Microsurgical resection of ruptured Spetzler-Martin grade III / Lawton-Young grade II parieto-occipital AVMs (a case report)

Occipital arteriovenous malformations (AVMs) cause various visual disturbances and headaches and epileptic seizures. Early diagnosis can lead to treatment that reduces the risk of hemorrhages, visual field loss, and other neurological disorders, as well as the risk of death. Degree III Speczler-Martin arteriovenous malformations (AVMs) are a separate subgroup of brain AVMs. Their diversity in terms of location, type of venous outflow, and size makes them the most heterogeneous group in the AVM classification. The surgical risk of treatment also varies depending on the characteristics of this grade III AVM. In this case, the technical nuances, strategies and principles are described, as well as the steps of surgical resection of a complex right parieto-occipital AVM of the III degree. According to the additional classification, the ruptured aspect and the age of the patient give this lesion a class III. The indications for surgery were the patient's young age, the lifelong risk of recurrent bleeding, and the location of the AVM in the right lateral parieto-occipital region to the closely located Wernicke center and the visual cortex of the brain. The patient was operated on using a posterior parietal-occipital-basal lateral craniotomy. The dura mater attached to the draining vein was left intact during dural exposure. The superficial drainage veins were isolated, the superficial M4 and deep M3 segments of the feeding vessels were found, which were coagulated, and desections were performed in the brain parenchyma and around the AVM glomeruli. The details of AVM resection are described in the text of the article. A complete resection was achieved, and there was no neurological deficit in the postoperative period.