Gelified Radiopaque Ethanol (Absolute Gel) in Cervical Disc Herniation: an Observational Study in Routine Clinical Practice (GENESIS) (GENESIS)

Adults with cervical disc herniation and chronic discogenic neck pain who receive, or have already received, intradiscal radiopaque gelified ethanol (Absolute Gel) as part of routine clinical practice, based exclusively on the decision of the treating physician. The single cohort includes both retrospectively and prospectively enrolled participants. No treatment is assigned by the study.

CE-marked Class III medical device used within its approved indications as part of standard clinical care. Intradiscal injection of radiopaque gelified ethanol at the cervical level, performed under fluoroscopic guidance through an antero-lateral approach with local anaesthesia, typically 0.3 to 0.4 mL per disc. The study does not assign, impose or modify the treatment, the technique or the peri-procedural management; it records the procedure as performed in routine practice.

• Radiopaque gelified ethanol
• Intradiscal chemonucleolysis with gelified ethanol

Neck pain intensity is measured with the Visual Analogue Scale (VAS), a 0 to 10 scale where 0 = no pain and 10 = worst imaginable pain. Lower scores indicate less pain. The measure is the proportion of participants whose VAS score at 1 month is reduced by at least 30% compared with baseline, reported with exact 95% binomial confidence intervals. Descriptive only; no hypothesis testing is performed.

Continuous change from baseline in VAS score (0 to 10; lower scores indicate less pain), summarised with mean, standard deviation, median, interquartile range and range. Descriptive only.

VAS scores (0 to 10; lower scores indicate less pain) and changes from baseline at each scheduled follow-up, summarised descriptively.

Proportion of participants achieving a reduction of at least 50% in VAS score compared with baseline, reported descriptively as an indicator of a more pronounced clinical response.

Self-reported perception of overall change assessed with the PGIC scale (7 categories, from "very much improved" to "very much worse"; lower scores indicate greater perceived improvement). Reported as frequency distributions; the proportion of participants reporting "much improved" or "very much improved" may be reported with 95% confidence intervals, for descriptive purposes only.

CNFDS is a validated 15-item questionnaire assessing neck-related functional disability, with a total score from 0 to 30; higher scores indicate greater disability. Changes from baseline are summarised descriptively.

NPAD is a validated 20-item questionnaire assessing neck pain and related disability, with a total score from 0 to 100; higher scores indicate greater pain and disability. Changes from baseline are summarised descriptively.

Qualitative and quantitative documentation of analgesic, NSAID and corticosteroid use (type, dose, duration, indication) recorded during routine follow-up and compared with pre-treatment use. Descriptive only.

Incidence, type, severity, outcome and relatedness (device, procedure, other) of adverse events (AE), serious adverse events (SAE) and serious adverse device effects (SADE), collected within predefined windows: 0-24 hours, day 1-30, day 31-90, day 91-365 and beyond 365 days up to 48 months.

Predefined AESIs: discitis/osteomyelitis; procedure-related meningitis; worsening radiculopathy with new or progressive neurological deficit.

Surgical re-intervention at the treated disc level, recorded as a clinically relevant marker of treatment failure or complication.

Device deficiencies and malfunctions documented and reported in accordance with ISO 14155 and Regulation (EU) 2017/745.

Descriptive reporting of morphological disc findings (treated level, herniation morphology, Pfirrmann grade, nerve root compression, other structural findings). No imaging is mandated by the study; MRI data are collected only if performed as part of routine clinical care.