549 Use of 3D Printing Technology in Surgical Planning and Decision Making in ENT Skull Base Surgery- An Axial 3D First in Northern Ireland

39-year-old male seen at ENT clinic with inverted papilloma polyp of nasal sinus. CT showed multi-sinus mucosal thickening. The surgical options discussed were modified Lothrops endoscopic sinus surgery or an open approach of frontal sinuses with osteoplastic flap and septorhinoplasty. A model 3D skull was created by Axial 3D using stereolithography 3D printing technology with photopolymer resin. The skull was made in 1:1 scale with tolerance of 0.2mm. The tumour was printed in a contrasting colour, which allowed clear visualisation and appreciation of tumour boarders and relations to surrounding structures. The patient underwent FESS with modified Lothrops approach, achieving good clearance of polyp. The operation resulted in relief the patient’s symptoms. Discussion The use of a 3D model allowed for visualisation of tumour size and relation to surrounding anatomy, particularly the absence of dural involvement within the fontal sinus. It assisted in surgical planning. The use of the 3D skull was beneficial for patient as it allowed less invasive surgery and therefore shorter recovery time. It was also beneficial for the hospital organisation as it lowered resource requirements of theatre time, hospital bed days and staff resources. One limitation of the 3D printed skull was that the fine lamellae ethmoid air cells were not shown due to the manufacturing process. Conclusions The use of 3D printing is becoming increasingly popular as a surgical aid. We found the use of the 3D skull to be useful in individualised surgical planning for endoscopic sinus surgery.