Transnasal 3D endoscopic skull base surgery: questionnaire-based analysis of the learning curve in 52 procedures.

In the past decade, surgical treatment of skull base pathologies has greatly advanced through the advent of the endoscope and later of the high definition endoscope. Recently a new type of three dimensional (3D) scope has been introduced to permit the surgeon a real stereoscopic vision of the operating field and to overcome the limitations of the 2D endoscopic set up. As with all new technologies a formalized adaptation period is essential for the surgeon to secure steady outcomes and low complications. To determine the subjective difficulties that one may encounter during this sensitive period we therefore devised and analyzed a questionnaire that evaluated the first ten procedures with the 3D device of junior and senior ENT and neurosurgeons. 52 consecutive patients were treated with purely 3D transnasal endoscopy for skull base pathologies. Sensation of strain or dizziness, difficulties in anatomical orientation and difficulties in performing the surgical gesture were assessed for each surgeon. The learning curve and difficulties of junior and senior surgeons are discussed and strategies to overcome the initial problems are devised. Our results confirm that after only few procedures, the advantages of the 3D endoscopic system including better visualization and depth perception are able to outweigh the inconveniences that go hand in hand with the learning of a new skill set.