Has some diagnosis been arrived at like varicocele
?( as you have mentioned about the tortuous veins along with oligospermia
with abnormal sperms) .The cause needs to be treated for a permanent solution. If it is varicocele, surgery is the best option. In case there is no known cause medicines are available in homeopathy
which can help in improving the sperm count
Hence my suggestion would be to visit your surgeon again with the reports and get the problem diagnosed. Later a visit to an experienced homeopath and starting with medicines would help in improving the sperm count as well as the quality of the sperm.
A detailed history is required for the same and hence it is not possible to prescribe online !!!!