E. Sauvaget

Endoscopic endonasal skull base surgery.

Skull base surgery has been transformed by the development of endoscopic techniques. Endoscopic procedures were first used for pituitary surgery and were then gradually extended to other regions. A wide range of diseases are now accessible to endoscopic skull base surgery. The major advantage of the endoscopic endonasal approach is that it provides direct anatomical access to a large number of intracranial and paranasal sinus lesions, avoiding the sequelae of a skin incision, facial bone flap or craniotomy, and brain retraction, which is inevitable with conventional neurosurgical incisions, resulting in decreased morbidity and mortality and, indirectly, decreased length of hospital stay and management costs. Moreover, the increasing number of publications in this field illustrates the growing interest in these techniques. This paper provides a review of endoscopic skull base surgery. The indications and general principles of endoscopic endonasal skull base surgery are described. Progress in exposure and especially reconstruction techniques is described. This progress now allows more extensive resections, while maintaining acceptable morbidity. The limits of this surgery are also discussed; in particular, although this surgery is often described as minimally invasive, it is not completely devoid of morbidity.

Transcribriform and transplanum endoscopic approach for skull-base tumors

European Annals of Otorhinolaryngology, Head and Neck Diseases - Vol. 130 - N° 4 - p. 233-236

Radionecrosis of the frontal lobe as a consequence of malignant ethmoid tumor management: incidence, diagnosis, risk factors, prevention and management

Malignant ethmoid tumors are treated by surgery followed by radiotherapy. This study aimed to evaluate the incidence, risk factors and outcome of radionecrosis of frontal lobe and determine preventive measures. Retrospective study of ethmoid malignancies treated from 2000 to 2011. All patients underwent surgery with/without anterior skull base resection using endoscopic or external approaches followed by irradiation (mean dose 64xa0Gy). Median follow-up was 50xa0months. Eight of 50 patients (16xa0%) presented with fronto-basal radionecrosis, connected to duraplasty, with a latent interval of 18.5xa0months. Although asymptomatic in six, radionecrosis triggered seizures and required surgery in two cases. Survival was not impacted. Risk factors included dyslipidemia, occurrence of epilepsy and dural resection. Radionecrosis may result from the combination of anterior skull base resection and radiotherapy for the treatment of ethmoid malignancies. Preventive measures rely on improving the duraplasty and optimization of the Gy-dose delivery.

Value of systematic analysis of the olfactory cleft in case of cerebrospinal rhinorrhea: incidence of olfactory arachnoid dilatation

To report on the presence of olfactory arachnoid dilatations (OAD), a previously undescribed radiologic feature of spontaneous cerebrospinal fluid (CSF) rhinorrhea originating from the cribriform plate of the ethmoid bone. The medical records of all patients treated between 2001 and 2011 at a tertiary care center for a spontaneous CSF rhinorrhea originating from the cribriform plate were retrospectively reviewed. The radiological work-up included high-resolution computed tomography and magnetic resonance imaging with at least the following sequences: T1, T2, and T2 with fast imaging employing steady state acquisition (FIESTA). Thirty cases were identified. The mean age at diagnosis was 49. Fourteen patients (47xa0%) had a body mass index (BMI) of 30 or more and 3 patients (10xa0%) had a BMI between 25 and 29.9. Five patients had a history of meningitis. The imaging work-up revealed a bone defect of the cribriform plate in 6 cases (20xa0%), associated to a typical meningocele in 14 cases (47xa0%). In ten patients (33xa0%), there was no defect of the cribriform plate, but ultrathin coronal T2-FIESTA sequences revealed an OAD, i.e. a dilatation of the arachnoid sheath of the olfactory fibers, in nine cases (30xa0%), or a “pseudo-polyp” outlined by a thin layer of arachnoid (1 patient, 3xa0%). Preoperative imaging should be carefully analyzed for the presence of OAD or “pseudo-polyp” in patients presenting with a CSF rhinorrhea without bony defect of the cribriform plate.

Exposure techniques in endoscopic skull base surgery: Posterior septectomy, medial maxillectomy, transmaxillary and transpterygoid approach

European Annals of Otorhinolaryngology, Head and Neck Diseases - Vol. 129 - N° 5 - p. 284-288

Chirurgia del fibroma nasofaringeo

Il trattamento di riferimento del fibroma nasofaringeo rimane l’exeresi chirurgica. I progressi compiuti nel settore della diagnostica per immagini, dell’embolizzazione selettiva e della strumentazione hanno permesso di ridurre notevolmente la morbilita legata alla chirurgia di questo tumore ipervascolarizzato. Anche le tecniche chirurgiche sono progredite. Attualmente, le vie d’accesso endoscopiche endonasali permettono, nella maggior parte delle situazioni, di ottenere un’exeresi di qualita, limitando al tempo stesso le sequele estetiche e funzionali. I tumori limitati alla fossa pterigopalatina e alla fossa nasale sono stati i primi a essere operati per via endonasale. I miglioramenti nel settore dell’esposizione (resezione del setto, maxillectomia mediale), delle vie transmascellari e delle vie transpterigoidee permettono di gestire dei tumori estesi alla fossa infratemporale, alla regione dell’apice petroso, al forame lacero e al clivus. Anche alcune estensioni intracraniche limitate (forame rotondo e ovale, planum sfenoidale, lamina cribrosa) sono accessibili a un’exeresi endoscopica. Un accesso esterno resta comunque indispensabile in alcune situazioni: invasione intracranica importante, inguainamento dell’arteria carotide interna, estensione molto laterale alla fossa temporale al di sopra dello zigomo ed estensione tumorale posteriormente o lateralmente al nervo ottico. Quando la resezione completa provoca una morbilita giudicata inaccettabile, puo, talvolta, essere lasciato in sede un frammento tumorale. In tutti i casi, il monitoraggio postoperatorio passa attraverso una diagnostica per immagini precoce, per individuare e trattare un eventuale residuo tumorale passato inosservato, poi attraverso un follow-up clinico e radiologico prolungato.

Cirugía del fibroma nasofaríngeo

El tratamiento de referencia del fibroma nasofaringeo sigue siendo la reseccion quirurgica. Los progresos realizados en el ambito de las pruebas de imagen, de la embolizacion selectiva y del instrumental han permitido reducir de forma notable la morbilidad relacionada con la cirugia de este tumor hipervascularizado. Las tecnicas quirurgicas tambien han evolucionado. En la actualidad, las vias de acceso endoscopicas endonasales permiten lograr una reseccion de calidad en la mayoria de las ocasiones, a la vez que restringen las secuelas esteticas y funcionales. Los tumores limitados a la fosa pterigopalatina y a la fosa nasal han sido los primeros en operarse por via endonasal. Los avances en el ambito de la exposicion (reseccion del tabique, maxilectomia medial), las vias transmaxilares y las vias transpterigoideas permiten tratar los tumores extendidos a la fosa infratemporal, a la region del vertice petroso, al agujero rasgado y al clivus. Algunas extensiones intracraneales limitadas (agujeros redondo y oval, yugo esfenoidal, lamina cribosa) tambien son accesibles a la reseccion endoscopica. Sin embargo, en algunas situaciones sigue siendo indispensable un acceso externo: invasion intracraneal extensa, tumor que rodea la arteria carotida interna, extension muy lateral a la fosa temporal por encima del cigoma, extension tumoral por detras o lateralmente al nervio optico. Cuando la reseccion completa provoca una morbilidad que se considera inaceptable, en ocasiones se puede dejar in situ un fragmento tumoral. En todos los casos, la vigilancia postoperatoria consiste en la realizacion precoz de pruebas de imagen, para detectar y tratar un posible resto tumoral que haya pasado desapercibido. Despues, debe llevarse a cabo un seguimiento clinico y radiologico prolongado.