Predictors of surgical approaches for the repair of anterior cranial base encephaloceles

Endoscopic endonasal repair of a temporal lobe meningoencephalocele in the pterygoid fossa: A case report and literature review

Introduction

Meningoceles are defined as herniation of the meninges through a skull base defect. If brain tissue is herniated as well, then it is called meningoencephalocele. The most common locations of meningoceles are the cribriform plate and the lateral recess of the sphenoid sinus, with the most common presentation being CSF leakage. We present a case of temporal lobe meningocele that herniated through a defect in the greater wing of the sphenoid bone to the pterygoid fossa and that was diagnosed incidentally while evaluating the patient for seizures.

Methodology

Case report and literature review.

Conclusion

The endonasal endoscopic approach is a suitable minimally invasive approach for the management of pterygoid fossa lesions, including meningoceles. In this case, the patient had epilepsy with the surgery resulting in the resolution of the seizures.

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Endonasal approach can be considered as a minimally invasive approach for lesions in the pterygoid fossa.

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Meningocele are to be considered as a possible etiology for pterygoid fossa masses connected with the middle cranial fossa.

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Surgical resection of encephalomeningocele should be considered for the management of intractable seizures.

Management of anterior fossa cephaloceles

Skull base cephaloceles (SBCs) are defined as herniation of intracranial content through the skull base and are classified based on composition, etiology, and topographic location. Anterior SBCs frequently protrude in the sinonasal cavity, and consequently are at potential risk of infection. Therefore, the current recommendation is to treat SBCs with the primary intent of preventing meningitis, and surgery represents the mainstay of treatment. Anterior SBCs may display a wide spectrum of severity and complexity, and in each case the risks and benefits of surgical approaches are to be carefully weighted based on thorough assessment of symptoms, age, general conditions, location and size of the lesion, as well as expertise of the surgeon. In the last 30 years, the evolution and diffusion of transnasal endoscopic surgery have substantially changed the surgical management of the majority of SBC. In the past, they were treated exclusively with open transcranial approaches that may be burdened by relevant morbidity and risk for severe complications. The transnasal endoscopic corridor now provides easy access to the lesion and different reconstructive strategies using endonasal pedicled flaps, without any external incision, cranioplasty or brain manipulation. However, there are still scenarios in which an exclusive transnasal endoscopic route is contraindicated. The aim of the present review was to provide an overview on the comprehensive management of anterior SBC, with a particular focus on lesions suitable for endoscopic surgery. Furthermore, special aspects of SBC management in children and adults will be highlighted.

Complications of Skull Base Surgery

Approaches to surgical management of skull base pathology and reconstruction of skull base defects have evolved over the past several decades. The goal, however, remains the same-to effectively address the pathology with minimal complications. In this article, the authors try to explore multiple complications of skull base surgery, discussing their incidence, natural course, and prevention. This will prove beneficial in optimal management of patients with a myriad of skull base disorders.

Endoscopic sinonasal meningoencephalocele repair: a 13-year experience with stratification by defect and reconstruction type

OBJECTIVE

Sinonasal meningoencephalocele is a rare defect, with varying etiologies and treatment strategies. Here we present the largest published series from a single institution of patients with endoscopic repair. The primary goal is to examine rates of success with consideration to accompanying patient demographic data. The secondary goal is to report the results stratified by defect and reconstruction type.

DESIGN

Retrospective consecutive case series.

SETTING

Tertiary care academic center.

SUBJECTS AND METHODS

Consecutive patients with CPT codes for skull base meningoencephalocele repair between May 2000 and March 2013 were reviewed. Patients who specifically had sinonasal defects were included.

RESULTS

During the study period, 149 cases of sinonasal meningoencephaloceles were managed in 133 patients. Mean follow-up was 21.3 months (range, 0-116). There was a success rate of 88% for initial repair, with mean recurrence time of 8.3 months (range, 0-38), and a success rate of 93.8% for initial recurrence surgery, with 99.3% of ultimate successful repair. All cases were repaired endoscopically. Recurrence rate was not significantly related to location of defect (P = .682), size of defect (P = .434), particular reconstruction technique (P = .163), or etiology (trauma, P = .070). Overall complication rate was 11.3%.

CONCLUSION

Endoscopic sinonasal meningoencephalocele repair has excellent long-term results and may be considered as a primary approach. Surgeon comfort with a particular technique should be the most important factor used to guide choice of reconstruction.

Surgical technique for repair of complex anterior skull base defects

Background:

Modern microsurgical techniques enable en bloc resection of complex skull base tumors. Anterior cranial base surgery, particularly, has been associated with a high rate of postoperative cerebrospinal fluid (CSF) leak, meningitis, intracranial abscess, and pneumocephalus. We introduce simple modifications to already existing surgical strategies designed to minimize the incidence of postoperative CSF leak and associated morbidity and mortality.

Methods:

Medical records from 1995 to 2013 were reviewed in accordance with the Institutional Review Board. We identified 21 patients who underwent operations for repair of large anterior skull base defects following removal of sinonasal or intracranial pathology using standard craniofacial procedures. Patient charts were screened for CSF leak, meningitis, or intracranial abscess formation.

Results:

A total of 15 male and 6 female patients with an age range of 26–89 years were included. All patients were managed with the same operative technique for reconstruction of the frontal dura and skull base defect. Spinal drainage was used intraoperatively in all cases but the lumbar drain was removed at the end of each case in all patients. Only one patient required re-operation for repair of persistent CSF leak. None of the patients developed meningitis or intracranial abscess. There were no perioperative mortalities. Median follow-up was 10 months.

Conclusion:

The layered reconstruction of large anterior cranial fossa defects resulted in postoperative CSF leak in only 5% of the patients and represents a simple and effective closure option for skull base surgeons.

Split-calvarial osteopericranial flap for reconstruction following endoscopic anterior resection of cranial base

OBJECTIVES/HYPOTHESIS

To conceive and critically evaluate an adaptation of the split calvarial osteopericranial flap for reconstruction following endoscopic endonasal resection of the anterior skull base.

STUDY DESIGN

Cadaveric anatomic study.

METHODS

Five cadavers were embalmed with methanol, and vasculature was injected with latex. Endoscopic endonasal resection of the anterior skull base was performed, followed by reconstruction with a unilateral osteopericranial flap and a contralateral conventional pericranial flap.

RESULTS

Rigid reconstruction was achieved in all specimens. Osteoplastic flap harvest was made more reliable by drilling the diploe below the graft with a curved bur. Dimensions of the bony flap were ideally shorter and wider than the defect, allowing for flap inset and rigid support by the orbits without compromise of the flap vascular supply. Endoscopic inset of the flap is feasible via nasion-frontal osteotomy and inlay technique.

CONCLUSION

Rigid anterior skull base reconstruction via split calvarial osteopericranial flap is adaptable to current endoscopic techniques. This provides more anatomic reconstruction than current methods and may lead to decreased complication rates following anterior skull base resection.