Failed back surgery syndrome (FBSS) is a commonly encountered disease after lumbar surgery. There are many cases where it is difficult to choose a treatment because no specific cause can be found. Nevertheless, according to recent reports, adhesiolysis has shown reasonable evidence. However, considering its poor cost-effectiveness, adhesiolysis cannot be used as the first line of treatment. FBSS patients often suffer from chronic pain; accordingly, they become frustrated when this treatment produces a poor response. Therefore, before the procedure, the target group must be selected carefully. We sought to identify the pre-procedure factors predicting the effect of adhesiolysis in FBSS. A total of 150 patients were evaluated and analyzed retrospectively. Of these 150 patients, 69 were classified as responders three months after the procedure (46%). The outer diameter of the catheter during the procedure and grade of foraminal stenosis were correlated with the procedure effect. In conclusion, of the 2.1 mm diameter of the catheter, 1.7 mm of it was used during the procedure, and the milder the foraminal stenosis, the greater the pain reduction effect was three months after the procedure.

Background and Objectives: The interspace between the popliteal artery and the posterior capsule of the knee (iPACK) block has been widely used in perioperative settings to control posterior knee pain and can additionally be used for chronic knee pain. In this cadaveric study, we aimed to investigate the needle tip position and its proximity to the articular branch of the tibial nerve (ABTN) during an iPACK-targeted radiofrequency procedure. Materials and Methods: An ultrasound-guided iPACK block was performed on 20 knees of 10 cadavers. We injected 0.1 mL each of blue and green gelatinous dye near the tibial artery (point A) and posterior knee capsule (point B), respectively, and evaluated the spread of both around the ABTN. For a hypothetical conventional radiofrequency ablation (RFA) lesion (diameter, 2.95 mm) and cooled RFA lesion (diameter, 4.9 mm), we counted the number of specimens in which the ABTNs would be captured. Results: The percentage of specimens in which the ABTN would be captured by a cooled RFA lesion was 64.71% at point A and 43.75% at point B (p = 0.334). Meanwhile, the percentage of specimens in which the ABTN would be captured by a conventional RFA lesion was 58.82% from point A and 25% from point B (p = 0.065). Conclusions: When performing an RFA-based iPACK block, the needle tip may be positioned either lateral to the tibial artery or in the space between the posterior knee capsule and the tibial artery. However, more studies with larger samples are needed to verify these results before the clinical use of this procedure can be recommended.

Background/Objectives: Catheter-related bladder discomfort (CRBD) is a common complication that patients with Foley catheters may experience following surgery. Previous studies have suggested that nefopam can reduce the incidence and severity of CRBD; however, dose-dependent effects (20 mg vs. 40 mg) have not been directly compared. Therefore, this study aimed to evaluate the dose-dependent effects of nefopam on CRBD, determine its effective dose, and assess the incidence of associated side effects. Methods: Electronic medical records of patients aged 18–70 years with American Society of Anesthesiologists physical status I–III who underwent elective transurethral ureteroscopic lithotripsy under general anesthesia from August 2016 to December 2022 were reviewed. Patients were categorized into three groups: premedication with intravenous nefopam 20 mg (group N20), premedication with nefopam 40 mg (group N40), or no premedication (control, group C). Results: The incidence rates of CRBD were 85.7% in group C, 81.3% in group N20, and 51.4% in group N40, showing a significant difference among the groups (p = 0.003, Pearson’s chi-squared test). Postoperative NRS was significantly different among the groups (p < 0.001, one-way ANOVA). In post hoc analysis, both group N20 and group N40 showed significantly lower scores compared to group C (p = 0.002, p = 0.001 respectively). The severity of CRBD also decreased in a dose-dependent manner, which was considered significant. No significant differences were observed among the groups in terms of intraoperative hemodynamic stability or postoperative nausea and vomiting. Conclusions: The administration of nefopam 40 mg significantly reduced the incidence and severity of CRBD compared with no premedication.