Photo-Responsive Ascorbic Acid-Modified Ag2S-ZnS Heteronanostructure Dropping pH to Trigger Synergistic Antibacterial and Bohr Effects for Accelerating Infected Wound Healing

Nonantibiotic approaches must be developed to kill pathogenic bacteria and ensure that clinicians have a means to treat wounds that are infected by multidrug-resistant bacteria. This study prepared matchstick-like Ag2S-ZnS heteronanostructures (HNSs). Their hydrophobic surfactants were then replaced with hydrophilic poly(ethylene glycol) (PEG) and thioglycolic acid (TGA) through the ligand exchange method, and this was followed by ascorbic acid (AA) conjugation with TGA through esterification, yielding well-dispersed PEGylated Ag2S-ZnS@TGA-AA HNSs. The ZnS component of the HNSs has innate semiconductivity, enabling the generation of electron-hole pairs upon irradiation with a light of wavelength 320 nm. These separate charges can react with oxygen and water around the HNSs to produce reactive oxygen species. Moreover, some holes can oxidize the surface-grafted AA to produce protons, decreasing the local pH and resulting in the corrosion of Ag2S, which releases silver ions. In evaluation tests, the PEGylated Ag2S-ZnS@TGA-AA had synergistic antibacterial ability and inhibited Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus (MRSA). Additionally, MRSA-infected wounds treated with a single dose of PEGylated Ag2S-ZnS@TGA-AA HNSs under light exposure healed significantly more quickly than those not treated, a result attributable to the HNSs' excellent antibacterial and Bohr effects.

Predictors and Outcomes of Acute Brain Injury in Patients on Venoarterial Extracorporeal Membrane Oxygenation after Cardiopulmonary Resuscitation

Background

Venoarterial (V-A) extracorporeal membrane oxygenation (ECMO) after cardiac arrest often predisposes patients to acute brain injury (ABI), which affects survival and neurological performance. The investigation of the predictors of ABI will be beneficial for further management.

Objectives

To explore the predictors and outcomes of ABI and intracerebral hemorrhage (ICH) in patients experiencing cardiac arrest and cardiopulmonary resuscitation (CPR) with V-A ECMO support.

Methods

We retrospectively analyzed 150 patients who successfully weaned from V-A ECMO support after pre-ECMO CPR at our institution from January 2009 to December 2021. Short-term and long-term outcomes were evaluated. Characteristics before and during ECMO were analyzed for determining the predictors of ABI and ICH.

Results

Of the 150 patients, 66 (44.0%) had ABI. ABI was associated with higher in-hospital mortality (62.1% vs. 21.4%, p < 0.0001) and poorer long-term survival after discharge (p = 0.002). Patients who survived to discharge with ABI had significantly more severe neurological deficits at discharge (84.0% vs. 42.4%, p < 0.0001) and improved little at one year after discharge (33.3% vs. 11.4%, p = 0.027). We found that CPR duration [odds ratio (OR) = 1.04, p = 0.003] was the independent risk factor for ABI, whereas lower platelet counts was the independent risk factor for ICH (OR = 0.96, p = 0.019).

Conclusions

After CPR, development of ABI during V-A ECMO support impacted survival and further neurological outcome. Longer CPR duration before ECMO set up significantly increases the occurrence of ABI. Besides, severe thrombocytopenia during ECMO support increases the possibility of ICH.

Aortic root remodeling after surgical repair of acute type A aortic dissection using different anastomosis techniques

Background

After surgical repair of acute type A aortic dissection (aTAAD), remodeling of the residual aortic segments is the key outcome parameter associated with late reoperation or aorta-related adverse events. In this study, we analyzed the surgical outcomes of aTAAD using either a telescopic or continuous anastomosis technique, focusing on their impact on aortic root remodeling during the longitudinal follow-up.

Methods

Between 2012 and 2018, 112 surgical repairs of aTAAD with ascending aorta replacement and without aortic arch or aortic root replacement were performed. The medical records were reviewed retrospectively, and early and late outcomes were compared between the telescopic and continuous anastomosis techniques. The generalized estimating equation method was used to analyze the effects of different anastomosis techniques on serial aortic root remodeling.

Results

The telescopic anastomosis technique was used in 46 cases (41.1%), and the conventional continuous anastomosis technique was used in 66 cases (58.9%). There were no differences in in-hospital mortality or the incidence of major complications between the groups. The telescopic anastomosis group demonstrated stable postoperative regression of the aortic root diameter during follow-up. In contrast, the continuous anastomosis group showed a progressive dilatation of the aortic root. There was a trend toward better aortic root adverse event-free survival rates in the telescopic anastomosis group (P = .081).

Conclusions

The telescopic anastomosis technique is a safe alternative to the continuous anastomosis technique in the surgical repair of aTAAD, with comparable early results. In addition, telescopic anastomosis was associated with beneficial aortic root remodeling in the medium term compared with continuous anastomosis.

Surgical ligation, not transcatheter closure, associated with a higher severity of bronchopulmonary dysplasia in extremely preterm infant intervened for patent ductus arteriosus

OBJECTIVE

Patent ductus arteriosus (PDA) is a common complication among premature infants, which may be responsible for prematurity-related complications such as bronchopulmonary dysplasia (BPD). It is unclear whether different interventional methods contribute to the severity of BPD, given the original National Institute of Child Health and Human Development (NICHD) 2001 definition. To date, surgical ligation and the transcatheter approach have been equally successful in premature infants with hemodynamically significant PDA after medical treatment failure. Immediate improvement in the respiratory condition has been reported after transcatheter closure. However, the short-term pulmonary outcome has not been clarified yet.

METHODS

This retrospective study investigated infants born with a body weight <1000 g and who underwent either surgical ligation or transcatheter closure of PDA in a single tertiary institution. The infants were divided into groups according to the type of procedure (surgical ligation or transcatheter occlusion). The primary outcome was the severity of BPD at discharge or at a postmenstrual age of 36 weeks. The outcome was analyzed with logistic regression.

RESULTS

Forty-four patients met the inclusion criteria, of whom 14 underwent transcatheter occlusion and 30 underwent surgical ligation. The overall birth body weights and gestational age ranges were not different. The univariate model revealed an association between the procedure type and BPD severity. After adjusting for confounders, the multivariate model confirmed associations between BPD severity and procedure type and severe respiratory distress syndrome requiring surfactant.

CONCLUSION

Compared with the transcatheter approach, surgery for PDA in extremely preterm infants is associated with severe BPD at discharge. Further large-scale studies are needed to determine the exact mechanism.

Editor's Choice - Infective Native Aortic Aneurysms: A Delphi Consensus Document on Terminology, Definition, Classification, Diagnosis, and Reporting Standards

OBJECTIVE

There is no consensus regarding the terminology, definition, classification, diagnostic criteria, and algorithm, or reporting standards for the disease of infective native aortic aneurysm (INAA), previously known as mycotic aneurysm. The aim of this study was to establish this by performing a consensus study.

METHODS

The Delphi methodology was used. Thirty-seven international experts were invited via mail to participate. Four two week Delphi rounds were performed, using an online questionnaire, initially with 22 statements and nine reporting items. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements revised, and results presented in iterative rounds. Consensus was defined as ≥ 75% of the panel selecting "strongly agree" or "agree" on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha coefficient > .80.

RESULTS

All 38 panellists completed all four rounds, resulting in 100% participation and agreement that this study was necessary, and the term INAA was agreed to be optimal. Three more statements were added based on the results and comments of the panel, resulting in a final 25 statements and nine reporting items. All 25 statements reached an agreement of ≥ 87%, and all nine reporting items reached an agreement of 100%. The Cronbach's alpha increased for each consecutive round (round 1 = .84, round 2 = .87, round 3 = .90, and round 4 = .92). Thus, consensus was reached for all statements and reporting items.

CONCLUSION

This Delphi study established the first consensus document on INAA regarding terminology, definition, classification, diagnostic criteria, and algorithm, as well as reporting standards. The results of this study create essential conditions for scientific research on this disease. The presented consensus will need future amendments in accordance with newly acquired knowledge.

Custom-designed sensors embedded 3D-printed wearable device for improving the hemodialysis-related vascular dysfunction detection

BACKGROUND

The increasing prevalence of end-stage renal disease (ESRD) imposes a substantial economic burden on public health-care systems. Hemodialysis (HD) is a pivotal treatment modality for patients with ESRD. However, prolonged use of HD vessels may result in stenosis, thrombosis, and occlusion due to repeated daily punctures. Thus, early detection and prevention of the dysfunction of dialysis routes are crucial.

OBJECTIVE

In this study, we designed a wearable device for the early and accurate detection of arteriovenous access (AVA) stenosis in HD patients.

METHODS

A personalized three-dimensional (3D) printed wearable device was designed by combining the phonoangiography (PAG) and photoplethysmography (PPG) techniques. The capability of this device to monitor AVA dysfunction before and after percutaneous transluminal angioplasty (PTA) was evaluated.

RESULTS

After PTA, the amplitudes of both PAG and PPG signals increased in patients with arteriovenous fistulas and those with arteriovenous grafts; this might be due to increased blood flow.

CONCLUSION

Our designed multi-sensor wearable medical device using PAG, PPG, and 3D printing appears suitable for early and accurate detection of AVA stenosis in HD patients.

Potential of Autologous Progenitor Cells and Decellularized Porcine Artery Matrix in Construction of Tissue-engineered Vascular Grafts

To develop a tissue-engineered vascular graft, we used pericardial effusion-derived progenitor cells (PEPCs) collected from drained fluid after open-heart surgery in children with congenital heart diseases to repopulate a decellularized porcine pulmonary artery. The PEPCs were compared with human fibroblasts (HS68) and human umbilical vein endothelial cells (HUVECs) in cell growth and migration. They were cultured with the matrices via an inner approach (intima), lateral approach (media), and outer approach (adventitia). PEPCs grew and migrated better than the other two cells 14 days after seeding in the decellularized vessel. In immunofluorescence assays, PEPCs expressed CD90 and CD105 indicating a vascular differentiation. PEPCs grew in a decellularized porcine pulmonary artery matrix may have the potential for producing tissue-engineered vascular grafts.

Outcomes of acute type A aortic dissection operations performed by early-career cardiovascular surgeons

Objective

Surgical outcomes of acute type A aortic dissection have been recognized to be associated with the surgical volume of individual hospitals and surgeons. In this study, we aimed to investigate the results and learning curves of acute type A aortic dissection operations performed by early-career cardiovascular surgeons.

Methods

A total of 248 surgical repairs of acute type A aortic dissections were conducted at a tertiary medical center between 2010 and 2018. By using the cumulative sum test, cardiovascular surgeons in their early career were identified, and their performances were assessed. The outcomes of patients who were operated by early-career cardiovascular surgeons were compared with those by experienced or senior surgeons.

Results

During the study period, 202 (81.5%) of the 248 acute type A aortic dissection operations were performed primarily by the 4 newly appointed attending cardiovascular surgeons. In cumulative sum curves, all surgeons exhibited a steady performance throughout the study period. On the basis of our institutional result of acute type A aortic dissection operation, early career was defined as performing fewer than 32 acute type A aortic dissection operations. The 30-day mortality rates of acute type A aortic dissection operations performed by early-career surgeons were equivalent to those performed by experienced/senior surgeons (10.9% vs 12.5%, P = .844). There was also no difference in mid-term overall survival and aortic event-free survival between the 2 groups (P = .638 and P = .574, respectively).

Conclusions

In a center with a well-established program, cardiovascular surgeons could accomplish surgical repair of acute type A aortic dissection with adequate early- and mid-term results from the initiation of their careers.

Ascending aorta replacement vs. total aortic arch replacement in the treatment of acute type A dissection: a meta-analysis

OBJECTIVE

Acute type A aortic dissection (ATAAD) is a severe, rapidly progressing disease which typically requires patients to undergo emergency surgical intervention. Despite advancements in surgical procedures, still, ATAAD remains a surgical emergency associated with high mortality. The aim of this systematic review and meta-analysis was to compare whether either ascending aorta replacement (AR) or total aortic arch replacement (TR) leads to improved short- and long-term clinical outcomes.

MATERIALS AND METHODS

A search of PubMed, Embase, Science Direct, Web of Science, SciELO, BIOSIS, and China National Knowledge Infrastructure (CNKI) databases were supplemented by searching through bibliographies of key articles. Thereafter, data on early and late prognostic factors were extracted. A systematic review and meta-analysis of 15 studies were performed to compare whether either AR or TR leads to a reduction in the risk of in-hospital and short-term mortality, postoperative complications, re-operation rate, and long-term mortality.

RESULTS

A total of 15 cohort studies (n = 2822 patients with ATAAD; AR with HA, partial arch = 1911, TR = 911) were deemed eligible and included in the meta-analysis. Compared with TR, AR led to a significantly lower risk of in-hospital mortality (RR = 0.77; 95% CI: 0.61-0.96), shorter cardiopulmonary bypass time (CPB, mean difference = -53.09; 95% CI: -56.68--49.50), circulatory arrest time (CA, mean difference = -8.09; 95% CI: -9.04-7.15), and antegrade cerebral perfusion (ACP, mean difference = -28.62; 95% CI: -30.23--27.00). Differences in the incidence rates of neurological dysfunctions and renal dialysis were not significant. The pooled rate of aortic re-operation was lower in TR group (AR 7.6% vs. TR 5.3%), albeit not significantly (risk ratio = 1.39; 95% CI: 0.94-2.07; p = 0.10).

CONCLUSIONS

These findings demonstrate that AR is associated with a lower early mortality rate and shorter operative times overall. Nevertheless, the incidence of postoperative complications in patients undergoing AR is comparable to that of patients undergoing TR. Further prospective follow-up data needs to be collected and analyzed to discern whether there are statistically significant differences in the risks of re-operation and long-term mortality between AR and TR procedures.

Diastolic and systolic right ventricular diameters for predicting pulmonary hypertension in children with congenital heart disease

Prospective electrocardiography (ECG)-gated cardiac computed tomography angiography (CTA) is widely used for pediatric patients with congenital heart disease (CHD) due to the lower radiation dose compared with the ECG-gated technique. However, functional parameters acquired using ECG-gated cardiac CT to predict pulmonary hypertension (PH) in children with CHD have not yet been reported. This study aimed to investigate the potential of diastolic and systolic right ventricular diameters (RVD) on prospective ECG-gated cardiac CTA to predict PH in children with CHD. A total of 44 children with CHD were divided into two groups: CHD with PH (n = 22) and CHD without PH (n = 22). The association between ECG-gated CTA parameters and PH was evaluated by logistic regression. The receiver operating characteristic curve (ROC) was used to find the best cut-off point for the parameters measured by Youden's index. Patients with higher RVD-BSA [aOR (95% CI) diastolic: 2.76 (1.23-6.23); systolic: 6.15 (1.72-22.06)] had higher risk of PH after adjusting for age and patent ductus arteriosus. The area under the curve (AUC) of D-RVD-BSA was 0.907 and the AUC of S-RVD-BSA was 0.917. Logistic regression showed that patients with D-RVD-BSA over 6.86 or S-RVD-BSA over 5.87 had significantly higher risk of PH after adjustments (aOR = 23.52, 95% CI = 2.89-191.03; aOR = 31.14, 95% CI = 2.75-352.85). In conclusion, in children with CHD, measurements of diastolic or systolic BSA-modified RVDs on prospective ECG-gated CTA are non-invasive markers of PH. BSA-modified D-RVD of 6.86 or BSA-modified S-RVD of 5.87 may be used to identify PH in children with CHD.

Post-Coronary Artery Bypass Medications in Dialysis Patients: Do We Need to Change Strategies?

BACKGROUND

Coronary artery bypass grafting (CABG) is frequently performed in patients with end-stage renal disease (ESRD) together with severe coronary artery disease, after which, patients with ESRD have higher surgical risk and poorer long-term outcomes. We report our experience in patients with ESRD who survived in CABG and identify predictors of long-term outcomes.

METHODS

We retrospectively investigated 93 consecutive patients with ESRD who survived to discharge after isolated CABG between January 2005 and December 2016 at our institution. Long-term outcomes, including all-cause mortality after discharge, readmission due to major adverse cardiac events, and reintervention, were evaluated. Predictors affecting long-term outcomes were also analyzed.

RESULTS

The rates of freedom from all-cause mortality after discharge in 1, 3, 5, and 10 years were 92.1, 81.3, 71.9, and 34.9%, respectively. The rates of freedom from readmission due to major adverse cardiac events in 1, 3, 5, and 10 years were 90.7, 79.1, 69.9, and 55.6%, respectively. The rates of freedom from reintervention in 1, 3, 5, and 10 years were 95.3, 86.5, 79.0, and 66.6%, respectively. Postoperative β-blocker and statin use significantly improved overall long-term survival (β-blocker, p = 0.013; statin, p = 0.009). After case-control matching, patients who received statins showed better long-term survival than those without statins. The comparison of long-term survival between patients with and without β-blockers showed no significant difference after matching.

CONCLUSIONS

After CABG, dialysis patients who survived to discharge had acceptable long-term overall survival. Post-CABG statin use in dialysis patients is a predictor of better long-term survival.

Progenitor Cells Derived from Drain Waste Product of Open-Heart Surgery in Children

Human cardiac progenitor cells isolated from the same host may have advantages over other sources of stem cells. The aim of this study is to establish a new source of human progenitor cells collected from a waste product, pericardiac effusion fluid, after open-heart surgery in children with congenital heart diseases. The fluid was collected every 24 h for 2 days after surgery in 37 children. Mononuclear cells were isolated and expanded in vitro. These pericardial effusion-derived progenitor cells (PEPCs) exhibiting cardiogenic lineage markers, were highly proliferative and enhanced angiogenesis in vitro. Three weeks after stem cell transplantation into the ischemic heart in mice, cardiac ejection fraction was improved significantly without detectable progenitor cells. Gene expression profiles of the repaired hearts revealed activation of several known repair mechanisms including paracrine effects, cell migration, and angiogenesis. These progenitor cells may have the potential for heart regeneration.

Application of two-dimensional fractional-order convolution and bounding box pixel analysis for rapid screening of pleural effusion

Pleural effusion is a pathologic symptom in which there is accumulation of body fluids around the lungs. A chest radiograph is a rapid examination technique and does not require complex setup for making a preliminary diagnosis of lung and heart diseases. In radiographic visualization, the symptom patterns appear as light or dark areas in the lung cavity. Computer-aided diagnosis is an automatic manner that can rapidly highlight the object region by preanalyzing medical images. It can improve the problems of manual inspection and allow diagnosis in remote medical facilities. Based on the ratios of lung anatomy, the automatic screening manner based on pattern recognition can be viewed as pixel value detection in the bilateral lung cavities. In this study, a fractional-order convolution (FOC) process is used to enhance the original image for an accurate extrapolation of the desired object in an image. The specific object image feature can be improved, and an accurate quantification of the pleural effusion region can be obtained using the suitable ranges of fractional-order parameters. Based on the boundaries of homogeneous regions, the pixel ratios of the lung anatomy between normal and abnormal conditions can be computed. The pleural effusion sizes and volumes can be rapidly estimated through the number of pixel changes. The experimental results reveal that the feature maps are similar and stable on image enhancement and segmentation with two fractional-order enhancement masks, as fractional-order v = 0.05 to 0.20 for mask 1# and v = 0.80 to 0.95 for mask 2#, respectively. The results also demonstrate the feasibility of the study on combining two-dimensional image FOC-process and bounding box pixel analysis to estimate the moderate and large effusion sizes from 500-2,000 mL.

In Vitro Hemodynamic Evaluation of Right Ventricle-Pulmonary Artery Continuity Reconstruction Through a Trileaflet Expanded Polytetrafluoroethylene Valved Conduit

Percutaneous pulmonary valve implantation is a technique to treat narrowed pulmonary valves or leaky pulmonary valves in congenital heart disease. This technique provides a promising strategy to reduce surgical risk. In clinical cases, due to stent size restrictions, commercial valve stents are sometimes unsuitable for children or certain patients. Hence, handmade pulmonary valved conduits prove useful because a customized size can be obtained for valve replacement. We propose a meta-learning-based intelligent model to train an estimator (including two sub-estimators) to determine optimal trileaflet parameters for customized trileaflet valve reconstruction. The purpose of this study was to investigate the hemodynamic and functional consequences of the novel design by employing a mock circulation system. We recorded the diastolic valve leakage and calculated the pulmonary regurgitation, regurgitation fraction, and ejection efficiency in a pulsatile setting. The prosthetic leaflet behavior was assessed using an endoscope camera and the pressure drops through valves were measured. All the in vitro parameters indicated that the expanded polytetrafluoroethylene (ePTFE) valved conduits were not inferior to commercial mechanical or tissue valve conduits and could decrease the regurgitation volume and increase the efficiency. Compatible early clinical outcomes were also identified between ePTFE valved conduits and other valved conduits used for right ventricular outflow tract reconstruction. The ePTFE valved conduits could be implanted in relatively small patients. An in vitro experimental study provided evidence that a handmade ePTFE valved conduit could be an attractive alternative to other commercialized valved conduits used for right ventricle-pulmonary artery continuity reconstruction.

Using cell-seeded electrospun patch for myocardial injury: in-vitro and in rat model

Electrospinning has been widely used to fabricate scaffolds and commonly used biodegradable polymers. Cellular cardiomyoplasty is a type of regenerative medicine that has potential use for treatment of myocardial infarction or terminal cardiac failure. The aims of this study are to use electrospinning to create cardiovascular patches and to assess their potential therapeutic use by transplantation into the hearts of rats. Tissue engineering scaffolds were generated by use of electrospinning, in which the fibers consist of nanoscale-to-microscale fibers whose diameters are comparable to those of essential components of the extracellular matrix. A polymer solution was pumped at a constant rate through a syringe with a small-diameter needle that is connected to a high-voltage source, so that an electric field is created between the needle and a metallic collecting plate. The final product is a mat composed of individual continuous nanofibers. Cell survival, cell characteristics, and growth factors of electrospun patches of different thicknesses using bone marrow and human cardiac stem cells were tested. The results demonstrated that the cells can survive in Poly-caprolactone (PCL) patches, even deep within these patches. The PCL patches are nontoxic and do not alter cell properties. Transplantation of these patches into the hearts of a rat model of myocardial infarction led to strong compliance and good survival.The use of PCL cellular patches is feasible method for cellular transplantation. Future studies should attempt to use orientated electrospun cellular patches to improve overall cell survival within deeper layers of these patches.

Substitution-rate based screening model to assess stenosis progression in experimental stenotic arteriovenous grafts

An arteriovenous graft (AVG) has a higher patency rate in stenosis progression at the venous anastomosis site, which causes coexisting inflow and outflow stenoses. This leads to increases in blood pressure, flow velocity, and flow resistance, resulting in hemodialysis (HD) vascular access dysfunction from early clots and thrombosis to the progression of coexisting stenoses. To prevent vascular access complications such as inflow or outflow stenoses, this study proposes a novel examination method in an experimental AVG system using a substitution-rate based screening model. In our practical measurements, we found that inflow and outflow channeled through a narrowed access indicated both pressure and resistance differences as the degree of stenosis (DOS) gradually increased. A substitution-rate matrix was conducted to replace bilateral pressure variations, while a transition probability matrix was calculated. Differences in transition probabilities were then used to distinguish between normal conditions and flow instabilities using the distance estimation method. The joint probability decayed from < 0.81 to 0.00 could be specified to identify the progression in stenosis levels from a DOS% = 50.0-95.0%. Average joint probabilities were found to be inversely related with the DOS using a non-linear regression (R>2 0.90). Hence, the joint probability could be specified as a critical threshold, < 0.81, to identify the severity stenosis level, DOS% ⩾ 70%, in the assessment of coexisting inflow and outflow stenoses. Experimental results suggest that the proposed model is superior to hemodynamic analysis and traditional intelligent method, and can be used for dysfunction screening during HD treatment.

Handmade trileaflet valve design and validation for patch-valved conduit reconstruction using generalized regression machine learning model

Pulmonary valve diseases include the different degrees of aortic stenosis or congenital defects in children or adults. Valve repair or replacement surgery is commonly performed to relieve valvular dysfunction and improve the significant flow regurgitation in the aortic valve and the pulmonary valve. However, commercial valve stents and valved conduits are sometimes not available for children or patients with special conditions. The handmade trileaflet valve design has been used with different range of diameters for patch-valved conduit reconstruction. Thus, we propose a multiple regression model, as a generalized regression neural network (GRNN), to determine the optimal trileaflet parameters, including the width, length, and upper lower curved structure. Through computed tomography pulmonary angiography, while the diameter of the main pulmonary artery is determined, a leaflet template can be rapidly sketched and made. Using an experimental pulmonary circulation loop system, the efficacy of the valved conduit can be validated using the regurgitation fraction method. In contrast to commercial valve stents, experimental results indicate that the handmade trileaflet valve can also improve severe pulmonary regurgitations.

Role of Endovascular Aortic Repair in the Treatment of Infected Aortic Aneurysms Complicated by Aortoenteric or Aortobronchial Fistulae

Background The aim of this study was to compare outcomes and identify factors related to increased mortality of open surgical and endovascular aortic repair (EVAR) of primary mycotic aortic aneurysms complicated by aortoenteric fistula (AEF) or aortobronchial fistula (ABF).

Methods Patients with primary mycotic aortic aneurysms complicated by an AEF or ABF treated by open surgery or endovascular repair between January 1993 and January 2014 were retrospectively reviewed. Outcomes were compared between the open surgery and endovascular groups, and a Cox's proportional hazard model was used to determine factors associated with mortality.

Results A total of 29 patients included 14 received open surgery and 15 received endovascular repair. Positive initial bacterial blood culture results included Salmonella spp., oxacillin-resistant Staphylococcus aureus, and Klebsiella pneumoniae. Mortality within 1 month of surgery was higher in the open surgery than in the endovascular group (43 vs. 7%, respectively, p = 0.035). Shock, additional surgery to repair gastrointestinal (GI) or airway pathology, and aneurysm rupture were associated with a higher risk of death. Compared with patients without resection surgery, the adjusted hazard ratio of death within 4 years in patients with resection for GI/bronchial disease was 0.25. Survival within 6 months was better in the endovascular group (p = 0.016).

Conclusion The results of this study showed that EVAR/thoracic EVAR (TEVAR) is feasible for the management of infected aortic aneurysms complicated by an AEF or ABF, and results in good short-term outcomes. However, EVAR/TEVAR did not benefit long-term survival compared with open surgery.

Predictable capability control scheme for oxygen-exchange blood flow regulation in an extracorporeal membrane oxygenation system

Extracorporeal membrane oxygenation system is used for rescue treatment strategies for temporary cardiopulmonary function support to facilitate adequately oxygenated blood to return into the systemic and pulmonary circulation systems. Therefore, a servo flow regulator is used to adjust the roller motor speed, while support blood flow can match the sweep gas flow (GF) in a membrane oxygenator. A generalised regression neural network is designed as an estimator to automatically estimate the desired roller pump speed and control parameters. Then, the proportional-integral-derivative controller with tuning control parameters showed good performance to achieve speed regulation and speed tracking in the desired operating point. Given the pressure of carbon dioxide, drainage blood flow, and cannula size, the proposed predictable capability control scheme can be validated to meet the intended uses in clinical applications.

The Addition of Epinephrine to Proxymetacaine or Oxybuprocaine Solution Increases the Depth and Duration of Cutaneous Analgesia in Rats

BACKGROUND

The aim of this experiment was to investigate the interaction between epinephrine and 2 local anesthetics (proxymetacaine or oxybuprocaine) using subcutaneous injections under the hairy skin, thereby simulating infiltration blocks.

METHODS

Using a rat model of cutaneous trunci muscle reflex in response to local skin pinpricks, the anesthetic properties of proxymetacaine and oxybuprocaine alone and in combination with epinephrine as an infiltrative anesthetic were tested. Isobolographic analysis was used for the analgesic interactions between adjuvant epinephrine and the local anesthetics. Lidocaine was used as a control group.

RESULTS

Oxybuprocaine, proxymetacaine, and lidocaine elicited a dose-dependent block to pinpricks. On the 50% effective dose (ED50) basis, their relative potencies were proxymetacaine [0.126 (0.113-0.141) μmol] greater than oxybuprocaine [0.208 (0.192-0.226) μmol] greater than lidocaine [6.331 (5.662-7.079) μmol] (P < 0.01 for each comparison). On an equipotent basis (ED25, ED50, and ED75), sensory block duration elicited by oxybuprocaine or proxymetacaine was greater than that elicited by lidocaine (P < 0.01). Coadministration of proxymetacaine, oxybuprocaine, or lidocaine with epinephrine produced a synergistic analgesic effect and prolonged the cutaneous analgesic effect. After adding epinephrine, oxybuprocaine was much faster, reaching its maximal blockade, than proxymetacaine or lidocaine (P < 0.01).

CONCLUSIONS

We concluded that proxymetacaine and oxybuprocaine were more potent and produced greater duration of nociceptive block than lidocaine. The use of epinephrine augmented the potency and prolonged the duration of proxymetacaine, oxybuprocaine, and lidocaine as an infiltrative anesthetic.

Apparatus for Comparison of Pullout Forces for Various Thoracic Stent Grafts at Varying Neck Angulations and Oversizes

BACKGROUND

The purpose of this study is to provide an apparatus for comparison of pullout forces for various thoracic stent grafts at varying neck angulations and oversizes.

METHODS

An in vitro platform capable of performing pullout tests was used on stent grafts in angulated silicone tubes designed for this study (0°, 45°, 90°, and 135° with a 32-mm inner diameter) in a temperature-controlled chamber (37 ± 2°C). Three commercial stent grafts with sizes commonly used in Taiwan (Valiant: 34, 36, 38, and 40 mm; Zenith TX2: 34, 36, 38, and 40 mm; and TAG: 34, 37, and 40 mm) were used, and each size was tested 8 times for each angulation condition.

RESULTS

The mean dislodgement forces (DFs) at 0° angulation within 10-20% oversize were approximately 22.7, 9.6, and 9.0 N for the Valiant, Zenith TX2, and TAG devices, respectively, whereas the mean DFs decreased by 46%, 38%, and 50% to 12.3, 5.9, and 4.5 N when the angulation reached 135°. Regression analysis shows that neck angulation was a significant factor for the Valiant and Zenith TX2 devices (P < 0.0001 and P < 0.0001, respectively) but not for the TAG device (P = 0.483). In addition, oversize and interactions between variables (angulation × oversize) exhibited significant effects on the DFs for all devices (P < 0.0001).

CONCLUSIONS

We successfully built up an apparatus for comparison of pullout forces for various thoracic stent grafts at varying neck angulations and oversizes. With the empirical comparative data of different brand stent grafts under various conditions shown and compared, our findings suggest that aortic neck angulation has a negative correlation with stent-graft fixation. To have better stent-graft fixation and seal in the aortic arch for thoracic endovascular aortic repair, a longer landing zone with cautiously selected oversize is a more suitable selection.

Detection of venous needle dislodgement during haemodialysis using fractional order shape index ratio and fuzzy colour relation analysis

Venous needle dislodgement (VND) is a life-threatening complication during haemodialysis (HD) treatment. When VND occurs, it only takes a few minutes for blood loss in an adult patient. According to the ANNA (American Nephrology Nurses' Association) VND survey reports, VND is a concerning issue for the nephrology nurses/staff and patients. To ensure HD care and an effective treatment environment, this Letter proposes a combination of fractional order shape index ratio (SIR) and fuzzy colour relation analysis (CRA) to detect VND. If the venous needle drops out, clinical examinations show that both heart pulses and pressure wave variations have a low correlation at the venous anatomic site. Therefore, fractional order SIR is used to quantify the differences in transverse vibration pressures (TVPs) between the normal condition and meter reading. Linear regression shows that the fractional order SIR has a high correlation with the TVP variation. Fuzzy CRA is designed in a simple and visual message manner to identify the risk levels. A worst-case study demonstrated that the proposed model can be used for VND detection in clinical applications.

A rule-based decision-making diagnosis system to evaluate arteriovenous shunt stenosis for hemodialysis treatment of patients using fuzzy petri nets

This paper proposes a rule-based decision-making diagnosis system to evaluate arteriovenous shunt (AVS) stenosis for long-term hemodialysis treatment of patients using fuzzy petri nets (FPNs). AVS stenoses are often associated with blood sounds, resulting from turbulent flow over the narrowed blood vessel. Phonoangiography provides a noninvasive technique to monitor the sounds of the AVS. Since the power spectra changes in frequency and amplitude with the degree of AVS stenosis, it is difficult to make a human-made decision to judge the degree using a combination of those variances. The Burg autoregressive (AR) method is used to estimate the frequency spectra of a phonoangiographic signal and identify the characteristic frequencies. A rule-based decision-making method, FPNs, is designed as a decision-making system to evaluate the degree of stenosis (DOS) in routine examinations. For 42 long-term follow-up patients, the examination results show the proposed diagnosis system has greater efficiency in evaluating AVS stenosis.

Acute aortic regurgitation caused by spontaneous aortic valve rupture

We report a rare case that manifested as severe aortic regurgitation (AR) resulting from spontaneous aortic valve (AV) rupture caused by valvular myxomatous transformation in a middle-aged woman. Before operation, 1 ruptured hole on the left coronary cusp (LLC) was clearly visualized with transesophageal echocardiography (TEE). There were no clinical findings of vegetations or sinus Valsalva aneurysms. The patient was treated successfully with mechanical AV replacement. Prompt imaging evaluation is mandatory in this rare critical situation for correct diagnosis and appropriate management.

Transaortic modification of the Viabahn open revascularization technique (VORTEC) to facilitate renal artery revascularization in a hybrid EVAR procedure

PURPOSE

To present a modification of the Viabahn open revascularization technique (VORTEC) to facilitate right renal artery (RRA) revascularization via a limited thoracotomy and transaortic sheath during endovascular aneurysm repair (EVAR).

CASE REPORT

A 51-year-old man with uncontrolled hypertension and limited respiratory reserve presented with a pararenal abdominal aortic aneurysm (AAA) measuring ∼15×8.5×8 cm extending into the iliac arteries. Via a limited low thoracoabdominal incision and retroperitoneal approach, 3 of the renovisceral branches were exposed, but there was difficulty in approaching the RRA. A handmade 4-branched polytetrafluoroethylene graft (PTFE) was anastomosed to the descending thoracic aorta, and the 3 exposed renovisceral branches were bypassed sequentially. A modification of the VORTEC with a transaortic approach to revascularize the RRA was successful; a 7-mm×10-cm Viabahn stent-graft was advanced into the RRA and deployed into the RRA limb of the PTFE graft. The Viabahn-PTFE graft junction was fixed with interrupted suture, and its transaortic portion was dilated with a 7-mm balloon. EVAR was then accomplished with a 28.5-mm Excluder stent-graft. The final angiogram documented patent bypass grafts and no endoleak. Follow-up imaging showed a satisfactory stent-graft and patent PTFE graft without undue kinking of the Viabahn or stenosis within its transaortic portion. The patient remained well after 1-year follow-up.

CONCLUSION

This transaortic modification may be a useful option for hybrid EVAR and application of a sutureless telescoping anastomosis technique.

One-stage total repair of anomalous origin of right pulmonary artery from aorta by the double-flap technique, followed by coarctation repair using extended end-to-end arch reconstruction

The anomalous origin of the right pulmonary artery from the ascending aorta combined with coarctation of aorta is a rare congenital malformation. The method chosen for performing a prompt surgery to correct the multiple disease lesions is important. Here we report one-stage surgical strategy which involved a double-flap technique alongside an extended end-to-end arch reconstruction in a newborn baby.