Encasing the Vertebral Arteries – A Foramen Magnum Challenge (Farlateral approach)

Added: 2026-05-07

[00:00:00]A 58-year-old female patient presented to the OPD with difficulty in chewing and sometimes biting her own tongue.

[00:00:07]And she has change in voice and difficulty in deglutition. With these complaints, she was evaluated with MRI brain plain and contrast, which revealed a giant foramen magnum meningioma that is encroaching on both vertebral arteries.

[00:00:21]Later, she was planned for surgery in a the approach was far lateral approach with mobilization of the vertebral artery and drilling of the condyle. She was placed in park bench position.

[00:00:33]And the incision was taken retroauricularly extending from occipital region to the neck. And the surgery was started with raising the skin flap followed by uh raising the muscular plane and uh we have started first with the mobilization of the vertebral artery.

[00:00:54]The C1 arch is identified and the lateral part of the C1 arch where the foramen uh where the vertebral artery enters the uh foramen for vertebral artery has been identified. And first initially uh the vertebral artery below the foramen has been skeletonized. That the vertebral artery is followed and we have deroofed the uh vertebral artery foramen over the C1 uh C1 uh posterior arch and the vertebral artery is completely mobilized.

[00:01:27]And the vertebral artery is followed in where it enters the dura where it enters the dura and into the brain.

[00:01:38]The mobilization of the vertebral artery has to be done very carefully without injuring uh the vertebral artery as it may lead to vasospasm of the vertebral artery.

[00:01:49]Slowly, the adhesions are cut over the over the artery without causing any injury to the vessel.

[00:01:58]The adhesions are coagulated away from the artery without causing any heat injury to the vessel.

[00:02:10]With sharp dissection, all the adhesions are slowly cleared off.

[00:02:14]And the complete uh skeletonizing of the vertebral artery is achieved. Once the skeletal artery uh is skeletonized and its entry into the dura has been marked and we slowly stop uh we slowly start for the next step, that is drilling of the bone.

[00:02:43]The bone is started drilling we started drilling the bone in the suboccipital region exposing the dura and we encountered several uh emissary veins on the wall over the bone we which are uh stopped with uh the bleeding has been stopped with uh adequate bone wax application. Later the condyle is identified and it is started we started drilling the condyle.

[00:03:11]Once the condyle drilling is being done, you can see many uh vessels that are there there is a good amount of bleeding from the condyle. So uh adequate hemostasis with application of bone wax is necessary. Once the condyle has been drilled and the adequate exposure of the dura has been done, the vertebral artery is uh you can see the vertebral artery pulsating which is covered with a cotton uh cotton patty and the dura is opened in the suboccipital region. Once the dura is opened we identify uh the we identify the cisterna magna and we drain the cisterna magna. Once the cisterna magna is drained there is adequate space for operating and uh the CSF has been let out. Once the CSF has been let out uh the tension has been reduced and we can see the brain pulsating. Here we can see the tumor.

[00:04:11]Uh first appearance of the tumor can be seen here which is very close to the brainstem. So adequate uh necessary steps are to be have be to be taken not to apply too much pressure on the brain.

[00:04:26]Uh here we simultaneously use uh neuro monitoring to identify the nerves.

[00:04:32]Uh once the tumor has been identified, the surface is coagulated and the tumor is slowly started uh peeling it away from the brainstem. And we could get a good plane between the tumor and uh the brainstem.

[00:04:47]Uh once the arachnoid has been peeled up, we can identify the 12th nerve here which is very close to the tumor and some part of it is being encroached into the tumor encroached by the tumor.

[00:04:59]Under nerve monitoring, we have identified the trapezius uh nerve supplying to the trapezius that is spinal accessory nerve and the 12th nerve has been identified with neuro monitoring. Once they are identified, they are pushed away from the tumor onto the brain and we are doing a dissection between the tumor and the dural surface and the surface of the tumor between the dura and the tumor.

[00:05:24]Uh we also take care not to apply any pressure over the brainstem. So all the pressure and all the work has to be done between the tumor and the dura. Here we can see the vertebral artery uh first glimpse of the vertebral artery that is uh that has been encroached by the tumor. That is this is on the right side.

[00:05:43]>> [snorts] >> Once the tumor uh once the vertebral artery is identified, we slowly uh start debulking the tumor. As the tumor is very calcific and fibrous the uh user and the predator could not be kept here and removed. So we we slowly started removing the piece by piece bit by bit. Here you can see the 12th nerve and the vertebral first glimpse of the vertebral artery can be seen here.

[00:06:09]The 12th nerve is slowly dissected off the tumor and it is pushed away from the tumor. Uh that is the vertebral artery that is within the tumor.

[00:06:20]So we started coagulating the tumor bit by bit and here again we are using the nerve monitoring to check for the 12th nerve.

[00:06:29]The 12th nerve is slightly adherent to the tumor which is coagulated and cut.

[00:06:34]The tumor has been coagulated and cut and 12th nerve is released away from the tumor.

[00:06:40]Once this is done we can have a ample amount of space to operate onto the tumor. See the vertebral artery can be seen uh being reflected away from the tumor here. That is a free part of the vertebral artery.

[00:06:54]And once that is done, we have good access to the tumor. Now the main part of the process will be debulking of the tumor. As the tumor is very fibrous and it is very difficult to remove and we have started removing it bit by bit and the cautery has been kept at its low at the lowest and we are coagulating the tumor slowly.

[00:07:17]The tumor is being removed by in a piecemeal fashion with with the use of dissector and uh tumor holding forceps without damaging any of the neural structures or the arterial structures.

[00:07:32]The entire tumor is slowly removed uh in a piecemeal fashion.

[00:07:39]This is the zoom in for focus of the tumor. We can see the blood oozing out from the tumor surface and this has to be controlled with adequate uh hemostasis that is between the tumor and the dural surface. Once the dural surface has been coagulated, uh we could get uh good hemostatic uh hemostasis and the field will be very clear. Here we are now moving into the base of the tumor and slowly removing the tumor bit by bit.

[00:08:11]Now we are about to enter to the opposite side of the tumor and uh we are using a disc punch to remove the tumor bits that are very adherent to the dura.

[00:08:22]Now we we could get a first glimpse of the vertebral artery on the opposite side.

[00:08:30]Once this chunk of tumor has been decored we will be encountering the vertebral artery on the opposite side.

[00:09:27]As the tumor is very calcific and very very adherent to the dural surface we have partially removed the tumor and the rest of the tumor bed and the tumor is being coagulated.

[00:09:41]Using a dissector, the plane is being created between the tumor tumor bed and the dura.

[00:09:47]And with every step, there is some amount of blood oozing which is controlled with the bipolar.

[00:09:55]Now we can see most of the tumor has been removed and we are onto the surface of the dura where there is very big adherent tumor that is being coagulated for hemostasis.

[00:10:06]Once we confirm adequate hemostasis now we start closure of the we will start closing the dura in a watertight fashion.

[00:10:16]Once this is completed, a drain has been kept and the bone and skin flap has been closed.

[00:10:25]Postop MRI has been done which revealed good decompression of the tumor with slight amount of tumor that is left adherent to the dura which is very calcific. The rest of the brain has decompressed well.