Prospective, observational, single-centre, non-interventional study aiming at reporting the prevalence of ATTRwt in patients with lumbar spinal stenosis (LSS).

The study will include patients that receive surgical management and treatment for LSS, and will consist in the prospective, longitudinal collection of peripheral blood, urine samples, tissue biopsies and clinical data. The results of the project could provide a future benefit for patients with the same condition by: i) identifying accessible and sensitive biomarkers for the identification of patients at risk for having an underlying ATTRwt; ii) optimizing the therapeutic strategies in an era of innovative but cost-intensive treatments; iii) provide the proof of principle for a regular follow-up of patients who eventually will become symptomatic for overt organ ATTRwt involvement; and iv) providing the rationale for future studies based on early access disease-modifying approaches.

Inclusion Criteria:

• Male and female ≥ 50 years-old with indication of surgery treatment according to local standards for Lumbar spinal stenosis (LSS) confirmed by MRI
• Availability of the baseline and follow-up annotations
• Informed consent will be obtained from the patient before any study related procedures

Exclusion Criteria:

• Previous diagnosis of amyloidosis

Prospective population of 100 patients undergoing LSS surgery.