Wow 5 days away from your surgery , must be incredibly exciting!! From what I have read about Clavel I think you have made a good decision. I have avoided a 3 level lumbar fusion for quite a long time. Seems here in the USA they have a rubber stamp for fusion , and to me it's somewhat sad that Americans have to venture to Europe / pay cash when they have insurance here, just to have the hope and assurance as well as the confidence you need to have in your Dr. for a successful surgery.
Question: Did you go to Spain for a work up / exam with Clavel at an earlier date or was everything done by sending your records / scans etc. via e-mail? Looking forward to reading your success story on the 20th!!!! All the best.