-
If you have a recurrence from an anterior approach, then a posterior approach is indicated as the next way to repair it, for the reasons you mentioned (less scar tissue, so less risk of injury.)
In the US, this is usually done laparoscopically. That said, an open posterior approach is also an option, though with longer recovery time, usually.
Dr. Sheen can perhaps help you find someone in London or perhaps it is worth traveling.
By the way, erectile dysfunction is not directly affected by any hernia-related problems or complications. Any ED you may have is secondary (e.g., there is pain, so erection is painful and therefore difficult). Do not fear that ED will be maimed by a hernia repair.