Intraoperative hemostatic agents in orbital surgery.

PURPOSE: While preoperative optimization and post-operative management of hemorrhagic complications are increasingly clear, intraoperative control of bleeding during orbital surgery has received less attention. Thanks to advances in other fields, new technologies may be employed during these interventions. This review was designed to discuss these modalities. METHODS: A literature search was performed to identify manuscripts that are related to the management of intraoperative bleeding. The bibliographies of these studies were also assessed to identify additional references. Data was abstracted from these studies. RESULTS: Multiple hemostatic agents are currently used in orbital surgery, and related surgical fields have carefully assessed these interventions. Direct mechanical, flowable, and pro-thrombotic medications may all play key roles in achieving hemostasis. CONCLUSIONS: Orbital surgeons have several potential technologies to facilitate hemostasis, and the armamentarium continues to grow. Future investigations will yield more targeted medications that may be delivered in novel manners to enhance the intraoperative experience.

Evaluation of polymeric membranes' performance during laboratory-scale experiments, regarding the CO2 separation from CH4.

The present study evaluates the separation performance of a commercially available polymeric membrane, when employed for the upgrade of biogas to enrich CH4 from a simulated binary gas mixture. For this purpose, a laboratory-scale membrane set-up device has been designed and assembled, aiming to achieve the production of high purity biomethane (>95%) with simultaneous recycling and utilization of the (considered as) waste CO2 stream. The examined membrane is a polysulfone (PSF) hollow fiber (HF) one, applied in counter-current flow. The feed concentration of gases consisted between 55-70 vol% and 45-30 vol%, regarding CH4 and CO2 respectively, whereas the effect of retentate pressure was studied in the range between 0.7 and 1.5 bars. The experimental results reveal that the concentration of CH4 in the retentate stream can exceed the target value of 95%, when the applied pressure values are above the limit of 1 bar. Any increase in the feed pressure can lead also to higher CH4 purity on the retentate side, however the retentate mass flow decreases, leading to smaller recovery values of CH4. A significant increase in the CH4 purity is observed, when the CH4 recovery drops below 40%, suggesting the need for the application of multiple membrane modules, operating in series. Regarding the CO2 concentration in the permeate stream, its percentages range between 30 and 50%, which are not considered as sufficient to permit immediate reuse, whereas the need of extra membrane modules to improve the purity of gas streams is confirmed.

How to Manage a Patient with Haemophilia and ACS Requiring PCI: A Battle between Bleeding and Thrombosis.

We present the case of a 70-year-old man with a history of haemophilia B, who presented to our hospital with a non-ST-elevation myocardial infarction. The patient, following consultation by a haemophilia expert, was revascularized with percutaneous coronary intervention (PCI) under adequate clotting factor administration. Patients with haemophilia and acute coronary syndrome, are susceptible to periprocedural bleeding and thrombotic events during PCI, and therefore a balanced management plan should always be implemented by a multidisciplinary team.

Trends in ablation procedures in Greece over the 2008-2018 period: Results from the Hellenic Cardiology Society Ablation Registry.

OBJECTIVE: In 2008, the radiofrequency ablation (RFA) procedures registry of the Hellenic Society of Cardiology was created. This online database allowed electrophysiologists around the country to input data for all performed ablation procedures. The aim of this study is to provide a thorough report and interpretation of the data submitted to the registry between 2008 and 2018. METHODS: In 2008, a total of 27 centers/medical teams in 24 hospitals were licensed to perform RFA in Greece. By 2018, the number had risen to 31. Each center was tasked with inserting their own data into the registry, which included patient demographics (anonymized), type of procedure and technique, complications, and outcomes. RESULTS: A total of 18587 procedures in 17900 patients were recorded in the period of 2008-2018. By 2018, slightly more than 70% of procedures were performed in 7 high-volume centers (>100 cases/year). The most common procedure since 2014 was atrial fibrillation ablation, followed by atrioventricular nodal reentry tachycardia ablation. Complication rates were low, and success rates remained high, whereas the 6-month relapse rates declined steadily. CONCLUSION: This online RFA registry has proved that ablation procedures in Greece have reached a very high standard, with results and complication rates comparable to European and American standards. Ablation procedures for atrial fibrillation are increasing constantly, with it being the most common intervention over the last 6-year period, although the absolute number of procedures still remains low, compared to other European countries.

Constructing bi-plots for random forest: Tutorial.

Current technological developments have allowed for a significant increase and availability of data. Consequently, this has opened enormous opportunities for the machine learning and data science field, translating into the development of new algorithms in a wide range of applications in medical, biomedical, daily-life, and national security areas. Ensemble techniques are among the pillars of the machine learning field, and they can be defined as approaches in which multiple, complex, independent/uncorrelated, predictive models are subsequently combined by either averaging or voting to yield a higher model performance. Random forest (RF), a popular ensemble method, has been successfully applied in various domains due to its ability to build predictive models with high certainty and little necessity of model optimization. RF provides both a predictive model and an estimation of the variable importance. However, the estimation of the variable importance is based on thousands of trees, and therefore, it does not specify which variable is important for which sample group. The present study demonstrates an approach based on the pseudo-sample principle that allows for construction of bi-plots (i.e. spin plots) associated with RF models. The pseudo-sample principle for RF. is explained and demonstrated by using two simulated datasets, and three different types of real data, which include political sciences, food chemistry and the human microbiome data. The pseudo-sample bi-plots, associated with RF and its unsupervised version, allow for a versatile visualization of multivariate models, and the variable importance and the relation among them.

The role of catheter ablation in the management of patients with implantable cardioverter defibrillators presenting with electrical storm.

OBJECTIVE: Electrical storm (ES) is not uncommon among patients with an implantable cardioverter defibrillator (ICD) in situ. Catheter ablation (CA) may suppress the arrhythmia in the acute setting and prevent ES recurrence. METHODS: Nineteen consecutive patients with an ICD in situ presenting with ES underwent electrophysiologic studies followed by CA. CA outcome was classified as a complete success if both clinical and non-clinical tachycardia were successfully ablated, partial success if ≥1 non-clinical tachycardia episodes were still inducible post-CA, and failure if clinical tachycardia could not be abolished. Patients were followed for a median period (IQR) of 5.6 (1.8-13.7) months. The primary endpoint was event-free survival from ES recurrence. The secondary endpoint was event-free survival from a composite of ES and/or sustained ventricular tachycardia (VT) recurrence. RESULTS: Clinical arrhythmia was successfully ablated in 14 out of 19 (73.7%) cases after a single CA procedure. A completely successful CA outcome was associated with significantly increased ES-free survival compared with a partially successful or failed procedure (Log rank P=0.039). Nevertheless, patients with acute suppression of all tachycardia episodes (n=11), relative to those with a partially successful or a failed CA procedure (n=8), did not differ in incidence of the composite endpoint of sustained VT or ES (Log rank P=0.278). CONCLUSION: A single CA procedure can acutely suppress clinical arrhythmia in three-quarters of cases. A completely successful CA outcome can prolong ES-free survival; however, sporadic ICD therapies cannot be abrogated.

Left Ventricular Pacing through Coronary Sinus Is Feasible and Safe for Patients with Prior Tricuspid Valve Intervention.

BACKGROUND: In the presence of tricuspid valve intervention, right ventricular lead implantation is associated with the potential risk of tricuspid valve malfunction leading to a tricuspid regurgitation. Few cases have been reported with successful left ventricular pacing via the coronary sinus (CS) after tricuspid valve replacement or repair. In this retrospective study, we present the long-term clinical outcomes of 17 patients who underwent CS lead implantation and left ventricular pacing. METHODS: Seventeen consecutive patients referred to our institution with an indication of postprocedural pacemaker (PM) implantation after tricuspid valve intervention were retrospectively included in the study. The indication for device implantation in all patients was atrial fibrillation with a symptomatic pause ≥ 3.0 seconds. Thus, all devices implanted were ventricular rate responsive (VVIR). RESULTS: All device implantations were successful and uncomplicated. Mean operation time was 60 ± 8 minutes. Mean fluoroscopy time was 8.3 ± 2.1 minutes. Mean R-wave sensing was 7.5 ± 2.0 mV with a mean slew rate of 2.2 V/s. A mean pacing threshold of 1.9 ± 0.3 V/0.4 ms was accepted as patients were not PM-dependent. The pacing impedance was 743.5 ± 109.71 Ohm. At 2-year follow-up, pacing sensing, threshold, and impedance values were unchanged and no lead dislodgement has been noted. CONCLUSIONS: In patients with tricuspid valve intervention, left ventricular pacing might be the treatment of choice for permanent ventricular pacing, with all the advantages of the endovenous route as a minimally invasive approach.

Transvenous extraction of cardiac rhythm device leads: a report of the experience from a single referral centre in Greece.

INTRODUCTION: As rates of implanted cardiac electronic devices continue to rise, lead extraction procedures are crucial for the management of complications. The optimal method for such procedures has been constantly debated. We sought to review our experience of lead extraction using a conventional technique. METHODS: This was a retrospective study of lead extraction procedures in a major referral centre in Greece. Leads were extracted in a series of 66 consecutive patients (69% men, age range 53-90 years) who visited our centre between August 2008 and June 2012. The extraction procedure was performed in the catheterization lab with a widely used system composed of a locking stylet and sheath. RESULTS: A total of 120 leads were extracted (51 atrial, 69 ventricular) including 19 defibrillator leads and 9 coronary sinus leads. The most frequent indication for lead extraction was infective endocarditis (28 patients, 42%), followed by generator pocket infection (22 patients, 33%), and lead malfunction (16 patients, 24%). Extraction was achieved through the venous entry-site approach in all procedures. The leads were completely extracted in 65 patients (98.5%). Only one complication was recorded: perforation of the right atrium in one patient (1.5%), who eventually underwent emergency cardiac surgery with a good outcome. CONCLUSIONS: Our data confirm that a conventional mechanical technique is highly effective for successful extraction of all types of implanted cardiac electronic device leads and is associated with very limited complications.

Quinidine: an "endangered species" drug appropriate for management of electrical storm in brugada syndrome.

Brugada syndrome is an inherited channelopathy associated with an increased risk of syncope and sudden cardiac death. In rare cases it can be manifested with electrical storm. We report two cases of Brugada syndrome that presented with electrical storm and were treated successfully with oral quinidine, an "endangered species" drug.

Tetravalent manganese feroxyhyte: a novel nanoadsorbent equally selective for As(III) and As(V) removal from drinking water.

The development of a single-phase Fe/Mn oxy-hydroxide (δ-Fe0.76Mn0.24OOH), highly efficient at adsorbing both As(III) and As(V), is reported. Its synthesis involves the coprecipitation of FeSO4 and KMnO4 in a kilogram-scale continuous process, in acidic and strongly oxidizing environments. The produced material was identified as a manganese feroxyhyte in which tetravalent manganese is homogeneously distributed into the crystal unit, whereas a second-order hollow spherical morphology is favored. According to this structuration, the oxy-hydroxide maintains the high adsorption capacity for As(V) of a single Fe oxy-hydroxide combined with enhanced As(III) removal based on the oxidizing mediation of Mn(IV). Ion-exchange between arsenic species and sulfates as well as the strongly positive surface charge further facilitate arsenic adsorption. Batch adsorption tests performed in natural-like water indicate that Mn(IV)-feroxyhyte can remove 11.7 µg As(V)/mg and 6.7 µg As(III)/mg at equilibrium pH 7, before residual concentration overcomes the regulation limit of 10 µg As/L for drinking water. The improved efficiency of this material, its low cost, and the possibility for scaling-up its production to industry indicate the high practical impact and environmental importance of this novel adsorbent.

Large left atrial myxoma in an oligosymptomatic young woman.

We present the case of a young female with a large sporadic left atrial myxoma. Interestingly, despite the tumor's large size, this patient had only mild exertional dyspnea without any embolic events or constitutional symptoms.

Kilogram-scale synthesis of iron oxy-hydroxides with improved arsenic removal capacity: study of Fe(II) oxidation--precipitation parameters.

Various iron oxy-hydroxides were synthesized in a continuous flow kilogram-scale production reactor through the precipitation of FeSO(4) and FeCl(2) in the pH range 3-12 under intense oxidative conditions to serve as arsenic adsorbents. The selection of the optimum adsorbent and the corresponding conditions of the synthesis was based not only on its maximum As(III) and As(V) adsorption capacity but also on its potential efficiency to achieve the arsenic health regulation limit in NSF challenge water. As a result, the adsorbent prepared at pH 4, which consists of schwertmannite, was selected because it exhibited the highest adsorption capacity of 13 µg As(V)/mg, while maintaining a residual arsenic concentration of 10 µg/L at an equilibrium pH 7. The high surface charge and the activation of an ion-exchange mechanism between SO(4)(2-) adsorbed in the Stern layer and arsenate ions were found to significantly contribute to the increased adsorption capacity. Adsorption capacity values observed in rapid scale column experiments illustrate the improved efficiency of the qualified adsorbent compared to the common commercial arsenic adsorbents.

Laparoscopic repair of giant paraesophageal hernia with synthetic mesh: 45 consecutive cases.

Giant paraesophageal hernias (PEHs) are associated with progression of symptoms in up to 45 per cent of patients. Recently, many series have reported that laparoscopic repair of PEH is technically feasible, effective, and safe. A retrospective review of the University of Athens tertiary care hospitals patient database and the patient medical records identified 45 patients who underwent elective repair of a giant PEH between 2002 and 2009. Elective laparoscopic repair of a giant PEH was attempted in 45 patients who were treated with Gore-Tex dual mesh with or without Nissen fundoplication. They all had a mesh repair. Intraoperative complications included one pulmonary embolism and one recurrent hernia. The use of a mesh seems to be effective in the treatment of large hernias. It appears to offer the benefit of a shorter hospital stay and a quicker recovery.

Novel non-invasive P wave analysis for the prediction of paroxysmal atrial fibrillation recurrences in patients without structural heart disease: a prospective pilot study.

OBJECTIVES: The pathogenetic mechanisms responsible for the initiation and recurrence of PAF are not fully elucidated and vary among individuals. We evaluated the ability of a novel non-invasive approach based on P wave wavelet analysis to predict symptomatic paroxysmal atrial fibrillation (PAF) recurrences in individuals without structural heart disease. METHODS: We studied 50 patients (24 males, mean age 54.9 ± 9.8 years) presented to our emergency department with a symptomatic episode of PAF. The patients were followed-up for 12.1 ± 0.1 months and classified into two groups according to the number of PAF episodes: Group A (<5 PAF, n = 33), Group B (≥ 5 PAF, n = 17). A third Group of 50 healthy individuals without history of PAF was used as control. Study groups underwent echocardiography and orthogonal ECG-based wavelet analyses of P waves at baseline and follow-up. Maximum and mean P wave energies were calculated in each subject at each orthogonal lead using the Morlet wavelet analysis. RESULTS: Larger P wave energies at X lead and relatively larger left atrium were independently associated with >5 PAF episodes vs. <5 PAF episodes. No difference in P wave duration was detected between Groups A and B (p > 0.1), whereas Group A and B patients had longer P waves at Z lead compared to Group C (86.4 ± 13 vs. 71.5 ± 15 msec, p < 0.001). CONCLUSIONS: P wave wavelet analysis can reliably predict the generation and recurrence of PAF within a year. P wave wavelet analysis could contribute to the early identification of patients at risk for increased number of PAF recurrences.

A survey of dumping symptomatology after gastric bypass with or without lesser omental transection.

BACKGROUND: Lesser omental transection during gastric bypass for morbid obesity may be associated with postoperative dumping. A survey of postoperative symptoms was performed in patients undergoing laparoscopic Roux-en-Y gastric bypass with transection vs. preservation of the lesser omentum. METHODS: A written questionnaire on dumping symptoms was administered to patients 2 years after laparoscopic Roux-en-Y gastric bypass with or without transection of the lesser omentum. Statistical testing was performed to determine whether the rate of various symptoms was related to the transection of the lesser omentum. RESULTS: The patients without lesser omental transection had significantly less symptoms than the patients with transection for 11 out of the 17 symptoms that were queried (p < 0.05). Ingestion of sweets was associated with dumping symptoms more frequently in the group of transected patients, and this group also had a lower frequency of sweet eating (p < 0.05). CONCLUSION: This study demonstrated that transection of the lesser omentum during laparoscopic-gastric bypass was associated with more postoperative dumping symptoms compared to bypass with preservation of the lesser omentum. This association may be secondary to a partial vagotomy that may occur if the lesser omentum is transected during gastric bypass.

Preparation of activated carbons from agricultural residues for pesticide adsorption.

Activated carbons (ACs) can be used not only for liquid but also for vapour phase applications, such as water treatment, deodorisation, gas purification and air treatment. In the present study, activated carbons produced from agricultural residues (olive kernel, corn cobs, rapeseed stalks and soya stalks) via physical steam activation were tested for the removal of Bromopropylate (BP) from water. For the characterization of the activated carbons ICP, SEM, FTIR and XRD analyses were performed. Adsorption kinetics and equilibrium isotherms were investigated for all biomass activated carbons in aqueous solutions. Experimental data of BP adsorption have fitted best to the pseudo 2nd-order kinetic model and Langmuir isotherm. The study resulted that corn cobs showed better adsorption capacity than the other biomass ACs. Comparison among ACs from biomass and commercial ones (F400 and Norit GL50) revealed that the first can be equally effective for the removal of BP from water with the latter.