Radially expandable introducer sheath

A medical device system, comprising:

• a replacement heart valve delivery system;
• and
• an introducer sheath comprising a tubular member comprising an inner layer and an outer layer coaxially disposed about a central longitudinal axis of the introducer sheath, the tubular member being configured to shift between an unexpanded configuration to an expanded configuration;
• wherein the inner layer is circumferentially discontinuous along at least a portion of its length;
• wherein at least a first portion of the inner layer is configured to slide circumferentially relative to the outer layer when shifting between the unexpanded and expanded configurations;
• wherein the outer layer is circumferentially continuous along its entire lengths wherein the inner layer is formed from a substantially inelastic material;
• wherein the replacement heart valve delivery system is configured to slide within a lumen of the introducer sheath for advancement within a vasculature.

A method of delivering a replacement heart valve, comprising:

• advancing an introducer sheath through a vasculature to an access site, the introducer sheath including a tubular member comprising an inner layer and an outer layer coaxially disposed about a central longitudinal axis of the introducer sheath;
• the tubular member being configured to shift between an unexpanded configuration to an expanded configuration;
• wherein the inner layer is circumferentially discontinuous along at least a portion of its length;
• wherein at least a first portion of the inner layer is configured to slide circumferentially relative to the outer layer when shifting between the unexpanded and expanded configurations;
• wherein the outer layer is circumferentially continuous along its entire lengths wherein the inner layer is formed from a substantially inelastic material;
• inserting a replacement heart valve delivery system into a lumen of the introducer sheath;
• advancing the replacement heart valve delivery system through the lumen of the introducer sheath to a treatment site;
• wherein the introducer sheath radially expands as the replacement heart valve delivery system is advanced through the introducer sheath;
• and
• deploying the replacement heart valve at the treatment site.