[A Huge Aortic Root Aneurysm Nineteen Years After Aortic Valve Replacement:Report of a Case].

We report a case of huge aortic root aneurysm 19 years after aortic valve replacement. A 58-year-old woman was referred to us for aortic root dilatation. She underwent aortic valve replacement with mechanical valve due to severe aortic regurgitation of tricuspid aortic valve 19 years ago. We performed graft replacement of aortic root preserving prior mechanical prosthetic valve. Histological examination of aneurysm showed myxomatous change in medial layer. Aortic root dilatation after aortic valve replacement is caused by bicuspid valve, aortic dissection, Marfan syndrome, tissue disorder disease, aortitis, and dilated Valsalva sinus at the time of prior operation. It is important to follow-up a patient for root dilatation after aortic valve replacement.

Adipose-derived stem cell sheet under an elastic patch improves cardiac function in rats after myocardial infarction.

OBJECTIVES: Although adipose-derived stem cells (ADSCs) have shown promise in cardiac regeneration, stable engraftment is still challenging. Acellular bioengineered cardiac patches have shown promise in positively altering ventricular remodeling in ischemic cardiomyopathy. We hypothesized that combining an ADSC sheet approach with a bioengineered patch would enhance ADSC engraftment and positively promote cardiac function compared with either therapy alone in a rat ischemic cardiomyopathy model. METHODS: Cardiac patches were generated from poly(ester carbonate urethane) urea and porcine decellularized cardiac extracellular matrix. ADSCs constitutively expressing green fluorescent protein were established from F344 rats and transplanted as a cell sheet over the left ventricle 3 days after left anterior descending artery ligation with or without an overlying cardiac patch. Cardiac function was serially evaluated using echocardiography for 8 weeks, comparing groups with combined cells and patch (group C, n = 9), ADSCs alone (group A, n = 7), patch alone (group P, n = 6) or sham groups (n = 7). RESULTS: Much greater numbers of ADSCs survived in the C versus A groups (P < .01). At 8 weeks posttransplant, the percentage fibrotic area was lower (P < .01) in groups C and P compared with the other groups and vasculature in the peri-infarct zone was greater in group C versus other groups (P < .01), and hepatocyte growth factor expression was higher in group C than in other groups (P < .05). Left ventricular ejection fraction was higher in group C versus other groups. CONCLUSIONS: A biodegradable cardiac patch enhanced ADSC engraftment, which was associated with greater cardiac function and neovascularization in the peri-infarct zone following subacute myocardial infarction.

[Mitral Valve Infective Endocarditis Complicated with Meningitis in a Patient with Atopic Dermatitis;Report of a Case].

Meningitis has not been described to the same extent as other neurological complications of infective endocarditis(IE). The appropriate selection and dosing of antibiotics for patients with IE and meningitis do not exist. Herein, we described an instructive surgical case of mitral valve endocarditis and meningitis caused in a patient with atopic dermatitis, that was successfully treated using a multi-disciplinary approach.

Acute In Vivo Functional Assessment of a Biodegradable Stentless Elastomeric Tricuspid Valve.

Degradable heart valves based on in situ tissue regeneration have been proposed as potentially durable and non-thrombogenic prosthetic alternatives. We evaluated the acute in vivo function, microstructure, mechanics, and thromboresistance of a stentless biodegradable tissue-engineered heart valve (TEHV) in the tricuspid position. Biomimetic stentless tricuspid valves were fabricated with poly(carbonate urethane)urea (PCUU) by double-component deposition (DCD) processing to mimic native valve mechanics and geometry. Five swine then underwent 24-h TEHV implantation in the tricuspid position. Echocardiography demonstrated good leaflet motion and no prolapse and trace to mild regurgitation in all but one animal. Histology revealed patches of proteinaceous deposits with no cellular uptake. SEM demonstrated retained scaffold microarchitecture with proteinaceous deposits but no platelet aggregation or thrombosis. Explanted PCUU leaflet thickness and mechanical anisotropy were comparable with native tricuspid leaflets. Bioinspired, elastomeric, stentless TEHVs fabricated by DCD were readily implantable and demonstrated good acute function in the tricuspid position.

Spinal cord injury following aortic arch replacement.

PURPOSE: Postoperative spinal cord injury is a devastating complication after aortic arch replacement. The purpose of this study was to determine the predictors of this complication. METHODS: A group of 254 consecutive patients undergoing aortic arch replacement via median sternotomy, with (n = 78) or without (n = 176) extended replacement of the upper descending aorta, were included in a risk analysis. The frozen elephant trunk technique was used in 46 patients. The patients' atherothrombotic lesions (extensive intimal thickening of > 4 mm) were identified from computed tomography images. RESULTS: Complete paraplegia (n = 7) and incomplete paraparesis (n = 4) occurred immediately after the operation (permanent spinal cord injury rate, 1.97%; transient spinal cord injury rate, 2.36%). A multivariable logistic regression analysis identified the use of the frozen elephant trunk technique (odds ratio 36.3), previous repair of thoracoabdominal aorta or descending aorta (odds ratio 29.4), proximal atherothrombotic aorta (odds ratio 9.6), chronic obstructive lung disease (odds ratio 7.1) and old age (odds ratio 1.1) as predictors of spinal cord injury (p < 0.0001, area under curve 0.93). CONCLUSIONS: Spinal cord injury occurs with a non-negligible incidence following aortic arch replacement. The full objective assessment of the morphology of the whole aorta and the recognition of the risk factors are mandatory.

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.

In vivo functional assessment of a novel degradable metal and elastomeric scaffold-based tissue engineered heart valve.

OBJECTIVE: Ideal heart valve solutions aim to provide thrombosis-free durability. A scaffold-based polycarbonate urethane urea tissue-engineered heart valve designed to mimic native valve microstructure and function was used. This study examined the acute in vivo function of a stented tissue-engineered heart valve in a porcine model. METHODS: Trileaflet valves were fabricated by electrospinning polycarbonate urethane urea using double component fiber deposition. The tissue-engineered heart valve was mounted on an AZ31 magnesium alloy biodegradable stent frame. Five 80-kg Yorkshire pigs underwent open tissue-engineered heart valve implantation on cardiopulmonary bypass in the pulmonary position. Tissue-engineered heart valve function was echocardiographically evaluated immediately postimplant and at planned study end points at 1, 4, 8, and 12 hours. Explanted valves underwent biaxial mechanical testing and scanning electron microscopy for ultrastructural analysis and thrombosis detection. RESULTS: All 5 animals underwent successful valve implantation. All were weaned from cardiopulmonary bypass, closed, and recovered until harvest study end point except 1 animal that was found to have congenital tricuspid valve dysplasia and that was euthanized postimplant. All 5 cases revealed postcardiopulmonary bypass normal leaflet function, no regurgitation, and an average peak velocity of 2 m/s, unchanged at end point. All tissue-engineered heart valve leaflets retained microstructural architecture with no platelet activation or thrombosis by scanning electron microscopy. There was microscopic evidence of fibrin deposition on 2 of 5 stent frames, not on the tissue-engineered heart valve. Biaxial stress examination revealed retained postimplant mechanics of tissue-engineered heart valve fibers without functional or ultrastructural degradation. CONCLUSIONS: A biodegradable elastomeric heart valve scaffold for in situ tissue-engineered leaflet replacement is acutely functional and devoid of leaflet microthrombosis.

Reactive oxygen species scavenging with a biodegradable, thermally responsive hydrogel compatible with soft tissue injection.

Tissue damage and the impairment of regenerative processes by excessive reactive oxygen species (ROS) contributes to the pathogenesis of various diseases in soft tissues including diabetes, atherosclerosis, Parkinson's disease and myocardial ischemic/reperfusion injury. In this study, a thermally responsive injectable hydrogel poly(NIPAAm-co-VP-co-MAPLA-co-MATEMPO) (pNVMT, NIPAAm: N-isopropylacrylamide, VP: vinylpyrrolidone, MAPLA: methacrylate-polylactide, MATEMPO: methacrylate-TEMPO, TEMPO: 4-amino-TEMPO or 4-Amino-2,2,6,6-tetramethylpiperidine-1-oxyl) incorporating recyclable ROS scavenging nitroxide radicals on the polymer backbone was developed to locally control adverse tissue effects from free radical generation. In an in vitro oxidative environment, TEMPO Gel significantly preserved cell viability. In a rat myocardial infarction/reperfusion model, TEMPO Gel diffused through the infarcted myocardium, integrated with the tissue upon gelation, and remained for over one week as visualized by MRI. The TEMPO Gel reduced infarction/reperfusion injury and preserved left ventricle geometry. This thermally responsive hydrogel was demonstrated to have properties desirable for local application to soft tissue beds where oxidative damage by ROS is of concern in pathological mechanisms.

Injectable, porous, biohybrid hydrogels incorporating decellularized tissue components for soft tissue applications.

Biodegradable injectable hydrogels have been extensively studied and evaluated in various medical applications such as for bulking agents, drug delivery reservoirs, temporary barriers, adhesives, and cell delivery matrices. Where injectable hydrogels are intended to facilitate a healing response, it may be desirable to encourage rapid cellular infiltration into the hydrogel volume from the tissue surrounding the injection site. In this study, we developed a platform technique to rapidly form pores in a thermally responsive injectable hydrogel, poly(NIPAAm-co-VP-co-MAPLA) by using mannitol particles as porogens. In a rat hindlimb muscle injection model, hydrogels incorporating porosity had significantly accelerated cellular infiltration. To influence the inflammatory response to the injected hydrogel, enzymatically digested urinary bladder matrix (UBM) was mixed with the solubilized hydrogel. The presence of UBM was associated with greater polarization of the recruited macrophage population to the M2 phenotype, indicating a more constructive foreign body response. The hybrid hydrogel positively affected the wound healing outcomes of defects in rabbit adipose tissue with negligible inflammation and fibrosis, whereas scar formation and chronic inflammation were observed with autotransplantation and in saline injected groups. These results demonstrate the value of combining the effects of promoting cell infiltration and mediating the foreign body response for improved biomaterials options soft tissue defect filling applications. STATEMENT OF SIGNIFICANCE: Our objective was to develop a fabrication process to create porous injectable hydrogels incorporating decellularized tissue digest material. This new hydrogel material was expected to exhibit faster cellular infiltration and a greater extent of pro-M2 macrophage polarization compared to control groups not incorporating each of the functional components. Poly(NIPAAm-co-VP-co-MAPLA) was chosen as the representative thermoresponsive hydrogel, and mannitol particles and digested urinary bladder matrix (UBM) were selected as the porogen and the bioactive decellularized material components respectively. In rat hindlimb intramuscular injection models, this new hydrogel material induced more rapid cellular infiltration and a greater extent of M2 macrophage polarization compared to control groups not incorporating all of the functional components. The hybrid hydrogel positively affected the wound healing outcomes of defects in rabbit adipose tissue with negligible inflammation and fibrosis, whereas scar formation and chronic inflammation were observed with autotransplantation and in saline injected groups. The methodology of this report provides a straightforward and convenient mechanism to promote cell infiltration and mediate foreign body response in injectable hydrogels for soft tissue applications. We believe that the readership of Acta Biomaterialia will find the work of interest both for its specific results and general translatability of the findings.

Sustained viral gene delivery from a micro-fibrous, elastomeric cardiac patch to the ischemic rat heart.

Biodegradable and elastomeric patches have been applied to the surface of infarcted hearts as temporary mechanical supports to effectively alter adverse left ventricular remodeling processes. In this report, recombinant adeno-associated virus (AAV), known for its persistent transgene expression and low pathogenicity, was incorporated into elastomeric polyester urethane urea (PEUU) and polyester ether urethane urea (PEEUU) and processed by electrospinning into two formats (solid fibers and core-sheath fibers) designed to influence the controlled release behavior. The extended release of AAV encoding green fluorescent protein (GFP) was assessed in vitro. Sustained and localized viral particle delivery was achieved over 2 months in vitro. The biodegradable cardiac patches with or without AAV-GFP were implanted over rat left ventricular lesions three days following myocardial infarction to evaluate the transduction effect of released viral vectors. AAV particles were directly injected into the infarcted hearts as a control. Cardiac function and remodeling were significantly improved for 12 weeks after patch implantation compared to AAV injection. More GFP genes was expressed in the AAV patch group than AAV injection group, with both α-SMA positive cells and cardiac troponin T positive cells transduced in the patch group. Overall, the extended release behavior, prolonged transgene expression, and elastomeric mechanical properties make the AAV-loaded scaffold an attractive option for cardiac tissue engineering where both gene delivery and appropriate mechanical support are desired.

Ventricular wall biomaterial injection therapy after myocardial infarction: Advances in material design, mechanistic insight and early clinical experiences.

Intramyocardial biomaterial injection therapy for myocardial infarction has made significant progress since concept initiation more than 10 years ago. The interim successes and progress in the first 5 years have been extensively reviewed. During the last 5 years, two phase II clinical trials have reported their long term follow up results and many additional biomaterial candidates have reached preclinical and clinical testing. Also in recent years deeper investigations into the mechanisms behind the beneficial effects associated with biomaterial injection therapy have been pursued, and a variety of process and material parameters have been evaluated for their impact on therapeutic outcomes. This review explores the advances made in this biomaterial-centered approach to ischemic cardiomyopathy and discusses potential future research directions as this therapy seeks to positively impact patients suffering from one of the world's most common sources of mortality.

Solitary fibrous tumor causing cardiac tamponade.

Solitary fibrous tumor of the pleura is a rare primary tumor arising from mesenchymal cells in the areolar tissue subjacent to the mesothelial-lined pleura. Most solitary fibrous tumor of the pleura arises from the visceral or the parietal pleura, and asymptomatically occupies the hemithoracic cavity. We report a rare case of solitary fibrous tumor of the pleura causing cardiac tamponade. A 30-year-old woman presented with pericardial tumor. The surgical resection of the tumor was complete. We describe the details of this case and a brief review of the literature about solitary fibrous tumor.

[Traumatic aortic injury].

Optimal timing of surgical repair for traumatic aortic injury (TAI) is still controversial. We have experienced 3 cases of TAI. The 1st one suffered from severe multisystem trauma in addition to TAI, so we performed graft replacement of the proximal descending aorta electively 31 days after the injury. The 2nd one had massive pleural effusion on admission and we performed urgent operation. They recovered uneventfully. The last one died of aortic re-rupture during anesthetic induction despite attempting emergent operation. In patients with serious multisystem trauma besides TAI, surgical repair can be delayed as long as there are no signs of on-going rupture and/or bleeding, however close observation, serial computed tomography( CT) check-ups and strict control of blood pressure are needed.

Composite vein graft reconstruction for infected descending aortic prosthesis.

We report a case of successful in situ replacement with a superficial femoropopliteal vein panel graft for Dacron graft infection of the thoracic aorta. A 75-year-old man presented with septicemia and pseudoaneurysm caused by methicillin resistant staphylococcus aureus 2 years after Dacron graft replacement of the mid-descending aortic aneurysm. The patient underwent in situ replacement with a panel graft constructed of 3 deep vein panels after excision of the infected Dacron graft. The patient is free of infection and doing well over 2 years after surgery.

Malignant fibrous histiocytoma originating from right ventricular outflow tract.

A 70-year-old man presented with right heart failure due to obstruction of the right ventricular outflow tract by a large tumor mass. The tumor was surgically resected as much as possible. Neither chemotherapy nor radiotherapy was given. The patient died of local recurrence and multiple lung metastases 6 months after surgery. The prognosis of this very rare primary cardiac tumor is generally poor.

Safety of mild hypothermic circulatory arrest with selective cerebral perfusion.

Although hypothermic circulatory arrest with antegrade selective cerebral perfusion is used for cerebral protection, optimal perfusion characteristics are still unclear. Between May 2006 and March 2008, 26 patients (mean age, 68.9 years; 14 males) underwent thoracic aortic repair with mild hypothermic circulatory arrest (34.3 degrees C +/- 1.9 degrees C) and antegrade selective cerebral perfusion (30 degrees C) for various indications including 16 acute type A aortic dissections. Mean cerebral perfusion rate was 21.1 +/- 4.3mL kg(-1) min(-1). Non-elective operations were carried out in 16 (61.5%) cases. Operative procedures were ascending aortic replacement in 16 patients, hemiarch replacement in 4, and total arch replacement in 6. Cardiopulmonary bypass time was 209 +/- 61 min, cardiac ischemic time was 141 +/- 45 min, cerebral perfusion time was 81 +/- 67 min, and lower body circulatory arrest time was 65 +/- 22 min. Mean rectal temperature drifted to 30.6 degrees C +/- 1.3 degrees C. There was 1 (3.8%) hospital death due to rupture of a residual descending thoracic aneurysm. One patient needed reexploration for bleeding, and 2 (7.7%) suffered permanent neurologic dysfunction. No postoperative spinal cord dysfunction was observed. Mild hypothermic circulatory arrest with antegrade selective cerebral perfusion could be performed safely in our patient population.

Nonmycotic false aneurysm of aortic cannulation site presenting 26 years postoperatively.

We report the case of a 64-year-old woman who presented with a false aneurysm in the ascending aorta where arterial cannulation was done in an operation 26 years earlier. The aneurysm was excised with the ascending aorta and successfully replaced with a prosthetic graft during deep hypothermic circulatory arrest and retrograde cerebral perfusion, accompanied with concomitant procedures of mitral valve replacement and maze procedure. When the aneurysm, 3.5 x 3.0 x 4.5 cm, was removed, it showed a remarkable sharp line of demarcation between the normal aorta. Microscopic examination of the specimen was consistent with the features of a pseudoaneurysm.