Instrument, instrument head, application system and method

An instrument comprising:

• a nozzle having a first section defined by a first interior cross-sectional diameter and a nozzle opening, and a second section defined by an interior diameter greater than the first interior cross-sectional diameter and having an interior conical shape;
• and
• a tube within the nozzle extending from the second section of the nozzle into the first section of the nozzle, the tube comprising a cylindrical end with an opening that opens within the first section of the nozzle upstream from the nozzle opening of the first section, whereby
• an area extending from the opening of the cylindrical end of the tube and the nozzle opening of the first section defines a reacceleration zone,
• the tube is configured to deliver a first fluid in an axial direction of the instrument to the reacceleration zone at a first velocity sufficient to form a channel in a tissue,
• the second section of the nozzle configured to accelerate a flow of a second fluid upstream from the reacceleration zone and to deliver the second fluid to the reacceleration zone,
• wherein the reacceleration zone is fluidically connected to both an inside of the tube and the second section of the nozzle at a same time.