Seeing pulsation of the artery at the completion of this dissection.

1. This is a run-on that can be fixed with a period.
2. This is a run-on that can be fixed by adding a comma and a conjunction.
3. This is a fragment that can be fixed by adding a subject and verb after this long introductory element.
4. This is a fragment that can be fixed by removing the word seeing from the beginning of the sentence.
5. The sentence is fine as it is.

Answer:
Not #1. tried #2 - no #4 removing seeing - it is not a sentence.
Answer - #5.
Thanks for all your help.

You forgot #3...the correct answer. :P

You're welcome! I'm glad I could help. To explain further, when analyzing the given sentence, we can see that it has a complete subject ("Seeing pulsation of the artery") and a predicate ("at the completion of this dissection"). Therefore, it is a complete sentence and does not require any corrections. Therefore, the correct answer is #5 - "The sentence is fine as it is."