There are only two natural routes for the sperm to reach the egg: the two fallopian tubes. If one is absent and the other one is blocked, than it is not possible. “Terminal large hydrosalpinx” suggests a dilated tube which has most probably lost its function. The surgical correction (re-opening the tube) is relatively simple, however it is less likely it would retain proper tube function (transfer of sperms and embryo). If you are planning to conceive, it is advisable to treat or remove large hydrosalpinx as it may reduce the chance of implantation and successful pregnancy. However if this is done you will need IVF treatment.