Successful TAVR for a Patient with Bicuspid Aortic Valve Stenosis and Previous Type A Aortic Dissection.

Whether transfemoral transcatheter aortic valve replacement (TAVR) can be accomplished in patients with a bicuspid aortic valve (AV) and previous type A aortic dissection remains rarely addressed. We report such a case in whom transfemoral TAVR was smoothly performed employing an extraordinary long sheath to bypass the dissected aortic segment, yet at the cost of perioperative left temporoparietal infarction owing to no suitable cerebral embolic protection device available in the presence of a remaining dissection in the aortic arch. Thus, for such patients, transfemoral TAVR is still feasible but novel embolic protection devices of distinct designs should be developed to avoid perioperative cerebral embolism.

Progress in the Preparation of Functional and (Bio)Degradable Polymers via Living Polymerizations.

This review presents the latest developments in (bio)degradable approaches and functional aliphatic polyesters and polycarbonates prepared by typical ring-opening polymerization (ROP) of lactones and trimethylene carbonates. It also considers several recent innovative synthetic methods including radical ring-opening polymerization (RROP), atom transfer radical polyaddition (ATRPA), and simultaneous chain- and step-growth radical polymerization (SCSRP) that produce aliphatic polyesters. With regard to (bio)degradable approaches, we have summarized several representative cleavable linkages that make it possible to obtain cleavable polymers. In the section on functional aliphatic polyesters, we explore the syntheses of specific functional lactones, which can be performed by ring-opening copolymerization of typical lactone/lactide monomers. Last but not the least, in the recent innovative methods section, three interesting synthetic methodologies, RROP, ATRPA, and SCSRP are discussed in detail with regard to their reaction mechanisms and polymer functionalities.

Effect of Retrograde Cerebral Protection Strategy on Outcome of Patients with Stanford Type A Aortic Dissection.

BACKGROUND: Neurological complications are an important concern in the repair of type A aortic dissection. Supra-aortic involvement is considered to be an important risk factor for neurological injuries. However, the optimal brain protection strategy still remains controversial. The aim of the present study was to assess the efficacy and short-term results of retrograde cerebral protection techniques in the treatment of acute type A aortic dissection. METHODS: Between 2005 and 2013, 185 patients who underwent repair of acute type A aortic dissection were enrolled in this study, all of whom received retrograde cerebral perfusion. The patients were divided into two group: 102 patients who had at least one carotid artery involved as the carotid dissection group, and 83 patients who had no carotid artery involvement as the non-carotid dissection group. RESULTS: The mean age of the patients was 57.8 years and 69% were male. The 30-day mortality rate was 10.3%, and the overall in-hospital mortality rate was 11.9%. Eight patients (4.3%) developed new permanent neurological deficits (PNDs) including two in the non-carotid dissection group and six in the carotid dissection group. Although new PND was milder in the carotid dissection group, there was no significant difference (p = 0.248). The proportion of patients who received a coronary artery bypass graft was significantly higher in the carotid dissection group (1 vs. 8, p = 0.037). CONCLUSIONS: According to our study, the retrograde cerebral perfusion technique is an easy and safe procedure, especially for patients with concomitant carotid dissection.

Rescue of Coronary Injury with Right Internal Mammary Artery Bypass during Repair of a Complex Congenital Heart.

UNLABELLED: A 10-year-old boy with polysplenia syndrome was diagnosed with complex congenital heart disease, including common atrium, bilateral superior vena cava, complete atrioventricular canal defect, severe pulmonary stenosis, interrupted inferior vena cava, and patent ductus arteriosus. Previously, he underwent a bilateral bidirectional Glenn shunt operation with ligation of the patent ductus arteriosus in April, 2009, when he was six years old. During the operation, his left anterior descending coronary artery (LAD) was injured accidently due to abnormally high coronary artery takeoff. Consequently, a coronary artery bypass graft [right internal mammary artery (RIMA) to LAD proximal, end-to-end] was performed. On July 24, 2013, he received the last stage of a total cavopulmonary connection with an extracardiac conduit (22 mm PTFE graft) at ten years of age. The RIMA was not injured during redo-sternotomy and he was discharged uneventfully 11 days after the operation. KEY WORDS: Congenital heart disease; Coronary artery bypass surgery; Coronary injury.

Excellent mid-term durability of the On-X mechanical aortic valve in the pulmonary position with a low international normalized ratio.

BACKGROUND AND AIM OF THE STUDY: Although the pulmonary position has been preferred for the placement of homografts or bioprosthetic valves, the limited longevity of these implants makes reoperation almost unavoidable. Good durability of mechanical valves in the pulmonary position has been reported. The mid-term outcomes were analyzed of patients who received an On-X mechanical heart valve for pulmonary valve replacement (PVR) with a relatively low International Normalized Ratio (INR). METHODS: Between February 2008 and February 2011, mechanical On-X valves (size range: 19 to 25 mm) were implanted for PVR in six patients. Tetralogy of Fallot (ToF) was the most common diagnosis (n = 6). Postoperatively, warfarin was used to maintain the INR at 1.5-2.0. The surgical results and follow up were reviewed retrospectively, with valve failure, thrombosis, embolism, bleeding, reoperation and death being defined as end-points. RESULTS: There was no intraoperative or in-hospital mortality. The mean age of patients at the time of PVR was 31 +/- 19.7 years (range: 16-61 years). In patients who underwent repair of ToF (n = 4) the average duration between PVR and previous right ventricular outflow tract (RVOT) reconstruction was 8.75 +/- 3.3 years (range: 5-12 years). The mean follow up period was 3.13 +/- 1.31 years (range: 2-5 years). There was no 30-day mortality, late death, thromboembolism, major bleeding event or valve dysfunction, and no patient needed reoperation. All survivors were categorized as NYHA class I or II. CONCLUSION: A three-year experience with the On-X bileaflet mechanical valve in the pulmonary position demonstrated excellent mid-term durability, with no thromboembolisms or bleeding events when the INR was maintained at 1.5-2.0. For patients who require PVR, either as primary procedure or reoperation, the On-X mechanical heart valve might represent an appropriate option.

From atretic to perforated: a closer view of pulmonary atresia.

A 7-day-old male infant with membranous pulmonary atresia and intact ventricular septum (PA/IVS) underwent hybrid pulmonary valvotomy. Access was via median sternotomy guided by intra-operative epicardial ultrasonography. After puncturing the atretic pulmonary valve, a 6 mm Wanda balloon catheter was inflated to dilate the atretic valve. Adequate valve movement with antegrade flow was confirmed using real time epicardial echocardiography. Intra-operative epicardial ultrasonography is an effective tool for guiding PA/IVS during hybrid procedures. Epicardial echo imaging provides clear images with excellent quality, helps guide the hybrid operation, and prevents the need for the ionizing radiation of fluoroscopy.

Asymptomatic Right Ventricular Perforation by a Temporary Transvenous Pacing Lead in an Infant.

UNLABELLED: A 3-month-old male infant received transvenous temporary pacemaker for acquired complete atrioventricular block. However, a right ventricle perforation by the pacing lead was found incidentally when the patient was receiving permanent pacemaker implantation nineteen days after temporary pacing. There was no pacemaker dysfunction, active bleeding or hemopericardium. The temporary pacing lead was extracted and the site of perforation was sutured. This case is unique because of the patient's unusual clinical presentation, and we suggested that echocardiography should be performed cautiously to check the pacing catheter tip daily, even if asymptomatic and/or normal function of pacemaker. KEY WORDS: Complete atrioventricular block; Right ventricle perforation; Transvenous pacing lead.

Surgical Management for Complications during Closure of Atrial Septal Defect with Amplatzer Device.

BACKGROUND: Transcatheter closure of secundum type atrial septal defect (ASD) has become a standard procedure in most medical centers. Although the procedure is invasive and has a shorter recovery duration and a lower complication rate compared with surgery, it is not risk-free. In this retrospective chart review case series, we report our experience of management of complications after placement of an ASD occluder. METHODS: Between January 2000 and December 2010, a total of 508 patients in our hospital underwent closure of secundum type ASD using an Amplatzer septal occluder (ASO). Six of the patients (1.2%) had device embolization or migration warranting surgical retrieval and repair. RESULTS: All the devices were removed and the defects were repaired successfully without any mortality. CONCLUSIONS: Surgical intervention for complications of ASO placement in patients who underwent closure of secundum type ASD is safe and effective. KEY WORDS: Amplatzer occluder; Atrial septal defect; Surgical management.

Hybrid therapy for interrupted aortic arch with aortopulmonary window in a low birth weight infant.

Interrupted aortic arch (IAA) is rarely associated with aortopulmonary window. Single-stage total correction is the preferred therapeutic option. When total correction is unfeasible, staged repair could be the therapeutic choice. Here, we presented a low birth weight infant who underwent bilateral pulmonary arteries banding and stenting ductus arteriosus by hybrid procedure. Hybrid procedure avoids long-term central line insertion and guarantees ductal flow. It also avoids the side effects from prostaglandin infusion.

Involvement of Galectin-1 Tumor Microenvironment in Radiosensitivity.

BACKGROUND/AIM: The mechanisms of galectin-1 in radioresistance may not only involve intracellular but also extracellular effects because galectin-1 can be secreted into the extracellular matrix. We, therefore, aimed to investigate the role of the galectin-1 tumor microenvironment on radiosensitivity in a murine tumor model. MATERIALS AND METHODS: Wild-type or stable galectin-1-down-regulated cancer cells (melanoma (B16F10) and lung cancer (LLC1)) were injected (subcutaneous injection) into wild-type or knockout (galectin-1, B cells, and T cells) mice that were subject to 0 or 8 Gy irradiation. RESULTS: Galectin-1-down-regulated B16F10 cells showed increased radiosensitivity when injected into galectin-1 knockout mice. Interestingly, radioresistance of wild-type LCC1 tumors was noted when injected into galectin-1 and B cell knockout mice. However, radiosensitization was observed in T cell knockout mice with wild-type LCC1 cells. CONCLUSION: The role of endogenous galectin-1 in radioresistance exists in cases without extracellular galectin-1. Extracellular galectin-1 requires endogenous galectin-1 to radiosensitize tumors in mice.

Catecholamine-Induced Secondary Takotsubo Syndrome in Children With Severe Enterovirus 71 Infection and Acute Heart Failure: A 20-year Experience of a Single Institute.

Background: Acute heart failure (AHF) is the major cause of death in children with severe enterovirus 71 (EV71) infection. This study aimed to report our clinical experience with EV71-related AHF, as well as to discuss its pathogenesis and relationship to Takotsubo syndrome (TTS). Methods: A total 27 children with EV71-related AHF between 1998 and 2018 were studied. The TTS diagnosis was based on the International Takotsubo Diagnostic Criteria. Results: Acute heart failure-related early death occurred in 10 (37%) of the patients. Sinus tachycardia, systemic hypertension, and pulmonary edema in 100, 85, and 81% of the patients, respectively, preceded AHF. Cardiac biomarkers were significantly increased in most patients. The main echocardiographic findings included transient and reversible left ventricular (LV) regional wall motion abnormality (RWMA) with apical ballooning. High concentrations of catecholamines either preceded or coexisted with AHF. Myocardial pathology revealed no evidence of myocarditis, which was consistent with catecholamine-induced cardiotoxic damage. Patients with EV71-related AHF who had received close monitoring of their cardiac function, along with early intervention involving extracorporeal life support (ECLS), had a higher survival rate (82 vs. 30%, p = 0.013) and better neurological outcomes (59 vs. 0%, p = 0.003). Conclusion: EV 71-related AHF was preceded by brain stem encephalitis-related hypercatecholaminemia, which resulted in a high mortality rate. Careful monitoring is merited so that any life-threatening cardiogenic shock may be appropriately treated. In view of the similarities in their clinical manifestations, natural course direction, pathological findings, and possible mechanisms, TTS and EV71-related AHF may represent the same syndrome. Therefore, we suggest that EV71-related AHF could constitute a direct causal link to catecholamine-induced secondary TTS.

Spherically symmetric mesenchymal stromal cell bodies inherent with endogenous extracellular matrices for cellular cardiomyoplasty.

Cell transplantation via direct intramyocardial injection is a promising therapy for patients with myocardial infarction; however, retention of the transplanted cells at the injection sites remains a central issue following injection of dissociated cells. Using a thermoresponsive hydrogel system with a multiwell structure, we successfully developed an efficient technique to generate spherically symmetric bodies of mesenchymal stromal cells (MSCs) inherent with endogenous extracellular matrices (ECMs) for direct intramyocardial injection. After injection through a needle and upon transferring to another growth surface, the time required to attach, migrate, and proliferate was significantly shorter for the MSC bodies than the dissociated MSCs. Employing a syngeneic rat model with experimental myocardial infarction, an intramyocardial injection was conducted with a needle directly into the peri-infarct areas. There were four treatment groups (n = 10): sham, phosphate-buffered saline, dissociated MSCs, and MSC bodies. The results obtained in the echocardiography and catheterization measurements demonstrated that the MSC body group had a superior heart function to the dissociated MSC group. Histologically, it was found that MSC bodies could provide an adequate physical size to entrap into the interstices of muscular tissues and offer a favorable ECM environment to retain the transplanted cells intramuscularly. Additionally, transplantation of MSC bodies stimulated a significant increase in vascular density, thus improving the cardiac function. These results indicated that the spherically symmetric bodies of MSCs developed in the study may serve as a cell-delivery vehicle and improve the efficacy of therapeutic cell transplantation.

Preparations of Tough and Conductive PAMPS/PAA Double Network Hydrogels Containing Cellulose Nanofibers and Polypyrroles.

To afford an intact double network (sample abbr.: DN) hydrogel, two-step crosslinking reactions of poly(2-acrylamido-2-methylpropanesulfonic acid) (i.e., PAMPS first network) and then poly(acrylic acid) (i.e., PAA second network) were conducted both in the presence of crosslinker (N,N'-methylenebisacrylamide (MBAA)). Similar to the two-step processes, different contents of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) oxidized cellulose nanofibers (TOCN: 1, 2, and 3 wt.%) were initially dispersed in the first network solutions and then crosslinked. The TOCN-containing PAMPS first networks subsequently soaked in AA and crosslinker and conducted the second network crosslinking reactions (TOCN was then abbreviated as T for DN samples). As the third step, various (T-)DN hydrogels were then treated with different concentrations of FeCl3(aq) solutions (5, 50, 100, and 200 mM). Through incorporations of ferric ions into (T-)DN hydrogels, notably, three purposes are targeted: (i) strengthen the (T-)DN hydrogels through ionic bonding, (ii) significantly render ionic conductivity of hydrogels, and (iii) serve as a catalyst for the forth step to proceed with in situ chemical oxidative polymerizations of pyrroles to afford polypyrrole-containing (sample abbr.: Py) hydrogels [i.e., (T-)Py-DN samples]. The characteristic functional groups of PAMPS, PAA, and Py were confirmed by FT-IR. Uniform microstructures were observed by cryo scanning electron microscopy (cryo-SEM). These results indicated that homogeneous composites of T-Py-DN hydrogels were obtained through the four-step process. All dry samples showed similar thermal degradation behaviors from the thermogravimetric analysis (TGA). The T2-Py5-DN sample (i.e., containing 2 wt.% TOCN with 5 mM FeCl3(aq) treatment) showed the best tensile strength and strain at breaking properties (i.e., σTb = 450 kPa and εTb = 106%). With the same compositions, a high conductivity of 3.34 × 10-3 S/cm was acquired. The tough T2-Py5-DN hydrogel displayed good conductive reversibility during several "stretching-and-releasing" cycles of 50-100-0%, demonstrating a promising candidate for bioelectronic or biomaterial applications.

Correctness of multi-detector-row computed tomography for diagnosing mechanical prosthetic heart valve disorders using operative findings as a gold standard.

The purpose was to compare the findings of multi-detector computed tomography (MDCT) in prosthetic valve disorders using the operative findings as a gold standard. In a 3-year period, we prospectively enrolled 25 patients with 31 prosthetic heart valves. MDCT and transthoracic echocardiography (TTE) were done to evaluate pannus formation, prosthetic valve dysfunction, suture loosening (paravalvular leak) and pseudoaneurysm formation. Patients indicated for surgery received an operation within 1 week. The MDCT findings were compared with the operative findings. One patient with a Björk-Shiley valve could not be evaluated by MDCT due to a severe beam-hardening artifact; thus, the exclusion rate for MDCT was 3.2% (1/31). Prosthetic valve disorders were suspected in 12 patients by either MDCT or TTE. Six patients received an operation that included three redo aortic valve replacements, two redo mitral replacements and one Amplatzer ductal occluder occlusion of a mitral paravalvular leak. The concordance of MDCT for diagnosing and localizing prosthetic valve disorders and the surgical findings was 100%. Except for images impaired by severe beam-hardening artifacts, MDCT provides excellent delineation of prosthetic valve disorders.

Porous tissue grafts sandwiched with multilayered mesenchymal stromal cell sheets induce tissue regeneration for cardiac repair.

AIMS: To provide the basis for uniform cardiac tissue regeneration, a spatially uniform distribution of adhered cells within a scaffold is a prerequisite. To achieve this goal, a bioengineered tissue graft consisting of a porous tissue scaffold sandwiched with multilayered sheets of mesenchymal stromal cells was developed. METHODS AND RESULTS: This tissue graft (sandwiched patch) was used to replace the infarcted wall in a syngeneic Lewis rat model with an experimentally chronic myocardial infarction (MI). There were four treatment groups (n >/= 10): sham, MI, empty patch, and sandwiched patch. After a 7 day culture of the sandwiched patch, a tissue graft with relatively uniform cell concentrations was obtained. The cells were viable and tightly adhered to the tissue scaffold, as the endogenous extracellular matrix inherent with multilayered cell sheets can act as an adhesive agent for cell attachment and retention. At retrieval, the area of the empty patch was relatively enlarged, suggesting reduced structural support, while that of the sandwiched patch remained about the same (P = 0.56). In the immunofluorescent staining, host cells together with neo-microvessels were clearly observed in the empty patch; however, there were still a large number of unfilled pores within the patch. In the sandwiched patch, besides host cells, originally seeded cells were populated within the entire patch. No apparent evidence of apoptotic cell death was found in both studied patches. Thus, the sandwiched-patch-treated hearts demonstrated a better heart function to the empty-patch-treated hearts (P < 0.05). CONCLUSION: The results demonstrated that this novel bioengineered tissue graft can serve as a useful cardiac patch to restore the dilated left ventricle and stabilize heart functions after MI.

Direct intramyocardial injection of mesenchymal stem cell sheet fragments improves cardiac functions after infarction.

AIMS: Cell transplantation is a promising approach for patients with myocardial infarction. However, following injection, retention of the transplanted cells in the injected area remains a central issue, which can be deleterious to cell transplantation therapy. We hypothesized that the use of cell sheet fragments, with the preservation of extracellular matrix (ECM), may significantly increase cell retention and thus improve cell therapy. METHODS AND RESULTS: Mesenchymal stem cell (MSC) sheet fragments with ECM were fabricated. Experimental myocardial infarction was created in male syngeneic Lewis rats. Thirty minutes after myocardial infarction, an intramyocardial injection was conducted with a needle directly into the peri-infarct areas. There were four treatment groups (n > or = 10): sham; phosphate buffered saline; dissociated MSCs; and MSC sheet fragments. Echocardiography and pressure measurements were assessed postoperatively. At retrieval, the hearts were fixed for histological evaluation. After injection, the MSC sheet fragments remained intact, while the complete cell sheets were torn into pieces. The results obtained in the echocardiography and pressure measurements revealed a superior heart function in the MSC sheet fragment group compared with the dissociated MSC group (P < 0.05). The MSC sheet fragments were able to conform and align their inherent ECM along the interstices of the muscular tissues at the injection sites, while only a few cells were identified in the dissociated MSC group at 12 weeks postoperatively. Additionally, transplantation of the MSC sheet fragments stimulated a significant increase in vascular density (P < 0.05) and enhanced the graft/host cell connection. CONCLUSION: The MSC sheet fragments may serve as a cell delivery vehicle by providing a favourable ECM environment to retain the transplanted cells and improve the efficacy of therapeutic cell transplantation.

Modified Sleeve Technique in Aortic Valve-Sparing Operation for Marfan Syndrome.

We devised a simple modification of the Florida Sleeve procedure to perform aortic valve-sparing surgery. This technique is simple, quick, effective, and safe. We used this technique in operations performed on two young patients with Marfan syndrome. The initial and short-term results were satisfactory.

Sorption equilibrium of mercury onto ground-up tree fern.

The sorption behavior of mercury at different temperatures onto ground-up tree fern was investigated. The experimental results were fitted to two two-parameter isotherms, the Freundlich and Langmuir isotherms, as well as to two three-parameter isotherms, the Redlich-Peterson and Sips isotherms to obtain the characteristic parameters of each model. A comparison of best-fitting was performed using the coefficient of determination and Chi-square test. Both the Langmuir and Redlich-Peterson isotherms were found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the saturated monolayer sorption capacity of mercury ions onto ground-up tree fern was 26.5 mg/g at 298 K. It was noted that an increase in temperature resulted in a higher mercury ion loading per unit weight of the tree fern. In addition, various thermodynamic parameters, such as DeltaG degrees, DeltaH degrees, and DeltaS degrees, were calculated and compared with the sorption of mercury by other sorbents.

In-situ biochar application conserves nutrients while simultaneously mitigating runoff and erosion of an Fe-oxide-enriched tropical soil.

Climate change gives rise to rapid degradation of rural soils in sloping subtropical and tropical areas and might further threaten environmental sustainability. In this study, we conducted an integrated evaluation of the effects of wood biochar (WB) application mixed with a green waste dreg compost (GWC) on runoff quality, soil losses, and agricultural productivity for a highly weathered tropical soil. A conventional agriculture method, in which soils are treated with anionic polyacrylamide (PAM), was also conducted for comparison. The amounts of runoff and soil loss, and nutrient retention were evaluated a year after WB application. Soil fertility was also investigated through a year pot experiment with rape (Brassica campestris L.) cultivation. Our results showed that the WB application not only effectively increased soil pH, soil organic carbon (SOC) and exchangeable K+ but also increased the production of rape plants. Significant reduction of runoff and the increases of inorganic nitrogen (IN) and total phosphorus (TP) were found in the WB-treated soil. Compared to the control, the co-application of WB and GWC, particularly for the WB at 4%, decreased runoff by 16.8%, soil loss by 25%, and IN loss (via runoff) by 41.8%. Meanwhile, compared to the control and PAM treatments, the co-application of WB and GWC improved soil acidity and the contents of SOC, IN, TP, and exchangeable K+. The co-application of WB and GWC could be an alternative agricultural strategy to obtain benefits to agricultural productivity and environmental sustainability.

Construction and characterization of fragmented mesenchymal-stem-cell sheets for intramuscular injection.

Cell transplantation via local intramuscular injection is a promising therapy. However, the cells used are usually expanded in vitro and dissociated by trypsinization, which may be harmful to the cells. In the study, a novel method for the construction of fragmented sheets of mesenchymal stem cells (MSCs) with a uniform size, without treating with any enzymes, was reported. The obtained MSC sheets preserved the intercellular junctions and endogenous extracellular matrix and kept their cell phenotype. After injection through a needle, the fragmented MSC sheets maintained intact and retained their activity upon transferring to another growth surface, while the complete cell sheets were torn into pieces. Transplantation of fragmented MSC sheets in the skeletal muscle of a syngeneic rat model via local injection was evaluated. The transplanted MSC sheets were mainly localized at the site of injection, while the dissociated MSCs were scattered around. Additionally, there were significantly more MSCs retained in the local skeletal muscle for the group injected with fragmented MSC sheets than that injected with dissociated MSCs. These results indicated that the fragmented cell sheets might be used as a novel therapeutic cell-carrier for intramuscular administration.