An anatomical study of the pathophysiology of carotid cavernous sinus fistula associated with Le Fort III osteotomy.

Unlabelled: Carotid-cavernous sinus fistula (CCF) is a rare complication occurring after the Le Fort osteotomy. We aimed to elucidate the cause of CCF in the Le Fort osteotomy.

Methods: Eleven fresh cadavers were used. After craniotomy, a Le Fort III bipartition osteotomy was then performed. On the left side, both the lateral wall of the maxilla and the pterygomaxillary junction (PMJ) were divided, in addition to the conventional osteotomy line. On the right side, those parts were kept intact. After the osteotomy, a tensiometer was fixed to the skull base. The sensor was linked with the wall of the carotid artery in the cavernous portion. A down-fracture was then performed initially from the left, followed by the right. Tensile force data of both sides were recorded.

Results: In all cases, a higher tensile load was observed on the right side compared to the left side. In right side, two skull base fractures complexed with high pterygoid process fractures, and nine pure high fractures of the pterygoid process were identified.

Conclusions: During down-fracture, the wall of the carotid artery experiences significant tensile load. The tensile load on the arterial wall may collapse the fine branches of the carotid artery in the cavernous portion.