Abstract: The present disclosure relates generally to methods and apparatus to control delivery of a sealant during an invasive procedure. Disclosed methods and apparatus control movement of a syringe to control injection of sealant stored therein. For example, disclosed methods and apparatus can displace the syringe body relative to the plunger as the syringe is withdrawn from the target site, rather than displacing the plunger relative to the syringe body, to thereby pressurize the sealant or inject the sealant in an amount proportional to a distance the syringe body is withdrawn. This reduces the variability in the amount of sealant delivered along the syringe withdrawal pathway. The disclosed methods and apparatus can increase precision in movement of a syringe, thereby increasing precision in sealant delivery.