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

Abstract

Surgical approaches to the anterior cranial base have changed considerably with the introduction of endonasal endoscopic surgery. This study aims to define the factors which help in selecting the optimal surgical approach for the treatment of anterior cranial base encephaloceles. Patients who received treatment for anterior cranial base encephaloceles at our department between 1996 and 2011 were included in the study. Patients' charts were reviewed retrospectively to collect the necessary data. Treatment periods were classified as before 2000, between 2000 and 2005, and after 2005. The relationship between the treatment period, localization of encephalocele, symptoms related with the lesion, size of skull base defect, and selected treatment modality were investigated. Twenty-five patients, aged between 1 and 61 years with anterior encephaloceles were included in the study. Patients with small asymptomatic frontonasal and trans-ethmoidal encephaloceles (n = 5) were followed without surgery. An external approach with or without subfrontal craniotomy was mainly preferred for resection of sincipital encephaloceles (n = 10), especially with facial deformity. A subfrontal craniotomy approach was used for resection of basal encephaloceles in two cases before 2000. Two cases with sincipital encephaloceles and six cases with basal encephaloceles underwent pure endonasal endoscopic surgery after 2000. Cranial base defects of every size could be repaired using the endoscopic approach. Hydrocephalus and meningitis were the two complications seen after craniotomy in a follow-up period of 13-26 (mean 14.5) months. An external approach with or without craniotomy is needed for encephaloceles with external mass and facial deformity. Otherwise, sincipital and basal encephaloceles can be repaired successfully using the endonasal endoscopic approach.

Complications of Skull Base Surgery

“…These manifest as intranasal masses with CSF leakage. 18 Whether a meningoencephalocele is congenital or acquired, excision of the intranasal aspect of the lesion followed by a watertight closure of the skull base defect is the recommended treatment. This can be performed through an endonasal, endoscopic approach or via a craniotomy.…”

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

“…A more rigid reconstruction may also be helpful to prevent inadvertent intracranial injury secondary to nasogastric tube placement, positive air pressure, nasal packing, or any procedure performed through the nasal cavity. Rigid construction would prevent the potential complications of sag, ascending meningitis, CSF leak …”

“…Rigid construction would prevent the potential complications of sag, ascending meningitis, CSF leak. 14 The use of a bone graft in reconstruction prior to chemotherapy and radiation does pose a potential risk for osteonecrosis of the graft. The use of vascularized bone grafts has been recommended to minimize this risk, as has the use of vascularized flaps in general to improve the tolerance of the native bone to further treatments.…”

“…This was first described in 2009 . Both of these methods, however, result in nonrigid fixation and are theoretically subject to variable degrees of sag …”

“…13 Both of these methods, however, result in nonrigid fixation and are theoretically subject to variable degrees of sag. 14 The advantages of rigid reconstruction in the skull base are well illustrated by the gasket seal technique. Rates of initial and long-term cerebrospinal fluid (CSF) leak fall within the target of 5%, and reconstruction remains stable without the use of an endonasal buttress at the time of reconstruction.…”