The anatomic analysis of the vidian canal and the surrounding structures concerning vidian neurectomy using computed tomography scans / Avaliação anatômica do canal vidiano e estruturas adjacentes por tomografia computadorizada para a neurectomia do vidiano

Abstract Introduction: The type of endoscopic approach chosen for vidian neurectomy can be specified by evaluating the vidian canal and the surrounding sphenoid sinus structures. Objective: The variations and morphometry of the vidian canal were investigated, focusing on the functional correlations between them which are crucial anatomical landmarks for preoperative planning. Methods: This study was performed using paranasal multidetector computed tomography images that were obtained with a section thickening of 0.625 mm of 250 adults. Results: The distributions of 500 vidian canal variants were categorized as follows; Type 1, within the sphenoid corpus (55.6%); Type 2, partially protruding into the sphenoid sinus (34.8%); Type 3, within the sphenoid sinus (9.6%). The pneumatization of the pterygoid process is mostly seen in vidian canal Type 2 (72.4%) and Type 3 (95.8%) (p < 0.001). The mean distances from the vidian canal to the foramen rotundum and the palatovaginal canal were greater in the vidian canal Type 2 and 3 with the pterygoid process pneumatization (p < 0.001). The prevalence of the intrasphenoid septum between the vidian canal and the vomerine crest and lateral attachment which ending on carotid prominence were much higher in vidian canal Type 3 than other types (p < 0.001). The mean angle between the posterior end of the middle turbinate and the lateral margin of the anterior opening of the vidian canal was measured as 33.05 ± 7.71°. Conclusions: Preoperative radiologic analysis of the vidian canal and the surrounding structures will allow surgeons to choose an appropriate endoscopic approach to ensure predictable postoperative outcomes.

Resumo Introdução: O tipo de abordagem endoscópica para a neurectomia do vidiano pode ser definido pela avaliação do canal do vidiano e das estruturas adjacentes aos seios esfenoidais. Objetivo: Investigar as variações e a morfometria do canal vidiano com enfoque nas suas correlações funcionais, pois são parâmetros anatômicos cruciais para o planejamento pré-operatório. Método: Esse estudo foi realizado utilizando-se imagens de tomografia computadorizada multidetectores dos seios paranasais com espessura de corte de 0,625 mm obtidas de 250 indivíduos adultos. Resultados: A distribuição das 500 variantes do canal vidiano foi categorizada da seguinte forma: Tipo 1, dentro do corpo ósseo esfenoidal (55,6%); Tipo 2, protrusão parcial no interior do seio esfenoidal (34,8%); Tipo 3, no interior do seio esfenoidal (9,6%). A pneumatização do processo pterigoide foi observada principalmente no canal vidiano Tipo 2 (72,4%) e Tipo 3 (95,8%) (p < 0,001). As distâncias médias do canal vidiano até o forame redondo e o canal palatovaginal foram maiores no canal vidiano do Tipo 2 e 3, com a pneumatização do processo pterigoide (p < 0,001). A presença do septo intraesfenoidal entre o canal vidiano e a crista vomeriana e a extensão lateral, que termina na proeminência da carótida, foi muito maior no canal vidiano Tipo 3 do que nos outros tipos (p < 0,001). A angulação média entre a cauda da concha média e a margem lateral da abertura anterior do canal vidiano foi de 33,05° ± 7,71°. Conclusões: A análise radiológica pré-operatória do canal do vidiano e das estruturas circunjacentes permitem ao cirurgião escolher uma abordagem endoscópica apropriada e prever resultados pós-operatórios.

Endoscopic endonasal approach for mass resection of the pterygopalatine fossa

OBJECTIVES: Access to the pterygopalatine fossa is very difficult due to its complex anatomy. Therefore, an open approach is traditionally used, but morbidity is unavoidable. To overcome this problem, an endoscopic endonasal approach was developed as a minimally invasive procedure. The surgical aim of the present study was to evaluate the utility of the endoscopic endonasal approach for the management of both benign and malignant tumors of the pterygopalatine fossa. METHOD: We report our experience with the endoscopic endonasal approach for the management of both benign and malignant tumors and summarize recent recommendations. A total of 13 patients underwent surgery via the endoscopic endonasal approach for pterygopalatine fossa masses from 2014 to 2016. This case group consisted of 12 benign tumors (10 juvenile nasopharyngeal angiofibromas and two schwannomas) and one malignant tumor. RESULTS: No recurrent tumor developed during the follow-up period. One residual tumor (juvenile nasopharyngeal angiofibroma) that remained in the cavernous sinus was stable. There were no significant complications. Typical sequelae included hypesthesia of the maxillary nerve, trismus, and dry eye syndrome. CONCLUSION: The low frequency of complications together with the high efficacy of resection support the use of the endoscopic endonasal approach as a feasible, safe, and beneficial technique for the management of masses in the pterygopalatine fossa.