Mandibular access osteotomy: Gate way to parapharyngeal space – A case report

ABSTRACTBACKGROUND: Endoscopic transnasal surgery has gained rapid global acceptance over the last two decades. The growing literature and understanding of anterior skull base endoscopic anatomy, in addition to new dedicated endoscopic instruments and tools, have helped to expand the use of the transnasal route in skull base surgery.OBJECTIVE: Report our early experience in expanded endoscopic transnasal surgery (EETS) and approach to skull base neoplasms.DESIGN: Descriptive, retrospective case series.SETTING: Major tertiary care center.PATIENTS AND METHODS: A retrospective case review was conducted at King Saud University Medical City between December 2014 and August 2019. Cases with skull base neoplasms that underwent EETS were included. EETS was defined as endoscopic surgical exposure that extended beyond the sellar margins (prechiasmatic sulcus superiorly, clival recess inferiorly, cavernous carotid lines laterally). Routine transsphenoidal pituitary neoplasms, neoplasms of sinonasal origin and meningoencephaloceles were excluded.MAIN OUTCOME MEASURES: Preoperative clinical assessment, imaging results, surgical approach, and hospital course were all retrieved from the patient electronic charts. Clinical follow-up, perioperative complications, and gross residual tumor rates were documented and reviewed.SAMPLE SIZE AND CHARACTERISTICS: 45 cases of EETS, 13 males and 32 females with mean age of 39.0 (17.7) years (range 2–70 years).RESULTS: The series comprised a wide range of pathologies, including giant pituitary adenoma (8 cases), meningioma (23 cases), craniopharyngioma (4 cases), chordoma (4 cases), optic pathway glioma (2 cases), epidermoid neoplasms (2 cases), astrocytoma (1 case), and teratoma (1 case). For the entire series, gross total resection was achieved in 25/45 operations (55.5%). Postoperative cerebrospinal fluid leak was the most common complication observed in 9 patients (20%) which were all managed endoscopically. Major vascular complications occurred in 2 patients (4.4%) and are described. Other complications are outlined as well. No mortality was observed.CONCLUSIONS: EETS to the skull base can be done with results comparable to traditional approaches. More work is needed to expand our experience, improve outcomes, and educate the public and medical community in our region about the usefulness of this approach.LIMITATIONS: Sample size and study design.CONFLICT OF INTEREST: None.

<i>Background:</i> The management of tumors located at the skull base pose unique clinical challenges. Recent advances in cranial-based surgical approaches and radiation therapy, including stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT), have improved our ability to manage these complex tumors. Further study is required to evaluate the safety and efficacy of this technique. We present an evidence-based approach to FSRT for skull base tumors supported by analysis of the published literature. <i>Methods:</i> A comprehensive literature search was conducted from 1980 through December 2006. Patients with primary, residual or recurrent skull base lesions were included in this study. This database query identified 145 related publications. Based on inclusion criteria, 35 FSRT and skull base lesions related publications were identified between 2001 and 2006 by 28 different first authors in 21 different institutions. <i>Results:</i> A total of 1,582 patients with skull base lesions underwent FSRT, including cavernous sinus or other skull base meningiomas (776), schwannomas (208), pituitary adenomas (416), chordoma/chondrosarcoma (58), nasopharyngeal carcinoma (30), craniopharyngioma (71), cavernous hemangioma (1), and chemodectoma (22). Tumor control was 99% for meningiomas, 98% for schwannomas, 97% for pituitary adenomas, 79% for chordomas, 90% for nasopharyngeal carcinomas, 92% for craniopharyngiomas, 95% for cavernous sinus meningiomas, 91% for chemodectomas, and 100% for chondrosarcomas and cavernous hemangiomas. Toxicity was favorable, with 14% of patients developing alopecia, skin erythema, headaches, nausea, and vomiting. Only 0.8% developed late toxicity and were specific to sellar and parasellar tumors. <i>Conclusion:</i> With varying degrees of tumor control rate ranging from 79 to 100% in histologically different skull base tumors, 14% transient complications and 0.8% late toxicity, this analysis provides a framework within which risks and benefits of FSRT for skull base lesions should be considered in individual patients.

Utility of a rotation–suction microdebrider for tumor removal in endoscopic endonasal skull base surgery

SummaryA number of tumors and tumor-like non-neoplastic lesions with different cell types on histology occur in the skull base. A wide variety in disease and lesion appearance often complicates the process of radiological diagnosis. The main role of radiographic imaging is the detection and characterization of skull base lesions, with evaluation of the extent of invasion or preservation of adjacent critical organs. Evaluation of the skull base anatomy and surgical planning by using image guidance are also important for surgeons. Computed tomography (CT) and magnetic resonance (MR) imaging are the preferred modalities for the evaluation of skull base lesions. CT and MR are used for lesion detection, tissue characterization and assessment of neurovascular and bone involvement by the lesions. Both modalities provide useful information, one sometimes of greater value than the other. T1-weighted MR imaging is useful in detecting skull base lesions, typically surrounded by abundant fatty bone marrow. T2-weighted MR imaging is generally useful for tumor tissue characterization. CT surpasses MR imaging in evaluating intratumoral calcification and bone destruction or hyperostosis. To date, imaging features have been well-reported in individual skull base tumors; however, correct diagnosis by imaging alone still presents a challenge. Knowledge of clinical issues and awareness of variants of skull base tumors are of help in making a diagnosis. The purpose of this article is to review pertinent clinical issues, typical imaging appearances and certain imaging variations of common skull base lesions.

Pediatric sinonasal and skull base lesions are rare and complex disorders. The safe and comprehensive management of this diverse group of pathologies requires the expertise of an experienced multidisciplinary skull base team. With significant evolution and improved outcomes achieved in adult endoscopic skull base surgery (ESBS), similar principles have been applied to the pediatric population. Pediatric endoscopic surgery for sinonasal and skull base tumors has therefore also evolved due to a variety of technologic and surgical advances, multidisciplinary team approaches, and continued innovation. Pediatric sinonasal and skull base tumors require complex multidisciplinary management for optimal outcome. Detailed understanding of the sinonasal anatomy will improve surgical outcomes. The surgical approaches and techniques are dependent on the location of the lesion, the pathology, extent of disease, and surgical goals. Reconstruction following tumor extirpation follows the same principles as adult reconstruction, with the ultimate goal of achieving a watertight seal that separates the nasal cavity from the brain. Complications can be catastrophic and rely on immediate recognition and management to prevent long-term sequelae.

Techniques for skull base surgery have become well established over the last 10 years. Most of these techniques are used in adult patients for skull base tumors and neurovascular diseases. There are very few large series of pediatric patients in whom skull base approaches have been used, because of the rarity of these conditions. The authors would like to present a relatively large series of 26 pediatric patients who underwent skull base approaches for tumor resection. These tumors involved the anterior cranial base in 5 patients, the medial cranial skull base in 4 patients, and the posterior cranial base in 12 cases. Five patients had tumors that involved two or more fossae. The overall complication rate was 57%, which included temporary cranial nerve palsies, CSF leak and infection. Patients with permanent complications were 8 in number (37%). There was 1 postoperative death from pneumonia approximately 6 weeks after surgery. Complete tumor removal was achieved in 24 of the 26 patients. Skull base tumors in children are often extensive and present significant surgical challenges. Although complete tumor extirpation is the goal in most pediatric patients, this is often achieved only with some morbidity. This paper demonstrates the effectiveness of skull base approaches for these tumors and underscores the high stakes involved.

Smaller operative exposures, endoscopic approaches, and minimally invasive neurosurgery have emerged as a dominant trend in the modern era. In keeping with this evolution, the authors have recently eliminated the use of fixed retractors, instead employing dynamic retraction, with the use of handheld instruments. In the present study, the authors report the results of applying this strategy to challenging vascular and skull base lesions. This 6-month study prospectively analyzed the use of retractorless surgery in a consecutive series of 223 patients with intracranial vascular or skull base lesions undergoing craniotomy. A single surgeon performed all operations. The microsurgical approaches (in descending order of frequency) included an orbitozygomatic craniotomy (77 patients [35%]), frontal (36 patients [16%]), retrosigmoid (27 patients [12%]), interhemispheric (16 patients [7%]), and lateral supracerebellar (15 patients [7%]). The most common lesions were aneurysms (83 lesions overall [37%]), 18 of which required a bypass. Of 159 vascular lesions, there were also 46 cavernous malformations (29%). Meningiomas were the most common skull base tumors (37 cases [58%]). Of the 223 patients, 7 cases of various vascular and skull base lesions required fixed retraction. Therefore, 97% of the cases were successfully treated without a self-retaining retractor system. Fixed retraction can be supplanted by dynamic retraction with surgical instruments, limiting the risk of retractor-induced tissue edema and injury. This quiet revolution has precipitated a major change in surgical techniques. Extensive dissection of arachnoidal planes, careful placement of the handheld suction device, patient positioning that enhances gravity retraction, the refinement of microsurgical instrumentation, and appropriate selection of the operative corridor all serve to obviate the need for fixed retraction in most intracranial procedures. Retractorless neurosurgery is an achievable goal, even when complex lesions of the vasculature and skull base are being treated.

Here we describe the procedures of endoscopic pituitary and skull base surgery in our institute. We also review the literature to reveal recent advances in this field. Endonasal approach via the sphenoid ostium was carried out for pituitary lesions without the nasal speculum. Postoperative nasal packing was basically not needed in such cases. For meningiomas, craniopharyngiomas, and giant pituitary adenomas, which required intra-dural procedures, nasal procedures such as middle nasal conchotomy and posterior ethmoidectomy, and skull base techniques such as optic canal decompression and removal of the planum sphenoidale were carried out to gain a wider operative field. Navigation and ultrasonic Doppler ultrasonography were essential. Angled endoscopes allowed more successful removal of tumors under direct visualization extending into the cavernous sinus and lower clivus. If cerebrospinal fluid (CSF) leakage occurred during operation, the dural opening was covered with a vascularized mucoseptal flap obtained from the nasal septum. Lumbar drainage system to prevent postoperative CSF rhinorrhea was frequently not required. Angled suction tips, single-shaft coagulation tools, and slim and longer holding forceps, all of which were newly designed for endoscopic surgery, were essential for smoother procedures. Endonasal endoscopic pituitary surgery allows less invasive transsphenoidal surgery since no postoperative nasal packing and less dependence on lumbar drainage are needed. Endoscopic pituitary surgery will be more common and become a standard procedure. Endoscopic skull base surgery has enabled more aggressive removal of extrasellar tumors with the aid of nasal and skull base techniques. Postoperative CSF leakage is now under control due to novel methods which have been proposed to close the dural defect in a water-tight manner. Endoscopic skull base surgery is more highly specialized, so needs special techniques and surgical training. Patient selection is also important, which needs collaboration with ear, nose, and throat specialists. As a safe and successful procedure in skull base surgery, this complex procedure should be carried out only in specialized hospitals, which deal with many patients with skull base lesions.

The object of the present paper is to compare pre- and postoperative facial nerve function results between unmonitored and monitored surgical cases of cerebellopontine angle and skull base lesions.

Meningiomas have diverse presentations and the skull base harbors the most difficult of them to operate upon. The objective of this study was to learn whether the recurrence and outcome of these tumors may differ based on their location. Consecutive admissions with intracranial meningiomas between 1999 and 2004 were considered according to their location, WHO grade, recurrence, and outcome following treatment. There were 83 skull base meningiomas and 86 at other locations. In 22 cases of skull base tumors there was recurrence (26.5%), while 15% (13) of the other group showed recurrence. There was no statistically significant difference in the outcome between the two groups; though skull base lesions had a better outcome based upon a raw count. Only 5.1% of skull base meningiomas in comparison to 10.6% of non-skull base meningiomas had death or significant morbidity. Increasing age was associated with poor outcome (p < 0.001) while recurrence was a function of skull base location (p < 0.03) on logistic regression analysis. Skull base meningiomas can be operated upon with good outcome, which is comparable to the convexity meningiomas. Except for the increasing age, skull base location does not contribute to increased mortality or morbidity.

Objective To evaluate the role of periodically rotated overlapping parallel lines enhanced reconstruction (PROPELLER) DWI in skull base.Methods Both PROPELLER and echo-planar imaging (EPI) DWI with b values of 500 and 1 000 s/mm2 in skull base were performed in 61 consecutive patients who had been examined with routine head and neck MRI because of symptoms of ear or nose or throat.All of 61 patients were divided into two groups:the normal group without lesion and the lesion group with lesions on MRI.The mean distortion scores and SNRs of structures in skull base with different DWI sequences (PROPELLER and EPI) and b values were compared by paired sample t test in each group.Moreover,the positive rates of PROPELLER DWI were contrasted with those of EPI DWI by paired data x2 test in the lesion group.Results The normal group included 16 patients,and the lesion group included 45 patients.With b values of 1 000 s/mm2,the mean distortion scores of EPI DWI and PROPELLER DWI in normal group were 1.34 ± 0.48,3.94 ± 0.25 respectively,and were 1.57 ± 0.54,3.94 ± 0.23 respectively in the lesion group.With b values of 500 s/mm2,the mean distortion scores of EPI DWI and PROPELLER DWI in nommal group were 1.38 ± 0.49,3.97 ± 0.18,respectively,and were 1.60 ± 0.54,3.97 ±0.18 respectively in the lesion group.There were significant difference in the mean distortion scores between EPI DWI and PROPELLER DWI with b values of 1 000 or 500 s/mm2 in both groups (with t values of-29.40,-40.84,-29.40,and-42.45 respectively,and P ＜0.01).With b value of 1 000 s/mm2,the mean SNRs of PROPELLER DWIs in all of the skull base structures except for cerebellar hemisphere and temporal pole were higher than those of EPI DWIs (P ＜ 0.05).Also,with b value of 500 s/mm2,the mean SNRs of PROPELLER DWIs in all of the skull base structures were higher than those of EPI DWIs except for eerebellar hemisphere,temporal pole and temporalis.Moreover,the positive rate of PROPELLER DWI (97.78％,44/45) in the lesion group with masses was significantly higher (x2 =16.317,P ＜ 0.01) than that of EPI DWI (64.44％,29/45).Conclusions PROPELLER technique can reduce or eliminate distortion and artifacts,increase the image quality and the positive rate of lesion on diffusion-weighted images.Therefore,PROPELLER DWI is regarded useful in the diagnoses and the evaluation of therapeutic effect in patients with lesions in skull base. Key words: Skull base; Magnetic resonance imaging; Image quality

Embolization is now recognized as an established endovascular interventional neuroradiologic technique for the preoperative devascularization of vascular neoplasms of the intracranial space and of the skull base (Lasjaunias and Berenstein 1987b; Valavanis 1990; Halbach et al. 1992). The goal of embolization in cases of intracranial and skull base tumors is selective obliteration of the pathologic intratumoral vasculature while preserving the normal supply to surrounding tissues. In the majority of cases, selective obliteration of the intratumoral vasculature by appropriate embolic materials facilitates subsequent surgical tumor removal by improving the intraoperative conditions in terms of blood loss, almost bloodless tumor exposure, and easy identification of surgically important structures such as cranial nerves (Valavanis 1990). In conjunction with these advantages, embolization of intracranial and skull base tumors contributes to shortening of the operation time, increasing the rate of radical tumor removal, reducing the surgical complication rate, and possibly reducing the incidence of recurrence. In addition to embolization, the technique of permanent balloon occlusion of the internal carotid artery (ICA) in extensive tumors of the skull base with an intimate relationship to the ICA allows identification and resection of pericarotid tumor extensions without the fear of uncontrollable hemorrhage from the ICA and has thus contributed to safe and radical removal of skull base tumors previously regarded as inoperable (Fisch and Mattox 1988).KeywordsExternal Carotid ArteryOphthalmic ArteryGlomus TumorMiddle Meningeal ArterySkull Base TumorThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The treatment of malignant skull base tumors has improved with the development of skull base surgical approaches that allow en bloc resection of a lesion and increase the efficacy of adjuvant therapies. The anatomical complexity of these lesions and their surroundings has led to a relatively high complication rate. Infection and cerebrospinal fluid fistulas are the most common serious procedure-related complications. They result from the frequent necessity of working in a contaminated space such as the paranasal sinuses as well as from the creation of large dural and skull base defects. The authors have reviewed the literature regarding complications of surgery for malignant skull base lesions and present several techniques and strategies for minimizing their incidence by performing the craniofacial approach to anterior skull base lesions.

Background:Endoscopic surgery is suitable for the transsphenoidal approach; it is minimally invasive and provides a well-lit operative field. The endoscopic skull base approach through the large opening of the sphenoid sinus through both nostrils has extended the surgical indication for various skull base lesions. In this study, we describe the efficacy and complications associated with the endoscopic skull base approach for extra- or intradural parasellar lesions based on our experiences.Methods:Seventy-four cases were treated by an endoscopic skull base approach. The indications for these procedures included 55 anterior extended approaches, 10 clival approaches, and 9 cavernous approaches. The operations were performed through both the nostrils using a rigid endoscope. After tumor removal, the skull base was reconstructed by a multilayered method using a polyglactin acid (PGA) sheet.Results:Gross total resection was achieved in 82% of pituitary adenomas, 68.8% of meningiomas, and 60% of craniopharyngiomas in anterior extended approach and in 83.3% of chordomas in clival approach, but only in 50% of the tumors in cavernous approach. Tumor consistency, adhesion, and/or extension were significant limitations. Visual function improvements were achieved in 37 of 41 (90.2%) cases. Cerebrospinal fluid (CSF) leakage (9.5%), infections (5.4%), neural injuries (4.1%), and vascular injuries (2.7%) were the major complications.Conclusions:Our experiences show that the endoscopic skull base approach is a safe and effective procedure for various parasellar lesions. Selection of patients who are unlikely to develop complications seems to be an important factor for procedure efficacy and good outcome.

Background: Endoscopic endonasal surgery represents a minimally invasive approach that enables surgeons to access and treat various lesions located at the skull base through the nasal cavity. The objective of this study was to assess the outcomes associated with the extended endoscopic endonasal technique in patients diagnosed with skull base tumors, focusing on its safety and effectiveness. Methods: This investigation involved 20 patients presenting with midline skull base lesions, including craniopharyngiomas with intrasellar and moderate suprasellar components, large or giant pituitary adenomas extending significantly into the suprasellar region and anterior cranial base, recurrent skull base masses, and small lesions measuring less than 3-4 cm without lateral extension beyond the optic nerves. Results: Notable improvements were observed in the visual field function of the patients. Statistically significant differences were identified between the preoperative and postoperative functional outcomes (p0.005). Conclusions: The extended endoscopic endonasal approach represents a minimally invasive, safe, and less traumatic surgical technique for managing patients with various skull base tumors.