Acesso retrossigmoideo versus petroso posterior: análise comparativa anatomocirúrgica de duas abordagens assistidas por endoscopia à região petroclival

Abstract

Palavras-chave: Acesso petroso. Acesso retrossigmoideo. Base de crânio. Lesão petroclival. Neuroendoscopia.ABSTRACT COELHO JR., V. P. M. Retrosigmoid versus posterior petrosal approach: anatomosurgical comparative analysis of two endoscope-assisted approaches to the petroclival region. 2019. 98 f. Thesis (Doctorate) -Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, 2019.The petroclival region bears anatomical peculiarities that add more complexity to its surgical approach, representing an important challenge in skull base surgery. The conjugation of the endoscope to the classic microscopy has been consolidating modernly, being able to help greatly in this context. However, with different accesses proposed for this anatomical area, of which retrosigmoid and posterior petrous stand out, the literature lacks more robust evidence to determine criteria that guide the choice of a particular approach, making it important to investigate which route to the target-area this device allows the best result. Using a cadaveric model, we aimed to compare posterior petrosal and retrosigmoid approaches, both with endoscopic assistance, regarding surgical exposure and maneuverability, as well as to verify whether the petroclival angle and clival depth interfere in these variables. In five cadaveric heads, a retrosigmoid approach was performed on one side and a retrolabirynthine posterior petrosal on the other (10 approaches). Under endoscopic view, coordinates were acquired by neuronavigation to calculate the surgical exposure area (petroclival and pontomedullary) and maneuverability to allow comparisons. Correlations of these variables with petroclival angle and clival depth were also studied. In this model, the approaches showed equivalence regarding surgical exposure, but retrosigmoid afforded significantly greater maneuverability. The petroclival angle and clival depth correlate with maneuverability, but not with surgical exposure in both endoscope-assisted approaches. Endoscope-assisted techniques allow adequate petroclival exposure in these approaches, which may spare the need for additional surgical steps of greater morbidity. Using neuroendoscopy, the retrosigmoid approach might show some advantage over posterior petrosal when dealing with petroclival lesions whose consequent anatomical distortion is minimal.KEY WORDS: Petrosal approach. Retrosigmoid approach. Skull base. Petroclival lesion. Neuroendoscopy. manobras cuja análise, entretanto, foge ao desenho deste estudo. CONCLUSÕES Conclusões 67 CONCLUSÕESUtilizando este modelo, os acessos retrossigmoideo e petroso posterior endoscopicamente assistidos não apresentaram diferenças quanto à área de exposição cirúrgica; no entanto, a manobrabilidade total alcançada no acesso retrossigmoideo foi maior que no petroso. O ângulo petroclival e a profundidade clival parecem ter relação com a manobrabilidade, porém não com a exposição cirúrgica, em ambos os acessos. O uso de técnicas assistidas por endoscópio nestes acessos pode dispensar alguns passos cirúrgic...