Left ventricular unloading therapy using Impella 5.5 after emergency surgery for acute myocardial infarction mechanical complication: a case report.

BACKGROUND: Following an acute myocardial infarction (AMI), surgery for left ventricular free wall rupture (LVFWR) and ventricular septal rupture (VSR) has a high in-hospital mortality rate, which has not improved significantly over time. Unloading the LV is critical to preventing excessive stress on the repair site and avoiding problems such as bleeding, leaks, patch dehiscence, and recurrence of LVFWR and VSR because the tissue is so fragile. We present two cases of patients who used Impella 5.5 for LV unloading following emergency surgery for AMI mechanical complications. CASE PRESENTATION: A 76-year-old male STEMI patient underwent fibrinolysis of the distal right coronary artery. Three days later, he passed out and went into shock. Echocardiography revealed a cardiac tamponade. We found an oozing-type LVFWR on the posterolateral wall and treated it with a non-suture technique using TachoSil. Before the patient was taken off CPB, Impella 5.5 was inserted into the LV via a 10 mm synthetic graft connected to the right axillary artery. We kept the flow rate above 4.0 to 4.5 L/min until POD 3 to reduce LV wall tension while minimizing pulsatility. On POD 6, we weaned the patient from Impella 5.5. A postoperative cardiac CT scan showed no contrast leakage from the LV. However, a cerebral hemorrhage on POD 4 during heparin administration complicated his hospitalization. Case 2: A diagnosis of cardiogenic shock caused by STEMI occurred in an 84-year-old male patient, who underwent PCI of the LAD with IABP support. Three days after PCI, echocardiography revealed VSR, and the patient underwent emergency VSR repair with two separate patches and BioGlue applied to the suture line between them. Before weaning from CPB, we implanted Impella 5.5 in the LV and added venoarterial extracorporeal membrane oxygenation (VA-ECMO) support for right heart failure. The postoperative echocardiography revealed no residual shunt. CONCLUSIONS: Patients undergoing emergency surgery for mechanical complications of AMI may find Impella 5.5 to be an effective tool for LV unloading. The use of VA-ECMO in conjunction with Impella may be an effective strategy for managing VSR associated with concurrent right-sided heart failure.

Design of closed loop for reproduction of gas-dominated hydrate flow.

The study presents a novel setup for measuring the flow regime of hydrate particles in a gas-dominated flow, which is of interest for applications such as natural gas transportation. A closed-flow loop, driven by a novel internal fan, enables continuous observation of hydrate particle behavior in a gas flow. The experimental setup allows the production and insertion of HFC134a gas hydrate particles with diameters of 10-50 µm into the gas flow loop via a bypass loop. The performance curve of the internal fan is validated, and its suitability for achieving the required flow speed (5 m/s) is demonstrated. Through an observation window using camera systems, the flow regime of glass beads is successfully visualized and analyzed. To validate the experimental data, a coupled computational fluid dynamics-discrete element method model is used to simulate the particle flow density distribution. The study findings demonstrate the effectiveness of the experimental setup in characterizing the flow regime of hydrate particles in a gas-dominated flow.

[Right Atrial Blood Cyst with Patent Foramen Ovale:Report of a Case].

A woman in 70s was diagnosed with lung cancer, and a right atrial mass was discovered incidentally during preoperative examination by contrast-enhanced computed tomography (CT). Transesophageal echocardiography revealed a 20-mm, stemmed, spherical mass with low internal echogenicity and partially high echogenicity extending from the junction of the inferior vena cava to the posterior wall of the right atrium. Patent foramen ovale( PFO) was also confirmed. To avoid embolization and obtain diagnosis, the patient was referred for right atrial tumor resection. Cardiopulmonary bypass was established; the right atrial tumor was removed while the patient was in cardiac arrest. The tumor membrane was thin and easily ruptured, revealing jelly-like blood content and calcified mass. The patient recovered well after surgery and was discharged on day 15. According to the pathological examination, the tumor was a blood cyst. This is an extremely rare case of a blood cyst with PFO.

Total arch replacement and frozen elephant trunk for acute type A aortic dissection.

OBJECTIVE: The present study aimed to evaluate the outcomes of total aortic arch replacement with proximalization of distal anastomosis using the frozen elephant trunk technique with the J Graft FROZENIX (Japan Lifeline, Tokyo, Japan) and Gelweave Lupiae (Vascutek Terumo Inc, Scotland, United Kingdom) graft (distal anastomosis performed in zones 1 and 2) in patients with acute Stanford type A acute aortic dissection. METHODS: A total of 50 patients underwent total aortic arch replacement using the frozen elephant trunk technique, deploying the J Graft FROZENIX into zone 1 or 2 (zone 1: n = 17, zone 2: n = 33) in combination with the Gelweave Lupiae graft for acute Stanford type A acute aortic dissection. Patient characteristics, intraoperative data, and early and midterm outcomes were analyzed. RESULTS: The overall in-hospital mortality rate was 4% (2 patients). The in-hospital mortality rate in patients with visceral malperfusion was 11% (1/9). There were no patients with paraplegia and stent graft-induced new entry. Resection or closure of the most proximal entry tear was achieved in 100% of 42 patients who had postoperative computed tomography. The overall survival was 87.9%, 84.1%, and 84.1% at 1, 2, and 3 years, respectively. However, 1 patient required endovascular extension for the dilatation of the descending thoracic aorta 4 months after the initial surgery. CONCLUSIONS: Total aortic arch replacement with the frozen elephant trunk technique (zone 1-2) and Gelweave Lupiae graft was safe and effective in simplifying surgery for acute Stanford type A acute aortic dissection.

Diamond formation from methane hydrate under the internal conditions of giant icy planets.

Hydrocarbon chemistry in the C-O-H system at high pressure and high temperature is important for modelling the internal structure and evolution of giant icy planets, such as Uranus and Neptune, as their interiors are thought to be mainly composed of water and methane. In particular, the formation of diamond from the simplest hydrocarbon, i.e., methane, under the internal conditions of these planets has been discussed for nearly 40 years. Here, we demonstrate the formation of diamond from methane hydrate up to 3800 K and 45 GPa using a CO2 laser-heated diamond anvil cell combined with synchrotron X-ray diffraction, Raman spectroscopy, and scanning electron microscopy observations. The results show that the process of dissociation and polymerisation of methane molecules to produce heavier hydrocarbons while releasing hydrogen to ultimately form diamond proceeds at milder temperatures (~ 1600 K) and pressures (13-45 GPa) in the C-O-H system than in the C-H system due to the influence of water. Our findings suggest that diamond formation can also occur in the upper parts of the icy mantles of giant icy planets.

Recovery of N2O: Energy-Efficient and Structure-Driven Clathrate-Based Greenhouse Gas Separation.

N2O has 300 times more global warming potential than CO2 and is also one of the main stratospheric ozone-depleting substances emitted by human activities such as agriculture, industry, and the combustion of fossil fuels and solid waste. We present here an energy-efficient clathrate-based greenhouse gas-separation (CBGS) technology that can operate at room temperature for selectively recovering N2O from gas mixtures. Clathrate formation between α-form/ß-form hydroquinone (α-HQ/ß-HQ) and gas mixtures reveals guest-specific and structure-driven selectivity, revealing the preferential capture of N2O in ß-HQ and the molecular sieving characteristics of α-HQ. With a maximum gas storage capacity and cage occupancy of 54.1 cm3 g-1 and 0.86, respectively, HQ clathrate compounds including N2O are stable at room temperature and atmospheric pressure and thus can be easily synthesized, treated, and recycled via commercial CBGS processes. High selectivity for N2O recovery was observed during ß-HQ clathrate formation from N2O/N2 gas mixtures with N2O concentrations exceeding 20%, whereas α-HQ traps only N2 molecules from gas mixtures. Full characterization using X-ray diffraction, scanning electron microscopy, Raman spectroscopy, solid-state nuclear magnetic resonance, and compositional analysis and the formation kinetics of HQ clathrates was conducted to verify the peculiar selectivity behavior and to design the conceptual CBGS process. These results provide a new playground on which to tailor host-guest materials and develop commercial processes for the recovery and/or sequestration of greenhouse gases.

Cardiac haemangioma treated with surgical resection involving reconstruction of the right ventricle.

A right ventricular cardiac tumour was incidentally detected in a 50-year-old woman during medical check-up. Transthoracic echocardiography, computed tomography and magnetic resonance imaging revealed that the right ventricular tumour was widely attached to the free wall of the right ventricle and extended to the right ventricular outflow tract. The tumour was excised surgically, and the postoperative course was uneventful. Histological examination revealed that the tumour was a cardiac haemangioma.

Partial aortic root remodeling for chronic aortic dissection with coronary intimal tear.

While there are many reports on partial aortic root remodeling, it is rarely performed for chronic aortic dissection of the coronary artery. This report presents a case of a 69-year-old man incidentally diagnosed with aortic dissection during routine checkup. He had a history of percutaneous coronary intervention from the left main trunk to the left anterior descending artery and left circumflex artery. Computed tomography revealed a chronic type A aortic dissection with an aneurysmal aortic root. The false lumen of the Valsalva sinus originated from the left anterior descending artery and expanded largely to the non-coronary Valsalva sinus. We performed partial aortic root remodeling, resecting the dissected non-coronary Valsalva sinus. The postoperative course was uneventful. Partial aortic root remodeling was effective, but its use might be controversial for chronic aortic dissection without resection of the primary entry of the left anterior descending artery. Moreover, close follow-up is required.

Effect of Ammonia on Methane Hydrate Stability under High-Pressure and High-Temperature Conditions.

High-pressure experiments were conducted to investigate the stability and phase transition of methane hydrate (MH) in the water-methane-ammonia system at room-to-high temperatures employing Raman spectroscopy and synchrotron X-ray powder diffraction, in combination with an externally heated diamond anvil cell. The results revealed that, at room temperature, MH undergoes phase transitions from MH-I to MH-II at ∼1.0 GPa and from MH-II to MH-III at ∼2.0 GPa. These transition behaviors are consistent with those in the water-methane system, which indicates that ammonia has a negligible effect on a series of phase transitions of MH. Contrarily, a sequential in situ Raman spectroscopy revealed that ammonia affects the stability of MH-III under high pressure and high temperature: the dissociation temperature of MH-III was more than 10 K lower in the water-methane-ammonia system than in the water-methane system. These findings aid in improving the internal structural models of icy bodies and estimating the origin of their atmospheric methane.

Thoracic endovascular aortic repair for an ascending aortic pseudoaneurysm.

An 80-year-old woman underwent aortic valve replacement and ascending aortic replacement. Two years later, computed tomography revealed a pseudoaneurysm of the ascending aorta replaced with a prosthesis. The pseudoaneurysm arose from the stump of a side branch of the prosthesis. Endovascular treatment for the pseudoaneurysm was carried out using the aortic extension cuff of an infrarenal endovascular system. The postoperative course was uneventful.

CO2 Capture from Flue Gas Based on Tetra-n-butylammonium Fluoride Hydrates at Near Ambient Temperature.

Semiclathrate hydrates of tetra-n-butylammonium fluoride (TBAF) are potential CO2 capture media because they can capture CO2 at near ambient temperature under moderate pressure such as below 1 MPa. In addition to other semiclathrate hydrates, CO2 capture properties of TBAF hydrates may vary with formation conditions such as aqueous composition and pressure because of their complex hydrate structures. In this study, we investigated CO2 capture properties of TBAF hydrates for simulated flue gas, that is, CO2 + N2 gas, by the gas separation test with three different parameters for each pressure and aqueous composition of TBAF in mass fraction (w TBAF). The CO2 capture amount in TBAF hydrates with w TBAF = 0.10 was smaller than that obtained with w TBAF = 0.20 and 0.30. The results found that gas pressure greatly changed the CO2 capture amount in TBAF hydrates, and the aqueous composition highly affected CO2 selectivity. The crystal morphology and single-crystal structure analyses suggested that polymorphism of TBAF hydrates with congruent aqueous solution may lower both the CO2 capture amount and selectivity. Our present results proposed that an aqueous solution with w TBAF = 0.20 is advantageous for the CO2 capture from flue gas compared to near congruent solutions of TBAF hydrates (w TBAF = 0.30) and dilute solution (w TBAF = 0.10).

Adventitial matrix metalloproteinase production and distribution of immunoglobulin G4-related abdominal aortic aneurysms.

OBJECTIVE: IgG4-related diseases are systemic inflammatory fibrous lesions characterized by elevated serum IgG4 and infiltration of IgG4-positive plasmacytes. They can manifest in vascular lesions as frequently formed aneurysms with prominent thickening of the adventitia (IgG4-related abdominal aortic aneurysm; IgG4-AAA). Matrix metalloproteinases (MMPs) degrade the extracellular matrix, mainly in the tunica media, resulting in destruction of aortic structures to cause enlargement of the aneurysm. However, the expression of adventitial MMPs in IgG4-AAAs is poorly understood. METHODS: MMPs and MMPs-presenting cells in the adventitia of IgG4-AAAs (n = 19) of human surgical specimens were evaluated by immunohistochemistry and dual messenger RNA in situ hybridization. The results were compared with those from control groups of non-IgG4-related inflammatory AAA (n = 18), atherosclerotic AAA (aAAA; n = 11), and autopsy cases (n = 11). Preoperative serum MMPs levels of these groups were compared with the histologic data. RESULTS: Expression of MMP-9, MMP-2, and MMP-14 at the protein and messenger RNA levels in the adventitia was significantly higher in IgG4-AAAs than in controls. Other MMPs were scarce. The total number of MMP-9-positive cells was positively correlated with the diameter of the aneurysm (R = 0.461; P = .031), the adventitial thickness (R = 0.688; P < .001), and the number of IgG4-positive cells (R = 0.764; P < .001). Within lymphoid follicles, MMP-9-presenting cells were predominantly detected in large follicular dendritic cells, followed by histiocytes, fibroblasts, and plasmacytic dendritic cells. Outside lymphoid follicles, fibroblasts, and histiocytes mainly expressed MMP-9, and tissue dendritic cells also produced MMP-9. The levels of MMP-9 derived from follicular dendritic cells and histiocytes and plasmacytic dendritic cells outside lymphoid follicles were significantly higher in IgG4-AAA group than in other groups. Expression of adventitial MMP-2 and MMP-14 by histiocytes and fibroblasts was predominantly detected outside lymphoid follicles. Serum MMP-9 levels were significantly higher in IgG4-AAAs (835 ng/mL) than in controls, and correlated with serum IgG4 levels and the total numbers of adventitial MMP-9-positive cells, whereas serum MMP-2 levels did not differ among the three aneurysmal groups. CONCLUSIONS: MMP-9 production in adventitial immune cells concerning lymphoid follicles was characteristic of IgG4-AAAs and might work in its activity with aneurysmal dilatation and adventitial thickening. Expressions of adventitial MMP-2 and MMP-14 were detected in histiocytes and fibroblasts outside lymphoid follicles, and were less concerned with the activity of IgG4-AAAs.

Structural evolution of methane hydrate under pressures up to 134 GPa.

High-pressure experiments were performed to understand the structural evolution of methane hydrate (MH) up to 134 GPa using x-ray powder diffraction (XRD) and Raman spectroscopy with diamond anvil cells. XRD revealed the distinct changes in the diffraction lines of MH owing to phase transition from a guest-ordered state phase [MH-III(GOS)] to a new high-pressure phase (MH-IV) at 33.8-57.7 GPa. MH-IV was found to be stable up to at least 134 GPa without decomposition into solid methane and high-pressure ices. Raman spectroscopy showed the splits in the C-H vibration modes ν3 and ν1 of guest methane molecules in filled-ice Ih (MH-III) at 12.7 GPa and 28.6 GPa, respectively. These splits are caused by orientational ordering of guest methane molecules contained in the hydrate structure, as observed in a previous study. These results suggest that the structural evolution of the filled-ice structure of MH is caused by successive orientational ordering of guest methane molecules, thereby inducing changes in the host framework formed by water molecules.

[Coil Embolization for an Aberrant Left Subclavian Artery Aneurysm with Kommerell's Diverticulum;Report of a Case].

A 67-year-old woman encountered a traffic accident and had chest computed tomography(CT) examination. It revealed a 24 mm Kommerell's diverticulum associated with a right-sided aortic arch and a 15 mm saccular aneurysm of an aberrant left subclavian artery. We performed intra-aneurysmal coil embolization for the left subclavian artery aneurysm after a balloon occlusion test of the left subclavian artery. The postoperative course was uneventful.

Aneurysm resection interposed with a spiral saphenous vein graft in a patient with a popliteal venous aneurysm with thrombosis.

We describe the case of a 46-year-old man with pulmonary thromboembolism caused by a popliteal venous aneurysm with thrombosis. The aneurysm was fusiform and partially saccular with a thrombus, and the caliber of the native popliteal vein was large. Tangential aneurysmectomy with lateral venorrhaphy was difficult because of the aneurysm type, and graft interposition was required because of the large venous diameter of the anastomosis site. The patient underwent aneurysm resection interposed with a spiral saphenous vein graft. The postoperative course was uneventful, and the graft was patent at 1 year after surgery.

Kinetic inhibition effect of Type I and III antifreeze proteins on unidirectional tetrahydrofuran hydrate crystal growth.

Experiments were performed to evaluate the kinetic inhibition effect of Type I and Type III antifreeze proteins (AFPs), polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) on the growth of tetrahydrofuran (THF) clathrate hydrate crystals using the unidirectional growth technique. The crystal growth interface shifted under an applied temperature gradient over a given time. Type I AFP was the most effective kinetic inhibitor, followed by PVP, Type III AFP and PVA. The morphology of the THF hydrate was affected significantly by the concentration of Type I AFP. At low concentrations of Type I AFP, a large hexagonal plate-like crystal formed. At high concentrations, the growth interface became relatively flat. Conversely, at low concentrations of Type III AFP, the morphology of the THF hydrate crystal was unaffected by the additive.

Beating aortic valve replacement surgery as an alternative to transcatheter aortic valve implantation in a patient with severe aortic stenosis and left ventricular dysfunction.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is the standard treatment for high-risk patients with aortic stenosis (AS); however, alternative treatments for patients who are ineligible for TAVI are controversial. CASE PRESENTATION: 56 year-old female who required 6 γ dobutamine support due to congestive heart failure was diagnosed as severe aortic stenosis with bicuspid valve. Echocardiography revealed left ventricular ejection fraction (LVEF) was 15%. The patient was relatively young for TAVI, and TAVI was not licensed for patient presenting with a bicuspid aortic valve in places other than the limited institutions in Japan. On pump beating aortic valve replacement (AVR) was performed with selective antegrade coronary artery blood perfusion. She resumed a completely normal lifestyle by 3 weeks after the operation. CONCLUSIONS: A relatively young patient for TAVI who was diagnosed as aortic stenosis with severely reduced ejection fraction and bicuspid valve is reported. Beating AVR with a continuously selective antegrade-perfusion was achieved safely with good clinical results in a patient with severely reduced left ventricular (LV) function. Beating AVR can be considered as a potential alternative for patients who are ineligible for conventional surgical aortic valve replacement (SAVR) and TAVI.