Endoscopic foraminotomy using MED system in cadaveric specimens

Study Design. Four cadavers had cervical forminotomies performed at noncontiguous levels using either the standard open technique or the microendoscopic technique. Objectives. To evaluate the feasibility of using a minimally invasive technique for posterior decompression of cervical disc disease. Summary of Background Data. Even though the anterior approach is more commonly performed for the treatment of cervical disc disease, the posterior approach has distinct advantages in selected cases of foraminal stenosis and posterolateral disc herniation. Current technique, however, requires extensive muscle dissection, and is, therefore, subject to significant morbidity. Methods. Each of four cadavers had posterior cervical foraminotomies performed using either the MICROENDOSCOPIC (MED) technique, or the standard open technique. Three noncontiguous levels were decompressed using one technique, and the other technique was used for the adjacent contralateral decompression. Each specimen was then evaluated with postoperative myelogram/CT and open dissection. Laminotomy size, length of root decompressed, and percentage of facet removed were measured. Results. Average vertical diameter decompression and percentage of facet removed were significantly greater for the MED technique than for the open technique. Transverse diameter of the laminotomy area and the average length of decompressed root were not significantly different between the techniques. Conclusion. Posterior cervical foraminotomy, using the microendoscopic technique, is technically feasible and may be applicable to the treatment of foraminal stenosis and laterally located cervical disc herniation. Studies in live animals are currently examining techniques for hemostasis.