EXTENDED ENDOSCOPIC ENDONASAL TRANSSPHENOIDAL APPROACH TO THE SUPRASELLAR AREA

Interest in using the extended endonasal transsphenoidal approach for management of suprasellar lesions, with either a microscopic or endoscopic technique, has increased in recent years. The most relevant benefit is that this median approach permits the exposure and removal of suprasellar lesions without the need for brain retraction. Fifteen human cadaver heads were dissected to evaluate the surgical key steps and the advantages and limitations of the extended endoscopic endonasal transplanum sphenoidale approach. We compared this with the transcranial microsurgical view of the suprasellar area as explored using the bilateral subfrontal microsurgical approach, and with the anatomy of the same region as obtained through the endoscopic endonasal route. Some anatomic conditions can prevent or hinder use of the extended endonasal approach. These include a low level of sphenoid sinus pneumatization, a small sella size with small distance between the internal carotid arteries, a wide intercavernous sinus, and a thick tuberculum sellae. Compared with the subfrontal transcranial approach, the endoscopic endonasal approach offers advantages to visualizing the subchiasmatic, retrosellar, and third ventricle areas. The endoscopic endonasal transplanum sphenoidale technique is a straight, median approach to the midline areas around the sella that provides a multiangled, close-up view of all relevant neurovascular structures. Although a lack of adequate instrumentation makes it impossible to manage all structures that are visible with the endoscope, in selected cases, the extended endoscopic endonasal approach can be considered part of the armamentarium for surgical treatment of the suprasellar area.

Background: Nowadays the endoscopic endonasal approach is increasingly being used to remove craniopharyngiomas, tuberculum sellae meningiomas and other presellar and parasellar lesions and its value in anterior skull base surgery is undisputed. Herein, we assess the relative advantages, disadvantages and feasibility of the keyhole eyebrow approach and the endonasal endoscopic approach in four cadaveric heads for the removal of presellar and parasellar lesions.Methods: We used four cadaveric heads for 12 surgical dissections. The specimens were embalmed with two different techniques. Two bilateral supraorbital endoscopic assisted approaches and one transnasal expanded endonasal approach were performed for each head. We evaluated the feasibility, maneuverability and safety of each approach. We measured the operating room obtained with each approach and the distance from the main structures we reached.Results: The technical feasibility of the endoscopic endonasal transphenoidal approach and the supraorbital eyebrow approach was reproduced in all four cadaveric heads. The transnasal approach gave us a good operating field medial to the two optic nerves and the two carotid arteries anteriorly until the frontal sinus and, posteriorly, the basilar artery, the emergence of the superior cerebellar arteries and posterior cerebral arteries. After performing the supraorbital approach, we viewed a wider field of the anterior skull base and we were able to reach the ipsilateral carotid artery, the optico-carotid recess, the pituitary stalk, the lamina terminalis until the contra lateral optic nerve and carotid artery, keeping a wider angle of maneuverability.Conclusions: Although the endoscopic transnasal approach has developed in leaps and bounds in the last decade, other transcranial approaches maintain their value. The supraorbital endoscopic approach is a minimally invasive approach and seems to be optimal for those lesions wider than 2 cm in the lateral extension and for all the paramedian lesions.

Introduction: Transpatial lesions involving the masticator, infratemporal, and preparotid spaces are challenging both to access and to resect due to their deep location, complex anatomy, and the multitude of important neurovascular structures they may contain. Traditionally, open approaches have been used to access these formidable spaces, resulting in good visualization for complete tumor resection but poor functional and cosmetic outcomes for the patient, even with removal of benign tumors. Recently, two "closed" approaches—the endoscopic endonasal approach and the transoral approach—have garnered increasing favorability as alternative methods for accessing and resecting lesions in these spaces. The major benefit of these minimally-invasive approaches is the reduced functional and cosmetic morbidity for the patient. However, visibility and instrument maneuverability can at times be limited when one of the minimally-invasive methods is used as the sole approach for tumor resection. We present a novel technique for resection of a large masticator, infratemporal, and preparotid space tumor using a combined endoscopic endonasal and transoral approach.

A comparative analysis of the endoscopic endonasal and pterional approaches for clipping anterior communicating artery aneurysms on three-dimensional printed models.

Transcranial anterior clinoidectomy is a conventional microsurgical approach for treatment of paraclinoid aneurysms. The endoscopic endonasal approach (EEA) is an alternative method for clipping intracranial aneurysms. No analysis has been conducted to anatomically compare approaches with respect to treating paraclinoid aneurysms. The surgical anatomical exposures of the paraclinoid region during transcranial extradural anterior clinoidectomy (EAC) and the endoscopic endonasal transplanum-cavernous approach (EETC) are described and quantitatively assessed. Seven cadaveric heads underwent EAC and EETC. Measurements included the area of exposure, volume of surgical freedom, angle of attack, ophthalmic artery (OphA) origin, and coronal exposure angle of the internal carotid artery (ICA). The EETC provided a larger area of exposure than the EAC (100.1±24.9 vs 76.1±12.9 mm2, p = 0.04). The EAC provided a higher volume of surgical freedom and greater angle of attack than the EETC in all neurovascular parameters, including the OphA, superior hypophyseal artery (SHA), distal ICA, and distal dural ring (all p < 0.001). The OphA origin was intradural in 85.7% and extradural in 14.3% of specimens. With regard to the coronal angle of exposure, the EAC exposed the OphA and SHA in the upper lateral quadrant (67.9±7.8° and 80.6±4.5°, respectively) and the distal ICA in the upper medial and upper lateral quadrants (92±7.5°). The EEA exposed the OphA, SHA, and distal ICA in the upper medial and lower medial quadrants (130.4±10.7°, 68.4±10.8°, and 58±11.4°, respectively). The EAC and EETC each offer specific advantages for paraclinoid region exposure. The EAC is appropriate for paraclinoid aneurysms that occur at the dorsolateral surface of the paraclinoid ICA. The EETC is an alternative approach for aneurysms that occur along medial surface of the paraclinoid ICA (e.g., carotid cave and SHA aneurysms). The EETC provides greater surgical exposure to the medial aspect of the paraclinoid ICA.

Endoscopic management of cerebrospinal fluid rhinorrhea

Introduction: The endoscopic endonasal approach (EEA) has granted robust access to midline skull base tumors, providing minimally invasive access to the anterior, middle, and posterior fossae as well as sinonasal and upper cervical regions. However, in the case of large masses with both midline and lateral extension, a single surgical approach can often be insufficient or overly morbid. This study demonstrates our experience with combining endonasal approaches with transcranial approaches—either simultaneously or in multiple stages—to effectively target extensive masses of the skull base.

Third ventricle craniopharyngioma (TVC) refers to the tumor originating from the tuberoinfundibular, and completely located in the third ventricle; unlike most TVCs, the retrochiasmatic-infundibulum corridor is too narrow to expose the tumor with anterior extension via an endoscopic endonasal approach. Retrospective analysis of two TVCs via an endoscopic endonasal combined pre-retrochiasmatic approach. The tumor inside the third ventricle can be satisfactorily exposed through a combined pre-retrochiasmatic approach and be completely removed with the lowest injury of the hypothalamus and optic nerve.

Background Traditionally, a pterional approach is utilized to access the Meckel cave. Depending on the tumor location, extradural dissection of the Gasserian ganglion can be performed. An endoscopic endonasal access could potentially avoid a craniotomy in these cases. Methods We performed an endoscopic endonasal approach as well as a lateral approach to the Meckel cave on six anatomic specimens. To access the Meckel cave endoscopically, a complete sphenoethmoidectomy and maxillary antrostomy followed by a transpterygoid approach was performed. For lateral access, a pterional craniotomy with extradural dissection was performed. Results The endoscopic endonasal approach allowed adequate access to the Gasserian ganglion. All the relevant anatomy was identified without difficulty. Both approaches allowed for a similar exposure, but the endonasal approach avoided brain retraction and improved anteromedial exposure of the Gasserian ganglion. The lateral approach provided improved access posterolaterally and to the superior portion. Conclusion The endoscopic endonasal approach to the Meckel cave is anatomically feasible. The morbidity associated with brain retraction from the open approaches can be avoided. Further understanding of the endoscopic anatomy within this region can facilitate continued advancement in endoscopic endonasal surgery and improvement in the safety and efficacy of these procedures.

Object In the last decade the indications for the endoscopic endonasal approach have been progressively expanded to include lesions that have not been traditionally considered amenable to resection through the transsphenoidal route. In this study, the authors analyze their experience with hypothalamic gliomas treated via the endoscopic endonasal approach. Methods Consecutive cases of hypothalamic gliomas treated since 2007 via an endoscopic endonasal approach were reviewed. Preoperative and postoperative neuroimaging as well as endocrinological, neurological, and visual symptoms were analyzed to assess the surgical outcome. Signs and symptoms of hypothalamic dysfunction including body mass index (BMI), memory, sleep-wake rhythm, and polyphagia were prospectively collected pre- and postoperatively to assess hypothalamic function. Quality of life was evaluated using the Katz scale. Results In the initial phase the endoscopic endonasal approach was adopted in 3 cases with a palliative intent, to obtain a biopsy sample or for debulking of the mass followed by radio- or chemotherapy. In 2 later cases it was successfully adopted to achieve gross-total tumor resection. Complications consisted of 2 postoperative CSF leaks, which required an endoscopic endonasal reintervention. Visual deficit improved in 3 cases and normalized in the other 2. Four patients developed diabetes insipidus, and 3 an anterior panhypopituitarism. All patients had a moderate increase in BMI. No patients presented with any other signs of hypothalamic damage, and their quality of life at follow-up is normal. Conclusions Despite the limitations of a short follow-up and small sample, the authors' early experience with the endoscopic endonasal approach has revealed it to be a direct, straightforward, and safe approach to third ventricle astrocytomas. It allowed the authors to perform tumor resection with the same microsurgical technique: dissecting the tumor with 2 hands, performing a central debulking, and controlling the bleeding with bipolar coagulation. The main limitations were represented by some anatomical conditions, such as the position of the chiasm and the anterior communicating artery complex and, finally, by the challenge of watertight plastic repair. To definitively evaluate the role of this approach in hypothalamic gliomas, a comparison with transcranial series would be necessary, but due to the rarity of these cases such a study is still lacking. The authors observed that more aggressive surgery is associated with a worse endocrinological outcome; thus they consider it to be an open question (in particular in prepubertal patients) whether radical removal is an advisable goal for hypothalamic gliomas.

Endonasal endoscopic approach (EEA) has become an integral part of neurosurgery, particularly for managing various pathologies involving the sellar and parasellar region and removing lesion in that area. But there is a rare condition in this area that not so common in literature is pituitary abscess (PA) after EEA for pituitary adenoma. A healthy 57-year-old man presented with a recurrent of bitemporal hemianopsia, persistent hypoadrenocorticism. In the history, he underwent two times of endonasal endoscopic transphenoid to remove pituitary adenoma. Magnetic resonance imaging (MRI) showed a sphenoid and sellar lesion with suprasellar extension and compression of the optic chiasm, with homogenous signal inside. Endoscopic transphenoid surgery was performed and the lesion was found is an abscess inside sphenoid and sellar with frank pus was obtained. But culture of the fluid was negative. After the operation, the patient was treated with antibiotics. His symptoms resolved after EEA, he improved visual field at this time but still in hypoadrenocorticism condition. An MRI was obtained after the operation to reveal that the lesion in sphenoid and sellar totally removed. We report on a rare case of a PA after two times of endonasal endoscopic transphenoid surgery of pituitary adenoma, and discuss the management of these conditions. We report a patient that came with us with recurrent of bitemporal hemianopsia and persistent hypoadrenocorticism. The patient undergone endonasal endoscopic sphenoid two times in the past. He didn't have clinical signs of infection. Imaging feature on MRI was high T2 and also high on T1 with homogenous signal inside with size 3.2 cm × 3.2 cm. Another EEA for this patient was performed to remove abscess and obtain pus from the lesion, but the result of culture was negative. He improved visual field but still in hypoadrenocorticism. In this case we report on a rare complication of transphenoid surgery, a PA progresses after EEA for a pituitary tumor. With this clinical experience, the correct diagnosis of PA before surgery, so it is a key leading to an exactly treatment for this condition. endonasal endoscopic transphenoid approach to drainage and removing abscess, and using antibiotics are necessary to improve the outcome of PA.

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.

Tumors involving Meckel cave (MC) always present challenges to neurosurgeons. We performed an investigation of the anatomical characteristics of the endoscopic endonasal transmaxillary transpterygoid approach to MC as an alternative to routine transcranial approaches and further confirmed its efficacy in the clinical setting. Five adult fresh head specimens (10 sides) were studied to identify crucial anatomical landmarks and quantify the anatomical structures involved in the endoscopic endonasal transmaxillary transpterygoid approach. Two patients with a tumor involving the left MC were treated using the endoscopic endonasal transmaxillary transpterygoid approach. The distance from the columella nasi to the choana, the sphenoid ostium, the anterior aperture of the palatosphenoidal canal (PSC), the sphenopalatine foramen, and the anterior aperture of the vidian canal (VC) was 66.5 ± 3.3 mm, 61.2 ± 1.6 mm, 64.6 ± 1.4 mm, 62.8 ± 2.3 mm, and 75.4 ± 3.3 mm, respectively. The distance from the anterior aperture of the VC to the anterior aperture of the PSC and the foramen rotundum (FR) was 2.1 ± 0.7 mm and 7.5 ± 0.7 mm, respectively; the length of the PSC and the VC was 6.4 ± 0.5 mm and 13.3 ± 1.2 mm, respectively. The landmarks of this route included the PSC, the VC, and the paraclival carotid prominence (CP). Subtotal resection and gross total resection were achieved in the first and second patients, respectively. The anatomical landmarks of the endoscopic endonasal transmaxillary transpterygoid route are useful for clinical application. The endoscopic endonasal transmaxillary transpterygoid approach is an effective and minimally invasive route for certain tumors involving MC. Identifying the anatomical landmarks including the PSC, the VC, the FR, and the CP is crucial for safe manipulation.

Simple SummarySkull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. Over time, several corridors have been proposed, each one carrying its own pros and cons. During the last decades, the endoscopic endonasal route has been asserted among the classic routes for a growing number of midline and paramedian lesions. Therefore, the aim of our paper is to present a comprehensive review of the indications and techniques for the management of skull base meningiomas, emphasizing the ambivalent and complementary role of the low and high routes.Skull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. The state of the art of skull base meningiomas accounts for both transcranial, or high, and endonasal, or low, routes. A comprehensive review of the pertinent literature was performed to address the surgical strategies and outcomes of skull base meningioma patients treated through a transcranial approach, an endoscopic endonasal approach (EEA), or both. Three databases (PubMed, Ovid Medline, and Ovid Embase) have been searched. The review of the literature provided 328 papers reporting the surgical, oncological, and clinical results of different approaches for the treatment of skull base meningiomas. The most suitable surgical corridors for olfactory groove, tuberculum sellae, clival and petroclival and cavernous sinus meningiomas have been analyzed. The EEA was proven to be associated with a lower extent of resection rates and better clinical outcomes compared with transcranial corridors, offering the possibility of achieving the so-called maximal safe resection.

The clinoidal venous space dorsal to the internal carotid artery (ICA) has not been well studied given its inaccessibility due to obstruction by the ICA during transcranial surgery. The evolution of endoscopic endonasal surgery has provided a new perspective into the clinoidal space and a new route for paraclinoidal lesions. Understanding the dorsal clinoidal space (DCS) is vital in planning and performing endoscopic endonasal surgery in the parasellar region. A detailed and precise description of the DCS from the endonasal perspective has not yet been provided. The authors' goal in this study was to delineate the microsurgical anatomy of the DCS from an endoscopic endonasal perspective, emphasizing its surgical implications when treating invasive pituitary adenomas and other parasellar lesions. An endoscopic endonasal transsellar approach was performed in 15 silicone-injected postmortem heads. Afterward, the sellar region was dissected through a transcranial approach using magnification ×3 to ×40 microscopy. The osseous, dural, and arterial relationships of the DCS and its architecture were investigated. The DCS's length, width, and depth were measured and its anatomical variations recorded. The DCS was identified in 90% of the specimens, and in most cases, its shape was a narrow rectangular pyramid, with its base oriented toward the sphenoid sinus and its apex toward the posterior clinoid process. It is delimited superiorly by the distal ring, inferiorly by the medial aspect of the proximal dural ring or caroticoclinoid ligament, laterally by the clinoidal ICA, and medially by the superior continuation of the medial wall of the cavernous sinus. The width, height, and length of the DCS were 4 ± 1, 4.5 ± 1.5, and 7 ± 2 mm, respectively. A fenestrated caroticoclinoid ligament is a potential route for tumor invasion from the cavernous sinus into the DCS. This report provides important anatomical descriptions of the DCS from endoscopic endonasal and transcranial perspectives that may facilitate the space's safe exposure for the removal of invasive adenomas, increasing total resection rates and minimizing the risk of injury to neurovascular structures.