January 24, 2016
A highly diffused nature of the AVM nidus as well as the presence of numerous, large, deep, white matter feeders are some of the two most important factors that complicate resection of large Arteriovenous malformations let's review some of these important complicating features and how to manage them intraoperatively. This is a case of a 48 year old female who presented with a history of progressive pulsatile headache. And on imaging was noted to have a large, relatively diffuse, right, enter frontal arteriovenous malformation. This Avion was partially embolized. You can see this Andrew architecture of the malformation primarily fed from the MCA and ACA branches over numerous deep, white matter feeders are present from these vascular territories There are some multiple draining veins involved in this malformation. And again there are two factors that are definitely adding significant risk to the removal of this lesion. Number one is the presence of large, numerous deep white matter feeders. And number two is a very highly diffused nature of the nidus let's go ahead and review the operative events in this case. And right frontal craniotomy was completed in standard fashion. It generous one was performed to provide control over the AVM, and and initial fluorescein angiography demonstrates the location of the deep draining veins. As you can see a large and predominant one here as well as one located here and a one significantly less arterialized moving anteriorly in the nidus of the malformation is localized here. Also based on neuro navigation, the AVM was circumferential disconnected while the predominantly arterialized veins were carefully protected. The more daunting part of the operation is handling the deep, white matter feeders. Some of which were easily amenable to bipolar coagulation. As you can see in this one, however, many of the other ones were very difficult controlled despite the use of clips, another intraoperative fluorescein angiography demonstrates continual Arterialization of the large draining veins. Therefore, a good portion of the AVM still alive at the depth of our resection. Here, you can see some of the deep, white matter feeders that are quite daunting. They own very thin walls and amenable to bipolar coagulation, even clips may not handle them From this soaked cotton was also used to cover some of the bleeding points. Ultimately some brain swelling was encountered in the absence of any obvious hematoma due to heaviness of brain swelling. I decided to stage the operation. All the draining well veins remained intact. I used a piece of gel film to cover the brain. So the second stage can be conducted without any adherence of the dura to the surface of the cortex. Here's the post operative CT scan, which demonstrates lack of a hematoma or significant mass effect. The patient was allowed to recover from this operation and returned to the operating room. About 10 days later, an angiogram was performed between the two stages of the operation, and you can see continual filling of the nidus primarily from the deep, white matter feeders that were quite problematic during the first stage. Here's it later view of a AP as well as lateral angiogram. During the second stage, I removed some of the initial clips to provide additional space. One of the draining veins was occluded temporarily, and then I remained persistent to disconnect the AVM efficiently via a commando operation, because additional bleeding was encountered. However, the brain remained relaxed hemostasis was secured as much as possible via patience. An AVD was placed to achieve some degree of brain relaxation via CSF drainage, intraoperative angiogram, during this stage of the operation revealed no early draining veins. Here's the funnel view of the brand before closure, after your hemostasis was secured, a postoperative CT scan after second stage, and ultimately an angiogram confirmed complete exclusion of the lesion without any early draining veins. Again, this case emphasizes two very important principles and complicating features involved in resection of large AVMs. Number one is presence of numerous, large, deep, white matter feeders. And number two is the diffusivity of the nidus of the AVM. Both factors have to be effectively managed staging of the operation should be highly considered in the presence of branded DEMA. And again, careful management of deep white matter feeders is necessary to avoid complications. Thank you.
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