The CADISS® System, Chemically Assisted mechanical DISSection, is intended for the selective detachment of pathological tissue layers and/or fibrotic tissues in various surgical procedures without using cutting instruments. It is based on the property of the drug mesna (Sodium 2-mercaptoethane sulfonate) to cleave the disulfide bonds responsible for the adherence of pathological tissues and for the strength of fibrosis. Revision spine surgery is more difficult than primary surgery because of the development of fibrosis and scar tissues since the first operation. Fibrosis may develop in the spinal canal and will adhere strongly to the dura mater and to the nerve roots. This study is a prospective, multi-sites, open label, single cohort clinical trial evaluating the use of CADISS medical devices to facilitate dissection of epidural fibrosis in patients who undergo a revision in spine surgery after at least one year.

Inclusion Criteria:

• ≥ 18 years old, weight > 30 Kg
• Eligible for Spine revision surgery, at least one year after primary surgery
• Agree to participate and sign the informed consent

The age and weight of patient are defined according to the instruction for use of the CADISS System currently on the EU market.

Exclusion Criteria:

• < 18 years old
• Weight ≤ 30 kg
• Primary surgery
• Known hypersensibility to mesna
• Patient is pregnant, breastfeeding or has wish of pregnancy during the study.
• Unable to sign the informed consent
• Participation in any study involving an investigational drug or device within the past 3 Months.
• Individuals under tutorship or trusteeship.