Two Unusual Cases of the Posterior Cranial Fossa Blood Supply

Unilateral Aplasia versus Bilateral Aplasia of the Vertebral Artery: A Review of Associated Abnormalities

“…Unilaterally, CVBA persisted in 19 of cases (10 on the left and 8 on the right side); there was no data about the side of the PPHA in 1 out of 19 cases [ 33 ]. A persistence of CVBA was as follows: (1) PIA persisted 17 times—8 bilaterally, 5 on the left side, and 4 on the right side [ 14 , 15 , 17 , 19 , 20 , 22 – 25 , 28 , 30 – 32 , 34 – 37 ]; (2) PHA persisted 10 times—1 bilaterally, 5 on the left side, 3 on the right side, and 1 without data [ 16 , 21 , 26 , 29 , 33 , 38 – 42 ]; (3) PTA persisted 3 times—1 bilaterally, 1 on the left side (associated with bilateral PPIAs), and 1 on the right side [ 19 , 27 , 43 ].…”

“…Otherwise, associated aplasia of other vessels was related to the PCoA that was found bilaterally in 3/31 cases [ 20 , 33 , 41 ] and unilaterally in 1 out of 31 cases [ 23 ], as well as to the BA also in one case [ 43 ], and to some dural sinuses simultaneously with bilateral internal jugular veins in another case [ 30 ].…”

“…So, the BA as a continuation of the left OA [ 44 ], the OA as a branch of the PPIA [ 25 ], or the posterior inferior cerebellar artery (PICA) as BA branch [ 21 , 25 ] or PPHA branch [ 33 ] was described. Fetal origin of the PCA [ 23 , 43 ] and anastomoses with thyrocervical and/or OA branches [ 22 , 27 ] in two particular cases were found. Enlargement of some dural sinuses and Galen's vein malformation [ 30 ], hypoplasia of bilateral posterior communicating arteries [ 42 ], irregular caliber of ICA [ 14 ], or tortuous course of the PPHA [ 41 ] was found in single cases.…”

“…Vascular pathology was noted in 16/31 cases. Aneurysms of different arteries, BA [ 16 , 42 ], anterior communicating artery [ 16 , 17 , 33 ], ICA [ 43 ], PPHA [ 41 ], as well as stenosis of carotid arteries [ 20 , 23 , 27 , 31 – 33 , 35 , 38 , 42 ], or cerebral infarction [ 18 , 25 , 27 ] among them, angiographically were confirmed.…”

Association of two primitive carotid-basilar anastomoses and cerebrovascular abnormalities on the brain base: a case report

“…It was discovered in human fetuses (4), neonates and infants (9), in the fourth decade (3,22), or in the elderly-eighth (13,23) and ninth decade of life (19). The PPTA persisted singly and unilaterally (3,4,6,7,9,11,13,15,22,23), or Simultaneous presence of the persistent primitive trigeminal artery and so-called intermediate communicating artery was discovered in a 77-year-old cadaver autopsied due to the myocardial infarction. Many vascular variants and abnormalities such as aplasia of the right vertebral artery (VA), presence of two right posterior cerebral arteries (PCAs), partial duplication of the right superior cerebellar artery, hypoplasia of the pre-communicating part (A1) of the right anterior cerebral artery and the right PCA of basilar origin, a special configuration of the anterior communicating artery (ACoA), and a small aneurysm at the right A1-ACoA junction were associated.…”