Optimizing TESE‐ICSI by laser‐assisted selection of immotile spermatozoa and polarization microscopy for selection of oocytes

Abstract

SUMMARYFor most azoospermic men testicular sperm extraction (TESE) is the only treatment, however it presents challenges for the ART laboratory, as the retrieval of motile spermatozoa is difficult. In the absence of sperm movement no unequivocal distinction can be made between either dead or immotile, but vital spermatozoa. However, a single laser shot directed to the tip of the tail allows recognition of viability because the flagellum coils at the area of impact. To rank the quality and the maturity of oocytes, polarization microscopy can be used. The zona score and the visualization of the meiotic spindle correlate with implantation and pregnancy rates. We compared 65 TESE-ICSI cycles of the years 2007 and 2008 (Group 1, G1) with 58 TESE-ICSI cycles of the years 2009 and 2010 (Group 2, G2). Testicular spermatozoa were injected according to motility and morphology into selected oocytes. In G1 both, oocyte and spermatozoa were rated using light microscopy only, whereas in G2 the laser was used for sperm selection and the oocytes were rated by light and polarization microscopy. In G2 we enhanced our fertilization rate (FR) significantly in comparison to G1 (G1 42.1% vs. G2 52.7%, p < 0.001). The fertilization rate with immotile, but vital spermatozoa improved significantly when applying laser-based selection (p = 0.006). The laser selection of immotile spermatozoa and the use of polarization microscopy can enhance the FR of TESE-ICSI. No negative effect of the laser was seen on birth rates. The FR with immotile, but vital spermatozoa clearly benefits from laser selection and is a non-hazardous and safe method for the selection of viable but immotile sperm. To our knowledge this is the first report using new technology creating novel endpoints for the analysis of spermatozoa and oocytes in TESE-ICSI.

A new method to process testicular sperm: combining enzymatic digestion, accumulation of spermatozoa, and stimulation of motility

“…However, even TESE material characterized by total sperm immotility may be processed using a two-layer gradient as has been shown by Terriou et al [30] Viability in testicular spermatozoa could be detected by use of a laser [31]. Other authors [30,32] further restored motility by mixing it with a 1.5-7.2 mol/l solution of pentoxyphylline.…”

Processing and selection of surgically-retrieved sperm for ICSI: a review

“…Accordingly, the take home baby rate increased from 5.9 to 19.0% [66]. Increased fertilization rate after laser-assisted selection of immotile testicular spermatozoa has been confirmed recently by Nordhoff et al [67]. The use of the laser has the advantage that it does not require any chemical compound to induce motility, and thereby may be considered a safer approach.…”

A successful pregnancy using completely immotile but viable frozen-thawed spermatozoa selected by laser

“…As is known, completely immotile spermatozoa are often found in IVF treatment cycles involving ejaculate samples in patients with conditions such as primary cilia dyskinesia [91011], which is a rare autosomal recessive multisystem disorder characterized by ultrastructural and functional defects of the ciliated cells of the body. Completely immotile spermatozoa also occasionally occur in surgically extracted testicular spermatozoa [12], which can be attributed to very heterogeneous events and are a consequence of oxidative stress, infection, or numerous other factors [13]. According to the traditional freezing procedure, immotile testicular spermatozoa are likely to be abandoned and a subsequent biopsy is scheduled, which increases both the chances of long-term complications and the economic burden on the patients.…”

“…According to the traditional freezing procedure, immotile testicular spermatozoa are likely to be abandoned and a subsequent biopsy is scheduled, which increases both the chances of long-term complications and the economic burden on the patients. Many studies have demonstrated that using fresh immotile sperm for ICSI can lead to successful fertilization [912]. However, it is unclear whether immotile spermatozoa are worth cryopreserving for further ICSI.…”