Endoscopic lumbar disc surgery: the hammer and the nail problem or the "Not-So-Easy Go" system

Endoscopic spinal surgery using a new tubular retractor with 15 mm outer diameter

Purpose: To assess whether the instrument handling and image quality of endoscopic spinal decompression procedures is adequate and effects the treatment of degenerative spinal disorders. Material and Methods: Forty-six patients underwent endoscopic procedures for radicular pain or sensorimotor deficit due to a degenerative disorder using a 15mm tubular retractor. Endoscopic video recordings were reviewed with focus on instrument handling and intraoperative complication. At final follow-up the clinical outcome was assessed via a standardized questionnaire including the Oswestry Disability Index (ODI) Neck Disability Index (NDI), Odoms criteria and a personal examination focusing on pain, and sensorimotor deficits. Results: Forty out of 46 patients attended a final follow-up (86.9%). The mean follow-up time was 51.8 month (range 15-84 month). At final follow-up, of patients who were operate at the lumbar spine 93.9% and at the cervical spine 85.7% were free of radicular pain, no weakness was documented in 84.9% of cases after lumbar and 85.7% after cervical spine procedure, and according to Odoms criteria clinical success was noted in 84.5% and 100%, respectively. The mean ODI was 9.0% and mean NDI was 11.7%. The dural tear rate was 4.3%, all dural tear were closed endoscopically. The recurrent disc herniation rate was 6.1%. Conclusions: Endoscopic decompression using a 15m tubular retractor offers a good view onto the surgical field and a high clinical success rate. The decompression of degenerative pathologies in bimanual technique is not limited by a 15mm tubular retractor.

Complications of endoscopic microdiscectomy using the EASYGO! system: is there any difference with conventional discectomy during the learning-curve period?

BACKGROUND

Microendoscopic discectomy (MED) is emerging as a minimally invasive alternative to conventional microsurgical discectomy (MSD). EASYGO! is a new system for spinal endoscopy that claims smooth transition from MSD to MED, with a reduced learning curve period. The aims of this study were to describe the complications that appeared during the learning curve period of MED and to compare their incidence with the rate and type of complications that occurred during a simultaneous non-randomised series of standard MSDs.

METHODS

Between July 2009 and December 2010, 138 patients underwent scheduled first-time discectomy in our institution, 37 using an MED approach and 101 by a conventional MSD. A MED learning curve was obtained by plotting every case with its respective operative time. Complications, length of hospital stay, need of further surgery and outcome were prospectively recorded in both groups.

RESULTS

The mean operative time was 66 min for the MSD group and 100 min for the MED group, although for the last 14 cases of the latter group the time was reduced. Curve-fitting techniques showed that the inverse equation, ƒ(x) = 122.12/x + 73.05, had the best correlation between case number and operative time. The learning curve was overcome after the 30th case. Complications occurred in 9.8 % of the MSD group and 8.1 % of the MED group (P = 0.49). Average length of hospital stay was 2.36 days for the MED group and 3.36 days for the MSD group (P = 0.01). The procedure successfully relieved patient symptoms in 68.63 % of the MSD group and 89.92 % of the MED group. No revision surgery was required in the MED group, but it was necessary in ten patients of the MSD group.

CONCLUSIONS

Between 25 and 30 cases are needed to reach the learning curve's asymptote of MED. Even during this initial learning period MED is a safe procedure, with comparable results to those obtained with conventional MSD and with a similar complication rate. The key points for reducing intraoperative complications are an adequate expertise in MSD, a precise selection of initial cases, a proper surgical planning and a careful technique, which are mandatory to avoid unnecessary neurological injury in an otherwise secure surgical approach.