I was told the same pre-op. Post-op, the surgeon said he saved both sides. My PSAs have all been "undetectable" in the 19 months since, and erectile function had returned to pre-op baseline. Point is, best to worry about the things we can control. At this point, learning about penile rehabilitation and preparing a plan for that post-op will prepare you for "whatever-is", rather than worrying about "what-ifs". Good luck to you and good skill to your surgeon.