Expandable introducer sheath

Introducer sheath for catheters to be inserted into a vascular system, said sheath comprising a connecting valve (2) and an insertion tube (3) having a proximal portion (4) and a distal portion (5), said distal portion (5) being of reduced diameter in comparison with the proximal portion (4), wherein the insertion tube (3), in order to enable its diameter to be reversibly changed, is provided with

• (i) longitudinally extending first expansion elements with first incisions (11, 11′) designed as predetermined breaking points, said first incisions extending from the proximal end of the distal portion (5) to a position adjacent to the distal end of the distal portion (5);
• (ii) longitudinally extending second expansion elements with second incisions (12), said second incisions originating from the distal end (10) of the insertion tube (3) and extending in a distal area (7) of said tube.