Drezotomía en el tratamiento del dolor por desaferentización: revisión de resultados y análisis de factores predictores de éxito / DREZotomy in the treatment of deafferentation pain: review of results and analysis of predictive factors for success

Antecedentes y objetivos El tratamiento del dolor por desaferentización mediante drezotomía espinal es una opción terapéutica contrastada en la literatura. En los últimos años, la drezotomía ha visto relegado su empleo a un segundo plano debido a la eclosión de las terapias neuromoduladoras. Los objetivos de este estudio son demostrar que la drezotomía continúa siendo un tratamiento efectivo y seguro, y analizar aquellos factores predictores de éxito. Pacientes y métodos Se realizó un estudio retrospectivo de todos los pacientes tratados en nuestro servicio mediante drezotomía espinal desde 1998 hasta 2018. Se excluyeron los casos de drezotomía bulbar. Se emplearon la escala visual analógica (EVA) y la reducción de la medicación habitual como variables resultado, y se analizaron variables demográficas, clínicas y quirúrgicas como factores predictores de éxito. Resultados Un total de 27 pacientes (51,9% mujeres) de 53,7 años de edad media fueron tratados mediante drezotomía. La etiología principal del dolor fue por avulsión de plexo braquial (55,6%) seguida de causa tumoral (18,5%). El tiempo medio de evolución del dolor fue de 8,4 años con una intensidad media de 8,7 según la EVA, pese a que el 63% de los pacientes habían recibido tratamiento neuroestimulador previo. Durante el postoperatorio inmediato un 77,8% de los pacientes presentaron una reducción del 50% o más en la EVA. Tras un seguimiento medio de 22 meses posdrezotomía, permaneció una reducción de al menos el 50% en la EVA en el 59,3% de los pacientes (reducción media de 4,9 puntos) permitiendo una reducción del tratamiento analgésico habitual en el 70,4% de ellos. La drezotomía en la avulsión de plexo braquial presentó una tasa de éxito (93%) superior al resto de patologías (41,7%) de manera significativa (p = 0,001) (AU)

Background and objectives The treatment of deafferentation pain by spinal DREZotomy is a proven therapeutic option in the literature. In recent years, use of DREZotomy has been relegated to second place due to the emergence of neuromodulation therapies. The objectives of this study are to demonstrate that DREZotomy continues to be an effective and safe treatment and to analyse predictive factors for success. Patients and methods A retrospective study was conducted of all patients treated in our department with spinal DREZotomy from 1998 to 2018. Bulbar DREZotomy procedures were excluded. A visual analogue scale (VAS) and the reduction of routine medication were used as outcome variables. Demographic, clinical and operative variables were analysed as predictive factors for success. Results A total of 27 patients (51.9% female) with a mean age of 53.7 years underwent DREZotomy. The main cause of pain was brachial plexus injury (BPI) (55.6%) followed by neoplasms (18.5%). The mean time of pain evolution was 8.4 years with a mean intensity of 8.7 according to the VAS, even though 63% of the patients had previously received neurostimulation therapy. Favourable outcome (≥ 50% pain reduction in the VAS) was observed in 77.8% of patients during the postoperative period and remained in 59.3% of patients after 22 months average follow-up (mean reduction of 4.9 points). This allowed for a reduction in routine analgesic treatment in 70.4% of them. DREZotomy in BPI-related pain presented a significantly higher success rate (93%) than the other pathologies (41.7%) (p = .001). No association was observed between outcome and age, gender, DREZ technique, duration of pain or previous neurostimulation therapies. There were six neurological complications, four post-operative transient neurological deficits and two permanent deficits (AU)

DREZotomy in the treatment of deafferentation pain: review of results and analysis of predictive factors for success. / Drezotomía en el tratamiento del dolor por desaferentización: revisión de resultados y análisis de factores predictores de éxito.

BACKGROUND AND OBJECTIVES: The treatment of deafferentation pain by spinal DREZotomy is a proven therapeutic option in the literature. In recent years, use of DREZotomy has been relegated to second place due to the emergence of neuromodulation therapies. The objectives of this study are to demonstrate that DREZotomy continues to be an effective and safe treatment and to analyse predictive factors for success. PATIENTS AND METHODS: A retrospective study was conducted of all patients treated in our department with spinal DREZotomy from 1998 to 2018. Bulbar DREZotomy procedures were excluded. A visual analogue scale (VAS) and the reduction of routine medication were used as outcome variables. Demographic, clinical and operative variables were analysed as predictive factors for success. RESULTS: A total of 27 patients (51.9% female) with a mean age of 53.7 years underwent DREZotomy. The main cause of pain was brachial plexus injury (BPI) (55.6%) followed by neoplasms (18.5%). The mean time of pain evolution was 8.4 years with a mean intensity of 8.7 according to the VAS, even though 63% of the patients had previously received neurostimulation therapy. Favourable outcome (≥50% pain reduction in the VAS) was observed in 77.8% of patients during the postoperative period and remained in 59.3% of patients after 22 months average follow-up (mean reduction of 4.9 points). This allowed for a reduction in routine analgesic treatment in 70.4% of them. DREZotomy in BPI-related pain presented a significantly higher success rate (93%) than the other pathologies (41.7%) (p=.001). No association was observed between outcome and age, gender, DREZ technique, duration of pain or previous neurostimulation therapies. There were six neurological complications, four post-operative transient neurological deficits and two permanent deficits. CONCLUSION: Dorsal root entry zone surgery is effective and safe for treating patients with deafferentation pain, especially after brachial plexus injury. It can be considered an alternative treatment after failed neurostimulation techniques for pain control. However, its indication should be considered as the first therapeutic option after medical therapy failure due to its good long-term results.

Invasive treatment to control neuropathic pain / Tratamento invasivo para o controle da dor neuropática

ABSTRACT BACKGROUND AND OBJECTIVES: Distress, allied to neuropathic pain persistence and its refractory nature, often leads patients to accept invasive procedures. Neuropathic pain control is a major medical challenge requiring approaches and decisions especially based on effectiveness, risks and costs. This study aimed at reviewing these aspects related to major invasive procedures. CONTENTS: Major invasive procedures to control neuropathic pain are presented. Initially, classically reversible anesthetic blocks; then invasive neuromodulation techniques using electric current application and the magnetic field generated by it becomes a target to be stimulated, inhibited or modified in the nervous system (central, peripheral or autonomic); and, finally, ablative procedures including anesthetic methods administering neurolytic agents rather than anesthetics and neurosurgeries using different methods to injure the nervous system to control painful neuropathic discomfort. CONCLUSION: Patients eligible to invasive procedures to control neuropathic pain have, in addition to pain itself, a mixed distress including the collection of repeated delusions at every treatment failure. They have reserved prognosis with regard to total cure and, unfortunately, relieve obtained with invasive treatment in general does not reach persistent and high rates. In such adverse situation, these partial results of decreasing original pain intensity may be interpreted as acceptable, provided the impact on final quality of life is positive. Maybe, the rare exceptions are good results obtained with typical idiopathic/cryptogenic neuralgias ironically excluded from the stricter interpretation of the new pathophysiologic classification of neuropathic pains.

RESUMO JUSTFICATIVA E OBJETIVOS: O sofrimento aliado à persistência e refratariedade da dor neuropática frequentemente leva seu portador a aceitar tratamentos invasivos. O controle da dor neuropática representa um desafio médico importante necessitando adoção de condutas e decisões baseadas, principalmente, em efetividade, riscos e custos. O escopo deste estudo foi a revisão desses aspectos relacionados aos principais procedimentos invasivos CONTEÚDO: São apresentados os principais procedimentos invasivos utilizados para o controle da dor neuropática. Inicialmente, os bloqueios anestésicos, classicamente reversíveis; depois as técnicas de neuromodulação invasiva que utilizam a aplicação de corrente elétrica e o campo magnético por ela gerado em alvos a serem estimulados, inibidos ou modificados, no sistema nervoso (central, periférico ou autônomo); e, finalmente, os procedimentos ablativos que incluem os métodos anestésicos que administram agentes neurolíticos ao invés de anestésicos, e, as neurocirurgias que utilizam métodos diversos de produção de lesões no sistema nervoso para o controle do desconforto doloroso neuropático. CONCLUSÃO: Os pacientes que se apresentam como candidatos a receberem indicações de procedimentos invasivos para controle de dores neuropáticas, possuem além do inerente à própria dor, sofrimento misto, que inclui a coleção de desilusões reiteradas a cada insucesso de tratamento. Possuem prognóstico reservado no que tange a plena cura, e, infelizmente, o alívio obtido com o tratamento invasivo, em geral, não atinge taxas persistentes e elevadas. Nessa situação tão adversa esses resultados parciais de redução da intensidade da dor original possam ser interpretados como aceitáveis desde que o impacto na qualidade de vida final seja positivo. Talvez, as raras exceções, recaiam sobre os bons resultados obtidos com as neuralgias típicas, idiopáticas/criptogenéticas, ironicamente, excluídas da interpretação mais rígida da nova classificação fisiopatológica das dores neuropáticas.