Hollow needle

A method for creating a puncture hole in a blood vessel of a patient and widening said puncture hole for introducing a catheter into said blood vessel, comprising the steps of:

• providing a hollow needle comprising a tip located at a distal end of said hollow needle, a first outer diameter located in a first region adjacent said tip and a second outer diameter located in a second region located at a longitudinal distance further away of said distal end than said first region, said second outer diameter being greater than said first outer diameter;
• puncturing said blood vessel using said tip of said hollow needle in order to create said puncture hole;
• introducing said first region and at least a part of said second region through said puncture hole into said blood vessel in order to widen said puncture hole, wherein, after completing said step of puncturing said blood vessel, said tip remains in said blood vessel until completion of said step of introducing said first region and said part of said second region.

A method for creating a puncture hole in a blood vessel of a patient and widening said puncture hole for introducing a catheter into said blood vessel, comprising the steps of:

• providing a hollow needle comprising a tip located at a distal end of said hollow needle, a first outer diameter located in a first region adjacent said tip and a second outer diameter located in a second region located at a longitudinal distance further away of said distal end than said first region, said second outer diameter being greater than said first outer diameter;
• puncturing said blood vessel through said tip of said hollow needle in order to create said puncture hole;
• introducing said first region and at least a part of said second region through said puncture hole into said blood vessel in order to widen said puncture hole, wherein said steps of puncturing said blood vessel and introducing said first region and said part of said second region are performed by one substantially continuous movement without removing said tip before introducing said first region and said part of said second region.