Name:
10.3171/2022.1.FOCVID21256
Description:
10.3171/2022.1.FOCVID21256
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/ec95f2cf-b331-4e4d-8294-40ddf89fa385/videoscrubberimages/Scrubber_166.jpg
Duration:
T00H10M03S
Embed URL:
https://stream.cadmore.media/player/ec95f2cf-b331-4e4d-8294-40ddf89fa385
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/ec95f2cf-b331-4e4d-8294-40ddf89fa385/21-256.mp4?sv=2019-02-02&sr=c&sig=%2FK04xIZNKmZKzghnJAOCEb7IHMiPa%2B4TFwXwhISXbNk%3D&st=2024-05-19T00%3A56%3A43Z&se=2024-05-19T03%3A01%3A43Z&sp=r
Upload Date:
2022-02-14T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[MUSIC PLAYING]
SPEAKER: In this video, we attempt to highlight surgical nuances in a case of petroclival meningioma operated via modified Dolenc-Kawase anterior petrous rhomboid approach. This was performed as a single-stage surgery, spanning 10 hours. A 48-year-old lady presented to us with previous failed attempt at tumor resection via retromastoid approach. On presentation, she had hoarseness of voice and swallowing difficulty since previous failed surgery.
SPEAKER: On examination, the gag was found to be impaired. There were no other cranial nerve or sensory motor deficits. On preoperative imaging, left petroclival lesion extending from the middle cranial fossa to the posterior cranial fossa was identified. It showed heterogeneous contrast enhancement and was isointense on T2-weighted imaging. It had broad-based attachment to the left petrous ridge, clivus, and tentorium.
SPEAKER: Based on these findings, the likely radiological diagnosis was left petroclival meningioma. DSA showed moderate cross-flow, predominantly across the anterior communicating artery. An anterior petrosectomy approach was chosen in this case, as the tumor was medial to the internal auditory canal, and this approach would provide an early control of the tumor vascularity, and the cranial nerves would be encountered the last.
SPEAKER: Well-preserved hearing of the patient precludes addition of the posterior petrosectomy approach. While the previously failed retromastoid approach was avoided in view of expected adhesions, encountering cranial nerves early in the exposure, and the consequent need to work between the cranial nerves, and the inability to devascularize the tumor early via this approach. Patient was positioned supine with 70 to 80 degrees head turn to the contralateral side, with head in extension, such that the zygomatic arch was at the highest point.
SPEAKER: The table was adjusted in beach- chair fashion with head-end elevation to decrease the intracranial pressure and foot end elevated to increase the venous return. The abdomen was prepared to harvest the fat graft for sealing the dural defect at the end of the surgery. Intraoperative neural monitoring for trigeminal and facial nerves was also utilized. Left-side reverse question mark temporal scalp incision was given.
SPEAKER: Left temporal craniotomy with zygomatic osteotomy was performed. Temporal base was drilled to facilitate optimal access to the lateral wall of the cavernous sinus. Superior orbital fissure was deroofed using high-speed drilling to expose the V1. These are a few images from our cadaveric demonstration to better understand the neural anatomy of the desired region of interest, which shows the relationship between the various structures in the middle cranial fossa.
SPEAKER: Following intradural dissection of the lateral wall of the cavernous sinus. The foramen spinosum was widened, and the middle meningeal artery was coagulated and divided. Intradural dissection of the cavernous sinus is a combination of blunt and sharp dissection. It is initiated in the region of V3 and then continued anteriorly over V2 and V1.
SPEAKER: The basal temporal dura is adherent to the endosteal layer in the region just behind V3. Sharp dissection over the GSPN, the greater superficial petrosal nerve, avoids undue traction to the geniculate ganglion.
SPEAKER: Further dissection of the basal temporal dura from the gasserian ganglion facilitates exposure of the MDK anterior petrous rhomboid. This is cadaveric image collage demonstrating the various triangles of the cavernous sinus and middle cranial fossa exposed during the MDK approach. The MDK anterior petrous rhomboid is bounded anteriorly by the proximal V3 and the gasserian ganglion, laterally by the GSPN, posteriorly by the arcuate eminence, and medially by the petrous ridge.
SPEAKER: High-speed drilling was used to expose the posterior fossa dura by drilling the MDK anterior petrous rhomboid. Drilling was performed parallel to the GSPN, with the inferior extent of drilling until the inferior petrosal sinus and the posterior extent until the internal auditory canal. These cadaveric pictures demonstrate the stepwise dural opening technique and the relationship between various neurovascular structures to the tentorium. Following the drilling, the basal temporal dura is opened in a T-shaped fashion.
SPEAKER: Tentorial sectioning was done in multiple small incisions, carefully preserving the fourth nerve in close proximity to the free margin of the tentorium.
SPEAKER: Superior petrosal sinus was coagulated and ligated to expose the tumor. Tumor debulking is performed using an ultrasonic suction aspirator. It is essential to use this suction aspirator in a paintbrush fashion, and its motion should be parallel to the meningioma fibers.
SPEAKER: Additionally, we've taken anterior tentorial stitch using 5-0 Prolene to retract the anterior tentorial leaflet. This helps to increase the surgical corridor, and allows tumor visualization, and removal from the undersurface of the tentorium. Using fine microdissectors, the trochlear nerve is meticulously separated from the tumor.
SPEAKER: Maintaining the arachnoid plane is of paramount importance in meningioma surgery. Using a combination of sharp, as well as blunt dissection, the tumor is dissected slowly from the brainstem and its perforators. Maintaining the arachnoid plane, the tumor is dissected from the seventh-eighth nerve complex, as well as the sixth cranial nerve.
SPEAKER: This image depicts the fifth, sixth, seventh, and eighth cranial nerve preservation after meticulous tumor dissection. The fifth cranial nerve forms the center of the MDK anterior petrous rhomboid exposure. And the entire tumor, which was superior as well as inferior to the trigeminal nerve, was removed. The basilar trunk in the prepontine cistern was identified.
SPEAKER: The repair of the dural defect is important to prevent CSF leak in the postoperative period. The basal temporal dura is repaired primarily using 5-0 Prolene, and the posterior fossa dural defect is plugged using a combination of fat, fascia, and fibrin glue.
SPEAKER: This is the postoperative noncontrast CT scan of the patient. In the immediate postoperative period, the patient had transient sixth nerve paresis. The lower cranial nerve deficit was the same as in the preoperative period. No other cranial nerve deficit was seen. She had uneventful postoperative recovery. The postoperative contrast-enhanced MRI of the patient at 1-year follow-up shows no evidence of recurrent or residual lesion.
SPEAKER: The MDK anterior petrous rhomboid approach remains a versatile approach for petroclival meningiomas which are not extending lateral or inferior to the internal auditory canal. Pre- and postoperative CT images highlight the operative corridor created by the drilling of the rhomboid. At 3 years' follow-up, the patient is doing well, and the hoarseness of voice and swallowing difficulty have improved postsurgery.
SPEAKER: