VARIABLE ANATOMY OF THE INFRATROCHLEAR AND SUPRATROCHLEAR TRIANGLES AND THEIR MICRONEUROSURGICAL IMPORTANCE

Abstract

Objective: Supratrochlear and infratrochlear triangles are surgical corridors for approaching the lateral wall of the cavernous sinus. The literature provides conflicting results for the morphology and morphometry of these triangles. Additionally, the possible effects of vascular structures that drain into the cavernous sinus in unknown. This study aimed to investigate the morphology, morphometry, and vascular relationships of the supratrochlear and infratrochlear triangles of the cavernous sinus. Material and Method: Cranial bases of 25 cadavers were dissected bilaterally under a surgical microscope. Five of the cadavers were injected with colored silicone for vascular evaluation. The morphology of supratrochlear and infratrochlear triangles were classified according to the course of the trochlear nerve. Photogrametric measurements were used for evaluating the areas of both triangles with the ImageJ software. The triangular morphology was also investigated in regard to the drainage patterns of the superficial middle cerebral vein and cranial base dural sinuses. Results: Type A, B, C, and D triangle morphology was present on 23 (46%), 9 (18%), 10 (20%), and 8 (16%) sides, respectively. The average areas for supratrochlear and infratrochlear triangles were 22.2 (±11.7) mm2 and 78.4 (±27.7) mm2, respectively. The supratrochlear triangle was significantly larger in Type D triangles. On 71.4% of injected specimens, the superior petrosal sinus contributed the cavernous sinus and formed a Type A triangle. Conclusion: The anatomy of the supratrochlear and infratrochlear triangles are highly variable than previously reported. Introducing the knowledge regarding these variations to neurosurgical residency education programs and daily surgical practice could be valuable.

Keywords

• Cavernous sinus
• supratrochlear triangle
• infratrochlear triangle

Project Number

TSA-2016-20144

İNFRATROKLEAR VE SUPRATROKLEAR ÜÇGENLERİN VARYATİF ANATOMİSİ VE MİKRONÖROCERRAHİ ÖNEMİ

Abstract

Amaç: Supratroklear ve infratroklear üçgenler, sinus cavernosus’un lateral duvarına ulaşmak için kullanılabilecek cerrahi koridorlardır. Literatürde bu üçgenlerin morfolojisi ve morfometrisi hakkında çelişkili bilgiler bulunmaktadır. Ayrıca, sinus cavernosus’a drene olan vasküler yapıların anatomiye olan etkileri bilinmemektedir. Bu çalışma sinus cavernosus üçgenlerinde olan supratroklear ve infratroklear üçgenlerin morfolojisini, morfometrisini ve vasküler komşuluklarını incelemeyi amaçlamıştır. Gereç ve Yöntem: Yirmibeş kadavranın kafa tabanı cerrahi mikroskop altında bilateral olarak disseke edildi. Vasküler yapıların değerlendirilmesi amacıyla 5 kadavrada renkli silikon enjeksiyonu yapıldı. Supratroklear ve infratroklear üçgen morfolojisi, n. trochlearis’in uzanımına göre sınıflandırıldı. Her iki üçgenin alanları, ImageJ yazılımı kullanılarak fotogrametrik yöntem ile ölçüldü. Üçgenlerin morfolojisi ile v. cerebri media superficialis ve kafa tabanı dural sinüslerinin drenaj paterni karşılaştırıldı. Bulgular: Tip A, B, C ve D üçgen morfolojisi sırasıyla 23 (%46), 9 (%18), 10 (%20) ve 8 (%16) tarafta gözlemlendi. Supratroklear ve infratroklear üçgenlerin ortalama alanları 22,2 (±11,7) mm2 ve 78,4 (±27,7) mm2 ölçüldü. Tip D üçgenlerde supratroklear üçgenin daha büyük olduğu görüldü. İnjeksiyon yapılan örneklerin %71,4’ünde sinus petrosus superior, sinus cavernosus’a drene olmakta ve belirgin Tip A üçgen meydana getirmekteydi. Sonuç: Supratroklear ve infratroklear üçgenler, literatürde raporlandığının aksine çok varyatifti. Bu çeşitlilik bilgisinin beyin cerrahisi uzmanlık eğitimi ve günlük cerrahi uygulamaya aktarılması düşünülebilir.

Keywords

• Sinus cavernosus
• supratroklear üçgen
• infratroklear üçgen

Supporting Institution

İstanbul Üniversitesi Bilimsel Araştırma Projeleri Koordinasyon Birimi

Project Number

TSA-2016-20144

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