Endoscopic Endonasal Transclival Research Articles

Supratotal Resection of Residual Clival Chordoma With Combined Endoscopic Endonasal and Contralateral Transmaxillary Approaches: 2-Dimensional Operative Video.

The optimal treatment for skull base chordomas is gross total resection followed by radiotherapy and not radiation of partially resected tumors. Supratotal resection, defined as removal beyond all involved bone and dura, is ideal but difficult to achieve. In this video, we present the case of a 37-yr-old man with new onset of progressive cranial nerve sixth palsy and a skull base lesion compatible with clival chordoma. He underwent partial surgical resection at an outside institution via transcranial approach, with significant tumor residual at the clivus, dorsum sella, posterior clinoids, and petrous apex, extensive dural invasion, and intradural extension with attachment to the basilar artery and its long perforating branches. Supratotal surgical resection was achieved using an endoscopic endonasal transclival approach, ipsilateral transpteryoid approach to the foramen lacerum for carotid artery mobilization, bilateral interdural transcavernous approach with posterior clinoidectomies, and con-tralateral transmaxillary approach to the petrous apex. Reconstruction was performed in a multilayer fashion with fascia lata and fat grafts, extended nasoseptal flap, a lumbar drainage for 3 d. No cerebrospinal fluid leak occurred, and the abducens nerve palsy significantly improved at 3-mo follow-up. Proton therapy is planned. Recent advances in endoscopic endonasal surgery allow for very high rates of complete and even supratotal resection despite the challenging location. A long learning curve to acquire the technical skills and complex surgical anatomy is required to decrease complication rates and achieve maximal resection in chordomas. Reoperations are more challenging and risky; therefore, first attempt should have curative intent. The patient signed informed consent including the use of photographic and video material for educational or academic purposes.

Endoscopic Endonasal Transclival Approach to the Ventral Brainstem: Anatomic Study of the Safe Entry Zones Combining Fiber Dissection Technique with 7 Tesla Magnetic Resonance Guided Neuronavigation.

Treatment of intrinsic lesions of the ventral brainstem is a surgical challenge that requires complex skull base antero- and posterolateral approaches. More recently, endoscopic endonasal transclival approach (EETA) has been reported in the treatment of selected ventral brainstem lesions. In this study we explored the endoscopic ventral brainstem anatomy with the aim to describe the degree of exposure of the ventral safe entry zones. In addition, we used a newly developed method combining traditional white matter dissection with high-resolution 7T magnetic resonance imaging (MRI) of the same specimen coregistered using a neuronavigation system. Eight fresh-frozen latex-injected cadaver heads underwent EETA. Additional 8 formalin-fixed brainstems were dissected using Klingler technique guided by ultra-high resolution MRI. The EETA allows a wide exposure of different safe entry zones located on the ventral brainstem: the exposure of perioculomotor zone requires pituitary transposition and can be hindered by superior cerebellar artery. The peritrigeminal zone was barely visible and its exposure required an extradural anterior petrosectomy. The anterolateral sulcus of the medulla was visible in most of specimens, although its close relationship with the corticospinal tract makes it suboptimal as an entry point for intrinsic lesions. In all cases, the use of 7T-MRI allowed the identification of tiny fiber bundles, improving the quality of the dissection. Exposure of the ventral brainstem with EETA requires mastering surgical maneuvers, including pituitary transposition and extradural petrosectomy. The correlation of fiber dissection with 7T-MRI neuronavigation significantly improves the understanding of the brainstem anatomy.

Endoscopic endonasal transclival resection of a “pontine chordoma”: Technical case report

Abstract Clival chordomas represent very challenging neoplasms, due to their tendency to infiltrate bone, frequent recurrence, involvement of important neurovascular structures, and deep location. Lesions involving the brainstem remain difficult to access through conventional skull-base approaches which are often associated with significant morbidities. We present a successful purely endoscopic endonasal transclival resection of a rare chordoma located in the ventromedial pons. Recent advances in endoscopic technology make endoscopic endonasal approach (EEA) a possible alternative to the treatment of ventral brainstem lesions.

Endoscopic endonasal transclival removal of tumors of the clivus and anterior region of the posterior cranial fossa (results of surgical treatment of 140 patients)

BackgroundUntil recently, tumors of the clivus and the anterior region of the posterior cranial fossa were considered extremely difficult to access and often inoperable using standard transcranial approaches. With the introduction into the neurosurgical practice of minimally invasive methods utilizing endoscopic techniques, it became possible to effectively remove hard-to-reach tumors, including central tumors of the anterior region of the posterior cranial fossa.MethodsFrom 2008 to the present time, the inpatient institution has operated on 140 patients with various tumors of the base of the skull, localized to the clivus and anterior region of the posterior cranial fossa (65 men and 75 women). The age of patients ranged from 3 to 74 years. Tumor distribution according to the histopathological features was as follows: chordomas, 103 (73.57%); meningiomas, 12 (8.57%); pituitary adenomas, 9 (6.43%); fibrous dysplasia, 4 (2.86%); cholesteatoma, 3 (2.14%); craniopharyngiomas, 2 (1.43%); plasmacytomas, 2 (1.43%); and other tumors (giant cell tumor, neurohypophyseal glioma, osteoma, carcinoid, chondroma), 5 (3.57%). The tumors had the following size distribution: giant (more than 60 mm), 35 (25%); large (35–59 mm), 83 (59.3%); medium (21–35 mm), 21 (15%); and small (less than 20 mm), 1 (0.7%). In 11 cases, intraoperative monitoring of the cranial nerves was performed (21 cranial nerves were identified).ResultsUpper, middle, and lower transclival approaches provide access to the anterior surface of the upper, middle, and lower neurovascular complexes of the posterior cranial fossa. The chordoma cases were distributed as follows according to extent of removal: total removal, 68 (66.02%); subtotal removal, 25 (24.27%); and partial removal, 10 (9.71%). The adenomas of the pituitary gland were removed totally in 6 cases, subtotally in 1 case and partially in 2 cases. The meningiomas were removed totally in 1 case, subtotally in 5 cases, and partially in 5 cases, with less than 50% of the tumor removed in 1 case. Other tumors (cholesteatoma, craniopharyngioma, fibrous dysplasia, giant cell tumor, glioma of the neurohypophysis, osteoma, plasmacytoma, carcinoid, and chondroma) were removed totally in 9 cases and subtotally in 7 cases. Postoperative CSF leaks occurred in 9 cases (6.43%) and meningitis in 13 cases (9.29%). Oculomotor disorders developed in 19 patients (13.57%), 12 of which regressed during the period from 4 to 38 days after surgery, and 7 of which were permanent. In 2 cases, surgical treatment had a lethal outcome (1.43%).ConclusionThe endoscopic endonasal transclival approach can be used to obtain access to the centrally located tumors of the posterior cranial fossa. It is an alternative to transcranial approaches in the surgical treatment of tumors of the clivus. The results of using this approach are comparable with the results of transcranial and transfacial approaches and, in some cases, surpass them in effectiveness. The extended endoscopic endonasal posterior (transclival) approach, considering its minimally invasive nature, allows fora radical and low-risk (in terms of postoperative complications and lethality) removal of various skull base tumors of central localization with the involvement and without the involvement of the clivus, which, until recently, were considered to be almost inoperable.

Endoscopic Endonasal Transclival Approach for Resection of a Pontine Glioma: Surgical Planning, Surgical Anatomy, and Technique.

The endoscopic endonasal approach (EEA) has been proposed as a potential alternative for ventral brainstem lesions. The surgical anatomy, feasibility, and limitations of the EEA for intrinsic brainstem lesions are still poorly understood. To describe the surgical planning, anatomy, and technique of an intrinsic pontine glioma operated via EEA. Six-human brainstems were prepared for white matter microdissection. Ten healthy subjects were studied with high-definition fiber tractography (HDFT). A 56-yr-old female with right-hemiparesis underwent EEA for an exophytic pontine glioma. Pre- and postoperative HDFTs were implemented. The corticospinal tracts (CSTs) are the most eloquent fibers in the ventral brainstem. At the pons, CSTs run between the pontine nuclei and the middle cerebellar peduncle (MCP). At the lower medulla, the pyramidal decussation leaves no room for safe ventral access. In our illustrative case, preoperative HDFT showed left-CST displaced posteromedially and partially disrupted, right-CST posteriorly displaced, and MCP severely disrupted. A transclival exposure was performed achieving a complete resection of the exophytic component with residual intra-axial tumor. Immediately postop, patient developed new left-side abducens nerve palsy and worse right-hemiparesis. Ten days postop, her strength returned to baseline. HDFT showed preservation and trajectory restoration of the CSTs. The EEA provides direct access to the ventral brainstem, overcoming the limitations of lateral approaches. For intrinsic pathology, HDFT helps choosing the most appropriate surgical route/boundaries for safer resection. Further experience is needed to determine the indications and limitations of this approach that should be performed by neurosurgeons with high-level expertise in EEA.

Endoscopic Endonasal Transclival Approach to Tumors of the Clivus and Anterior Region of the Posterior Cranial Fossa (Results of Surgical Treatment of 136 Patients)

With the introduction into the neurosurgical practice of minimally invasive methods using endoscopic techniques, it became possible to effectively remove hard-to-reach tumors, including central tumors of the anterior region of the posterior cranial fossa. To analyze the results of surgical treatment of patients with various centrally located tumors of the base of the skull that extend into the anterior region of the posterior cranial fossa using the endoscopic endonasal transclival approach. The personal surgical experience of the first author is 136 patients with various tumors (e.g., chordomas, meningiomas, pituitary adenomas, and fibrous dysplasia). Radicality of tumor removal was total 61.03%; subtotal 25%; partial 13.23%; and insufficient removal 0.74%. Postoperative cerebrospinal fluid leaks occurred in 9 cases (6.62%) and meningitis in 13 cases (9.56%). In 2 cases, surgical treatment had a lethal outcome (1.47%). The endoscopic endonasal transclival approach can be used to obtain access to centrally located skull base tumors. This approach allows for a radical and low-risk removal of various skull base tumors of central localization that, until recently, were considered to be almost inoperable.

Endoscopic Endonasal Transclival Approach to Tumors of the Clivus and Anterior Region of the Posterior Cranial Fossa: An Anatomic Study

To present the basic topographic and anatomic features of the clivus and adjacent structures with an objective of possible improvements and optimization of the extended endoscopic endonasal posterior (transclival) approach when removing tumors of the clivus and anterior regions of the posterior cranial fossa. A craniometric study was conducted on 125 human skulls. A topographic anatomic study was conducted on 25 cadaver head specimens with arterial and venous beds stained with colored silicone, according to the method developed by us, to visualize its features and individual variability. The most important anatomic features of the external and internal regions of the clivus and the adjacent neural and vascular structures were analyzed. An accessible zone for the most effective transclival approach to the posterior cranial fossa is also specified. The endoscopic endonasal transclival approach can be used to obtain access to centrally located tumors of the posterior cranial fossa. It is an alternative to transcranial approaches in the surgical treatment of tumors of the clivus.

P.053 Expanded endoscopic endonasal approach for petrous apex lesions: our clinical experience and surgical techniques

Background: Traditionally petrous apex lesions surgical approach is associated with multiple complications including brain injury secondary to brain retraction. Expanded endoscopic endonasal trans-clival (EEET) can be used in selected patients with minimal complications. Methods: We are presenting our experience over the last three years in patients who underwent EEET resection of petrous apex lesions: 8 patients underwent such procedure. All patients underwent extensive workup including MRI and CTA to identify the relation of the carotid to the lesion. All surgeries were done with neuro-physiological monitoring. Intraoperative neuronavigation and endoscopic Doppler were used to identify the petrous segment of the internal carotid artery. Our follow up ranged from 6 months to 2.5 years. Results: All patients presented with severe neurologic symptoms related to either fifth cranial nerve, sixth cranial nerve or brain stem compression. Pathologies included chondrosarcoma, cholesterol granulomas and lymphangioma. All patients demonstrated improvement in their symptoms. None of our patients had intra-operative vascular injury. There was no post-operative CSF leak or infection. Postoperative imaging demonstrated excellent resection with no clear residual. Three patient required adjuvant stereotactic radiosurgery because of their underlying pathology. Conclusions: The expanded endoscopic endonasal approach for petrous apex lesion should be considered as a minimally invasive approach in selected cases.

The limits of the endoscopic endonasal transclival approach for posterior fossa tumors

Endoscopic endonasal approaches (EEA) have gained popularity and acceptance in skull base surgery over the last two decades. So-called expanded EEA allow access in the sagittal plane from the frontal sinus to the odontoid process. The endoscopic endonasal transclival approach allows a unique trajectory into the midline clivus and skull base that is unachievable from traditional craniotomy approaches to lesions such as chondrosarcomas, chordomas, and posterior fossa meningiomas. In this review, we will assess the benefits and drawbacks to using an endoscopic endonasal approach versus transcranial approach to these challenging lesions, assess the anatomical limits of endoscopic endonasal transclival surgery, and discuss the published literature on the topic.

Endoscopic Endonasal Transclival Removal of Mid Located Skull Base Tumors that Spread to the Posterior Cranial Fossa

Endoscopic Endonasal Transclival Removal of Mid Located Skull Base Tumors that Spread to the Posterior Cranial Fossa

Endoscopic Endonasal Approach for Transclival Resection of a Petroclival Meningioma: A Technical Note.

The endoscopic endonasal transclival approach has been widely described for its use to resect clivus chordomas, but there have only been isolated reports of its use for petroclival meningiomas. These tumors are most often resected utilizing open transpetrosal approaches, but these operations, difficult even in the hands of dedicated skull base surgeons, are particularly challenging if the meningiomas are medially-situated and positioned mainly behind the clivus. For this subset of petroclival meningiomas, a transclival approach may be preferable. We report a meningioma resected via an endoscopic endonasal transclival technique. The patient was a 63-year-old man who presented originally for medical attention because of diplopia related to an abducens palsy on the left. A workup at that time revealed a meningioma contained entirely in the left cavernous sinus, and this was treated with stereotactic radiosurgery. His symptoms resolved and his meningioma was stable on MRI for several years after treatment. The patient was then lost to follow-up until 13 years after radiosurgery when he experienced intermittent diplopia again. At this point, workup revealed a large petroclival meningioma compressing the brainstem. He underwent a successful endoscopic endonasal transclival resection of this tumor. A demonstration of the step-by-step surgical technique, discussion of the nuances of the operation, and a comparison with the open transpetrosal approaches are included in our report.

Variations of mucosal-sparing septectomy for endonasal approach to the craniocervical junction.

Recent advances in surgical techniques have rendered the craniocervical junction (CCJ) accessible transnasally. Endoscopic endonasal transclival and transodontoid approaches are routinely performed in leading skull base centers. Usually, these approaches involve a posterior bony and mucosal septectomy, which may compromise the vascularized pedicled nasoseptal flap (PNSF), a robust reconstructive option for repair of large skull base defects. With the possibility of an intraoperative cerebrospinal fluid leak and the reported success of the PNSF for repair of these defects, preserving the integrity of the PNSF is beneficial during the endoscopic endonasal approach to the CCJ. We describe three new variations/refinements of the endoscopic endonasal approach to the CCJ that preserve the mucosal integrity of the posterior nasal septum and PNSF. Photo and video documentation of cadaveric dissections. The steps required for the different variations in approaching the CCJ are demonstrated. These three options are: 1) nonopposing Killian incisions with submucosal elevation of PNSFs laterally under the inferior turbinates (the PNSFs are retracted laterally and left attached superiorly onto the nasal septum and laterally under the inferior turbinate); 2) bilateral non-opposing PNSFs tucked beneath their respective middle turbinate or into the sphenoid sinus; and 3) a hybrid approach combining option 1 performed on one side and option 2 on the contralateral side. All three options allowed for a mucosal-sparing septectomy to provide ample access to the CCJ. These variations/refinements of the mucosal-sparing approach to the CCJ allowed adequate surgical access with sufficient maneuverability while preserving both PNSFs. NA. Laryngoscope, 126:2220-2225, 2016.

Assessment of the Endoscopic Endonasal Transclival Approach for Surgical Clipping of Anterior Pontine Anterior-Inferior Cerebellar Artery Aneurysms

Aneurysms of the anterior pontine segment of the anterior-inferior cerebellar artery (AICA) are uncommon. Their treatment is challenging because critical neurovascular structures are adjacent to it and the available surgical corridors are narrow and deep. Although endoscopic endonasal approaches are accepted for treating midline skull base lesions, their role in the treatment vascular lesions remains undefined. The present study is aimed to assess the anatomic feasibility of the endoscopic endonasal transclival (EET) approach for treating anterior pontine AICA aneurysms and compare it with the subtemporal anterior transpetrosal (SAT) approach. Twelve cadaveric specimens were prepared for surgical simulation. The AICAs were exposed using both EET and SAT approaches. Surgical window area and the length of the exposed artery were measured. The distance from the origin of the artery to the clip applied for proximal control was measured. The number of AICA perforators exposed and the anatomic features of each AICA were recorded. The EET approach provided a wider surgical window area compared with the SAT (P < 0.001). More AICA perforators were visualized using the EET approach (P < 0.05). To obtain proximal control of the AICA, an aneurysm clip could be applied closer to the origin of AICA using EET (0.2 ± 0.42 mm) compared with SAT (6.26 ± 3.4 mm) (P < 0.001). Clipping anterior pontine AICA aneurysms using the EET approach is feasible. Compared with SAT, the EET approach provides advantages in surgical window area, ensuring proximal control before aneurysm dissection, visualization of perforating branches, and better proximal control.

Using the Endoscopic Endonasal Transclival Approach to Access Aneurysms Arising from AICA, PICA, and Vertebral Artery: An Anatomical Study

Using the Endoscopic Endonasal Transclival Approach to Access Aneurysms Arising from AICA, PICA, and Vertebral Artery: An Anatomical Study

A New Window for the Treatment of Posterior Cerebral Artery, Superior Cerebellar Artery, and Basilar Apex Aneurysm: The Expanded Endoscopic Endonasal Approach.

To explore the feasibility of an endoscopic endonasal transclival approach to treat aneurysms arising in the basilar apex, posterior cerebral arteries, and superior cerebellar arteries. Cadaveric anatomical study. Fifteen cadaveric specimens. Degree of surgical exposure of each artery attained, distance from the nasal vestibule to these three arteries, and feasibility of clipping these vessels using standard vascular clip applicators. Both posterior cerebral arteries were exposed, 0.67 cm (standard deviation [SD]: 0.2) on the right side and 0.59 cm (SD: 0.2) on the left side. Both right and left superior cerebral arteries were exposed, 0.6 cm (SD: 0.2) and 0.7 cm (SD: 0.3), respectively. The length of the basilar artery exposed was 2.6 cm (SD: 0.3). The distance from the nasal vestibule to the posterior cerebral artery, superior cerebellar artery, and basilar apex was 10 cm with an SD of ± 0.7, 0.6, and 0.8 cm, respectively. We were able to apply clips on each of these three vessels with a minimal alteration of surrounding normal tissue. The endoscopic endonasal transclival approach represents a potentially feasible surgical corridor to treat aneurysms arising from these vessels.

Petroclival tumor model--technical note and educational implications.

Petroclival area lesions are rare, and their surgery is challenging due to the deep location and to the complex relationships between the tumor and the neurovascular structures. The objective is to present a petroclival tumor model simulating the distorted anatomy of a real petroclival lesion and propose its use to practice microsurgical removal while preserving neurovascular structures. Four embalmed cadaver heads were used in this study. An endoscopic endonasal transclival approach was used to access the dura in front of the trigeminal nerve; a pediatric Foley was inserted above the trigeminal nerve and was gradually inflated (one-balloon technique). If a larger tumor model was desired, an additional balloon was placed below the trigeminal nerve (two-balloon technique). A pre-mixed tumor polymer was injected into the petroclival space and allowed to harden to create an implanted tumor. A post-implant CT scan was done to evaluate the location and volume of the implanted artificial tumor. Tumors were subsequently excised via retrosigmoid and anterior petrosal approaches. Six petroclival tumors were successfully developed: three were small (9.41-10.36 ml) and three large (21.05-23.99 ml). During dissection, distorted anatomy created by the tumor model mimicked that of real surgery. We have established a petroclival tumor model with adjustable size which offers opportunities to study the distorted anatomy of the area and that is able to be used as a training tool to practice microsurgical removal of petroclival lesions. The practice dissection of this tumor model can be a bridge between a normal anatomic dissection and real surgery.

Using the Endoscopic Endonasal Transclival Approach to Access Aneurysms Arising from AICA, PICA, and Vertebral Artery: An Anatomical Study.

Objective To explore the use of the endoscopic endonasal transclival approach (EEA) for clipping anterior inferior cerebellar artery (AICA), posterior inferior cerebellar artery (PICA), and vertebral artery (VA) aneurysms. Design Anatomical study. Participants Fifteen adult cadavers. Main Outcome Measures Length of artery exposed and distance from the nasal ala to the arteries. Results The length of the right and left VA exposed were 1.7 ± 0.6 cm and 1.6 ± 0.6 cm, respectively. The distance to the right VA was 11.1 ± 0.9 cm and to the left was 11.1 ± 0.8 cm. Right and left AICA were exposed for an average length of 1.1 ± 0.3 cm and 0.8 ± 0.3 cm, respectively. The distance to the right AICA was 10.3 ± 0.8 cm and to the left was 10.3 ± 0.8 cm. The right PICA was exposed for a length of 0.5 ± 0.2 cm at a distance of 10.9 ± 0.5 cm. The left PICA was exposed for a length of 0.5 ± 0.2 cm at a distance of 11.1 ± 0.9 cm. Conclusion The EEA can provide direct access to AICA, PICA, and VA, making it a potential alternative to the traditional approaches for the clipping of aneurysms arising from those arteries.

Endoscopic Endonasal Transclival Resection of a Brainstem Cavernoma: A Detailed Account of Our Technique and Comparison with the Literature

To report a technique of endoscopic transclival resection of a hemorrhagic brainstem cavernous malformation manifesting in the ventral pons. A 29-year-old woman presented with numbness and tingling of the right arm and leg and loss of fine motor control. Magnetic resonance imaging revealed a cavernoma in the ventromedial brainstem on the ventral surface. A purely endoscopic, endonasal, transclival approach was used to resect this cavernoma. Computed tomography/magnetic resonance imaging merged navigation (StealthStation, Medtronic) was used. The patient had no neurologic deficits postoperatively. The motor control loss and tingling disappeared. She did not experience any complications. Cerebrospinal fluid leakage appeared to result from using the very small opening of the skull base and dura mater and was the reason for the use of a lumbar drain for several days. At the 6-week follow-up examination, the patient was in excellent condition with no neurologic deficits and had returned to her full-time job. Successful endoscopic, endonasal, transclival resection of a brainstem cavernous malformation was described. This patient experienced improvement in neurologic symptoms after surgery without morbidity. Technologic advances in endoscopic skull base approaches provide access to lesions of the brainstem that previously required more invasive approaches. The endonasal transclival approach provides the most direct route to ventral pontine lesions. Early intervention in brainstem cavernous malformation is indicated and should be performed with an individualized approach taking into consideration the possible complications.

Endoscopic endonasal transclival transodontoid approach for ventral decompression of the craniovertebral junction: operative technique and nuances.

The transoral approach is considered the gold-standard surgical route for performing anterior odontoidectomy and ventral decompression of the craniovertebral junction for pathological conditions that result in symptomatic cervicomedullary compression, including basilar invagination, rheumatoid pannus, platybasia with retroflexed odontoid processes, and neoplasms. Extended modifications to increase the operative corridor and exposure include the transmaxillary, extended "open-door" maxillotomy, transpalatal, and transmandibular approaches. With the advent of extended endoscopic endonasal skull base techniques, there has been increased interest in the last decade in the endoscopic endonasal transclival transodontoid approach to the craniovertebral junction. The endonasal route represents an attractive minimally invasive surgical alternative, especially in cases of irreducible basilar invagination in which the pathology is situated well above the palatine line. Angled endoscopes and instrumentation can also be used for lower-lying pathology. By avoiding the oral cavity and subsequently using a transoral retractor, the endonasal route has the advantages of avoiding complications related to tongue swelling, tracheal swelling, prolonged intubation, velopharyngeal insufficiency, dysphagia, and dysphonia. Postoperative recovery is quicker, and hospital stays are shorter. In this report, the authors describe and illustrate their method of purely endoscopic endonasal transclival odonotoidectomy for anterior decompression of the craniovertebral junction and describe various operative pearls and nuances of the technique for avoiding complications.

Using the Endoscopic Endonasal Transclival Approach to Access AICA, PICA, and Vertebral Artery: A New Surgical Approach for Clipping these Intracranial Aneurysms

Using the Endoscopic Endonasal Transclival Approach to Access AICA, PICA, and Vertebral Artery: A New Surgical Approach for Clipping these Intracranial Aneurysms