Usefulness of bicarbonate-based Impella purge solution in a patient with heparin-induced thrombocytopenia: the first case report of long-term management in Japan.

Percutaneous mechanical circulatory support utilizing micro-axial flow pumps, such as the Impella group of devices, has become a life-saving technique in the treatment of refractory cardiogenic shock, with ever-increasing success rates. A 30-year-old man presented with acute decompensated heart failure and a severely reduced left ventricular ejection fraction (17%). Despite initial treatment with inotropic drugs and intra-aortic balloon pump support, his hemodynamic status remained unstable. Transition to Impella CP mechanical circulatory support was made on day 6 owing to persistently low systolic blood pressure. A significant decline in platelet count prompted suspicion of heparin-induced thrombocytopenia (HIT), later confirmed by positive platelet-activated anti-platelet factor 4/heparin antibody and a 4Ts score of 6 points. Argatroban was initially used as the purge solution, but owing to complications, a switch to Impella 5.0 and a bicarbonate-based purge solution (BBPS) was performed. Despite additional veno-arterial extracorporeal membrane oxygenation support on day 24, the patient, aiming for ventricular assist device treatment and heart transplantation, died from infection and multiple organ failure. Remarkably, the Impella CP continued functioning normally until the patient's demise, indicating stable Impella pump performance using BBPS. This case highlights the usefulness of BBPS as an alternative to conventional Impella heparin purge solution when HIT occurs.

Cardiac Rehabilitation in Severe Heart Failure Patients with Impella 5.0 Support via the Subclavian Artery Approach Prior to Left Ventricular Assist Device Implantation.

Impella 5.0 circulatory support via subclavian artery (SA) access may be a safe approach for patients undergoing cardiac rehabilitation (CR). In this case series, we retrospectively analyzed the demographic characteristics, physical function, and CR data of six patients who underwent Impella 5.0 implantation via the SA prior to left ventricular assist device (LVAD) implantation between October 2013 and June 2021. The median age was 48 years, and one patient was female. Grip strength was maintained or increased in all patients before LVAD implantation (pre-LVAD) compared to after Impella 5.0 implantation. The pre-LVAD knee extension isometric strength (KEIS) was less than 0.46 kgf/kg in two patients and more than 0.46 kgf/kg in three patients (unavailable KEIS data, n = 1). With Impella 5.0 implantation, two patients could ambulate, one could stand, two could sit on the edge of the bed, and one remained in bed. One patient lost consciousness during CR due to decreased Impella flow. There were no other serious adverse events. Impella 5.0 implantation via the SA allows mobilization, including ambulation, prior to LVAD implantation, and CR can be performed relatively safely.

A Surgical Case for Pregnancy-Related Spontaneous Coronary Artery Dissection.

The efficacy of coronary artery bypass grafting for pregnancy-related spontaneous coronary artery dissection (SCAD) is controversial, as graft occlusion due to SCAD lesion healing has been reported. Only 24 grafts in 14 cases of coronary artery bypass grafting for SCAD have been reported: 8 of the 9 arterial grafts were occluded, but 9 of the 15 vein grafts were patent. We encountered a case of coronary artery bypass grafting with left internal thoracic artery to the left antero-descending branch due to pregnancy-related SCAD. The patient's graft revealed good patency immediately postoperatively but string signs 7 months later due to healing of SCAD lesions.

Do meteorological factors influence the occurrence of acute aortic dissection? A 10-year retrospective institutional study.

OBJECTIVE: This study aimed to clarify the relationship between meteorological factors and the occurrence of aortic dissection. METHODS: The study included 282 consecutive patients who were admitted to our institute with acute aortic dissection over a 10-year period. The local meteorological data over the same period were analyzed. RESULTS: On the days with occurrences of acute aortic dissection, there were significant differences in the following factors: the minimum and maximum temperature (p < 0.0001), difference in the minimum and maximum temperature from the 10-year average, atmospheric pressure (p < 0.0001), and difference in atmospheric pressure between the day of occurrence and the previous day. Cut-off values were determined by ROC curve analysis. Univariate analyses identified the following factors as significant predictors of the occurrence of acute aortic dissection: minimum temperature < 4.0 °C (OR 2.42, p < 0.0001), maximum temperature < 15.1 °C (OR 2.23, p < 0.0001), atmospheric pressure > 1008.9 hPa (OR 1.75, p < 0.0001), difference between the minimum temperature and 10-year average < 0.3 °C, difference between the maximum temperature and 10-year average < 0.44 °C; and the difference in atmospheric pressure between the day of occurrence and the previous day > 0.4 hPa. However, the differences of the minimum and maximum temperatures from the 10-year average were the only factors that remained significant in the multivariate analysis. The minimum (R2 = 0.3055) and maximum temperatures (R2 = 0.4151) were weakly and moderately correlated, respectively, with the occurrence of acute aortic dissection. CONCLUSION: Meteorological factors influenced the occurrence of acute aortic dissection. In particular, a minimum temperature of < 4 °C and maximum temperature difference from the 10-year average < 0.44 °C was identified as strong risk factors for the occurrence of acute aortic dissection.

Successful Endovascular Repair of a Ruptured Common Iliac Artery Aneurysm Associated with an Ileal Pouch Neobladder Fistula.

A spontaneous fistula between a ruptured common iliac artery aneurysm and the ileal pouch neobladder is quite rare. We present the case of a 74-year-old man presenting with intense abdominal pain and massive hematuria. Computed tomography angiography revealed a ruptured common iliac artery aneurysm-ileal pouch neobladder fistula. His hemodynamics was unstable; emergent endovascular aortic repair was performed successfully. Infection and dysfunction of the neobladder were avoided owing to appropriate management.

Intramyocardial injection of a fully synthetic hydrogel attenuates left ventricular remodeling post myocardial infarction.

Intramyocardial hydrogel injection is an innovative and promising treatment for myocardial infarction (MI) and has recently entered clinical trials. By providing mechanical support to the ventricular wall, hydrogel injectate may act to preserve cardiac function and slow the remodeling process that leads to heart failure. However, improved outcomes will likely depend on the use of hydrogels specifically designed for this unique application, and better understanding of the mechanisms affected by the intervention. In this work, we present the first large animal study achieving functional and geometrical improvements in treating MI using a relatively stiff, fully synthetic hydrogel designed for intramyocardial injection. In addition, the renin-angiotensin system coincided with the mechanical effects of hydrogel injection and attenuated left ventricular remodeling, even after significant hydrogel degradation had occurred in vivo. These results may inspire further optimization of hydrogel materials used in intramyocardial hydrogel injection therapy and a better description of physiologic pathways affected by its implementation to facilitate successful clinical translation.

Conservative treatment of type A aortic dissection following hybrid arch repair.

OBJECTIVE: Type A aortic dissection (TAAD) following hybrid arch repair (HAR) is a lethal complication. Open surgical repair is the ideal treatment, but this can be difficult, as most candidates have complications and are unsuitable for the conventional open aortic repair. We herein report three cases of TAAD after HAR and assess the treatment options. METHODS: Of 261 aortic arch repair cases between April 2010 and March 2018, 38 underwent HAR using debranching of all the arch vessels followed by stent graft implantation landing proximally in zone 0 (type 1 HAR). Three cases suffered from TAAD, and their background characteristics and post-operative outcomes were studied retrospectively. RESULTS: The three TAAD cases were elderly with a high risk of mortality due to comorbidities. TAAD for Cases 1, 2, and 3 was detected on post-operative day (POD) 11, POD11, and during the procedure, respectively. Case 1 was complicated with both respiratory and renal failures, and Case 3 suffered from severe neurological impairment when TAAD was detected. No additional open aortic repair was performed in any cases. Case 3 died on POD5 due to aortic rupture. Cases 1 and 2 have survived for more than 50 months since their initial surgeries. CONCLUSIONS: TAAD following HAR can be detected with post-operative imaging despite a lack of signs noted during the intra- and post-operative periods. Conservative therapy might, therefore, be an acceptable option for subacute-onset TAAD following HAR with stable hemodynamics, even though such patients do required a very careful follow-up.

Hemodynamics of cardiac tamponade during extracorporeal membrane oxygenation support in a patient with fulminant myocarditis.

Fulminant myocarditis (FM) causes rapid onset severe heart failure requiring inotropes or mechanical circulatory support. Myocarditis is sometimes associated with pericardial effusion, however, how this effusion affects the hemodynamics in patients with FM under venoarterial extracorporeal membrane oxygenation (VA-ECMO) management has not been fully reported. We show a case of FM presenting with cardiac tamponade during VA-ECMO management. A 64-year-old female diagnosed as having FM showed a rapid hemodynamic collapse and that led to the application of VA-ECMO. Although her left ventricular ejection fraction did not improve despite proper hemodynamics management for several days, a pericardial effusion accumulated gradually. Apparent elevation of right atrial pressure and reduction of blood pressure were not observed, however, we performed pericardiocentesis because we were not able to wean off VA-ECMO. After the drainage of pericardial effusion, the blood pressure and cardiac output elevated as did the left ventricular ejection fraction. We successfully removed VA-ECMO and the patient was discharged without any complications. This is a case report in which a cardiac tamponade under VA-ECMO did not show typical signs and pericardiocentesis contributed to withdrawal of a VA-ECMO system. .

Promising method for management of venoarterial extracorporeal membrane oxygenation: A case of severe heart failure successfully stabilized by "high-flow/vasodilation method".

We report the case of a 58-year-old man with dilated cardiomyopathy who was hospitalized because of worsening heart failure. As his symptoms were refractory even with the administration of inotropes, he was given peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) upon transfer to our hospital. On admission, serum creatinine was 2.62 mg/dL and total bilirubin 10.8 mg/dL. The cannulas inserted were 16-Fr for infusion and 21-Fr for drainage. When the blood flow was increased to 2.14 L/min/m2 to improve organ dysfunction, the aortic valve became continuously close with the mean arterial pressure of 85 mmHg. Therefore, we administrated vasodilators to decrease mean arterial pressure, or left ventricular afterload, which achieved opening aortic valve continuously. After the cannula sizes were scaled up to 18Fr for infusion and 24Fr for drainage to gain further blood flow, the aortic valve opened continuously and mean pulmonary pressure decreased. Our strategy to maintain adequate flow rate of VA-ECMO using vasodilator, "high-flow/vasodilation method", achieved hemodynamic stability. Additionally, the concentration of serum creatinine and total bilirubin gradually decreased to within the normal range, although the patient succumbed 58 days after transfer to our hospital. .

Strategy of Cardiovascular Surgery for Patients With Dementia as Evaluated by Mini-Mental State Examination.

BACKGROUND: The strategy for cardiovascular surgery in dementia patients is controversial, so we aimed to investigate whether preoperative dementia and its severity might affect the outcomes of cardiovascular surgery by evaluating with the Mini-Mental State Examination (MMSE). Methods and Results: The study group comprised 490 patients undergoing cardiovascular surgery. Their preoperative cognitive status was evaluated using the MMSE, and analysis was performed to compare the patients with MMSE score <24 (dementia group, n=51) or MMSE score 24-30 (non-dementia group, n=439). Furthermore, the effect of the severity of dementia was analyzed with a cut-off MMSE score of 19/20. Risk factors for surgical outcomes were explored using multivariate logistic regression analysis. Hospital mortality was 11.8% in the dementia group and 2.1% in the non-dementia group (P=0.002). Regarding the postoperative morbidities, the incidence of cerebrovascular disorder (P=0.001), pneumonia (P=0.039), delirium (P=0.004), and infection (P=0.006) was more frequent in dementia group. Among the patients with MMSE <20, hospital mortality was as high as 25%, and the rate of delirium was 58%. Multivariate logistic regression analysis revealed that MMSE score <24 (P=0.003), lower serum albumin (P=0.023) and aortic surgery (P=0.036) were independent risk factors for hospital death. CONCLUSIONS: Preoperative dementia affects the outcomes of cardiovascular surgery with regard to hospital death and delirium. The surgical indication for patients with MMSE <20 might be difficult, but surgery with an appropriate strategy should be considered for patients with MMSE <24.

Skeletal muscle derived stem cells microintegrated into a biodegradable elastomer for reconstruction of the abdominal wall.

A variety of techniques have been applied to generate tissue engineered constructs, where cells are combined with degradable scaffolds followed by a period of in vitro culture or direct implantation. In the current study, a cellularized scaffold was generated by concurrent deposition of electrospun biodegradable elastomer (poly(ester urethane)urea, PEUU) and electrosprayed culture medium + skeletal muscle-derived stem cells (MDSCs) or electrosprayed culture medium alone as a control. MDSCs were obtained from green fluorescent protein (GFP) transgenic rats. The created scaffolds were implanted into allogenic strain-matched rats to replace a full thickness abdominal wall defect. Both control and MDSC-integrated scaffolds showed extensive cellular infiltration at 4 and 8 wk. The number of blood vessels was higher, the area of residual scaffold was lower, number of multinucleated giant cells was lower and area of connective tissue was lower in MDSC-integrated scaffolds (p < 0.05). GFP + cells co-stained positive for VEGF. Bi-axial mechanical properties of the MDSC-microintegrated constructs better approximated the anisotropic behavior of the native abdominal wall. GFP + cells were observed throughout the scaffold at ∼5% of the cell population at 4 and 8 wk. RNA expression at 4 wk showed higher expression of early myogenic marker Pax7, and b-FGF in the MDSC group. Also, higher expression of myogenin and VEGF were seen in the MDSC group at both 4 and 8 wk time points. The paracrine effect of donor cells on host cells likely contributed to the differences found in vivo between the groups. This approach for the rapid creation of highly-cellularized constructs with soft tissue like mechanics offers an attractive methodology to impart cell-derived bioactivity into scaffolds providing mechanical support during the healing process and might find application in a variety of settings.

Bi-layered polyurethane - Extracellular matrix cardiac patch improves ischemic ventricular wall remodeling in a rat model.

As an intervention to abrogate ischemic cardiomyopathy, the concept of applying a temporary, local patch to the surface of the recently infarcted ventricle has been explored from a number of design perspectives. Two important features considered for such a cardiac patch include the provision of appropriate mechanical support and the capacity to influence the remodeling pathway by providing cellular or biomolecule delivery. The objective of this report was to focus on these two features by first evaluating the incorporation of a cardiac extracellular matrix (ECM) component, and second by evaluating the impact of patch anisotropy on the pathological remodeling process initiated by myocardial infarction. The functional outcomes of microfibrous, elastomeric, biodegradable cardiac patches have been evaluated in a rat chronic infarction model. Ten weeks after infarction and 8 wk after patch epicardial placement, echocardiographic function, tissue-level structural remodeling (e.g., biaxial mechanical response and microstructural analysis), and cellular level remodeling were assessed. The results showed that the incorporation of a cardiac ECM altered the progression of several keys aspects of maladaptive remodeling following myocardial infarction. This included decreasing LV global mechanical compliance, inhibiting echocardiographically-measured functional deterioration, mitigating scar formation and LV wall thinning, and promoting angiogenesis. In evaluating the impact of patch anisotropy, no effects from the altered patch mechanics were detected after 8 wk, possibly due to patch fibrous encapsulation. Overall, this study demonstrates the benefit of a cardiac patch design that combines both ventricle mechanical support, through a biodegradable, fibrillary elastomeric component, and the incorporation of ECM-based hydrogel components.

Design of a Coupled Thermoresponsive Hydrogel and Robotic System for Postinfarct Biomaterial Injection Therapy.

BACKGROUND: In preclinical testing, ventricular wall injection of hydrogels has been shown to be effective in modulating ventricular remodeling and preserving cardiac function. For some approaches, early-stage clinical trials are under way. The hydrogel delivery method varies, with minimally invasive approaches being preferred. Endocardial injections carry a risk of hydrogel regurgitation into the circulation, and precise injection patterning is a challenge. An epicardial approach with a thermally gelling hydrogel through the subxiphoid pathway overcomes these disadvantages. METHODS: A relatively stiff, thermally responsive, injectable hydrogel based on N-isopropylacrylamide and N-vinylpyrrolidone (VP gel) was synthesized and characterized. VP gel thermal behavior was tuned to couple with a transepicardial injection robot, incorporating a cooling feature to achieve injectability. Ventricular wall injections of the optimized VP gel have been performed ex vivo and on beating porcine hearts. RESULTS: Thermal transition temperature, viscosity, and gelling time for the VP gel were manipulated by altering N-vinylpyrrolidone content. The target parameters for cooling in the robotic system were chosen by thermal modeling to support smooth, repeated injections on an ex vivo heart. Injections at predefined locations and depth were confirmed in an infarcted porcine model. CONCLUSIONS: A coupled thermoresponsive hydrogel and robotic injection system incorporating a temperature-controlled injectate line was capable of targeted injections and amenable to use with a subxiphoid transepicardial approach for hydrogel injection after myocardial infarction. The confirmation of precise location and depth injections would facilitate a patient-specific planning strategy to optimize injection patterning to maximize the mechanical benefits of hydrogel placement.

Timing effect of intramyocardial hydrogel injection for positively impacting left ventricular remodeling after myocardial infarction.

Intramyocardial injection of various injectable hydrogel materials has shown benefit in positively impacting the course of left ventricular (LV) remodeling after myocardial infarction (MI). However, since LV remodeling is a complex, time dependent process, the most efficacious time of hydrogel injection is not clear. In this study, we injected a relatively stiff, thermoresponsive and bioabsorbable hydrogel in rat hearts at 3 different time points - immediately after MI (IM), 3 d post-MI (3D), and 2 w post-MI (2W), corresponding to the beginnings of the necrotic, fibrotic and chronic remodeling phases. The employed left anterior descending coronary artery ligation model showed expected infarction responses including functional loss, inflammation and fibrosis with distinct time dependent patterns. Changes in LV geometry and contractile function were followed by longitudinal echocardiography for 10 w post-MI. While all injection times positively affected LV function and wall thickness, the 3D group gave better functional outcomes than the other injection times and also exhibited more local vascularization and less inflammatory markers than the earlier injection time. The results indicate an important role for injection timing in the increasingly explored concept of post-MI biomaterial injection therapy and suggest that for hydrogels with mechanical support as primary function, injection at the beginning of the fibrotic phase may provide improved outcomes.

Tailoring the degradation rates of thermally responsive hydrogels designed for soft tissue injection by varying the autocatalytic potential.

The ability to modulate the degradation properties of biomaterials such as thermally responsive hydrogels is desirable when exploring new therapeutic strategies that rely on the temporary presence of a placed scaffold or gel. Here we report a method of manipulating the absorption rate of a poly(N-isopropylacrylamide) ((poly(NIPAAm)) based hydrogel across a wide range (from 1 d to 5 mo) by small alterations in the composition. Relying upon the autocatalytic effect, the degradation of poly(NIPAAm-co-HEMA-co-MAPLA), (HEMA = 2-hydroxyethyl methacrylate; MAPLA = methacrylate-polylactide) was greatly accelerated by adding a fourth monomer methacrylic acid (MAA) at no more than 2 mol% to obtain poly(NIPAAm-co-HEMA-co-MAPLA-co-MAA) (pNHMMj) where j reflects the MAA molar % in the reactant mixture. MAA residue introduction decreased the pH inside the hydrogels and in surrounding buffered solutions. Accelerated degradation positively correlated with MAA content in pNHMMj polymers, putatively by the accelerated cleavage of MAPLA residues to raise the transition temperature of the polymer above body temperature. Physical properties including thermal transition behavior and initial mechanical strength did not vary significantly with MAA content. A rat hindlimb injection model generally reflected the in vitro observation that higher MAA content resulted in more rapid degradation and cellular infiltration. The strategy of tuning the degradation of thermally responsive hydrogels where degradation or solubilization is determined by their polyester components might be applied to other tissue engineering and regenerative medicine applications where designed biomaterial degradation behavior is needed.

Intramyocardial injection of a synthetic hydrogel with delivery of bFGF and IGF1 in a rat model of ischemic cardiomyopathy.

It is increasingly appreciated that the properties of a biomaterial used in intramyocardial injection therapy influence the outcomes of infarcted hearts that are treated. In this report the extended in vivo efficacy of a thermally responsive material that can deliver dual growth factors while providing a slow degradation time and high mechanical stiffness is examined. Copolymers consisting of N-isopropylacrylamide, 2-hydroxyethyl methacrylate, and degradable methacrylate polylactide were synthesized. The release of bioactive basic fibroblast growth factor (bFGF) and insulin-like growth factor 1 (IGF1) from the gel and loaded poly(lactide-co-glycolide) microparticles was assessed. Hydrogel with or without loaded growth factors was injected into 2 week-old infarcts in Lewis rats and animals were followed for 16 weeks. The hydrogel released bioactive bFGF and IGF1 as shown by mitogenic effects on rat smooth muscle cells in vitro. Cardiac function and geometry were improved for 16 weeks after hydrogel injection compared to saline injection. Despite demonstrating that left ventricular levels of bFGF and IGF1 were elevated for two weeks after injection of growth factor loaded gels, both functional and histological assessment showed no added benefit to inclusion of these proteins. This result points to the complexity of designing appropriate materials for this application and suggests that the nature of the material alone, without exogenous growth factors, has a direct ability to influence cardiac remodeling.

A parallel wire robot for epicardial interventions.

This paper describes the design and preliminary testing of a planar parallel wire robot that adheres to the surface of the beating heart and provides a stable platform for minimally invasive epicardial therapies. The device is deployed through a small subxiphoid skin incision and attaches to the heart using suction. This methodology obviates mechanical stabilization and lung deflation, which are typically required during minimally invasive beating-heart surgery. The prototype design involves three vacuum chambers connected by two flexible arms. The chambers adhere to the epicardium, forming the vertices of a triangular base structure. Three cables connect a movable end-effector head to the three bases; the cables then pass out of the body to external actuators. The surgical tool moves within the triangular workspace to perform injections, ablation, or other tasks on the beating heart. Tests in vitro and in vivo were conducted to demonstrate the capabilities of the system. Tests in vivo successfully demonstrated the ability to deploy through a subxiphoid incision, adhere to the surface of the beating heart, move the surgical tool head within the robot's workspace, and perform injections into the myocardium.

Is the mid-term outcome of free right internal thoracic artery with a proximal anastomosis modification inferior to in situ right internal thoracic artery?

BACKGROUND: We investigated the mid-term results of free right internal thoracic artery (RITA) grafts used in an aorto-coronary fashion with a modified proximal anastomosis. METHODS: The subjects were 214 patients who underwent coronary artery bypass grafting with anastomosis to the left circumflex arteries using the RITA as a free graft (Group A: 158 patients) or an in situ graft (Group B: 56 patients). In Group A, the proximal end of the free RITA was anastomosed onto the ascending aorta interposing free graft tissue or to part of its own tissue as a cuff. RESULTS: The number of RITA anastomoses was 1.38 ± 0.50 in Group A and 1.04 ± 0.19 in Group B (P < 0.001). The relationship between perioperative variables and mid-term outcomes was assessed using Cox proportional hazard models. Survival was not associated with the way the RITA graft was performed (Hazard Ratio 5.26, 95 % CI 0.52-53.1, P = 0.159), however, the number of cardiac events was decreased in Group A (Hazard Ratio 2.55, 95 % CI 1.03-6.33, P = 0.043). The graft patency was evaluated in 187 of 214 patients, and at 1, 3 and 5 years was 97.0, 97.0 and 97.0 % in Group A, and 97.9, 92.5 and 80.5 % in Group B (P = 0.378), respectively. CONCLUSION: By modifying the proximal anastomosis of the free RITA, cardiac events may be decreased, while survival and graft patency comparable with in situ RITA can be obtained, and a significantly larger number of targets can be revascularized.

Reconstruction of nonconfluent pulmonary artery using the retroaortic innominate vein for a single ventricle.

The innominate vein usually courses anterior to the aortic arch, where it joins the right brachiocephalic vein to form the superior caval vein. A retroaortic innominate vein is an uncommon finding in patients with congenital heart disease. We report a patient with a single ventricle, single atrium, pulmonary atresia, nonconfluent pulmonary artery, persistent left superior caval vein, absent inferior caval vein (azygos connection), right aortic arch, and retroaortic innominate vein. His innominate vein took an anomalous course. The right brachiocephalic vein crossed from right to left underneath the aortic arch and formed a left superior caval vein with the left brachiocephalic vein and the azygos vein. We reconstructed the nonconfluent pulmonary artery using the retroaortic innominate vein and then performed a total cavopulmonary shunt when he was 32 months of age. Thereafter, a total cavopulmonary connection was carried out at age 42 months.