Expanded endonasal approach: a fully endoscopic completely transnasal resection of a skull base arteriovenous malformation

Nasal Surgery in the Younger Patient

Nasal surgery can be carried out safely in the younger patient. In cases of trauma, it is recommended that corrective surgery be carried out in a short time frame before scar contracture, aberrant remodeling, and malunion of structures occurs. In the less common situation of performing cosmetic surgery on the younger patient there are several principles and guidelines to be considered.

Craniopharyngioma resection and aneurysm clipping performed simultaneously by pure endoscopic endonasal approach: A case report and literature review

Craniopharyngioma is one of the most challenging issues for neurosurgeons as a brain tumor. Among the approaches of neurosurgery, in comparison to craniotomy, the endoscopic endonasal approach (EEA) has risen in popularity over the last two decades; unruptured intracranial aneurysms are relatively commonly found in the general population. The EEA as a new paradigm in the treatment of aneurysm has been reported to successfully clip dozens of cases of intracranial aneurysm. However, when reviewing the domestic and foreign literature, it appeared that cases of craniopharyngioma complicated with intracranial aneurysm purely treated by EEA have not been reported so far. In the present study, the published literature regarding endoscopic endonasal surgery for craniopharyngioma and intracranial aneurysms was reviewed, accompanied with a case of craniopharyngioma complicated with intracranial aneurysm, both of which were simultaneously treated by EEA.

Two rare cases of sinonasal vascular malformation in the pediatric population

Vascular malformations presenting in the nasal cavity and paranasal sinuses are rare. Differentiating benign vascular malformations of the sinonasal cavity from other pathologic entities can be challenging and the role of preoperative angiography and embolization is not well defined. We present two unique cases of large pediatric sinonasal vascular malformations and describe their presentation, diagnosis and subsequent management. Both patients underwent embolization of the ipsilateral arterial supply followed by successful and complete endonasal surgical excision. This report provides description of management of the very rare occurrence of sinonasal vascular malformation in two adolescents.

Extended Endoscopic Endonasal Clipping of Intracranial Aneurysms: An Anatomic Feasibility Study

BACKGROUND

Intracranial aneurysms (IAs) located in the midline region represent formidable challenge owing to their deep location. The objective of this study was to assess feasibility and identify the limitations of endoscopic endonasal clipping of IAs. We further aimed to describe the locations and characteristics of aneurysms that may be amenable for endoscopic endonasal clipping; thus outlining the indications of these approaches.

METHODS

Fifteen latex-injected cadaveric heads were used for endoscopic endonasal exposure of anterior and posterior cerebral circulations. An aneurysm simulator model with 2 different sizes was used at the common sites for IAs to emulate a real surgery. Key measured parameters included "exposure of vessels and their respective perforators," "ability to gain proximal/distal control," and "possibility of clip placement" according to the size, direction, and location of the aneurysm model. Maneuverability of instruments and the need for pituitary gland transposition were assessed and recorded as well.

RESULTS

Exposure of the anterior communicating artery complex and the common sites of posterior circulation aneurysms were feasible. The size, location, and direction of the aneurysm model had an impact on obtaining proximal and/or distal control, and the ability of clip placement.

CONCLUSIONS

Clipping of midline aneurysms of the posterior circulation is feasible via endoscopic endonasal approach. Small-sized ventrally and medially directed aneurysm models carried a better probability of getting proximal and/or distal control, as well as better overall ability to place a clip. The endonasal route seems to provide a limited condition for proper management of anterior circulation aneurysms.

Transnasal endoscopic approach for pediatric skull base lesions: a case series

OBJECTIVE

Transnasal endoscopic transsphenoidal approaches constitute an essential technique for the resection of skull base tumors in adults. However, in the pediatric population, sellar and suprasellar lesions have historically been treated by craniotomy. Transnasal endoscopic approaches are less invasive and thus may be preferable to craniotomy, especially in children. In this case series, the authors present their institutional experience with transnasal endoscopic transsphenoidal approaches for pediatric skull base tumors.

METHODS

The authors retrospectively reviewed pediatric patients (age ≤ 18 years) who had undergone transnasal endoscopic transsphenoidal approaches for either biopsy or resection of sellar or suprasellar lesions between 2007 and 2016. All operations were performed jointly by a team of pediatric neurosurgeons and skull base otolaryngologists, except for 8 cases performed by one neurosurgeon.

RESULTS

The series included 42 patients between 4 and 18 years old (average 12.5 years) who underwent 51 operations. Headache (45%), visual symptoms (69%), and symptoms related to hormonal abnormalities (71%) were the predominant presenting symptoms. Improvement in preoperative symptoms was seen in 92% of cases. Most patients had craniopharyngiomas (n = 16), followed by pituitary adenomas (n = 12), Rathke cleft cysts (n = 4), germinomas (n = 4), chordomas (n = 2), and other lesion subtypes (n = 4). Lesions ranged from 0.3 to 6.2 cm (median 2.5 cm) in their greatest dimension. Gross-total resection was primarily performed (63% of cases), with 5 subsequent recurrences. Nasoseptal flaps were used in 47% of cases, fat grafts in 37%, and lumbar drains in 47%. CSF space was entered intraoperatively in 15 cases, and postoperative CSF was observed only in lesions with suprasellar extension. There were 8 cases of new hormonal deficits and 3 cases of new cranial nerve deficits. Length of hospital stay ranged from 1 to 61 days (median 5 days). Patients were clinically followed up for a median of 46 months (range 1-120 months), accompanied by a median radiological follow-up period of 45 months (range 3.8-120 months). Most patients (76%) were offered adjuvant therapy.

CONCLUSIONS

In this single-institution report of the transnasal endoscopic transsphenoidal approach, the authors demonstrated that this technique is generally safe and effective for different types of pediatric skull base lesions. Favorable effects of surgery were sustained during a follow-up period of 4 years. Further refinement in technology will allow for more widespread use in the pediatric population.

The application of nasoseptal "rescue" flap technique in endoscopic transsphenoidal pituitary adenoma resection

To explore the reliability and superiority of nasoseptal "rescue" flap technique in neuroendoscopic transnasal pituitary adenoma resection. Retrospective clinical analysis of 113 cases of endoscopic transsphenoid pituitary adenoma resection with the application of nasoseptal "rescue" flap technology. The reliability and the superiority of the technique were evaluated according to the duration of nasal cavity and sphenoid sinus stage, the incidence of postoperative anosmia, and cerebrospinal rhinorrhea. The duration of nasal and sphenoid sinus stage was 15-30 min, averaging 24 min. There were 27 cases of intro-operative cerebrospinal fluid leakage, including 24 cases of low-flow cerebrospinal fluid leak and 3 cases of high-flow cerebrospinal fluid leak. Twenty-three cases were converted from nasoseptal "rescue" flap to nasal septum flap. There were 17 cases of postoperative olfactory decline or disappearance, 1 case of epistaxis and 1 case of cerebrospinal rhinorrhea. The application of nasoseptal "rescue" flap technique can proceed sellar floor reconstruction when the diaphragma sellae rupture occurs during the operation. There is no obvious increase of the duration of sphenoid sinus and nasal stage and the rate of postoperative olfactory loss. This technique can be used as a conventional technique for endoscopic transsphenoid pituitary adenoma resection.

Endoscopic Endonasal Clipping of Anterior Circulation Aneurysm: Surgical Techniques and Results

BACKGROUND

Endoscopic endonasal clipping of intracranial aneurysms may use microsurgical techniques as an alternative to the transcranial approach. Here we report a series of patients who underwent microsurgical clipping of anterior circulation aneurysms via an endoscopic endonasal approach (EEA).

METHODS

This retrospective chart review included all the patients who underwent standard binostril EEA for aneurysm clipping. Surgical outcomes and complications are noted. The rationality and limitations of this procedure are discussed.

RESULTS

Seven patients with 12 aneurysms of the anterior circulation underwent EEA for clipping. These 12 aneurysms consisted of 5 anterior communicating artery (AComA) aneurysms, 4 paraclinoid aneurysms, 1 ophthalmic artery aneurysm, and 2 aneurysm located in the cavernous segment of internal carotid artery (ICA). Nine of the 12 aneurysms were successfully clipped. One giant paraclinoid aneurysm could not be clipped during operation and was coiled in second endovascular stage. The 2 aneurysms located in the cavernous segment of ICA were not clipped intentionally in a single-stage procedure, after weighing the surgical benefit against the difficulty of surgical exposure and feasibility. The proximal control of ICA was achieved in all cases. There was no death, no cerebrospinal fluid leak, or other complications. All patients recovered completely.

CONCLUSIONS

EEA can provide direct access for microsurgical clipping of strictly selected anterior circulation aneurysms. All the principles of cerebrovascular surgery must be followed. These procedures require a long learning curve. Only teams with adequate experience in microvascular and endoscopic skull base surgeries should attempt this approach for treating aneurysms.

Transfacial and Craniofacial Approaches for Resection of Sinonasal and Ventral Skull Base Malignancies

Malignancies of the paranasal sinuses and ventral skull base present unique challenges to physicians. A transfacial or craniofacial approach allows for wide, possibly en bloc, resection and is ideal for tumors that involve surrounding soft tissue, the palate, the orbit, anterolateral frontal sinus, and lateral dura. Transfacial approaches include a lateral rhinotomy often combined with a medial, subtotal, or total maxillectomy. Reconstruction is most commonly performed with a pericranial flap to separate the intranasal and intracranial compartments. These approaches have evolved and been refined but now are usually reserved for advanced tumors not amenable to endoscopic resection.

Complications of Open Approaches to the Skull Base in the Endoscopic Era

Objective It is important to characterize the developing complication profile of the open approach as it becomes reserved for more complex disease during the endoscopic era. Our objective was to characterize complication rates of current open skull base surgery. Design Retrospective chart review. Setting Tertiary care center. Participants The study group consisted of 103 patients and 117 open skull base surgeries were performed from 2008 to 2012. Main Outcome Measures Intraoperative/postoperative complications. Methods Fisher exact test and Wilcoxon rank sum test evaluated for associations of complications with potential risk factors. Results Postoperative complications occurred in 53 (45%) cases, of which 36 (31%) were major complications. Malignancy, dural grafting, age, and obesity were not associated with complications. Flap reconstruction was associated with increased complication rates (odds ratio = 2.27; 95% confidence interval: 1.03-5.04). Conclusion The open approach is increasingly utilized for only the most complex lesions, and selection bias cannot be overstated in comparative series. This study suggests that current open complication rates may be above those cited from prior studies, and patient and physician expectations should be adjusted accordingly.

Pure Endoscopic Endonasal Clipping of an Incidental Anterior Communicating Artery Aneurysm

Anterior communicating artery (AcoA) aneurysm is the most common form of intracranial aneurysm. It occurs rarely together with other intracranial lesion. Today, microsurgical techniques and endovascular methods are used in the treatment of these aneurysms. Endoscopic endonasal approach is a useful technique for midline lesions of the skull base and is underpinned with extensive experience. In this article, we present a 72-year-old female patient who underwent endoscopic endonasal transplanum-transtubercular surgery for tuberculum sellae meningioma followed by clipping of the incidental AcoA aneurysm. After complete removal of a tuberculum sellae meningioma via an endoscopic endonasal approach, an anterior and superior projected saccular AcoA aneurysm in the gyrus rectus area was totally clipped successfully via pure endoscopic endonasal transplanum-transtubercular approach, without any damage to parent arteries. The patient was discharged from the hospital within a short period of time without any postoperative complication. Endoscopic endonasal approach is a new paradigm in the treatment of aneurysm. Although this technique cannot be routinely used due to lack of experience, it is an effective and safe method in selected and anatomically appropriate cases. We believe that increased knowledge and experience will create successful results in this approach, and it can offer an alternative method for selected aneurysm cases.

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

OBJECTIVE

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.

STUDY DESIGN

Cadaveric anatomical study.

PARTICIPANTS

Fifteen cadaveric specimens.

MAIN OUTCOME MEASURES

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.

RESULTS

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.

CONCLUSION

The endoscopic endonasal transclival approach represents a potentially feasible surgical corridor to treat aneurysms arising from these vessels.

Endoscopic endonasal clip ligation of cerebral aneurysms: an anatomical feasibility study and future directions

OBJECTIVE

The expansion of endovascular procedures for obliteration of cerebral aneurysms highlights one of the drawbacks of clip ligation through the transcranial route, namely brain retraction or brain transgression. Sporadic case reports have emerged over the past 10 years describing endonasal endoscopic clip ligation of cerebral aneurysms. The authors present a detailed anatomical study to evaluate the feasibility of an endoscopic endonasal approach for application of aneurysm clips.

METHODS

Nine human cadaveric head specimens were used to evaluate operative exposures for clip ligation of aneurysms in feasible anterior and posterior circulation locations. Measurements of trajectories were completed using a navigation system to calculate skull base craniectomy size, corridor space, and the surgeon's ability to gain proximal and distal control of parent vessels.

RESULTS

In each of the 9 cadaveric heads, excellent exposure of the target vessels was achieved. The transplanum, transtuberculum, and transcavernous approaches were used to explore the feasibility of anterior circulation access. Application of aneurysm clips was readily possible to the ophthalmic artery, A1 and A2 segments of the anterior cerebral artery, anterior communicating artery complex, and the paraclinoid and paraclival internal carotid artery. The transclival approach was explored, and clips were successfully deployed along the proximal branches of the vertebrobasilar system and basilar trunk and bifurcation. The median sizes of skull base craniectomy necessary for exposure of the anterior communicating artery complex and basilar tip were 3.24 cm(2) and 4.62 cm(2), respectively. The mean angles of surgical corridors to the anterior communicating artery complex and basilar tip were 11.4° and 14°, respectively. Although clip placement was feasible on the basilar artery and its branches, the associated perforating arteries were difficult to visualize, posing unexpected difficulty for safe clip application, with the exception of ventrolateral-pointing aneurysms.

CONCLUSIONS

The authors characterize the feasibility of endonasal endoscopic clip ligation of aneurysms involving the paraclinoid, anterior communicating, and basilar arteries and proximal control of the paraclival internal carotid artery. The endoscopic approach should be initially considered for nonruptured aneurysms involving the paraclinoid and anterior communicating arteries, as well as ventrolateral basilar trunk aneurysms. Clinical experience will be mandatory to determine the applicability of this approach in practice.

Endoscopic Endonasal Clipping of Intracranial Aneurysms: Surgical Technique and Results

OBJECTIVE

Microsurgical clipping of intracranial aneurysms requires meticulous technique and is usually performed through open approaches. Endoscopic endonasal clipping of intracranial aneurysms may use the same techniques through an alternative corridor. The aim of this article is to report a series of patients who underwent an endoscopic endonasal approach (EEA) for microsurgical clipping of intracranial aneurysms.

METHODS

We conducted a retrospective chart review. Surgical outcome and complications were noted. The conceptual application and the technical nuances of these procedures are discussed.

RESULTS

Ten patients underwent EEA for clipping of 11 intracranial aneurysms arising from the paraclinoidal internal carotid artery (n = 9) and vertebrobasilar system (n = 2). The internal carotid artery aneurysms projected medially, whereas the vertebrobasilar artery aneurysms were directly ventral to the brainstem with low-lying basilar apices. One patient required craniotomy for distal control given the size and thrombosed nature of the aneurysm. Proximal and distal vascular control with direct visualization of the aneurysm was obtained in all patients. In all cases, aneurysms were completely occluded. Among complications, 3 patients had postoperative cerebrospinal fluid leakage and 2 other patients had meningitis. Two patients suffered lacunar strokes. One recovered completely and the other remains with mild disabling symptoms.

CONCLUSIONS

EEAs can provide direct access for microsurgical clipping of rare and carefully selected intracranial aneurysms. The basic principles of cerebrovascular surgery have to be followed throughout the procedure. These surgeries require a skull base team with a neurosurgeon well versed in both endoscopic endonasal and cerebrovascular surgery, working in concert with an otolaryngologist experienced in skull base endoscopy and reconstruction.

Corrective nasal surgery in the younger patient

IMPORTANCE To describe clinical parameters for the management of the pediatric patient with nasal anatomical deformity or functional impairment. OBJECTIVES To review the authors' experience with corrective nasal surgery in pediatric patients and make recommendations regarding indications for surgery and surgical techniques. DESIGN, SETTING, AND PARTICIPANTS A retrospective medical chart review was performed for all male patients younger than 16 years and female patients younger than 14 years seen by the senior author (F.G.F.) at a tertiary referral center between August 1996 and August 2012. The database was searched for patients who underwent septoplasty or corrective nasal surgery by the senior author. EXPOSURES Patients included in the study underwent either septoplasty or corrective nasal surgery by the senior author. MAIN OUTCOMES AND MEASURES Age, indication for surgery, surgery performed, and last follow-up appointment was recorded for each patient. In addition, any complications or need for revision surgical or adjunct procedures were noted. RESULTS Demographics and outcomes for 54 pediatric patients were included in the study. The most common indications for surgery were posttraumatic deformities (n = 36) and severe airway obstruction (n = 48). Fifteen patients with severe nasal airway obstruction did not have a documented history of trauma. The mean follow-up period was 646 days (approximately 21 months), with a range of 8 to 4062 days. Five patients underwent a staged procedure, and no patients underwent a revision procedure for unsatisfactory results. CONCLUSIONS AND RELEVANCE Children with nasal obstruction and deformity can safely undergo nasal corrective surgery prior to adolescence. Special considerations include preserving normal structures and the judicious use of grafts. The recommended approaches to managing the pediatric septoplasty and nasal surgery patient are described herein through a series of representative cases.

Advances and innovations in brain arteriovenous malformation surgery

Arteriovenous malformations (AVMs) of the brain are very complex and intriguing pathologies. Since their initial description by Luschka and Virchow in the middle of the 19th century, multiple advances and innovations have revolutionized their management and surgical treatment. Here, we review the historical landmarks in the surgical treatment of AVMs and then illustrate the most recent and futuristic technologies aiming to improve outcomes in AVM surgeries. In particular, we examine potential advances in patient selection, imaging, surgical technique, neuroanesthesia, and postoperative neuro-rehabilitation and quantitative assessments. Finally, we illustrate how concurrent advances in radiosurgery and endovascular techniques might present new opportunities to treat AVMs more safely from a surgical perspective.

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.

Percutaneous transfacial direct embolization of an intraosseous dural arteriovenous fistula

BACKGROUND AND IMPORTANCE

An intraosseous dural arteriovenous fistula (DAVF) is a rare cerebrovascular disease. The fistulous connection occurs within intraosseous diploic or transosseous emissary veins causing dilated intraosseous vascular pouches. To the authors' knowledge, this report describes the first percutaneous transfacial direct embolization of an intraosseous DAVF.

CLINICAL PRESENTATION

A man in his 50s with blue rubber bleb nevus syndrome presented with headaches, imbalance, decreased visual acuity bilaterally, and left eye proptosis and chemosis. Imaging demonstrated an extensive intraosseous DAVF with dilated intraosseous vascular pouches throughout his cranial base and intraorbital venous congestion. He underwent staged endovascular treatment with the goal to improve his ocular symptoms. Transarterial and transvenous approaches failed to provide adequate access to the intraosseous vascular pouches. A direct, percutaneous transfacial approach was used to access the pouches for embolization with coils and liquid embolic material. Postoperative angiography demonstrated successful embolization of the pouch within the left pterygoid wing, reduced opacification of the intraosseous fistula, and elimination of intraorbital venous congestion. At 9-month follow-up, the patient's headaches had resolved, and his ocular symptomatology had improved.

CONCLUSION

Endovascular access to an intraosseous DAVF is limited by the size and location of the intraosseous vascular pouches. In this case, a direct transfacial approach under image guidance facilitated access and embolization, which led to an improvement in the patient's symptoms. This technique is a novel approach for DAVF management.

Endoscopic transcranial and intracranial resection: case series and design of a perioperative management protocol

Purely endoscopic resections of transcranial/intracranial pathology represent an exciting minimally invasive option for some patients. There is an abundance of literature on surgical techniques, though very little deals with perioperative management, which is critical for good outcomes. We present a detailed case review and a perioperative management protocol with specific reference to skull base and neuroanatomy. We performed a retrospective chart review and analysis of outcomes and complications by approach and design and prospective employment of a perioperative management protocol in a major tertiary care referral hospital. We included patients undergoing endoscopic skull base approaches by the two senior surgeons from September 2005 to April 2009, selecting of transcranial/intracranial cases for detailed review. Our main outcome measures included perioperative morbidity, mortality, and complications; degree of resection; recurrence rate; and survival. Fifteen patients met study criteria. No perioperative mortality occurred. There were two major and four minor complications. Mean follow-up was 15 months; 11/13 patients with malignancies had no evidence of disease. A perioperative management protocol was designed from these data and has resulted in decreased lumbar drainage and increased fluid/electrolyte monitoring. Endoscopic transcranial/intracranial anterior skull base surgery is both safe and effective when a complete understanding of the surgery and perioperative management is achieved.

Expanded endonasal endoscopic approach for resection of a skull base low-grade smooth muscle neoplasm

Benign smooth muscle tumors rarely occur in the head and neck and, to the best of our knowledge, have not been reported in the pterygopalatine fossa. In this report, we describe a 15-year-old adolescent who presented with facial pain and was found to have a large skull base tumor centered in the pterygopalatine fossa. The patient underwent an expanded endonasal endoscopic approach for complete resection of this lesion with resolution of his symptoms. Pathology revealed a well-differentiated smooth muscle neoplasm consistent with a leiomyoma. This case adds to the growing body of literature supporting a role for endoscopic procedures in the treatment of skull base pathologies in pediatric patients.

Endoscopic endonasal clipping of a ruptured vertebral-posterior inferior cerebellar artery aneurysm: technical case report

BACKGROUND AND IMPORTANCE

Aneurysms arising from the vertebral and posterior inferior cerebellar artery complex account for only 0.5 to 3% of all aneurysms. Surgery for these aneurysms is technically challenging because of the deep location and intimate relation with the medulla and lower cranial nerves. The authors report the case of a patient with a right vertebral-posterior inferior cerebellar artery complex (VA-PICA) aneurysm that was successfully clipped via an extended endoscopic endonasal transclival approach.

CLINICAL PRESENTATION

A 74-year-old woman with the sudden onset of severe headache, nausea, and vomiting was admitted to our hospital. A computed tomography (CT) of the brain revealed diffuse subarachnoid hemorrhage associated with intraventricular hemorrhage and incipient hydrocephalus. Cerebral angiography revealed a 1.2-mm aneurysm arising at the origin of the right PICA. The aneurysm was considered unsuitable for selective coil embolization, so neck clipping was performed. With the use of an extended endoscopic endonasal transclival approach, the aneurysm was accurately reached endoscopically and successfully clipped from the parent artery. The patient was discharged neurologically intact.

CONCLUSION

To the best of the authors' knowledge, this is the first report of a successfully treated VA-PICA ruptured aneurysm using a pure endoscopic endonasal transclival approach. Endoscopic surgery may be added to the armamentarium of procedures for the treatment of posterior circulation aneurysms.

[Shifting paradigm in skull base surgery: Roots, current state of the art and future trends of endonasal endoscopic approaches]

During the last two decades, endoscopic endonasal approach has completed the minimally invasive skull base surgery armamentarium. Endoscopic endonasal skull base surgery (EESBS) was initially developed in the field of pituitary adenomas, and gained an increasing place for the treatment of a wide variety of skull base pathologies, extending on the midline from crista galli process to the occipitocervical junction and laterally to the parasellar areas and petroclival apex. Until now, most studies are retrospective and lack sufficient methodological quality to confirm whether the endoscopic endonasal pituitary surgery has better results than the microsurgical trans-sphenoidal classical approach. The impressions of the expert teams show a trend toward better results for some pituitary adenomas with the endoscopic endonasal route, in terms of gross total resection rate and probably more comfortable postoperative course for the patient. Excepting intra- and suprasellar pituitary adenomas, EESBS seems useful for selected lesions extending onto the cavernous sinus and Meckel's cave but also for clival pathologies. Nevertheless, this infatuation toward endoscopic endonasal approaches has to be balanced with the critical issue of cerebrospinal fluid leaks, which constitutes actually the main limit of this approach. Through their experience and a review of the literature, the authors aim to present the state of the art of this approach as well as its limits.

Expanded endonasal approach for the clipping of a ruptured basilar aneurysm and feeding artery to a cerebellar arteriovenous malformation

While endovascular techniques play a significant and expanding role in the management of basilar trunk aneurysms, open surgical clipping remains necessary in select cases. Expanded endonasal transclival approaches offer the advantage of direct access and visualization of the midline vertebrobasilar system, benefits ideally suited to a basilar trunk aneurysm. A 59-year old woman with subarachnoid hemorrhage was found to have a ruptured basilar trunk aneurysm associated with a feeding vessel to a small cerebellar arteriovenous malformation (AVM). An expanded endoscopic endonasal transclival approach was used to successfully clip the basilar trunk aneurysm and feeding AVM vessel. The patient was subsequently discharged home without any neurological deficits. Transclival clipping of basilar trunk aneurysms is technically feasible and plays an important role in management when other strategies fail. The technical benefits of this approach include proximal and distal control of the basilar artery and improved visualization of the brainstem and perforators. Endoscopic transclival approaches should be considered in the management of complex basilar trunk aneurysms.

Pediatric endoscopic skull base surgery

PURPOSE OF REVIEW

Pediatric endoscopic skull base surgery (ESBS) has changed the current management of pediatric sinonasal and skull base disorders. This review focuses on the recent literature exploring pediatric ESBS, including its utility and limitations.

RECENT FINDINGS

Pediatric ESBS has been established as a safe and feasible technique for a variety of disease states. Special considerations in the pediatric populations include the use of image guidance technology, potential anatomic access limitations, and skull base reconstruction with vascularized flaps to prevent cerebrospinal fluid leak. The indications for endoscopic skull base surgery continue to expand as experience and technology evolve.

SUMMARY

Pediatric endoscopic skull base surgery is a proven technique established upon adult skull base experience. Despite certain limitations, the current literature would recommend consideration for this approach for many sinonasal and skull base lesions. Further research is required to determine long-term patient outcomes.

Endoscopic endonasal skull base surgery: analysis of complications in the authors' initial 800 patients

Object

The development of endoscopic endonasal approaches, albeit in the early stages, represents part of the continuous evolution of skull base surgery. During this early period, it is important to determine the safety of these approaches by analyzing surgical complications to identify and eliminate their causes.

Methods

The authors reviewed all perioperative complications associated with endoscopic endonasal skull base surgeries performed between July 1998 and June 2007 at the University of Pittsburgh Medical Center.

Results

This study includes the data for the authors' first 800 patients, comprising 399 male (49.9%) and 401 female (50.1%) patients with a mean age of 49.21 years (range 3–96 years). Pituitary adenomas (39.1%) and meningiomas (11.8%) were the 2 most common pathologies. A postoperative CSF leak represented the most common complication, occurring in 15.9% of the patients. All patients with a postoperative CSF leak were successfully treated with a lumbar drain and/or another endoscopic approach, except for 1 patient who required a transcranial repair. The incidence of postoperative CSF leaks decreased significantly with the adoption of vascularized tissue for reconstruction of the skull base (< 6%). Transient neurological deficits occurred in 20 patients (2.5%) and permanent neurological deficits in 14 patients (1.8%). Intracranial infection and systemic complications were encountered and successfully treated in 13 (1.6%) and 17 (2.1%) patients, respectively. Seven patients died during the 30-day perioperative period, 6 of systemic illness and 1 of infection (overall mortality 0.9%).

Conclusions

Endoscopic endonasal skull base surgery provides a viable median corridor based on anatomical landmarks and is customized according to the specific pathological process. This corridor should be considered as the sole access or may be combined with traditional approaches. With the incremental acquisition of skills and experience, endoscopic endonasal approaches have an acceptable safety profile in select patients presenting with various skull base pathologies.

Quality of postoperative course in children: endoscopic endonasal surgery versus sublabial microsurgery

BACKGROUND

The practice of endoscopic endonasal surgery is still limited in children because of the relative rarity of sellar lesions in the paediatric population. However, such an approach is increasingly reported in the literature as an alternative option to standard sublabial microsurgery, and its surgical results are being analysed. No information on the trend of the postoperative course is currently available. The goal of this paper is to assess the impact of these two different transsphenoidal approaches on the postoperative course.

METHODS

Thirty-one consecutive paediatric patients were treated for sellar region lesions by transsphenoidal surgery. Fourteen children (group A) underwent surgery with a microsurgical sublabial transsphenoidal approach between 2000 and 2005; the remaining 17 children (group B) underwent surgery with an endoscopic endonasal transsphenoidal approach between 2005 and 2009. The two groups were compared as to rate of admission to the PICU, relief from preoperative symptoms, early surgical complications, postoperative pain (Wong-Baker FACES Pain Scale) and length of postoperative hospital stay.

RESULTS

Children in group B showed decreased rates of admission to the PICU (35% versus 100%) and peroperative blood transfusions (23% versus 71%), and a shorter mean postoperative hospital stay (4 days versus 5.7 days). The pain perception was significantly lower in group B than in group A, as demonstrated by the scores registered during both the early (2.05 ± 0.74 versus 2.92 ± 0.91) and late postoperative period (0.82 ± 0.95 versus 1.64 ± 0.84). No remarkable differences in terms of operative time, symptom improvement and early complications were detected.

CONCLUSIONS

Endoscopic endonasal surgery can improve the quality of the postoperative course in children regardless of the type of lesions treated and the surgical complications.

Combined Endoscopic Endonasal Surgery and Fractionated Stereotactic Radiosurgery (fSRS) for Complex Cranial Base Tumors—Early Clinical Outcomes

Endoscopic endonasal surgery (EES) has been shown to be a feasible approach to cranial base tumors while reducing post-operative morbidity. Using the endoscopic endonasal approach alone or in combination with open approaches may provide advantages over conventional approaches. However, the balance between maximal resection and minimal injury to neurovascular structures frequently precludes gross total resection (GTR). Consequently, adjuvant radiation therapy may be an important option to improve local control (LC) of residual disease. In this retrospective series, we report clinical outcomes, morbidity, and LC of 40 patients with cranial base tumors treated with EES +/- combined open approach followed by fSRS (CyberKnife, Accuray Inc.). 26 patients had benign disease, 7 had newly diagnosed malignant disease, and 7 had previously resected malignant disease. Surgical outcomes were evaluable in all patients. LC after fSRS was evaluable in 39 patients and defined as no evidence of regrowth by MRI, CT, & physical examination. GTR was achieved in 12/40. Median post-operative length of stay (LOS) was 3 days. In multivariable analysis controlling for anatomic location and malignant histology, post-operative complications (n = 10) were significantly associated with patients having combined open and EES (p < 0.01, OR = 16.9). SRS was delivered in 1–5 sessions to a median marginal dose of 24.9 Gy. Median follow-up was 24.7 months (range, 1.5 to 61 months). LC was achieved in 89.7% (35/39) of evaluable patients. LC was achieved in 11/12 patients who had GTR. Median progression-free survival was 19.7 months (21.0 months for benign tumors (n = 26), 5.8 months for previously resected malignant disease (n = 7), and 21.2 months for newly diagnosed malignant disease (n = 7). Of the 31 patients who had symptomatic disease at presentation, 18 (58%) reported complete symptom resolution, 9 partial, and 4 no improvement. One patient who received two prior courses of radiation therapy developed osteosclerosis (grade III). Other adverse events were erythema (grade I, n = 5), nausea (grade II, n = 2), conjunctivitis (grade II, n = 1). EES followed by fSRS is a safe and effective management strategy for selected cranial base tumors. EES combined with an open surgical approach may result in increased complications. However, initial follow-up offers encouraging results indicating shorter time to recovery, acceptable LC rates compared to conventional approaches, and similar median time to progression for benign and newly diagnosed malignant disease.

Extensions of the sphenoid sinus: a new classification

OBJECTIVE

The transsphenoidal approach has been extended in recent years from tumors of the sellar region to lesions involving other areas bordering the sphenoid sinus including the cavernous sinus, Meckel's cave, middle cranial fossa, planum sphenoidal, suprasellar region, and clivus. The goal of this study was to examine various pneumatized extensions of the sphenoid sinus that may facilitate extended approaches directed through the sinus.

METHODS

The sphenoid sinus and its surrounding structures were examined in 18 cadaver heads, and the results were correlated with the findings from 100 computed tomography images of the sinus. The sellar type of the sphenoid sinus in which the pneumatization extended beyond the anterior sellar wall was further classified according to the various extensions of the sinus.

RESULTS

The sellar type of the sphenoid sinus was classified into the following 6 basic types based on the direction of pneumatization: sphenoid body, lateral, clival, lesser wing, anterior, and combined. The recesses and prominences, formed by pneumatization of the sinus, act as "windows" opening from the sinus in different areas of the cranial base and may facilitate minimally invasive access to lesions in the corresponding areas.

CONCLUSION

The variations in the extensions of pneumatization of the sphenoid sinus may facilitate entry into areas bordering the sphenoid sinus and play a role in the selection of a surgical approach to lesions bordering the sinus.

Endoscopic anatomy of the oculomotor nerve: defining the blind spot during endoscopic skull base surgery

OBJECTIVE

The objective of this study is to define the endoscopic anatomy of the oculomotor nerve (CN III) and its neurovascular relations in order to facilitate surgical procedures and avoid injury to this nerve during endoscopic endonasal approach to the skull base.

MATERIALS AND METHODS

Endoscopic anatomy of the cavernous sinus was studied in seven fresh adult cadavers bilaterally and the basal cisterns in five fresh adult cadavers. Extended endoscopic endonasal suprasellar approach was performed to expose the oculomotor nerve in the interpeduncular cistern and the endoscopic endonasal transethmoidopterygoidosphenoidal approach to expose the oculomotor nerve within the cavernous sinus.

RESULTS

The extraorbital part of the oculomotor nerve can be divided into three segments in regard to the cisterns and venous spaces that are being transected: the interpeduncular segment, the cisternal segment, and the intercavernous segment. Of these segments, only the cisternal segment could not be exposed since this segment was located at the initial part of the roof of the cavernous sinus, anterolateral to the posterior clinoid, and posteroinferior to the anterior clinoid processes. Thus, cisternal segment of the oculomotor nerve was considered a blind spot during endoscopic approaches to the skull base.

CONCLUSION

We defined the endoscopic anatomy of the CN III and the related neurovascular structures and proposed a new segmental classification of extraorbital oculomotor nerve. Awareness of the endoscopic anatomy and the new segmental classification of the CN III may prove helpful in avoiding the risk of nerve injury during endoscopic endonasal surgery for skull base pathologies.

Endoscopic endonasal transclival approach and retrosigmoid approach to the clival and petroclival regions

OBJECTIVE

The removal of clival lesions, mainly those located intradurally and with a limited lateral extension, may be challenging because of the lack of a surgical corridor that would allow exposure of the entire lesion surface. In this anatomic study, we explored the clival/petroclival area and the cerebellopontine angle via both the endonasal and retrosigmoid endoscopic routes, aiming to describe the respective degree of exposure and visual limitations.

METHODS

Twelve fresh cadaver heads were positioned to simulate a semisitting position, thus enabling the use of both endonasal and retrosigmoid routes, which were explored using a 4-mm rigid endoscope as the sole visualizing tool.

RESULTS

The comparison of the 2 endoscopic surgical views (endonasal and retrosigmoid) allowed us to define 3 subregions over the clival area (cranial, middle, and caudal levels) when explored via the endonasal route. The definition of these subregions was based on the identification of some anatomic landmarks (the internal carotid artery from the lacerum to the intradural segment, the abducens nerve, and the hypoglossal canal) that limit the bone opening via the endonasal route and the natural well-established corridors via the retrosigmoid route.

CONCLUSION

Different endoscopic surgical corridors can be delineated with the endonasal transclival and retrosigmoid approaches to the clival/petroclival area. Some relevant neurovascular structures may limit the extension of the approach and the view via both routes. The combination of the 2 approaches may improve the visualization in this challenging area.

Endoscopic transnasal approach to the clivus: a radiographic anatomical study

OBJECTIVES/HYPOTHESIS

Operative intervention of anterior skull base lesions is challenging. Various endoscopic surgical approaches have been described. The goal of the present study is to perform a radiographic analysis of the endoscopic transnasal approach to the clivus.

STUDY DESIGN

Anatomic study utilizing computed tomography (CT).

METHODS

High-resolution surgical-guidance CT images of the sinuses from 97 patients at a tertiary care medical center between 2002 and 2007 were evaluated. Axial and sagittal images were used to evaluate surgical access to the clivus. Multiple anatomical measurements were obtained and analyzed with imaging and statistical software.

RESULTS

Of the 97 imaging studies, there were 39 males and 58 females. The width of exposure of the clivus without removal of the septum was 2.7 cm (1.9-3.4 cm) and with removal of the bony septum was 3.6 cm (2.6-4.8 cm) (P < .001). No patients had complete exposure of the width of the clivus without the septum removed compared to 56 (58%) patients with the septum removed. Endoscopic exposure of the inferior and superior limits of the clivus was not limited in any images studied.

CONCLUSIONS

The endoscopic transnasal approach to the clivus is a viable option in the treatment of anterior skull base lesions with the preservation of functional anatomy in select patients. A large portion of the population has limited lateral exposure secondary to the eustachian tube and the medial pterygoid plate with an endoscopic transnasal approach. Vertically, this approach allows complete access to the clivus in all patients studied.

Endovascular treatment of epistaxis

Epistaxis is a common condition that can be managed conservatively in most cases. When these measures, including anterior and posterior packing of the nasal cavity, are unsuccessful at controlling the bleeding, interruption of the blood supply to the sinonasal area can be performed, either by surgical ligation or by transarterial embolization. Embolization should be preceded by thorough diagnostic angiography. Aside from aiding with subsequent selective catheterization and embolization, such angiography may reveal significant anatomic anomalies, anastomoses, or an unsuspected cause of epistaxis. Taking these findings into account, the interventionalist may decide to refrain from embolization or adjust the technique to minimize the risk of adverse events, which are mostly related to inadvertent embolization of the internal carotid artery or ophthalmic artery. We present a review of the various causes of epistaxis and the treatment options, with emphasis on endovascular embolization. We also describe the protocol of our institution for endovascular management of this condition.

Endoscopic endonasal pituitary transposition for a transdorsum sellae approach to the interpeduncular cistern

OBJECTIVE

The interpeduncular cistern, including the retroinfundibular area, is one of the most challenging regions to approach surgically. The pituitary gland and the infundibulum guard the region when an endonasal route is undertaken. Superior transposition of the pituitary gland and infundibulum is described as a functional means to access this complex region through a fully endoscopic, completely transnasal route.

METHODS

Ten consecutive patients in whom a pituitary transposition was performed during an expanded endonasal approach at the University of Pittsburgh Medical Center for resection of retroinfundibular lesions were reviewed. The series consisted of seven men and three women with a mean age of 44.4 years. Pathology consisted of four craniopharyngiomas, four chordomas, and two petroclival meningiomas.

RESULTS

Five patients (50%) underwent total resection of the tumor, three patients (30%) underwent near total resection ( > 95% removal), and two patients (20%) had partial resection of petroclival meningiomas with the goal of optic apparatus decompression. All four patients with visual deficits recovered their vision completely. There was no neurological deterioration. Eight patients had normal pituitary function preoperatively, seven of whom (87.5%) had confirmed function preservation postoperatively, with one of these patients experiencing transient diabetes insipidus. The remaining patient with a hypothalamic craniopharyngioma underwent complete resection with obligatory panhypopituitarism and diabetes insipidus.

CONCLUSION

Endoscopic endonasal transposition of the pituitary gland and its stalk can provide a valuable corridor to the retroinfundibular space and interpeduncular cistern with pituitary function preservation in the majority of patients. This approach should only be pursued once significant experience with endoscopic endonasal approaches has been acquired.

Endoscopic skull base surgery

Endoscopic skull base surgery has undergone rapid advancement in the past decade moving from pituitary surgery to suprasellar lesions and now to a myriad of lesions extending from the cribriform plate to C2 and laterally out to the infratemporal fossa and petrous apex. Evolution of several technological advances as well as advances in understanding of endoscopic anatomy and the development of surgical techniques both in resection and reconstruction have fostered this capability. Management of benign disease via endoscopic methods is largely accepted now but more data is needed before the controversy on the role of endoscopic management of malignant disease is decided. Continued advances in surgical technique, navigation systems, endoscopic imaging technology, and robotics assure continued brisk evolution in this expanding field.

Preoperative and intraoperative imaging for endoscopic endonasal approaches to the skull base

Endoscopic endonasal approaches are being used with increasing frequency to provide access to virtually any anterior cranial base, clival, or anterior craniocervical pathology. The radiographic evaluation of skull base anatomy and its relationship to associated tumors is critical for both preoperative planning and intraoperative guidance, to ensure the safety and efficacy of these techniques. CT and MRI play a complementary role in guiding endoscopic endonasal procedures.