Transforaminal Full-Endoscopic Lumbar Foraminotomy Under Local Anesthesia for L5/S1 Adjacent Segment Foraminal Stenosis

In this paper, we described adjacent level foraminal stenosis, and we treat the problem using an endoscope. The most problematic pathology is alpha spondylolisthesis with past fracture. That is very difficult case.

So basically we need the fusion, but finally, using the endoscope, we developed the most novel technique, criss-cross compression. For adjacent segment foraminal stenosis, at L five S one, fusion extension was often the only option. Our protocol offers a motion preserving, reproducible endoscopic alternative.

Our protocol enables consistent reproducible decompression with minimal fluoroscopy and reduce patient burden, compared to conventional techniques. To begin, establish an intermittent antero posterior and lateral fluoroscopic view at the desired site, and advance the 23 gauge needle along the planned trajectory toward the S one superior articular process. Incrementally infiltrate approximately seven milliliters of 1%lidocaine solution into the paraspinal muscles and soft tissues along this pathway, then switch to an 18 gauge 200 millimeter needle for targeted deep infiltration of anesthesia.

Under continued intermittent fluoroscopic guidance, advance the needle to the next anatomical targets. Inject two milliliters of 1%lidocaine into the L five S one facet joint capsule. Next, inject two milliliters into the tip of the S one superior articular process, and two milliliters into the middle portion of the S one superior articular process.

Then inject two milliliters of lidocaine onto the S one superior end plate if safely accessible. Advance the needle tip to the surface of the L five S one annulus fibrosis. Confirm satisfactory needle positioning with an AP fluoroscopic view, then inject approximately two milliliters of lidocaine onto the annular surface.

Further advance the needle into the L five S one disc space and inject an additional two milliliters of lidocaine. Now inject one to two milliliters of indigo Carmine solution into the disc space for staining, if disc material identification is anticipated to be critical. Insert the initial blood tip serial dilator through the eight millimeter skin incision along the anesthetized trajectory.

Under intermittent AP and lateral C-arm fluoroscopic guidance, sequentially advance the serial dilators with gentle rotating movements toward the lateral aspect of the S one superior articular process. Confirm that the tip of each dilator is accurately positioned on the bony surface of the S one superior articular process, ideally at the junction of the SAP and pedicle. Next, advance the beveled working cannula with eight millimeters inner diameter, and 165 millimeters length over the final dilator until it is firmly docked on the lateral aspect of the S one superior articular process.

Confirm the final cannula position using AP and lateral fluoroscopy. On the AP view, dock the cannula on the lateral aspect of the superior articular process. On the lateral view, position the cannula tip at the posterior aspect of the foramen, directly overlying the SAP.

Now carefully remove the final dilator, leaving the working cannula in place as the operative portal. With the lateral aspect of the S one superior articular process clearly visualized, commence the foraminoplasty using a high speed, endoscopic drill. Start drilling at the coddle base of the S one superior articular process, at its junction with the S one pedicle.

Then systematically resect the ventral and cranial portions of the S one superior articular process. Drill in a coddle to cranial direction, gradually shaving the superior articular process from its base towards its tip. Unroof the L five S one foramen dorsally and laterally to expose the underlying ligamentum flavum, and decompress the exiting L five nerve root.

Continue drilling until approximately 80 to 90%of the hypertrophied portion of the superior articular process is resected, and the foraminal ligamentum flavum and the shoulder of the L five exiting nerve root are sufficiently exposed. Using the high speed endoscopic drill, carefully resect a portion of the ventral aspect of the L five inferior articular process. To perform the detached technique, press the cranial half of a spherical bur tip against the bony edge of the S one superior articular process at the ligament's insertion point.

Employ a rotational shaving motion to resect this bone, while simultaneously pulling the drill proximally to direct the resection away from the thecal sac and safely release the ligamentum flavum. Observe the detached ligamentum flavum for pulsation. Finally, grasp the free floating detached ligamentum flavum with a 3.5 millimeter carisin punch or endoscopic ronjurs.

Carefully remove the ligament from the foramen, and observe the decompressed nerve root. Preoperative magnetic resonance imaging confirmed right-sided L five S one foraminal stenosis with compression of the exiting L five nerve root due to a herniated nucleus pulposus. Preoperative computed tomography scans showed severe foraminal narrowing at L five S one caused by a hypertrophied superior articular process.

Postoperative computed tomography images demonstrated successful decompression with resection of the ventral cranial portion of the superior articular process, and visible enlargement of the L five S one foramen.