2.2. Surgical procedure
The surgical site was visualised with the VITOM® 3D exoscopic system
(Karl Storz GmbH, Tuttlingen, Germany). The system consisted of a 3D
high-resolution (4K) camera, a joystick, a processing module (Image 1S+
D3-LINK), and a 3D monitor (HD or 4K). The camera allowed 8 – 30x
magnification at a focal distance of 20 – 50 cm. Polarised glasses were
used to enable 3D vision.
The arrangement of the equipment relative to the operation table and the
staff is shown in Figures 1-2. The 3D monitor was placed at the eye
level of the chief surgeon and the scrub nurse. The audience consisting
of residents followed the procedure on the same screen, while the
assistant used the 2D monitor. The 3D camera was placed 30 – 35 cm away
from the surgical site (recommended minimum distance is 20 cm). The
joystick was nearby, within reach of the chief surgeon. Between
surgeries, the camera and the joystick arms were stowed safely by moving
them away from the operation table to the level of the tripod mount.
Prior to the surgeries, all staff members were instructed by an expert
technician on how to use the VITOM® 3D system. The technician
also provided support during the first surgeries. The first author was
the chief surgeon during all surgeries. Standard cochlear implantation
procedure was implemented. The initial external steps of the
intervention (skin and soft tissue incision, mastoidectomy, preparation
of an implant bone bed) were performed under conventional surgical
lighting, without any magnification. Posterior tympanotomy, electrode
insertion, and the stapedius reflex check were performed using the 3D
monitor of the VITOM® 3D system with appropriate (8 – 30x)
magnification. A ready-to-use microscope was also available. Patients
were implanted with the Nucleus system from Cochlear Limited (n = 18),
SONATA from MED-EL (n = 7), and HiRes90K from Advanced Bionics (n = 3).