Thoracic endovascular aortic repair of an ascending aortic pseudoaneurysm.

A 74-year-old man with a history of two thoracic aortic repairs, including a modified Bentall procedure using a mechanical valve and total arch replacement, was referred to our hospital with the development of hoarseness. Computed tomography revealed an anastomotic pseudoaneurysm between the prosthetic grafts in the ascending aorta. Two aortic cuffs for abdominal aorta were deployed through the left axillary artery using a transcatheter aortic valve replacement guidewire placed at the supra-aortic mechanical valve during ventricular rapid pacing and were successfully covered with an inlet to the pseudoaneurysm on postoperative computed tomography. The postoperative course was favorable.

Novel technique in frozen elephant trunk positioning method using the ostium of the coronary artery on transesophageal echocardiography as an index.

The frozen elephant trunk (FET) technique is useful in the single-stage treatment of aortic arch aneurysms. Since there is no established implantation method for evaluating the distal end of the FET during surgery, we propose the FET positioning method using the ostium of the coronary artery on transesophageal echocardiography (TEE) as an index. We performed 11 total arch replacement operations using an FET for aortic arch aneurysm. The planned position of the FET was determined by computed tomography (CT), and the distance to the ostium of the coronary artery was measured. Intraoperatively, using TEE as a guide, the FET was implanted using our method. Postoperative CT was evaluated the distance from the planned FET position, and the average and median difference was only 0.96 cm and 0.6 cm, respectively. TEE-guided FET deployment using the coronary artery ostium as an index is a simple and reproducible technique.

[Successful Use of Left Ventricular Support Device (Impella 5.0) for Ischemic Heart Disease with Cardiogenic Shock:Report of a Case].

Postoperative hemodynamic support with an Impella 5.0 was effective in an obese man who underwent coronary artery bypass grafting (CABG) for ischemic heart disease and cardiogenic shock. A 43-year-old obese man presented to our hospital complaining severe chest pain. Coronary angiography revealed acute coronary syndrome due to severe triple-vessel disease, and the patient fell into a state of shock, which required veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support. The patient subsequently underwent CABG, but he was unable to be separated from VA-ECMO. Impella 5.0 was introduced through right axillary artery on the next day. VA-ECMO was converted to veno-venous (VV)-ECMO on the 3rd postoperative day to enable respiratory rehabilitation in a sitting posi-tion;his respiratory status gradually improved. VV-ECMO and the Impella 5.0 were discontinued on the 6th and 7th postoperative days, respectively. He was eventually transferred to nearby facility for further rehabilitation three months later. As of two years, his cardiac function has improved and he is doing well at home.

[Isolated Pulmonary Valve Endocarditis Accompanying Multiple Pulmonary Embolisms:Report of a Case].

Isolated pulmonary valve infective endocarditis is rare and accounts for only 1.5% to 2.0% of all cases of infective endocarditis. We present a case of isolated pulmonary valve endocarditis, which was successfully treated by pulmonary valve replacement. A 69-year-old man presented with fever and was diagnosed with active pulmonary valve infective endocarditis. He had no apparent predisposing factors. Blood cultures were positive for Streptococcus viridans, and transesophageal echocardiography showed mobile vegetation. His condition improved transiently with intravenous antibiotic therapy;however, high fever and reduced oxygen saturation recurred. Computed tomography showed multiple infiltrative shadows suggesting septic pulmonary embolisms. Urgent surgery was indicated because antibiotic treatment was ineffective. During the operation, we found that vegetation had destroyed all pulmonary leaflets. We performed pulmonary valve replacement with a stented bioprosthetic valve as well as enlargement of the right ventricular outflow tract with a bovine pericardial patch. The postoperative course was uneventful. Antibiotic therapy was continued for six weeks after surgery. For two years since surgery, the patient has experienced no recurrence of infection.

Acute Swine Model for Assessing Biocompatibility of Biomedical Interface Materials.

We established an acute animal model for early, straightforward, and reproducible assessment of a biocompatible material interface. Bilateral femoral artery-to-vein shunts were created in 12 pigs: two tubes per shunt, the left two coated and the right two uncoated. We evaluated two groups: uncontrolled flow (UF; shunt flow unregulated) and controlled flow (CF; shunt flow ∼50 mL/min). For each case on each side, two shunts were evaluated: one for 1 h and the other for 3 h. Arterial blood gas and complete blood count were recorded at baseline, 1, and 3 h. Mean shunt flows were 532 ± 88 mL/min UF and 52 ± 8 mL/min CF. Differences in flow were much smaller in CF (0.5 mL/min; 1% of mean flow) than UF (24.8 mL/min; 5% of mean flow). In UF, significant changes occurred: in pH, from start of shunting through 1 h; in pO2 and pCO2, from start through 3 h. This swine model using bilateral femoral shunts with controlled blood flow provides a reliable, reproducible, easily implemented method by which to evaluate biocompatibility of device coatings at an early stage of investigation.

Ascending aortic replacement for acute type A aortic dissection in octogenarians.

OBJECTIVE: The management of acute type A aortic dissection in elderly patients is controversial. This study aimed to investigate the validity of ascending aortic replacement for acute type A aortic dissection in octogenarians compared with younger patients. METHODS: Twenty-five octogenarians, among 117 consecutive patients with acute type A aortic dissection between January 2000 and October 2013 who underwent emergency surgery, were reviewed retrospectively. The median age was 84 years (80-91 years). The patients were six men and 19 women. All 25 patients underwent ascending aortic replacement under deep hypothermic circulatory arrest. In the same period, 55 patients younger than 80 years with acute type A aortic dissection had ascending aortic replacement performed. Clinical data were prospectively entered into our institutional database. Late follow-up was 6.8 ± 2.8 years and was 100% complete. RESULTS: The 30-day mortality rate was 8% (2/25 patients), which was similar to that in patients younger than 80 years (5%). There were no reoperations in octogenarians and five reoperations in younger patients in the follow-up period. Survival at 1 and 5 years was 80.0 and 59.7% in octogenarians and 90.6 and 81.9% in younger patients, respectively (P = 0.036). CONCLUSION: Ascending aortic replacement for octogenarians with acute type A aortic dissection was successfully performed, resulting in satisfactory early and midterm survival. Aggressive surgical treatment is mandatory for improving the outcome in octogenarians with acute type A aortic dissection.

[Cardiac Amyloidosis Diagnosed Following Mitral Valve Repair; Report of a Case].

We present a case of a 60-year-old female who underwent elective mitral valve repair for mitral valve regurgitation. Intra-aortic balloon pumping was necessary to wean her from cardiopulmonary bypass, and a sudden cardiac arrest happened on postoperative day 17. Due to such unexpected postoperative course, a right ventricular biopsy was done, and she was diagnosed with light chain amyloidosis (AL) type cardiac amyloidosis. Despite long percutaneous cardiopulmonary bypass support, she never recovered from severe heart failure. Cardiac surgeons should be aware of this fatal disease, and preoperative screening with various tests is required.

Impact of transapical aortic cannulation for acute type A aortic dissection.

OBJECTIVE: Early and mid-term result of transapical aortic (TAA) cannulation technique was evaluated compared with femoral artery (FA) cannulation in Acute Type A Aortic Dissection(AAAD). METHODS: From January 2000 to October 2013, 80 consecutive patients with AAAD were underwent the ascending aortic replacement at Nagasaki Kouseikai Hospital. These patients were divided into two groups according to the cannulation site, FA cannulation (n = 34) and TAA cannulation (n = 46). Early and mid-term outcomes were compared between two groups. RESULT: Preoperative patient characteristics were almost comparable between groups. The time from skin incision to starting cardiopulmonary bypass (CPB) was significantly shorter in the TAA group (45 ± 16 vs 23 ± 5.1 min; P <0.001). There were no significant differences in post-operative cerebral infarction in two groups (17% versus 11%; P = NS). The operative mortality rate was 8.8% in FA group and 4.3% in TAA group (P = NS). During follow up (mean, 6.8 years), survival at 3 years and 5 years was 77.4% and 71.9% in TAA group and 76.3% and 73.8% in FA group, respectively. CONCLUSION: The postoperative morbidity and mortality between the two groups were almost the same. TAA cannulation for acute Type A aortic dissection is faster, easy and safe with acceptable early and mid-term outcome.

[Surgical therapy for coronary artery stenosis with coronary artery aneurysm in the left main trunk due to Kawasaki disease; report of a case].

A 56-year-old woman was admitted for ST depression in V4 to V6 in electrocardiogram. Coronary angiography showed a coronary artery aneurysm with severe calcification on the bifurcation of the left main trunk and 99% stenosis in the left anterior descending artery. She did not have a history of Kawasaki disease in her childhood. She did not have any risk factors for ischemic heart disease, either. These findings suggested that the coronary artery lesions were related to Kawasaki disease. Percutaneous coronary intervention was impossible due to the location of the aneurysm which was on the bifurcation of the left main trunk. Single vessel coronary artery bypass grafting was performed for the stenosis in the left anterior descending artery. After the surgery, she was put on warfarin for the prevention of thrombus formation in the aneurysm. We report a rare case of coronary artery aneurysm due to Kawasaki disease.

Short-term in vivo performance of the Cleveland clinic PediPump left ventricular assist device.

The PediPump was implanted in six healthy lambs (mean 25.6 ± 1.4 kg) between the left ventricular apex and the descending aorta to evaluate in vivo performance for up to 30 days. Anticoagulation was achieved by continuous heparin infusion. Three animals were euthanized prematurely, two because of respiratory dysfunction and one because of deteriorating pump performance resulting from thrombus formation inside the pump. Three lambs were electively sacrificed 30 days after implantation; all had stable hemodynamics and minimal hemolysis, as indicated by low plasma free hemoglobin (2.5 ± 3.1 mg/dL). Mean 30-day pump flow was 1.8 ± 0.1 L/min at a pump speed of 12 200 ± 400 rpm. Neither activated clotting time nor activated partial thromboplastin time followed the changes in heparin dose. At necropsy, depositions were observed at the front (n = 1) and rear rotor axial positioning stops (n = 4); improved polishing techniques on the stationary stop surfaces and the addition of a hard-carbon, thin-film coating on the rotating stop of the pumps used for the last two experiments addressed the deposition seen earlier. In conclusion, the PediPump showed excellent hydraulic performance and minimal hemolysis during support for up to 30 days. Depositions observed at the axial positioning stops in earlier experiments were addressed by design and material refinements. We continue to focus on developing effective anticoagulation management in the lamb model as well as on further evaluating and demonstrating pump biocompatibility.

Periarteritis in lung from a continuous-flow right ventricular assist device: role of the local Renin-Angiotensin system.

BACKGROUND: We previously reported renal arterial periarteritis after implantation of a continuous-flow left ventricular assist device in calves. The purpose of the present study was to investigate whether the same periarteritis changes occur in the intrapulmonary arteries after implantation of a continuous-flow right ventricular assist device (CFRVAD) in calves and to determine the mechanism of those histologic changes. METHODS: Ten calves were implanted with a CFRVAD for 29 ± 7 days, and we compared pulmonary artery samples and hemodynamic data before and after CFRVAD implantation prospectively. RESULTS: After implantation, the pulsatility index (pulmonary arterial pulse pressure/pulmonary arterial mean pressure) significantly decreased (0.88 ± 0.40 before vs 0.51 ± 0.22 after; p < 0.05), with severe periarteritis of the intrapulmonary arteries in all animals. Periarterial pathology included hyperplasia and inflammatory cell infiltration. The number of inflammatory cells positive for the angiotensin II type 1 receptor was significantly higher after implantation (7.8 ± 6.5 pre-CFRVAD vs 313.2 ± 145.2 at autopsy; p < 0.01). Serum angiotensin-converting enzyme activity significantly decreased after implantation from 100% to 49.7 ± 17.7% at week 1 (p = 0.01). Tissue levels of angiotensin-converting enzyme also demonstrated a significant reduction (0.381 ± 0.232 before implantation vs 0.123 ± 0.096 at autopsy; p = 0.043). CONCLUSIONS: Periarteritis occurred in the intrapulmonary arteries of calves after CFRVAD implantation. The local renin-angiotensin system (not the angiotensin-converting enzyme pathway) plays an important role in such changes.

Left atrial appendage occlusion: pilot study of a fourth-generation, minimally invasive device.

OBJECTIVE: Exclusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The aim of this study was to evaluate the feasibility and efficacy of a fourth-generation atrial exclusion device developed for minimally invasive applications. METHODS: The novel atrial exclusion device consists of two polymer beams and two elastomeric bands that connect the two beams at either end. Fifteen mongrel dogs were implanted with the device at the base of the left atrial appendage through a median sternotomy and were evaluated at 30 (n = 7), 90 (n = 6), and 180 (n = 2) days after implantation by epicardial echocardiography, left atrial and coronary angiography, gross pathology, and histology. RESULTS: Left atrial appendage exclusion was completed without hemodynamic instability. Coronary angiography revealed that the left circumflex artery was patent in all cases. A new endothelial tissue layer developed, as expected, on the occluded orifice of the left atrium. CONCLUSIONS: This novel atrial exclusion device achieved easy, reliable, and safe exclusion of the left atrial appendage, with favorable histological results in a canine model for up to 6 months. Clinical application could provide a new therapeutic option for reducing the risk of stroke in patients with atrial fibrillation.

Superior chest drainage with an active tube clearance system: evaluation of a downsized chest tube.

PURPOSE: We developed a small-diameter (20-French [Fr]) chest drainage system that incorporates an active tube clearance (ATC) system, and we evaluated its efficacy in an acute hemothorax model. DESCRIPTION: The ATC system includes an internal guidewire that can be advanced into the lumen of the chest tube to keep the tube from clogging. In six pigs, a 20-Fr ATC tube was placed on one side and a 32-Fr standard tube on the other, and 120 mL of fresh blood was infused into each pleural space every 15 minutes for a total of 840 mL. EVALUATION: The amount of drainage for 2 hours with a 20-Fr ATC tube was significantly greater than that with the 32-Fr standard tube (525 ± 179 mL vs 183 ± 85 mL; p = 0.0032). CONCLUSIONS: This is the first time a smaller diameter tube has been shown to have better drainage in the setting of acute bleeding compared with larger diameter tubes.

Performance of bioprosthetic valves after glycerol dehydration, ethylene oxide sterilization, and rehydration.

OBJECTIVE: : Most commercially available bioprosthetic valves are stored in an aldehyde solution. We report a new alternative method: Self-expanding valves composed of dehydrated tissues with a high glycerin:water ratio can be collapsed into specially designed sheaths prior to sterilization for ease of delivery and storage. MATERIALS AND METHODS: : Changes in tissue dimension of five samples of bovine pericardium were evaluated from baseline after glycerol treatment, air-drying, ethylene oxide (EtO) sterilization, and rehydration with water. Three valves fabricated from glutaraldehyde cross-linked tissues, including porcine pericardial tissue, bovine pericardial tissue, and porcine aortic valve, were dehydrated through a proprietary glycerin-based process, collapsed, placed within a catheter, EtO sterilized, stored for up to 212 days, and rehydrated with water. These valves were characterized in a mock circulation by mounting them at the inlet portion of a pneumatic pump before dehydration and after rehydration to evaluate the effects of dehydration and rehydration on the valve performance. RESULTS: : Tissues treated with glycerol solution showed no significant changes in dimension from baseline after glycerol treatment, air-drying, EtO sterilization, and rehydration with water. In all the valves, pump flows reached the maximum output capacity of the pneumatic pump after rehydration without an increase in filling pressures as compared with those before dehydration. CONCLUSIONS: : This method for storing collapsible bioprosthetic valves using a proprietary glycerin-based process demonstrated excellent valve performance.

Direct endoscopy-guided mitral valve repair in the beating heart: an acute animal study.

OBJECTIVE: : The purpose of this study was to develop a new method for minimally invasive mitral valve repair under direct endoscopic visualization in the beating heart. METHODS: : Fiberoptic cardioscopy of the left heart was conducted in 12 calves. Systemic perfusion was maintained by cardiopulmonary bypass through a median sternotomy. A clear solution (Ringer's lactate) was temporarily administered via the pulmonary artery to flush out the pulmonary vasculature, and additional perfusion of the left heart chambers enhanced visualization of the intracardiac anatomy. The endoscope, with an open-ended transparent flexible outer sheath, was inserted through the left ventricular apex, and an endoscopic clip was used for edge-to-edge mitral valve repair. Hemodilution was avoided by the drainage of irrigation fluid via a left ventricular cannula. RESULTS: : Direct endoscopic visualization of the mitral valve in an in vivo beating heart was obtained clearly, avoiding systemic hemodilution. In the last experiment, edge-to-edge repair using an endoscopic clip was successfully performed. Use of an effective intracardiac irrigation method was important for successful image acquisition and achievement of repair procedures. CONCLUSIONS: : This acute animal study showed the technical feasibility of beating-heart mitral valve surgery under direct endoscopic imaging. Although this study was performed under open-chest conditions, our successful experiment is a first step toward closed-chest intracardiac surgery with direct endoscopic visualization.

Cardioscopy-guided surgery: intracardiac mitral and tricuspid valve repair under direct visualization in the beating heart.

OBJECTIVE: Cardioscopy is a novel imaging method that allows closed-chest, real-time fiberoptic imaging of intracardiac structures. This study tested the feasibility and safety of cardioscopy as a platform for mitral and tricuspid valve surgery in the beating heart. METHODS: Through a median sternotomy, cardiopulmonary bypass was established in 10 calves. Lactated Ringer's solution was administered through the pulmonary artery to eliminate residual blood volumes in the lung vasculature and was drained through a left ventricular cannula. A fiberoptic cardioscope within its translucent outer sheath was inserted through the left ventricle. Irrigating solution was continuously administered through the cardioscope sheath for clearer visualization. An endoscopic clip was used for edge-to-edge repair of the mitral and tricuspid valves. After mitral valve clipping, the cardioscope was inserted into the right ventricle. The solution was administered from the right atrium and continuously drained from the pulmonary artery. After tricuspid valve repair, the animal was weaned from cardiopulmonary bypass. RESULTS: Successful double-valve repair was carried out in all 10 cases. All calves were weaned from cardiopulmonary bypass with dobutamine only. Hematocrit values were maintained during the procedure (pre 29.0% ± 3.1% vs post 28.5% ± 3.6%, P = .70). CONCLUSIONS: This study showed the technical feasibility of beating heart valve surgery using direct cardioscopic visualization. Cardioscopy represents a promising platform for future interventions and surgery under direct visualization in the beating heart.

Mitral annular remodeling to treat functional mitral regurgitation: a pilot acute study in a canine model.

BACKGROUND: The aim of this study was to evaluate the feasibility and efficacy of the injection of a nonabsorbable substance into the base of the left ventricle (LV) to treat functional mitral regurgitation (MR). METHODS: Tyramine-based hyaluronan hydrogel was injected into the base of the LV of the beating heart in a canine model of rapid ventricular pacing-induced functional MR (n = 4). The severity of MR was evaluated by epicardial echocardiography before and after hydrogel injection. RESULTS: The injection improved MR grade from 3.4 +/- 0.8 to 1.3 +/- 0.5 (P = .006) without inducing hemodynamic instability or any evidence of myocardial ischemia. We noted significant decreases in the septal-lateral dimension at the mitral annulus (3.4 +/- 0.4 cm to 2.9 +/- 0.3 cm; P = .039) and MR volume (20.6 +/- 7.3 mm3 to 5.2 +/- 2.2 mm3; P = .044). CONCLUSIONS: A novel treatment consisting of hydrogel injection into the base of the LV between the 2 papillary muscles was found to be feasible and effective for reducing functional MR in a canine model.

In vivo biocompatibility evaluation of a new resilient, hard-carbon, thin-film coating for ventricular assist devices.

The purpose of this study was to evaluate in vivo the biocompatibility of BioMedFlex (BMF), a new resilient, hard-carbon, thin-film coating, as a blood journal bearing material in Cleveland Heart's (Charlotte, NC, USA) continuous-flow right and left ventricular assist devices (RVADs and LVADs). BMF was applied to RVAD rotating assemblies or both rotating and stator assemblies in three chronic bovine studies. In one case, an LVAD with a BMF-coated stator was also implanted. Cases 1 and 3 were electively terminated at 18 and 29 days, respectively, with average measured pump flows of 4.9 L/min (RVAD) in Case 1 and 5.7 L/min (RVAD) plus 5.7 L/min (LVAD) in Case 3. Case 2 was terminated prematurely after 9 days because of sepsis. The sepsis, combined with running the pump at minimum speed (2000 rpm), presented a worst-case biocompatibility challenge. Postexplant evaluation of the blood-contacting journal bearing surfaces showed no biologic deposition in any of the four pumps. Thrombus inside the RVAD inlet cannula in Case 3 is believed to be the origin of a nonadherent thrombus wrapped around one of the primary impeller blades. In conclusion, we demonstrated that BMF coatings can provide good biocompatibility in the journal bearing for ventricular assist devices.

In vivo evaluation of zirconia ceramic in the DexAide right ventricular assist device journal bearing.

Zirconia is a ceramic with material properties ideal for journal bearing applications. The purpose of this study was to evaluate the use of zirconium oxide (zirconia) as a blood journal bearing material in the DexAide right ventricular assist device. Zirconia ceramic was used instead of titanium to manufacture the DexAide stator housing without changing the stator geometry or the remaining pump hardware components. Pump hydraulic performance, journal bearing reliability, biocompatibility, and motor efficiency data of the zirconia stator were evaluated in six chronic bovine experiments for 14-91 days and compared with data from chronic experiments using the titanium stator. Pump performance data including average in vivo pump flows and speeds using a zirconia stator showed no statistically significant difference to the average values for 16 prior titanium stator in vivo studies, with the exception of a 19% reduction in power consumption. Indices of hemolysis were comparable for both stator types. Results of coagulation assays and platelet aggregation tests for the zirconia stator implants showed no device-induced increase in platelet activation. Postexplant evaluation of the zirconia journal bearing surfaces showed no biologic deposition in any of the implants. In conclusion, zirconia ceramic can be used as a hemocompatible material to improve motor efficiency while maintaining hydraulic performance in a blood journal bearing application.

Novel epicardial off-pump device for mitral regurgitation: acute evaluation.

OBJECTIVE: This study evaluates the ability of a novel epicardial annuloplasty device Mitral Touch (MAQUET Cardiovascular LLC, San Jose, CA, USA) to reduce functional mitral regurgitation (MR) in a rapid ventricular pacing-induced dilated cardiomyopathy model in dogs. METHODS: A median sternotomy was performed in 13 dogs after MR induction by rapid ventricular pacing (230 beats/min for an average of 35.6 + or - 12.8 days). Two-dimensional epicardial echocardiographic and haemodynamic measurements were performed to evaluate the baseline MR grade, the septal-lateral (S-L) dimension of the mitral annulus, mitral valve (MV) geometry and left ventricular function. The Mitral Touch was implanted by sliding the anterior arm onto the floor of the transverse sinus and positioning the posterior arm just apical to the atrioventricular groove on the left ventricular posterolateral wall. The 24-mm-long device was implanted in eight dogs, the 27-mm-long device in four and the 30-mm standard length device in one. MR grade, S-L dimension and haemodynamics data acquisition were immediately rechecked after device implantation. RESULTS: All implantations, which took only approximately 30s to deploy, were performed on beating hearts without cardiopulmonary bypass. In one early case, after extended manipulation with undersized devices, an atrial laceration was created and bleeding occurred. Design changes were made to eliminate this complication. The MR grade was significantly (p=0.003) reduced from 3.1 + or - 1.1 at baseline to 1.4 + or - 0.8 after device implantation. The S-L dimension at end of systole was also significantly (p=0.001) reduced from 2.7 + or - 0.4 cm at baseline to 2.3 + or - 0.3 cm after device implantation (% reduction: 15.1 + or - 10.6%). The mitral valve coaptation length was significantly (p=0.0001) increased from 0.36 + or - 0.11 cm to 0.50 + or - 0.08 cm, and the mitral valve tethering area was significantly (p=0.0003) decreased from 1.36 + or - 0.38 cm(2) to 0.81 + or - 0.29 cm(2) after Mitral Touch implantation. CONCLUSIONS: This new epicardial device was effective in significantly reducing MR and S-L dimensions acutely on the beating heart without requiring the use of cardiopulmonary bypass. Further studies are necessary to confirm the long-term maintenance of MR and S-L reductions.