Complex sentence: In case of failure with PVS, spermatozoa are sometimes collected by electroejaculation, or surgically by per cutaneous epididymal sperm aspiration or testicular sperm extraction.
Split into simpler sentences: In case of failure with PVS, spermatozoa are sometimes collected by electroejaculation. Failing that, sperm can be surgically removed from the testicle by per cutaneous epididymal sperm aspiration or testicular sperm extraction.