Dorsal Root Ganglion Stimulation for Chronic Postoperative Pain Following Thoracic Surgery: A Pilot Study.

OBJECTIVES: Post-thoracotomy pain syndrome (PTPS) is defined as persistent pain following a thoracotomy and has an incidence of 21-61%. Dorsal root ganglion stimulation (DRG-S) is a form of neuromodulation that modulates pain signal transmission to the spinal cord. The aims of this study were to investigate the efficacy of DRG-S for the management of PTPS and to assess the role of thoracic paravertebral blocks (t-PVB) as a tool for prediction of success of DRG-S. MATERIALS AND METHODS: In this prospective study, we included all patients undergoing thoracic surgery, with PTPS not responding to pharmacotherapy and treated with DRG-S from September 2018 to February 2019. t-PVB followed by a percutaneous DRG-S trial was performed on all patients. Pain intensity was assessed through a numeric rating scale (NRS) and Douleur Neuropathique en 4 Questions (DN4) at baseline, post-trial, at 14 days, 90 days, and at one year after DRG-S implantation. Data summarized as continuous variables were expressed as means and standard deviations (SDs), and categorical variables were expressed as raw numbers and percentages. RESULTS: Four patients out of 51 who underwent thoracic surgery at our institution surveyed were included (mean age ± SD, 56 ± 16 years old). Mean NRS and DN4 were, respectively, 7.2 ± 0.96 SD and 8.2 ± 0.5 SD at baseline, 2.5 ± 0.6 SD and 3.2 ± 0.5 SD after t-PVB, 2.2 ± 0.5 SD and 2.2 ± 0.5 SD at 14 days, 90 days, and at one year after DRG-S implantation. No complications or side effects were reported. CONCLUSIONS: Our preliminary results show that DRG-S is an effective therapy for PTPS after thoracic surgery. In addition, thoracic paravertebral blocks performed prior to DRG-S correlated with a positive outcome with treatment.

Effects of anaesthesia and analgesia on long-term outcome after total knee replacement: A prospective, observational, multicentre study.

BACKGROUND: Perioperative regional anaesthesia may protect from persistent postsurgical pain (PPSP) and improve outcome after total knee arthroplasty (TKA). OBJECTIVES: Aim of this study was to evaluate the impact of regional anaesthesia on PPSP and long-term functional outcome after TKA. DESIGN: A web-based prospective observational registry. SETTING: Five Italian Private and University Hospitals from 2012 to 2015. PATIENTS: Undergoing primary unilateral TKA, aged more than 18 years, informed consent, American Society of Anesthesiologists (ASA) physical status classes 1 to 3, no previous knee surgery. INTERVENTION(S): Personal data (age, sex, BMI and ASA class), preoperative pain assessed by numerical rating scale (NRS) score, and risk factors for PPSP were registered preoperatively. Data on anaesthetic and analgesic techniques were collected. Postoperative pain (NRS), analgesic consumption, major complications and patient satisfaction were registered up to the time of discharge. PPSP was assessed by a blinded investigator during a phone call after 1, 3 and 6 months, together with patient satisfaction, quality of life (QOL) and walking ability. MAIN OUTCOME MEASURES: Experience of PPSP according to the type of peri-operative analgesia. RESULTS: Five hundred sixty-three patients completed the follow-up. At 6 months, 21.6% of patients experienced PPSP, whereas autonomy was improved only in 56.3%; QOL was worsened or unchanged in 30.7% of patients and improved in 69.3%. Patients receiving continuous regional anaesthesia (epidural or peripheral nerve block) showed a lower NRS through the whole peri-operative period up to 1 month compared with both single shot peripheral nerve block and those who did not receive any type of regional anaesthesia. No difference was found between these latter two groups. Differences in PPSP at 3 or 6 months were not significantly affected by the type of anaesthesia or postoperative analgesia. A higher NRS score at 1 month, younger age, history of anxiety or depression, pro-inflammatory status, higher BMI and a lower ASA physical status were associated with a higher incidence of PPSP and worsened QOL at 6 months. CONCLUSION: Continuous regional anaesthesia provides analgesic benefit for up to 1 month after surgery, but did not influence PPSP at 6 months. Better pain control at 1 month was associated with reduced PPSP. Patients with higher expectations from surgery, enhanced basal inflammation and a pessimistic outlook are more prone to develop PPSP. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02147730.

Intraarticular STP Radiofrequency for Painful Osteoarthritis in the Knee: A Retrospective Single Center Analysis.

OBJECTIVE: Osteoarthritis (OA) is the most common cause of chronic knee pain, often a debilitating condition that can cause a significant reduction in functional capacity. Radiofrequency is a form of neuromodulation that modulates pain signal transmission and has become progressively more common as a treatment for knee pain. This retrospective study aims to evaluate the efficacy of intraarticular radiofrequency in patients with chronic knee OA pain. MATERIALS AND METHODS: In this retrospective study, we included 129 patients undergoing intraarticular pulsed radiofrequency using the Poisson curve for energy distribution (Sluijter-Teixeira Poisson radiofrequency) (STP) from March 2018 to November 2019. Knee osteoarthritis severity was assessed prior to the procedure using the Lequesne Index, classifying patients into six groups based on level of severity. Pain intensity was assessed through a 10-cm visual analog scale (VAS), and level of patient satisfaction was assessed through a questionnaire. RESULTS: In the sample, pain reduction as measured by VAS compared to baseline prior to the procedure was statistically significant immediately following the procedure, at 30 days and at 90 days (p<0.001); this difference was less significant at 180 days (p<0.005). Efficacy in patients with moderate to severe disability was considerably greater than in patients with very severe to extremely severe disability. 57.36% reported that they were very satisfied, 29.46% satisfied, 9.3% neither satisfied nor dissatisfied, 2.33% dissatisfied, and 1.55% very dissatisfied. CONCLUSION: Our results suggest that STP radiofrequency may be a safe and effective procedure for knee OA, able to significantly reduce VAS scores at 1 month and 3 months compared to baseline. Based on our results, a key factor to consider when treating knee OA with STP radiofrequency is that it is more effective among patients with a lower level of disability. Due to the retrospective observational study design, prospective longitudinal investigation is required to further support the recommendation of STP radiofrequency for knee OA.

Chronic Chest Pain Control after Trans-Thoracic Biopsy in Mediastinal Lymphomas.

Chest pain following a trans-thoracic biopsy often has multiple etiologies, especially in patients with lymphomas. Pathological neuronal mechanisms integrate with an overproduction of IL-6, TNF-α, IL1-ß by macrophages and monocytes, which amplifies inflammation and pain. In consideration of this complex pathogenesis, international guidelines recommend diversified analgesia protocols: thoracic epidural, paravertebral block, and systemic administration of opioids. This study reports an attempt to reduce chest pain and prevent chronic pain in 51 patients undergoing trans-thoracic biopsy for mediastinal lymphoma. The entity of pain, measured 72nd hour after biopsy by the Numerical Rating Scale (NRS), was compared with that seen at a 6th month checkpoint in 46 patients. The pain decreased in all cases. At the 6th month checkpoint, among 31 opioid-treated patients, none of the 16 patients with NRS < 6 within the 72nd hour post biopsy had developed chronic chest pain, while 8 of the 15 with higher values did (p < 0.01). Of 10 patients undergoing thoracotomy and treated with opioids, eight had a NRS of no more than 2, of which six had no chronic pain. Of the twenty-one patients who underwent VATS biopsy and were treated with opioids, fifteen had NRS no greater than 2, of which ten had no chronic pain. Subgroups of patients biopsied under mediastinotomy or video-assisted thoracoscopic surgery (VATS) and treated with thoracic epidural analgesia (TEA) or PVB were too small for such analysis.