Craniofacial approaches to tumors of the anterior skull base

Transfacial Exposures of the Anterior Skull Base and Cervical Spine: Straightforward "Line-of-Sight" Algorithm for Selection of Approach

ABSTRACT

Surgical treatment for tumors of the skull base remains gross total resection with microscopic negative margins. Sufficient surgical access is paramount to adequate treatment but must be balanced with patient morbidity and protection of vital neurovascular structures. While endoscopic surgery has made transfacial access less common, there are still indications for open transfacial exposure including tumors that involve facial soft tissues, the palate, anterolateral frontal sinus, dural involvement lateral to the mid-pupillary line, tumor recurrence/repeat resection, and/or lack of access to endoscopic equipment or expertise. The authors present a "line-of-sight" algorithm for selection of approach, discuss pre-operative planning, review selected clinical experiences, and discuss the role of microsurgery and prevention of complications.

Nasal meatus plasty: a contribution to plastic reconstruction of the nasal valve during midfacial degloving

Midfacial degloving is a proven method for easily accessing the midface, the nasal pyramid, the maxillary and ethmoidal sinuses, the orbits, as well as the anterior skull base. Indications for this method of access mainly include tumour resections in the area of the midface, the septum, the maxillary sinus, the paranasal to the sphenoidal sinus as well as the clivus. In addition, this method of access allows for the exposure of the bony structures of the midface in the event of extensive fractures. In general, this method of access combines an incision in the oral vestibule and circular incisions in the nasal vestibule area in order to release the nasal pyramid. After removing the facial wall of the maxillary sinus, extensive exposure of the surgical site is possible. One disadvantage of this method of access is the difficult reconstruction of the nasal valve area, which often leads to cicatricial stenoses and difficulties with breathing through the nose. Furthermore, wound healing problems and osteoradionecrosis in the area of the lateral margin of the anterior nasal aperture after replantation of the facial wall of the maxillary sinus have been described, because in this area sufficient soft tissue coverage cannot be ensured when a conventional technique is used. We describe a soft tissue flap pedicled in the cranial and caudal directions in the nasal valve area which makes both the reconstruction of the nasal vestibule and sufficient soft tissue coverage of the anterior nasal aperture possible.

Craniofacial approaches and reconstruction in skull base surgery: techniques for the oral and maxillofacial surgeon

Skull base surgery (SBS) is considered the standard of care in treating benign and malignant lesions of the cranial base. SBS is a multidisciplinary team approach used to treat these complex lesions that may have intracranial extension. SBS can be broken down into 3 steps. Transfacial access is performed, followed by resection with sound oncologic principles, and then reconstruction of the cranial base and facial structures. Functional and esthetic concerns must be addressed by the surgeons. Oral and maxillofacial surgeons frequently perform elective facial osteotomies and treat victims of cranial base trauma. These same principles can be applied to SBS as a part of the skull base team.

Endoscopic versus traditional craniofacial resection for patients with sinonasal tumors involving the anterior skull base

OBJECTIVES

With the advent of microdebriders and image guidance systems, endoscope-assisted surgery is now more widely used for the treatment of tumors involving the base of the skull. The aim of this study was to analyze the clinical features of tumors involving the anterior skull base and to evaluate the treatment outcomes according to the surgical approach, which included the traditional craniofacial resection (TCFR) and the endoscopic craniofacial resection with craniotomy (ECFR).

METHODS

Forty-six patients who underwent craniofacial resection from 1989 through 2006 at Seoul National University Hospital and Seoul National University Bundang Hospital were included in this study. Demographics, histology, surgical management, surgical outcomes, complications, and morbidity were analyzed.

RESULTS

The number of malignant and benign lesions was 40 and 6 cases respectively. The most common diagnosis was olfactory neuroblastoma occurring in 41% of the cases followed by squamous cell carcinoma and malignant melanoma. Thirty-six patients underwent TCFR, while ECFR was performed with or without adjunctive chemotherapy or radiotherapy in 10 patients. The overall five-year survival rate for patients with malignant tumors of the anterior skull base was 47.4%. Out of 19 patients with olfactory neuroblastomas, 10 patients had TCFR and six among them died of their disease. Nine patients underwent ECFR, and none of them died of their disease. The ECFR group had lower morbidity and cosmetic deformity than did the TCFR group.

CONCLUSION

The ECFR may be considered as an alternative option for the treatment of selected tumors with anterior skull base invasion. This approach offers the advantages of avoiding facial incisions with comparable treatment results.

Skull Base Tumors: A Comprehensive Review of Transfacial Swing Osteotomy Approaches

Numerous techniques have been proposed for the resection of skull base tumors, each one unique with regard to the region exposed and degree of technical complexity. This study describes the use of transfacial swing osteotomies in accessing lesions located at various levels of the cranial base. Eight patients who underwent transfacial swings for exposure and resection of cranial base lesions between 1996 and 2002 were studied. The mandible was the choice when wide exposure of nasopharyngeal and midline skull base tumors was necessary, especially when they involved the infratemporal fossa. The midfacial swing osteotomy was an option when access to the entire clivus was necessary. An orbital swing approach was used to access large orbital tumors lying inferior to the optic nerve and posterior to the globe, a region that is often difficult to visualize. Gross total tumor excision was possible in all patients. Six patients achieved disease control and two had recurrences. The complications of cerebrospinal fluid leak, infection, hematoma, or cranial nerve damage did not occur. After surgery, some patients experienced temporary symptoms caused by local swelling. The aesthetic result was considered good. Transfacial swing osteotomies provide a wide exposure to tumors that occur in the central skull base area. Excellent knowledge of the detailed anatomy of this region is paramount to the success of this surgery. The team concept is essential; it is built around the craniofacial surgeon and an experienced skull base neurosurgeon.

Adénocarcinomes de l’ethmoïde : expérience nantaise (80 cas)

OBJECTIVE

To present results of a retrospective analysis of eighty cases of ethmoid adenocarcinoma. Carcinologic and surgical results of anterior skull base resection via the transfacial approach are presented.

METHODS

Tumors were classified as 5% T1, 23% T2, 31% T3, 21% T4a and 20% T4b. Thirty-four patients were treated via a paralateronasal approach without skull base resection. Anterior skull bas resections were performed via the transfacial approach for 26 patients and by combined neurosurgical approach for 21.

RESULTS

Mean follow-up was 4.8 years. Survival rate was 63.4% at 5 years and 57.9% at 8 years. Forty-two patients were alive and disease-free at last follow-up. Three patients were alive with recurrence. The rate of local recurrence was 38.8%. Complications occurred in 20% of the patients who had a transfacial approach. Complications appeared to be less frequent than with the combined approach.

CONCLUSION

Prognosis is related to local control and could be improved by using skull base resection more systematically. In our experience this can be managed by a transfacial approach with similar carcinological results and less complications than the combined approach.

The skull base, paranasal sinuses, and related malignancies

Tumors of the anterior skull base most commonly originate from the nasal cavity and paranasal sinuses. Such early presenting signs and symptoms as nasal obstruction, epiphora, and epistaxis are frequently thought to have a benign pathology. Proptosis, vision changes, skin fixation, and cervical adenopathy are associated with advanced disease. Treatment of paranasal sinus tumors is complex, involving combined therapy and multidisciplinary teams. The particular method of treatment is determined by multiple factors, including tumor histopathology, age, health of the patient, and extent of disease. In the past several years, numerous approaches to the skull base have evolved, allowing otolaryngologists and head and neck surgeons to extend earlier operative indications and treat cancers that were previously deemed unresectable. This article reviews some of the current surgical and nonsurgical approaches to skull base tumors originating from the paranasal sinuses.

Management of malignant tumors of the anterior skull base: experience with 76 patients

As the management of anterior cranial fossa malignancies has undergone significant evolution, decreases in morbidity and mortality rates have occurred. In this article, the authors discuss the clinical presentation, neuroimaging findings, and management options for common anterior skull base malignancies. Also discussed are surgery-related indications and principles.