In this prospective multi-centre double-blind trial the effect of the epiduroscopy will be examined in (approximately 300) adult patients with low back pain pain caused by failed back surgery syndrome (FBSS).

A small flexible fibreoptic catheter is inserted in sacral hiatus and the areas of concern can be visualized on the screen. Effective drugs like active enzyme: Hyaluronic acid and corticosteroids then can be injected through the same catheter.

With this method we can eliminate adhesions or scar tissue that may be pulling or irritating specific nerve roots.

Indicated for this procedure are patients with low back pain or sciatic patients who have not had a successful result with back surgery or spine surgery and have experienced continued pain after surgery: Failed back surgery syndrome (FBSS). Trial will compare groups of patients after fulfilment inclusion with Failed back surgery syndrome who will undergo interventional pain release procedure epiduroscopy. Elimination of adhesions, or scar tissue will be provided mechanically (grabbers, balloon techniques, by radiofrequency or laser) and with medical support (Hyaluronic acid and Depo-Medrol administration via epidural catheter).

The first group of patients enrolled in to the trial will undergo only mechanical lysis of epidural adhesions (grabbers, balloon techniques, by radiofrequency or laser).

The second group of patients enrolled in to the trial will undergo mechanical lysis of epidural adhesions together with epidural drug administration (Hyaluronic acid 150 IU and Depo-Medrol 80mg).

After first visit in ambulance patients will be about study informed. After agreement patient will be in to the study involved. Specific unique nine digits number will be assigned to each patient. Then patients will be randomized in to groups by special evaluated software created especially for this study. Patients will agree that about range of epiduroscopy (mechanical or combination of mechanical and drug administration) will be informed until the end of the study. This way will be patients blinded All acquired information will be noted in to the special anonymous protocol. Also patients will anonymously fulfill Oswestry Low Back Disability Questionnaire EQ-5D-5LQuestionnaire) .

Second examination will be provided after 6 months. Patients will be in the beginning introduced to doctor only by their unique number. Doctor will be blinded and he will not dispose with information about microinvasive procedure and will examine patient. Data which will be collected: (Visual analogue scale, dermatome where pain is radiating, global pain scale, changes in analgesics drugs consumption). All acquired information will be noted in to the special anonymous protocol. Also patients will anonymously fulfill Oswestry Low Back Disability Questionnaire EQ-5D-5LQuestionnaire) .

The third examination will be provided after 12 months same way. Patients will be in the beginning introduced to doctor only by their unique number. Doctor will be blinded and he will not dispose with information about microinvasive procedure and will examine patient. Data which will be collected: (Visual analogue scale, pain radiating dermatome, global pain scale, changes in analgesics drugs consumption). All acquired information will be noted in to the special anonymous protocol. Also patients will anonymously fulfill Oswestry Low Back Disability Questionnaire, EQ-5D-5LQuestionnaire).

Inclusion Criteria:

• Age of 18 years or older
• Written informed consent
• Patients with FBSS
• Magnetic resonance examination evidence of intervertebral disc herniation
• Permanent pain radiating to lower limbs despite previous periradicular therapy or caudal block
• Actual Magnetic resonance imaging: lesion without serious spinal stenosis, lesion without serious radicular compression, lesion without serious intervertebral disc herniation

Exclusion Criteria:

• Patients not capable of consenting
• Pregnant women or women of child-bearing potential
• Cauda equine syndrome