Valve assembly for medical procedures

A valve comprising:

• an outer tube including a first material, the outer tube having an outer tube outer surface and an outer tube inner surface, the outer tube having an hourglass shape along at least a portion of a length of the outer tube;
• an inner tube including a second material different from the first material, the inner tube having an inner tube outer surface and an inner tube inner surface;
• a connector configured for connection to a pressure source;
• and
• a pressurizable space coupled to the connector, the pressurizable space being formed between the outer tube inner surface and the inner tube outer surface, the pressurizable space being configured to expand upon being pressurized, the expansion of the pressurizable space being achieved by inward deflection of the inner tube and outward deflection of the outer tube,
• wherein the valve has an introducer sheath extending therefrom and is configured to remain external to a patient and receive an implement within the inner tube while the introducer sheath is received within the patient, and further wherein the inner tube is configured to form a seal with the implement upon pressurizing the pressurizable space, the seal being sufficient to prevent back bleeding of blood under physiologic conditions past the implement through the valve.