonstrated that the outcomes remain favorable. According to a literature review, this technique might be an alternative strategy for treating anterior cranial fossa intra- and extracranial tumors, and better skull base reconstruction can prevent many postoperative complications.

Utility of calcium phosphate cement cranioplasty following supraorbital approach for tumor resection.

OBJECTIVE: We have previously documented the utility of calcium phosphate cement cranioplasty following retromastoid craniectomy. In this study, we aimed to demonstrate its efficacy following a supraorbital approach for tumor resection. METHODS: A retrospective analysis of a prospectively maintained database was conducted of eight patients (7 female, 1 male) with anterior cranial fossa meningiomas resected via a supraorbital approach followed by cranioplasty involving adjunctive or sole use of calcium phosphate cement. RESULTS: Cranioplasty was achieved in all patients. No patient developed an incisional leak. The cohort had a mean follow-up of approximately 3.1 months (range: 0.5-7 months) in which time no further complications were noted. No patients developed post-surgical infections. CONCLUSION: In our experience, a low incidence of infection or CSF leaks has been noted after the use of calcium phosphate cement retromastoid cranioplasty. Extending this technique to supraorbital craniotomies may minimize incisional CSF leak.

Osseous Repair in Minimally Invasive Reconstruction of Anterior Skull Base Defects.

Management of anterior skull base defects is an area of continued innovation for skull base surgeons. Various grafting materials have been advocated for the repair of skull base defects depending on needs, availability, harvest site morbidity, and surgeon preference. Spontaneous bony closure of small skull defects is known to occur in animal models without bone grafts, but this phenomenon has been unexplored in the human skull base. The objective of this study was to evaluate osseous skull base closure in patients undergoing endoscopic repair of skull base defects. A retrospective review was performed on 13 patients who underwent endoscopic repair of skull base defects with free bone grafts who were followed with postoperative computed tomography scans. This cohort was compared to postoperative radiology from patients undergoing transsphenoidal surgery without rigid reconstruction to evaluate for spontaneous osseous closure of sellar defects. Free bone grafts are incorporated into the bony skull base in the majority of patients (84.6% with at least partial incorporation) at mean of 5.3 years postoperatively. By comparison, patients undergoing pituitary surgery did not demonstrate spontaneous osseous closure on postoperative imaging. Human anterior skull base defects do not appear to spontaneously close, even when small, suggesting that there is no "critical size defect" in the human skull base, in contrast to the robust wound healing in animal models of skull convexity and mandibular defects. Free bone grafts incorporate into the skull base over the long-term and may be utilized whenever a rigid skull base reconstruction is desired, regardless of the defect size.

Microvascular Tissue Transfers for Midfacial and Anterior Cranial Base Reconstruction.

Reconstruction of a midfacial defect can represent a difficult challenge for the plastic surgeon. Although many midfacial deformities have traumatic or congenital origins, the vast majority of head and neck defects occur after resection of malignant head and neck neoplasms. Autogenous reconstruction is now routinely performed for larger, complex defects resulting from surgical resection or trauma. In this study, the authors present 27 patients with midfacial defects reconstructed with free flaps. Twenty-two of the defects were created by surgical ablation of cancer (maxillectomy) and the others were traumatic. The maxillectomy defects were classified into 4 according to the classification proposed by Cordeiro. Eighteen of the patients were male and 9 were female. Twenty-nine free flaps were performed. Six different types of flaps including radial forearm flap, vertical rectus abdominis (VRAM) flap, anterolateral thigh (ALT) flap, tensor fasciae latae (TFL) flap, fibula osteocutaneous flap, and iliac osteocutaneous flap were accomplished. Types I and II defects were reconstructed with radial forearm flap. Type III defects were reconstructed with VRAM and ALT. Type IV defects were reconstructed with VRAM and TFL. Two patients underwent a second flap reconstruction due to recurrent disease (9.1%). Average patient age was 53.1 years. Free-flap survival was 100%. Free tissue transfer is the method of choice in midfacial reconstruction. Following a reconstructive algorithm is useful in the decision-making process for patient evaluation and treatment. Every reconstructive microsurgeon might have different experiences with different flaps. Therefore, the algorithm for flap choices is not universal among surgeons.

Transarterial embolization of an anterior fossa cranial base dural arteriovenous fistula.

Open surgical disconnection has long been the treatment of choice for dural arteriovenous fistulas (dAVFs) of the anterior cranial fossa. However, advanced patient age and the presence of medical comorbidities can substantially increase the risk of craniotomy and favor a less invasive endovascular approach. Optimal positioning within the distal ophthalmic artery, beyond the origin of the central retinal branch, is achievable using current microcatheter technology and embolic materials. Here we present the case of an 88-year-old female with an incidentally discovered dAVF of the anterior cranial fossa. Angiographic cure was achieved with one-stage Onyx embolization. The video can be found here: http://youtu.be/KVE0fUIECQM .

[Transnasal endoscopic approaches to the cranial base]. / Przeznosowe dostepy chirurgiczne w endoskopowych operacjach podstawy czaszki.

Recent advances in surgical endoscopy have made it possible to reach nearly the whole cranial base through a transnasal approach. These 'expanded approaches' lead to the frontal sinuses, the cribriform plate and planum sphenoidale, the suprasellar space, the clivus, odontoid and atlas. By pointing the endoscope laterally, the surgeon can explore structures in the coronal plane such as the cavernous sinuses, the pyramid and Meckel cave, the sphenopalatine and subtemporal fossae, and even the middle fossa and the orbit. The authors of this contribution use most of these approaches in their endoscopic skull base surgery. The purpose of this contribution is to review the hitherto established endoscopic approaches to the skull base and to illustrate them with photographs obtained during self-performed procedures and/or cadaver studies.

Prosthodontic treatment and medical considerations for a patient with Turner syndrome: a clinical report.

This clinical report describes a multidisciplinary approach in the rehabilitation of a 23-year-old Caucasian woman affected with Turner's syndrome and subsequently diagnosed with T4 Giant cell reparative granuloma of the right maxillary sinus. The surgical treatment included a maxillectomy and infratemporal fossa dissection followed by a free fibula palatal reconstruction, fibula bone graft of the orbital floor, dental implant placement, and prosthodontic rehabilitation. Prosthodontic planning and treatment considerations in an adult patient with Turner Syndrome are discussed.

Ameloblastic fibrosarcoma involving the anterior and middle skull base with intradural extension.

Ameloblastic fibrosarcoma is a malignant odontogenic tumor that rarely affects the skull base and surrounding regions. We present a case of a 48-year-old man with histologically confirmed malignant transformation of a benign ameloblastic fibroma 10 years after initial presentation of a localized facial mass. The ameloblastic fibrosarcoma extended from the facial region to the orbit, anterior and middle fossa skull base, the infratemporal fossa, and the cavernous sinus. Progressive proptosis with complete monocular vision loss was the presenting symptom. To our review, our case represents the first report of intradural extension of ameloblastic fibrosarcoma. Using a multidisciplinary skull base approach, resection of all tumors except that in the cavernous sinus was achieved with the resulting defect reconstructed with an anterolateral thigh free flap. The patient had no new neurologic deficits after surgery and underwent adjuvant fractionated radiation therapy. Malignant transformation of ameloblastic fibroma into ameloblastic fibrosarcoma can occur many years after initial presentation. Thus, vigilant long-term follow-up is essential despite the benign nature of the initial pathologic lesion. Use of a multidisciplinary approach is critical in obtaining the optimal outcome in these complex cases.

Middle fossa approach for spontaneous cerebrospinal fluid fistula and encephaloceles.

PURPOSE OF REVIEW: The aim of this article is to describe the middle fossa craniotomy (MFC) approach for the repair of cerebrospinal (CSF) fistula and encephaloceles. RECENT FINDINGS: The MFC approach has a greater than 93% success rate for managing CSF fistula and encephaloceles located along the tegmen tympani and tegmen mastoideum. Posterior fossa defects cannot be managed by an MFC approach. Multilayer repair with the combination of soft tissue and durable substances is preferred. Hydroxyapatite bone cement provides a durable repair of thinned or absent areas of bone with a low risk of infection. Concurrent management of symptomatic superior semicircular canal dehiscence may be readily performed. Small keyhole craniotomies with the utilization of the endoscope are possible as a means to minimize temporal lobe retraction. SUMMARY: MFC repair of CSF fistula and encephaloceles is a highly effective approach for the repair of tegmen mastoideum and tegmen tympani defects.

Combined subcranial approaches for excision of complex anterior skull base tumors.

OBJECTIVE: To present our method for excision of complex anterior skull base tumors via combinations of the subcranial approach. PATIENTS: Of 120 anterior skull base tumor resections, 41 that included 27 (66%) malignant and 14 (34%) benign lesions were performed via combinations of the subcranial approach. Unilateral or bilateral medial maxillectomy was performed using the subcranial approach alone for 13 tumors infiltrating the anterior skull base, ethmoid bones, and medial maxillary wall. A combined subcranial-transfacial approach in 2 lesions or a combined subcranial-midfacial degloving approach in 14 lesions was performed for tumors involving the skull base and the lower or lateral segments of the maxilla. A combined subcranial-transorbital or transfacial-transorbital approach was used for 5 tumors invading the orbit. An extended subcranial-orbitozygomatic approach was used for 6 tumors invading the middle cranial fossa or involving the cavernous sinus. A combined subcranial-Le Fort I down-fracture approach was used for 1 dedifferentiated chordoma invading the anterior skull base and lower clivus. The surgical results, patient quality of life, survival, and complications were measured. RESULTS: Thirty-seven of 41 tumors (90%) were completely resected. Fifteen patients (35.5%) had perioperative complications. There were no postoperative deaths. Two-year overall and disease-free survival in patients with malignant tumors who underwent combined approaches was 66% and 60%, respectively. There was no significant difference in the quality of life between patients operated on via combined or classic subcranial approaches. CONCLUSION: Combinations and modifications of the subcranial approach for excision of complex anterior skull base tumors yield surgical results, survival, quality of life, and complications similar to those found with the classic subcranial technique.

Fronto-ethmoidal teratoma: case report.

A one-month old baby was referred to the neurosurgical unit, Kenyatta National Hospital, Nairobi, Kenya, with history of being born with a bony outgrowth from the right side of her face which resembled an undeveloped twin. A computerised tomography scan of the brain and the extracranial mass confirmed a defect in the anterior cranial fossa and extension of the mass intracranially. Total surgical excision of the mass was done and facial reconstruction achieved. Histology of the excised mass confirmed a mature (benign) teratoma. Except for location, fronto-ethmoidal teratoma resembles its counterpart in the sacro-coccygeal area. It may arise over the nasion, or within the nose, orbit, or mouth and frequently extends intracranially. Like other teratomatous tumours, malignant changes tend to occur with increasing age. Calcification within the mass is often evident on plain skull x-rays. Treatment consists of early total excision.

Embolization of dural arteriovenous fistula of the anterior cranial fossa through the middle meningeal artery with Onyx.

OBJECTIVE: Dural arteriovenous fistula (DAVF) of the anterior cranial fossa is usually treated by surgical disconnection or endovascular embolization via the ophthalmic artery. The middle meningeal artery is a rarely used approach. This study investigated the safety and efficacy of embolization of DAVF of the anterior cranial fossa with Onyx through the middle meningeal artery. METHODS: A retrospective review of a prospective cerebral vascular disease database was performed. Patients with DAVF of the anterior cranial fossa managed with embolization through the middle meningeal artery with Onyx were selected. Information on demography, symptoms and signs, angiographic examinations, interventional treatments, angiographic and clinical results, and follow-up was collected and analyzed. RESULTS: Five patients were included in this study, four of whom had hemorrhage. All fistulas were fed by the bilateral ethmoidal arteries arising from the ophthalmic artery and by the anterior branch of the middle meningeal artery. The abnormal shunt unilaterally drained into the superior sagittal sinus with interposition of the cortical veins all five patients. All endovascular treatments were successful with evidence of an angiographic cure. No complications occurred, and all patients recovered uneventfully without neurologic deficits. There were nearly no symptoms among the patients during follow-up. CONCLUSION: Embolization of DAVF of the anterior cranial fossa via the middle meningeal artery with Onyx is safe, effective, and a good choice for management of DAVF. More cases are needed to verify these findings.

The 1-piece transbasal approach: operative technique and anatomical study.

OBJECT: The transbasal approach (TBA) is an anterior skull base approach, which provides access to the anterior skull base, sellar-suprasellar region, and clivus. The TBA typically involves a bifrontal craniotomy with orbital bar and/or nasal bone osteotomies performed in 2 separate steps. The authors explored the feasibility of routinely performing this approach in 1 piece with a quantitative cadaveric anatomical study, and present an operative case example of their approach. METHODS: Seven latex-injected cadaveric heads underwent a 1-piece TBA, followed by additional bone removal typical for a traditional 2-piece approach. Six surgical angles relative to the pituitary stalk, as well as the surface area of the orbital roof osteotomy, were measured before and after additional bone removal. The vertical angle from the frontonasal suture to the foramen cecum was measured in all specimens. In addition to an anatomical study, the authors have used this technique in the operating room, and present an illustrative case of resection of an anterior skull base meningioma. RESULTS: Morphometric results were as follows: the vertical angle from the frontonasal suture to the foramen cecum ranged from 17.4° to 29.7° (mean 23.8° ± 4.8°) superiorly. Of the 6 surgical angle measures, only the middle horizontal angle was increased in the 2-piece versus the 1-piece approach (mean 43.4° ± 4.6° vs 43.0° ± 4.3°, respectively; p = 0.049), with a mean increase of 0.4°. The surface area of the orbital osteotomy was increased in the 2-piece versus the 1-piece approach (mean 2467 mm(2) ± 360 mm(2) vs 2045 mm(2) ± 352 mm(2), respectively; p < 0.001). The patient in the illustrative clinical case had a good outcome, both clinically and cosmetically. CONCLUSIONS: The 1-piece TBA provides an alternative to the traditional 2-piece approach. It allows easier reconstruction, potentially decreased operative time, and improved cosmesis. While more of the orbital roof can be removed with the 2-piece approach, this additional bone removal offers only a small increase in 1 of 6 surgical angles that were measured.

Spontaneous cerebrospinal fluid rhinorrhea secondary to anterior fossa osteoradionecrosis.

Osteoradionecrosis (ORN) after radiation therapy of head and neck or brain tumor most often presents in the mandible, followed by the maxillary bone. This case report describes a patient who presented with spontaneous cerebrospinal fluid (CSF) rhinorrhea 12 months after conventional external beam radiotherapy for frontotemporal anaplastic astrocytoma, and was diagnosed with anterior fossa ORN. Osteolysis in the anterior fossa on CT scan confirmed the diagnosis. A prompt temporal muscle graft with pericranial flap seal treated both the ORN and the CSF rhinorrhea, but observation would have been a suitable conservative option if ORN presented without CSF rhinorrhea.

Transcervical double mandibular osteotomy approach to the infratemporal fossa.

BACKGROUND: In this study, we propose an alternative to the traditional transmandibular lower lip and chin splitting approach for exposing high infratemporal fossa and parapharyngeal space lesions involving the carotid canal and jugular foramen. METHODS: We present 2 cases of high skull base tumors removed transcervically with anterior and posterior segmental mandibulotomies preserving the mental nerve without the use of a lip or chin incision. RESULTS: Making the posterior osteotomy in an inverted L configuration is necessary so that the coronoid process does not prevent rotation of the mandible out of the visual field. Both patients had complete tumor resection with access to the carotid canal and jugular foramen and functional preservation of the mental nerve and marginal branch of the facial nerve. Neither patient had malocclusion or other dental complications from the approach. CONCLUSIONS: This novel technique is useful for providing excellent access to high infratemporal fossa or parapharyngeal space tumors. It avoids the traditional chin or lip incision and preserves the mental and facial nerves and is a useful procedure in the armamentarium of skull base/cerebrovascular neurosurgeons.

Endoscopic anterior maxillotomy: infratemporal fossa via transnasal approach.

OBJECTIVES/HYPOTHESIS: To evaluate our initial experience with a novel technique, endoscopic anterior maxillotomy (EAM), for improved access to the anterior-lateral skull base. Clinical and radioanatomic data are presented to describe and define this novel technique. STUDY DESIGN: Case series. METHODS: Surgical patients with lesions of the pterygopalatine fossa, infratemporal fossa, and anterior-lateral maxilla treated from 2006 to 2008 are reviewed. Demographic data and surgical technique are presented. A radioanatomic analysis pre- and post-EAM is performed to describe increased access. Matched-paired analysis was performed for statistical evaluation. RESULTS: Thirty-two patients had surgical treatment of anterior-lateral skull base lesions. EAM was utilized in 16 cases. Fifty-six percent extended lateral to V2 and 56% extended posterior to the maxillary sinus. Complete resection was achieved in 11 patients. There was one unplanned subtotal resection. Radioanatomic measurements demonstrated an increase in the radius of surgical access to the ipsilateral skull base using the EAM when compared with both standard transnasal techniques (33.1° vs. 14.8°; P < .0001) and extended approaches removing the nasolacrimal duct (33.1° vs. 23.5°; P < .001). Similar findings were noted for lateral access to the contralateral skull base. CONCLUSIONS: Endoscopic anterior maxillotomy is a novel technical addition to the skull base surgeon's armamentarium. Radioanatomic analysis demonstrates a significant improvement in access to the anterolateral skull base.

Craniofacial approaches to large juvenile angiofibromas.

OBJECT: Craniofacial approaches provide excellent exposure to lesions in the anterior and middle cranial fossae. The authors review their experience with craniofacial approaches for resection of large juvenile nasopharyngeal angiofibromas. METHODS: Between 1992 and 2009, 22 patients (all male, mean age 15 years, range 9-27 years) underwent 30 procedures. These cases were reviewed retrospectively. RESULTS: Gross-total resection of 17 (77%) of the 22 lesions was achieved. The average duration of hospitalization was 8.2 days (range 3-20 days). The rate of recurrence and/or progression was 4 (18%) of 22, with recurrences occurring a mean of 21 months after the first resection. All patients underwent preoperative embolization. Nine patients (41%) developed complications, the most common of which was CSF leakage (23%). The average follow-up was 27.7 months (range 2-144 months). The surgery-related mortality rate was 0%. Based on their mean preoperative (90) and postoperative (90) Karnofsky Performance Scale scores, 100% of patients improved or remained the same. CONCLUSIONS: The authors' experience shows that craniofacial approaches provide an excellent avenue for the resection of large juvenile nasopharyngeal angiofibromas, with acceptable rates of morbidity and no deaths.

High-viscosity polymethylmethacrylate cement for endoscopic anterior cranial base reconstruction.

Endoscopic endonasal transsphenoidal surgery (ETSS) is an effective, minimally invasive approach for the resection of anterior skull base tumors. Cerebrospinal leakage is a common complication, and repair of the anterior skull base defect with alloplastic materials has been used to minimize the risk of postoperative CSF rhinorrhea and meningitis. Injectable cements, such as low-viscosity polymethylmethacrylate (PMMA), are useful for cranial base reconstruction because they are easy to shape to the contour of the defect. These low-viscosity materials, however, are more susceptible to leakage into the nasal cavity prohibiting their use and are prone to cracking upon hardening. Cement extravasation not only obstructs the operator's view during placement, but it is also associated with significant local and systemic complications. High-viscosity (HV) PMMA-based cement and its specialized delivery system have recently been shown to be safe and effective in human applications. Moreover, its constant high viscosity significantly reduces cement leakage and its associated complications. The authors hypothesized that this type of cement would therefore be ideal for ETSS to repair anterior skull base defects. The authors report their experience using HV-PMMA to reconstruct the anterior skull base in 12 patients following ETSS. The unique puttylike consistency of this material is easy to work, malleable, does not leak into the nasal cavity, does not aspirate into suction tubing, and hardens without cracks in less than 10 minutes. None of the 12 patients suffered postoperative CSF leaks or infections more than 8 months, on average, after surgery. Although not necessary in all cases of ETSS, the authors conclude that HV-PMMA, if needed, may be an excellent choice for reconstructing the anterior skull base after ETSS. Further studies are needed to better assess the long-term outcomes of HV-PMMA cement and its use in repairing skull base defects after extended ETSS.

Withstand pressure of a simple fibrin glue sealant: experimental study of mimicked sellar reconstruction in extended transsphenoidal surgery.

BACKGROUND: To examine the strength and tolerance of the fibrin glue sealant in a situation of extended transsphenoidal surgery. The withstand pressure of fibrin glue sealant was measured using a simple sellar reconstruction model. METHODS: A 15-mm diameter hole at the bottom of a 51-cm high cylinder was covered with a Gore-Tex (Gore-Tex, Tokyo, Japan) sheet. A small plate was placed on the center for a brief fixation, and 3 mL of fibrin glue was applied over the entire bottom. Then water was gradually filled in five cylinders, and the water level at leakage was measured as withstand pressures at 10 minutes and 24 hours after sealant application. The stability of the sealant under pressures of 20 and 30 cm H(2)O for 12 hours was also examined. RESULTS: The median initial withstand pressure at 10 minutes was 32 cm H(2)O (n = 5), and was significantly increased to 47.5 cm H(2)O after 24 hours (n = 4). In four of five cylinders, fibrin glue sealants were stable against a pressure of 20 cm H(2)O for 12 hours and 30 cm H(2)O for the next 12 hours. CONCLUSIONS: The withstand pressure of simple fibrin glue sealant without other biological reactions could be estimated to be more than 20 cm H(2)O after application, and increased to more than 40 cm H(2)O after 24 hours. These data are practical for neurosurgeons to comprehend the strength and limit of fibrin glue sealant and suggests the importance to control the intracranial pressure to less than 20 cm H(2)O, especially for the first 12 to 24 hours.