A high-definition 3D exoscope as an alternative to the operating microscope in spinal microsurgery

Since the 1970s, the operating microscope (OM) has been a standard for visualization and illumination of the surgical field in spinal microsurgery. However, due to its limitations (e.g., size, costliness, and the limited movability of the binocular lenses, in addition to discomfort experienced by surgeons due to the posture required), there are efforts to replace the OM with exoscopic video telescopes. The authors evaluated the feasibility of a new 3D exoscope as an alternative to the OM in spine surgeries.

Patients with degenerative pathologies scheduled for single-level lumbar or cervical spinal surgery with use of a high-definition 3D exoscope were enrolled in a prospective cohort study between January 2019 and September 2019. Age-, sex-, body mass index-, and procedure-matched patients surgically treated with the assistance of the OM served as the control group. Operative baseline and postoperative outcome parameters were assessed. Periprocedural handling, visualization, and illumination by the exoscope, as well as surgeons' comfort level in terms of posture, were scored using a questionnaire.

A 3D exoscope was used in 40 patients undergoing lumbar posterior decompression (LPD) and 20 patients undergoing anterior cervical discectomy and fusion (ACDF); an equal number of controls in whom an OM was used were studied. Compared with controls, there were no significant differences for mean operative time (ACDF: 132 vs 116 minutes; LPD: 112 vs 113 minutes) and blood loss (ACDF: 97 vs 93 ml; LPD: 109 vs 55 ml) as well as postoperative improvement of symptoms (ACDF/Neck Disability Index: p = 0.43; LPD/Oswestry Disability Index: p = 0.76). No intraoperative complications occurred in either group. According to the attending surgeon, the intraoperative handling of instruments was rated to be comparable to that of the OM, while the comfort level of the surgeon's posture intraoperatively (especially during "undercutting" procedures) was rated as superior. In cases of ACDF procedures and long approaches, depth perception, image quality, and illumination were rated as inferior when compared with the OM. By contrast, for operating room nursing staff participating in 3D exoscope procedures, the visualization of intraoperative process flow and surgical situs was rated to be superior to the OM, especially for ACDF procedures.

A 3D exoscope seems to be a safe alternative for common spinal procedures with the unique advantage of excellent comfort for the surgical team, but the drawback is the still slightly inferior visualization/illumination quality compared with the OM.