Transclival Approach Research Articles

Reconstructive challenges in the extended endoscopic transclival approach.

We wanted to present our experience with the extended endoscopic approach to clival pathology, focusing on cerebrospinal fluid leak and reconstruction challenges. We examined a consecutive series of 37 patients undergoing the extended endoscopic approach for skull base tumours, 9 patients with clival pathology. Patients were examined for the incidence of post-operative cerebrospinal fluid leak in relation to tumour pathology, location, size, reconstruction and lumbar drain. The overall incidence of post-operative cerebrospinal fluid leak was 10.8 per cent. Seventy-five per cent of patients who had a post-operative cerebrospinal fluid leak underwent a transclival approach (p < 0.05). All patients with clival pathology who underwent an intradural dissection had a post-operative cerebrospinal fluid leak (p < 0.05). Post-operative cerebrospinal fluid leak rates after the extended endoscopic approach have improved significantly after advancements including the vascularised nasoseptal flap. Despite this, transclival approaches continue to pose much difficulty. Further investigation is necessary to develop technical improvements that can meet the unique challenges associated with this region.

Use of the pedicled nasoseptal flap in the endoscopic management of cholesterol granulomas of the petrous apex.

Nowadays the endoscopic approach represents a useful alternative to traditional surgical approaches in the treatment of cholesterol granulomas (CGs) of the petrous apex (PA). Recently the nasoseptal flap (NSF) has been employed to permit long-term patency of drainage site. The purpose of this study is to report our experience with the NSF in the endoscopic management of CG and to analyze the advantages, limitations, and outcomes of the technique. A retrospective analysis was carried out on 10 patients affected by CG of the PA who had been treated endoscopically, using the NSF. An endoscopic transpterygoid approach was used for 6 patients and the remaining 4 were treated using the transclival approach. A NSF was used in all 10 cases. In 6 cases the flap was ipsilateral to the lesion whereas in 4 it was contralateral. In 90% of our patients no evidence of disease was observed after a mean follow-up period of 35.7 months, with resolution of their symptoms. One patient presented a recurrence because of a technical error (inadequate placement of the flap in the cavity), and has been retreated endoscopically. The pedicled NSF seems to be helpful in avoiding the concentric growth of the granulomatous cyst epithelium while assuring ventilation and drainage of the cyst. However, bigger studies with longer-term follow-up are needed to confirm these findings. Correct and meticulous placement of the flap inside the cystic cavity is the most critical issue for the success of the procedure.

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

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

Objective: Since the inception of endoscopic skull base surgery, it has continued to evolve through the advent of new technology and surgical corridors. Currently, the expanded endoscopic endonasal approach has given us access to areas of the skull base previously thought not to be approachable through an endonasal technique. Basilar apex aneurysms are the most commonly reported aneurysms in the posterior arterial circulation and have been associated with a higher risk of bleeding, mortality, and morbidity than seen in other locations. In addition, superior cerebellar and posterior cerebral artery aneurysms are seen less frequently, but they can be associated with basilar apex aneurysms. Different surgical approaches and endovascular interventions have been described for the management of these aneurysms, but they can sometimes be associated with high clinical morbidity. The goal of this is study was to explore the feasibility of an endoscopic endonasal transclival approach to treat aneurysms arising in these vessels.

Endoscopic Endonasal Transclival Approach to the Petroclival Meningioma

Objective: The current management paradigm for petroclival meningioma includes surgical approaches utilized extensive bone drilling, brain retraction, and cranial nerve manipulation. We have experienced a new approach such as the endoscopic endonasal transclival approach to the petroclival meningioma. Patients/material and Methods: We used the endoscopic endonasal approach in a patient who was a 53-year-old lady suffered from the petroclival meningioma incidentally found. The patient underwent the embolization of the tumor feeding vessels from biexternal carotid arteries to reduce the bleeding using ethanol substance and the next day, we tried to remove the tumor directly to the basement of the tumor along the transnasal corridor without brain retraction. During operation we used bilateral nasal pedicle flaps to prevent the CSF leakage and the navigation system for the detection to the correct position of the manipulation to the tumor. Results: The tumor was subtotally removed without massive bleeding and no CSF leakage occurred. The patient has had no neurological deficits at the postoperative state. Conclusions: The endoscopic endonasal transclival approach to the petroclival meningioma could be found sort of innovative because of a less invasive and more direct approach than a traditional transcranial approach from this case. This approach to the petroclival meningioma would represent more sophisticated and widespread approach in the future.

Endoscopic endonasal transclival approaches: case series and outcomes for different clival regions.

Objective Transclival endoscopic endonasal approaches to the skull base are novel with few published cases. We report our institution's experience with this technique and discuss outcomes according to the clival region involved. Design Retrospective case series. Setting Tertiary care academic medical center Participants All patients who underwent endoscopic endonasal transclival approaches for skull base lesions from 2008 to 2012. Main Outcome Measures Pathologies encountered, mean intraoperative time, intraoperative complications, gross total resection, intraoperative cerebrospinal fluid (CSF) leak, postoperative CSF leak, postoperative complications, and postoperative clinical course. Results A total of 49 patients underwent 55 endoscopic endonasal transclival approaches. Pathology included 43 benign and 12 malignant lesions. Mean follow-up was 15.4 months. Mean operative time was 167.9 minutes, with one patient experiencing an intraoperative internal carotid artery injury. Of the 15 cases with intraoperative cerebrospinal fluid (CSF) leaks, 1 developed postoperative CSF leak (6.7%). There were six other postoperative complications: four systemic complications, one case of meningitis, and one retropharyngeal abscess. Gross total resection was achieved for all malignancies approached with curative intent. Conclusions This study provides evidence that endoscopic endonasal transclival approaches are a safe and effective strategy for the surgical management of a variety of benign and malignant lesions. Level of Evidence 4.

Full endoscopic endonasal transclival approach: Meningioma attached to the ventral surface of the brainstem

Intracranial meningiomas without dural attachment (MWODA) are rare entities. We present the first case published, to the best of our knowledge, regarding a MWODA attached to the ventral surface of the brainstem. This location makes the patient subsidiary to treatment through an expanded endonasal transclival approach. A 16-year-old female with suspected diagnosis of recurrence of a clear cell meningioma (CCM) at a distance from the initial lesion, located on the premedullary cistern. The patient underwent a pure endoscopic low transclival approach. The attachment to the ventral surface of the brainstem was confirmed intraoperatively. Postoperative MRI confirmed gross total resection and treatment was complemented with adjuvant fractionated stereotactic radiotherapy. No complications related to the procedure were observed. MWODA may appear attached to the ventral brainstem. The expanded endonasal approach to the clivus provides a critical anatomical advantage in the treatment of medial lesions, even ventral meningiomas, to the lower cranial nerves. Reconstruction principles must be strictly respected to reduce complications.

Endoscopic Resection of a Giant Intradural Retroclival Ecchordosis Physaliphora

Objective: We report the first complete resection of a giant ecchordosis physaliphora (EP) using an endoscopic transclival approach. We describe the surgical technique employed and provide a current review of the literature.

Extended endoscopic endonasal transclival approach to the ventrolateral brainstem and related cisternal spaces: anatomical study

Advances in endoscopic endonasal skull base surgery have led to the development of new routes to areas beyond the midline skull base. Recently, feasible surgical corridors to the lateral skull base have been described. The aim of this study was to describe the anatomical exposure of the ventrolateral brainstem and posterior fossa through an extended endoscopic endonasal transclival transpetrosal and transcondylar approach. Six human heads were used for the dissection process. The arterial and venous systems were injected with red- and blue-colored latex, respectively. A pre- and postoperative computed tomography (CT) scan was carried out on every head. The endoscopic endonasal transclival approach was extended through an anterior petrosectomy and a medial condylectomy. A three-dimensional model of the approach was reconstructed, using a dedicated software, from the overlapping of the pre- and post-dissection CT imaging of the specimen. An extended endoscopic transclival approach allows to gain access through an extradural anterior petrosectomy and medial condylectomy to the anterolateral surface of the brainstem and the posterior fossa. Two main intradural anatomical corridors can be described: first, between the V cranial nerve in the prepontine cistern and the VII-VIII cranial nerves in the cerebellopontine and cerebellomedullary cistern; second, between the VII-VIII cranial nerves and the IX cranial nerve, in the premedullary cistern. Extending the transclival endoscopic approach by performing an extradural anterior petrosectomy and a medial condylectomy provides a safe and wide exposure of the anterolateral brainstem with feasible surgical corridors around the main neurovascular structures.

A Case of Endoscopic Removal of Clival Chordoma through Extended Transclival Approach

사대 척삭종(clival chordoma)은 두개저의 사대(clivus)에 발생하는 종양으로, 태아기 척삭조직(fetal notochordal tissue) 의 잔존조직으로부터 유래한 두개저종양(skull base tumor) 으로서 원발성 두개내 종양의 0.2%에 지나지 않는 희귀한 종양 이다. 저등도에서 중등도의 위험성을 가지는 임상적 악성 종 양으로 분류되며, 원격전이는 드물지만, 국소적으로 침습적인 습성을 가졌고, 흔히 재발하는 습성을 지녀 예후가 좋지 않은 것으로 알려져 있다. 주위 조직을 침습하고 재발을 잘 하는 특 성과 발생위치 때문에 수술적 접근 및 완전제거가 어려운 종 양에 속한다. 주로 신경외과에서 다양한 접근법을 통해 수 술해 왔으나, 최근에는 내시경 기술의 발달로 내시경적 접근을 통해 수술하는 경우가 늘어나고 있으며, 합병증은 줄이고 수 술시간도 단축되며 육안적 완전제거 달성률이 높은 등 우수한 결과를 보이는 수술법으로서 보고되고 있다. 본원에서는 경비중격 접근을 통해 이미 한 번 수술 받았으나 재발하여 내원한 사대 척삭종 환자에 대해 비내시경을 이용 한 경사대 접근법을 통해 성공적으로 제거한 1예가 있어 이를 보고하고자 한다.

Focal Transnasal Approach to the Upper, Middle, and Lower Clivus

Carefully tailoring the transclival approach to the involved parts of the upper, middle, or lower clivus requires a precise understanding of the focal relationships of the clivus. To develop an optimal classification of the upper, middle, and lower clivus and to define the extra and intracranial relationships of each clival level. Ten cadaveric heads and 10 dry skulls were dissected using the surgical microscope and endoscope. The clivus is divided into upper, middle, and lower thirds by 2 endocranial landmarks: the dural pori of the abducens nerves and the dural meati of the glossopharyngeal nerves. Useful surgical landmarks exposed in the transnasal approach that aid in locating the junction of the clival divisions are the lower limit of the paraclival segment of the internal carotid artery, which is located 4.9 mm above the posterior opening of the vidian canal, and the pharyngeal tubercle. The upper, middle, and lower clival approaches provide access to the anterior midline parts of the previously described upper, middle, and lower neurovascular complexes in the posterior fossa. The nasal and nasopharyngeal relationships important in expanding the transnasal approach to the borders of the clivus are reviewed. The transclival approach can be carefully tailored to expose focal lesions in the anterior part of the posterior fossa.

Practice patterns in endoscopic skull base surgery: survey of the American Rhinologic Society

The introduction of advanced endoscopic techniques has facilitated significant growth in the field of endoscopic skull base surgery (SBS). The purpose of this study is to evaluate the impact of endoscopic SBS on the clinical practice patterns of the American Rhinologic Society (ARS) membership. A 23-item survey vetted by the ARS Board of Directors was electronically disseminated to the ARS membership from February 5, 2013, to March 31, 2013. The target group encompassed 982 ARS members. A total of 152 physicians (15.5%) completed the survey. Open and endoscopic skull base procedures were performed by 41% and 94% of the respondents, respectively. During a typical year, the number of endoscopic skull base cases ranged from 0 to 20 in 56%, 21 to 50 in 26%, 51 to 100 in 9%, and >100 in 8%. Endoscopic cerebrospinal fluid (CSF) leak repair (96%) and transsphenoidal pituitary surgery (81%) were the most commonly performed procedures, followed by transcribriform (68.4%), transplanum (54.4%), and transclival (49.6%) approaches. Overall, 69.6% used endoscopy for resections of malignant sinus/skull base lesions. Considerable variation in Current Procedural Terminology (CPT) coding philosophy was observed, with open skull base (32%), unlisted endoscopic (29%), sinus surgery (24%), and unlisted neurosurgical (15%) codes employed by surgeons. Only 29% of physicians reported adequate reimbursement in ≥75% of cases. Eighty-five percent of respondents supported creation of dedicated endoscopic SBS codes. This study illustrates the widespread integration of endoscopic SBS procedures into rhinologic clinical practice among survey respondents. However, current variability in coding strategies and inadequate reimbursement may warrant development of specific guidelines to standardize coding and billing processes in the future.

Anatomical and computed tomographic analysis of the transcochlear and endoscopic transclival approaches to the petroclival region

Advances in the field of skull base surgery aim to maximize anatomical exposure while minimizing patient morbidity. The petroclival region of the skull base presents numerous challenges for surgical access due to the complex anatomy. The transcochlear approach to the region provides adequate access; however, the resection involved sacrifices hearing and results in at least a grade 3 facial palsy. An endoscopic endonasal approach could potentially avoid negative patient outcomes while providing a desirable surgical window in a select patient population. Cadaveric study. Endoscopic access to the petroclival region was achieved through an endonasal approach. For comparison, a transcochlear approach to the clivus was performed. Different facets of the dissections, such as bone removal volume and exposed surface area, were computed using computed tomography analysis. The endoscopic endonasal approach provided a sufficient corridor to the petroclival region with significantly less bone removal and nearly equivalent exposure of the surgical target, thus facilitating the identification of the relevant anatomy. The lateral approach allowed for better exposure from a posterolateral direction until the inferior petrosal sinus; however, the endonasal approach avoided labyrinthine/cochlear destruction and facial nerve manipulation while providing an anteromedial viewpoint. The endonasal approach also avoided external incisions and cosmetic deficits. The endonasal approach required significant sinonasal resection. Endoscopic access to the petroclival region is a feasible approach. It potentially avoids hearing loss, facial nerve manipulation, and cosmetic damage.

Augmented real‐time navigation with critical structure proximity alerts for endoscopic skull base surgery

Image-guided surgery (IGS) systems are frequently utilized during cranial base surgery to aid in orientation and facilitate targeted surgery. We wished to assess the performance of our recently developed localized intraoperative virtual endoscopy (LIVE)-IGS prototype in a preclinical setting prior to deployment in the operating room. This system combines real-time ablative instrument tracking, critical structure proximity alerts, three-dimensional virtual endoscopic views, and intraoperative cone-beam computed tomographic image updates. Randomized-controlled trial plus qualitative analysis. Skull base procedures were performed on 14 cadaver specimens by seven fellowship-trained skull base surgeons. Each subject performed two endoscopic transclival approaches; one with LIVE-IGS and one using a conventional IGS system in random order. National Aeronautics and Space Administration Task Load Index (NASA-TLX) scores were documented for each dissection, and a semistructured interview was recorded for qualitative assessment. The NASA-TLX scores for mental demand, effort, and frustration were significantly reduced with the LIVE-IGS system in comparison to conventional navigation (P < .05). The system interface was judged to be intuitive and most useful when there was a combination of high spatial demand, reduced or absent surface landmarks, and proximity to critical structures. The development of auditory icons for proximity alerts during the trial better informed the surgeon while limiting distraction. The LIVE-IGS system provided accurate, intuitive, and dynamic feedback to the operating surgeon. Further refinements to proximity alerts and visualization settings will enhance orientation while limiting distraction. The system is currently being deployed in a prospective clinical trial in skull base surgery.

Improving the endoscopic endonasal transclival approach: the importance of a precise layer by layer reconstruction

Background. The endoscopic endonasal transclival approach (EETCA) is a minimally-invasive technique allowing a direct route to the base of implant of clival lesions with reduced brain and neurovascular manipulation. On the other hand, it is associated with potentially severe complications related to the difficulties in reconstructing large skull base defects with a high risk of postoperative cerebrospinal fluid (CSF) leakage. The aim of this paper is to describe a precise layer by layer reconstruction in the EETCA including the suture of the mucosa as an additional reinforcing layer between cranial and nasal cavity in order to speed up the healing process and reduce the incidence of CSF leak. Methods. This closure technique was applied to the last six cases of EETCA used for clival meningiomas (2), clival chordomas (2), clival metastasis (1), and craniopharyngioma with clival extension (1). Results. After a mean follow-up of 6 months we had no one case of postoperative CSF leakage or infections. Seriated outpatient endoscopic endonasal controls showed a fast healing process of nasopharyngeal mucosa with less patient discomfort. Conclusions. Our preliminary experience confirms the importance of a precise reconstruction of all anatomical layers violated during the surgical approach, including the nasopharygeal mucosa.

Endoscopic endonasal transclival approach to a ventral pontine pediatric ependymoma

The authors report a case of a recurrent pediatric ventral pontine ependymoma that they resected through an endonasal endoscopic transclival approach. Regarding the options for a surgical approach to ventral pontine tumors, traditional far-lateral approaches are associated with considerable morbidity due to the required muscle mobilization, brain retraction, and in-line obstruction of cranial nerves before reaching the target. The endoscopic endonasal transclival approach was made appealing by eliminating all of these concerns. The patient's fully pneumatized sphenoid sinus, laterally displaced basilar artery, and the direct ventral location of the bulky disease all further supported this unconventional choice of surgical corridor to achieve a palliative brainstem decompression of an incurable recurrence.

Endoscopic Skull Base Surgery Practice Patterns: Survey of the North American Skull Base Society

Background The objective of this study was to evaluate the potential impact of advanced endoscopic techniques on the current practice patterns in skull base surgery. Methods A 20-item written survey approved by the American Rhinologic Society (ARS) and North American Skull Base Society (NASBS) was conducted at the 22nd Annual NASBS meeting in Las Vegas, NV, from February 17 to 19, 2012. The target group included 212 practicing skull base surgeons. Results Seventy-nine physicians (37.3%) completed the survey. The subspecialty composition was 42 (53%) otolaryngologists and 35 (44%) neurosurgeons. The respondents represented all regions of the country, with most common being the North Central (24%) and Mid-Atlantic (23%) states. Open and endoscopic skull base techniques were used by 91% and 80%, respectively. During a typical year, the number of endoscopic skull base cases ranged between 20 and 50 in 32%, 50 to 100 in 13%, and >100 in 8%. Endoscopic pituitary surgery was performed by 95%, while transcribriform, transplanum, and transclival approaches were performed by 70.5%, 66%, and 66%, respectively. Wide variation in coding philosophy was noted, including use of unlisted neurosurgical (28%), open skull base (28%), unlisted endoscopic (24%), and sinus surgery (20%) codes. Only 30% of physicians reported adequate reimbursement in ≥50% of the performed cases. Overall, 87% were supportive of the creation of dedicated endoscopic skull base codes. Conclusion The present survey attests to the widespread adaptation of endoscopic techniques in the management schema of skull base surgery. The wide variation in coding techniques and inadequate reimbursement suggests that future dialogue should also focus on developing consensus with respect to the coding and billing process.

Endoscopic skull base surgery practice patterns: survey of the North American Skull Base Society

The objective of this study was to evaluate the potential impact of advanced endoscopic techniques on the current practice patterns in skull base surgery. A 20-item written survey approved by the American Rhinologic Society (ARS) and North American Skull Base Society (NASBS) was conducted at the 22nd Annual NASBS meeting in Las Vegas, NV, from February 17 to 19, 2012. The target group included 212 practicing skull base surgeons. Seventy-nine physicians (37.3%) completed the survey. The subspecialty composition was 42 (53%) otolaryngologists and 35 (44%) neurosurgeons. The respondents represented all regions of the country, with most common being the North Central (24%) and Mid-Atlantic (23%) states. Open and endoscopic skull base techniques were used by 91% and 80%, respectively. During a typical year, the number of endoscopic skull base cases ranged between 20 and 50 in 32%, 50 to 100 in 13%, and >100 in 8%. Endoscopic pituitary surgery was performed by 95%, while transcribriform, transplanum, and transclival approaches were performed by 70.5%, 66%, and 66%, respectively. Wide variation in coding philosophy was noted, including use of unlisted neurosurgical (28%), open skull base (28%), unlisted endoscopic (24%), and sinus surgery (20%) codes. Only 30% of physicians reported adequate reimbursement in ≥50% of the performed cases. Overall, 87% were supportive of the creation of dedicated endoscopic skull base codes. The present survey attests to the widespread adaptation of endoscopic techniques in the management schema of skull base surgery. The wide variation in coding techniques and inadequate reimbursement suggests that future dialogue should also focus on developing consensus with respect to the coding and billing process.

A cadaveric study of the endoscopic endonasal transclival approach to the basilar artery

The anterior transclival route to basilar artery aneurysms is not widely performed. The objective of this study was to carry out a feasibility assessment of the transclival approach to basilar aneurysms with advanced endonasal techniques on 11 cadaver heads. Clival dura was exposed from the sella to the foramen magnum between the paraclival segments of the internal carotid arteries (ICA) laterally. An inverted dural “U” flap was reflected inferiorly to expose the basilar artery. The maximal dimensions from operative measurements were recorded. Surgical manoeuvrability of multiple instruments and the proficiency to place proximal and distal vascular clips were evaluated. The mean operative depth (± standard deviation), measured from the anterior choanae to the basilar artery, was 110±6mm. The lateral corridors were limited distally by the medial pterygoids (mean width 21±2mm) and paraclival ICA (mean width 20±2mm). The mean transclival craniectomy dimensions were 19±2mm (width) and 23±4mm (height). Exposure of the basilar–anterior inferior cerebellar artery junction, superior cerebellar artery, and the basilar caput were possible in 100%, 91%, and 64% of instances, respectively. Placements of proximal and distal aneurysm clips were achieved in all instances. Based on our findings, the transclival endoscopic endonasal surgery approach provides excellent visualisation of the basilar artery. Clip application and manoeuvrability of instruments was considered adequate for basilar aneurysm surgery. Surgical skills and instrumentation to control significant haemorrhage can potentially limit the clinical applicability of this technique.

Anatomical restrictions in the transsphenoidal, transclival approach to the upper clival region: A cadaveric, anatomic study

ObjectiveTumours in the clival region are difficult to remove surgically. Before the 1970s, clival tumours had very high mortality and morbidity rates. MethodsAn anatomic dissection was performed on 24 spheno-occipital bone blocks obtained from 28 adult cadavers. The internal carotid artery, paraclival carotid tubercle, sixth cranial nerve and dorsum sellae in the upper clival region were analyzed qualitatively and quantitatively. For the histological evaluation, 4 samples were decalcified and sagittal sections were cut. From the eight blocks obtained, 32 incisions were made in the axial plane, and the tissue was analyzed. ResultsUsing microscopy, a clival recess was clearly identified in 15 of the 24 (62.5%) samples. Paraclival carotid tubercles were observed in 19 (79.16%) of the samples. In the upper clival and petroclival region, the sixth cranial nerve had directional changes at the dural porus, the petrous apex and the lateral wall of the cavernous segment of the internal carotid artery. At the dorsum sellae level, the distance between the medial surfaces of both internal carotid arteries was a mean of 15.33 ± 2.12 mm. This distance at the pharyngeal tubercle was a mean of 38.95 ± 4.67 mm. On all the histological sections, the distance of the sixth cranial nerve from the dural porus to the cavernous sinus was within the basilar plexus, along with the subarachnoid membranes around it. On the petrous apex level, the sixth cranial nerve was fixed to the petrous apex and the internal carotid artery with connective tissue formed by dense collagen fibres. The sixth cranial nerve and the internal carotid artery are tightly surrounded by dense collagen connective tissue, and the relative proximity between the carotids on the dorsum sellae level can be easily damaged during the transsphenoidal–transclival approach. Similarly, due to the ligamentous fixation on the dural porus and the petrous apex surfaces, there is a high risk of injury to the carotid artery and sixth cranial nerve. ConclusionThis study determines the relationship between the sixth cranial nerve and the internal carotid artery at the upper clivus and to provide morphologic details that is essential for the risks of transclival surgery.