Are there any complications due to Botox being injected into a vein that I should be concerned about?

Botox will not cause a problem if injected inadvertantly into a vessel, but puncture through the vessel can cause swelling, bruising and pain that can persist for a few weeks.  Best, Dr. Emer.

Bruising can be worse when a vein is damaged with the injection, and you may also feel a bit of a headache. Both will subside with time.

You may experience some additional bruising if the botox is injected into a vein, but nothing more. Botox is a very safe treatment that is temporary. I hope this has helped to ease your concerns.- Dr. Bryson Richards

If significant amounts of botox is injected into a vein, other problems would occur with breathing, etc. Otherwise, 'hitting a vein' can cause more bruising than usual but nothing more than that. 

When an injector hits a vessel when injecting Botox, you would likely have a bruise for a short while. Beyond that, no complications are anticipated from the Botox reaching the blood stream due to the very small amounts usually injected. The bruise should settle down within a few days. Good luck!

You should not be concerned. The amounts used in Botox for cosmetic purposes are very small. Additionally, the vein that was hit was very, very thin and most likely, the vein was nicked and the Botox wasn't actually put into it. Even it it were injected into the vein, it would not affect you negatively. You have a bruise and swollen spot because the vein was hit. It will go away. And you won't have negative effects from the Botox there. It's ok. "This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."