Incan trepanations have made headlines about high survival rates compared to American civil war craniotomies, based on research such as the one presented by Kushner, Verano et al. at the 2017 AAN annual meeting and later published in the World of Neurosurgery in 2018. The objective is to take these findings one step further comparing those survival rates with contemporary procedures to understand where the data aligns and the possible significance of the results.

Incan trephined skulls were selected for this comparison not only because they made headlines but because they represent the single largest collection of samples known to date. To define the selection as Incan the skulls were limited to the Central and Southern highlands of modern day Peru and between the years 1000-1450CE. For the contemporary comparison, five studies of craniotomy survival rates were chosen which had taken place after the year 2000CE and showcased a diversity of populations.

A direct comparison of survival rates was done between the Incan procedures and five contemporary series of data which met the following criteria: a substantial number of subjects surveyed, relative comparability in terms of the procedures, geographical diversity of occurrence and the possibility of accurately calculating survival rates.

The results revealed that Incan trepanations showed an average 73.7% survival rate, while contemporary craniotomies showed a 74.2% survival rate. Limitations to acknowledge are the absence of written records among the Incas and ultimately not knowing why they performed these trepanations.