Male genetic infertility: HRSS? MESA?

Hello,

My partner has a male genetic infertility problem: most of his sperm do not carry DNA. Some sperm carry half of DNA and very few sperm carry normal DNA. His sperm has normal morphology values. In 2003, with his previous partner, they tried several insemination and in-vitro fertilization through ICSI (with testicular open biopsy and sperm hand-selected at about a magnification of 500x based upon Motility and Morphology). All trials were unsuccessful because no egg fertilized.

We want to know whether we should try:
- HIGH-RESOLUTION SPERM SELECTION (HRSS)
- Microsurgical Epididymal Sperm Aspiration (MESA)? We understand the above will then be followed by intra-cytoplasmic sperm injection (ICSI).

In addition, I have one question: Is Flow Cytometry only used for differentiating chromosomes X and Y (because FISH uses DNA probes that specifically attach to either the X or Y chromosome in sperm) or can this technique be used in our case (to measure quantity of DNA in the sperm)?

Thank you