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These days, because of the coronavirus, all countries are introducing online university systems. Online universities have the advantage of allowing students to take classes anytime, anywhere, 24 h a day, but lectures are given in a non-face-to-face manner between instructors and students. Thus, while students are taking classes on a web-based basis, the problem arises that concentration on the lectures is significantly reduced. Therefore, in order to solve these problems, in this paper, we propose a level-wise learning algorithm based on the difficulty level of the test problem, and we present the simulation results. In order to improve this problem, in this paper, we propose an automatic music recommendation algorithm based on fuzzy reasoning that can improve the level of learning and lecture concentration, and we show our results on developing a web-based, smart e-learning software. As a result of computer simulation, it was proved that the learning test method, considering by level the difficulty of the test and the incorrect answer rate, was more effective than the existing test method, judged the student’s grades fairly, and improved the risk of unfairly failing the test by 30%.

A distribution system was designed and operated by considering unidirectional power flow from a utility source to end-use loads. The large penetrations of distributed generation (DG) into the existing distribution system causes a variety of technical problems, such as frequent tap changing problems of the on-load tap changer (OLTC) transformer, local voltage rise, protection coordination, exceeding short-circuit capacity, and harmonic distortion. In view of voltage regulation, the intermittent fluctuation of the DG output power results in frequent tap changing operations of the OLTC transformer. Thus, many utilities limit the penetration level of DG and are eager to find the reasonable penetration limits of DG in the distribution system. To overcome this technical problem, utilities have developed a new voltage regulation method in the distribution system with a large DG penetration level. In this paper, the impact of DG on the OLTC operations controlled by the line drop compensation (LDC) method is analyzed. In addition, a generalized determination methodology for the DG penetration limits in a distribution substation transformer is proposed. The proposed DG penetration limits could be adopted for a simplified interconnection process in DG interconnection guidelines.

Background Although preoxygenation is an essential procedure for safe endotracheal intubation, in some cases securing sufficient time for tracheal intubation may not be possible. Patients with head and neck cancer might have a difficult airway and need a longer time for endotracheal intubation. We hypothesized that the extended apneic period with preoxygenation via a high-flow nasal cannula (HFNC) is beneficial to patients who undergo head and neck surgery compared with preoxygenation with a simple mask. Methods The study was conducted as a single-center, single-blinded, prospective, randomized controlled trial. Patients were divided into groups based on one of the two preoxygenation methods: HFNC group or simple facemask (mask group). Preoxygenation was performed for 5 minutes with each method, and endotracheal intubation for all patients was performed using a video laryngoscope. Oxygen partial pressures of the arterial blood were compared at the predefined time points. Results For the primary outcome, the mean arterial oxygen partial pressure (PaO2) immediately after intubation was 454.2 mm Hg (95% confidence interval [CI], 416.9–491.5 mm Hg) in the HFNC group and 370.7 mm Hg (95% CI, 333.7–407.4 mm Hg) in the mask group (P=0.002). The peak PaO2 at 5 minutes after preoxygenation was not statistically different between the groups (P=0.355). Conclusions Preoxygenation with a HFNC extending to the apneic period before endotracheal intubation may be beneficial in patients with head and neck cancer.

Background Severe burns cause pathophysiological processes that result in mortality. A laboratory biomarker, red cell distribution width (RDW), is known as a predictor of mortality in critically-ill patients. We examined the association between RDW and postoperative mortality in severe burn patients. Methods We retrospectively analyzed medical data of 731 severely burned patients who underwent surgery under general anesthesia. We evaluated whether preoperative RDW value can predict 3-month mortality after burn surgery using receiver operating characteristic (ROC) curve analysis, logistic regression, and Cox proportional-hazards regression analysis. Mortality was also analyzed according to preoperative RDW values and incidence of postoperative acute kidney injury (AKI). Results The 3-month mortality rate after burn surgery was 27.1% (198/731). The area under the ROC curve of preoperative RDW to predict mortality after burn surgery was 0.701 (95% confidence interval [CI], 0.667–0.734; P < 0.001) with a cut-off point of 12.9. The adjusted hazard ratio in patients with RDW > 12.9 was 1.238 (95% CI, 1.138–1.347; P < 0.001). Subgroup analysis showed that the survival rate was 88.8% for the non-AKI group with RDW ≤ 12.9 and 17.6% for the AKI group with RDW > 12.9. Preoperative RDW was considered an independent risk factor for mortality (odds ratio, 1.679; 95% CI, 1.378–2.046; P < 0.001). Conclusions Preoperative RDW may predict 3-month postoperative mortality in patients with severe burns, while preoperative RDW > 12.9 and postoperative AKI may further increase mortality after burn surgery.

Background The preemptive visceral analgesic effect of regional nerve block has not been adequately investigated to date. We evaluated the preemptive visceral analgesic effect of thoracic paravertebral block (TPVB) in patients undergoing laparoscopic cholecystectomy (LC) in whom pre-incisional rectus sheath block (RSB) was used to minimize somatic surgical pain. Methods In this prospective, randomized, assessor-blind study, 70 patients scheduled for elective LC were randomly assigned to the pre-TPVB (n = 35) or the post-TPVB (n = 35) group. Both groups received pre-incisional RSB, and patients in the pre-TPVB group received TPVB before skin incision while those in the post-TPVB group received TPVB after skin closure. The primary outcome was the total rescue analgesic consumption (morphine equianalgesic dose) during the 24 h post-surgery. The secondary outcomes were the cumulative analgesic consumption and pain intensity for 24 h after surgery, and adverse events. Results Pre-TPVB significantly reduced total rescue analgesic consumption (estimated mean [95% CI]) during the 24 h after surgery than post-TPVB (16.9 [14.5, 19.3] vs. 25.3 [22.8, 27.7] mg, estimated difference: −8.3 [−11.8, −4.9], P < 0.001). The cumulative rescue analgesic consumption was significantly lower in the pre-TPVB group from 2–24 h after surgery (P < 0.001). The postoperative pain intensity was significantly lower in the pre-TPVB group as well at 0.5–6 h after surgery. There were no adverse events in both groups. Conclusions Pre-incisional TPVB conferred a significant preemptive visceral analgesic effect in patients undergoing LC, and significantly reduced the amount of postoperative opioid consumption.

Background: Increasing evidence supporting the clinical effectiveness of cooled radiofrequency ablation (RFA) therapy for genicular nerves in patients with chronic knee osteoarthritis (OA) exists. However, no study has been conducted to eliminate the potential influence of a placebo effect associated with this procedure. Therefore, we evaluated the efficacy of cooled RFA compared with a sham procedure in patients with painful knees due to OA. Methods: In this double-blind, randomized, controlled study, participants were randomly assigned to receive cooled RFA of the knee (cooled RFA group, n = 20) or a sham procedure (sham group, n = 20). The primary outcome was the proportion of successful responders at the three-month follow-up. The secondary outcomes were successful responders at one and six months; pain intensity of the knee; functional status; medication; and satisfaction at one, three, and six months after the procedures. Results: For the primary outcome, the successful responder rate was significantly higher in the cooled RFA group (76.5%) than in the sham group (33.3%) (p = 0.018). For the secondary outcome, more successful responders were observed in the cooled RFA group than in the sham group at one and six months after the procedure (p = 0.041 and 0.007, respectively). The decreased knee pain intensity was maintained throughout the six-month follow-up period in the cooled RFA group. No differences were observed in functional status, medication change, or satisfaction in both groups. Conclusions: The cooled RFA of genicular nerves offers significant pain relief and surpasses the effects attributable to a placebo.

Percutaneous epidural balloon neuroplasty (PEBN) can be used to perform balloon decompression combined with percutaneous epidural neuroplasty (PEN), leading to significant pain relief and functional improvement in patients with lumbar spinal stenosis. Several studies have demonstrated the effectiveness of PEBN and supported its relatively long-term outcomes (at least 6 months, sustained for up to 12 months). Balloon neuroplasty appears to be superior to conventional PEN. Moreover, it has been shown to be effective in patients unresponsive to conventional PEN or in those with post lumbar surgery syndrome. In addition, balloon neuroplasty achieved successful outcomes regardless of the approach used, such as retrodiscal, transforaminal, contralateral interlaminar, or caudal. Chronic lumbar radicular pain without back pain, neurogenic claudication, and minimal neuropathic component were favorable predictors of successful PEBN from a symptomatic perspective. A short duration of pain after lumbar surgery, lumbar foraminal stenosis caused primarily by degenerative disc, mild foraminal stenosis, and perineural adhesion by degenerative discs were associated with successful outcomes of PEBN from pathological aspects. Ballooning ≥ 50% of the target sites and complete contrast dispersion after ballooning seemed to be crucial for successful outcomes from a technical perspective. In addition, PEBN was effective regardless of the accompanying redundant nerve roots or a mild degree of spondylolisthesis. Studies on balloon neuroplasty have reported occasional minor and self-limiting complications; however, no PEBN-related significant complications have been reported. Given the present evidence, balloon neuroplasty appears to be a safe and effective procedure with minimal complications for the treatment of lumbar spinal stenosis.

Background In some patients with neuropathic pain (NP), such as complex regional pain syndrome (CRPS), itching rather than pain is the main symptom making diagnosis and treatment difficult. Case We report a case of a 23-year-old male with a history of hypoxic brain damage who presented with pruritus of the left foot and ankle. His left foot was fractured, and he underwent surgery 6 months previously. After the operation and cast application, he developed uncontrolled pruritus, swelling, sweating, and flushing of the left foot skin with limping. On examination, he showed well-known features of CRPS without pain. He was diagnosed with an atypical CRPS with neuropathic itching (NI). With treatment modalities used for NP and CRPS, his pruritus subsided gradually, and the his ankle mobility improved. Conclusions Unexplained itching can be the main symptom in some CRPS patients. Treatment according to NP can improve symptoms of NI in CRPS patients.

Background and Objectives: With the aging population, the incidence of degenerative lumbar spinal stenosis (LSS) is increasing. Sarcopenia is an age-related muscular decrease. Although epidural balloon neuroplasty is effective in patients with LSS refractory to conventional treatments, its effect has not been assessed in patients with sarcopenia. Therefore, this study evaluated the effect of epidural balloon neuroplasty in patients with LSS and sarcopenia. Materials and Methods: This retrospective study reviewed the following details from the electronic medical records: patient characteristics, including sex, age, body mass index, diabetes, hypertension, stenosis grading, pain duration, location, pain intensity, and medications. Back and leg pain intensity was evaluated before and after the procedure at one, three, and six months during the follow-up period. A generalized estimating equations model was used at six months follow-up. Patients were divided into sarcopenia and non-sarcopenia groups using the cross-sectional area of the psoas muscle at the level of L3 on magnetic resonance imaging. Results: A total of 477 patients were included (sarcopenia group: 314 patients, 65.8%; non-sarcopenia group: 163 patients, 34.2%). Age, sex, body mass index, and medication quantification scale III were statistically different between both groups. The generalized estimating equations analyses—with unadjusted and adjusted estimation—revealed a significantly reduced pain intensity after the procedure compared to the baseline in both groups. The difference in pain intensity between both groups was not statistically different. Conclusions: Percutaneous epidural balloon neuroplasty may be considered for patients with chronic lumbar LSS regardless of accompanying sarcopenia.

Abstract Although epidural patient-controlled analgesia (PCA) to control postoperative pain after total knee arthroplasty (TKA), the relationship of epidural PCA with postoperative bleeding remains controversial. Therefore, we aimed to evaluate the effect of epidural and intravenous PCA on postoperative bleeding in patients undergoing unilateral TKA. Total of 2467 patients who underwent TKA were divided to intravenous PCA (n = 2339) or epidural PCA (n = 128) group. After 1:1 propensity score-matching, 212 patients were analyzed to assess the associations between the perioperative blood loss and epidural PCA between the groups. Mean postoperative blood loss was significantly greater in epidural PCA than in intravenous PCA (900.9 ± 369.1 mL vs. 737.8 ± 410.1 mL; P = 0.007). The incidence of red blood cell (RBC) administration (> 3 units) was significantly higher in epidural PCA than in intravenous PCA (30.2% vs. 16.0%; OR 2.5; 95% CI 1.201–5.205; P = 0.014). Epidural PCA may be strongly related to postoperative bleeding and the incidence of RBC transfusion of more than 3 units after unilateral TKA, as compared to intravenous PCA. Therefore, the use of epidural PCA may be carefully considered for postoperative pain management in TKA.

Background Spinal cord stimulation (SCS) can be successfully performed using highly developed implantation techniques. However, anatomical barriers, such as epidural adhesion, may impede placing the electrode for SCS in an adequate position. Case A 60-year-old female who had SCS with an electrode at the T9-10 level removed because she had a wound infection at the back incision site. After the wound infection was completely resolved, we tried to re-insert the SCS electrode. However, it was difficult to advance it up to the T11 level due to epidural adhesion. We performed a combined epidural adhesiolysis using balloon decompression with an inflatable balloon catheter. After that, the SCS lead was successfully placed up to the T11 level, and implantation of SCS was performed. Conclusions When a patient has epidural adhesion, an epidural adhesiolysis with an inflatable balloon catheter may help the insertion of the SCS electrode in the epidural space.

Background. In patients with postherpetic neuralgia (PHN), the effectiveness of epidural block and the benefits of adjuvant hypertonic saline (HS) have not been fully determined. Therefore, we investigated these issues in this study. Methods. At a tertiary medical center’s single pain clinic in Seoul, Republic of Korea, patients complaining of PHN even after 4 months of herpes zoster onset were enrolled and randomly assigned to either the HS or normal saline (NS) group. After epidural block with adjuvant HS or NS administration according to each protocol, outcomes were assessed at baseline and one and three months after the intervention. The primary outcome was pain intensity on the numerical rating scale (NRS). The secondary outcomes were the insomnia severity index (ISI), the medication quantification scale (MQS), and the global perceived effect of satisfaction (GPES). Results. Thirty-six patients (NS: 17, HS: 19) were included in the intention-to-treat analysis. The estimated pain intensity decreased in both groups at one and three months after the procedure (P

Severe burns may lead to a series of pathophysiological processes that result in death. Machine learning models that demonstrate prognostic performance can be used to build analytical models to predict postoperative mortality. This study aimed to identify machine learning models with the best diagnostic performance for predicting mortality in critically ill burn patients after burn surgery, and then compare them. Clinically important features for predicting mortality in patients after burn surgery were selected using a random forest (RF) regressor. The area under the receiver operating characteristic curve (AUC) and classifier accuracy were evaluated to compare the predictive accuracy of different machine learning algorithms, including RF, adaptive boosting, decision tree, linear support vector machine, and logistic regression. A total of 731 patients met the inclusion and exclusion criteria. The 90-day mortality of the critically ill burn patients after burn surgery was 27.1% (198/731). RF showed the highest AUC (0.922, 95% confidence interval = 0.902–0.942) among the models, with sensitivity and specificity of 66.2% and 93.8%, respectively. The most significant predictors for mortality after burn surgery as per machine learning models were total body surface area burned, red cell distribution width, and age. The RF algorithm showed the best performance for predicting mortality.

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 (β = −0.08; 95% confidence interval (CI), −0.11 to −0.04; P

While the postoperative outcome is favorable, post-thyroidectomy pain is considerable. Reducing the postoperative acute pain, therefore, is considered important. This study investigated whether the pain intensity and need for rescue analgesics during the immediate postoperative period after thyroidectomy differ according to the methods of anesthesia. Seventy-two patients undergoing total thyroidectomy under general anesthesia were examined. Patients were randomly assigned to undergo either total intravenous anesthesia with remifentanil and propofol (TIVA, n = 35) or propofol induction and maintenance with desflurane and nitrous oxide (volatile anesthesia [VA], n = 37). The mean administered dose of remifentanil was 1977.7 ± 722.5 μg in the TIVA group, which was approximately 0.268 ± 0.118 μg/min/kg during surgery. Pain scores based on a numeric rating scale (NRS) and the need for rescue analgesics were compared between groups at the postoperative anesthetic care unit (PACU). The immediate postoperative NRS values of the TIVA and VA groups were 5.7 ± 1.7 and 4.7 ± 2.3, respectively (P = 0.034). Postoperative morphine equianalgesic doses in the PACU were higher in the TIVA group than in the VA group (16.7 ± 3.8 mg vs. 14.1 ± 5.9 mg, P = 0.027). The incidence of immediate postanesthetic complications did not differ significantly between groups. In conclusion, more rescue analgesics were required in the TIVA group than in the VA group to adequately manage postoperative pain while staying in the PACU after thyroidectomy.

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.

A distribution system was designed and operated by considering unidirectional power flow from a utility source to end-use loads. The large penetrations of distributed generation (DG) into the existing distribution system causes a variety of technical problems, such as frequent tap changing problems of the on-load tap changer (OLTC) transformer, local voltage rise, protection coordination, exceeding short-circuit capacity, and harmonic distortion. In view of voltage regulation, the intermittent fluctuation of the DG output power results in frequent tap changing operations of the OLTC transformer. Thus, many utilities limit the penetration level of DG and are eager to find the reasonable penetration limits of DG in the distribution system. To overcome this technical problem, utilities have developed a new voltage regulation method in the distribution system with a large DG penetration level. In this paper, the impact of DG on the OLTC operations controlled by the line drop compensation (LDC) method is analyzed. In addition, a generalized determination methodology for the DG penetration limits in a distribution substation transformer is proposed. The proposed DG penetration limits could be adopted for a simplified interconnection process in DG interconnection guidelines. [ABSTRACT FROM AUTHOR]

Effect of tension coating on iron loss has been investigated as a function of excitation induction and frequency in thin-gauged 3% silicon steel sheets and iron loss after tension coating has been evaluated by loss separation method. In order to additionally reduce iron loss, tension coating without forsterite base coating was applied on surfaces of the thin grain-oriented sheets. Reduction in total loss due to the tension coating results from combination of hysteresis loss and anomalous loss, but the latter plays a major role in the loss reduction. The coated sheets show a maximum iron loss reduction of 18% at an excitation induction of 1.0 T and an excitation frequency of 60 Hz. [ABSTRACT FROM AUTHOR]

Background. Although fluoroscopic guidance is recommended highly for more accurate lumbar interlaminar epidural steroid injection (L-ESI), many physicians still use a nonimage-guided approach for L-ESIs. However, because of its associated risk of radiation and increased medical expense, the cost-effectiveness and safety of fluoroscopy-guided ESI have been called into question. The goal of this retrospective matched paired analysis in the same individuals was to assess the effectiveness and prevalence of complications of nonimage-guided L-ESI compared to those of fluoroscopy-guided L-ESI. Methods. Between 2015 and 2016, 94 patients who received both nonimage- and fluoroscopy-guided L-ESIs were analyzed retrospectively. The changes of the numeric rating scale (NRS) in pain intensity and functional outcome and the differences in the number of complications between blind and fluoroscopy-guided L-ESIs in the same individuals were evaluated by a matched paired analysis. Results. Of the 94 patients, the differences in NRS before and after the procedure were 1.29 (95% confidence interval (CI) = 0.94–1.65) for the nonimage-guided group and 1.64 (95% CI = 1.28–2.01) for the fluoroscopy-guided group (p=0.16). More subjective functional improvement was observed in fluoroscopy-guided L-ESI (57, 60.6%) than in nonimage-guided L-ESI (47, 50.0%) without statistical significance (p=0.16). Nine (9.6%) patients in the nonimage-guided group experienced complications related to the procedure overall compared to 4 (4.3%) in the fluoroscopy-guided group (p=0.27). Conclusions. In this study, both blind and image-guided L-ESI techniques included similar extents of postprocedural outcomes and complications. Physicians should consider the risks associated with the two different techniques overall and develop ways to individualize the procedure to decrease the risk of complications and improve the positive outcomes of lumbar epidural steroid injections.

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.

Although endoscopic ultrasound-guided celiac neurolysis (EUS-CN) and percutaneous celiac neurolysis (PCN) are utilized to manage intractable pain in pancreatic cancer patients, no direct comparison has been made between the two methods. We compared the efficacy and safety of EUS-CN and PCN in managing intractable pain in such patients. Sixty pancreatic cancer patients with intractable pain were randomly assigned to EUS-CN (n = 30) or PCN (n = 30). The primary outcomes were pain reduction in numerical rating scale (NRS) and opioid requirement reduction. Secondary outcomes were: successful pain response (NRS decrease ≥50% or ≥3-point reduction from baseline); quality of life; patient satisfaction; adverse events; and survival rate at 3 months postintervention. Both groups reported sustained decreases in pain scores up to 3 months postintervention (mean reductions in abdominal pain: 0.9 (95% confidence interval (CI): −0.8 to 4.2) and 1.7 (95% CI: −0.3 to 2.1); back pain: 1.3 (95% CI: −0.9 to 3.4) and 2.5 (95% CI: −0.2 to 5.2) in EUS-CN, and PCN groups, respectively). The differences in mean pain scores between the two groups at baseline and 3 months were −0.5 (p = 0.46) and −1.4 (p = 0.11) for abdominal pain and 0.1 (p = 0.85) and −0.9 (p = 0.31) for back pain in favor of PCN. No significant differences were noted in opioid requirement reduction and other outcomes. EUS-CN and PCN were similarly effective and safe in managing intractable pain in pancreatic cancer patients. Either methods may be used depending on the resources and expertise of each institution.

Several treatment modalities have been proposed for foraminal stenosis, but the treatment options remain unsatisfactory. Previous studies have shown that transforaminal balloon adhesiolysis may be effective in patients with refractory lumbar foraminal stenosis. However, in patients with a high iliac crest, balloon catheter insertion may be difficult via a conventional transforaminal approach (particularly targeting the L5–S1 foramen). It has been reported that an epidural catheter can be placed easily by a contralateral interlaminar retrograde foraminal approach. Therefore, we applied this approach to L5–S1 transforaminal balloon adhesiolysis in patients with a high iliac crest. We retrospectively analyzed data from 22 patients who underwent combined epidural adhesiolysis and balloon decompression (balloon adhesiolysis) using the novel foraminal balloon catheter via a contralateral interlaminar retrograde foraminal approach. The pain intensity significantly decreased over the three-month period after balloon adhesiolysis (p < 0.001). There were no complications associated with the balloon procedure. The present study suggests that balloon adhesiolysis for L5-S1 foramen via a contralateral interlaminar retrograde foraminal approach may be an effective alternative for patients with a high iliac crest and refractory lumbar radicular pain due to lumbar foraminal stenosis. In addition, detailed procedural aspects are described here.

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.

Epidural neuroplasty, often called percutaneous epidural adhesiolysis, is often performed in refractory patients with chronic lumbar radiculopathy or neurogenic claudication. Recent studies have showed that decompressive adhesiolysis with an inflatable balloon catheter (balloon neuroplasty) is efficient in patients who experience refractory pain from epidural steroid injection or even epidural neuroplasty with a balloon-less catheter. However, exact indications or predictive factors for epidural balloon neuroplasty have not been fully evaluated. Therefore, to assess associated factors that could affect a favorable outcome, we analyzed a prospectively collected multicenter cohort of patients with chronic refractory lumbar foraminal stenosis after balloon neuroplasty. At the 6-month point in follow-up, 92 (44.4%) patients among 207 subjects were classified as successful responders according to a robust combination of outcome measures. Multivariate logistic regression analysis also showed that mild grade lumbar foraminal stenosis may be an independent factor associated with a successful response 6 months after balloon neuroplasty (odds ratio = 2.829; 95% confidence interval = 1.351−5.923; p = 0.006). However, we found that there were 29.4% and 24.6% successful responders with moderate and severe foraminal stenosis, respectively. Attempting balloon neuroplasty in refractory lumbar foraminal stenosis, especially mild grade, may be worthwhile.

Combined balloon decompression and epidural adhesiolysis has been reported to be effective in refractory lumbar spinal stenosis. Many cases of intractable stenosis have symptom-related multiple target sites for interventional treatment. In this situation it may not be possible to perform balloon adhesiolysis, or even only epidural adhesiolysis, for all target sites. Therefore, this multicenter prospective observational study aimed to evaluate the relationship of successful ballooning rate for multiple target sites with clinical outcome. Based on the ballooning success rate of multiple target sites, the patients were divided into three groups: below 50%, 50−85%, and above 85% ballooning. A greater ballooning success rate for multiple target sites provided a more decreased pain intensity and improved functional status in patients with chronic refractory lumbar spinal stenosis, and the improvement was maintained for 6 months. The estimated proportions of successful responders according to a multidimensional approach in the below 50%, 50−85%, and above 85% balloon success groups at 6 months after the procedure were 0.292, 0.468, and 0.507, respectively (p = 0.038). Our study suggests the more successful balloon adhesiolysis procedures for multiple target lesions are performed, the better clinical outcome can be expected at least 6 months after treatment.

Adrenal insufficiency, which is related to hemodynamic instability and increased mortality, has been reported in patients with advanced liver disease regardless of the presence of septic conditions. In this regard, the hepatoadrenal syndrome has been recently proposed as adrenal insufficiency in critically ill patients with liver disease. We describe here a 67-year-old female patient with hepatic failure and adrenal insufficiency. The patient showed stable vital signs and no evidence of sepsis preoperatively. Despite hydrocortisone replacement and inotropics administration, severe intraoperative hemodynamic instability was observed. Hydrocortisone administration was continued postoperatively, nevertheless inotropics could not be tapered. On postoperative day 11, the patient died due to pneumonia and septic shock. Hepatoadrenal syndrome may have played a key role in her severe hemodynamic fluctuation and poor outcome, reinforcing the importance of adrenal function in the liver transplantation surgery.