A surgeon beyond his era: neurosurgical contributions of Eugène-Louis Doyen (1859-1916).

Eugène-Louis Doyen studied medicine in Reims and Paris, further refining his surgical approach through experiences in Heidelberg, Würzburg, and Vienna. Recognized in French surgery for his innovations across thoracic, abdominal, and gynecological disciplines, his critical contributions to early neurosurgery, particularly trigeminal neuralgia treatment, remain significantly underexplored. Combining elements from the Hartley-Krause subtemporal route and the Rose sphenoidal route, he developed an advanced trigeminal ganglionectomy technique to minimize complications. Doyen introduced the electric craniotome, instruments specifically designed for dural detachment, and specialized devices to enable precise en bloc ganglion removal, thereby enhancing surgical safety and efficiency. He developed a minimally invasive retrosigmoid craniotomy approach using a speculum and custom neurotome to sever the sensory trigeminal root. This groundbreaking cerebellopontine angle endoscopy technique substantially reduced invasiveness compared to more extensive gasserectomy procedures. Despite the considerable controversy stemming from his abrasive personality, unorthodox methods, and provocative practices, such as filming surgical procedures, Doyen's bold innovations advanced neurosurgical techniques at the turn of the 20th century. Examining his career offers essential insights into a pivotal transitional era when ambitious operations on the brain began evolving into more precise, organized, and effective neurosurgical practices.