Use of a tubular retractor system in microscopic lumbar discectomy: 1 year prospective results in 135 patients

Abstract

Application of minimally invasive techniques to lumbar disc surgery has led to the development of the Microscopic Endoscopic Tubular Retractor System (METRx-MD). A prospective evaluation of results and complications was undertaken. One hundred thirty-five patients underwent surgery in which the METRx-MD system was used; most procedures were performed on an outpatient basis, and general anesthesia was induced in all cases. All patients were followed prospectively. Outcomes were measured using a visual analog scale (VAS), the Oswestry Disability Index (ODI), and the Short Form-36 (SF-36) questionnaires. Follow-up data were collected by an outside company, which also tabulated the data. Data were collected in 129 of 135 patients. Improvement was seen on the VAS (Scores 7-2), ODI (Scores 57-16), and SF-36 scales (bodily pain Scores 20-60). Patient satisfaction with results was 94% and with office services 88%. Thirty-six percent of patients returned to work at 0 to 2 weeks, 38% at 3 to 5 weeks, and 25% at 5 to 26 weeks. Hospital charges decreased by $2395 (18%). The mean operative time was 66 minutes, and the mean blood loss was 22 ml. Complications included one superficial wound infection, one discitis, three durotomies, and three cases of excessive bleeding (> 100 ml). There were five reoperations: four for recurrent disc herniations, (two ipsilateral and two contralateral to the index site) and one for spinal stenosis contralateral to the index site. Minimally invasive surgery in which the METRx-MD system is used is clinically effective and cost effective. Patient satisfaction was high. A mean per case cost savings of $2395 was realized. Complications rates were comparable with those associated with traditional microdiscectomy procedures.