Cranial trepanations were made to address complex lesions. The evidences of operations show that the surgeons only removed the damaged parts of the skull without damaging the cerebral membrane.
It spans from the initial periods, around 700 B.C., to. 200. A.C
Region: North Coast
These trepanations were made by specialized surgeons, who removed fragments of the skull and covered it with gold and silver foils.
They also performed Cranial deformations (used only for important people).
These used Obsidian knives. Tello states that 40% of the mummies had undergone trepanation practices, and that they were carried out while alive.
There is evidence that in pre-Columbian medicine a high percentage of patients with trepanned skulls recovered, possibly due to the use of medicinal plants to prevent infections and inflammation. Also medicinal analgesics to reduce pain during the surgery. Remains of these plants have been found next to bone remains.
The instruments may have been "obsidian" and "wedge-shaped volcanic glass blades." In addition to the skulls, bandages were found as cloths, cotton rolls, in the form of a thread and bandages made of very soft cotton fabric, which contributes to the criterion of the existence of a surgical method next to trepanation. The research highlighted that in the series of 400 skulls studied by Tello, it was found that 250 of them were surely "cured" (65%)