In the Ear-Nose-Throat (ENT) Division of the Department for Head and Neck Surgery at the University Hospital of Antwerp (UZA), the computer has become a loyal companion for operations relating to the sinus cavities in the skull. These cavities, situated near the nose for example, are separated by slice-thin walls. When a bone tumour has to be removed from the sinuous cavity in the forehead, the surgeon must be very careful not to penetrate by accident the cranial cavity. The surgical clearance of a stuffed sinus in the case of chronic sinusitis, which makes the patient suffer from inflammation of one or more of the sinuses, has to be performed without inflicting damage to the sinus wall. The new computer assisted surgery system substantially reduces the risk to make any mistakes.
Professor Jos Claes, a surgeon in the ENT Division at UZA, works together with the neurological surgeon to perform interventions via the nose to the gland, that is situated below the brain and plays a crucial role in the secretion of various hormones. The surgeon has to approach the optic nerve at a distance of a few millimetres. Touching the optic nerve would cause the patient to be struck with blindness. The computer images are a safe guide in leading the surgeon to the exact target. The CAS system enables the surgeon to accurately trace the gland with a deviation of less than half a millimetre.
In turn, Dr. Erwin Koekelkoren has acquired a great expertise in placing auditory prostheses implants in the patient's skull by attaching the device to the bone. In fact, the implant is being attached to a titanium screw, that is driven into the bone. The screw has to be fixed to massive bone which is very difficult to find in the auditory area. In the past, the surgeon was forced to try a number of times before the screw could be adequately fixed. Currently, the CAS system allows to search for a suitable spot on the 3D digital image as well as for the right direction of the trepanation. As a result, the patient is spared from unnecessary holes in the skull. Moreover, in dental surgery, the same techniques are being applied to implant dental prostheses into the tooth bone.
In the near future, the UZA Department of Head and Neck Surgery plans to use the computer system for the removal of tumours, located on the auditory nerve. According to the results of a research study carried out by Professor Claes, the head and neck surgeons at UZA indicate six anatomic landmarks previous to their computer assisted operations to the skull. Four of them are situated at the front of the skull bone and two at the back. This allows for an excellent matching between the skull and the computer images. Instead of fixing the patient's head to a stereotactic frame to avoid unexpected motions, the patient receives an oral device equipped with light emitting diodes (LEDs) which serves as a reference base. As such, the new technology is taking the patient's comfort to heart as a matter of "capital" importance.