Percutaneous intradiscal approach to the posterior annulus using a curved cannula and a flexible nucleotome – a technical note

Abstract

Automated percutaneous lumbar diskectomy (APLD) is now a widely practiced treatment of herniated lumbar disks. To be effective, however, the herniated disk must still be contained by the annulus and posterior longitudinal ligament. Only 20% of herniated disks operated on are still contained. To increase the applicability of the percutaneous approach to lumbar disk disease, a more direct manipulation of the herniated disk is necessary. Our work with a tethered cannula demonstrates the feasibility of gaining access to a posterior annular rent with the posterolateral approach to the disk that avoids the epidural space and eliminates the major problem of epidural fibrosis. We have demonstrated that a flexible suction cutting device, the minimally traumatic flexible Nucleotome, can be placed through the curved cannula and directed through the annular rent into the region of the herniation. The design of the suction cutting device of the Nucleotome is such that it maximizes the safety of such a procedure. The blunt end of the instrument, as well as the recessed port, minimizes the chance of injuring the dura by tenting it, thereby keeping it away from the port. The modified Nucleotome console with a ‘suction only’ mode coupled with an awake patient should help minimize the chance of nerve root damage. In conclusion, the cadaver experiments demonstrate the physical feasibility of approaching the posterior annulus from inside the disk using a posterolateral approach.