WARNING: GRAPHIC CONTENT. Researchers in Japan found that transplanting the testes to the neck is ‘more simple and reproducible,’ with potential to improve the success rate.
Scientists have successfully conducted testicle-to-neck transplants in rats, in a breakthrough that could one day help preserve fertility in human cancer patients.
Testes are known to be ‘immunologically privileged,’ meaning they are able to resist rejection after a transplant.
But, the technical difficulty of transplanting the organ means experimental procedures of this kind have so far been ‘extremely limited.’
Now, researchers in Japan have discovered that transplanting the testes to a different part of the body is ‘more simple and reproducible,’ with potential to cut down operation time and improve the success rate.
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In the new study, the researchers from Tokyo Medical University and Aichi Medical University investigated how transplanted testes can survive in a recipient’s cervical region (or, the neck) .
Earlier efforts have shown that, when transplanted into immunodeficient animals, a donor’s testes can continue to create sperm to some degree.
But, the researchers explain, ‘it is important to determine how grafts of testicular cells, tissues, or whole organ are immunologically accepted or rejected in “immunocompetent” recipients,’ meaning those with normal immune function.
To find out, the team performed two types of procedures: orthotopic testis transplantation (OTT) , in which the testes are transplanted into their normal place, and heterotopic testis transplantation (HTT) , which, in this case, saw the testes transplanted into the neck.
The researchers performed the unconventional HTT procedure on 12 rats – and, this yielded a 100 percent success rate.
The OTT procedure, on the other hand, had a success rate of 71 percent.
And, in addition to the higher success rate, the testicle-to-neck operation turned out to be ‘significantly shorter,’ taking an average of about 60 minutes to complete, compared with the 154 minutes seen in the OTT operations.
Still, the researchers identified three issues that ‘must be considered’ in the cases where the testes had been put into a recipient’s neck: the potential temperature difference, blood flow disturbance as a result of folding the testicular vessels, and drainage of the vas deferens.
According to the study, published to PLOS One, the work is a step toward better understanding testicular immunology.
This could, in turn, help to create better methods for people who endure medical procedures that hinder the production of sperm.
‘Chemotherapy or radiation therapy for malignant cancers often injure the spermatogenesis of young patients,’ the authors wrote.
‘In particular, prepubertal patients may suffer from permanent infertility because mature spermatozoa in semen cannot be cryopreserved prior to therapy.
‘Thus, transplantation of children’s testes and epididymides to their fathers or brothers before receiving medical therapy may be helpful for obtaining mature spermatozoa from the transplanted testes at a future date.
‘It is also possible that the transplanted testes in recipients are transplanted back into donors after medical treatment.’
