Minimally invasive keyhole approaches in spinal intradural tumor surgery: report of two cases and conceptual considerations.

Despite their predominantly histologically benign nature, intradural tumors may become symptomatic by virtue of their space-occupying effect, causing severe neurological deficits. The gold standard treatment is total excision of the lesion; however, extended dorsal and dorsolateral approaches may cause late complications due to iatrogenic destruction of the posterolateral elements of the spine. In this article, we describe our concept of minimally invasive spinal tumor surgery. Two illustrative cases demonstrate the feasibility and safety of keyhole fenestrations exposing the spinal canal.