Anti-microbial medical injection assemblies for onabotulinumtoxina delivery and methods of use thereof

A method for treating overactive bladder comprising:

• (a) inserting an endoscope into a scope lumen of an introducer, wherein an optically-clear, fluid-tight cap attached to the distal end of the scope lumen is configured to isolate the endoscope from the external environment;
• (b) inserting a cannula into a cannula lumen of the introducer, the cannula configured such that the distance between the distal tip of the cannula and the axis defined by the sheath of the introducer increases as the cannula is moved in a distal direction, wherein a syringe filled with OnabotulinumtoxinA is coupled to the proximal end of the cannula;
• (c) guiding the introducer through the urethra of a patient to the patient's bladder;
• (d) extending the distal portion of the cannula past the distal end of the introducer until a needle attached to a distal end of the cannula is placed at a desired radial distance from the axis defined by the sheath of the introducer;
• (e) rotating the introducer to position the needle at a desired position;
• (f) moving the introducer in a distal direction to insert the needle into the bladder;
• (g) activating the syringe to inject OnabotulinumtoxinA into the bladder;
• (h) moving the introducer in a proximal direction to remove the needle from the bladder;
• (i) repeating steps (d) through (h) until a therapeutically effective amount of OnabotulinumtoxinA has been injected in a therapeutically effective pattern into the bladder.