Arterial Cord Research Articles

Leiomyoma of the umbilical cord artery: A case report

Leiomyoma of the umbilical cord artery: A case report

Placental abruption with certified fetomaternal hemorrhage after traffic injury

We report a case of patients with placental abruption which certified fetomaternal hemorrhage (FMH) after traffic injury. A 21-year-old multipara was admitted to private clinic after traffic accident on 29th week gestation. Cardiotocogram (CTG) showed sinusoidal-like pattern with tachycardia and she was transferred to our hospital. Her injury was also not severe, but due to abnormal CTG suggesting massive FMH, immediate cesarean section was performed. The infant was saved with the umbilical cord artery blood pH=7.243, and a maternal good postoperative course was observed. FMH was proved by maternal serum concentrations of hemoglobin F and alpha fetoprotein. Language: en

New evaluation of fetal oxidative stress: measurement of the umbilical cord blood dimethyl sulfate-induced ascorbyl-free radical by an electron spin resonance method

Objective: The aim is to evaluate intrapartum fetal oxidative stress in real-time by umbilical cord blood dimethyl sulfate (DMSO)-induced ascorbyl-free radical (AFR) measured by an electron spin resonance (ESR) method.Methods: Seventy-five mothers delivering at gestational age after 37 weeks were recruited. They were divided into three groups: spontaneous vaginal birth (n = 27), elective cesarean section (CS) (n = 34), and emergency CS due to non-reassuring fetal status (n = 14). Umbilical artery (UA) and venous (UV) cord blood gas analysis was performed. Serum levels of DMSO-induced AFR (AFR/DMSO) that reflect vitamin C concentrations were measured by ESR spectroscopy.Results: Blood gas analysis showed no significant differences among the groups. UA-AFR/DMSO level of elective CS group was significantly lower compared with spontaneous delivery group (0.32 ± 0.12 versus 0.46 ± 0.14, p < 0.005). Emergency CS group showed significantly lower levels of UA-AFR/DMSO compared with elective CS group (0.25 ± 0.11 versus 0.32 ± 0.12, p < 0.005). UV-AFR/DMSO levels had no significant difference among the groups.Conclusions: It is suggested that fetal cord blood AFR/DMSO is a sensitive marker to assess fetal oxidative stress during delivery.

Tissue-engineered fibrin-based heart valve with a tubular leaflet design.

The general approach in heart valve tissue engineering is to mimic the shape of the native valve in the attempt to recreate the natural haemodynamics. In this article, we report the fabrication of the first tissue-engineered heart valve (TEHV) based on a tubular leaflet design, where the function of the leaflets of semilunar heart valves is performed by a simple tubular construct sutured along a circumferential line at the root and at three single points at the sinotubular junction. The tubular design is a recent development in pericardial (nonviable) bioprostheses, which has attracted interest because of the simplicity of the construction and the reliability of the implantation technique. Here we push the potential of the concept further from the fabrication and material point of view to realize the tube-in-tube valve: an autologous, living HV with remodelling and growing capability, physiological haemocompatibility, simple to construct and fast to implant. We developed two different fabrication/conditioning procedures and produced fibrin-based constructs embedding cells from the ovine umbilical cord artery according to the two different approaches. Tissue formation was confirmed by histology and immunohistology. The design of the tube-in-tube foresees the possibility of using a textile coscaffold (here demonstrated with a warp-knitted mesh) to achieve enhanced mechanical properties in vision of implantation in the aortic position. The tube-in-tube represents an attractive alternative to the conventional design of TEHVs aiming at reproducing the valvular geometry.

Mouse extraembryonic arterial vessels harbor precursors capable of maturing into definitive HSCs

AbstractDuring mouse development, definitive hematopoietic stem cells (dHSCs) emerge by late E10.5 to E11 in several hematopoietic sites. Of them, the aorta-gonad-mesonephros (AGM) region drew particular attention owing to its capacity to autonomously initiate and expand dHSCs in culture, indicating its key role in HSC development. The dorsal aorta contains characteristic hematopoietic clusters and is the initial site of dHSC emergence, where they mature through vascular endothelial (VE)-cadherin+CD45–CD41low (type 1 pre-HSCs) and VE-cadherin+CD45+ (type 2 pre-HSCs) intermediates. Although dHSCs were also found in other embryonic niches (placenta, yolk sac, and extraembryonic vessels), attempts to detect their HSC initiating potential have been unsuccessful to date. Extraembryonic arterial vessels contain hematopoietic clusters, suggesting that they develop HSCs, but functional evidence for this has been lacking. Here we show that umbilical cord and vitelline arteries (VAs), but not veins, contain pre-HSCs capable of maturing into dHSCs in the presence of exogenous interleukin 3, although in fewer numbers than the AGM region, and that pre-HSC activity in VAs increases with proximity to the embryo proper. Our functional data strongly suggest that extraembryonic arteries can actively contribute to adult hematopoiesis.

Influence of fetal birth weight on perinatal outcome in planned vaginal births

The aim of this study was to provide information for better obstetric counseling by analyzing the impact of fetal birth weight (BW) on fetal and maternal outcome when vaginal birth is planned in a university hospital. In this retrospective study from January 1st 2006 to December 31st 2011, 5,177 singleton, alive deliveries at or >37 gestational weeks were assessed with regard to the fetal BW when vaginal birth was attempted. The normal BW group was defined as ≥2,500 <4,500 g. For comparison, further BW groups were defined as: group 1 <2,500 g, group 2 ≥4,000 <4,250 g, group 3 ≥4,250 <4,500 g and group 4 ≥4,500 g. Outcome criteria were mode of delivery and perineal lacerations as well as the pH and base excess of the umbilical cord artery, the Apgar score after 5 min and occurrence of shoulder dystocia. The set of controlling variables included maternal height, maternal weight, maternal age, gestational age, neonatal sex and parity. Second stage caesarean section is significantly more likely when fetal BW is under 2,500 g (30.7 vs. 15.5 % in the normal BW group, odds ratio 3.01, 95 % confidence interval 2.03-4.46, p value < 0.001). Shoulder dystocia occurred significantly more often when fetal BW was over 4,250 g (group 3: odds ratio 4.95, 95 % confidence interval 1.74-14.10, p value 0.003, group 4: odds ratio 19.96, 95 % confidence interval 7.61-52.38, p value < 0.001). The risk of an Apgar score after 5 min below 7 increased, when fetal BW was below 2,500 g (odds ratio 9.28, 95 % confidence interval 3.15-27.35, p value < 0.001) or above 4,500 g (odds ratio 5.65, 95 % confidence interval 1.22-26.24, p value 0.027). All groups were comparable to the normal group regarding pH and base excess of the umbilical cord artery as well as the risk for severe (third and fourth degree) perineal lacerations. Although a fetal birth weight under 2,500 g and a birth weight over 4,250 g are associated with some risks, there is no general contraindication for an attempt to deliver vaginally in a university hospital with regard to fetal birth weight.

Catheter-over-needle method facilitates effective continuous infraclavicular block

To the Editor, We read with great interest the excellent article written by Dr. Lecours et al. which reported an observational cohort study of all ultrasound-guided single-injection infraclavicular blocks (ICBs) performed over a two-year period at their institution. The authors observed that ultrasound-guided ICB performed with a single injection posterior to the axillary artery is a reasonably safe technique associated with a high success rate regardless of the expertise of the anesthesiologist performing the block. Experience within our institution is consistent with this observation, and we would agree strongly that ICB performed by single injection posterior to the axillary artery is safe and effective. Further, this provides an excellent approach for placement of a continuous catheter using a catheter-over-needle technique. Here, with written consent from the patient, we report our recent experience of placing an infraclavicular catheter utilizing a 21G 9 95-mm catheter-over-needle unit (MultiSet UPK NanoLine 21156-40E, Pajunk, Germany) for a planned re-implantation of thumb after a rope-related farming accident. A high-frequency linear ultrasound transducer (13-6 MHz HFL38, M-Turbo ; SonoSite, Bothell, WA, USA) was placed in the deltopectoral grove parasagittally, where the axillary artery and the lateral cord of brachial plexus in its lateral aspect were easily identified (Figure). After raising a local anesthetic wheal, the catheter-over-needle unit was inserted cephalad to the probe and advanced in-plane caudally or inferiorly at approximately 45 to 60 from the ultrasound probe axis, through the pectoral muscles and toward the parasagittal plane between the axillary artery and the lateral cord. Hydrodissection with dextrose 5% in water was used to create sufficient space between the lateral cord and axillary artery to advance the needle/catheter unit into a more advantageous position, posterior to the axillary artery and directly adjacent to the posterior cord. Once the tip of the needle was positioned, and, following negative aspiration of blood or air, 20 mL of local anesthetic was injected to open the perivascular space. The needle was removed from the outer catheter, and a flexible, 20G 9 75-mm inner catheter was inserted through the cannula and Luer-locked onto the 18G catheter sheath such that both catheters were in situ. Before securing the catheter in place with a dressing (e.g., Tegaderm), a further 10 mL of local anesthetic was injected through the catheter to complete the block and confirm the spread. Instead of the planned thumb reimplantation, debridement of the thumb was performed. In the post anesthetic recovery room, a local anesthetic infusion was commenced and continued at 1 mL hr with an 8 mL bolus every hour until the next morning when the infraclavicular catheter was removed and the patient transitioned to oral analgesia. Throughout the infusion, the patient was pain-free, and the catheter remained in place with intact and dry dressings, as was our experience with an interscalene catheter placed using the catheterover-needle method. We have used this approach to place five infraclavicular catheters over the last three months, and in each case, the pain management was excellent. Catheter insertion has been uncomplicated and all have been removed as planned. Editor’s Note: The authors of the article: Can J Anesth 2013; 60: 244-52, respectfully declined an invitation to submit a reply to the above Letter to the Editor.

Large Scale Expansion of Human Umbilical Cord Cells in a Rotating Bed System Bioreactor for Cardiovascular Tissue Engineering Applications

Widespread use of human umbilical cord cells for cardiovascular tissue engineering requires production of large numbers of well-characterized cells under controlled conditions. In current research projects, the expansion of cells to be used to create a tissue construct is usually performed in static cell culture systems which are, however, often not satisfactory due to limitations in nutrient and oxygen supply. To overcome these limitations dynamic cell expansion in bioreactor systems under controllable conditions could be an important tool providing continuous perfusion for the generation of large numbers of viable pre-conditioned cells in a short time period. For this purpose cells derived from human umbilical cord arteries were expanded in a rotating bed system bioreactor for up to 9 days. For a comparative study, cells were cultivated under static conditions in standard culture devices.Our results demonstrated that the microenvironment in the perfusion bioreactor was more favorable than that of the standard cell culture flasks. Data suggested that cells in the bioreactor expanded 39 fold (38.7 ± 6.1 fold) in comparison to statically cultured cells (31.8 ± 3.0 fold). Large-scale production of cells in the bioreactor resulted in more than 3 x 108 cells from a single umbilical cord fragment within 9 days. Furthermore cell doubling time was lower in the bioreactor system and production of extracellular matrix components was higher. With this study, we present an appropriate method to expand human umbilical cord artery derived cells with high cellular proliferation rates in a well-defined bioreactor system under GMP conditions.

Contraindications for External Cephalic Version in Breech Position at Term

External cephalic version (ECV) is often recommended to avoid a cesarean delivery (CD) in women with a fetus in the breech position. International guidelines recommend that all women with an uncomplicated breech pregnancy at term should be offered an ECV. These guidelines also list contraindications to ECV; however, excluding patients from ECV in the presence of only 1 clinical factor that could affect its success rate is undesirable. This systematic review was performed to determine whether the contraindications to ECV in guidelines are consistent and based on empirical data and to offer recommendations for ECV contraindications. Guidelines and databases were identified and searched for studies reporting on ECV and citing contraindications. All studies reporting on ECV in a singleton pregnancy from 36 weeks without a contraindication for vaginal delivery were selected. Contraindications were categorized as maternal, fetal, and other factors. The electronic search for guidelines found 5 sets that reported on 18 contraindications, with 5 to 13 contraindications per guideline. The literature search provided 890 studies on ECV; of 261 retrieved, 60 articles were assessed and reported on 39 different contraindications to ECV. Forty-three studies were cohort studies, 6 were case-control studies, and 11 were randomized controlled trials. The 39 contraindications were separated into 3 categories. Maternal factors included uterine anomaly, preeclampsia/hypertension, ruptured membranes, antepartum or second-trimester bleeding, abruptio placentae in history, active labor, cardiac disease, obesity, electrocardiogram abnormalities, abnormal pelvis, age older than 45 years, allergies, CD in history, diabetes, dilated cervix, grand multipara, hyperthyroidism, and irregular T4. The fetal factors were growth restriction, abnormal cardiotocography, fetal anomaly, macrosomia, hyperextension of head, unstable lie, Doppler abnormalities, fetal distress, positive nonstress test, Rhesus immunization, and uteroplacental transfusion. Other factors included oligohydramnios, restrictive nuchal cord, inexperienced obstetrician, anterior placenta, polyhydramnios, and single umbilical artery. For each contraindication, the literature was searched to determine whether it was an evidence-based contraindication. Studies reporting on breech presentation in a woman with a previous CD or with premature rupture of the membranes indicated that an ECV attempt was possible and could be successful. Evidence was not found for other maternal factors as contraindications, and the present authors concluded that the main risk factors are based on clinical physiologic knowledge. No studies reported on the relationship between ECV and placental abruption, but it is a rare complication of ECV. Considering the seriousness of the complication and the higher risk of recurrence in patients with a history of placental abruption, ECV should be withheld in patients suspected of an imminent or history of abruption. One meta-analysis examined the relationship between the success rate of ECV and estimated fetal weight. No adverse events were reported for small-for-gestational age fetuses, but the evidence was insufficient to conclude that ECV is safe in cases of severe growth restriction with Doppler abnormalities. Three reviews reported on the relationship between success rates of ECV and oligohydramnios and concluded that an amniotic fluid index greater than 10 cm was associated with an increased chance of success, but these studies did not report any adverse events of ECV in women with a low amniotic fluid index. One review reported the relationship between anterior placenta and a lower success rate of ECV, but in none of the studies were complications reported. Oligohydramnios was the only contraindication mentioned in all guidelines. Of the 39 contraindications to ECV mentioned in the guidelines and literature, evidence could be assessed for only 6. The adherence to contraindications that were not well defined indicates that ECV may be withheld from a high proportion of women who could benefit from the procedure without increased risks of adverse events. The authors propose 3 contraindications to ECV. Maternal contraindications are placental abruption in history or signs of this complication and severe preeclampsia or HELLP syndrome (both level III evidence); fetal factors are signs of fetal distress, that is, abnormal cardiotocography or abnormal Doppler flow or both (level III evidence). Contraindications to ECV should be limited to those with clear empirical evidence or to factors with a clear pathophysiologic relevance.

Serum silicon concentrations in pregnant women and newborn babies

Earlier studies in animals have suggested an essential role for Si in connective tissues, but such works have not been replicated per se. Nonetheless, a study conducted in 2000 has reported that Si may be essential during pregnancy for the growing fetus, since serum Si concentrations in infants were approximately 300% higher than those in older children and adults and serum Si concentrations in pregnant women were approximately 300% lower than those in age-matched non-pregnant controls. To reproduce these potentially important findings, in the present study, serum Si concentrations were measured in fourteen pregnant women (15-24 weeks of gestation) and compared with those of seventeen non-pregnant, non-lactating female controls. Serum Si concentrations were also measured in fourteen full-term mothers at the time of delivery and in the umbilical cord (UC) vein and artery where possible. Fasting serum Si concentrations in pregnant women were not significantly different from those of the female controls and showed little change with advancing gestation (r 0·2). Mean serum Si concentrations in the UC vein samples were 52% higher, while those in the UC artery samples were 235% higher than those in the maternal forearm vein samples, although data were widely spread and differences were not significant. Mean maternal forearm vein Si concentrations at delivery were 50% lower than those of pregnant women and female controls, but, again, these were not significant. Overall, we note that there are significant analytical challenges in comparing baseline Si levels between different groups; notwithstanding, our findings cannot confirm a reduction in fasting serum Si levels during pregnancy, but, equally, we cannot rule out higher serum Si levels in newborns than in their mothers, and further work is required.

Adverse obstetrical and neonatal outcomes in elective and medically indicated inductions of labor at term

Objective: To compare the adverse neonatal and maternal outcomes after medically indicated and elective labor induction. Both induction groups were also compared to women with spontaneous onset of labor.Method: Retrospective cohort study of 13 971 women with live, cephalic singleton pregnancies who delivered at term (from 1997 to 2007). Adverse maternal and neonatal outcomes were compared between women who underwent an induction of labor in the presence and absence of standard medical indications.Results: Among 5090 patients with induced labor, 2059 (40.5%) underwent elective labor inductions, defined as inductions without any medical or obstetrical indication. Risks of cesarean or instrumental delivery, postpartum hemorrhage >500 ml, prolonged maternal hospitalization >6 days, Apgar<7 at 5 min of life, arterial umbilical cord pH<7.1, admission in neonatal intensive care unit (NICU) and prolonged NICU hospitalization >7 days were similar between nulliparous who underwent elective and medical labor induction. Similar results were obtained for multiparous. All the above mentioned risks, but the Apgar<7 at 5 min of life, were significantly increased after induction in comparison to spontaneous labor.Conclusion: Elective induction of labor carries similar obstetrical and neonatal risks as a medically indicated labor induction. Thus, elective induction of labor should be strongly discouraged.

Abstract 290: Microrna-199a and Glut1 are Differentially Expressed in Primary Human Arterial and Venous Endothelium and are Deregulated in Culture

Introduction Studies over the last decade have established that the identity of arterial and venous endothelial cells (ECs) is governed by both genetic and environmental factors. Although the ephrin/Eph system is known to be a key determinant of that identity, it is unlikely that system is solely responsible for all the differences between arterial and venous ECs. Furthermore, microRNAs are becoming increasingly recognized for their important role in regulating gene expression and cell fate. We investigate here novel potential markers and regulators of arterial EC identity and the effects of environmental cues on these molecules. Methods ECs were freed from the basement membrane of human umbilical arteries and veins (HUAECs, HUVECs) (n=6) by enzymatic digestion and purified by flow cytometry (CD31+, CD45-) prior to lysis and quantitative PCR or analysis using HPLC-MS/MS. Protein quantification was performed using a proprietary software package (IdentiQuantXL TM ). HUVECs and HUAECs were harvested directly from umbilical cords and placed directly into collagen coated 6-well plates and cultured in standard conditions in EGM2. Results We found that microRNA-199a levels were 23 fold higher in HUVECs than HUAECs (p=0.0001). One of microRNA-199a’s theoretical downstream targets is GLUT1, a facilitative glucose transporter thought to be responsible for basal glucose uptake. GLUT1 mRNA and protein levels were significantly higher (5.5 and 4.3 fold, respectively) in HUAEC than HUVECs (p=0.00002). Using tissue immunohistochemistry (IHC) of we confirmed that GLUT1 expression is restricted to arterial ECs in human umbilical cord and adult peripheral artery and vein sections. Finally, GLUT1 mRNA levels are 2 fold higher in HUAECs than HUVECs in culture at P2 and levels decrease until P5 when they become equal indicating that culture has a homogenizing effect on endothelial heterogeneity. Conclusions MicroRNA-199a levels are higher in HUVECs than HUAECs and GLUT1, its downstream target, is higher in HUAECs both at the mRNA and protein level. Protein expression is restricted to arteries in both the new born umbilical cord and adult peripheral vessels. Importantly, expression in both cell types is downregulated and equilibrated by cell culture.

PL.12 Short Term Clinical Outcomes of Neonates with Severe Perinatal Acidosis: A Prospective Study

Background Therapeutic hypothermia improves outcomes for asphyxiated infants, however not all infants born with severe acidosis are assessed as eligible for cooling and few data describe short-term clinical outcomes for...

Association between umbilical cord artery pCO2 and the Apgar score; elevated levels of pCO2 may be beneficial for neonatal vitality after moderate acidemia

To determine the association between 5-min Apgar score and umbilical cord artery carbon dioxide tension (pCO₂). Observational study. European hospital labor wards. Data from 36,432 newborns ≥36 gestational weeks were obtained from three sources: two trials of monitoring with fetal electrocardiogram (the Swedish randomized controlled trial and the European Union Fetal ECG trial) and Mölndal Hospital data. After validation of the acid-base values, 25,806 5-min Apgar scores were available for analysis. Validation of the umbilical cord acid-base values was performed to obtain reliable data. 5-min Apgar score was regressed against cord artery pCO₂ in a polynomial multilevel model. Five-min Apgar score, umbilical cord pCO₂, pH, and base deficit. Overall, a higher cord artery pCO₂ was found to be associated with lower 5-min Apgar scores. However, among newborns with moderate acidemia, lower umbilical cord artery pCO₂ (≤median pCO₂ for the specific cord artery pH) was associated with lower 5-min Apgar scores, with a relative risk of 2.0 (95% confidence interval: 1.4-2.8) for 5-min Apgar scores 0-6. Metabolic acidosis affects the newborn's vitality more than respiratory acidosis. In addition, elevated levels of pCO₂ may be beneficial for fetuses with moderate acidemia, and thus cord artery pCO₂ is a factor that should be considered when assessing the compromised newborn.

Transesophageal Echocardiography

Transesophageal Echocardiography

Periarterial stem villous edema is associated with hypercoiled umbilical cord and stem obliterative endarteritis

To assess clinicopathologic correlations of a novel placental lesion featuring a distinct ring-like periarterial edema of stem villi (PASE). A retrospective case-control statistical comparison (Yates χ2 or analysis of variance) of 30 clinical and 41 placental features of 100 consecutive placentas with PASE and 100 gestational age-matched cases without PASE, extracted from 2403 placentas from high-risk pregnancies signed out by the author since year 2006. The PASE was seen in 4.2% of placentas, average gestational age 35.9 weeks (range, 24 - 42 weeks). Frequencies of stem obliterative endarteritis and hypercoiled umbilical cord (coiling index > 0.3) were 23% vs 5% (p = 0.005), and 20% vs 9% (p = 0.04) in the study group and comparative group, respectively. There were no statistically significant differences (p > 0.05) between the groups in clinical or other placental variables. The PASE may be linked to chronically abnormal blood flow in umbilical cord arteries and their stem branches and may be a histological placental sign of non-obliterative umbilical cord compromise.

750: Can we predict arterial and venous cord blood discordance?

750: Can we predict arterial and venous cord blood discordance?

Fibrin-Based Tissue Engineering: Comparison of Different Methods of Autologous Fibrinogen Isolation

This study is focussed on the optimal method of autologous fibrinogen isolation with regard to the yield and the use as a scaffold material. This is particularly relevant for pediatric patients with strictly limited volumes of blood. The following isolation methods were evaluated: cryoprecipitation, ethanol (EtOH) precipitation, ammonium sulfate [(NH(4))(2)SO(4))] precipitation, ammonium sulfate precipitation combined with cryoprecipitation, and polyethylene glycol precipitation combined with cryoprecipitation. Fibrinogen yields were quantified spectrophotometrically and by electrophoretic analyses. To test the influence of the different isolation methods on the microstructure of the fibrin gels, scanning electron microscopy (SEM) was used and the mechanical strength of the cell-free and cell-seeded fibrin gels was tested by burst strength measurements. Cytotoxicity assays were performed to analyze the effect of various fibrinogen isolation methods on proliferation, apoptosis, and necrosis. Tissue development and cell migration were analyzed in all samples using immunohistochemical techniques. The synthesis of collagen as an extracellular matrix component by human umbilical cord artery smooth muscle cells in fibrin gels was measured using hydroxyproline assay. Compared to cryoprecipitation, all other considered methods were superior in quantitative analyses, with maximum fibrinogen yields of ∼80% of total plasma fibrinogen concentration using ethanol precipitation. SEM imaging demonstrated minor differences in the gel microstructure. Ethanol-precipitated fibrin gels exhibited the best mechanical properties. None of the isolation methods had a cytotoxic effect on the cells. Collagen production was similar in all gels except those from ammonium sulfate precipitation. Histological analysis showed good cell compatibility for ethanol-precipitated gels. The results of the present study demonstrated that ethanol precipitation is a simple and effective method for isolation of fibrinogen and a suitable alternative to cryoprecipitation. This technique allows minimization of the necessary blood volume for fibrinogen isolation, particularly important for pediatric applications, and also has no negative influence on microstructure, mechanical properties, cell proliferation, or tissue development.

Neurophysiological Assessment of Thoracic and Cervical Pedicle Screw Integrity

Transpedicular instrumentation of the thoracic and cervical spine is technically more difficult than at lumbar levels because of narrower pedicles and less sensitive intraoperative fluoroscopic assessment. Furthermore, the potential implications of a misplaced screw are greater because of the close proximity of the spinal cord and vertebral artery. Real-time confirmation of correct pedicle screw placement in the operating room is therefore considered even more important, and this article reviews the availability, utility, and limitations of electrophysiologic testing techniques that can be used for this purpose.

Challenging posterior mediastinal mass resection via a minimally invasive approach with neurological monitoring†

We report a novel surgical strategy for the resection of a rare type of posterior mediastinal tumour in a young patient. A melanotic schwannoma arose from the left thoracic sympathetic chain, adjacent to the origin of the artery of Adamkiewicz. Successful excision of this tumour via a minimally invasive approach without arterial or spinal cord injury was possible with the aid of neurological monitoring using spinal-evoked potentials.