What happens if the psa test shows more than 0 after prostatectomy?

Tissue remains: It may be that not all of the prostate tissue was removed. Many surgeons do a nerve sparing prostatectomy -- but this means that small amounts of prostate tissue may remain. Alternatively, if the level continues to increase, then there is a risk of metastatic disease, that should be further evaluated.

Psa: This is called a psa recurrence and you need to discuss with utolohist.