Several randomized trials comparing i.v. therapy alone v.s. i.v. and i.a. therapy have been conducted. These include the EMS bridging trial(Lewandowski), the IMS trial( Tomsick), and the IA/IV trial (Keris).
These trials generally showed increased rates of recanalization with combined therapy (without significant increased morbidity) and improved outcomes for combined therapy in 2 of the 3 trials.
Time is also a factor in ICH. The later treatment is instituted, either with IV or IA therapy, the more likely that ICH will occur.
With IA therapy, increasing dose also increases the ICH risk, though different trials have reported varying rates of increase. Interestingly, ICH is not always symptomatic, and many studies show increased overall benefit despite increased symptomatic hemorrhage.
Acute stroke treatment is where acute MI treatment was when the Seattle CPR project started. When people become aware that there is urgent treatment for this disease, they will seek it out and it will become standard of care.
If you treat an acute stroke and watch a patient’s speech return, or watch a hemiparetic patient start moving and get up off your ER bed or angiography table you will never feel anything quite like it in your medical career.