Decision making for the surgical approach of posterior petrous bone meningiomas

Object The authors undertook this study to examine the surgical approaches used to treat posterior petrous bone meningiomas at a single institution and retrospectively evaluate their surgical strategy based on a previously published classification. Methods Cases in which craniotomies were performed to treat posterior petrous bone meningiomas between 2002 and 2010 were retrospectively reviewed. Data were examined from 57 patients who were treated for 59 tumors. The tumors were classified into 3 types according to the location of their primary dural attachment: Type A, located around the porus trigeminus (33 tumors); Type M, located at the level of the porus of the internal auditory canal (IAC) (12 tumors); and Type P, located laterally to the IAC (14 tumors). The median tumor diameter was 34 mm (range 20–67 mm). Results The choice of the approach was based on tumor location, as the displacement of vascular structures and cranial nerves was primarily determined by the site of dural attachment on the posterior petrous bone. An anterior petrosectomy was performed in 82% of Type A meningiomas, and a retrosigmoid approach was used in 86% of Type P meningiomas. The spectrum of approaches was less uniform for Type M meningiomas. Overall, total resection was obtained in 39% of all cases, and in 18%, 50%, and 86% of Type A, Type M, and Type P tumors, respectively. The postoperative mortality rate was 8.8% (5 deaths among 57 patients), and all 5 patients who died during the early postoperative period had large Type A tumors. At last follow-up, the functional preservation of the facial nerve was excellent in 49 (94%) of the 52 surviving patients. Conclusions The authors believe that proper selection of the approach favorably impacts functional outcome in patients undergoing surgery for the treatment of skull base tumors. In the authors' case series of posterior petrous bone meningiomas, Type P and most Type M tumors were safely managed through a regular retrosigmoid approach, whereas Type A tumors were optimally treated via an epidural anterior petrosectomy.

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Transapical extension in difficult cerebellopontine angle tumours: preliminary report

The Journal of Laryngology & Otology ◽

10.1258/002221503770716214 ◽

2003 ◽

Vol 117 (10) ◽

pp. 788-792 ◽

Cited By ~ 11

Author(s):

Mario Sanna ◽

Manoj Agarwal ◽

Yogesh Jain ◽

Alessandra Russo ◽

Abdel Kader Taibah

Keyword(s):

Vestibular Schwannoma ◽

Cerebellopontine Angle ◽

Cranial Nerves ◽

Internal Auditory Canal ◽

Petrous Bone ◽

Vestibular Schwannomas ◽

Type I ◽

Posterior Surface ◽

Prepontine Cistern ◽

Anterior Extension

Difficult cerebellopontine angle (CPA) tumours namely large/giant vestibular schwannomas, vestibular schwannomas with a significant anterior extension and meningiomas of the posterior surface of the petrous bone extending anterior to the internal auditory canal (IAC) have always posed a problem for the otoneurosurgeon. Modifications of the enlarged translabyrinthine approach (ETLA) specifically aimed at dealing with these tumours are not reported. The aim of this paper is to introduce the transapical extension of ETLA which involves increased circumferential drilling around the IAC beyond 270°C. The extension allows enhanced surgical control over the tumour as well as the anterior aspect of the CPA including the prepontine cistern, the Vth and VIth cranial nerves. The extension is further classified into Type I and II depending upon the extent of drilling. Type I extension entails drilling around the IAC for 300–320° and is indicated for large/giant vestibular schwannomas (large vestibular schwannoma extrameatal diameter 3–3.9 cm, giant vestibular schwannoma extrameatal diameter [ges ]4 cm) and vestibular schwannomas with significant anterior extension. Type II extension involves complete drilling around the canal for 360° and is indicated for meningiomas of the posterior surface of the petrous bone extending anterior to the IAC.

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Preoperative Radiographic Predictors of Hearing Preservation After Retrosigmoid Resection of Vestibular Schwannomas

Otolaryngology ◽

10.1177/0194599820978246 ◽

2020 ◽

pp. 019459982097824

Author(s):

Yin Ren ◽

Kareem O. Tawfik ◽

Bill J. Mastrodimos ◽

Roberto A. Cueva

Keyword(s):

Internal Auditory Canal ◽

Case Series ◽

Hearing Preservation ◽

Vestibular Schwannomas ◽

Tumor Diameter ◽

Retrospective Case ◽

Tumor Extension ◽

Younger Age ◽

Hearing Outcomes ◽

Radiographic Data

Objective To identify preoperative radiographic predictors of hearing preservation (HP) after retrosigmoid resection of vestibular schwannomas (VSs). Study Design Retrospective case series with chart review. Setting Tertiary skull base referral center. Methods Adult patients with VSs <3 cm and word recognition scores (WRSs) ≥50% who underwent retrosigmoid resection and attempted HP between February 2008 and December 2018 were identified. Pure tone average (PTA), WRS, and magnetic resonance imaging radiographic data, including tumor diameter and dimensional extension relative to the internal auditory canal (IAC), were examined. Results A total of 151 patients were included. The average tumor size was 13.8 mm (range, 3-28). Hearing was preserved in 41.7% (n = 63). HP rates were higher for intracanalicular tumors than tumors with cerebellopontine angle (CPA) components (57.6% vs 29.4%, P = .03). On multivariate analysis, maximal tumor diameter (odds ratio [OR], 0.892; P < .001) and preoperative PTA (OR, 0.974; P = .026) predicted HP, while mediolateral tumor diameter predicted postoperative PTA (OR, 1.21; P = .005) and WRS (OR, –1.89; P < .001). For tumors extending into the CPA, younger age (OR, 0.913; P = .012), better preoperative PTA (OR, 0.935; P = .049), smaller posterior tumor extension (OR, 0.862; P = .001), and smaller caudal extension relative to the IAC (OR, 0.844; P = .001) all predicted HP. Conclusion Rates of HP are highest in patients with small intracanalicular VSs and good preoperative hearing. For tumors extending into the CPA, greater posterior and caudal tumor extension relative to the IAC may portend worse hearing outcomes.

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Surgical Resection of Cerebellopontine Epidermoid Cysts: Limitations and Outcome

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0037-1606220 ◽

2017 ◽

Vol 79 (02) ◽

pp. 167-172 ◽

Cited By ~ 2

Author(s):

Ahmed Farhoud ◽

Wael Khedr ◽

Hisham Aboul-Enein

Keyword(s):

Cranial Nerves ◽

Postoperative Mortality ◽

Residual Tumor ◽

Retrosigmoid Approach ◽

Subtotal Resection ◽

Total Resection ◽

Surgical Strategies ◽

Epidermoid Cysts ◽

Presenting Symptoms

Objective Epidermoid cysts are benign slowly growing tumors commonly involving the cerebellopontine angle (CPA). The aim of this study was to analyze the surgical limitations, surgical strategies, complications, and outcome of resection of these lesions. Material and Methods The clinical data and outcome of 32 cases operated for CPA epidermoid between 2007 and 2015 were retrospectively analyzed. The mean follow-up period was 42.6 months, and all patients were followed up at least for a whole year. Results There were 15 males and 17 females. The median age was 37.6 years. Headache and cranial nerves dysfunction were the most common presenting symptoms. Surgery was performed in all patients using the standard lateral suboccipital retrosigmoid approach. In three cases, microvascular decompression of an arterial loop was performed in addition to tumor excision. Total resection was accomplished in 19 out of 32 cases (59.4%), subtotal resection in 7 cases (21.9%), and only partial excision was achieved in 6 cases (18.7%). There was no recurrence or regrowth of residual tumor during the follow-up period. We had a single postoperative mortality due to postoperative pneumonia and septic shock. New cranial nerves deficits occurred in 15.6% of cases but were transient in most of them. Conclusion The favorable outcome of total resection of CPA epidermoids should always be weighed against the critical risks that accompany it especially in the presence of tight adhesions to vital neurovascular structures. The retrosigmoid approach is suitable for the resection of these tumors even if they were large in size.

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Combined Microscopic-Endoscopic Transmastoid Resection of a Petrous Meningioma: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opab340 ◽

2021 ◽

Author(s):

Walid Ibn Essayed ◽

Emad Aboud ◽

Ossama Al-Mefty

Keyword(s):

Cranial Nerves ◽

Petrous Bone ◽

Sigmoid Sinus ◽

Petrous Apex ◽

Surgical Removal ◽

Endoscopic Techniques ◽

Petroclival Meningiomas ◽

Close Relationship ◽

Dural Attachment ◽

Cerebellar Retraction

Abstract Petrous meningiomas are defined as tumors with a basal dural attachment on the posterior surface of the petrous bone.1 Their insertion can be anterior to the meatus (petrous apex meningiomas), or posterior to the meatus, with associated hyperostotic bony invasion either pre- or retro-meatal.2 These meningiomas are amenable to curative surgical removal and have better surgical outcomes than more medially located true petroclival meningiomas that originate medial to the fifth nerve.2-4 They, however, remain challenging because of their close relationship to critical neurovascular structures in the cerebellopontine angle.5 The posterior petrous meningiomas might reach a significant size with compression of the cerebellum, the brainstem, and involvement of the cranial nerves, and extend posteriorly to the transverse sigmoid sinus.2,6 Transmastoid approach with skeletonization and lateral reflection of the transverse sigmoid sinus provides a superb exposure without cerebellar retraction.6,7 The ease and complete resection of the tumor and invaded bone can be facilitated by combined microscopic-endoscopic techniques. We demonstrate these principles through the resection of a petrosal meningioma in a 56-yr-patient who presented with headaches, nystagmus, and mild cerebellar signs. The patient consented to the procedure. Image at 1:36 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, ©LWW, 1998.

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Surgical removal of giant acoustic neurinomas involving the skull base

Journal of Neurosurgery ◽

10.3171/jns.1989.71.4.0611 ◽

1989 ◽

Vol 71 (4) ◽

pp. 611-615 ◽

Cited By ~ 2

Author(s):

Yutaka Sawamura ◽

Yoku Nakagawa ◽

Toshio Ikota ◽

Hiroshi Abe

Keyword(s):

Skull Base ◽

Temporal Bone ◽

Infratemporal Fossa ◽

Cranial Nerves ◽

Internal Auditory Canal ◽

Petrous Bone ◽

Neurological Deficits ◽

Surgical Removal ◽

Sphenoidal Sinus ◽

Content Type

✓ Neurinomas arising from the peripheral branch of the acoustic nerve distal to the internal auditory canal in the temporal bone are rare. Two advanced skull-base neurinomas are described which were situated mainly in the temporal petrous bone, and extended to the parapharyngeal space anteriorly, to the lateral cervical portion inferiorly, into the sphenoidal sinus medially, and into the middle and posterior cranial fossae compressing the brain stem. Both patients had been deaf for several years without other neurological deficits. The operative findings revealed that the fifth, seventh, and caudal cranial nerves were intact; therefore, it was suspected that these neurinomas originated primarily within the cochlea or the vestibule in the temporal bone. The tumors were completely removed via an extradural approach, with good results. Since the surgical treatment of such advanced skull-base neurinomas is difficult, the operative infratemporal fossa approach is described in detail.

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Foramen magnum meningiomas: surgical results and risks predicting poor outcomes based on a modified classification

Journal of Neurosurgery ◽

10.3171/2016.2.jns152873 ◽

2017 ◽

Vol 126 (3) ◽

pp. 661-676 ◽

Cited By ~ 6

Author(s):

Da Li ◽

Zhen Wu ◽

Cong Ren ◽

Shu-Yu Hao ◽

Liang Wang ◽

...

Keyword(s):

Cranial Nerves ◽

Multivariate Logistic Regression Analysis ◽

Type A ◽

Foramen Magnum ◽

Neurological Function ◽

Preoperative Imaging ◽

Long Term Outcome ◽

Lower Cranial Nerve ◽

Dural Attachment

OBJECTIVE This study aimed to evaluate neurological function and progression/recurrence (P/R) outcome of foramen magnum meningioma (FMM) based on a modified classification. METHODS This study included 185 consecutive patients harboring FMMs (mean age 49.4 years; 124 females). The authors classified the FMMs into 4 types according to the previous classification of Bruneau and George as follows: Type A (n = 49, 26.5%), the dural attachment of the lesion grows below the vertebral artery (VA); Type B (n = 39, 21.1%), the dural attachment of the lesion grows above the VA; Type C1 (n = 84, 45.4%), the VA courses across the lesion with or without VA encasement or large lesions grow both above and below the bilateral VA; and Type C2 (n = 13, 7.0%), Type C1 plus partial/total encasement of the VA and extradural growth. RESULTS The median preoperative Karnofsky Performance Scale (KPS) score was 80. Gross-total resection (GTR) was achieved in 154 patients (83.2%). Lower cranial nerve morbidity was lowest in Type A lesions (16.3%). Type C2 lesions were inherently larger (p = 0.001), had a greater percentage of ventrolateral location (p = 0.009) and VA encasement (p < 0.001), lower GTR rate (p < 0.001), longer surgical duration (p = 0.015), higher morbidity (38.5%), higher P/R rate (30.8%, p = 0.009), and poorer recent KPS score compared with other types. After a mean follow-up duration of 110.3 months, the most recent follow-up data were obtained in 163 patients (88.1%). P/R was observed in 13 patients (7.2%). The median follow-up KPS score was 90. Compared with preoperative status, recent neurological status was improved in 91 (49.2%), stabilized in 76 (41.1%), and worsened in 18 (9.7%) patients. The multivariate Cox proportional hazard regression model demonstrated Type C2 (HR 3.94, 95% CI 1.04–15.0, p = 0.044), nontotal resection (HR 6.30, 95% CI 1.91–20.8, p = 0.003), and pathological mitosis (HR 7.11, 95% CI 1.96–25.8, p = 0.003) as independent adverse predictors for tumor P/R. Multivariate logistic regression analysis identified nontotal resection (OR 4.06, 95% CI 1.16–14.2, p = 0.029) and pathological mitosis (OR 6.29, 95% CI 1.47–27.0, p = 0.013) as independent risks for poor outcome (KPS score < 80). CONCLUSIONS The modified classification helped to predict surgical outcome and P/R in addition to the position of the lower cranial nerves. Preoperative imaging studies and neurological function should be reviewed carefully to establish an individualized management strategy to improve long-term outcome.

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Use of Neuroanatomic Knowledge and Neuronavigation System for a Safe Anterior Petrosectomy

Brain Sciences ◽

10.3390/brainsci11040488 ◽

2021 ◽

Vol 11 (4) ◽

pp. 488

Author(s):

Ana Flores-Justa ◽

Sabino Luzzi ◽

Alice Giotta Lucifero ◽

Juan F. Villalonga ◽

Amparo Saenz ◽

...

Keyword(s):

Anterior Part ◽

Internal Auditory Canal ◽

Petrous Bone ◽

Surgical Approaches ◽

Illustrative Case ◽

Petroclival Region ◽

Anterior Transpetrosal Approach ◽

Neuronavigation System ◽

Anterior Petrosectomy ◽

Key Aspects

Introduction: The petroclival region is among the most challenging anatomical areas to deal with in skull base surgery. Drilling of the anterior part of the petrous bone during the anterior transpetrosal approach involves the risk of injury of the cochlea, superior semicircular canal, internal carotid artery, and internal auditory canal. A thorough understanding of the microneurosurgical anatomy of this region is mandatory to execute the transpetrosal approaches, decreasing the risk of complications. The aim of this study is to describe the anatomical structures of the petroclival region, highlighting the importance of neuronavigation for safe performance of the anterior transpetrosal approach. Methods: Three adult cadaveric human heads were formalin-fixed and injected with colored silicone. They underwent an axial 1 mm slab CT scan, which was used for neuronavigation during the surgical approaches. The anterior petrosectomy was performed with the aid of neuronavigation during the drilling of the petrous bone. The surgical management of a patient harboring a petroclival meningioma, operated on using an anterior transpetrosal approach, was reported as an illustrative case. Results: The anterior petrosectomy was completed accurately with wide exposure of the surgical target without injuring the cochlea and other structures in all three cadaveric specimens. In the surgical case, no approach-related complications occurred, and a gross total resection of the tumor was achieved. Conclusions: Deep knowledge of the location and relationships of the vital elements located within the temporal bone, along with the use of neuronavigation, are the key aspects to perform the anterior transpetrosal approach safely, reducing the risk of complications.

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68Ga-DOTATOC PET/CT Follow Up after Single or Hypofractionated Gamma Knife ICON Radiosurgery for Meningioma Patients

Brain Sciences ◽

10.3390/brainsci11030375 ◽

2021 ◽

Vol 11 (3) ◽

pp. 375

Author(s):

Fabio Barone ◽

Francesco Inserra ◽

Gianluca Scalia ◽

Massimo Ippolito ◽

Sebastiano Cosentino ◽

...

Keyword(s):

Gamma Knife ◽

Case Series ◽

Biological Response ◽

Standardized Uptake Value ◽

Emission Tomography ◽

Tumor Diameter ◽

Relative Percentage ◽

Positron Emission ◽

Pet Ct

68Ga-DOTATOC represents a useful tool in tumor contouring for radiosurgery planning. We present a case series of patients affected by meningiomas on who we performed 68Ga-DOTATOC positron emission tomography (PET)/CT pre-operatively, a subgroup of which also underwent a post-operative 68Ga-DOTATOC PET/CT to evaluate the standardized uptake value (SUV) modification after Gamma Knife ICON treatment in single or hypofractionated fractions. Twenty patients were enrolled/included in this study: ten females and ten males. The median age was 52 years (range 33–80). The median tumor diameter was 3.68 cm (range 0.12–22.26 cm), and the median pre-radiotherapy maximum SUV value was 11 (range 2.3–92). The average of the relative percentage changes between SUVs at baseline and follow up was −6%, ranging from −41% to 56%. The SUV was reduced in seven out of 12 patients (58%), stable in two out of 12 (17%), and increased in three out of 12 (25%), suggesting a biological response of the tumor to the Gamma Knife treatment in most of the cases. 68Ga-DOTATOC-PET represents a valuable tool in assessing the meningioma diagnosis for primary radiosurgery; it is also promising for follow-up assessment.

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