Should I have surgery on my Achilles tendon after a high grade tear or try a nonsurgical approach?

I cut my Achilles about two months ago. The doctor just glued the outside of my heel together, because she didn't think I had injured the tendons. After an MRI two weeks ago, we discovered that i have a high grade tear to my Achilles. I'm very active, and I'm not sure what the best approach would be... surgery or casting it up for several weeks to promote healing on its own.