Variety Of Skull Base Lesions Research Articles

Endoscopic Endonasal Surgery for Uncommon Pathologies of the Sellar and Parasellar Regions.

Endoscopic skull base surgery has become an integral part of the present neurosurgical armamentarium. The pioneering efforts in which the purely endoscopic transsphenoidal approach was introduced have triggered a growing tide of using the endoscopic endonasal procedures for a large variety of skull base lesions. Because of their anatomical peculiarities, lesions of the sellar and parasellar regions lend themselves very well to the endoscopic endonasal approaches. Apart from the common pathological entities, many other less frequent pathologies are encountered in the sellar and parasellar area. In this chapter, we review the surgical technique of the endoscopic endonasal transsphenoidal approach and its extensions applied to a variety of rare and uncommon pathological entities involving the sella turcica and clivus. An overview of these pathological entities is also presented and exemplified.

The 3F (Fat, Flap, and Flash) Technique For Skull Base Reconstruction After Endoscopic Endonasal Suprasellar Approach

Endoscopic endonasal surgery is a rapidly evolving field that offers the possibility of treating a wide variety of skull base lesions. Reconstruction of the osteodural defect is of utmost importance, as an effective and watertight closure is mandatory. Over the years, various techniques and materials have been adopted in an effort of providing a resilient and reliable method of closure. We retrospectively analyzed data from a series of 25 patients who underwent skull base reconstruction according to a novel paradigm following endoscopic endonasal transtuberculum-transplanum approaches for tumor removal between June 2017 and June 2018. The 3F strategy involves autologous fat grafting, nasoseptal flap coverage, and flash mobilization out of the bed following the operation. The 3F technique achieved successful watertight closure in 24 of 25 cases (96%). One case of postoperative cerebrospinal fluid rhinorrhea developed on postoperative day 10, which did not require reoperation. No perioperative complications related to the 3F strategy (e.g., overpacking, infections, or hematomas) occurred. No donor graft site infections or hematomas developed. The 3F skull base reconstruction is a safe and effective method in achieving watertight closure after extended endoscopic endonasal approaches. Despite this study reporting a preliminary experience in a small series of patients, it seems that the 3F technique can be considered as a viable solution among the wide kaleidoscope of available skull base reconstruction methods.

Reconstructive outcome of intraoperative cerebrospinal fluid leak after endoscopic endonasal surgery for tumors involving skull base

Endoscopic transnasal surgery for tumors located at the base of the skull has a high incidence of postoperative cerebrospinal fluid (CSF) leaks. Here, we assessed the repair outcomes for high-flow CSF leaks based upon the tumor location, and analyzed the reasons for repair failure after transnasal endoscopic surgery solely for tumors involving the base of the skull. From Feb. 2009 to Dec. 2014 we performed endoscopic endonasal surgery for a variety of skull base lesions in 788 patients at our institution. Among them, 95 patients with intradural skull base tumors underwent endoscopic transnasal surgery. We performed surgical repairs with a multilayered nonvascularized construct (38 patients) and a vascularized pedicled nasoseptal flap construct combined with a fascia graft (57 patients). Overall, 14 of 95 patients (14.7%) who underwent endoscopic transnasal surgery for skull base tumors developed postoperative CSF leaks. The major causes of repair failure included graft disruption by a lack of counter-pressure in the multilayered non-vascularized technique, and inadequate drilling of the sphenoid bone, displacement of the flap due to pressure from CSF or gravity, or disruption of flap integrity in the vascularized pedicled flap technique. Logistic regression analysis revealed that there was no significant association between repair failure and age, sex, type of reconstructive method used, and primary tumor type (p>0.05). Reconstruction after endoscopic endonasal surgery remained challenging, especially for non-pituitary skull base tumors requiring intra-arachnoidal dissection. Recent advances in reconstructive techniques require the accumulation of experiences with sufficient dexterity to achieve an acceptable morbidity rate.

The use of a three-dimensional endoscope for different skull base tumors: results of a preliminary extended endonasal surgical series.

The evolution of skull base surgery over the past decade has been influenced by advancement in visualization technology. Recently, as a result of such improvements, three-dimensional (3-D) scopes have been widely used during endoscopic endonasal approaches. In the present study, we describe the use of 3-D stereoscopic endoscope for the treatment of a variety of skull base lesions. From January 2010 to June 2015, a 3-D endoscopic endonasal approach (4 and 4.9mm, 0°, and 30° rigid endoscopes) was performed in 70 patients with the following lesions: 42 large extrasellar pituitary macroadenomas, seven tuberculum sellae meningiomas, seven clivus chordomas, five craniopharyngiomas, three fibrous dysplasia of the clivus, three sinonasal malignancies, one orbital lymphangioma, one trigeminal neurinoma, one primary suprasellar lymphoma. Total tumor removal was obtained in 50 patients (71.4%) while in 14 (20%), subtotal removal was possible in six (8.6%) only partial removal was achieved. Overall complications included diabetes insipidus in eight patients (11.4%), hypopituitarism in seven patients (10%), CSF leak in five patients (7.1%), cranial nerve injury in two patients (2.8%), panhypopituitarism in two patients (2.8%), meningitis in one (1.4%) and one postoperative central retinal artery occlusion (1.4%). There was no mortality in the series. The mean follow-up time was 39months (range, 6-72 months). In our experience, the 3-D endoscope represents a critical development in visualization, thus enabling improved hand-eye coordination and depth perception, which are mandatory for the management of complex intradural neurovascular structures during tumor removal surgery.

Sinonasal Outcomes following Endoscopic Endonasal Resection of Anterior Skull Base Meningiomas: Surgical Experience and Outcome Evaluation

Introduction: Endoscopic endonasal techniques are increasingly common in a variety of skull base lesions. A major obstacle that remains to be addressed within the field is sinonasal symptomatology following endoscopic repair, with a paucity of literature describing such outcomes following resection of large anterior skull base (ASB) meningiomas. Herein, we describe our institutional experiences utilizing SNOT-22 scoring in a series of ASB meningiomas treated via an endoscopic endonasal approach.

Corridor-Based Endonasal Endoscopic Surgery for Pediatric Skull Base Pathology With Detailed Radioanatomic Measurements

Pediatric anatomy is more restricted, and the propagation of endonasal endoscopic approaches in the pediatric population has been limited. To demonstrate the feasibility of the endonasal endoscopic approach in a variety of age groups and to perform measurements of the corridors and spaces available for surgery as a guide for case selection. Only patients <18 years were included. The choice of operative corridor/approach is described in relation to pathological entity and location. Preoperative/postoperative visual fields and endocrine panels, extent of resection, as well as postoperative long-term complications are described. Prospective magnetic resonance image-based anatomic measurements of key distances were performed to determine age-dependent surgical indications and limitations. Forty purely endoscopic procedures were performed in 33 pediatric patients (5-18 years of age) harboring a variety of skull base lesions, from benign tumors to congenital malformations. For the 20 patients in whom gross total resection was the intended goal of surgery, gross total resection was attained in 15 (75%). There were 2 infections (5%) and no cerebrospinal fluid leaks. Significant improvement was shown in 58.3% of patients with visual deficits. Hormone overproduction resolved in 75% of patients, while preoperative hormone insufficiency only improved in 29.2%. Wider intercarotid distance at the superior clivus (P = .01) and shorter nare-dens working distance (P = .001) predicted improved outcomes and fewer postoperative complications. Endonasal endoscopic skull base approaches are viable in the pediatric population, they are not impeded by sphenoid sinus aeration, and they have minimal risk of cerebrospinal fluid leak and meningitis. Outcomes and complications can be predicted based on specific radio anatomical skull base measurements rather than age.

Editorial: Sphenoidal encephaloceles

Ogiwara and Morota present a case series of sphenoidal encephaloceles.2 This is an uncommon entity and the authors provide a well-illustrated article reviewing their outcomes and treatment strategies. In their series, lesions involving only the sphenoid were successfully treated via a transpalatal approach. In these cases the hard palate was partially removed and the sac was dissected free circumferentially and reduced. They note that in the largest of the sphenoidal defects it was not possible to free the most anterior aspect of the encephalocele, although the sac could be reduced successfully. The bone defect was repaired either with bone or titanium mesh. In contrast, the larger lesions involving the sphenoids and ethmoids were prone to recurrence when treated either by a transpalatal or transcranial approach. The authors point out that the transpalatal approach limits the ability to dissect free the anterior portion of the encephalocele and that the transcranial approach limits the ability to dissect free the posterior aspect. The combined approach was used to successfully treat a single large sphenoethmoidal lesion. This is an excellent illustration of the utility of combined approaches in complex skull base anomalies. I suspect that the use of an endoscopic endonasal approach would be beneficial in the treatment of these lesions. We have treated 2 children under the age of 4 years who had nasoethmoidal encephaloceles.1 In both cases, the sac could be circumferentially dissected free at the skull base and the sac completely reduced, with no recurrence at almost 3 years of follow-up. Based on our experience with a variety of skull base lesions in children as young as 24 months, I would expect that the sphenoethmoidal encephaloceles could be treated via an endonasal rather than a transcranial approach. Additionally, the endonasal approach would potentially eliminate the need for significant resection of the hard palate by providing the exposure necessary to dissect free the anterior edge of the encephalocele. In children younger than 12 months of age the transcranial approach may still be needed to treat the larger sphenoethmoidal lesions because the nares may be too small for adequate working space. (http://thejns.org/doi/abs/10.3171/2012.12.PEDS12454)

Endoscopic Endonasal Two-Hand Surgery for Midline Skull Base Tumors

Objective: The recent evolution of the endoscopic technique has widened indication of endonasal endoscopic surgery for a variety of skull base lesions. Although four-hand surgery is the style of the majority, two-hand (single surgeon) surgery is commonly performed in Japan. We demonstrate our method of the surgery and discuss its possible advantages and disadvantages.

Injectable hydroxyapatite cement patch as an on-lay graft for the sellar reconstructions following endoscopic endonasal approach

Skull base reconstruction after endoscopic endonasal resection of a variety of skull base lesions remains challenging because of some lethal complications such as cerebrospinal fluid (CSF) leaks. We investigated the outcomes of hydroxyapatite (HA) cement patch as on-lay graft for skull base defects following endoscopic endonasal approach (EEA). We analyzed 53 consecutive patients who underwent sellar reconstruction using HA cement following EEA at our institution between July 2009 and March 2011. Patients were composed of 23 men and 30 women with a mean age of 47 years, ranging from 10 to 72 years. Among these patients, 29 patients (54.7%) experienced intraoperative CSF leaks with high-output, 10 patients (18.9%) underwent CSF leaks with low output, and 14 patients (26.4%) experienced no intraoperative CSF leak. Mean follow-up period for clinical outcomes was 8.6 months (range, 3-22 months). We performed injectable HA patch as on-lay graft over fascia lata for the skull base defects. Routine lumbar CSF drainage was not performed postoperatively in any patients since the introduction of HA. During the follow-up period, three of 53 patients (5.6%) demonstrated meningitis associated with postoperative CSF leaks and underwent re-do reconstruction surgery. There was no allergic symptoms associated with HA cement. At an outpatient clinic, the defects were found to be covered with surrounding nasal mucosa at an average of 14 weeks (range, 3-28 weeks). The use of HA cement as an on-lay patch for the reconstruction of sellar defect demonstrated a low incidence of CSF leaks with minimal complications. HA cement may be an alternative option for repair of CSF leaks following EEA.

Pediatric anterior skull base tumors: Our experience and review of literature

Surgery for skull base lesions has advanced considerably in the past few years. The improvement in surgical results could be attributed to the availability of refined imaging modalities, modern technological advances and multidisciplinary team approach. In this report, we present our personal experience in the surgical management of 45 children with a variety of skull base lesions treated over 10 years. This article includes a retrospective analysis of the surgical approaches used and their results with a review of the literature.

A New Technique for CT/MR Fusion For Skull Base Imaging

This paper presents our initial experience utilizing a new technique which allows CT and MR image fusion in patients with skull base lesions. Eleven patients with a variety of skull base lesions underwent CT and MR imaging prior to surgery. Both sets of images were coregistered using customized software. The CT and MR data sets were then combined and viewed in a single interactive image formar using a high-speed graphic computing system. Image fusion allowed simultaneous visualization of the bony skull base anatomy (CT) and detailed soft tissue anatomy (MR) using a single image format. Combining both modalities was felt to provide a better assessment of the extent of lesions and improve understanding of their relationship to adjacent bony and neurovascular anatomy. Specifically, image fusion enhanced awareness of location of skill base lesions with respect to the cavernous sinuses. Gasserian ganglia, carotid arteries, and jugular foramina. For tumors arising within the internal auditory canal (IAC), fused images allowed better delineation of the lateral aspect of the lesion with respect to the fundus of the IAC. Thus, fusion of CT and MR studies provides a unique image format which has advantages over single modality display. We believe image fusion is beneficial for surgical planning and for treatment planning of complex skull base malignancies treated with radiotherapy.