[Operation for infratentorial arteriovenous malformations].
Concerning infratentorial AVMs in three representative localizations, their surgical approaches, technical standards and technical difficulties were described and discussed. At the beginning, our opinion emphasized that feeding arteries should be divided into parent feeders and proper feeders. Parent arteries are anatomically normal ones even if dilated by the presence of peripheral shunt. Proper feeders, however, supply only AVMs without perfusing any normal brain tissue. Draining veins were also divided into two, parent drainers and proper drainers. Vascular connections should be separated at proper feeders and proper drainers in case of surgical removal of AVM. Three characteristics were summarized as follows: 1) Tonsillar AVM does not offer any problem to its surgical approach. Technical standard for removal of AVM is described here. Principal parent feeder in this lesion is PICA and parent drainer is inferior vermain vein. 2) AVM in the cerebellopontine angle has three major problems in surgery. i) Main feeder is AICA. Differentiation between parent feeder and proper feeder is sometimes difficult because of its long and complicated course. ii) A part of AVM often clings to the cranial nerves (VII, VIII). iii) A part of AVM occasionally intrudes into the side wall of the pons. The latter two problems could be solved by leaving a part of AVM after isolation from blood flow. 3) AVM is the upper vermis offers a lot of debates. Its surgery is the most controversial one. Three surgical approaches are proposed and discussed. i) Subtemporal transtentorial approach. ii)Suboccipital transtentorial approach. iii) Infratentorial supracerebellar approach.
D002531:Cerebellum / Q000098:blood supply; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000601:surgery*; D008722:Methods; D011149:Pons / Q000098:blood supply