[Chronic postsurgical pain]. / Douleurs chroniques postchirurgicales.

OBJECTIVES: Update reviewing of chronic postsurgical pain. DATA SOURCES: The following review is based on the English and French literature published in PubMed database between January 1998 and 2013. The research articles were made with following keywords alone or in combination: "chronic pain", "surgery", "postsurgical pain". These keywords were combined with "epidemiology", "incidence", "predictive factors" and "prevention". Study selection Publications were deemed relevant if they contained information about CPSP after 8 weeks post surgery. Animal publications were not included. Only randomized controlled studies were taken into consideration for the pharmacological prevention. DATA EXTRACTION: Data extracted were related to epidemiology, impact, predictive factors and prevention of CPSP. DATA SYNTHESIS: Epidemiology of CPSP is more recognized as it is experienced by 10-50% of individuals after classical operations. CPSP can be severe in about 5 to 10% of these patients. CPSP is a major public health problem still rarely diagnosed and treated. Twenty percent of patients consulting in a pain clinic have a CPSP. The frequency of neuropathic pain is important but the difference in the proportion to CPSP falls between 6-68% and depend on the type of surgery. Clinical risk factors and physiopathology of CPSP are subject of wide development. Human studies allowed better understanding of the neurophysiological as well psychological aspect of the development of CPSP. Finally, the possibility of pharmacological prevention of CPSP seems to have increased in the past years. Nevertheless, there are still many questions that need to be answers about the problem. We should clearly define the optimal characteristics of clinical and experimental studies as this will allow the better understanding of the prevention of CPSP. Anesthesiologists play a crucial role in this development. They are involved in all of the stages of the operative care of patients and play a decisive role in the evaluation of the risk, the development of a preventive strategy, and in the early detection and treatment of CPSP.

Neuroprotective gene therapy for Huntington's disease, using polymer-encapsulated cells engineered to secrete human ciliary neurotrophic factor: results of a phase I study.

Huntington's disease (HD) is a monogenic neurodegenerative disease that affects the efferent neurons of the striatum. The protracted evolution of the pathology over 15 to 20 years, after clinical onset in adulthood, underscores the potential of therapeutic tools that would aim at protecting striatal neurons. Proteins with neuroprotective effects in the adult brain have been identified, among them ciliary neurotrophic factor (CNTF), which protected striatal neurons in animal models of HD. Accordingly, we have carried out a phase I study evaluating the safety of intracerebral administration of this protein in subjects with HD, using a device formed by a semipermeable membrane encapsulating a BHK cell line engineered to synthesize CNTF. Six subjects with stage 1 or 2 HD had one capsule implanted into the right lateral ventricle; the capsule was retrieved and exchanged for a new one every 6 months, over a total period of 2 years. No sign of CNTF-induced toxicity was observed; however, depression occurred in three subjects after removal of the last capsule, which may have correlated with the lack of any future therapeutic option. All retrieved capsules were intact but contained variable numbers of surviving cells, and CNTF release was low in 13 of 24 cases. Improvements in electrophysiological results were observed, and were correlated with capsules releasing the largest amount of CNTF. This phase I study shows the safety, feasibility, and tolerability of this gene therapy procedure. Heterogeneous cell survival, however, stresses the need for improving the technique.