Pericallosal Aneurysms: Effectiveness of Endovascular Management

Objective Clarify the safety and efficacy of the endovascular treatment of distal anterior cerebral artery (DACA) aneurysms, reporting outcomes of the aneurysms coiled in our service were compared with series of microsurgical treatment. The impact of embolization on ruptured or unruptured aneurysms remains controversial according to the current data, considering aneurysm from this topography should be aggressively treated due to their high incidence of rupture, currently there is a tend to prefer endovascular treatment. Methods We conducted a retrospective cohort study with 1092 patients admitted with cerebral aneurysm from October 2005 to March 2015 in our service. There were 31 cases of DACA aneurysms treated with the endovascular technique. These were compared with same topography aneurysms underwent to clipping. Results A total of 21 (67%) of 31 cases presented with ruptured aneurysms, 13 (59%) suffered clinical or radiological vasospasms, with modified Rankin Scale (mRS) scores of 3­5 in 7 patients (31%), and 4 deaths (mRS 6), reaching 92% of occlusion at one year. Conclusion Endovascular approach is associated with high angiographic occlusion rates and security.

Objetivo Para esclarecer a segurança e eficácia do tratamento endovascular dos aneurismas distais da artéria cerebral anterior distal (DACA), foram relatados os resultados de aneurismas embolizados em nosso serviço e comparados com séries de tratamento microcirúrgico. O impacto da embolização em aneurisma roto ou não roto permanece controverso com base nos dados atuais, considerando que o aneurisma dessa topografia deve ser tratado agressivamente devido à elevada incidência de ruptura, há uma tendência em preferir tratamento endovascular. Métodos Realizamos um estudo retrospectivo de 1092 pacientes admitidos com aneurisma cerebral entre Outubro de 2005 a Março de 2015 em nosso serviço. Haviam 31 casos de aneurisma da DACA tratados com a técnica endovascular. Estes foram comparados com aneurismas da mesma topografia tratados através de microcirurgia. Resultados Um total de 21 (67%) dos 31 pacientes apresentaram aneurisma roto, 13 (59%) sofreram vasoespasmo clínico ou radiológico, desfecho Escala de Rankin modificada (ERm) 3­5 em 7 (31%) pacientes e 4 mortes (ERm 6). A taxa de oclusão imediata foi de 96% e a taxa de oclusão em um ano de 92% com apenas uma recanalização. Conclusão A abordagem endovascular está associada com altas taxas de oclusão angiográfica e segurança no procedimento.

Advantages and limitations of endoscopic endonasal approaches to the skull base.

BACKGROUND: The anatomy of the skull base is extremely complex with an abundance of critical neurovascular bundles and their corresponding foramina as well as the insertions and origins of multiple masticatory and craniocervical muscles. These anatomic intricacies increase the difficulty of surgery within this area. METHODS: Advantages and disadvantages of endoscopic endonasal approaches (EEAs) based on the authors' sequential learning and experience are described. RESULTS: EEAs offer the advantages of using preexistent air spaces that enable accessing various areas of the skull base, while avoiding external incisions or scars and obviating the need for the translocation of the maxillofacial skeleton. In addition, EEAs are well suited to preserve neurologic, visual, and masticatory functions as well as cosmesis. However, the sinonasal corridor must be expanded and optimized to access the skull base adequately, facilitate the reconstruction of the surgical defect, avoid sinonasal complications, and minimize sequelae. Important considerations can limit or indicate the approach, such as the nature of the pathology, including location, diagnosis, and vascularity; patient characteristics, including age and medical comorbidities; surgeon attributes, including training, experience, and expertise; the resultant need to reconstruct large skull base defects and feasible alternatives to do so; and institutional resources, including adjunctive services, an intensive care unit, and operating room equipment. CONCLUSIONS: EEAs are important techniques in contemporary skull base surgery. Understanding the indications for and limitations of these approaches help to maximize outcomes.

Endonasal endoscopic approaches to the paramedian skull base.

OBJECTIVE: To describe the technical and anatomic nuances related to endoscopic endonasal approaches (EEAs) to the paramedian skull base. METHODS: Surgical indications, limitations, and technical aspects pertaining to EEAs designed to access areas oriented in the coronal plane are systematically reviewed with special attention to caveats, pitfalls, and common complications and how to avoid them. Case examples are presented. RESULTS: The paramedian skull base may be divided into anterior (corresponding to the orbit and its contents), middle (corresponding to the middle cranial, pterygopalatine, and infratemporal fossae), and posterior (includes the craniovertebral junction lateral to the occipital condyles and the jugular foramen) segments. EEAs to the anterior segment offer access to the intraconal orbital space and the optic canal. A transpterygoid corridor typically precedes EEAs to the middle and posterior paramedian approaches. EEAs to the middle segment provide wide exposure of the petrous apex, middle cranial fossa (including cavernous sinus and Meckel cave), and infratemporal and pterygopalatine fossae. Finally, EEAs to the posterior segment access the hypoglossal canal, occipital condyle, and jugular foramen. CONCLUSIONS: Approaches to the paramedian skull base are the most challenging and complex of all endoscopic endonasal techniques. Because of their technical complexity, it is recommended that surgeons master endoscopic endonasal anatomic approaches oriented to median structures (sagittal plane) before approaching paramedian (coronal plane) pathologies.

Volumetric analysis of endoscopic and traditional surgical approaches to the infratemporal fossa.

OBJECTIVES/HYPOTHESIS: In an effort to decrease morbidity, skull base surgeons have explored less invasive approaches to the infratemporal fossa, including endonasal-endoscopy, minicraniotomies, and transantral endoscopic and microscopic corridors. This project presents quantitative data that assesses the practicality, and volumetric exposure afforded by endonasal and open approaches to the infratemporal fossa. STUDY DESIGN: First, the study defines the anatomy of endoscopic-endonasal and preauricular approaches to the infratemporal fossa. Subsequently, the study involved the calculation of anatomical volumes using cadaveric and virtual models. METHODS: Computed tomography (CT) scanning of two anatomical specimens served to recreate computer simulations of the endonasal and preauricular approaches, allowing for the assessment of the infratemporal fossae volumes. In addition, the dissections served to identify and mark critical surgical landmarks and boundaries. A second CT scan, after the surgical dissection, allowed for a reanalysis of the data for a volumetric comparison of the surgical approaches. RESULTS: Pre- and postdissection CT scans and computer simulations revealed that volumes in the open and endonasal approaches to the infratemporal fossa are strikingly similar, suggesting that volumes of surgical instrumentation and visualization may also be comparable. However, the entry gate for instrumentation differed significantly for each approach. CONCLUSION: This study suggests that, although the entry gate for instrumentation is greater during an open approach, contrary to intuition, an open approach does not create a substantially larger working space or visual field. Analysis of volumetric measurements facilitates a better understanding of the indications for each procedure.

Extracapsular dissection technique with the cotton swab for pituitary adenomas through an endoscopic endonasal approach -- how I do it.

BACKGROUND: Pituitary adenomas are often encased in a histological pseudocapsule that separates the tumor from the normal gland. Transsphenoidal adenoma resection may be performed either in an intra- or an extracapsular technique. The extracapsular fashion offers anatomical orientation, removal of a security margin, reduced risk of opening the arachnoid layer with subsequent CSF flow and identification of invasion. METHOD: The sella turcica is approached through the classic endoscopic endonasal route. After opening the dura of the sellar floor, the interface between the compressed tissue and the normal gland is used as a surgical plane for dissection. Performing slight counter-traction with the suction tube, the cleavage plane is identified and stepwise unsealed in an atraumatic fashion with the cotton swab. Once the cleavage plane is partially loosened, repeated twisting movements are performed with the cotton swab to enucleate the pseudocapsule and adenoma. CONCLUSION: Both micro- and macroadenomas presenting a pseudocapsule may be resected in the extracapsular dissection technique with the cotton swab. Operating in an endoscopic three- to four hands technique enables to visualize the anatomic planes and perform twisting movements with the cotton swab separating pseudocapsule and tumor in order to enucleate the adenoma.

Combined transoral robotic surgery and endoscopic endonasal approach for the resection of extensive malignancies of the skull base.

BACKGROUND: Oncologic resection of the clivus, nasopharynx, craniovertebral junction, and infratemporal fossa is a challenging endeavor because of their complex and protected anatomy. Our goals were to design a cadaveric model and identify advantages and limitations of combining the transoral robotic surgery (TORS) and endoscopic endonasal approach (EEA) techniques. METHODS: Cadaveric specimens were dissected using a da Vinci surgical robot and endoscopic endonasal instruments in a fashion that mimicked our operating room environment. We then applied these techniques clinically. RESULTS: EEA was performed to provide a detailed dissection of the infratemporal fossa, nasopharynx, posterior skull base (clivus), and craniovertebral junction. Using TORS, we dissected the parapharyngeal space, infratemporal fossa, and nasopharynx below the eustachian tube, which represented a transition zone that delineated the most effective resection field of each approach. CONCLUSIONS: TORS and EEA seem to be complementary techniques; thus, their combined use seems advantageous for selected advanced tumors in these complex areas.

Surgical management of craniopharyngioma with third ventricle involvement.

Craniopharyngiomas are notorious for their ability to invade the hypothalamus and third ventricle. Although several transcranial approaches have been proposed for their treatment, the endonasal route provides direct access to the tumor with no need for cerebral retraction or manipulation of the optic apparatus. After the lesion is debulked, the unique angle of approach achieved with this technique enables the surgeon to perform an extra-capsular dissection and visualize the walls of the third ventricle, the foramina of Monro, and the anterior comissure. Moreover, the enhanced magnification and lighting afforded by the endoscope facilitate safe tumor removal, particularly in areas where there is loss of clear lesion delimitation and greater infiltration of the surrounding structures. Herein we present the case of a 68-year-old female patient with a 3-month history of visual deterioration accompanied by worsening headaches. Investigation with magnetic resonance imaging revealed a heterogeneous mass in the suprasellar region, extending into the third ventricle and displacing the pituitary gland and stalk inferiorly. Hormonal profile was within expected range for her age. An endonasal, fully endoscopic, transplanum transtuberculum approach was performed. Gross-total removal was achieved and pathology confirmed the diagnosis of craniopharyngioma. Postoperative recovery was marked by transient diabetes insipidus. Closure was achieved with a pedicled nasoseptal flap; despite exploration of the third ventricle, there was no cerebrospinal fluid leakage. Pituitary function was preserved. Visual function has fully recovered and the patient has been uneventfully followed since surgery. The video can be found here: http://youtu.be/it5mpofZl0Q. (http://thejns.org/doi/abs/10.3171/2013.V1.FOCUS12330)

Endoscopic treatment of a third ventricle choroid plexus cyst.

Choroid plexus cysts are frequent benign intraventricular lesions that infrequently cause symptoms, usually in the form of obstructive hydrocephalus. These instances are even less common in the adult population. When warranted, treatment seeks to reestablish cerebrospinal fluid flow and does not necessarily require resection of the cyst itself. Hence, endoscopic exploration of the ventricles with subsequent cyst ablation is the current treatment of choice for these lesions. Herein we present the case of a 25-year-old female patient with a 3-week history of intermittent headaches. Investigation with computerized tomography (CT) of the head detected supratentorial hydrocephalus, with enlargement of the lateral and third ventricles. Magnetic resonance imaging revealed a homogeneous cystic lesion in the third ventricle. A right-sided, pre-coronal burr hole was carried out, followed by endoscopic exploration of the ventricular system. A third-ventriclostomy was performed. With the aid of the 30-degrees endoscope, a cyst arising from the choroid plexus was visualized along the posterior portion of the third ventricle, obstructing the aqueduct opening. The cyst was cauterized until significant reduction of its dimensions was achieved and the aqueduct opening was liberated. Postoperative recovery was without incident and resolution of the hydrocephalus was confirmed by CT imaging. The patient reports complete improvement of her headaches and has been uneventfully followed since surgery. The video can be found here: http://youtu.be/XBtj_SqY07Q. (http://thejns.org/doi/abs/10.3171/2013.V1.FOCUS12332)

Application of image guidance in pituitary surgery.

BACKGROUND: Surgical treatment of pituitary pathologies has evolved along the years, adding safety and decreasing morbidity related to the procedure. Advances in the field of radiology, coupled with stereotactic technology and computer modeling, have culminated in the contemporary and widespread use of image guidance systems, as we know them today. Image guidance navigation has become a frequently used technology that provides continuous three-dimensional information for the accurate performance of neurosurgical procedures. We present a discussion about the application of image guidance in pituitary surgeries. METHODS: Major indications for image guidance neuronavigation application in pituitary surgery are presented and demonstrated with illustrative cases. Limitations of this technology are also presented. RESULTS: Patients presenting a history of previous transsphenoidal surgeries, anatomical variances of the sphenoid sinus, tumors with a close relation to the internal carotid arteries, and extrasellar tumors are the most important indications for image guidance in pituitary surgeries. The high cost of the equipment, increased time of surgery due to setup time, and registration and the need of specific training for the operating room personnel could be pointed as limitations of this technology. CONCLUSION: Intraoperative image guidance systems provide real-time images, increasing surgical accuracy and enabling safe, minimally invasive interventions. However, the use of intraoperative navigation is not a replacement for surgical experience and a systematic knowledge of regional anatomy. It must be recognized as a tool by which the neurosurgeon can reduce the risk associated with surgical approach and treatment of pituitary pathologies.