CAS in rhino-surgical procedures in the growing age

BACKGROUND: Rhinosurgery in children and adolescents meets special requirements: Limited cooperation and reduced limits for the organ dose for ionizing radiological examinations aggravate diagnostics. On the other side, bone sutures and bone growth areas have to be respected intraoperatively, and regions of bones not yet calcified have to be distinguished from possible tumor infiltration. Computer assisted surgery (CAS) can help to identify these areas safely. METHOD: 5 patients, from the first to the 20 (th) year of life, suffering from tumors, malformation syndromes or therapy resistant nasal polyposis were treated with CAS in rhinosurgery. RESULTS: In addition to radiological diagnostics, we performed 3D computed tomography of the skull for CAS. CAS enabled us to intraoperatively respect possible areas of bone growth, to identify regions with thin, not bonily developed cranial vault and to safely distinguish bone sutures from ethmoidal cells. CAS helped the surgeon to navigate in the not yet developed paranasal sinus system. CONCLUSIONS: CAS is a useful complementary method in rhinosurgery of the developing skull of the child. In spite of the additional 3D computed tomography, the calculated organ dose of the ocular lense amounted to 5 millisievert, so a recommended maximal organ dose for the ocular lense of 15 millisievert was not exceeded.