A lead anchor includes a lead lumen forming a continuous passageway through an inner housing. A fastener lumen extends along the inner housing and forms an intersection with the lead lumen. A lead-retention assembly removably retains a lead within the lead anchor. The lead-retention assembly includes a sleeve formed from a rigid material. The sleeve is disposed within the lead lumen at the intersection between the fastener lumen and the lead lumen. The sleeve lumen receives the lead when the lead is received by the lead lumen. A fastener is disposed in the fastener lumen and retains the received lead within the lead anchor by pressing against the sleeve to reduce the diameter of the sleeve at the intersection between the fastener lumen and the lead lumen by reducing the width of a longitudinal cutout defined along the sleeve at the intersection between the fastener lumen and the lead lumen.