Name:
Management of jugular bulb injury during retrosigmoid transmeatal resection of vestibular schwannoma
Description:
Management of jugular bulb injury during retrosigmoid transmeatal resection of vestibular schwannoma
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Duration:
T00H06M25S
Embed URL:
https://stream.cadmore.media/player/41862422-0f94-4fe6-a05a-692e1b710064
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/41862422-0f94-4fe6-a05a-692e1b710064/21-55.mp4?sv=2019-02-02&sr=c&sig=a8%2BgAqYXRh25f9i6zkpY%2BfGB%2BW6wlCfSFEqrdQfeeiI%3D&st=2024-05-02T22%3A34%3A26Z&se=2024-05-03T00%3A39%3A26Z&sp=r
Upload Date:
2021-10-27T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[MUSIC PLAYING]
SPEAKER: In this video, we demonstrate the management of jugular bulb injury during restrosigmoid transmeatal resection of vestibular schwannoma. The patient was a 51-year-old woman, with a history of right-sided deafness, first noticed 3 years prior to consult. Audiogram confirmed nonserviceable hearing on the right side. An MRI showed a cerebellopontine angle mass compatible with a Hannover T4a vestibular schwannoma, extending to the most lateral part of the internal auditory canal.
SPEAKER: Bilateral high- riding jugular bulbs were also noted, reaching up to the inferior limit of the internal auditory canal with the right side being dominant. However, it did not appear as it would be exposed during drilling of the internal auditory canal. We performed a right restrosigmoid craniotomy in dorsal decubitus in standard fashion. After opening the lateral cerebellomedulary cistern and exposing the tumor, we raised the anterior flap to expose the posterior wall of the internal auditory canal, before beginning tumor resection.
SPEAKER: Drilling began using a large cutting drill bit to outline the internal auditory canal, then using smaller bits in the lateral portion. At approximately 8 mm from the internal auditory meatus, brisk bleeding was encountered from the jugular bulb, while using a large diamond bit. The head was immediately lowered at the level of the heart, and we let blood to fill the surgical side, not suctioned directly over the jugular bulb to prevent air embolism.
SPEAKER: A small cotton pledget was placed over the defect to aspirate the pool blood safely. Then a small crushed muscle patch was used to seal the defect, carefully positioning it below the cotton pledget. This graft is also obtained during the approach to reconstruct the internal auditory canal after resection of the tumor, which is why we prefer it over all the synthetic materials such as bone wax or gelatin sponge.
SPEAKER: When positioning the graft, extreme care must be taken to avoid occluding the jugular bulb. So that patch must be gently placed to cover the laceration of the bulb without tamponading the lumen, nor entering the bulb and potentially becoming embolic material. It may take a while to obtain adequate closure and still allow proper visualization to continue the surgery.
SPEAKER: After bleeding stopped, fibrin glue was applied to seal the defect. Using cutting and coarse diamond drill bits of decreasing size, drilling was continued with care to avoid cutting the muscle with the drill. Since visualization to the most lateral anterior part of the internal auditory canal was still partially limited by the graft, we needed to expand the opening of the superior wall to come out and improve the angle of attack.
SPEAKER: Here, we also needed to trim the muscle graft to improve visualization. Then, we continued gradually drilling around the muscle patch from medial to lateral and from superior to inferior, palpating with a blunt dissector the limits of the canal until we achieved sufficient exposition, which meant opening around 100 degrees of it, far more than is usually needed. The dura of the internal auditory canal was incised parallel to the path of the nerves.
SPEAKER: The internal debulking began at a level of the meatus. Using blunt and sharp dissection, the tumor was gradually reduced and separated from the brainstem following the arachnoid plane. Inside the internal auditory canal, the tumor was gently dissected from the nerves. In this case, the superior vestibular nerve was first identified and cut. At this point it was noted that residual tumor remained in the most lateral part of the inferior vestibular nerve, which was the nerve of origin.
SPEAKER: So additional drilling was needed to expose the remaining lesion. By carefully drilling below the patch, the tumor was removed completely from the internal auditory canal. Lastly, the cisternal portion of the tumor was resected, first identifying the cochlear nerve in the entering field quadrants of the tumor and the facial nerve in the medial part of it.
SPEAKER: By gently dissecting the tumor from the facial nerve, gross-total resection was achieved. The facial nerve could be preserved both anatomically and functionally, whereas the cochlear nerve had to be sacrificed. Finally, the internal auditory canal was reconstructed with a large muscle patch and fibrin. Postoperatively, the patient developed House-Brackmann grade 3 facial palsy and moderate headache that spontaneously resolved on post op day five.
SPEAKER: MRI confirmed gross-total resection of the lesion, as well as a small thrombus on the dome of the jugular bulb, without occlusion of venous blood flow. We do not routinely anticoagulate such cases. In conclusion, a high- riding jugular bulb must be actively looked on preoperative images, as it might be presenting around 9% of patients undergoing surgery for vestibular schwannoma. In case of laceration during the transmeatal stage of resection, all actions should be focused on preventing air embolism.
SPEAKER: The defect might be effectively closed with a crushed muscle patch, and extreme care must be taken to position the graft without occluding blood flow. It is also prudent to evaluate stopping surgery in case complete occlusion is suspected, particularly in dominant bulbs. A severe cerebellar edema may rapidly set in and further complicate resection. In nondominant bulbs, occlusion may produce engorgement of cerebellar veins or an increase in cerebellar venous bleeding.
SPEAKER: Finally, anticoagulation is not usually indicated, and few reports have shown safety in close monitoring of these cases.