Enhanced Homogeneity of Moiré Superlattices in Double-Bilayer WSe2 Homostructure.

Moiré superlattices have emerged as a promising platform for investigating and designing optically generated excitonic properties. The electronic band structure of these systems can be qualitatively modulated by interactions between the top and bottom layers, leading to the emergence of new quantum phenomena. However, the inhomogeneities present in atomically thin bilayer moiré superlattices created by artificial stacking have hindered a deeper understanding of strongly correlated electron properties. In this work, we report the fabrication of homogeneous moiré superlattices with controllable twist angles using a 2L-WSe2/2L-WSe2 homostructure. By adding extra layers, we provide additional degrees of freedom to tune the optical properties of the moiré superlattices while mitigating the nonuniformity problem. The presence of an additional bottom layer acts as a buffer, reducing the inhomogeneity of the moiré superlattice, while the encapsulation effect of the additional top and bottom WSe2 monolayers further enhances the localized moiré excitons. Our observations of alternating circularly polarized photoluminescence confirm the existence of moiré excitons, and their characteristics were further confirmed by theoretical calculations. These findings provide a fundamental basis for studying moiré potential correlated quantum phenomena and pave the way for their application in quantum optical devices.

Pressure-Induced Dynamic Tuning of Interlayer Coupling in Twisted WSe2/WSe2 Homobilayers.

Moiré superlattices induced by twisted van der Waals (vdW) heterostructures or homostructures have recently gained significant attention due to their potential to generate exotic strong-correlation electronic and phonon phenomena. However, the lack of dynamic tuning for interlayer coupling of moiré superlattices hinders a thorough understanding and development of the moiré correlation state. Here, we present a dynamic tuning method for twisted WSe2/WSe2 homobilayers using a diamond anvil cell (DAC). We demonstrate the powerful tuning of interlayer coupling and observe an enhanced response to pressure for interlayer breathing modes and the rapid descent of indirect excitons in twisted WSe2/WSe2 homobilayers. Our findings indicate that the introduction of a moiré superlattice for WSe2 bilayers gives rise to hybridized excitons, which lead to the different pressure-evolution exciton behaviors compared to natural WSe2 bilayers. Our results provide a novel understanding of moiré physics and offer an effective method to tune interlayer coupling of moiré superlattices.

Observation of optical anisotropy and a linear dichroism transition in layered silicon phosphide.

The investigation of in-plane two-dimensional (2D) anisotropic materials has garnered significant attention due to their exceptional electronic, optical, and mechanical characteristics. The anisotropic optical properties and angle-dependent photodetectors based on 2D anisotropic materials have been extensively studied. However, novel in-plane anisotropic materials still need to be explored to satisfy for distinct environments and devices. Here, we report the remarkable anisotropic behavior of excitons and demonstrate a unique linear-dichroism transition of absorption between ultraviolet and visible light in layered silicon phosphide (SiP) through the analysis of polarization photoluminescence (PL) and absorbance spectra. Its high absorption linear dichroism ratio of 1.16 at 388 nm, 1.15 at 532 nm, and 1.19 at 733 nm is revealed, suggesting the brilliant non-isotropic responses. The robust periodic variation of the A1 and A2 Raman modes in 2D SiP materials allows for the determination of their crystal orientation. Furthermore, the presence of indirect excitons with phonon sidebands in the temperature-dependent PL spectra exhibits non-monotonic energy shifts with increasing temperature, which is attributed to an enhanced electron-phonon interaction and thermal expansion. Our findings provide valuable insights into the fundamental physical properties of layered SiP and offer guidelines for designing polarization-sensitive photodetectors and angle-dependent devices based on 2D anisotropic materials.

Giant uniaxial negative thermal expansion in FeZr2 alloy over a wide temperature range.

Negative thermal expansion (NTE) alloys possess great practical merit as thermal offsets for positive thermal expansion due to its metallic properties. However, achieving a large NTE with a wide temperature range remains a great challenge. Herein, a metallic framework-like material FeZr2 is found to exhibit a giant uniaxial (1D) NTE with a wide temperature range (93-1078 K, [Formula: see text]). Such uniaxial NTE is the strongest in all metal-based NTE materials. The direct experimental evidence and DFT calculations reveal that the origin of giant NTE is the couple with phonons, flexible framework-like structure, and soft bonds. Interestingly, the present metallic FeZr2 excites giant 1D NTE mainly driven by high-frequency optical branches. It is unlike the NTE in traditional framework materials, which are generally dominated by low energy acoustic branches. In the present study, a giant uniaxial NTE alloy is reported, and the complex mechanism has been revealed. It is of great significance for understanding the nature of thermal expansion and guiding the regulation of thermal expansion.

Is the Mid-Term Patency Rate of Small-Diameter Viabahn Stent-Grafts in Peripheral Artery Disease Related to Their Length? A Systematic Review.

OBJECTIVE: Small-diameter endografts can be used for the treatment of the peripheral vascular disease, but the patency rate during the follow-up is still under debate. With this review, we aimed at analyzing the mid-term patency of small-diameter Viabahn stent-grafts and investigating the relationship between patency and the length of the graft. METHODS: We performed a review of articles published until September 2020 and reporting use of ≤7-mm-diameter Viabahn stent-grafts in diseased peripheral arteries. Data on study type, demographic, lesion length, stent-graft diameter, length, and patency (1-year, 3-year, 5-year primary patency, primary-assisted patency, and secondary patency), follow-up, endoleak, and re-intervention rates were extracted and analyzed. A statistical test was applied to identify a correlation between stent-graft length and patency. RESULTS: 16 retrospective and 7 prospective studies reported the outcome of 1613 patients (mean age: 69.6±33.7 years). There was considerable heterogeneity in reporting standards among studies. The diameter of Viabahn stent-grafts ranged 5 to 7mm and the average length was 23.6±12.4cm. Heparin-bonded grafts were used in 46.4% of cases. Mean follow-up time was 26.4±17.6 months. The 1- and 5-year primary patency rate was 75.7% (95% CI, 73.6%-77.8%) and 46.8% (95% CI, 41.0%-52.6%), respectively. The 1- and 5-year primary-assisted patency rate was 80.9% (95% CI, 73.9%-87.8%) and 60.9% (95% CI, 46.4-75.5%), respectively. The 1- and 5-year second-assisted patency was 90.4% (95% CI, 87.4%-93.3%) and 73.7% (95% CI, 64.7%-82.8%), respectively. No correlation between the stent-graft length and patency was found. CONCLUSIONS: Small-diameter Viabahn stent-graft implantation represents a safe treatment for patients with peripheral artery disease, and the mid-term patency rate seems not be affected by the length of the graft. CLINICAL IMPACT: The use of small diameter stent-grafts for peripheral vascular disease is an established technique but the patency rate is still under debate. With this review we have investigated the relationship between the mid-term patency and the diameter of the stent-grafts. Afterv having analysed data from 23 published studies including 1613 patients we can conclude that the treatment of the peripheral artery disease with small diameter stent-grafts is safe and the mid-term patency rate seems not be affected by the lenght of the grafts.

Strain-tunable valley polarization and localized excitons in monolayer WSe2.

Monolayer transition metal dichalcogenides (TMDs) have a crystalline structure with broken spatial inversion symmetry, making them promising candidates for valleytronic applications. However, the degree of valley polarization is usually not high due to the presence of intervalley scattering. Here, we use the nanoindentation technique to fabricate strained structures of WSe2 on Au arrays, thus demonstrating the generation and detection of strained localized excitons in monolayer WSe2. Enhanced emission of strain-localized excitons was observed as two sharp photoluminescence (PL) peaks measured using low-temperature PL spectroscopy. We attribute these emerging sharp peaks to excitons trapped in potential wells formed by local strains. Furthermore, the valley polarization of monolayer WSe2 is modulated by a magnetic field, and the valley polarization of strained localized excitons is increased, with a high value of up to approximately 79.6%. Our results show that tunable valley polarization and localized excitons can be realized in WSe2 monolayers, which may be useful for valleytronic applications.

Localization-enhanced moiré exciton in twisted transition metal dichalcogenide heterotrilayer superlattices.

The stacking of twisted two-dimensional (2D) layered materials has led to the creation of moiré superlattices, which have become a new platform for the study of quantum optics. The strong coupling of moiré superlattices can result in flat minibands that boost electronic interactions and generate interesting strongly correlated states, including unconventional superconductivity, Mott insulating states, and moiré excitons. However, the impact of adjusting and localizing moiré excitons in Van der Waals heterostructures has yet to be explored experimentally. Here, we present experimental evidence of the localization-enhanced moiré excitons in the twisted WSe2/WS2/WSe2 heterotrilayer with type-II band alignments. At low temperatures, we observed multiple excitons splitting in the twisted WSe2/WS2/WSe2 heterotrilayer, which is manifested as multiple sharp emission lines, in stark contrast to the moiré excitonic behavior of the twisted WSe2/WS2 heterobilayer (which has a linewidth 4 times wider). This is due to the enhancement of the two moiré potentials in the twisted heterotrilayer, enabling highly localized moiré excitons at the interface. The confinement effect of moiré potential on moiré excitons is further demonstrated by changes in temperature, laser power, and valley polarization. Our findings offer a new approach for localizing moiré excitons in twist-angle heterostructures, which has the potential for the development of coherent quantum light emitters.

Moiré Enhanced Potentials in Twisted Transition Metal Dichalcogenide Trilayers Homostructures.

The exploration of moiré superlatticesholds promising potential to uncover novel quantum phenomena emerging from the interplay of atomic structure and electronic correlation . However, the impact of the moiré potential modulation on the number of twisted layers has yet to be experimentally explored. Here, this work synthesizes a twisted WSe2 homotrilayer using a dry-transfer method and investigates the enhancement of the moiré potential with increasing number of twisted layers. The results of the study reveal the presence of multiple exciton resonances with positive or negative circularly polarized emission in the WSe2 homostructure with small twist angles, which are attributed to the excitonic ground and excited states confined to the moiré potential. The distinct g-factor observed in the magneto-optical spectroscopy is also shown to be a result of the confinement of the exciton in the moiré potential. The moiré potential depths of the twisted bilayer and trilayer homostructures are found to be 111 and 212 meV, respectively, an increase of 91% from the bilayer structure. These findings demonstrate that the depth of the moiré potential can be manipulated by adjusting the number of stacked layers, providing a promising avenue for exploration into highly correlated quantum phenomena.

Twisted bilayer zigzag-graphene nanoribbon junctions with tunable edge states.

Stacking two-dimensional layered materials such as graphene and transitional metal dichalcogenides with nonzero interlayer twist angles has recently become attractive because of the emergence of novel physical properties. Stacking of one-dimensional nanomaterials offers the lateral stacking offset as an additional parameter for modulating the resulting material properties. Here, we report that the edge states of twisted bilayer zigzag graphene nanoribbons (TBZGNRs) can be tuned with both the twist angle and the stacking offset. Strong edge state variations in the stacking region are first revealed by density functional theory (DFT) calculations. We construct and characterize twisted bilayer zigzag graphene nanoribbon (TBZGNR) systems on a Au(111) surface using scanning tunneling microscopy. A detailed analysis of three prototypical orthogonal TBZGNR junctions exhibiting different stacking offsets by means of scanning tunneling spectroscopy reveals emergent near-zero-energy states. From a comparison with DFT calculations, we conclude that the emergent edge states originate from the formation of flat bands whose energy and spin degeneracy are highly tunable with the stacking offset. Our work highlights fundamental differences between 2D and 1D twistronics and spurs further investigation of twisted one-dimensional systems.

Management of left subclavian artery in type B aortic dissection treated with thoracic endovascular aorta repair.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) has been the favored approach for the treatment of type B aortic dissection (TBAD). To obtain an adequate proximal landing zone, coverage of the left subclavian artery (LSA) will often be necessary. The occurrence of possible neurologic complications has continued to be debated. We investigated the management of the LSA in patients with TBAD undergoing endovascular repair. METHODS: We searched the PubMed and MEDLINE databases to October 2020 for studies of TEVAR for TBAD. Data on the study design, demographics, endograft details, LSA coverage and revascularization, mortality, complications, and follow-up were extracted and analyzed. The effects of LSA coverage and revascularization on neurologic complications and outcomes were investigated. RESULTS: A total of 26 reports (24 retrospective and 2 prospective) were deemed eligible for our study. A total of 1483 patients (mean age, 56.9 ± 6.2 years) had undergone TEVAR for acute (n = 932; 62.9%), subacute (n = 36; 2.4%), or chronic (n = 515; 34.7%) TBAD, with a success rate of 97.8% and hospital mortality of 4.9%. The LSA origin had been covered for 707 patients (47.7%), and 326 had undergone LSA revascularization (surgical, n = 96; endovascular, n = 170; unspecified or not reported, n = 60). LSA revascularization was concomitant for 68.1% of cases, after TEVAR for 1.8%, and not reported for 30.1%. Of 1146 patients, 10 (0.9%) had experienced left arm claudication, and the overall stroke rate was 3.3% (2.7% for the LSA group and 1% for the uncovered LSA group; P = .0815). Of the patients with stroke and a covered LSA, 1% (2 of 203) had undergone LSA revascularization and 4.8% (5 of 105) had not (P = .0478). Twenty-six patients (1.9%) had developed paraplegia: 0.7% (3 of 433) with a covered LSA, 1.4% (7 of 491) with an uncovered LSA (P = .3508), and not reported for 16 patients. Endoleak was present in 138 patients (13.4%) at a mean follow-up of 32.1 ± 25.6 months. CONCLUSIONS: Our review has shown that LSA coverage during endovascular repair for complicated TBAD will does not significantly increase the risk of neurologic complications; however, revascularization of the LSA should be always recommended.

Biliverdin incorporation into the cyanobacteriochrome SPI1085g3 from Spirulina.

Cyanobacteriochromes (CBCRs) bind linear tetrapyrrole chromophores, mostly phycocyanobilin (PCB), and exhibit considerable spectral diversity with a high potential for biotechnological applications. Particular attention has been given to the conversion into intrinsic biliverdin (BV) incorporation due to the absence of PCB in mammalian cells. Our recent study discovered that a red/green CBCR of Spirulina subsalsa, SPI1085g3, was covalently attached to PCB and exhibited strong red fluorescence with a unique red/dark switch. In this study, we found that SPI1085g3 could be modestly chromophorylated with BV and absorb somewhat shifted (10 nm) red light, while the single C448S mutant could efficiently bind BV and exhibit unidirectional photoconversion and moderate dark reversion. The fluorescence in its dark-adapted state was switched off by red light, followed by a moderate recovery in the dark, and these were properties similar to those of PCB-binding SPI1085g3. Furthermore, by introducing the CY motif into the conserved CH motif for chromophore attachment, we developed another variant, C448S_CY, which showed increased BV-binding efficiency. As expected, C448S_CY had a significant enhancement in fluorescence quantum yield, reaching that of PCB-binding SPI1085g3 (0.14). These BV-binding CBCRs offer an improved platform for the development of unique photoswitchable fluorescent proteins compared with PCB-binding CBCRs.

Surgical treatment of type A acute aortic dissection with cerebral malperfusion: a systematic review.

OBJECTIVES: Type A acute aortic dissection (TAAAD) complicated with cerebral malperfusion (CM) is a life-threatening condition associated with high mortality, poor outcomes, and the optimal surgical management remains controversial. The aim of this review was to report the current results of surgical interventions of these patients. METHODS: A systematic review was performed using PubMed and MEDLINE search for cases underwent surgical repair for TAAAD with CM. Demographics, neurological symptom, the time from onset of symptoms to operation, operation data, mortality, neurological outcome, and follow-up were reviewed. RESULTS: A total of 363 patients with mean age of 65.7 ± 13 years underwent surgical repair for TAAAD with CM were identified in 12 retrospective studies. In-hospital mortality was 20.1%. Mean duration of follow-up was 40.1 ± 37.6 months. The involved supra-aortic branch vessels were RCCA (n = 99), LCCA (n = 25), B-CCA (n = 52), CCA (n = 131), IA (n = 19), and LSA (n = 8). Time from onset of neurological symptoms to surgery was 13.3 h. Antegrade and/or retrograde cerebral perfusion were applied. Postoperatively, improved, unchanged and worsened neurological status was occurred in 54.3%, 27.1%, and 8.5%, respectively in 199 patients. CONCLUSION: The outcomes of surgical treatment of TAAAD complicated with CM indicate acceptable early mortality and morbidity. It is reasonable to perform lifesaving surgery on these patients. Early central surgical repair and reperfusion of brain may improve the outcomes.

Predicting Range of Initial Warfarin Dose Based on Pharmacometabolomic and Genetic Inputs.

Anticoagulation response to warfarin during the initial stage of therapy varies among individuals. In this study, we aimed to combine pharmacometabolomic and pharmacogenetic data to predict interindividual variation in warfarin response, and, on this basis, suggest an initial daily dose range. The baseline metabolic profiles, genotypes, and clinical information of 160 patients with heart valve disease served as the variables of the function of the last international normalized ratio measured before a patient's discharge (INRday7 ) to screen for potential biomarkers. The partial least-squares model showed that two baseline metabolites (uridine and guanosine), one single-nucleotide variation (VKORC1), and four clinical parameters (weight, creatinine level, amiodarone usage, and initial daily dose) had good predictive power for INRday7 (R2  = 0.753 for the training set, 0.643 for the test set). With these biomarkers, a machine learning algorithm (two-dimensional linear discriminant analysis-multinomial logit model) was used to predict the subgroups with extremely warfarin-sensitive or less warfarin-sensitive patients with a prediction accuracy of 91% for the training set and 90% for the test set, indicating that individual responses to warfarin could be effectively predicted. Based on this model, we have successfully designed an algorithm,"IniWarD," for predicting an effective dose range in the initial 7-day warfarin therapy. The results indicate that the daily dose range suggested by the IniWarD system is more appropriate than that of the conventional genotype-based method, and the risk of bleeding or thrombus due to warfarin could thus be avoided.

Endovascular treatment of the dissected proximal aortic arch: a systematic review.

OBJECTIVES: Surgical repair of aortic dissection involving the proximal aortic arch is associated with higher morbidity and mortality, in particular when elderly high-risk patients are concerned. Endovascular treatments for this disease are under evaluation and some reports exist. We investigated the current use of catheter-based treatments for the dissected proximal aortic arch repair. METHODS: We searched in PubMed and MEDLINE databases up to the end of June 2020 for studies on endovascular treatment of the dissected proximal aortic arch. Data on demographic, procedure and stent graft (SG) details, access route, mortality with cause of death, complications and follow-up were extracted. A systematic review on the employed technology, procedure and outcome was performed. RESULTS: A total number of 15 articles (13 retrospective reports and 2 case reports) were deemed eligible and were included in the study. In total, 140 patients (mean age: 56.7 years in 106 cases) received endovascular treatments for the dissected proximal aortic arch (unspecific aortic dissection: 14; acute and subacute type A aortic dissection: 88; chronic type A aortic dissection: 23; type B aortic dissection with retrograde type A dissection: 15). The procedure strategy included unspecific thoracic endovascular aorta repair (TEVAR) (n = 8), TEVAR + supra-aortic debranching (n = 2), TEVAR + cervical bypass (n = 8), TEVAR + periscope SG (n = 12), TEVAR + chimney graft (n = 8), TEVAR + branched SG (n = 21) and TEVAR + fenestration (n = 81). Procedural success rate was 95.6% for 116 reported cases. Complications included endoleaks (postoperative: 2; late: 5), stroke (n = 4), late SG-induced new entry (n = 3) and new false lumen formation (n = 1). Hospital mortality was 5% (6 cases) in 13 reports (120 patients). The mean follow-up time was 26.2 ± 29.4 months and 2 patients died during follow-up. CONCLUSIONS: As an alternative to surgery for high-risk patients with a dissected proximal aortic arch, the endovascular treatment seems to be promising in highly selected cases. Further studies with long-term results and specifically designed devices are required to standardize this approach.

Monoclinic EuSn_{2}As_{2}: A Novel High-Pressure Network Structure.

The layered crystal of EuSn_{2}As_{2} has a Bi_{2}Te_{3}-type structure in rhombohedral (R3[over ¯]m) symmetry and has been confirmed to be an intrinsic magnetic topological insulator at ambient conditions. Combining ab initio calculations and in situ x-ray diffraction measurements, we identify a new monoclinic EuSn_{2}As_{2} structure in C2/m symmetry above ∼14 GPa. It has a three-dimensional network made up of honeycomblike Sn sheets and zigzag As chains, transformed from the layered EuSn_{2}As_{2} via a two-stage reconstruction mechanism with the connecting of Sn-Sn and As-As atoms successively between the buckled SnAs layers. Its dynamic structural stability has been verified by phonon mode analysis. Electrical resistance measurements reveal an insulator-metal-superconductor transition at low temperature around 5 and 15 GPa, respectively, according to the structural conversion, and the superconductivity with a T_{C} value of ∼4 K is observed up to 30.8 GPa. These results establish a high-pressure EuSn_{2}As_{2} phase with intriguing structural and electronic properties and expand our understandings about the layered magnetic topological insulators.

Catheter-based treatment of the dissected ascending aorta: a systematic review.

OBJECTIVES: Type A aortic dissection requires immediate surgical repair. Despite improvements in surgery and anaesthesia, there is still a considerable risk when high-risk patients are concerned. Less invasive endovascular treatments are under evaluation. We investigated the current status of catheter-based treatment for type A aortic dissection with the entry tear located in the ascending aorta. METHODS: A PubMed search was supplemented by searching through bibliographies and key articles. Demographics, risk score, stent graft detail, access route, mortality, cause of death, complications, reinterventions and follow-up data were extracted and analysed. RESULTS: Thirty-one articles (7 retrospective reports; 24 case reports/series) were included in the study. In total, 104 patients (mean age 71 ± 14 years) received endovascular treatment for acute (63) or chronic (41) type A dissection. A history of a major cardiac or aortic operation was present in 29 patients. The mean EuroSCORE II was 30 ± 20 in 4 reports. A total of 114 stent grafts were implanted: 'off-the-shelf', 65/114; custom made, 12/114; and modified, 7/114. Hospital complications included intraprocedural conversion to open surgery (2/104), stroke (2/104), coronary stenting (2/104), early endoleak (9/104) and repeat aortic endovascular treatment for endoleak (5/104). Hospital mortality was 10% (intraoperative death 2/104). Mean duration of follow-up time was 21 ± 21 months (range 1-81 months); follow-up data were available for 86 patients: 10 patients died of non-aortic-related causes; reintervention for aortic disease (endovascular repair or open surgery) was performed in 8 patients. CONCLUSIONS: Catheter-based ascending aorta repair for type A aortic dissection with the entry tear in the ascending aorta can be considered in carefully selected high-risk patients. Further analysis and specifically designed devices are required.

Extracorporeal membrane oxygenation in trauma patients: a systematic review.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has evolved considerably over the past two decades and has been gradually utilized in severe trauma. However, the indications for the use of ECMO in trauma remain uncertain and the clinical outcomes are different. We performed a systematic review to provide an overall estimate of the current performance of ECMO in the treatment of trauma patients. MATERIALS AND METHODS: We searched PubMed and MEDLINE databases up to the end of December 2019 for studies on ECMO in trauma. The PRISMA statement was followed. Data on demographics of the patient, mechanism of injury, injury severity scores (ISS), details of ECMO strategies, and clinical outcome were extracted. RESULTS: A total of 58 articles (19 retrospective reports and 39 case reports) were deemed eligible and included. In total, 548 patients received ECMO treatment for severe trauma (adult 517; children 31; mean age of adults 34.9 ± 12.3 years). Blunt trauma (85.4%) was the primary injury mechanism, and 128 patients had traumatic brain injury (TBI). The mean ISS was 38.1 ± 15.0. A total of 71.3% of patients were initially treated with VV ECMO, and 24.5% were placed on VA ECMO. The median time on ECMO was 9.6 days, and the median time to ECMO was 5.7 days. A total of 60% of patients received initially heparin anticoagulation. Bleeding (22.9%) and thrombosis (19%) were the most common complications. Ischemia of the lower extremities occurred in 9 patients. The overall hospital mortality was 30.3%. CONCLUSIONS: ECMO has been gradually utilized in a lifesaving capacity in severe trauma patients, and the feasibility and advantages of this technique are becoming widely accepted. The safety and effectiveness of ECMO in trauma require further study. Several problems with ECMO in trauma, including the role of VA-ECMO, the time to institute ECMO, and the anticoagulation strategy remain controversial and must be solved in future studies.

3D printing in adult cardiovascular surgery and interventions: a systematic review.

3D printing in adult cardiac and vascular surgery has been evaluated over the last 10 years, and all of the available literature reports benefits from the use of 3D models. In the present study, we analyzed the current applications of 3D printing for adult cardiovascular disease treated with surgical or catheter-based interventions, including the clinical medical simulation of physiological or pathology conducted with 3D printing in this field. A search of PubMed and MEDLINE databases were supplemented by searching through bibliographies of key articles. Thereafter, data on demographic, clinical scenarios and application, imaging modality, purposes of using with 3D printing, outcomes and follow-up were extracted. A total of 43 articles were deemed eligible and included. 296 patients (mean age: 65.4±14.2 years; male, 58.2%) received 3D printing for cardiac and vascular surgery or conditions [percutaneous left atrial appendage occlusion (LAAO), TAVR, mitral valve disease, aortic valve replacement, coronary artery abnormality, HOCM, aortic aneurysm and aortic dissection, Kommerell's diverticulum, primary cardiac tumor and ventricular aneurysm]. Eight papers reported the utility of 3D printing in the medical simulator and training fields. Most studies were conducted starting in 2014. Twenty-six was case report. The major scenario used with 3D printing technology was LAAO (50.3%) and followed by TAVR (17.6%). CT and echocardiography were two main imaging techniques that were used to generate 3D-printed heart models. All studies showed that 3D-printed models were helpful for preoperative planning, orientation, and medical teaching. The important finding is that 3D printing provides a unique patient-specific method to assess complex anatomy and is helpful for intraoperative orientation, decision-making, creating functional models, and teaching adult cardiac and vascular surgery, including catheter-based heart surgery.

Chimney grafts in renal arteries: a clinical model for coronary perfusion in future transcatheter aortic root repair techniques.

OBJECTIVES: Given the similarities between coronary ostia and renal arteries, chimney grafts (CG) for kidney perfusion during abdominal endovascular aneurysm repair (EVAR) can be considered for coronary perfusion in future transcatheter aortic root repair (TARR) techniques. We analysed the results of renal CG and compared anatomic and technical details with root and coronary anthropometric data. METHODS: Current status of kidney perfusion with CG was reviewed from literature. Anatomic details, technical data, CG performance and clinical outcome were collected and analysed. Anatomic details of aortic landing zone and renal arteries were compared with human anthropometric data of aortic root, ascending aorta and coronary ostia. RESULTS: Seventeen articles reported 430 patients (mean age:74.5 ± 2.9 years) treated with renal CG. Mean length and diameter of proximal landing zone were 2.0 ± 2.0 mm and 26.4 ± 4.3 mm, respectively (anthropometric correspondence: ascending aorta diameter of 29.3 mm). Aortic endograft mean diameter was 26.4 ± 7.3 mm with reported oversize of 19.5 ± 6.0%. In total, 590 renal arteries were treated (left:325; right:265; bilateral:139 cases). Mean left and right renal artery diameters were 5.7 ± 0.6 mm and 5.8 ± 0.7 mm, respectively (anthropometric correspondence: coronary ostia diameters of 4.8 mm (left) and 3.7 mm (right)) with reported CG oversize of 19.75 ± 6% (left) and 18.1 ± 5.1% (right). Mean follow-up time was 16.5 ± 8.5 months, CG occlusion rate was 3.2% and endoleak I or II was reported in 83 patients (19.3%), requiring 7 procedures. CONCLUSIONS: CG provides satisfactory results in patients with suitable renal artery diameter. Based on aortic root and coronary anthropometric data, CG can be considered in future TARR technologies for coronary perfusion but further tests for flow evaluations are mandatory.

Cox-maze III procedure for atrial fibrillation during valve surgery: a single institution experience.

OBJECTIVES: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in patients with heart valve disease. Our aim was to summarize our experience and evaluate the efficacy and safety of the Cox maze III procedure combined with valve surgery in patients with AF. METHODS: A retrospective, observational analysis was performed for all consecutive patients underwent maze III procedure combined with valve surgery between October 2015 and June 2019. In this trial, we used a monopolar radiofrequency (RF) ablation in addition to cut and sew technique to treat AF. RESULTS: 66 patients (37 female, 56.1%) with persistent or long-lasting persistent AF associated with valve disease were identified. The mean age was 54.2 ± 8.4 years (range, 30 to 73 years). Overall hospital mortality was 3.0%. The duration of cardiopulmonary bypass and aortic cross clamping was 175.4 ± 32.9 and 115.6 ± 22.8 min respectively. The first 24 h drainage was 488.6 ± 293.3 ml. The postoperative hospital stay was 14.8 ± 8.3 days. The postoperative incidence of permanent pacemaker implantation, reoperation for bleeding, renal failure required hemodialysis, and stroke was 4.5, 1.5, 4.5% and 0 respectively. The frequency of sinus rhythm was 91.7, 93.1, 94.7, 93.3 and 89.5% at 1, 3, 6, 12, and 24 months respectively. CONCLUSIONS: The Cox-Maze III procedure is safe in the surgical treatment of AF associated with valve disease, and efficacious for sinus rhythm maintenance, with low morbidity and mortality.