I haven't found much about the Lachiondo surname (Spanish spell): It can be spelled in many different ways such as Latxiondo, Sasionso, or Sosiondo. All of those are spelled according to the Basque language. It means in English bramble or bramble patch...
I hope this information will help you.
Here you have some webs for further information: http://www.buber.net/Basque/Diaspora/http://www.euskalabizenak.com