VALVED INTRODUCER SHEATH

A valved introducer sheath (1) having a valve housing (17, 18) with a through-lumen and an inflatable cuff (2, 60, 70) disposed in the valve housing that can be inflated to occlude the through-lumen, is described. The device has an overflow tube (30) in fluidic connection with the inflatable cuff having a resiliently deformable overflow chamber (34). When the inflatable cuff is filled with inflation liquid, the cuff partly or fully occludes the through-lumen, thereby preventing blood pass through the lumen. When an interventional device is pushed through the lumen for use in a medical procedure, the pressure forces liquid from the cuff into the overflow tube, allowing the cuff to partly deflate. As the overflow chamber is resiliently deformable, the liquid is pressurised which maintains a seal between the inflatable cuff and the interventional device. Upon removal of the interventional device from the lumen, the overflow tube pushes fluid back into the cuff, allowing it to reinflate fully.