Evolution of outcomes in cranial base surgery.

Cranial base surgery is a young field of head and neck and neuro-oncology. It deals with solid tumors at the skull base which were not previously treated with surgery. The development of new cranial base approaches incorporating intracranial exposure and new reconstructive techniques now enable an "en bloc" resection of most of these difficult tumors. In order to analyze the evolution of cranial base surgery and its contribution to the treatment of carcinomas and sarcomas, we reviewed the results reported in the literature over the past 40 years. We have designated three periods of time that reflect the advances and impact of skull base surgery and have summarized the outcomes of the major contributors in each era. The pioneers of the first period (1960s-1970s) achieved 3- and 5-year survivals of 52 and 49% while attempting resection of tumors without intracranial or pytergopalatine extension. In the second period (1970s-1980s), improved surgical techniques allowed resection of more extensive tumors, including intracranial invasion, and 3-year survivals rose to 57-59% with limited reports of 5-year survivals in the range of 49%. The third period of cranial base surgery (1980s-1990s) brought further refinement of techniques, introduced the concept of a coordinated multispecialty approach, and resulted in increased 5-year survivals to 56-70%.