More Videos

Lateral Parietal AVM

July 29, 2016


Here's another case of a Lateral Parietal Arteriovenous Malformation. This is a 62 year old female who presented with Spontaneous Inter Cerebral Hemorrhage. CT scan demonstrated the location of the hemorrhage, and the presence of the arteriovenous malformation just lateral and slightly anterior to the location of the hematoma. Preoperative angiogram demonstrated a very dominant distal MCA branch feeding the malformation with at least two draining veins, moving more superiorly and posteriorly. I do not believe embolization is usually necessary, unless the feeding vessels are not readily accessible during the early phases of the operations, such as a large tentorial arteriovenous malformation, where the superior cerebellar artery feeders can be quite inaccessible. Again, at the earlier stages of the operation. This patient underwent resection as you can see in the lateral position, relatively large skull flap was elevated. Following completion of the craniotomy, the dura was opened based over this presacral sinus. As you can see, especially in the presence of hemorrhage it may be at times difficult to clearly identify or differentiate the identity of a vein versus a large arterial feeder leading to the malformation. In this case, this is anterior, posterior, and this is toward the feeder of the patient or leading in the caudal direction. Initially, the questionably vein or more likely the large MCA branch that was leading to the malformation was skeletonized toward the malformation. Subsequently, the peel phase of the section, continued to circumferentially disconnect the malformation. The hematoma is expected to be just medial to the malformation. In this case, based on the preoperative CT angiogram to better evaluate the identity of the vessels in terms of being arterial versus venous an ICG fluorescent angiogram was completed and a FLOW 800 map was prepared. Here you can see that, this vessel is unquestionably the large distal MCA feeding vessel as expected based on preoperative angiogram. The rest of the vessels that are located just superior to the AVM are draining veins. Again, the redder vessels are earlier in the ICG phase of the angiogram and therefore arterial, the orange and blue vessels are vessels in the later stages of the ICG angiogram. And therefore are venus. You can see that the arterial veins are appearing orange versus blue which is the color of their normal venous structures. So I continued circumferential disconnection of the malformation. Again, this draining vein was carefully protected. The arterial feeder was disconnected. I think the FLOW 800 map allowed me to definitively identified the feeding vessels and draining veins. As the malformation is mobilized. The hematoma cavity is encountered. The blood clot is evacuated. And again, circumferential of disconnection of the malformation continues while preserving the more superiorly located draining vein. Here is mobilization of the malformation out of the hematoma cavity, further dissection in order to skeletonize the draining veins. There's plenty of hematoma within the cavity that should be evacuated after the Natus is extracted. There is no deep feeder vessels since the hematoma has essentially completed the more difficult plane of dissection. Additional pieces of the hematoma are removed in order to achieve more brain relaxation. Here's only one final collection of the malformation to the draining vein. Further inspection reveals no other hidden large arterial feeding vessels. Here you can see the draining vain at the tip of my arrow. It's temporary, occlusion reveals encephalitis swelling Therefore the draining vein was also coagulated and cut, and the Natus was removed. It's important to spend additional time making sure the hematoma is aggressively removed as aggressive removal of the clot can potentially facilitate early recovery of the patient. Ampulla minor blood clot is present underneath edges of the corticotomy. I continue to deliver the blood clots, piece by piece. Immaculate hemostasis is secured. Postoperative ICG angiogram, reveals no early draining veins. This finding is further confirmed using the FLOW 800 map, which reveals small feeding arteries to the normal cortex without any early draining veins. And a postoperative angiogram confirmed complete exclusion of the malformation without any AV shunting and the postoperative CT also confirmed complete removal of the blood clot and this patient made an excellent recovery. And actually her hemiparesis disappeared completely within one month after her surgery. Thank you.

Please login to post a comment.

You can make a difference: donate now. The Neurosurgical Atlas depends almost entirely on your donations: donate now.