Adjuvant administration of hypertonic saline in lumbar epidural intervention may be associated with successful response in patients with probable neuropathic radicular pain Screened by Douleur Neuropathique 4.

Background: Chronic lumbar radicular pain often accompanies neuropathic pain. The treatment may follow a screening for probable neuropathic pain rather than the definitive diagnosis, which is often difficult in daily practice. However, interventional management may have limited effects on symptoms in patients with neuropathic radicular pain refractory to conservative treatments. The purpose of this study is to evaluate the factors associated with successful responses after lumbar epidural intervention in patients with chronic lumbar neuropathic radicular pain determined by Douleur Neuropathique 4 (DN4). Methods: We retrospectively reviewed 221 chronic lumbar radicular pain patients using a DN4 questionnaire prior to the epidural interventional procedure. The patients were divided into two groups according to the DN4 questionnaire: <4-point DN4 and ≥4 DN4. The numerical rating scale (NRS) for pain intensity, changes in physical functional status, and the use of pain medication were obtained before and 1 month after the procedure. Successful responder was defined based on robust combination of outcome parameters. The factors associated with successful response were analyzed using univariate and multivariate regression. Results: We found 170 (76.9%) patients with DN4 <4 and 51 (23.1%) with a score ≥4. Among the total 221 patients, 129 (58.4%) were successful responders and 92 (41.6%) were non-responders regardless of DN4 score. We observed a significantly lower proportion of successful responders among patients with a DN4 score ≥4 (22, 43.1%) than patients with a score <4 (107, 62.9%) (P=0.012). After adjusting in multivariate regression analysis, the DN4 score was independently associated with response after lumbar epidural intervention (odds ratio [OR]=0.838; 95% confidence interval [CI]=0.718-0.978; P=0.025). In subgroup logistic regression analysis according to the DN4 score, adjuvant administration of hypertonic saline during epidural interventions in patients with a DN4 score ≥4 (OR=3.71; CI=1.142-12.457; P=0.029) was associated with the success of the lumbar epidural procedure at 1 month. Conclusion: The adjuvant use of hypertonic saline in lumbar epidural interventions may be effective at least 1 month after the intervention in patients with probable neuropathic lumbar radicular pain ≥4 using the DN4.

Factors associated with Successful Responses to Ganglion Impar Block: A Retrospective Study.

Background: The ganglion impar (ganglion of Walther) block has been used to manage coccygeal and perineal (perianal and genital) pain due to both benign and malignant causes. However, the factors associated with successful responses to ganglion impar block are unknown. Therefore, in the present study, we aimed to identify the independent factors associated with successful responses to ganglion impar block in patients with chronic pain in coccygeal and perineal regions. Methods: From January 2008 to December 2017, we performed a retrospective review of 106 patients who underwent ganglion impar block. Patients were considered successful responders if they reported a decrease of more than 50% or 4 points on the 11-point (0 = no pain and 10 = worst possible pain) numerical rating scale 1 month after the procedure, while others were considered non-responders. Logistic regression analysis was performed to identify factors independently associated with successful responses at 1 month after the procedure. Results: Multivariable logistic regression analysis showed that cancer-related causes were significantly associated with successful responses at 1 month after ganglion impar block (odds ratio = 2.60, 95% confidence interval = 1.05 to 6.43, P = 0.038). Conclusion: Ganglion impar block may be more effective in cancer-related pain than pain due to benign causes.

The preventive effect of resiniferatoxin on the development of cold hypersensitivity induced by spinal nerve ligation: involvement of TRPM8.

BACKGROUND: Resiniferatoxin (RTX) is a potent analog of capsaicin and activates transient receptor potential (TRP) vanilloid type (TRPV) 1. In the current study, we investigated the preventive effect of perineural RTX on the development of cold hypersensitivity induced by spinal nerve ligation (SNL) in rats. Furthermore, we examined the association between the expression level of TRPV1, TRP ankyrin type (TRPA) 1 and TRP melastatin type (TRPM) 8 in the dorsal root ganglion (DRG) and cold hypersensitivity after SNL. RESULTS: RTX pretreatment prevented the development of SNL-induced hypersensitivity to mechanical, thermal, and cold stimuli. Western blot analysis 4 weeks after RTX pretreatment showed that RTX pretreatment decreased the protein expression level of SNL-induced TRPM8, but not TRPV1 or TRPA1, in the DRG of SNL rats. Immunofluorescent analysis revealed that up-regulated TRPM8-stained neurons after SNL co-localized with neurofilament 200-positive neurons located in the DRG. CONCLUSIONS: Pretreatment with perineural RTX significantly inhibits SNL-induced mechanical, thermal, and cold hypersensitivity. The antinociceptive effect of perineural RTX, especially on cold hypersensitivity, may be related to the suppression of TRPM8 expression in DRG.

Treatment of chronic lumbosacral radicular pain using adjuvant pulsed radiofrequency: a randomized controlled study.

OBJECTIVES: The objective of this study was to determine the effects of combining pulsed radiofrequency (PRF) treatment and transforaminal epidural injection (TFEI) to treat patients with chronic refractory lumbar radicular pain caused by lumbar spinal stenosis. STUDY DESIGN: Randomized control trial. SETTINGS: Interventional pain management practice. METHOD: Sixty-two patients were assigned to the study groups (PRF group = 31; control group = 31). Under fluoroscopic guidance, the RF needle was positioned close to the lumbar dorsal root ganglion. The PRF group received 3 cycles of PRF treatment, and sensory stimulation without RF lesioning was applied to the control group. After PRF or sham lesioning, a local anesthetic with steroid was injected. The primary outcome of a successful response was defined as: 1) ≥50% or 4-point pain reduction in the numerical rating scale (NRS) without an increase in the Oswestry disability index (ODI) or medication quantification scale (MQS), or mean score <4 in the global perceived effect (GPE) scale; or 2) ≥30% or 2-point pain reduction in NRS with a simultaneous decrease in ODI, MQS, or ≥6 points in the GPE scale. RESULT: The number of patients with successful treatment results was higher in the PRF group at 2 months (P = 0.032) and 3 months (P = 0.018). No significant differences were observed in terms of the secondary outcome variables between the 2 groups. CONCLUSION: The TFEI provided significant short-term pain relief and PRF can be applied in conjunction with TFEI to achieve higher treatment efficacy compared with TFEI alone.

Perineural pretreatment of bee venom attenuated the development of allodynia in the spinal nerve ligation injured neuropathic pain model; an experimental study.

BACKGROUND: Diluted bee venom (BV) is known to have anti-nociceptive and anti-inflammatory effects. We therefore assessed whether perineural bee venom pretreatment could attenuate the development of neuropathic pain in the spinal nerve ligation injured animal model. METHODS: Neuropathic pain was surgically induced in 30 male Sprague Dawley rats by ligation of the L5 and L6 spinal nerves, with 10 rats each treated with saline and 0.05 and 0.1 mg BV. Behavioral testing for mechanical, cold, and thermal allodynia was conducted on postoperative days 3 to 29. Three rats in each group and 9 sham operated rats were sacrificed on day 9, and the expression of transient receptor potential vanilloid type 1 (TRPV1), ankyrin type 1 (TRPA1), and melastatin type 8 (TRPM8) receptors in the ipsilateral L5 dorsal root ganglion was analyzed. RESULTS: The perineural administration of BV to the spinal nerves attenuated the development of mechanical, thermal, and cold allodynia, and the BV pretreatment reduced the expression of TRPV1, TRPA1, TRPM8 and c - Fos in the ipsilateral dorsal root ganglion. CONCLUSION: The current study demonstrates that the perineural pretreatment with diluted bee venom before the induction of spinal nerve ligation significantly suppresses the development of neuropathic pain. Furthermore, this bee venom induced suppression was strongly related with the involvement of transient receptor potential family members.

Adenosine triphosphate-sensitive potassium channel blockers attenuate the antiallodynic effect of R-PIA in neuropathic rats.

BACKGROUND: Nerve injury can generate neuropathic pain. The accompanying mechanical allodynia may be reduced by the intrathecal administration of adenosine. The neuroprotective effects of adenosine are mediated by the adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channel. We assessed the relationship between the adenosine A1 receptor agonist, N6-(R)-phenylisopropyl adenosine (R-PIA), and K(ATP) channels to determine whether the antiallodynic effects of R-PIA are also mediated through K(ATP) channels in a rat nerve ligation injury model of neuropathic pain. METHODS: Mechanical allodynia was induced by tight ligation of the left lumbar fifth and sixth spinal nerves. Mechanical allodynia in the left hindpaw was evaluated using von Frey filaments to measure withdrawal thresholds. R-PIA (0.5, 1, or 2 µg) was administered intrathecally to induce antiallodynia. We assessed whether pretreatment with the K(ATP) channel blockers glibenclamide or 5-hydroxydecanoate reversed the antiallodynic effect of R-PIA. Also, we evaluated whether diazoxide, a K(ATP) channel opener, had an antiallodynic effect and promoted the antiallodynic effect of R-PIA. Lastly, we investigated whether the voltage-activated K channel blocker 4-aminopyridine attenuated the effect of R-PIA. RESULTS: Intrathecal R-PIA produced maximal antiallodynia at 2 µg (P < 0.05). Intrathecal pretreatment with glibenclamide and intraperitoneal pretreatment 5-hydroxydecanoate significantly reduced the antiallodynic effect of R-PIA. Diazoxide produced an antiallodynic effect and also enhanced the antiallodynic action of R-PIA. 4-Aminopyridine had no effect on the antiallodynic action of R-PIA. CONCLUSIONS: The antiallodynic effects of adenosine A1 receptor stimulation may be related to K(ATP) channel activity in a rat model of nerve ligation injury.

Effects of Curcumin Treatment in a Diabetic Neuropathic Pain Model of Rats: Involvement of c-Jun N-Terminal Kinase Located in the Astrocytes and Neurons of the Dorsal Root Ganglion.

Curcumin (diferuloylmethane) is a major component of turmeric, which is isolated from the rhizomes of Curcuma longa L. from the family Zingiberaceae. It is used as a dietary pigment for curry and in traditional Indian medicine for its anti-inflammatory and attenuating pain effects. This study aimed to evaluate the beneficial effects of curcumin in a rat model of diabetic neuropathic pain. Additionally, we investigated the involvement of the phosphorylated form of c-Jun N-terminal kinase (pJNK) located in the neurons and astrocytes of the dorsal root ganglion (DRG). To induce diabetic neuropathic pain in rats, 50 mg/kg of streptozotocin (STZ) was intraperitoneally injected. After 4 weeks, rats were administered the vehicle, 10 mg/kg/day curcumin, or 50 mg/kg/day curcumin orally for 4 consecutive weeks. One day after the final drug administration, we performed behavioral tests to measure responses of rats to mechanical, heat, cold, and acetone-induced cold stimuli. After behavioral tests, pJNK expression in the DRG was evaluated using western blot assay and immunohistochemistry. Curcumin treatment for 4 consecutive weeks in STZ-induced diabetic neuropathic pain rats improved behavioral responses to mechanical, cold, and thermal stimuli. Increased pJNK expression in the astrocytes and neurons of the DRG in STZ-induced diabetic neuropathic pain rats was reduced by curcumin treatment for 4 consecutive weeks. We suggest that curcumin can be an option for the treatment of diabetes-related neuropathic pain, and one of the mechanisms that underlie the action of curcumin may involve pJNK expression in the astrocytes and neurons of the DRG.

The Association between Herpes Zoster and Increased Cancer Risk: A Nationwide Population-Based Matched Control Study.

BACKGROUND: Herpes zoster (HZ) is strongly associated with decreased immune function, a factor of cancer development. Previous studies suggested inconsistent results regarding the association between HZ and increased cancer risk. We aimed to analyze the association between HZ and specific cancer risk. METHODS: Of 134,454 patients diagnosed with HZ between 2002 and 2015, 81,993 HZ patients were matched 1:1 with non-HZ individuals by age, sex, and Charlson comorbidity index. Both groups were examined at 1, 3, and 5 years for cancer diagnosis. A Cox proportional hazard regression model was used to estimate cancer risk in both groups. The postherpetic neuralgia (PHN) and non-HZ groups were compared for specific cancer risk. RESULTS: The HZ group showed a slightly decreased overall cancer risk compared with the non-HZ group (hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.90-0.97, p = 0.002). The HRs for specific cancer risk were 0.41 (95% CI, 0.33-0.50, p < 0.001); 0.86 (95% CI, 0.81-0.91, p < 0.001); 0.87 (95% CI, 0.78-0.97, p = 0.014); 0.80 (95% CI 0.73-0.87, p < 0.001); 1.20 (95% CI, 1.07-1.34, p = 0.001); and 1.66 (95% CI, 1.35-2.03, p < 0.001) for cancers of the lips, mouth, and pharynx; digestive system; respiratory system; unknown secondary and unspecified sites; thyroid and endocrine glands; and lymphoid and hematopoietic systems, respectively. The HZ with PHN group showed higher HR for specific cancer risk, such as lymphoid and hematopoietic systems (95% CI, 1.27-2.39, p < 0.001). CONCLUSION: HZ was associated with increased or decreased incidence of specific cancers. PHN further increased the risk of developing certain cancers in HZ patients.

Factors associated with successful response to neurolytic celiac plexus block in patients with upper abdominal cancer-related pain: a retrospective study.

BACKGROUND: Prior studies have reported that 40%-90% of the patients with celiac plexus-mediated visceral pain benefit from the neurolytic celiac plexus block (NCPB), but the predictive factors of response to NCPB have not been evaluated extensively. This study aimed to identify the factors associated with the immediate analgesic effectiveness of NCPB in patients with intractable upper abdominal cancer-related pain. METHODS: A retrospective review was performed of 513 patients who underwent NCPB for upper abdominal cancer-related pain. Response to the procedure was defined as (1) a decrease of ≥ 50% or ≥ 4 points on the numerical rating scale (NRS) in pain intensity from the baseline without an increase in opioid requirement, or (2) a decrease of ≥ 30% or ≥ 2 points on the NRS from the baseline with simultaneously reduced opioid consumption after NCPB. Logistic regression analysis was performed to determine the factors associated with successful responses to NCPB. RESULTS: Among the 513 patients included in the analysis, 255 (49.8%) and 258 (50.2%) patients were in the non-responder and responder group after NCPB, respectively. Multivariable logistic regression analysis showed that diabetes (odds ratio [OR] = 0.644, P = 0.035), history of upper abdominal surgery (OR = 0.691, P = 0.040), and celiac metastasis (OR = 1.496, P = 0.039) were the independent factors associated with response to NCPB. CONCLUSIONS: Celiac plexus metastases, absence of diabetes, and absence of prior upper abdominal surgery may be independently associated with better response to NCPB for upper abdominal cancer-related pain.

Predictors Associated with Outcomes of Epidural Blood Patch in Patients with Spontaneous Intracranial Hypotension.

An autologous epidural blood patch (EBP) is a mainstay of treatment in patients with spontaneous intracranial hypotension (SIH). EBP, however, is less effective for SIH than post-dural puncture headaches. Therefore, patients with SIH frequently require an additional EBP. The aim of this study was to identify factors associated with poor response to EBP. This single-center retrospective observational study used the institutional registry records of 321 patients who underwent EBP between September 2001 and March 2016. Patients were divided into two groups, a poor responder group, consisting of patients who underwent EBP at least three times or more, and a good responder group of patients who experienced sufficient symptom relief after two or fewer EBP. The demographic characteristics, clinical features, radiologic findings, procedural data, and laboratory data were analyzed. Univariate analysis showed that the neutrophil-to-lymphocyte ratio (NLR; p = 0.004) and platelet-to-lymphocyte ratio (p = 0.015) were significantly lower in poor than in good responders. Multivariate analysis found that NLR was the only independent factor associated with a poor response (odds ratio = 0.720; p = 0.008). These findings indicate that a low NLR was associated with three or more EBP administrations for the sufficient improvement of symptoms in patients with SIH.

Association between Postoperative Opioid Requirements and the Duration of Smoking Cessation in Male Smokers after Laparoscopic Distal Gastrectomy with Gastroduodenostomy.

Smoking is clinically associated with high postoperative pain scores and increased perioperative analgesic requirements. However, the association between the duration of smoking cessation and postoperative opioid requirements remains unclear. Therefore, this study aimed to evaluate the association between the duration of smoking cessation and postoperative opioid requirements. We retrospectively analyzed the data of 144 male patients who received intravenous patient-controlled analgesia (IV PCA) after laparoscopic distal gastrectomy with gastroduodenostomy. All patients were divided into three groups: G0, nonsmoker; G1, smoker who quit smoking within 1 month preoperatively; G2, smoker who quit smoking over 1 month preoperatively. Analgesic use, pain intensity, and IV PCA side effects were assessed up to postoperative day 2. As the duration of smoking cessation increased, the amount of postoperative opioid consumption decreased (ß = -0.08; 95% confidence interval (CI), -0.11 to -0.04; P < 0.001). The total postoperative opioid requirements in G1 were significantly higher than those in G0 and G2 (G0, 75.5 ± 15.9 mg; G1, 94.6 ± 20.5 mg; and G2, 79.9 ± 19.4 mg (P < 0.001)). A multivariate regression analysis revealed that G1 was independently associated with increased postoperative opioid requirements (ß = 12.80; 95% CI, 5.81-19.80; P < 0.001). Consequently, male patients who had ceased smoking within 1 month of undergoing a laparoscopic distal gastrectomy with gastroduodenostomy had higher postoperative opioid use than patients who had ceased smoking for more than 1 month and nonsmokers.

Comparative Effectiveness of Parasagittal Interlaminar and Transforaminal Cervical Epidural Steroid Injection in Patients with Cervical Radicular Pain: A Randomized Clinical Trial.

BACKGROUND: Cervical epidural steroid injections (ESI) are performed either by interlaminar (IL) or transforaminal (TF) approaches; however, there is controversy over which is better for safety and efficacy. OBJECTIVES: This clinical trial aimed to compare the effectiveness of the parasagittal IL and TF approaches for cervical ESI in patients who were suffering from cervical radicular pain. STUDY DESIGN: A prospective randomized assessor-blind study. SETTING: The study took place at a single pain clinic within a tertiary medical center in Seoul, Republic of Korea. METHODS: This prospective randomized, assessor-blind trial included 80 patients with cervical radicular pain. We randomly assigned patients to the TF or parasagittal IL approach for cervical ESI. The effectiveness of the 2 groups was compared based on pain intensity using the Numeric Rating Scale (NRS-11) at 1 and 3 months. The Neck Disability Index (NDI), Medication Quantification Scale (MQS), and responders at 1 and 3 months between the 2 groups were compared. RESULTS: The pain intensity of both groups significantly reduced after 1 and 3 months after each procedure (P < 0.001). Two-way repeated measures of analysis of variance showed no significant interaction between group and time for cervical radicular pain (P = 0.266), although NRS-11 pain score was lower in the TF group than the parasagittal IL group after 1 month (P = 0.010). NDI, MQS, and successful responders were not different between the 2 groups at 1 and 3 months after the procedure. We observed 7 cases (18.4%) of vascular visualization in the TF group, although no serious complications were found in either group. LIMITATIONS: This study had no placebo control group and limited follow-up time. CONCLUSIONS: Parasagittal IL ESI may be recommended over the TF ESI in reducing cervical radicular pain, considering both clinical effectiveness and safety.

Comparison between total intravenous anesthesia and balanced anesthesia on postoperative opioid consumption in patients who underwent laparoscopic-assisted distal gastrectomy.

Remifentanil is the most frequently prescribed opioid for total intravenous anesthesia (TIVA) or balanced anesthesia (BA), due to its favorable pharmacological properties. However, several studies have reported opioid-induced hyperalgesia and/or acute tolerance after intraoperatively using remifentanil. In addition, it is imperative to control postoperative pain with lower doses of opioid anesthetic agents. Therefore, we compared the amount of opioid consumption between TIVA with propofol-remifentanil and BA with desflurane-remifentanil, to control postoperative pain in patients who underwent laparoscopic-assisted distal gastrectomy (LADG) with gastroduodenostomy.We retrospectively evaluated demographic variables (age, gender, height, weight, and smoking habits), the duration of general anesthesia (GA), and intraoperatively administered remifentanil consumption through the electronic medical records of patients who underwent LADG with gastroduodenostomy due to early stomach cancer. The primary outcome was postoperative opioid consumption during postoperative day (POD) 2. The secondary outcomes were the incidence of any rescue opioid analgesics administered, numeric rating scale, and various adverse effects during POD 2. We categorized the data in 2 patient groups to compare TIVA with propofol-remifentanil (TIVA group) to BA with desflurane-remifentanil (BA group) on the postoperative opioid analgesic consumption.We divided 114 patients into the TIVA (46 patients) and BA (68 patients) groups. Opioid consumption as a primary outcome was significantly higher in the BA group than in the TIVA group during POD 2 except in the post-anesthesia care unit. The cumulative opioid consumption was significantly higher in the BA than in the TIVA group. The incidence of rescue analgesic at POD 2 was higher in the BA than in the TIVA group. In the TIVA group, remifentanil consumption was higher, and the duration of GA was shorter than that in the BA group. No statistically significant differences were observed when comparing other variables.Our results indicated that the maintenance of GA with TIVA (propofol-remifentanil) reduces opioid consumption for postoperative pain control compared to BA (desflurane-remifentanil) in patients undergoing LADG with gastroduodenostomy.

Effectiveness of and Factors Associated with Balloon Adhesiolysis in Patients with Lumbar Post-Laminectomy Syndrome: A Retrospective Study.

Post-laminectomy syndrome (PLS) is characterized by chronic pain and complex pathological entity after back surgery. An epidural adhesiolysis is considered an effective treatment option for lumbar PLS. In this study, we retrospectively analyzed the outcome and evaluated the predictive factors of combined epidural adhesiolysis and balloon decompression using inflatable balloon catheters in lumbar PLS cases. One hundred and forty-seven subjects were retrospectively assessed and analyzed. The percentages of patients who exhibited treatment response were 32.0%, 24.5%, and 22.4% of the study population at 1, 3, and 6 months, respectively. In multivariate logistic regression analysis, the pain duration was independently associated with the treatment response six months after combined epidural adhesiolysis and balloon decompression (odds ratio = 0.985, 95% confidence interval = 0.971-0.999; p = 0.038). In addition, the receiver operating characteristic curve analysis showed that the area under the curve of pain duration after lumbar surgery was 0.680 (95% confidence interval = 0.597-0.754, p = 0.002), with an optimal cut-off value of ≤14 months, sensitivity of 51.5%, and specificity of 81.4% Our results suggest that an early intervention using combined epidural adhesiolysis and balloon decompression in lumbar PLS patients may be associated with a favorable outcome, even though it has limited effectiveness.

Effects of bilateral stellate ganglion block on autonomic cardiovascular regulation.

BACKGROUND: Stellate ganglion block (SGB) is performed for the diagnosis and treatment of sympathetic dependent pain in the head, neck and upper limbs. However, the effects of bilateral SGB on cardiovascular and autonomic regulation remain unknown. The aim of this study was to assess the effects of bilateral SGB on cardiovascular and autonomic function by measuring heart rate variability (HRV), systolic blood pressure variability (SBPV) and spontaneous baroreflex sensitivity (SBRS). METHODS AND RESULTS: Twenty healthy volunteers were randomly allocated to receive right or left SGB with 8 ml 1% lidocaine solution; after 20 min, the contralateral side SGB was performed. Changes in the RR interval (RRI), systolic blood pressure (SBP), HRV, SBPV and SBRS were assessed before and after bilateral SGB. The low-frequency (LF, 0.04-0.15 Hz) and high-frequency (HF, 0.15-0.4 Hz) components of HRV and SBRS decreased significantly; however, no significant changes were found in RRI, SBP and the LF and HF components of SBPV after bilateral SGB. In subjects with symptoms of vagal blockade, HRV, SBP and SBRS were significantly affected by bilateral SGB. CONCLUSIONS: Bilateral SGB should be performed cautiously because it can reduce cardiac vagal modulation and BRS, especially for those with symptoms of vagal blockade after bilateral SGB.

Effectiveness of lumbar epidural injection in patients with chronic spinal stenosis accompanying redundant nerve roots.

Redundant nerve root syndrome (RNRS) is a phenomenon characterized by the presence of elongated, enlarged, tortuous nerve roots in the lumbar subarachnoid space. It is unclear whether RNRS is caused by spinal stenosis or causes these symptoms.This study evaluated the effects of lumbar epidural steroid injection (LESI) on patients with RNRS and assessed factors associated with RNRS. This retrospective observational cohort study was conducted at a single pain clinic of a university hospital.The medical records of 172 outpatients presenting with low back and/or leg pain from July to December 2014 were analyzed. Pain intensity (numeric rating scale [NRS]) and functional status were assessed at baseline and 2, 4, and 12 weeks after the LESI. Patients were considered moderate responders if they showed a 3-point or >30% reduction in baseline NRS, or said "better than 30%," "a little better," or "I feel an effect." Patients were considered substantial responders if they showed a 5-point or >50% reduction in baseline NRS, or said "better than 50%," "very good," or "much better." Generalized estimating equation (GEE) analysis was performed to identify the factors associated with moderate response to LESI. Factors associated with RNRS were also determined by logistic regression analysis.The proportions of both moderate and substantial responders at 2, 4, and 12 weeks were significantly lower in patients with than without RNRS. GEE analysis showed that RNRS were the only factor significantly associated with moderate response to LESI (OR = 0.400; 95% CI, 0.253-0.632; P < .001). The distance from the conus medullaris to the closest level of stenosis was shorter in patients with than without RNRS (P < .001) and was the only independent factor associated with RNRS on multivariate logistic regression analysis (OR = 0.972; P < .001).LESI was less effective in patients with than without RNRS. The only independent factor significantly associated with RNRS was the distance from the conus medullaris to the nearest moderate stenosis.

Percutaneous Epidural Adhesiolysis Using Inflatable Balloon Catheter and Balloon-less Catheter in Central Lumbar Spinal Stenosis with Neurogenic Claudication: A Randomized Controlled Trial.

BACKGROUND: When conventional interventional procedures fail, percutaneous epidural adhesiolysis (PEA), which has moderate evidence for successful treatment of lumbar spinal stenosis (LSS), has been recommended over surgical treatments. In a previous study, we demonstrated the efficacy of a newly developed inflatable balloon catheter for overcoming the access limitations of pre-existing catheters for patients with severe stenosis or adhesions. OBJECTIVES: This study compared the treatment response of combined PEA with balloon decompression and PEA only in patients with central LSS over 6 months of follow-up. STUDY DESIGN: This study used a randomized, single-blinded, active-controlled trial design. SETTING: This study took place in a single-center, academic, outpatient interventional pain management clinic. METHODS: This randomized controlled study included 60 patients with refractory central LSS who suffered from chronic lower back pain and/or lumbar radicular pain. Patients failed to maintain improvement for > 1 month with epidural steroid injection or PEA using a balloon-less catheter. Patients were randomly assigned to one of 2 interventions: balloon-less (n = 30) and inflatable balloon catheter (n = 30). The Numeric Rating Scale (NRS-11), Oswestry Disability Index (ODI), Global Perceived Effect of Satisfaction (GPES), and Medication Quantification Scale III were each measured at 1, 3, and 6 months after PEA. RESULTS: There was a significant difference between groups in NRS-11 reduction ≥ 50% (or 4 points), ODI reduction ≥ 30% (or 10 points), GPES ≥ 6 and ≥ 4 points at 6 months, and NRS-11 reduction ≥ 50% (or 4 points) at 3 months after PEA (P < .03). The proportion of successful responders was higher in the balloon group than in the balloon-less group throughout the total follow-up period. Furthermore, there was a statistically significant difference between groups at 6 months after PEA (P = .035). LIMITATIONS: The results may vary according to the definition of successful response. Follow-up loss in the present study seemed to be high. CONCLUSION: PEA using the inflatable balloon catheter leads to significant pain reduction and functional improvement compared to PEA using the balloon-less catheter in patients with central LSS.The study protocol was approved by our institutional review board (2012-0235), and written informed consent was obtained from all patients. The trial was registered with the Clinical Research Information Service (KCT 0002093). KEY WORDS: Balloon decompression, central, chronic pain, epidural adhesiolysis, lumbar, percutaneous, radiculopathy, spinal stenosis.

Factors Associated with Successful Responses to Transforaminal Balloon Adhesiolysis for Chronic Lumbar Foraminal Stenosis: Retrospective Study.

BACKGROUND: Recently, transforaminal balloon adhesiolysis was introduced to manage patients with chronic radicular pain occurring with or without low back pain. However, the factors associated with successful responses to transforaminal balloon adhesiolysis are not known. OBJECTIVE: To evaluate the factors associated with successful responses to transforaminal balloon adhesiolysis for chronic lumbar spinal stenosis. STUDY DESIGN: This is a retrospective observational study. SETTING: A single pain clinic of tertiary medical center in Seoul, Republic of Korea. METHODS: From January 2013 to December 2014, a retrospective review of 199 patients with chronic lumbar foraminal stenosis, who were scheduled for transforaminal balloon adhesiolysis, was performed. Patients were considered successful responders if they showed either of the following: 1) a decrease of more than 50% on the numerical rating scale or 2) a decrease of more than 30% on the numerical rating scale and improved functional status 3 months after transforaminal balloon adhesiolysis. Logistic regression analysis was performed to determine the factors associated with successful responses to this surgical procedure. RESULTS: Three months after the transforaminal balloon adhesiolysis, 49.4% of patients were considered successful responders. Multivariate logistic regression analysis showed that factors other than degenerative disc herniation were independently associated with successful responses 3 months after this surgical procedure (odds ratio = 0.327; 95% confidence interval = 0.129 - 0.827; P = 0.018). LIMITATIONS: The definition of successful response used in this study differed from the ones used in previous studies; a different definition may have led to different results. Further, the effects of other factors (ballooning, drugs, and saline washes) could not be excluded from our study. In addition, the correct method of assessing functional status, the Oswestry Disability Index, could not be used in this study; hence, the final results may have been affected. CONCLUSION: These results suggest that transforaminal balloon adhesiolysis can successfully lead to improvement of symptoms in patients with chronic lumbar foraminal stenosis caused primarily by degenerative disc herniation.Institutional Review Board (IRB) approval number: 2016-0228.Key words: Balloon, epidural adhesiolysis, chronic pain, radicular pain, lumbar spine, foraminal stenosis, degenerative disc.

Smoking May Increase Postoperative Opioid Consumption in Patients Who Underwent Distal Gastrectomy With Gastroduodenostomy for Early Stomach Cancer: A Retrospective Analysis.

OBJECTIVES: Although nicotine has an analgesic effect, the incidence and severity of chronic pain is higher in smokers than nonsmokers. Acute pain is more intense in smokers during the perioperative period. This study evaluated whether smokers require higher doses of opioid to reduce pain when they undergo surgery. METHODS: A retrospective review of 236 patients who had intravenous patient-controlled analgesia after distal gastrectomy with gastroduodenostomy between October 2013 and September 2014 was performed to analyze the difference in postoperative opioid requirements between smokers and nonsmokers. Total opioid consumption was observed from the day of operation to postoperative day 2. Patients were grouped into smokers (N=117) and nonsmokers (N=119) for comparison. Simple and multiple regression analyses were performed to identify predictors of postoperative opioid requirements. RESULTS: Opioid consumption by male smokers was higher than nonsmokers. Multiple regression analysis showed that age, smoking, and amount of intraoperative remifentanil were the only significant factors for postoperative opioid requirements. DISCUSSION: Our results suggest that smokers undergoing distal gastrectomy with gastroduodenostomy required more opioid than nonsmokers for postoperative pain. Old age, smoking status, and increment of remifentanil use seemed to be predictors of postoperative opioid consumption.

Optimal volume of injectate for fluoroscopy-guided cervical interlaminar epidural injection in patients with neck and upper extremity pain.

There is no study of optimal volume of contrast medium to use in cervical interlaminar epidural injections (CIEIs) for appropriate spread to target lesions. To determine optimal volume of contrast medium to use in CIEIs. We analyzed the records of 80 patients who had undergone CIEIs. Patients were divided into 3 groups according to the amount of contrast: 3, 4.5, and 6 mL. The spread of medium to the target level was analyzed. Numerical rating scale data were also analyzed. The dye had spread to a point above the target level in 15 (78.9%), 22 (84.6%), and 32 (91.4%) patients in groups 1 to 3, respectively. The dye reached both sides in 14 (73.7%), 18 (69.2%), and 23 (65.7%) patients, and reached the ventral epidural space in 15 (78.9%), 22 (84.6%), and 30 (85.7%) patients, respectively. There were no significant differences of contrast spread among the groups. There were no significant differences in the numerical rating scale scores among the groups during the 3 months. When performing CIEIs, 3 mL medication is sufficient volume for the treatment of neck and upper-extremity pain induced by lower cervical degenerative disease.