Endoscopic Endonasal Surgery for Cranial Base Chondrosarcomas

Surgical management of chondrosarcomas of the skull-base and temporal bone

OBJECTIVES

To analyze the overall long-term outcome of surgically treated skull base and temporal bone chondrosarcomas.

METHODS

The medical records of patients with surgically treated skull base and temporal bone chondrosarcomas between 1983 and 2024 were thoroughly evaluated.

RESULTS

Out of a total of over 5000 skull base surgeries performed at our center, only 29 patients had histopathologically confirmed chondrosarcomas of the skull base and temporal bone. The mean of patients age was 45.6, and the male-to-female ratio was 1.9:1. The most common symptoms included hearing loss (58.6%), tinnitus (41.4%), diplopia (31%), dysphonia (24.1%), dysphagia (20.7%), vertigo (10.3%), and dizziness (10.3%). The most frequent locations of lesions among the 29 patients are as follows: petroclival region (34.5%), jugular foramen (27.6%), petrous apex (17.2%), middle ear (13.8%), others (3.4%). TO, IFTA, IFTB, IFTC, POTS, and combined surgical approaches were commonly used. The rate of gross total removal and recurrence was 82.6% and 13.8% respectively. The follow-up duration of 6 patients was more than five years and less than ten years whereas ten patients had more than ten years of follow-up.

CONCLUSIONS

Chondrosarcoma of the skull base and temporal bone is a very rare pathology. Due to its multiple potential sites of origin and histological specificity, it presents us with significant challenges. Gross total removal is the primary treatment for chondrosarcoma of the skull base and temporal bone. Personalized decision-making should be considered based on the following aspects: tumor, patient, and surgeon's factors. Postoperative radiation therapy is complementary to surgical treatment in grades II and III lesions to achieve long-term survival.

The Endoscopic Transorbital Approach for Vascular Surgery: An Anterior Circulation Anatomic Study, 2-Dimensional Operative Video

BACKGROUND AND OBJECTIVES

Minimally invasive endoscopic approaches in cranial base surgery have been developing in the past decades. The transorbital (TO) route is one promising alternative, yet its adequacy for intracranial vascular lesions remains unclear. The present anatomic work aimed to test the feasibility and to provide a qualitative description of the endoscopic TO approach for the anterior circulation, namely the internal carotid artery and the middle cerebral artery.

METHODS

Seven embalmed adult cadaveric specimens (12 sides) were used in the study. Each side was approached in 3 successive steps: (1) Superior-eyelid TO approach, with great and lesser sphenoid wing removal. (2) Removal of anterior clinoid process (ACP). (3) Removal of the lateral orbital rim. All the procedures were performed under endoscopic view.

RESULTS

The TO approach without removing the ACP allowed to dissect the sphenoidal and lateral segments of the Sylvian fissure with an adequate identification of the middle cerebral artery bifurcation in all specimens. The removal of the ACP allowed further dissection toward the opticocarotid cistern, with the identification of the ophthalmic, posterior communicating, and the anterior choroidal arteries. The internal carotid artery bifurcation and A1 segment were also readily identified. Finally, removal of the lateral orbital rim provided a wider and more comfortable access to the above-mentioned vascular structures.

CONCLUSION

According to our anatomic data, the TO approach can be used to reach the main vascular components of the anterior circulation. This opens the field for exploring its application in the treatment of vascular pathology, particularly aneurysms.

Skull-Base Chondrosarcoma: A Systematic Review of the Role of Postoperative Radiotherapy

Surgery and radiotherapy are key elements to the treatment of skull-base chondrosarcomas; however, there is currently no consensus regarding whether or not adjuvant radiotherapy has to be administered. This study searched the EMBASE, Cochrane, and PubMed databases for clinical studies evaluating the long-term prognosis of surgery with or without adjuvant radiotherapy. After reviewing the search results, a total of 22 articles were selected for this review. A total of 1388 patients were included in this cohort, of which 186 received surgery only. With mean follow-up periods ranging from 39.1 to 86 months, surgical treatment provided progression-free survival (PFS) rates ranging from 83.7 to 92.9% at 3 years, 60.0 to 92.9% at 5 years, and 58.2 to 64.0% at 10 years. Postoperative radiotherapy provides PFS rates ranging between 87 and 96.2% at 3 years, 57.1 and 100% at 5 years, and 67 and 100% at 10 years. Recurrence rates varied from 5.3% to 39.0% in the surgery-only approach and between 1.5% and 42.90% for the postoperative radiotherapy group. When considering prognostic variables, higher age, brainstem/optic apparatus compression, and larger tumor volume prior to radiotherapy were found to be significant factors for local recurrence.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

The impact of expanded endoscopic approaches on oncologic and functional outcomes for clival malignancies:a case series

INTRODUCTION

Clival malignancies pose particular surgical challenges due to complex skull base anatomy and the involvement of vital neurovascular structures. While endoscopic endonasal approached are widely used, the outcomes for clival malignancies remain poorly understood. In this study we assessed the impact of endoscopic and open surgical approaches on PFS, time to initiation of radiotherapy, KPS, and GTR rates for clival malignancies.

METHODS

A retrospective case series for clival malignancies operated between 1993 and 2019 was conducted. Inclusion criteria were age over 18 and a follow-up of at least a 6 months. Statistical analyses were conducted using STATA version 15 statistical software package StataCorp.

RESULTS

For the whole cohort (113 patients), and for upper and middle lesions, open surgical approaches increased odds of disease progression, compared to EEA (HR 2.10 to HR 2.43), p < 0.05. EEA had a shorter time interval from surgery to initiation of radiotherapy. No difference in 6 and 12 month KPS was found between surgical groups. Patients undergoing open surgery were less likely to achieve GTR for upper clival lesions.

CONCLUSIONS

EEA was found to be associated with increased PFS, for upper and middle clival malignancies. The time to initiation of radiotherapy was shorter for patients undergoing EEA compared to open surgery for patients with middle clival involvement. GTR rates were found to be significantly better with EEA for patients with upper clival malignancies.

Localisation of the petrous internal carotid artery relative to the vidian canal on computed tomography: a case-control study evaluating the impact of petroclival chondrosarcoma

Background

The vidian canal (VC) is normally a reliable anatomical landmark for locating the petrous internal carotid artery (pICA). This study determined the influence of petroclival chondrosarcoma on the relationship between the VC and pICA.

Methods

Nine patients (3 males, 6 females; median age 49) with petroclival chondrosarcoma, and depiction of the pICA on contrast-enhanced CT, were retrospectively studied. CT-based measurements were performed by two observers, both in the presence of the petroclival chondrosarcoma (case) and on the contralateral control side. The antero-posterior (AP) and craniocaudal (CC) measurements from the posterior VC to the pICA, whether the pICA was in the trajectory of the VC, and the coronal relationship of the pICA anterior genu with the VC were recorded.

Results

Chondrosarcoma usually displaced the pICA anteriorly (8/9 cases) and superiorly (6/9 cases) relative to the normal side with mean AP and CC measurements of 3.9 mm v 7.2 mm (p = 0.054) and 4.4 mm v 1.4 mm (p = 0.061). The VC trajectory less frequently intersected the pICA cross-section in the presence of chondrosarcoma however it was in the line of the eroded dorsal VC in one case. The anterior genu of the pICA was displaced more laterally by chondrosarcoma but usually remained superior to the VC.

Conclusion

Petroclival chondrosarcoma variably influences the anatomical relationship between the VC and the pICA, hence requiring an individualised approach. The pICA is usually anterosuperiorly displaced, and the anterior genu remains superior to the VC, however it may be located in the line of the canal.

Petrous bone lesions: surgical implementation and outcomes of extradural subtemporal approach

BACKGROUND

Petrous bone lesions (PBLs) are rare with few reports in the neurosurgical literature. In this study, the authors describe our current technique of extradural subtemporal approach (ESTA). The objective of this study was to evaluate the role and efficacy of ESTA for treatment of the PBLs. To our knowledge, this is the largest reported clinical series of using an ESTA-treated PBLs in which the clinical outcomes were evaluated.

METHODS

Between 1994 and 2019, 67 patients with PBLs treated by ESTA were retrospectively reviewed. Extent of resection, neurological outcomes, recurrence rate, and surgical complications were evaluated and compared with previous studies. The indications, advantages, limitations, and outcomes of ESTA were analyzed according to pathology.

RESULTS

This series included 7 facial nerve schwannomas (10.4%), 16 cholesterol granulomas (23.9%), 16 chordomas (23.9%), 6 chondrosarcomas (9%), 5 trigeminal schwannomas (7.5%), 9 epidermoids/dermoids (13.4%), and 8 other pathologies (11.9%). The most common location of PBLs operated with ESTA was at the petrous apex and rhomboid areas (68.7%). Gross total resection was achieved in 35 (55.6%). Symptomatic improvement occurred in 56 patients (83.6%). Complications occurred in 7 (10.4%) of cases including one mortality. Nine patients (17%) had recurrence within the mean follow-up 71 months. Compared to previous literature, our results demonstrated comparable outcomes but with higher rates of hearing and facial nerve preservation as well as minimal morbidity. From our results, ESTA is an effective therapeutic option for lesions located at the rhomboid and petrous apex, particularly when patients presented with intact facial and hearing function.

CONCLUSION

Our series demonstrated that ESTA provided satisfactory outcomes with excellent benefits of hearing and facial function preservation for patients with petrous bone lesions. ESTA should be considered as a safe and effective therapeutic option for selected patients with PBLs.

Neurosurgical management of petrous bone lesions: classification system and selection of surgical approaches

BACKGROUND

Surgery of petrous bone lesions (PBLs) is challenging for neurosurgeons. Selection of the surgical approach is an important key for success. In this study, the authors present an anatomical classification for PBLs that has been used by our group for over the past 26 years. The objective of this study is to investigate the benefits and applicability of this classification.

METHODS

Between 1994 and 2019, 117 patients treated for PBLs were retrospectively reviewed. Using the V3 and arcuate eminence as reference points, the petrous bone is segmented into 3 parts: petrous apex, rhomboid, and posterior. The pathological diagnoses, selection of the operative approach, and the extent of resection (EOR) were analyzed and correlated using this classification.

RESULTS

This series included 22 facial nerve schwannomas (18.8%), 22 cholesterol granulomas (18.8%), 39 chordomas/chondrosarcomas (33.3%), 6 trigeminal schwannomas (5.1%), 13 epidermoids/dermoids (11.1%), and 15 other pathologies (12.8%). PBLs were most often involved with the petrous apex and rhomboid areas (46.2%). The extradural subtemporal approach (ESTA) was most frequently used (57.3%). Gross total resection was achieved in 58.4%. Symptomatic improvement occurred in 92 patients (78.6%). Our results demonstrated a correlation between this classification with each type of pathology (p < .001), selection of surgical approaches (p < 0.001), and EOR (p = 0.008). Chordoma/chondrosarcoma, redo operations, and lesions located medially were less likely to have total resection. Temporary complications occurred in 8 cases (6.8%), persistent morbidity in 5 cases (4.3%), and mortality in 1 case.

CONCLUSION

In this study, we proposed a simple classification of PBLs. Using landmarks on the superior petrosal surface, the petrous bone is divided into 3 parts, apex, rhomboid, and posterior. Our results demonstrated that chordoma/chondrosarcoma, redo operations, and lesions involving the tip of the petrous apex or far medial locations were more difficult to achieve total resection. This classification could help surgeons understand surgical anatomy framework, predict possible structures at risk, and select the most appropriate approach for each patient.

Additive Manufacturing for Personalized Skull Base Reconstruction in Endoscopic Transclival Surgery: A Proof-of-Concept Study

BACKGROUND

Endoscopic transnasal transclival intradural surgery is limited by a high postoperative cerebrospinal fluid leak rate. The aim of this study was to investigate the role of three-dimensional printing to create a personalized, rigid scaffold for clival reconstruction.

METHODS

Two different types of clivectomy were performed in 5 specimens with the aid of neuronavigation, and 11 clival reconstructions were simulated. They were repaired with polylactide, three-dimensional-printed scaffolds that were manually designed in a computer-aided environment based either on the real or on the predicted defect. Scaffolds were printed with a fused filament fabrication technique and different offsets. They were positioned and fixed either following the gasket seal technique or with screws. Postdissection radiological evaluation of scaffold position was performed in all cases. In 3 specimens, the cerebrospinal fluid leak pressure point was measured immediately after reconstruction.

RESULTS

The production process took approximately 30 hours. The designed scaffolds were satisfactory when no offset was added. Wings were added during the design to allow for screw positioning, but broke in 30% of cases. Radiological assessment documented maximal accuracy of scaffold positioning when the scaffold was created on the real defect; accuracy was satisfactory when the predicted clivectomy was performed under neuronavigation guidance. The cerebrospinal fluid leak pressure point was significantly higher when the scaffold was fixed with screws compared with the gasket technique.

CONCLUSIONS

In this preclinical setting, additive manufacturing allows the creation of customized scaffolds that are effective in reconstructing even large and geometrically complex clival defects.

Long-term outcomes of grade I/II skull base chondrosarcoma: an insight into the role of surgery and upfront radiotherapy

PURPOSE

To clarify the need for post-operative radiation treatment in skull base chondrosarcomas (SBCs).

METHODS

A retrospective analysis of patients with grade I or II SBC. Patients were divided according to post-surgical treatment strategies: (A) planned upfront radiotherapy and (B) watchful waiting. Tumor control and survival were compared between the treatment groups. The median follow-up after resection was 105 months (range, 9-376).

RESULTS

Thirty-two patients (Grade 1, n = 16; Grade 2, n = 16) were included. The most frequent location was petroclival (21, 64%). A gross total resection (GTR) was achieved in 11 patients (34%). Fourteen (44%) underwent upfront radiotherapy (group A) whereas 18 (56%) were followed with serial MRI alone (group B). The tumor control rate for the entire group was 77% and 69% at 10- and 15-year, respectively. Upfront radiotherapy (P = 0.25), extent of resection (P = 0.11) or tumor grade (P = 0.83) did not affect tumor control. The majority of Group B patients with recurrent tumors (5/7) obtained tumor control with repeat resection (n = 2), salvage radiotherapy (n = 2), or a combination of both (n = 1). The 10-year disease-specific survival was 95% with no difference between the group A and B (P = 0.50).

CONCLUSION

For patients with grade I/II SBC, a reasonable strategy is deferral of radiotherapy after maximum safe resection until tumor progression or recurrence. At that time, most patients can be successfully managed with salvage radiotherapy or surgery. Late recurrences may occur, and life-long follow-up is advisable.

A preoperative risk classifier that predicts tumor progression in patients with cranial base chondrosarcomas

OBJECTIVE

The authors conducted a study to identify clinical features of cranial base chondrosarcomas that will predict tumor progression after resection.

METHODS

The authors performed a retrospective study at a tertiary referral cranial base center. Patients who underwent resection of cranial base chondrosarcomas between January 2004 and December 2018 were followed longitudinally. The main outcome measure was progression-free survival (PFS).

RESULTS

A total of 41 patients were treated for histopathologically proven "conventional" cranial base chondrosarcomas during the study period, and the median PFS was 123 months for the cohort. Univariate analysis was performed on clinical, anatomical, and radiographic parameters collected for each patient. Features that were statistically significant were fed into a multivariate regression model, which revealed two independent predictors of PFS: patient age and encasement of 3-4 major arteries (> 25% of the vessel wall surrounded by tumor). Using these two variables of age and multiple arterial vessel encasement, the authors generated a risk stratification model using a simple point system to predict PFS in patients with cranial base chondrosarcomas. Based on these two factors known preoperatively, this model could stratify patients into high-risk (10% of patients), intermediate-risk (68% of patients), and low-risk (22% of patients) subgroups corresponding to dramatically distinct median PFS (1.8 years, 10.2 years, and no progression, respectively).

CONCLUSIONS

In patients with cranial base chondrosarcomas, age and artery encasement are variables known preoperatively that can powerfully predict tumor progression, define operative goals, and aid in selecting postoperative adjuvant therapy.

Facing a Feared Situation: Endoscopic Endonasal Approach for Petroclival Lesions With Internal Carotid Artery Encasement: 2-Dimensional Operative Video

A 33-yr-old woman presented with diplopia due to partial III and VI cranial nerve palsies, and an magnetic resonance imaging (MRI) showed a left petroclival lesion with cavernous sinus invasion. The ipsilateral internal carotid artery (ICA) was displaced and encased by the tumor. Chondroid tumors such as this are known to be high risk for ICA injury1; however, given the patient's young age a radical resection was desirable,2 depending on the risk of such a strategy. Therefore, a preoperative balloon test occlusion (BTO) was performed to estimate the risk of stroke in case of ICA sacrifice.3 Clinical and single-photon emission computed tomography testing predicted low risk of stroke, allowing for aggressive resection. A preoperative ICA occlusion was not performed as intraoperative control was believed to be adequate and preservation is always preferable when possible due to rare inaccuracies in BTO and long term risks of occlusion. An endoscopic endonasal and right contralateral transmaxillary approach with intraoperative neurophysiology were performed to remove this lesion.4,5 During surgery, the ICA proved dehiscent, and was therefore clip sacrificed.6 An immediate postoperative digital subtraction angiography showed minimally delayed, but adequate, blood flow to the left cerebral hemisphere. Postoperative MRI showed complete removal and no significant infarct. The patient was discharged in stable neurological condition, with only a slightly worsened CN III palsy. Experience with management of ICA injury is of uttermost importance in endoscopic endonasal surgery,1,2 and requires adequate training and an experienced 2-surgeon team.7 The patient provided consent to the submission and publication of the related surgical video.

Can Ophthalmologic Examination Predict Abducens Nerve Recovery After Endoscopic Skull Base Surgery?

OBJECTIVES

While abducens nerve palsy (ANP) is a known risk in the setting of some endoscopic endonasal skull base surgery (ESBS), frequency and prognosis of post-operative palsy remain unknown. Our goals were to determine the frequency and prognosis of ANP after high-risk ESBS, and identify factors associated with recovery.

METHODS

Retrospective case series of all patients with pathology at highest risk for abducens nerve injury (pituitary adenoma, chordoma, meningioma, chondrosarcoma, cholesterol granuloma) generated a list of patients with abducens nerve palsy after ESBS performed from 2011-2016. A validated ophthalmologic clinical grading scale measuring lateral rectus duction from 0 to -5 (full motion to inability to reach midline) was measured at multiple time points to assess recovery of ANP.

RESULTS

Of 655 patients who underwent ESBS with increased risk of abducens injury, 40 (6.1%) post-operative palsies were identified and 39 patients with dedicated examination at multiple time points were included in subsequent analysis. Complete resolution was noted in 25 patients (64%) within 12 months. While 19 of 23 (83%) with a partial palsy had complete resolution, only six of 16 (38%) with a complete palsy resolved entirely (P = .005; Fisher's exact test). All six patients with delayed onset of palsy resolved (P = .070; Fisher's exact test). Meningioma and chordoma had higher rates of both temporary and permanent post-operative ANP (P < .0001; Fisher's exact).

CONCLUSIONS

The frequency of post-operative ANP following ESBS is low, even in high-risk tumors. While only a minority of complete abducens nerve palsies recover, patients with partial or delayed palsy post-operatively are likely to recover function without intervention.

LEVEL OF EVIDENCE

IV Laryngoscope, 131:513-517, 2021.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Endoscopic endonasal transpterygoid transnasopharyngeal management of petroclival chondrosarcomas without medial extension

Chondrosarcomas of the skull base are malignant tumors for which surgery is the primary therapeutic option. Gross-total resection has been demonstrated to improve survival in patients with these tumors. Chondrosarcomas arising from the petroclival synchondrosis harbor particularly unique anatomical considerations that have long been a barrier to achieving such a resection. Endoscopic endonasal transpterygoid approaches have been recently used to gain improved access to such lesions; however, these approaches have classically relied on a medial to lateral transclival trajectory, which provides limited exposure for complete resection of lateral disease. In this paper the authors describe an endoscopic endonasal transpterygoid transnasopharyngeal approach that provides comprehensive access to the petroclival region through dissection of the eustachian tube with resection of the cartilaginous torus tubarius. Of note, the authors have previously demonstrated the superior outcomes and validity of this approach relative to other cranial base techniques for petroclival chondrosarcomas. Surgical outcomes in 5 cases of chondrosarcoma without medial extension are detailed. Gross-total resection was achieved in 4 of 5 patients. Postoperative complications included transient palatal numbness in all patients and eustachian tube dysfunction due to the approach. With tympanostomy tube placement, no patient had persistent hearing loss. Overall, this approach appears to be a safe and effective technique for resection of petroclival chondrosarcomas.

The medial wall of the cavernous sinus. Part 2: Selective medial wall resection in 50 pituitary adenoma patients

OBJECTIVE

Pituitary adenomas often invade the medial wall of the cavernous sinus (CS), but this structure is generally not surgically removed because of the risk of vascular and cranial nerve injury. The purpose of this study was to report the surgical outcomes in a large series of cases of invasive pituitary adenoma in which the medial wall of the CS was selectively removed following an anatomically based, stepwise surgical technique.

METHODS

The authors' institutional database was reviewed to identify cases of pituitary adenoma with isolated invasion of the medial wall, based on an intraoperative evaluation, in which patients underwent an endoscopic endonasal approach with selective resection of the medial wall of the CS. Cases with CS invasion beyond the medial wall were excluded. Patient complications, resection, and remission rates were assessed.

RESULTS

Fifty patients were eligible for this study, 15 (30%) with nonfunctional adenomas and 35 (70%) with functional adenomas, including 16 growth hormone-, 10 prolactin-, and 9 adrenocorticotropic hormone (ACTH)-secreting tumors. The average tumor size was 2.3 cm for nonfunctional and 1.3 cm for functional adenomas. Radiographically, 11 cases (22%) were Knosp grade 1, 23 (46%) Knosp grade 2, and 16 (32%) Knosp grade 3. Complete tumor resection, based on intraoperative impression and postoperative MRI, was achieved in all cases. The mean follow-up was 30 months (range 4-64 months) for patients with functional adenomas and 16 months (range 4-30 months) for those with nonfunctional adenomas. At last follow-up, complete biochemical remission (using current criteria) without adjuvant treatment was seen in 34 cases (97%) of functional adenoma. No imaging recurrences were seen in patients who had nonfunctional adenomas. A total of 57 medial walls were removed in 50 patients. Medial wall invasion was histologically confirmed in 93% of nonfunctional adenomas and 83% of functional adenomas. There were no deaths or internal carotid artery injuries, and the average blood loss was 378 ml. Four patients (8%) developed a new, transient cranial nerve palsy, and 2 of these patients required reoperation for blood clot evacuation and fat graft removal. There were no permanent cranial nerve palsies.

CONCLUSIONS

The medial wall of the CS can be removed safely and effectively, with minimal morbidity and excellent resection and remission rates. Further follow-up is needed to determine the long-term results of this anatomically based technique, which should only be performed by very experienced endonasal skull base teams.

[Extended endoscopic endonasal surgery for clival chordoma and chondrosarcoma: Our experience in 14 cases]

OBJECTIVE

To report our experience in the management of chordoma and chondrosarcoma with extended endoscopic endonasal surgery.

METHOD

We performed a retrospective analysis of a series of 14 patients with clival chordoma or chondrosarcoma who had extended endoscopic endonasal surgery from 2008 to 2016 performed by the same multidisciplinary team.

RESULTS

We had fourteen patients (male/female 2:1), with a mean age of 49years for chordoma and 32 for chondrosarcoma. The most common clinical presentation was diplopia in 78.5% of cases, followed by dysphagia in 28.6%. Histologically, 71.4% were chordomas and 28.6% were chondrosarcomas. In addition, invasion of at least two thirds or more of the clivus was found in 81% of the cases; in 57.1% there was intradural invasion, and in 35.7% invasion of the sella turcica. In 42.8% of cases, the degree of resection was total and in 21.5% subtotal. The most common complication was CSF fistula, occurring in 28.6% of the cases, with only one case requiring surgery to repair it. Adjuvant treatment with Proton Beam was performed in 35.7% of cases and with conventional radiotherapy in 21.5%. Mean follow-up was 53.5months and tumour recurrence or progression was found in 21.5% of the cases, two of which had not received adjuvant treatment. There were no deaths.

CONCLUSION

The extended endoscopic endonasal approach (EEEA) performed by an experienced team is a good alternative for the management of these lesions. Intradural invasion may be related to an increased risk of complications and worse clinical presentation, in addition to a lower rate of total resection.