Endoscopic foraminotomy using MED system in cadaveric specimens

Study Design. Four cadavers had cervical forminotomies performed at noncont iguous levels using either the standard open technique or the microendoscop ic technique. Objectives. To evaluate the feasibility of using a minimally invasive techn ique for posterior decompression of cervical disc disease. Summary of Background Data. Even though the anterior approach is more commo nly performed for the treatment of cervical disc disease, the posterior app roach has distinct advantages in selected cases of foraminal stenosis and p osterolateral disc herniation. Current technique, however, requires extensi ve muscle dissection, and is, therefore, subject to significant morbidity. Methods. Each of four cadavers had posterior cervical foraminotomies perfor med 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 decompres sion. Each specimen was then evaluated with postoperative myelogram/CT and open dissection. Laminotomy size, length of root decompressed, and percenta ge of facet removed were measured. Results. Average vertical diameter decompression and percentage of facet re moved were significantly greater for the MED technique than for the open te chnique. Transverse diameter of the laminotomy area and the average length of decompressed root were not significantly different between the technique s. Conclusion. Posterior cervical foraminotomy, using the microendoscopic tech nique, is technically feasible and may be applicable to the treatment of fo raminal stenosis and laterally located cervical disc herniation. Studies in live animals are currently examining techniques for hemostasis.