Persistent neuropathic pain after inguinal herniorrhaphy depending on the procedure (open mesh v. laparoscopy): a propensity-matched analysis.

BACKGROUND: A greater incidence of persistent pain after inguinal herniorrhaphy is suspected with the open mesh procedure than with laparoscopy (transabdominal preperitoneal), but the involvement of neuropathy needs to be clarified. METHODS: We examined the cumulative incidence of neuropathic persistent pain, defined as self-report of pain at the surgical site with neuropathic aspects, within 6 months after surgery in 2 prospective subcohorts of a multicentre study. We compared open mesh with laparoscopy using different analysis, including a propensity-matched analysis with the propensity score built from a multivariable analysis using a generalized linear model. RESULTS: Considering the full patient sample (242 open mesh v. 126 laparoscopy), the raw odds ratio for neuropathic persistent pain after inguinal herniorrhaphy was 4.3. It reached 6.8 with the propensity-matched analysis conducted on pooled subgroups of 194 patients undergoing open mesh and 125 undergoing laparoscopy (95% confidence interval 1.5-30.4, p = 0.012). A risk factor analysis of these pooled subgroups revealed that history of peripheral neuropathy was an independent risk factor for persistent neuropathic pain, while older age was protective. CONCLUSION: We found a greater risk of persistent pain with open mesh than with laparoscopy that may be explained by direct or indirect lesion of nerve terminations. Strategies to identify and preserve nerve terminations with the open mesh procedure are needed.

CONTEXTE: On soupçonne que l'incidence de la douleur persistante à la suite d'une hernioplastie inguinale est plus élevée avec la mise en place d'un filet par voie ouverte qu'avec la laparoscopie (transabdominale prépéritonéale), mais encore faut-il clarifier le rôle de la neuropathie. MÉTHODES: Nous avons mesuré l'incidence cumulative de la douleur neuropathique persistante, décrite comme une douleur au site opératoire accompagnée d'éléments neuropathiques déclarés par le patient dans les 6 mois suivant la chirurgie, auprès de 2 sous-cohortes prospectives d'une étude multicentrique. Nous avons comparé la mise en place d'un filet par voie ouverte et la laparoscopie à l'aide de différentes analyses, dont une analyse avec appariement des scores de propension, les scores de propension découlant d'une analyse multivariée générée à partir d'un modèle linéaire généralisé. RÉSULTANTS: En tenant compte de tout l'échantillon de patients (242 soumis à la mise en place d'un filet par voie ouverte c. 126 soumis à la laparoscopie), le rapport des cotes brut pour la douleur neuropathique persistante après l'hernioplastie inguinale était de 4,3. Il a atteint 6,8 à l'analyse par appariement des scores de propension réalisée auprès de sous-groupes réunis de 194 patients soumis à la technique ouverte avec treillis et 125 soumis à la laparoscopie (intervalle de confiance à 95 % 1,5­30,4, p = 0,012). Une analyse des facteurs de risque pour ces sous-groupes réunis a révélé que des antécédents de neuropathie périphérique constituaient un facteur de risque indépendant à l'égard de la douleur neuropathique persistante, tandis que l'avancée en âge a conféré un effet protecteur. CONCLUSION: Nous avons observé un risque plus élevé de douleur persistante associée à la mise en place d'un filet par voie ouverte qu'avec la laparoscopie, ce qui pourrait s'expliquer par des lésions directes ou indirectes aux terminaisons nerveuses. Des stratégies s'imposent pour identifier et préserver les terminaisons nerveuses lors de la mise en place d'un filet par voie ouverte.

[Validation of the French version of the non-communicating children's pain checklist - postoperative version]. / Validation francophone de la grille d'évaluation de la douleur-déficience intellectuelle - version postopératoire.

PURPOSE: The aim of the study was to test the validity of a French language version of the Non-Communicating Children's Pain Checklist - Postoperative Version (NCCPC-PV): grille d'évaluation de la douleur-déficience intellectuelle (GED-DI). METHODS: We assessed the intensity of pain in 87 intellectually disabled surgical patients recruited in four Canadian and French hospitals in the pre- and post-operative settings using the GED-DI, a 100-mm visual analogue pain scale (VAS) and the Rosen sedation scale. The validity of the GED-DI was measured by the difference in scores between pre- and postoperative conditions. The checklist was made up of 30 items divided into seven subgroups. Items were rated from 0 to 3 for a total score ranging from 0 to 90 points. RESULTS: The mean (standard deviation) age of the patients was 17 (11) yr and the mean mental age 24.5 (24) months. The total GED-DI score was 6.1 (4.9) pre- and 13.4 (11.2) post-surgery (P < 0.001). All subgroups had a higher score after surgery (P < 0.001). The receiver operating characteristic (ROC) curves, comparing the absence of pain to mild pain scores and moderate to severe pain scores, showed a cutoff at 6 (mild pain) and 11 (moderate to severe pain). CONCLUSION: The French version of the NCCPC-PV can be used to assess pain in non-communicating patients with intellectual disabilities in a postoperative setting. It has good content validity, as the total pre-surgery score for the GED-DI was significantly lower than the postoperative score, and showed a good concurrent validity when compared to the VAS.

A prospective study of neuropathic pain induced by thoracotomy: incidence, clinical description, and diagnosis.

This study evaluated prospectively the incidence of neuropathic pain after thoracotomy, described its clinical characteristics, and delineated landmarks for its diagnosis in daily practice. We evaluated clinically painful symptoms and sensory deficits in 54 patients after lateral/posterolateral thoracotomy for broncho-pulmonary carcinoma with standardized surgical and analgesic procedures. At 2months, 49 patients suffered from non malignant thoracic pain, and at 6months 38 patients (loss to follow-up for 7) reported persisting pain. In 35 patients, painful symptoms and sensory deficits could be evaluated using a standardized clinical bedside procedure. According to the grading system proposed by Treede et al. [41], neuropathic pain was considered probable in 21 patients, while use of the DN4 questionnaire concluded that neuropathic pain was probable in 17 patients. The two diagnostic procedures provided similar conclusions in 16 patients. Morphine consumption during the early post-operative period (mean 111.3±30.8mg/day) and pain intensity (VAS: mean 5.71±2.1) were significantly higher in patients suffering from neuropathic pain than in other patients with pain (mean 80±21.4mg/day; VAS: mean 3.9±2.4). The clinical picture in most patients with neuropathic pain included electric shocks and severe multimodal hypoesthesia in the sensory area of 5th/6th intercostal nerves. Thus, our results indicate a minimal incidence of chronic post-thoracotomy pain at 70% and that of neuropathic pain at 29%, this latter being clinically suggested by a combination of certain symptoms and reinforced by the DN4 questionnaire when sensory deficit at scar is present.

Perioperative ketamine does not prevent chronic pain after thoracotomy.

Thoracotomy is often responsible for chronic pain, possibly of neuropathic origin. To confirm preclinical studies, the preventive effects of perioperative ketamine were tested in a randomized, double-blind, placebo-controlled clinical trial on persistent neuropathic pain after thoracotomy. Eighty-six patients scheduled for thoracotomy under standardised general anaesthesia were randomised to receive either ketamine (1 mg kg(-1) at the induction, 1 mg kg(-1) h(-1) during surgery, then 1 mg kg(-1) during 24 h; n=42) or normal saline (n=44). Postoperative analgesia included a single dose of intrapleural ropivacaine, intravenous paracetamol and nefopam, and patient-controlled intravenous morphine. Vital parameters and analgesia were recorded during the 48 first postoperative hours. Seventy-three patients were followed up. The patient's chest was examined 1-2 weeks, 6 weeks and 4 months after surgery. At the last two observations, spontaneous pain score over a one-week period (visual analogue scale), neuropathic pain score (NPSI), and intake of analgesics, were assessed. No drug affecting neuropathic pain (except opiates) was given during the follow-up. Two patients in each group were lost to follow-up after the 6 week visit. Ketamine improved immediate postoperative pain, but the groups were similar in terms of neuropathic pain and intake of analgesics, 6 weeks (NPSI score: ketamine: 1.25 [0-4.125]; placebo: 1 [0-4]) and 4 months after surgery. Thus, ketamine given in 24-h infusion failed to prevent chronic neuropathic pain after thoracotomy. Other perioperative preventive long-lasting treatments or techniques could be tested in this context.