Prospective evaluation of the VITOM 3D exoscope in ear surgery compared with surgical microscopes: part II—optical performance, handling, workload and ergonomics

The aim of this study was to evaluate the feasibility of a 3D exoscope system (VITOM 3D, Karl Storz, Tuttlingen, Germany) in comparison with conventional surgical microscopes (SM, hereafter referred to as ‘microscope’) in ear surgery. This paper represents the second part of a two-part publication series. A total of 62 patients were included in the study, with 31 cases assigned to the exoscope group (E+) and 31 to the conventional microscope group (E–). Surgical procedures comprised cochlear implantation (nE+ = 10, nE– = 10), reconstructive middle ear surgery for chronic otitis media with cholesteatoma (COMwC; nE+ = 11, nE– = 11), and without cholesteatoma (COMsC; nE+ = 10, nE– = 10). While the first part of the study focused on objective perioperative parameters, the present part specifically evaluates subjective outcomes as reported by the operating surgeons. These include technical aspects (perceived image quality assessed through a detailed questionnaire), surgical aspects (handling characteristics, mental and physical workload evaluated using the NASA-TLX questionnaire and ergonomic factors assessed using a questionnaire to assess localized musculoskeletal discomfort (LMD)), as well as overall satisfaction. All assessments were completed immediately after each procedure using standardized questionnaires. Additionally, a cluster analysis was performed to identify potential differences between the subgroups. The microscope received significantly better scores regarding image quality. The exoscope achieved comparable ratings for body posture and ergonomic comfort, while handling was rated slightly inferior. NASA-TLX assessments revealed no significant differences in mental or physical workload between the systems. LMD scores indicated overall low musculoskeletal strain, with only the upper back showing slightly higher discomfort in the exoscope group. Cluster analysis demonstrated heterogeneous subgroup patterns without a consistent trend, although cochlear implantation procedures were most frequently associated with less favorable subjective ratings in the exoscope group. Direct comparison of both visualization systems confirmed a slight but significant advantage of the surgical microscope in terms of system operation, visual display, and handling, while ergonomics showed no significant difference Under the conditions evaluated in this study, the investigated exoscope system did not achieve equivalence to a standard microscope across all assessed domains. In particular, limitations in optical performance and handling currently preclude its use as a full substitute for the microscope in routine ear surgery. The present findings apply to the specific system generation evaluated and the study conditions employed. Ongoing technological advancements and further refinement of exoscope systems may enable future generations to achieve equivalence with microscopes and serve as viable alternatives in routine clinical practice Our study involves a clinical trial registered at the ethics committee of the Carl Gustav Carus Faculty of Medicine at the Technische Universität Dresden, with the registration number EK 393102018. This registration reflects our commitment to transparency and adherence to international standards for clinical research.