[Transzygomatic pterional approach. Part 2: Surgical experience in the management of skull base pathology]. / Abordaje pterional transcigomático. Parte 2: Experiencia quirúrgica en la patología de base de cráneo.

OBJECTIVES: To present our experience with the transzygomatic pterional approach in the treatment of neurosurgical pathology of the base of the skull located in the middle cranial fossa and surrounding areas. METHOD: A retrospective study of pathological findings, surgical outcomes and complications in a series of 31 cases operated on between 2009 and 2011 using a transzygomatic pterional approach. RESULTS: The lesions involved the sphenoid wing (25.9%), several regions due to invasive growth pattern (19.5%), the temporal lobe (16.1%) and cavernous sinus (12.9%). The others were located in the floor of the middle fossa, Meckel's cave, incisural space, cisterns and infratemporal region. The pathological nature of the lesions was: benign meningioma (42%), temporal lobe tumour (19.5%), vascular disease (12.9%), inflammatory lesions (6.4%), atypical meningioma (6.4%), epidermoid cyst (6.4%), neurinoma (3.2%) and poorly differentiated infratemporal carcinoma (3.2%). The approach was usually combined extra-intradural (58.1%) and, less frequently, just extradural (16.1%) or intradural (25.8%). Approach-related complications were minor: haematomas in the wound not requiring treatment (67.8%), superior transient facial paresis (9.7%), transient temporomandibular joint dysfunction (12.9%) and atrophy of the temporal muscle (16.2%). There were no hardware-related complications or cosmetic issues related to the osteotomy and posterior osteosynthesis of the zygomatic arch. CONCLUSIONS: The pterional approach combined with osteotomy of the zygomatic arch allows mobilising the temporalis muscle away from the temporal fossa, consequently exposing its entire surface to complete the temporal craniotomy up to the middle fossa; it helps to access and treat pathology in this region or it can be used as a corridor to approach surrounding areas.

[Transzygomatic pterional approach. Part 1: anatomical study]. / Abordaje pterional transcigomático. Parte 1: estudio anatómico.

OBJECTIVE: Cadaveric study of the anatomical structures of the temporal region, as well as the technical aspects of the transzygomatic pterional approach. MATERIAL AND METHODS: Six human formalin-fixed heads, whose arterial circulatory system was injected with red-dyed silicone, were studied (12 temporal regions). Dissections were performed using standard microsurgical techniques and instruments. RESULTS: We confirm the existence of a double superficial and deep layer within the superficial temporal fascia, which makes possible to perform the zygomatic arch osteotomy without damaging the temporal muscle and the branches of the superficial temporal artery and the facial nerve. The shape and location of the osteotomies to preserve the témporo-mandibular joint and ligaments and to provide correct reconstruction of the bone flap are described. We compare the exposure of intracranial structures obtained by this approach with those obtained by the conventional pterional approach and the orbitozygomatic approach. CONCLUSIONS: The transzygomatic pterional approach provides wide exposure of the temporal lobe for trans-sylvian, pre-temporal and/or subtemporal approaches in selected cases of neurosurgical pathology. A detailed anatomical knowledge of the temporal region is necessary to achieve the best surgical, functional and cosmetic results.

Abordaje pterional transcigomático. Parte 2: Experiencia quirúrgica en la patología de base de cráneo / No disponible

Objetivos Exponer la experiencia con el abordaje pterional transcigomático en el tratamiento de la patología neuroquirúrgica de la base de cráneo situada en la fosa craneal media y zonas vecinas. Material y método Estudio retrospectivo de la patología, resultados quirúrgicos y complicaciones obtenidos en 31 casos intervenidos entre 2009 y 2011 usando un abordaje pterional transcigomático. Resultados Se han intervenido lesiones del ala del esfenoides (25,9%), afectando varias regiones por su crecimiento invasivo (19,5%), del lóbulo temporal (16,1%) y del seno cavernoso (12,9%), involucrando el resto al suelo de la fosa media, cavum de Meckel, región incisural, cisternas y región infratemporal. La naturaleza de las lesiones intervenidas fue la siguiente: meningioma benigno (42%), tumor parenquimatoso (19,5%), patología vascular (12,9%), lesiones inflamatorias (6,4%), meningioma atípico (6,4%), tumor epidermoide (6,4%), neurinoma (3,2%) y carcinoma pobremente diferenciado infratemporal (3,2%). La mayor parte de las veces el abordaje fue combinado extra-intradural (58,1%), y con menor frecuencia extradural (16,1%) o intradural (25,8%) puro. Las complicaciones relacionadas con el abordaje fueron menores: hematomas en la herida que no requirieron tratamiento (67,8%), paresia facial superior transitoria (9,7%), de disfunción transitoria de articulación temporomandibular (12,9%) y atrofia del músculo temporal (16,2%). No hubo ningún caso de aflojamiento de material ni problemas estéticos relacionados con la osteotomía y osteosíntesis del arco cigomático. Conclusiones La modificación del abordaje pterional asociando una osteotomía del arco cigomático, que permite rebatir el músculo temporal de toda la fosa temporal y exponer así toda su superficie para completar la craneotomía temporal hasta la base de la fosa media, nos facilita el acceso para tratar patología de la misma o utilizarla como corredor para el acceso a zonas vecinas (AU)

Abordaje pterional transcigomático. Parte 1: estudio anatómico / Transzygomatic pterional approach. Part 1: anatomical study

Objetivo: Estudio cadavérico de las estructuras anatómicas de la región temporal, así como de los aspectos técnicos del abordaje pterional transcigomático. Material y métodos: Fueron utilizados 6 especímenes cadavéricos (12 regiones temporales) previamente formolizados, cuyo sistema circulatorio arterial fue inyectado con silicona teñida de rojo. Las disecciones se realizaron utilizando el instrumental y la técnica microquirúrgica estándar. Resultados: Se confirma la existencia de una doble capa superficial y profunda en la fascia temporal superficial, lo que permite la osteotomía cigomática respetando la integridad del músculo temporal y de las ramas de la arteria temporal superficial y del nervio facial. Se detallan las líneas de la osteotomía para preservar la articulación témporo-mandibular y una correcta reposición del colgajo óseo. La exposición de estructuras intracraneales obtenida mediante dicho abordaje se compara favorablemente con aquellas obtenidas mediante el abordaje pterional convencional y el abordaje órbito-cigomático. Conclusiones: El abordaje pterional transcigomático ofrece una amplia exposición del lóbulo temporal para la realización de abordajes transsilvianos, pretemporales y/o subtemporales en casos seleccionados de patología neuroquirúrgica. Es necesario un detallado conocimiento anatómico de la región temporal para obtener los mejores resultados quirúrgicos, estéticos y funcionales (AU)

Objective: Cadaveric study of the anatomical structures of the temporal region, as well as the technical aspects of the transzygomatic pterional approach. Material and methods: Six human formalin-fixed heads, whose arterial circulatory system was injected with red-dyed silicone, were studied (12 temporal regions). Dissections were performed using standard microsurgical techniques and instruments. Results: We confirm the existence of a double superficial and deep layer within the superficial temporal fascia, which makes possible to perform the zygomatic arch osteotomy without damaging the temporal muscle and the branches of the superficial temporal artery and the facial nerve. The shape and location of the osteotomies to preserve the témporo-mandibular joint and ligaments and to provide correct reconstruction of the bone flap are described. We compare the exposure of intracranial structures obtained by this approach with those obtained by the conventional pterional approach and the orbitozygomatic approach. Conclusions: The transzygomatic pterional approach provides wide exposure of the temporal lobe for trans-sylvian, pre-temporal and/or subtemporal approaches in selected cases of neurosurgical pathology. A detailed anatomical knowledge of the temporal region is necessary to achieve the best surgical, functional and cosmetic results (AU)

Microsurgical Relations between Internal Carotid Artery-Posterior Communicating Artery (ICA-PComA) Segment Aneurysms and Skull Base: An Anatomoclinical Study.

Purpose The study of the clinical, anatomic, imaging, and microsurgical characteristics of the aneurysms of the internal carotid-posterior communicating artery (ICA-PComA) segment and their relationships with the skull base structures. Methods The anatomic relationships of PComA with neurovascular elements and skull base structures were studied in cadavers. The clinical, imaging, and microsurgical findings of 84 microsurgically treated ICA-PComA aneurysms compiled in a prospective database were reviewed. Results The most important anatomic relations of the PComA and ICA-PComA aneurysms are with the oculomotor nerve around the oculomotor triangle that forms the roof of the cavernous sinus. Aneurysms of the ICA-PComA are classified according to the orientation of the aneurysmal sac in infratentorial, supratentorial, and tentorial. Infratentorial aneurysms frequently present with subarachnoid hemorrhage (SAH) and oculomotor nerve paralysis. They have relations with skull base structures that often make it necessary to totally or partially resect the anterior clinoid process (6.7%) or anterior petroclinoid dural fold (15%). Supratentorial aneurysms course with SAH and without oculomotor nerve involvement, but they often are associated with intracranial hematoma. Conclusion ICA-PComA aneurysms have complex anatomic relations. The orientation of the aneurysmal fundus induces relevant differences in the anatomic relations, clinical presentation, and microsurgical approach to ICA-PComA aneurysms.