The quiet revolution: retractorless surgery for complex vascular and skull base lesions

The quiet revolution: retractorless surgery for complex vascular and skull base lesions

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.

See also: Lateral Transorbital Neuroendoscopic Approach to the Lateral Cavernous SinusJ Neurol Surg B Skull Base 2014; 75(01): 011-017DOI: 10.1055/s-0033-1353363

<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.

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.

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.

Since the repopularization of the transsphenoidal approach by Guiot and Hardy, most surgeons have adopted this technique as the primary method for the removal of pituitary adenomas. With the development of modern microinstrumentation, the use of the operating microscope, and advances in endoscopic endonasal instrumentation and navigation, the endonasal transsphenoidal approach has become the preferred method for targeting sellar and parasellar lesions. Exposure beyond the parasellar region in the sagittal and coronal planes can be achieved when the extended transsphenoidal approach is performed using a purely endoscopic endonasal approach (EEA) without a nasal speculum. With the recent advent of extended EEAs, access to a variety of skull base lesions outside of the sella and sphenoid sinus can be accomplished. In the sagittal plane, ventral pathology can be accessed from the frontal sinuses anteriorly to the odontoid process posteroinferiorly. In the coronal plane, lateral access can be achieved to remove lesions occupying the cavernous sinus, infratemporal fossa, middle fossa, and petrous apex. Various endoscopic endonasal corridors have been developed to access a desired target of the ventral skull base. The majority of these EEAs share a common initial transsphenoidal approach to the ventral skull base before branching out into their respective paths along the sagittal or coronal plane. In this chapter, the authors discuss the various endoscopic endonasal corridors that allow access to a wide variety of complex skull base lesions.

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.

Endoscopic approach to lesions of the sphenoid sinus, orbital apex, and clivus

Computer-assisted neuronavigation was used in 87 cases of skull base lesions (SBLs). Preoperative planning and intraoperative identification of anatomic landmarks is especially important in SBLs since it helps to avoid or minimize surgical morbidity and mortality. In this study, we assessed the accuracy and the clinical usefulness of a frameless system based on the optical digitizer in SBLs. Between April 2000 and March 2003, eighty-seven patients with SBLs were operated on in our department using cranial neuronavigation. A passive-marker-based neuronavigation system was used for intraoperative image guidance. There were 56 women and 31 men. The patient's ages ranged from 4 to 76 years (average: 45.7 year). The locations of the tumors reported in this series were as follows: frontobasal, 24 cases; sellar/parasellar, 32 cases; petroclival, 16 cases; tentorial/subtemporal, 15 cases. The computer-calculated registration accuracy ranged between 0.3 and 1.7 mm (mean, 1.1 mm). Gross total removal of the SBLs was accomplished in 82 out of 87 patients as was confirmed on postoperative CT and MRI scans. The follow-up period ranged from 1 month to 48 months (average: 20.1 months). Overall mortality and severe morbidity (meningitis, permanent cranial nerve deficits, and cerebrospinal fluid fistulae) rates were 4.6 % and 33.3 %, respectively. The image-guided surgery is a valuable aid for safe, helpful and complete removal of SBLs of the brain where accurate localization of the lesion is critical. Although our preliminary series is not large, interactive image guidance provides a constant display of surgical instrument position during surgery and its relationship with the SBLs components, surrounding normal brain, and vascular structures, providing valuable guidance to the surgeon during an operation. Our experience with the neuronavigation suggests that image guidance is helpful in this type of lesions, providing better anatomic orientation during skull base surgery, delineating tumor margins and their relation to critical neurovascular structures.

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

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

Objective To analyze the effect of different surgical approaches on anterior skull base and saddle area lesions. Methods Seventy-one patients with anterior skull base and saddle area lesions who were randomly selected between January 2012 and January 2015, of them, 38 cases underwent trans-eyebrow approach surgery were selected as observation group, and 33 cases underwent trans-forehead approach surgery were selected as control group. The degree of tumor resection, surgical time, postoperative complications and the relief of clinical symptoms and improvement of quality of life were compared between the two groups. Results There was no significant differences in the degree of tumor resection or clinical symptoms (headache, visual impairment, endocrine symptoms) between the two groups (P>0.05). The differences in surgical time, intraoperative blood loss and incidence of postoperative complications between observation group [(180.4±18.8) min, (174.7±58.3)ml, 5.3%] and control group [(240.3±32.1) min, (265.73±83.24) ml, 21.2%] were significant (P 0.05). Conclusions Both of trans-eyebrow and trans-forehead approach surgery can significantly relieve the clinical symptoms in patients with anterior skull base and saddle area lesions and improve quality of life. However, the surgical time and hospitalization time of the former is shorter, with less intraoperative blood loss and fewer postoperative complications. Key words: Anterior skull base and saddle area lesions; Trans-eyebrow approach; Trans-forehead approach

Base of skull and cervical spine chordomas in children treated by high-dose irradiation