To investigate the proliferation and apoptosis of vascular tissue in different time periods after partial embolization of brain arteriovenous malformation (BAVM).

A total of 32 BAVM specimens resected at the Department of Neurosurgery, Henan Provincial People's Hospital, from January 2018 to January 2021, including 24 preoperative embolization + surgical resection specimens, which were divided into short-term group (interval < 1 day), medium-term group (1 day < interval < 28 days), long-term group (interval > 28 days) according to the time interval between preoperative embolization and surgical resection.The control group consisted of 8 patients with BAVM specimens that were surgically removed alone. H E staining was used to observe the differences in the gross pathology of BAVM among different groups, immunohistochemical detection of VEGF, eNOS as well as caspase-3 was used to determine the proliferation and apoptotic activity of BAVM vascular tissues, immunofluorescence detection of CD31 was used to assess the number of neovessels, and TUNEL staining was used to detect the number of apoptosis in BAVM vascular tissues.

The expressions of VEGF, eNOS, and Caspase-3 in BAVM was higher in the medium-term group compared with all other groups (P < 0.05); There were also significant differences in the number of neovessels and apoptotic cells of BAVM in the medium-term group compared with the other groups (P < 0.05).

Preoperative embolization can cause proliferation and apoptosis of BAVM vascular tissue, and such proliferation and apoptosis phenomenon was closely related to the embolization time, which was most obvious at the middle stage (1 day-28 days) of embolization.So a long interval between embolization and surgery may increase the risk of bleeding for the patients.