Examination of the Risk of Normal Perfusion Pressure Breakthrough and Occlusive Hyperemia after Cerebral Arteriovenous Malformation (AVM) Resection Using Intraoperative Cerebral Angiography

Objective: Normal perfusion pressure breakthrough (NPPB) and occlusive hyperemia (OH) have been reported to cause bleeding and cerebral edema after resection of cerebral arteriovenous malformation (AVM). However, much is unknown regarding the mechanism of these events. Additionally, they do not always coincide with the Spetzler–Martin AVM Grading Scale. In this study, we examined the relationship between the changes in intraoperative angiography (IOA) and single photon emission computed tomography (SPECT) findings, and the risk of developing NPPB and OH.Materials and methods: From December 2016 to October 2018 in our hospital, 11 patients underwent AVM resection using intraoperative cerebral angiography (IOA). There were six unruptured AVM cases and five ruptured ones, where the average nidus size was 20.8 mm and the average number of draining veins was 1.9. During surgery, complete resection was confirmed using IOA, and postoperative blood pressure was strictly monitored and controlled. If NPPB or OH was suspected on SPECT the day following the surgery, strict blood pressure management was performed.Results: Unruptured lesions in three cases and ruptured lesions in one case showed significant findings on SPECT. In these cases, stagnation of the contrast agent was observed at the end of the IOA feeders. There were no bleeding complications in patients with suspected NPPB or OH, and cases did not worsen when compared to the preoperative (mRS).Conclusion: Stagnation of the contrast agent at the end of the IOA feeders is effective basis for assessing the risk of NPPB and OH. This is particularly useful for postoperative management, especially for reducing postoperative complications.