Efectividad de la respuesta al tratamiento intervencionista en la unidad del dolor sobre la radiculalgia secundaria a hernia discal

Abstract

Patients with radicular pain secondary to herniated disk (HD) and not responding to conservative treatment would be candidates to surgery because of limited pain control. Hypothesis: Epidural administration of local anaesthetic and depot corticosteroid changes and/or promotes the recovery of patients with radicular pain secondary to HD, while diminishing pain and avoiding surgery. Main objective: to evaluate the therapeutic efficacy of the minimally invasive interventional treatment administered by epidural route through assessment on the Numeric Pain Rate Scale (NPRS) at the end of the 6 months follow-up period; treatment success was defined as a NPRS score ≤3 and not having had surgery. Secondary objectives: 1. To measure the analgesic effectiveness with the NPRS at 1, 3, and 6 months after treatment. 2. To quantitate the number of patients having had surgery within a 1 year follow-up. 3. To assess other parameters that may influence the process in order to define predictive factors for treatment response: a. Demographic factors and duration of pain before treatment. b. NPRS score before treatment. c. HD anatomical characteristics: axial disposition, location, extrusion, migration and radicular involvement. d. Presence of structural abnormalities of the spine. Patients and Method. An ambispective study was conducted with a final cohort of 146 patients with radicular pain secondary to HD and limited response to conservative treatment. The interventional treatment was performed after clinical assessment and radiographic documentation, and consisted of the epidural administration of 0.2% ropivacaine and depot corticosteroid (triamcinolone) according to protocol. The following data were recorded: duration of pain before treatment, pain intensity according to NPRS at baseline, and prospectively at 1, 3 and 6 months, and surgery within 1 year of follow-up. CT/MRI radiographic findings by were retrospectively analysed: HD axial anatomy, extrusion, and migration, and whether there was radicular and structural involvement of the spine. Statistical analysis: a descriptive study of the variables was performed. The occurrence of an association between qualitative variables was assessed by a Chi-squared test or a Fisher’s exact test depending on the application conditions. Linear correlation between quantitative variables was evaluated by a Pearson correlation test. Comparison of continuous variables depending on a qualitative variable was performed with a Student t-test for independent groups, a Student t-test for paired data, or with an ANOVA test according to the characteristics of the dependent variable. P values <0.05 were regarded as significant. Multivariate analyses were performed using logistic regression and classification trees based on a recursive partitioning analysis, using the Classification and Regression Tree model. The statistical analysis was carried out with the SPSS 17.0 software. Results and Conclusions: 1. Considering as overall successful outcome of the treatment that the patient did not require surgery and had a NPRS score ≤3 at 6 months, the treatment was successful in 69.9% of the patients. 2. The maximal effectiveness of the treatment was at 1 month, with mean decrease of 3.56% on the NPRS. 3. Twenty four patients (16.45%) underwent surgery since the treatment initiation and before completion of the 1 year follow-up period. 4. The following were found to be predictive factors associated to an inadequate response to the treatment: being male, <34 years of age, NPRS ≥ 8 at baseline, as well as certain HD anatomical features such as central location and the occurrence of canal stenosis. Lack of response at 1 month would differentiate those patients with worse prognosis.

Date of Award	3 Feb 2016
Original language	Spanish
Supervisor	Francisco Javier Leon Vintro (Director) & Elena Català Puigbó (Director)