Tranexamic acid (TXA) protects against endothelial glycocalyx injury in vitro. We aimed to evaluate whether TXA could protect against endothelial glycocalyx degradation in patients undergoing posterior lumbar fusion surgery. Patients aged 30–80 years were enrolled. The TXA group was administered a loading dose of 10 mg/kg, followed by a 1 mg/kg/h infusion. Serum syndecan-1 and heparan sulfate concentrations, which are biomarkers of glycocalyx degradation, were measured at preoperative baseline (T0), immediately post-surgery (T1), and 2 h post-surgery (T2). Postoperative complications were assessed, including hypotension, desaturation, and acute kidney injury. Among the 121 patients who completed the study, 60 received TXA. There were no significant differences in the marker concentrations at each time point. However, the postoperative increase in syndecan-1 levels from baseline was significantly attenuated in the TXA group compared with the control group (median (interquartile range); T1 vs. T0: −1.6 (−5.3–2.6) vs. 2.2 (−0.7–4.8), p = 0.001; T2 vs. T0: 0.0 (−3.3–5.5) vs. 3.6 (−0.1–9.3), p = 0.013). Postoperative complications were significantly associated with the magnitude of the change in syndecan-1 levels (for T2 vs. T0: odds ratio: 1.08, 95% confidence interval: 1.02–1.14, p = 0.006). TXA administration was associated with reduced syndecan-1 shedding in patients undergoing posterior lumbar fusion surgery.

The retrodural space of Okada (RSO) is a potential space located posterior to the ligamentum flavum. It can complicate epidural injections owing to its communication with the epidural space and facet joints. The purpose of this study was to clarify the anatomical structures of the cervical RSO and adjacent ligamentous tissues in cadavers. Cervical spine specimens from 15 embalmed cadavers were used for serial sectional dissection, histological verification, and micro‐computed tomography (micro‐CT) analysis. Micro‐CT images of the RSO were acquired after phosphotungstic acid preparation at the C5‐7 levels. The RSO was examined meticulously on the basis of its three‐dimensional (3D) topography. The 3D shape of the cervical RSO was successfully visualized using micro‐CT imaging reconstruction. It had clear anatomical communications with the epidural space, facet joints, and interspinous space. Histological examination confirmed the presence of loose connective tissue within the RSO, which probably facilitates these communications. This cadaveric study demonstrated the 3D shape of the cervical RSO and its communications with adjacent anatomical structures. Further clinical studies are needed to explore the potential implications of these findings for cervical epidural injections.

Background and Objectives: Fascia iliaca compartment block (FICB) is an effective and relatively safe technique in perioperative pain management for hip surgery. However, blockade of the obturator nerve (ON) using this technique remains controversial. This study aimed to compare dye spread patterns and nerve involvement in the suprainguinal FICB (S-FICB) and infrainguinal FICB (I-FICB) approaches using different volumes of dye. Materials and Methods: Following randomization, 6 S-FICBs and 6 I-FICBs were performed on the left or right sides of 6 unembalmed cadavers. For each block, 30 mL or 60 mL of dye solution was injected. The extent of dye spreading and the staining pattern in the lumbar plexus branches were investigated using anatomical dissection. Results: Twelve injections were successfully completed. The lateral femoral cutaneous nerve (LFCN) and femoral nerve (FN) were consistently stained in all injections. Extended dye spread toward lumbar plexus branches was observed volume-dependently in S-FICBs. However, I-FICBs with an increased volume only showed dye spreading in the caudad direction limited to within the fascia iliaca. When 30 mL of dye was used, the ON was not stained with either approach. A stained ON was only observed in S-FICBs when 60 mL of dye was used. Conclusions: In this cadaveric evaluation, the ON was not stained in either FICB approach with the volume of injectate commonly used in clinical practice. The S-FICBs but not I-FICBs using a high volume of injectate resulted in extended spreading to the lumbar plexus branches.

Purpose: Cervical transforaminal epidural steroid injection (TFESI) is a common treatment for cervical radiculopathy but carries potential risks because of the presence of crucial arteries in the intervertebral foramina (IVF). This study analyzed the precise anatomical location of the segmental spinal artery (SSA) within the cervical IVF using 3D micro-CT imaging to provide guidance for safer TFESI procedures. Participants and Methods: Fourteen embalmed cadavers were used in this study: three for serial sectional dissection, two for histological examination, and nine for micro-CT analysis. Each IVF was divided into quadrants (ASQ, antero-superior quadrant; PSQ, postero-superior quadrant; AIQ, antero-inferior quadrant; PIQ, postero-inferior quadrant) for detailed measurements of SSA locations, comparing dimensions and spatial relationships among C4– 5, C5– 6, and C6– 7 levels. Results: Forty-four IVFs were analyzed by micro-CT, and the results revealed that SSAs were predominantly located in the ASQ (36 of 44 cases, 82%) and PSQ (8 of 44 cases, 18%) of the IVF. No SSAs were observed in the AIQ and PIQ. Significant dimensions and shapes were consistent across individuals, with cervical IVF increasing in size from C4– 5 to C6– 7. Conclusion: Together, these findings demonstrated the predominance of SSAs in the ASQ, emphasizing the need for precise anatomical guidance during TFESI to avoid vascular injury. In addition, the cervical spine exhibits anatomical variability, indicating that greater caution is required when treating the cervical spine compared with the lumbar spine and highlighting the importance of targeting the PIQ to avoid the SSA and other vascular structures.

Background: During pediatric epilepsy surgery, due to low circulating blood volume, intraoperative bleeding can result in significant hemodynamic instability, thereby requiring meticulous hemodynamic and transfusion strategies. Knowing the source of bleeding during the procedure would allow medical staff to better prepare the perioperative protocols for these patients. We compared intraoperative bleeding between the first (involving skin to meninges) and second (involving brain parenchyma) stages of epilepsy surgery to investigate the differences between various anatomical sites.Methods: We reviewed the electronic medical records of 102 pediatric patients < 14 years old who underwent two-stage epilepsy surgeries during January 2012–2016. Invasive subdural grids were placed via craniotomy during Stage 1 and the epileptogenic zone was removed during Stage 2 of the surgery. We compared the volume of intraoperative bleeding between these two surgeries and identified variables associated with bleeding using multivariate regression analysis.Results: Both surgeries resulted in similar intraoperative bleeding (24 vs. 26 ml/kg, P = 0.835), but Stage 2 required greater volumes of blood transfusion than Stage 1 (18.4 vs. 14.8 ml/kg, P = 0.011). Massive bleeding was associated with patients < 7 years old in Stage 1 and weighing < 18 kg in Stage 2.Conclusions: The volume of intraoperative bleeding was similar between the two stages of pediatric epilepsy surgery and was large enough to require blood transfusions. Thus, blood loss during pediatric epilepsy surgery occurred at both anatomic sites. This indicates the necessity of early preparation for blood transfusion in both stages of pediatric epilepsy surgery.

Background and Objectives: Robot-assisted direct-to-implant breast reconstruction involves procedural factors that may affect intraoperative hemodynamics, including prolonged surgery, semi-sitting positioning, and subcutaneous carbon dioxide insufflation. This study compared vasopressor requirements and hemodynamic profiles between remimazolam-based total intravenous anesthesia (TIVA) and propofol–sevoflurane anesthesia. Materials and Methods: This retrospective cohort study included 46 patients who underwent robot-assisted direct-to-implant breast reconstruction. Of these, 20 received propofol–sevoflurane anesthesia, and 26 received remimazolam-based TIVA. The primary outcome was total intraoperative norepinephrine consumption. Secondary outcomes included vasopressor infusion duration, time from induction to vasopressor initiation, incidence of hypotension, hemodynamic profiles analyzed using linear mixed-effects models, postoperative pain scores, and reconstructive outcomes. Results: Total norepinephrine consumption was significantly lower in the remimazolam group than in the propofol–sevoflurane group (median, 123.2 [interquartile range, 62.4–176.4] vs. 580.0 [338.8–790.4] µg; p < 0.001). The remimazolam group also had a shorter vasopressor infusion duration (67.7 ± 40.0 vs. 176.3 ± 66.4 min; p < 0.001), a longer vasopressor-free interval from induction (median, 140 vs. 25 min; log-rank p < 0.001), and a lower incidence of hypotension, defined as mean arterial pressure (MAP) < 65 mmHg (46.2% vs. 80.0%; p = 0.032). After adjustment for age, body mass index, and anesthesia time, remimazolam-based anesthesia remained associated with lower norepinephrine consumption (B = −515.4 µg; p < 0.001). MAP and heart rate (HR) showed no significant between-group differences over time, and neither the estimated duration nor time-weighted average (TWA) below MAP 65 mmHg differed significantly. Conclusions: In this retrospective cohort, a remimazolam-based TIVA strategy was associated with lower recorded intraoperative norepinephrine use than a propofol–sevoflurane strategy. No significant between-group differences in serial MAP or HR were detected. These associations warrant confirmation in prospective trials with standardized protocols.