Intradural Extension Research Articles

Endoluminal Sigmoid Sinus Occlusion During Jugular Foramen Tumor Surgery: Novel Technique, Operative Nuances, and Clinical Experience With 33 Patients.

Surgery of jugular foramen tumors (JFTs) often requires vascular control by means of ligating the internal jugular vein and sigmoid sinus (SS) to allow intrabulbar access. Occlusion of the SS traditionally involves presigmoid and retrosigmoid durotomies allowing introduction of ligature devices, predisposing to cerebrospinal fluid (CSF) leakage and pseudomeningoceles. We describe a simple and novel endoluminal sigmoid sinus occlusion (ESSO) technique with Gelfoam that is entirely extradural. An extended anterolateral infralabyrinthine approach with ESSO was performed in 33 patients with JFTs. After ligating the internal jugular vein, the SS is opened and Gelfoam is placed endoluminally into the proximal SS. Care is taken to avoid occlusion of the venous outflow of the vein of Labbe to avoid temporal lobe venous infarction. Hemostatic gelatin matrix is injected distally to stop venous backflow from the inferior petrosal sinus. The jugular venous system is isolated, and the outer jugular wall can be opened to expose the JFT for resection. There were no complications of temporal lobe venous infarction or postoperative hematoma observed. Four patients with intradural tumor extension developed pseudomeningoceles. For patients with purely extradural JFTs, none developed postoperative incisional CSF leaks and one had pseudomeningocele. This ESSO technique is fast and effective, permitting occlusion of the SS during JFT surgery. It has the advantage of being entirely extradural, avoiding durotomy which can result in postoperative CSF leak. It is important to keep the Gelfoam distal to the transverse-sigmoid junction to avoid occlusion of the vein of Labbe inlet and temporal lobe venous infarction.

C2 Nerve Sheath Tumors: An Analysis of Radiological – Intraoperative Concordance for Intradural Extension and Systematic Review

Background: Nerve sheath tumors (NSTs) of C2 nerve-root are clinically and radiologically distinct from NSTs of rest of the spine. On imaging, they appear to have a major intradural component in addition to the large extradural part. Thus, they may require durotomy with its possible added complications. Objective: The aim of this study is to evaluate the radiological – intra-operative discordance for intradural component and need for tailored durotomy for complete resection of C2 NSTs. Material and Methods: We retrospectively analyzed 14 consecutively operated patients of C2 NSTs over the past 10 years (2013-2023). Dura was opened in patients where there was a radiological or intra-operative suspicion of intradural extension. Results: Mean(±SD) age at presentation was 37.5(±13) years, with no gender predominance (Male:Female-1.3:1). Dura was opened in 7(50%) patients. On preoperative radiological study, all the patients had a dominant extradural tumor, while 7(50%) patients appeared to have an intradural tumor extension also. Intra-operatively, 5(35.7%) of these 7 patients had only extradural component, while 2(14.3%) patients had an intradural extension. 7(50%) patients had extradural tumor radiologically, while only one patient was found to have a small intradural extension intraoperatively. Thus, only 21.4% of the patients (n=3) were found to have an intradural extension as against 50%(n=7) predicted on imaging. Post-operatively there was clinical improvement in all 14 patients (100%). Conclusions: Due to radiological and intra-operative discordance in intradural tumor extension, decision for midline durotomy should be taken following excision of extradural component. Thus, limiting the number of unnecessary midline-durotomies.

An audit of neoadjuvant chemotherapy in sinonasal teratocarcinosarcoma from an academic tertiary care centre in India.

e18109 Background: Sinonasal teratocarcinosarcoma (SNTCS) are rare types of sinonasal malignancies, incidence is approximately 3% of all head and neck cancers and less than 1% of all tumors. There is very limited literature available on SNTCS and most of the literature available is in the form of case reports and small case series. The management of these tumors is complicated because of the location and paucity of data available in such scenarios where resection becomes difficult in extensive disease and the role of neoadjuvant chemotherapy (NACT) becomes significant. This audit was performed to study the tolerance and outcomes with NACT followed by surgery(Sx) in these treatment protocols. Methods: A retrospective analysis of a prospectively maintained database approved by the IEC of TMH. The baseline characteristics, extent of tumor, type of NACT, adverse events was curated from the EMR and patients' hospital files. Patients with clinically or radiologically extensive/inoperable disease at presentation were planned for NACT for a duration of 6-8 weeks. Post NACT these patients underwent axial imaging for response assessment.(RECIST v1.1). The adverse events due to NACT were noted as per CTCAE v5.0. Results: There were 27 patients of SNTCS. The median age of the whole cohort was 42 years (IQR 30-56) and 85.2% (n=23) were male. The ECOG PS was 0-1 in 24 (88.8%) patients and only 3 (11.1%) patients had ECOG PS 2. 17 patients (63%) had a history of addiction. 7 patients had clinical palpable regional nodes (25.9%) and 1 patient (3.7%) had lung metastasis at presentation. All 27 patients received NACT in view of extensive disease .15 patients (55.6%) had intracranial extension of disease with intradural extension. Only 10 patients (37%) had intraparenchymal disease. 22 patients (81.5%) had Kadish stage C-D disease and the remaining 5 patients (18.5%) had Kadish stage B at baseline. 20 patients (74.1%) received Cisplatin & Etoposide as NACT and remaining 7 received other chemotherapy. Median number of chemotherapy cycles was 2 (Q1 is 2 - Q3 is 3). 1 patient (3.7%) did not complete the planned NACT due to toxicity. The incidence of grade 3-5 toxicity in accordance with CTCAE version 5.0 was 37.03%. There was 1 death (3.7%) due to chemotherapy toxicity. Details of response to NACT are given in the table. 18 patients (77.8%) underwent Sx, 5 patients (18.5%) received CTRT and 2 patients (7.4%) received definitive RT and 2 patients (7.4%) did not receive any local therapy .Post Sx in local node was found in 3 patients (11.11%).The 2 years progression free survival was 53.2%(95%CI 31.3 - 70.9) and 2 years overall survival was 60.9%(95%CI 37.6 - 77.8). Conclusions: NACT improves survival in locally advanced SNTC with significant response rates. [Table: see text]

Long-term operative outcome of giant calcified thoracic disc herniation - A retrospective analysis of 24 patients.

Thoracic disc herniations (TDHs) are rare (0.15-4%) and often cause significant myelopathy (70-95%). They are defined as "Giant" if they occupy >40% of the spinal canal. Further, they are ossified/calcified in 42% of cases, with a 70% incidence of intradural extension. Here, we reviewed our experience resecting 24 giant thoracic discs utilizing a posterolateral surgical approach. Over a 2-year period, we evaluated the outcomes for 24 patients averaging 40 years of age undergoing posterolateral resections of giant ossified/calcified TDH. We evaluated multiple clinical and radiographic parameters; demographics, Frankel grades, surgical time, perioperative complications, and number of levels involved. In addition, utilizing magnetic resonance/computed tomography studies, we documented that the most commonly involved level was T11-T12, and the average canal occupancy ratio (i.e., degree of canal encroachment) was 58.2 ± 7.72%. Neurological improvement was seen in 22 of the 24 patients; none experienced neurological deterioration over the average 2-year post-operative period. Six complications occurred; three dural tears and three suture site infections. The posterolateral approach proved to be safe and effectively for resecting 24 giant ossified/calcified TDH with minimum complications.

Management strategies in clival and craniovertebral junction chordomas: a 29-year experience.

Chordomas represent one of the most challenging subsets of skull base and craniovertebral junction (CVJ) tumors to treat. Despite extensive resection followed by proton-beam radiation therapy, the recurrence rate remains high, highlighting the importance of developing efficient treatment strategies. In this study, the authors present their experience in treating clival and CVJ chordomas over a 29-year period. The authors conducted a retrospective study of clival and CVJ chordomas that were surgically treated at their institution from 1991 to 2020. This study focuses on three aspects of the management of these tumors: the factors influencing the extent of resection (EOR), the predictors of survival, and the outcomes of the endoscopic endonasal approaches (EEAs) compared with open approaches (OAs). A total of 265 surgical procedures were performed in 210 patients, including 123 OAs (46.4%) and 142 EEAs (53.6%). Tumors that had an intradural extension (p = 0.03), brainstem contact (p = 0.005), cavernous sinus extension (p = 0.004), major artery encasement (p = 0.01), petrous apex extension (p = 0.003), or high volume (p = 0.0003) were significantly associated with a lower EOR. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 52.1% and 75.1%, respectively. Gross-total resection and Ki-67 labeling index < 6% were considered to be independent prognostic factors of longer PFS (p = 0.0005 and p = 0.003, respectively) and OS (p = 0.02 and p = 0.03, respectively). Postoperative radiation therapy correlated independently with a longer PFS (p = 0.006). Previous surgical treatment was associated with a lower EOR (p = 0.01) and a higher rate of CSF leakage after EEAs (p = 0.02) but did not have significantly lower PFS and OS compared with primary surgery. Previously radiation therapy correlated with a worse outcome, with lower PFS and OS (p = 0.001 and p = 0.007, respectively). EEAs were more frequently used in patients with upper and middle clival tumors (p = 0.002 and p < 0.0001, respectively), had a better rate of EOR (p = 0.003), and had a lower risk of de novo neurological deficit (p < 0.0001) compared with OAs. The overall rate of postoperative CSF leakage after EEAs was 14.8%. This large study showed that gross-total resection should be attempted in a multidisciplinary skull base center before providing radiation therapy. EEAs should be considered as the gold-standard approach for upper/middle clival lesions based on the satisfactory surgical outcome, but OAs remain important tools for large complex chordomas.

134 Case Report and Review of Literature: Advanced Sino-Nasal Adenoid Cystic Carcinoma with Intracranial and Intradural Extension

Abstract Introduction Adenoid cystic carcinoma (ACC) is a rare cancer of the head and neck that primarily occurs in the salivary glands. Sino-nasal ACC (SNACC) is a much rarer entity; this paper presents an exceedingly rare case of SNACC with both intracranial and intradural extension. In addition to this, a review of the literature has been performed. Case Study Our case describes the diagnosis of SNACC with both intracranial and intradural extension in a 55yr old female which was subsequently managed with palliative radiotherapy. Review of literature and Conclusions Currently, there are only few larger studies that have been conducted on SNACC and only isolated case reports of SNACC with intracranial extension. Aggregated data suggests that SNACC tends to present late at T3-T4 stage, has a 5-year survival of 60% and holds the best prognosis when surgical resection is feasible. From our case and the four other cases published on SNACC with intracranial extension it can be seen there is a clear distinction with management of patients with or without intradural extension. Intradural extension is a contraindication to surgical resection and once found deems the disease stage as primarily palliative. The focus for treatment of SNACC particularly with intracranial extension should catch disease early and prevent intradural spread. This maximises the number of patients who can undergo surgical resection and improves prognosis.

Robot-assisted resection of a dumbbell-shaped intradural tumor in the prone position.

The resection of Eden type 2 or 3 dumbbell-shaped tumors has traditionally been performed by a combination of prone laminectomy and lateral video-assisted thoracic surgery (VATS).1 Okazaki and colleagues2 reported the usefulness of robot-assisted intrathoracic procedure for the resection of epidural dumbbell-shaped dorsal spine tumors, with the patient in the prone position and without need for repositioning. Here, we were performed a robot-assisted thoracoscopic surgery (RATS) for an Eden type 2 schwannoma with intradural extension.

Operative Technique for Resection of a Ventral Transdural Retro-Odontoid Pannus: A 2-Dimensional Operative Video

Retro-odontoid pseudotumors are rare inflammatory complications of atlantoaxial instability often associated with cervical degenerative disease and rheumatoid arthritis. While propagation of these lesions has been shown to cause spinal cord compression and cervical myelopathy, intradural extension has rarely been reported. In this manuscript and 2-dimensional illustrative intraoperative video, we demonstrate cervical decompression, removal of the intradural component, and stabilization with C1-2 instrumentation using a posterior approach. A 71-year-old patient presented with progressive cervical myelopathy. Preoperative imaging demonstrated a large retro-odontoid pannus causing severe spinal cord compression and an associated contrast-enhancing intradural lesion, in the absence of obvious C1-2 instability or fractures on computed tomography scan. C1-2 posterior decompression and fusion were performed with maximally safe intradural pannus resection and ventral dural reconstruction. Postoperatively, the patient experienced significant improvement in myelopathic symptoms. Imaging demonstrated good spinal cord decompression with complete intradural pannus resection and debulking of the extradural component. Our outcome in this rare complication suggests a posterior approach may be effective in treating similar patients.

Lumbosacral plexopathy caused by the perineural spread of pelvic malignancies: clinical aspects and imaging patterns.

Perineural spread (PNS) of tumors from pelvic malignancies is a rare phenomenon but constitutes an important differential diagnosis of lumbosacral plexopathy (LSP). Herein, we describe the clinical and imaging features of patients with LSP due to PNS of pelvic malignancies along with a literature review. We retrospectively reviewed 9 cases of LSP caused by PNS of pelvic malignancy between January 2006 and August 2021, and all clinical and imaging parameters were recorded in detail. Clinical symptoms and signs of patients were described and listed in the order in which they occurred. The results of imaging test were analyzed to describe specific findings in LSP caused by PNS. This study enrolled nine adult patients (mean age, 50.1years). Two cases initially presented as LSP and were later diagnosed with pelvic malignancy. Pain in the perianal or inguinal area preceded pain at the extremities in six patients. Neurogenic bladder or bowel symptoms developed in five patients. On the magnetic resonance imaging (MRI), the S1-S2 spinal nerve was most commonly involved, and S1 myotome weakness was more prominent in six patients than the other myotomes. One patient had an intradural extension. 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) showed abnormal signal intensity in six patients. No abnormality in 18F-FDG PET/CT was detected in the nervous structures in one patient. Only four patients survived until the last follow-up visit. Though rare, physicians should always keep in mind the possibility of LSP due to the PNS in patients with pelvic malignancy. Thorough physical examination and history taking could provide clues for diagnosis. Pelvic MRI and 18F-FDG-PET/CT should be considered for patients with LSP to rule out neoplastic LSP.

Dumbbell chondrosarcoma of lumbar spine with intradural extension

Chondrosarcomas are very rare tumors of the spine constituting for only 10% of all bony tumors and 12% of primary malignant tumors of the spine. It is the third most common primary malignant bone tumor after osteosarcoma and Ewing's sarcoma, and the third most common primary malignant tumor of the spine after chordoma and osteosarcoma. The thoracic vertebrae are the most commonly affected, followed by the cervical and lumbar. These are slow-growing tumors and are usually asymptomatic until late in their course when they cause neurological deficits by compression on the thecal sac, spinal cord, or nerve roots. As is the case for all malignant spinal tumors, en bloc resection without contamination or violation of the reactive zone (pseudocapsule) is the most appropriate surgical strategy, but in some cases, this is impossible due to unacceptable morbidity because of close proximity to critical neurovascular structures or multicompartmental location of the tumor. Here, we describe a case of L5 chondrosarcoma arising from the left pedicle with significant intradural and extraspinal components. Intradural extension of chondrosarcomas, or for that matter any malignant spinal tumor, has never been reported in literature.

A rare case of advanced sinonasal adenoid cystic carcinoma with intracranial and intradural extension

Adenoid cystic carcinoma (ACC) is a rare cancer of the head and neck that primarily occurs in the salivary glands. Sino-nasal ACC (SNACC) is a much rarer entity; this paper presents an exceedingly rare case of SNACC with both intracranial and intradural extension which was ultimately treated with palliative radiotherapy due to its extensive invasion. In addition to this, a review of the literature has been performed to delineate specific learning points for the management of intracranial SNACC.

Hyperostotic Invasive Meningioma of the Sphenoid Ridge Surgical Considerations: 2-Dimensional Operative Video.

Hyperostotic invasive sphenoid ridge meningiomas are a distinct and recognized entity.1-4 They are characterized by extensive bone involvement and expansive “en plaque” intradural extension.3,5 The goal of this surgery is improving and preserving the visual function and ocular motility while esthetically correcting and reconstructing the exophthalmos and temporal deformity.4,5 The surgery includes radical removal of the involved bone of the sphenoid ridge, orbital walls, and middle fossa floor, in addition to the “en plaque” dural and periorbital involvement and intradural extension.3,5,6 Early decompression of the optic nerve and orbital elements allows preventing visual function deterioration and yields frequent improvement. Thorough planned reconstruction can be achieved by molding a malleable mesh to the patient's skull before the extensive bone removal. Careful orbital wall reconstruction allows one to achieve a good postoperative cosmesis and prevent enophthalmos.4 We demonstrate the principles of this surgery through 2 cases of 46-year-old and 53-year-old women. The first case demonstrates the importance of middle fossa extensive drilling of involved bone and reconstruction while the second case demonstrates the visual decompression and postoperative improvement. The patients consented to the surgeries and publication of their images.

Preservation of Cranial Nerves Function in Glomus Jugulare Surgery: 2-Dimensional Operative Video

Owing to their invasive character, extreme vascularity, and critical location, glomus jugulare tumors present a formidable challenge. Techniques have been developed for safe and successful removal of even giant glomus paragangliomas.1-3 Preoperative evaluation including genetic, hormonal, and multiplicity workup4 has enhanced the safety of surgical management, as did modern preoperative embolization by eliminating excessive blood loss.5 Despite these advancements, surgical outcomes of glomus jugulare remain haunted by cranial nerve dysfunction such as facial nerve palsies and hearing loss, with lower cranial nerves dysfunction being the most morbid. These can be avoided by technical maneuvers to preserve the cranial nerves. The external ear canal is not closed to maintain conductive hearing. The facial nerve is not transpositioned and kept inside a bony protective canal. Cranial nerves IX, X, and XI are the most vulnerable because they pass through the jugular foramen ventral to the venous bulb wall. They are preserved by intrabulbar dissection that maintains a protective segment of the venous wall over the nerves. By mastering the anatomy of the upper neck, meticulous dissection is performed to preserve the course of IX, X, XI, and XII.6,7 Ligation of the jugular vein is delayed until the tumor is totally isolated to avoid diffuse bleeding.7 We present the case of a 60-yr-old woman with a glomus jugulare tumor with intradural, extradural, and cervical extension. The technical nuances of cranial nerves preservation are demonstrated. The patient consented to the procedure and publication of her images. Images at 2:12, 2:50, and 3:09 from Al-Mefty and Teixeira,6 with permission from JNSPG.

Endoscope-assisted far-lateral transcondylar approach for craniocervical junction chordomas: a retrospective case series and cadaveric dissection.

Craniocervical junction (CCJ) chordomas are a neurosurgical challenge because of their deep localization, lateral extension, bone destruction, and tight relationship with the vertebral artery and lower cranial nerves. In this study, the authors present their surgical experience with the endoscope-assisted far-lateral transcondylar approach (EA-FLTA) for the treatment of CCJ chordomas, highlighting the advantages of this corridor and the integration of the endoscope to reach the anterior aspect and contralateral side of the CCJ and the possibility of performing occipitocervical fusion (OCF) during the same stage of surgery. Nine consecutive cases of CCJ chordomas treated with the EA-FLTA between 2013 and 2020 were retrospectively reviewed. Preoperative characteristics, surgical technique, postoperative results, and clinical outcome were analyzed. A cadaveric dissection was also performed to clarify the anatomical landmarks. The male/female ratio was 1.25, and the median age was 36 years (range 14-53 years). In 6 patients (66.7%), the lesion showed a bilateral extension, and 7 patients (77.8%) had an intradural extension. The vertebral artery was encased in 5 patients. Gross-total resection was achieved in 5 patients (55.6%), near-total resection in 3 (33.3%), and subtotal resection 1 (11.1%). In 5 cases, the OCF was performed in the same stage after tumor removal. Neither approach-related complications nor complications related to tumor resection occurred. During follow-up (median 18 months, range 5-48 months), 1 patient, who had already undergone treatment and radiotherapy at another institution and had an aggressive tumor (Ki-67 index of 20%), showed tumor recurrence at 12 months. The EA-FLTA provides a safe and effective corridor to resect extensive and complex CCJ chordomas, allowing the surgeon to reach the anterior, lateral, and posterior portions of the tumor, and to treat CCJ instability in a single stage.

Identification of the Extradural and Intradural Extension of Pituitary Adenomas to the Suprasellar Region: Classification, Surgical Strategies, and Outcomes.

ObjectiveSuprasellar pituitary adenomas (PAs) can be located in either extradural or intradural spaces, which impacts surgical strategies and outcomes. This study determined how to distinguish these two different types of PAs and analyzed their corresponding surgical strategies and outcomes.MethodsWe retrospectively analyzed 389 patients who underwent surgery for PAs with suprasellar extension between 2016 to 2020 at our center. PAs were classified into two main grades according to tumor topography and their relationships to the diaphragm sellae (DS) and DS-attached residual pituitary gland (PG). Grade 1 tumors were located extradurally and further divided into grades 1a and 1b, while grade 2 tumors were located intradurally.ResultsOf 389 PAs, 292 (75.1%) were surrounded by a bilayer structure formed by the DS and the residual PG and classified as grade 1a, 63 (16.2%) had lobulated or daughter tumors resulting from the thinning or absence of the residual PG and subsequently rendering the bilayer weaker were classified as Grade 1b, and the remaining 34 (8.7%) PAs that broke through the DS or traversed the diaphragmic opening and encased suprasellar neurovascular structures were classified as Grade 2. We found that the gross total removal of the suprasellar part of grade 1a, 1b, and 2 PAs decreased with grading (88.4%, 71.4%, and 61.8%, respectively). The rate of major operative complications, including cerebrospinal fluid leakage, hemorrhage, and death, increased with grading.ConclusionsIt is essential to identify whether PAs with suprasellar extension are located extradurally or intradurally, which depends on whether the bilayer structure is intact. PAs with an intact bilayer structure were classified as grade 1. These were extradural and usually had good surgical outcomes and lower complications. PAs with no bilayer structure surrounding them were classified as grade 2. These were intradural, connected to the cranial cavity, and had increased surgical complications and a lower rate of gross total removal. Different surgical strategies should be adopted for extradural and intradural PAs.

Concurrent Inverted Papilloma and Squamous Cell Carcinoma with Intradural Extension Presenting with Frontal Lobe Syndrome

AbstractInverted papilloma is an uncommon tumor mostly arising from the lateral wall of the nasal cavity and displays a benign but locally aggressive behavior. Intracranial extension is an extremely rare presentation of inverted papilloma. Extension occurs either as a benign lesion or due to malignant transformation. We report a case of concurrent inverted papilloma and squamous cell carcinoma presenting with epistaxis and recent-onset altered behavior and memory impairment. After literature review of similar cases having inverted papilloma with intracranial extension, we could identify a total of 12 cases, most of which were recurrences of a primary inverted papilloma that were resected before extension into the cranial cavity. Most cases were of extradural extension, and intradural spread resulted in poor prognosis on follow-up. Concurrent inverted papilloma and squamous cell carcinoma extending into the anterior cranial fossa and frontal lobe is a very rare clinical entity and can present as frontal lobe syndrome.

Vertebrobasilar Artery Encasement by Skull Base Chordomas: Surgical Outcome and Management Strategies.

Vascular encasement by skull base chordomas can increase surgical risk and hinder completeness of resection. However, the evidence behind this remains anecdotic. To give a better portrayal of chordomas encasing vertebrobasilar arteries mainly in regard of surgical vascular risk and its impact on extent of resection. A retrospective cohort study comparing skull base chordomas with encasement (≥180o encirclement) of the vertebrobasilar arteries to a control group of skull base chordomas with intradural extension. Data gathered involved pre- and postoperative volumetric analysis of the tumor, degree of encasement of involved vessel, occurrence of complication, and survival data including progression-free survival (PFS) and overall survival (OS). A total of 24 patients with vertebrobasilar encasement were included in the study and an equal number of control cases were randomly selected from the same time period, totalizing 48 patients. Lower clival tumors with condyle involvement were more likely to have encasement. Gross total resection (GTR) rate was significantly lower in the encasement group (13% vs 42%, P=.023). Rates of postoperative new neurological deficit, CFS leak and 30 d postoperative mortality were not statistically different between groups. There was no statistically significant difference in mean PFS (P=.608) and OS (P=.958). Skull base chordomas encasing vertebrobasilar arteries are highly challenging tumors. This study demonstrates that although safe resection is possible, GTR is hindered by the presence of encasement. We advocate letting the tumor's adherence to vessels lead the resection, leaving a small piece of tumor behind if adherent to the vessels.

The endolymphatic sac tumor: challenges in the eradication of a localized disease.

Identify the critical points that lead to recurrences and lack of radicality in endolymphatic sac tumors (ELSTs). Retrospective case study and review of the literature. Tertiary referral center. Thirteen cases of ELST were included in the study and their preoperative, intraoperative and postoperative data were analyzed and compared to a review of the literature. Therapeutical. Prevalence of recurrent and residual tumors, comparison to the literature and analysis of ELST characteristics. Diagnosis was made 26 ± 17months after the onset of symptomatology, and an ELST was preoperatively suspected in only six cases. At the time of surgery, 10 patients suffered from hearing loss. Preoperative symptoms or audiometry could not predict labyrinth infiltration, although speech discrimination scores were significantly associated with labyrinth infiltration (p = 0.0413). The labyrinth was infiltrated in 8 cases (57.1%), and in 7 cases (46.7%) the tumor eroded the carotid canal, whereas 6 cases (40%) presented an intradural extension. A gross total resection was achieved in 11 cases. There were two residual tumors, one of which because of profuse bleeding, and one recurrence (23.1%). A mean of 22.8% of recurrent or residual tumors are described in the literature based on 242 published cases, in more than half of the cases as a consequence of subtotal tumor resection (STR). Recurrence derives mostly from the difficulty to identify the extension of the tumor due to the extensive bone infiltration. Accurate diagnosis and correct preoperative planning, with embolization when possible, will facilitate surgery and avoid STR due to intraoperative bleeding. Long follow-ups are important in order to avoid insidious recurrences.

Hybrid antero-lateral transcondylar approach to the clivus: a laboratory investigation and case illustration.

Surgical treatment of lesions involving the ventral craniovertebral junction (CVJ) and the lower clivus, traditionally involved complex lateral or transoral approaches to the skull base. However, mid or upper clivus involvement requires more extensive lateral approaches. Recently, the endoscopic endonasal approach (EEA) has become the standard for upper CVJ lesions and medial clival, and a valuable alternative for those tumors extending in its upper third as well as laterally. However, the EEA is associated with an increased risk of post-operative CSF leakage and infection when the tumor is characterized by an intradural extension. Furthermore, whenever the tumor has significant lateral and/or inferior extension below the odontoid process, the chances for a complete resection decrease. To analyze the extent of exposure of a hybrid microscopic-endoscopic transcondylar antero-lateral approach to the CVJ and clival region, and to verify its effectiveness in terms of mid and upper clival access. Five silicone-injected cadaver heads were used. Following a standard antero-lateral approach, condylectomy and jugular tubercle drilling were performed, after which angled endoscopes were utilized to extend the bone resection to the clivus. A volumetric assessment of the amount of clival removal was carried out. A case of CVJ chordoma operated through this approach is presented. The hybrid antero-lateral transcondylar approach provides adequate exposure of the ventral CVJ, up to the dorsum sellae and the sphenoid sinus, the contralateral petrous apex, and the contralateral paraclival internal carotid artery (ICA). Approximately 60% of the total clival volume can be removed with this approach. The main limitation is the limited visualization of the ipsilateral paraclival ICA and petrous apex. The hybrid antero-lateral transcondylar approach is a valuable surgical option for CVJ tumor extending from C2 to the mid and upper clivus.

A giant lesion extending from prepontine cistern to the fourth ventricle

Because the lesion was adherent to the brainstem, partial resection was performed (Fig. 2), with the help of intraoperative neurophysiological monitoring. Then, pathology revealed chordoma. Chordoma is a rare locally aggressive neoplasm derived from the embryologic notochordal remnants, with incidence of approximately 1/1,000,000 [[1]Persad A.R.L. Mechor B. Starreveld Y. Clival chordoma with brainstem invasion.Can J Neurol Sci. 2018; 45: 235-237Crossref PubMed Scopus (2) Google Scholar]. Chordoma is generally located on the midline including clivus and lumbosacral spine [[2]Walcott B.P. Nahed B.V. Mohyeldin A. Coumans J.V. Kahle K.T. Ferreira M.J. Chordoma: current concepts, management, and future directions.Lancet Oncol. 2012; 13: e69-e76Abstract Full Text Full Text PDF PubMed Scopus (360) Google Scholar]. Symptoms seen with clival chordoma are frequently generated by compression of cranial nerves [[3]Leah P. Dower A. Vescovi C. Mulcahy M. Al Khawaja D. Clinical experience of intracranial chordoma-A systematic review and meta-analysis of the literature.J Clin Neurosci. 2018; 53: 6-12Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar]. Among patients with clival chordoma, intradural extension leading to brainstem compression and extradural extension leading to bony destruction are known phenomena; however, extension from the prepontine cistern to the fourth ventricle is extremely rare. On the preoperative MRI, the clival chordoma mimicks a intra-axial lesion (Fig. 1). Therefore, when MRI shows a neoplasm with severe effacement of the brainstem and similar radiologic features to brainstem tumor, all possibilities including chordoma should be carefully assessed.