Injection therapy catheter

Claim 1

An injection therapy catheter for endoscopically guided introduction of injectable fluid agents such as blood coagulants and vasoconstrictors into selected sites within a body, said injection catheter sized for passage through a working channel of an endoscope and constructed to be maneuvered therethrough to a site at which, for instance, bleeding may occur, said injection catheter including a needle lumen terminating at a distal end of said catheter in a distal needle port, an extendable and retractable needle catheter slidably disposed in said needle lumen and terminating distally in a tissue-penetrable hollow needle, said needle projectable and retractable relative to said needle port by actuating motion applied to a proximal end of the injection catheter, said needle adapted for penetration of tissue at a location determined by visual examination by the physician through the endoscope for injection of said injectable fluid agents, said injection catheter including a visual-path irrigation lumen, the distal outlet thereof being located adjacent the needle port and directed to introduce clear irrigation fluid in a flow that enhances the visual path from the associated endoscope to tissue near to which the distal end of said injection therapy catheter has been advanced, thereby to displace fluid containing blood or other obscuring substance from a potential target site at said tissue and enable the physician in a one-catheter procedure to clarify the visual path, endoscopically identify a target injection site, advance said needle into the tissue at said site and inject said injectable agent.