Microanatomical bases for intraoperative division of the posterior communicating artery

Micro-anatomical parameters of the hypoplastic posterior communicating artery (PCoA) are assessed and compared with the micro-anatomical parameters of the adult type PCoA. Based on the results obtained, the safest place is proposed for PCoA division during basilar tip aneurysm surgery via the pterional route.

In 35 human cadaver brains, red coloured latex was injected and micro-anatomical dissection was performed.

Seventy PCoA were found. Adult type PCoA was found in 29 cases (41.43%) with mean length 12.58 mm. Reduction of the PCoA diameter from its anterior to its posterior third by up to 20% was found in 27% and by more than 20% in 10% of the cases. The mean perforating vessel number was 8.17, distributed in each third: 3.48, 2.90 and 1.79, respectively. A hypoplastic PCoA was found in 33 cases (47.14%) with mean length 16.09 mm. The PCoA's diameter reduction by up to 20% was found in 24% and by more in 27% of the cases. In 6% of the cases an extreme reduction by up to 70% was observed. The mean perforating vessel (PV) number was 8.82, distributed in each third: 3.18, 3.36 and 2.27, respectively.

Hypoplastic PCoA tends to be longer and with a more distinct diameter reduction from the anterior to the posterior third than the adult type PCoA. The PV anatomical parameters are similar for both groups. The posterior third of the PCoA seems to be the area where the risk of perforating vessel damage is the least when performing intra-operative PCoA division.