Name:
10.3171/2022.3.FOCVID2220
Description:
10.3171/2022.3.FOCVID2220
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/0e162a4c-28f8-4bdc-817e-f25b9256729a/videoscrubberimages/Scrubber_218.jpg
Duration:
T00H05M32S
Embed URL:
https://stream.cadmore.media/player/0e162a4c-28f8-4bdc-817e-f25b9256729a
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/0e162a4c-28f8-4bdc-817e-f25b9256729a/10. 22-20.mp4?sv=2019-02-02&sr=c&sig=atfo2F06Wx7VOPsYH231bFO8iJrrk7GyaFooJHoIYCs%3D&st=2024-05-01T14%3A09%3A13Z&se=2024-05-01T16%3A14%3A13Z&sp=r
Upload Date:
2022-06-01T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[MUSIC PLAYING]
SPEAKER: MIS lateral retroperitoneal transpsoas approach allows gross- total resection of a giant L4 schwannoma. This is a 60-year-old man referred to my clinic for intermittent tingling and paresthesias involving the dorsum of the right foot, which had significantly worsened over the past 6 months and were affecting his sleep and quality of life. MRI of the lumbar spine showed a contrast- enhancing lesion in the psoas adjacent to the right neuroforamen at L4-5, with remodeling of the foramen, the L4 vertebral body, and L5 superior articular process.
SPEAKER: Imaging characteristics and clinical presentation were consistent with benign nerve sheath tumor. We discussed treatment options with the patient, including conservative management with imaging follow-up, but due to the progressive symptomatology and tumor size, as well as the need for a definitive diagnosis, I favored surgical removal. After discussing the potential surgical approaches, including posterior approach with fasetectomy and fusion, posterior paraspinal approach, or direct lateral minimally invasive retroperitoneal transpsoas approach, the patient decided for the lateral approach, which was also my preference.
SPEAKER: The patient was taken to the operating room and positioned in the lateral decubitus position. Continuous free-running EMG, direct stimulation EMG, and motor evoked potentials were obtained and remained at baseline throughout the procedure. Fluoroscopy was used to localize the level of the L4 pedicle, as well as the anterior and posterior vertebral body line to plan our incision. Meticulous positioning as well as clear orthogonal AP and lateral x-ray views are paramount for this approach to maintain safe working angles to the psoas.
SPEAKER: After skin incision, the muscular fascia is identified and sharply incised. Blunt dissection of the external oblique, internal oblique, and transverse abdominal muscle is performed and the transversus fascia is identified. This is opened bluntly to expose the retroperitoneal fat. Gentle finger dissection is then performed in the retroperitoneal space, and palpation is used to identify the quadratus lumborum, the transverse process, and the psoas.
SPEAKER: The initial dilator is then placed in a transpsoas fashion using fluoroscopic guidance. The tumor may be palpated it as a firm mass within the psoas, and bony changes of the spinal column are helpful for placement of the dilator. EMG stimulation via the dilator is performed to identify location of the lumbar plexus. Sequential dilation is performed, followed by placement of the minimally invasive lateral lumbar retractor, again using fluoroscopic guidance.
SPEAKER: The Penfield no. 4, along with careful EMG stimulation, is then used for blunt dissection of the superficial psoas, exposing the tumor in the deeper muscle plane. Splitting the muscle in line with its fibers reduces traction on surrounding neural structures. The surgical microscope is used for tumor detection. We confirmed no neural activity in the most superficial aspect of the tumor, and used the bipolar artery to open the tumor capsule.
SPEAKER: Tumor forceps are used to obtain samples for frozen section, and we debulked the tumor using aspiration and pituitary forceps. In certain cases, navigation may be used to guide the tumor resection. The tumor capsule is mobilized, and cotton patties are used to preserve the plane between the capsule and the muscle. Direct stimulation is used throughout the procedure before sequential tumor debulking to confirm the absence of neural activity.
SPEAKER: The innermost portion of the tumor was fibrous and resistant to resection, so an ultrasonic aspirator or was used to continue tumor debulking. We continued to mobilize and separate the tumor capsule from the surrounding tissue. A functional nerve root was identified using direct stimulation, and careful dissection was performed to separate it from the tumor capsule.
SPEAKER: Once the excision was complete, we copiously irrigated the surgical bed and hemostasis was performed. A standard multilayer closure was performed with particular emphasis on closure of the muscle fascia, as lateral muscle wall hernias have been described after this approach.
SPEAKER: Postoperative MRI showed expected postoperative changes with no evidence of residual tumor. The patient's inpatient stay was uneventful. He developed mild, 4 out of 5, right hip flexion weakness that did not limit ambulation. We discussed prior to surgery that this could be expected and likely temporary.
SPEAKER: And this was significantly improved at the 1-month postoperative visit. The patient was discharged home on postoperative day 2 with plans for outpatient rehab.