The visualization of the surgical field in tubular assisted spine surgery: Is there a difference between HD-endoscopy and microscopy?

OBJECTIVE: Expert spinal surgeons criticized endoscopic procedures for poor image quality, in comparison to microscopic visualization. The recent introduction of high definition (HD) digital cameras has shown good results in spinal endoscopy. The aim of this study was to assess endoscopic HD image quality in comparison with microscopic visualization.

PATIENTS AND METHODS: All posterior lumbar and cervical spinal surgeries of this study were performed with the EasyGO-system in HD resolution. For each comparison, anatomical structures were predefined intraoperatively. A junior resident was randomly required to enter the operating theatre and to identify those structures either using HD-endoscopic or microscopic visualization through the endoscopic working sheath.

RESULTS: Thirteen lumbar and three cervical procedures were performed. Thirty-four comparisons with a total of 214 predefined anatomical structures were analyzed. The number of predefined structures ranged from 5 to 9 per surgical field. Out of 214 predefined structures, 124 structures (65.8%) were correctly identified under endoscopic view and 88 (41.1%) under microscopic view (p=0.001). Subjective impression of visualization quality were rated 1.25 (very good) for endopscopic images and 1.6 (very good to good) for microscopic view (p=0.02).

CONCLUSIONS: When using a working trocar and live images, endoscopic HD camera imaging accounted for significantly more reliable identifications of anatomical structures compared to the microscopic view. The subjective impression of video quality is significantly better with HD-optics. The goal of further studies should be to evalute if these findings results in improved surgical outcome.