New Implants and Techniques in Minimally Invasive Spine Surgery: True Percutaneous Transforaminal Lumbar Interbody Fusion (pTLIF) with the Posterolateral Transforaminal Endoscopic Approach

Abstract

The standard treatment for degenerative disk disease is interbody fusion by open discectomy. However, this technique requires open tissue dissection with the disadvantages of higher risk of infection, blood loss and a relatively long recovery period.

The posterolateral transforaminal approach is the standard approach in endoscopic spine surgery that allows direct access to the intervertebral disk with progressive tissue dilatation and no tissue dissection. In this chapter, we present the posterolateral approach to percutaneously insert an interbodyimplant (PEEK rigid cage, as well as B-Twin and Opticage expandable devices) into a lumbar disk. The implants can be inserted either as a stand-alone cage or with a posterior fixation with the goal to achieve a 360° interbody fusion. A typical indication for this technique are patients suffering from degenerative disk disease with or without spondylolisthesis in the lumbar spine. The percutaneous transforaminal posterolateral fusion approach is also helpful for revision surgery as it allows bypassing fibrous tissue generated by previous open surgery. In selected cases, central spinal stenosis can also be successfully addressed with this technique without additional open posterior decompression surgery, by employing an expandable device that opens the central canal with indirect decompression. t.

In a first part, we will review our previous experience with various interbody implants (PEEK rigid cage and the B-Twin expandable device) that were percutaneously inserted in the lumbar spine with the aforementioned endoscopic transforaminal approach. Based upon this experience, we will then explain the development process of a whole new set of instruments (Optiport) and a new expandable device (Opticage) to optimize and streamline percutaneous spine fusion surgery with a method that we call percutaneous transforaminal lumbar interbody fusion (pTLIF). We present a single-center, single-surgeon prospective study of 40 consecutive pTLIF cases using the Opticage expandable device. The outcome of this study showed a significant (p < 0.001) decrease between pre-operative and post-operative pain and disability scores for a mean follow-up of 33.4 ± 20.6 months. Our results show the efficacy of the posterolateral approach to safely and quickly achieve a percutaneous fusion of the lumbar spine and successfully treat patients with degenerative disk disease with or without spondylolisthesis up to grade 2 and in revision surgery. Our outcome does not differ from standard open surgery, while the advantages of the pTLIF procedure comprise less invasiveness with lower risk of bleeding and infection, as well as a shorter time to post-operative walking (median 6h) and hospital discharge (median post-operative time until hospital discharge 25h). This disruptive percutaneous fusion technique opens the way for ambulatory lumbar spinal fusion surgery in an out-patient setting.