Type A fistulas diagnosed angiographically are direct connections between the internal carotid artery (ICA) and cavernous sinus, and type B fistulas are between meningeal branches
of the ICA and cavernous sinus.
Selective injection of both ECAs demonstrated normal appearing frontal and parietal meningeal branches
without dural supply to the posterior frontal mass.
The sigmoid sinus, inferior petrosal sinus, meningeal branches
of occipital and ascending pharyngeal arteries, glossopharyngeal nerve, vagus nerve and accessory nerve with their ganglia traverse the foramen.
[1,3] Posterior condylar canal also transmits meningeal branches
of the occipital artery.
Gabriele and Bell (1967) stated that if meningiomas are supplied by meningeal branches
that anastamose with the lacrimal artery branches there may be striking and clinically important enlargement of the ophthalmic artery and its branches.
In direct fistula, there is a shunt between the internal carotid artery and the cavernous sinus, whereas in indirect fistula, the intracavernous portion of the internal carotid artery remains intact and arterial blood flows through the meningeal branches
of the carotid artery into the cavernous sinus.
The anatomy of lumbosacral posterior rami and meningeal branches
of spinal nerves (sinu-vertebral nerves).
Multiple dural feeders from meningeal branches
of occipital and superficial temporal branches of bilateral external carotid and right internal carotid arteries.