Discover and publish cutting edge, open research.

Browse 11,065 multi-disciplinary research preprints

Most recent

Frank van Haren

and 28 more

Objectives: To externally validate and compare Resorlu-Unsal stone score(RUSS), modified Seoul National University Renal Stone Complexity Score(S-ReSC), Ito’s nomogram and R.I.R.S. scoring systems for predicting capabilities of both the stone-free status and complications in a multi-institutional study. Materials and Methods: We performed a retrospective analysis of 949 patients who were underwent flexible ureterorenoscopy (f-URS) and laser lithotripsy for renal stones in two institutions between March-2015 and June-2020. The RUSS, modified S-ReSC, Ito’s nomogram and R.I.R.S. scores were calculated for each patient by same surgeon on imaging methods. Results were compared for their predictive capability of stone-free status and complications. Results: Of 949 patients 603 were male and 346 were female with a mean age of 47.2±14.3 (range 2-84years). Mean stone burden was 102.6±42.2 (48-270mm2). All nomograms predicted stone-free status (AUC were 0.689, 0.657, 0.303 and 0.690, respectively). All four scoring systems predicted complications with AUC values of 0.689, 0.646, 0.286 and 0.664 for RUSS, modified S-ReSC, Ito’s nomogram, R.I.R.S., respectively. Although all scoring systems were able to predict complications only Ito’s nomogram was able to predict Clavien ≥2 complications. Conclusion: All four scoring systems (RUSS, modified S-ReSC, Ito’s nomogram and R.I.R.S.) could predict stone-free status after f-URS, however the AUC values are not satisfactory in our large patient cohort. Although these scoring systems were not developed for predicting post-operative complications, they were associated with complications in our study. However, these four scoring systems have some significant limitations. The ideal scoring system is yet to be developed.

Onder Cinar

and 11 more

Abstract Aims of the study: The aim of this study was to investigate the impact of testosterone deficiency on cognitive functions in metastatic prostate cancer patients receiving androgen deprivation therapy (ADT). Methods: In this multicentric prospective study, 65 metastatic prostate cancer patients were evaluated. Demographic and clinical data were recorded. Cognitive functions were assessed using the Symbol Digit Modalities Test, the California Verbal Learning Test Second Edition, the Brief Visuospatial Memory Test - Revised, and the Trail Making Test. Depressive symptoms were assessed using the Beck Depression Inventory. Cognitive functions and depressive symptoms were recorded before the androgen deprivation therapy and at the 3- and 6-month follow ups. Results: At the basal cognitive assessment, the mean Symbol Digit Modalities Test, the California Verbal Learning Test Second Edition, the Brief Visuospatial Memory Test - Revised scores were 25.84 ± 17.54, 32.68 ± 10.60, and 17.63 ± 11.23, respectively, and the mean time for the Trail Making Test was 221.56 ± 92.44 s., and were similar at the 3-month, and 6-month controls (p > 0.05). The mean pretreatment, third and sixth month testosterone levels were 381.40 ± 157.53 ng/dL, 21.61 ± 9.09 ng/dL, and 12.25 ± 6.45 ng/dL (p < 0.05), and the total PSA levels were 46.46 ± 37.83 ng/mL, 1.41 ± 3.31 ng/mL, and 0.08 ± 0.14 ng/mL (p < 0.05), respectively. Conclusion: The ADT in patients with metastatic prostate cancer does not affect patients’ cognitive functions and depressive symptoms. However, further prospective randomized studies with higher cohorts and longer follow up periods are needed.

Chi Ying Simon Chow

and 7 more

Background and aim of the study The Valiant NavionTM stent graft system is a third-generation low profile thoracic endograft designed for thoracic endovascular aortic repair. In this population analysis, we report on the first Asian all-comers experience and outcomes who underwent thoracic endovascular aortic repair with the use of this new stent graft system. Methods Between May 2019 and October 2020, 21 patients with different aortic pathologies were prospectively recruited and retrospectively analyzed. Important clinical and device-related outcomes were evaluated. The endpoints included short-term survival, technical success, access failures, major vascular and clinical complications, endoleaks, and hospital stay. Results The commonest indication of stenting was penetrating aortic ulcers (28.6%) and 6 (28.6%) patients had emergency stenting performed for aortic transection or rupture. 30 days of survival post-procedure was recorded and complete. There were no major vascular complications. Deployment accuracy was 100%, and the technical success rate was 94.7% (18/19) with 1 patient having a type 2 endoleak on follow-up imaging. No neurological complications were noted. The mean operative time was 95 +/- 73.6 mins and the mean fluoroscopy time was 16.2 +/- 10.8 mins. Mean hospital stay for elective zone 2, 3 and 4 stenting was 5.3 +/- 3.8 days, and only 1 patient post zone 1 TEVAR required a brief (0.5 days) ICU stay. All procedures were performed via the percutaneous transfemoral route with 100% success in percutaneous closure. Conclusion This first reported Asian case series demonstrated versatility, safety, and efficacy of the Valiant NavionTM stent in Asian patients with different aortic pathologies

Dmitry Evseev

and 9 more

Background Langerhans cell histiocytosis (LCH) involves abnormal proliferation of Langerhans cells (LC), which is typically driven by the BRAF V600E mutation. High-risk LCH has a poor prognosis. Procedure Fifteen children (5 girls, 10 boys) with BRAF V600E+ LCH received vemurafenib (initial dose median 40 mg/kg/day, range: 11–51.6 mg/kg/day) between March 2016 and February 2020. All patients had previous received LCH-directed chemotherapy. The median age at LCH onset was 2 months (range: 1–28 months) and the median age at the start of vemurafenib treatment was 22 months (range: 13–62 months). The median disease activity score (DAS) at the start of vemurafenib treatment was 12 points (range: 2–22 points). Results The median duration of vemurafenib therapy was 29 months (range: 2.4–45 months). All patients responded to treatment, with median DAS values of 4 points (range: 0–14 points) at week 4 and 1 point (range: 0–3 points) at week 26. Toxicities included skin/hair changes (93%) and non-significant QT prolongation (73%). Two patients died, including 1 patient who experienced hepatic failure after NSAID overdose and 1 patient who developed neutropenic sepsis. Electively stopping vemurafenib treatment resulted in relapse in 5 patients, and complete cessation was only possible for 1 patient. Digital droplet PCR for BRAF V600E using cell-free circulating DNA revealed that 7 patients had mutation statuses that fluctuated over time. Conclusion Our study confirms that vemurafenib treatment is safe and effective for young children with BRAF V600E+ multisystem LCH. However, treatment using vemurafenib does not completely eliminate the disease.
Seed recruitment is a major driver of mangrove restoration globally. It is hypothesized that soil condition and channel hydrology can accelerate seedling recruitment and regeneration after a major disturbance. Species abundance, diversity indices, microbial and chemical concentrations in sand-filled mangrove forest was studied. Eight plots (area = 3902.16 m2) were established with ten transects in each plot in a random block design to investigate the effect of soil conditions on seedling growth. A total of 1, 886 seedlings were physically counted. Seedling abundance was significantly different between red (Rizophora racemosa), white (Laguncularia racemosa) and black (Avicennia germinans) mangroves and nypa palm (nypa fruticans). The most dominant species was black mangroves and the least dominant species was nypa palm. Muddy soils had the most abundant species while sandy soils had the least abundant species. Furthermore, semi-muddy soils had the highest species diversity (H = 0.948) whereas muddy soils had the least species diversity (H = 0.022). The soil metal concentration has no correlation with seed abundance and occur in the order Iron>Nitrate>Copper>Cadmium. Soil with high species diversity had high soil microbial population; however, seedling abundance was correlated with soil nutrients and not heavy metals. Small seeds are easily recruited while good soil condition plus existing hydrological connection facilitated natural seedling regeneration in the disturbed mangrove forest.

Rina Sha

and 3 more

Background: Although epicardial adipose tissue (EAT) has been proved be associated with atrial fibrillation (AF) and post-ablation AF recurrence, the relationship between EAT and AF after cardiac surgery (AFACS) is not evident, yet. Objective: In the study, we aim to perform a systematic review and meta-analysis to assess the association between EAT and AFACS and whether it is independent of the measurement methods. Methods: Systematic reach was implemented until May, 30, 2020, which “atrial fibrillation” and “epicardial adipose tissue” were as the main items in electronic databases. Analysis was stratified by EAT measurement methods into three pooled meta-analyses on 1) total EAT volume, 2) left atrium (LA)-EAT volume and 3) EAT thickness between two groups with and without AFACS, estimating standardized mean difference (SMD) with a random effect model. Results: Eight articles with ten studies (546 patients) were included. Accordingly, the results of meta-analysis showed that EAT was higher in AFACS subjects, regardless of the methods of EAT measurement.[ total EAT volume: SMD = 0.56 ml; 95% confidence interval (CI) = 0.56-1.10ml, I2 = 0.90, P=0.04; EAT thickness: SMD = 0.85mm; 95% CI = 0.04-1.65mm, I2 = 0.90, P=0.04; LA-EAT volume: SMD = 0.57ml, 95% CI = 0.23-0.92ml, I2 = 0.00, P=0.001.] And there was no evidence of publication bias. Conclusion: EAT may be a potential marker and therapeutic target for AFACS. However, larger scale studies are still required, and evaluation is needed to for further estimation.

Browse more recent preprints

Recently published in scholarly journals

Oktay Ucer

and 3 more

The sinoatrial node in medication-resistant inappropriate sinus tachycardia: to modify or to ablate?Khalil El Gharib1*1Hôtel-Dieu de France, Beirut, Lebanon*Author for correspondence: khalil.gharib@outlook.comKEYWORDS: IST, sinus node modification, sinus node ablation, radiofrequency ablation, surgical ablationNo conflict of interest to discloseFunding: noneInappropriate sinus tachycardia (IST) is defined as a resting heart rate >100 beats per minute (with a mean heart rate >90 beats per minute over 24 hours) associated with highly symptomatic palpitations(1). The syndrome is associated neither with structural heart disease nor with any secondary cause of sinus tachycardia(2) and evidence suggests that enhanced intrinsic automaticity of the sinoatrial node, which can be due to anti-β-adrenergic antibodies, is behind its genesis(3). However, it is benign in terms of clinical outcomes and echocardiographic evidence of ventricular dysfunction(4), being rarely associated with tachycardia-induced cardiomyopathy(3).Patients with IST are essentially treated with ß-blockers to alleviate their symptoms(5). Ivabradine, a drug that inhibits funny calcium channels, particularly abundant in the SA node, showed modest benefit, receiving class IIa recommen­dation in the treatment of IST(4). But, the duration of medical therapy might be indefinite, and, a considerable number of patients would respond inadequately, or have no response, even after prolonged therapy(5). Historically, such patients would have subtotal right atrial excision, atrioventricular junctional ablation with permanent pacemaker implantation, or chemical occlusion of the sinus node artery(6). These options are considered today unacceptable in this setting, and other therapeutic approaches should be unveiled when resistance to medical treatment appears.Electrophysiological study was initially purely diagnostic, but recent advances in technology have allowed us to intervene(7); patients with ventricular and supraventricular tachyarrhythmias are successfully treated with percutaneous catheter procedures. Of these, SA node ablation/ modification has been proposed as alternative approaches in IST that is not responding to medical treatment; trials reported auspicious results, highlighted here.Electrophysiologic mapping to the site of the earliest endocardial activation during either spontaneous sinus tachycardia or isoproterenol-induced sinus tachycardia has rendered these procedures feasible(8). Additionally, combination with intracardiac echocardiography permitted a more accurate electrophysiologic and anatomic localization of the sinoatrial node(9).Sinus node modification is not a focal ablation, but requires complete abolition of the cranial portion of the SA node complex, the one that exhibits the most of the autonomic activity(9). It is defined as successful when the heart rate decreases by 30 beats per minute (bpm) during isoproterenol infusion(8). Short-term success was also defined by other investigators when there was a reduction of the baseline sinus rate to less than 90 bpm and the sinus rate during isoproterenol infusion by more than 20% or by 25%(8). The acute success rate for modification has been varying between 76 and 100 % across trials, while long-term clinical outcomes are modest at best, with reported freedom from IST ranging from 23 to 85%(10).Complications specific to SA node modification include superior vena cava (SVC) syndrome, diaphragmatic paralysis, and sinus node dysfunction(10). And while modification with conventional methods has its setbacks, modification using laser energy can be considered in the setting of IST. This modality creates clear-cut homogenous transmural lesions of the myocardium that comprises the scattered “functional” SA node(11). The burnt myocardium will then heal into a dense fibrous scar, decreasing potential amplitudes. And when adapting laser energy settings to the thickness of the myocardial wall, collateral dam­ages such as esophageal fistulae, lung burns, and phrenic nerve palsy will be avoided(11); thus, this technique may prove itself as a new intriguing alternative for the safe and effective treatment of IST.SA node modification is apt in achieving acute reductions in postprocedural heart rate. However, and as aforementioned, success rates are suboptimal in terms of symptomatic control with a significant recurrence rate(12). Catheter ablation aiming at either total exclusion and obliteration of the SA node has been described and performed, success being defined as a slowing of >50% from the baseline rate of tachycardia along with a junctional escape rhythm(12). With radiofrequency (RF) applications, the earliest local atrial activation time would shift from a cranial location to a more caudal one, usually at the mid-lateral right atrium(5). Reviews have reported that acute success rates were consistently to be as high as 88.9%, with an overall frequency of recurrence of 19.6%, the latter occurring within a wide range of post-ablation intervals, anywhere from a few weeks to several months after the procedure(12). Additionally, Takemoto and colleagues documented a significant drop in B-type natriuretic peptide levels, 6 to 12 months after ablation, suggesting fewer stretching shears on cardiac muscle.Two types of response of the sinus tachycardia to RFA were observed across studies, whether a step-wise reduction in sinus rate accompanying migration of the site of earliest atrial activation in a cranial-caudal direction along the lateral right atrial wall, or an abrupt drop in heart rate in response to RFA at a focal site of earliest atrial activation(13).However, RFA of inappropriate sinus tachycardia requires a large number of applications of radiofrequency energy and is, as in SA node modification, associated with a high recurrence rate(13). Complete remission is achieved only in approximately 50% of patients in some studies(14); longer history of IST and those reporting near syncope/syncope having a higher probability of recurrence(15).While other studies have shown that RF ablation of the SA node can achieve even longer-term reductions in the sinus rate and relief of symptoms in two-thirds of patients with drug-refractory, inappropriate sinus tachycardia(13), aiming specific sites related to the SA node should be elaborated, for better and optimal outcomes Killu and colleagues created a lesion in the arcuate ridge resulting in complete abolition of the tachycardia, since arrhythmias arising in this region may exhibit both electrocardiographic and clinical similarities to IST(16). This has led to consider ablation of the arcuate ridge as a treatment of refractory IST, necessitating larger trials to confirm its potential role.Phrenic nerve injury is a severe and dreaded complication of SN ablation(12). Pericarditis, right diaphragmatic paralysis, and SVC syndrome are other undesirable side effects of the procedures, variously reported in studies. but a common complication was observed in them all, atrial tachyarrhythmias(12). It has been hypothesized that myocardial pathology, such as inflammation and fibrosis, considered iatrogenic due to the ablation procedures, may be promoting arrhythmias both in the region of the SA node, as well as in remote locations(12). Through multivariable analysis, higher resting heart rates post-ablation and smaller cranial-to-caudal shifts have been defined as predictors of atrial arrhythmias(15). In conclusion, catheter ablation could be considered an effective treatment for highly symptomatic, drug-refractory patients, even for those who did not respond to SA node modification(5).The sinus node is located close to the epicardial surface and catheter-based ablations do not always make full-thickness lesions across the atrial muscle, leading to failure of the ablation(17), besides the numerous trabeculae and the widely variable anatomy.Surgical ablation is not a first-line or routine management strategy for IST, but it has been proposed when IST resists or recurs after SN modification/ endocardial ablation(17). Effectively, in several studies, epicardial lesions, through a single small incision in one of the intercostal spaces, successfully slowed heart rate and shifted activation to a more caudal location, and surprisingly, subsequent endocardial lesions led to an even greater drop in heart rate and more caudal site of earliest activation(18). These outcomes were again replicated when using minimally invasive thoracoscopic ablation of the epicardial site of the SA node, concluding of the promising efficacy and the safety of this approach, since it preserves the phrenic nerve(17), although continued follow-up after surgery is required.Medication-resistant IST remains a medical challenge for physicians and cardiologists; and in the era of great advances in interventional cardiology, its treatment remains debatable. Sinus node modification/ ablation is not recommended as first-line therapy in IST, this procedure should be considered only in drug-refractory patients who have severe symptoms(13). Although the number of patients in the available studies is generally small, both procedures have documented an encouraging success rate in the short-term, while being less impressive in the long-term. It has been hypothesized that this discrepancy is due to the relatively large potential area of atrial pacemaker cells(18); modification or ablation may fail to ablate or isolate all the pathways that comprise the functional SA node because they often target the anatomic part and the area of earliest atrial activation(19). Others have explained that the long-term slowing in rhythm fails because these procedures inconsistently produce transmural lesions in the right atrium. Surgical treatment of IST has proposed a solution to the latter conflict when isolating the SA node with a wide cuff of surrounding atrial muscle(19). And with the advent of bipolar RF clamps and minimally invasive cardiac surgical techniques with thoracoscopic guidance, this approach appears more appealing than before, especially when combined with endocardial ablation(19). But again, current data specifies employing these techniques in highly selected cases.

Jerome FERRARA

and 10 more

Background: There is insufficient evidence regarding the comparison of Rapid Deployment aortic valve replacement(RDAVR) to TAVR in intermediate-risk patients with severe symptomatic aortic stenosis(AS) Aims: We compare the 2-years outcomes between RDAVR with INTUITY and TAVR with SAPIEN 3 in intermediate-risk patients with AS. Methods: Inclusion criteria: severe AS implanted with RDAVR or TAVR; EUROSCORE II ≥ 4% and clinical evaluation by Heart Team. Regression adjustment for the propensity score was used to compare RDAVR with TAVR(1:1). Primary endpoint: composite criterion of death, disabling stroke or rehospitalization. Secondary endpoints: occurrence of major bleeding post-operative complications, paravalvular regurgitation (PVR)≥2 and patient-prosthesis mismatch(PPM) at 1 month and pacemaker implantation at 2 years. Results: A total of 152 patients were included from 2012 to 2018: 48 in the RDAVR group and 104 in the TAVR group. Mean age was 82.7±6, 51.3% were female, mean Euroscore II was 6.03±1.6% and mean baseline LVEF was 56±13%,mean indexed iEOA was 0.41±0.1cm/m2, mean gradient was 51.7±14.7mmHg. Patients with RDAVR were younger(79.5±6vs82.6±6,p=0.01), at higher risk (EUROSCORE2 6,61±1,8%vs5,63±1,5%, p=0.005), combined surgery was performed in 28 patients(58.3%). Twenty-two patients(45.99%) met the primary outcome in the RDAVR group and 32 patients(66.67%) in the TAVR group. By 1:1propensity score matching analysis, there was a significant difference between both groups in favor of RDAVR(HR=0.58[95%CI:0.34;1.00],p=0.04). No difference were observed in PPM occurrence(0.83;[0.35-1.94];p=0.67),major bleeding events(1.33;[0.47-3.93];p=0.59),PVR≥2(0.33[0-6.28],p=0.46), and pacemaker implantation (0.84[0.25-2.84],p=0.77).Conclusion: RDAVR is associated with better 2-years outcomes than TAVR in intermediate-risk patients with severe symptomatic AS.

Francesca Mori

and 10 more

Marco Moscarelli

and 9 more

Objective: Cardiac tumors are rare conditions. The vast majority of them are benign yet they may lead to serious complications. Complete surgical resection is the gold standard treatment and should be performed as soon as the diagnosis is made. Median sternotomy (MS) is the standard approach and provides excellent early outcomes and durable results at follow-up. However, minimally invasive (MI) is gaining popularity and its role in the treatment of cardiac tumors needs further clarification. Methods: A systematic literature review identified 12 candidate studies; of these, 11 met the meta-analysis criteria. We analyzed outcomes of 653 subjects (294 MI and 359 MS) with random effects modeling. Each study was assessed for heterogeneity. The primary endpoints were mortality at follow-up and tumor relapse. Secondary endpoints included relevant intra- and post-operative outcomes; tumor size was also considered. Results: There were no significant between-group differences in terms of late mortality (incidence rate ratio (IRR): MI vs. MS, 0.98 [95% CI: 0.25¬–3.82], p = 0.98). Few relapses and redo surgery were observed in both groups (IRR: 1.13[0.26-4.88], p=0.87);( IRR: 1.92 [95% CI: 0.39-9.53], p=0.42); MI was associated to prolonged operation time yet with no effects on clinical outcomes. Tumor size did not significantly differ between groups. Conclusions: Both MI and MS are associated with excellent early and late outcomes with acceptable survival rate and low incidence of recurrences. This study confirms that cardiac tumor may be approached safely and radically with a MI approach.

Browse more published preprints

How it works

Upload or create your research work
You can upload Word, PDF, LaTeX as well as data, code, Jupyter Notebooks, videos, and figures. Or start a document from scratch.
Disseminate your research rapidly
Post your work as a preprint. A Digital Object Identifier (DOI) makes your research citeable and discoverable immediately.
Get published in a refereed journal
Track the status of your paper as it goes through peer review. When published, it automatically links to the publisher version.
Learn More
Featured collections
Explore More Collections

Other benefits of Authorea

Multidisciplinary

A repository for any field of research, from Anthropology to Zoology

Comments

Discuss your preprints with your collaborators and the scientific community

Interactive Figures

Not just PDFs. You can publish d3.js and Plot.ly graphs, data, code, Jupyter notebooks

Featured templates
Featured and interactive
Journals with direct submission
Explore All Templates