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1.
Kyobu Geka ; 76(11): 928-932, 2023 Oct.
Article in Japanese | MEDLINE | ID: mdl-38056950

ABSTRACT

This is a 2-case report of concomitant left atrial( LA) surgical ablation through the left atrial appendage( LAA) for atrial fibrillation( AF) during aortic valve replacement( AVR). Case 1, a 74-year-old man, and Case 2, an 85-years-old woman, were presented for AVR and AF. Under the cardio-pulmonary bypass, right and left pulmonary vein isolations( PVIs) were performed with radiofrequency( RF) ablation devices. Through the opened LAA, an RF lesion was placed to connect the bilateral PVIs and the LAA, and another RF line was placed toward the mitral annulus. A right atrial( RA) isthmus ablation was also performed through a RA incision. Postoperatively, sinus rhythm and both RA and LA contraction were obtained, and have been maintained for 7.5 and 5 years without classⅠ/Ⅲ antiarrhythmic drugs in Case 1 and 2, respectively. This procedure is considered to be effective and safe, although further study is needed.


Subject(s)
Atrial Appendage , Atrial Fibrillation , Catheter Ablation , Male , Female , Humans , Aged, 80 and over , Aged , Atrial Appendage/diagnostic imaging , Atrial Appendage/surgery , Aortic Valve/surgery , Treatment Outcome , Heart Atria/surgery , Atrial Fibrillation/complications , Atrial Fibrillation/surgery , Catheter Ablation/adverse effects
2.
Kyobu Geka ; 75(2): 83-87, 2022 Feb.
Article in Japanese | MEDLINE | ID: mdl-35249081

ABSTRACT

This report presents a modified procedure of tricuspid valve ring annuloplasty (R-TAP) with posterior annular plication for functional tricuspid regurgitation (TR). Sutures on the native annulus were placed by a standard fashion in R-TAP, and those on the posterior annulus and its bilateral commissures were passed through in a narrow range between the 3 and 4 o'clock positions of the 26-mm ring. The other sutures were done with an usual manner and the ring was fixed to the annulus, resulting in the posterior annular plication( bicuspidization). Follow-up was performed for more than 5 years( mean: 7.9 years, range:5.5~11.5 years) by echocardiography in 13 cases. Postoperative TR reduced significantly to less than moderate, which was maintained during the entire follow-up period, even in the case with atrial fibrillation. There was no sign of tricuspid stenosis. R-TAP with posterior annular plication was feasible, reproducible, and effective, although further investigation is needed.


Subject(s)
Cardiac Valve Annuloplasty , Tricuspid Valve Insufficiency , Tricuspid Valve , Cardiac Valve Annuloplasty/methods , Echocardiography , Follow-Up Studies , Humans , Treatment Outcome , Tricuspid Valve/surgery , Tricuspid Valve Insufficiency/diagnostic imaging , Tricuspid Valve Insufficiency/surgery
3.
Kyobu Geka ; 73(9): 667-670, 2020 Sep.
Article in Japanese | MEDLINE | ID: mdl-32879269

ABSTRACT

This is a 3-case report of successful descending thoracic and thoracoabdominal aortic surgery by preserving the spinal perfusion artery (SPA) identified preoperatively. In Case 1, an 85-year-old woman, computed tomography (CT) showed Crawford type Ⅴ thoracoabdominal aortic aneurysm (TAAA:60 mm) and a SPA originated from L2. In Case 2, a 76-year-old man, CT revealed type Ⅳ TAAA( 58 mm) and a SPA originated from Th11. In Case 3, a 74-year-old man, CT detected an infectious pseudoaneurysm(44 mm) in the descending thoracic aorta with 2 SPAs originating from Th10 and L2. The ranges of graft replacement were Th7-Th12, Th12-L4, and Th8-Th10, respectively, while preserving all SPAs. All patients recovered well without postoperative neurological deficits. Although the protective effect of the SPA preservation against the spinal cord ischemia is still controversial, preoperative identification of the SPA was useful for planning a surgical strategy for descending thoracic and thoracoabdominal aortic repair surgery.


Subject(s)
Aortic Aneurysm, Abdominal , Aortic Aneurysm, Thoracic , Spinal Cord Ischemia , Aged , Aged, 80 and over , Arteries , Female , Humans , Male , Perfusion , Spinal Cord , Tomography, X-Ray Computed
4.
Kyobu Geka ; 72(13): 1085-1088, 2019 Dec.
Article in Japanese | MEDLINE | ID: mdl-31879385

ABSTRACT

This is a 2-case report of successful aortic repair surgery for the retrosternal giant aortic aneurysm. Our surgical strategy is "deep hypothermia and left ventricular( LV) unloading under cardiopulmonary bypass before approaching to the aortic aneurysm" in case of possible catastrophic bleeding. Case 1, a 64-year-old woman, had a retrosternal pseudoaneurysm (80 mm) at the distal anastomosis of a Dacron graft used to replace the ascending aorta 7 years before. An LV vent tube was cannulated via the right upper pulmonary vein through an inferior T-shaped ministernotomy. Case 2, an 86-year-old woman, had a retrosternal chronic aortic dissecting aneurysm (66 mm). An LV vent cannula was inserted via the LV apex through a left minithoracotomy. Arch replacement and ascending aorta replacement were performed in Case 1 and 2, respectively, without cardiac, neurological, or any other complications. This strategy is safe and useful in a case with complex aortic disease.


Subject(s)
Aneurysm, False , Aortic Aneurysm , Aortic Dissection , Aged, 80 and over , Aorta , Aorta, Thoracic , Female , Humans , Middle Aged
5.
Kyobu Geka ; 72(12): 969-973, 2019 Nov.
Article in Japanese | MEDLINE | ID: mdl-31701905

ABSTRACT

This is a 3-case report of mitral valve replacement (MVR) with an On-X mechanical valve followed up to 10 years. Case 1(64-year-old man) and case 2 (66-year-old woman) experienced traffic accident and traumatic event, respectively, in their chronic phase after MVR. Case 1 had multiple bone fractures of the bilateral lower limbs, which was followed by systemic infection and pyogenic spondylitis. He needed long-term antibiotics therapy for more than 4 years. Case 2 fell down at home and severely hit her head, which resulted in a traumatic subarachnoid hemorrhage. She was in a deep coma, and needed discontinuation of anticoagulation therapy for 4 weeks. Case1, 2, and 3(54-year-old man) are doing well in New York Heart Association functional class I without any valve-related thromboembolic or hemorrhagic events at 10, 9 and 8 years after MVR, respectively. On-X valve performance has also been found well maintained in all cases by echocardiography, even after traumatic accident or discontinuation of anticoagulation in Case 1 and 2. In this report, the On-X mechanical valve demonstrated good midterm result of its valve performance in the mitral position and its potential advantages in antithrombogenicity.


Subject(s)
Heart Valve Prosthesis Implantation , Heart Valve Prosthesis , Mitral Valve , Thromboembolism , Aged , Anticoagulants , Aortic Valve , Female , Humans , Male , Middle Aged , Treatment Outcome
6.
Kyobu Geka ; 68(7): 496-9, 2015 Jul.
Article in Japanese | MEDLINE | ID: mdl-26197823

ABSTRACT

This report discusses intraoperative endoscopic evaluation of the aortic valve performed in 2 cases of aortic valve repair. The "direct" or real image by the endoscopy helped to confirm the preoperatively-known lesion and even to detect a new legion which was not detected preoperatively. The endoscopy also enabled the evaluation of the aortic valve under the pressure-loaded condition without releasing the aortic clamp. Postoperative aortic regurgitation was grade I or less in both cases, although it progressed to grade II at 1 year in case 2. Echocardiographic parameters demonstrated no change in the size of the aortic root configuration for 8 and 5 years in case 1 and case 2, respectively. Intraoperative aortic endoscopy was useful to define the pathogenesis of aortic regurgitation and to evaluate the cusp repair procedures, which may contribute to a good mid-term result of aortic valve repair.


Subject(s)
Aortic Valve/surgery , Cardiac Surgical Procedures , Endoscopy , Humans , Male , Middle Aged , Plastic Surgery Procedures , Risk Factors , Treatment Outcome
7.
Ann Thorac Surg ; 92(5): 1911-3, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22051300

ABSTRACT

We describe a staged resternotomy technique using an inferior T-shaped ministernotomy for three redo cases with a retrosternal aortic arch aneurysm. To minimize the disadvantages of resternotomy during closed-chest hypothermia, an inferior T-shaped ministernotomy was performed before approaching the aneurysm. After establishment of the cardiopulmonary bypass with femoral or axillary arterial cannulation, or both, and right atrial drainage, a venting catheter was inserted into the left ventricle and core cooling was induced at 25°C. The retrosternal aneurysm was then exposed by additional superior sternotomy. Under hypotherma with antegrade cerebral perfusion, the distal side of a four-branched graft was anastomosed. During rewarming, reconstruction of the arch vessels and proximal anastomosis of the branched graft were performed. In the 3 patients operated on using this technique, there were no perioperative deaths or serious complications. This suggests that the technique can be safely performed and minimizes the disadvantages of the widely used resternotomy technique.


Subject(s)
Aortic Aneurysm, Thoracic/surgery , Sternotomy/methods , Humans , Reoperation
8.
ASAIO J ; 56(6): 497-503, 2010.
Article in English | MEDLINE | ID: mdl-20944501

ABSTRACT

This article describes the implantation techniques of two new stentless mitral bioprosthesis and their early echocardiographic performance in 12 acute sheep model. The first stentless mitral bioprosthesis (stentless bileaflet valve [SBV]) was designed as a bileaflet valve with sewing ring to suture down to the native mitral annulus. The other one (SBV with chordae) has two chordae-like structures to be attached to the head of the native papillary muscles. Valvar performance and cardiac function were evaluated by epicardial echocardiography at postimplant (Rest) and during dobutamine (DOB) stimulation. Postimplant echocardiography revealed normal leaflet opening with a large orifice area and unrestricted leaflets motion. In both valves, leaflet closure showed no systolic anterior motion, prolapse, or tethering. Mitral regurgitation grade 2 or higher was not detected in any of the experiments. Transvalvar pressure gradients at Rest and DOB were 2.3 ± 1.6 mm Hg and 2.5 ± 2.2 mm Hg in SBV and 1.8 ± 1.1 mm Hg and 2.3 ± 1.2 mm Hg in SBV with chordae, respectively. Both stentless bioprosthesis showed reliable valve performance and preserved cardiac function in the acute phase. Further chronic study is needed to evaluate the reliability of implantation procedures, valvar performance, and biocompatibility.


Subject(s)
Bioprosthesis , Heart Valve Prosthesis Implantation/methods , Heart Valve Prosthesis , Mitral Valve/surgery , Animals , Dobutamine , Echocardiography , Mitral Valve/diagnostic imaging , Mitral Valve/physiology , Models, Animal , Prosthesis Design , Sheep , Ventricular Function, Left
9.
Kyobu Geka ; 61(6): 449-53, 2008 Jun.
Article in Japanese | MEDLINE | ID: mdl-18536291

ABSTRACT

This is a report of 2 cases, in which preoperative 3-dimentional demonstration of the spinal cord artery with 64-row computed tomography was feasible, less invasive, less time-consuming, and helpful in making an interventional strategy for complex aortic disease, resulting in no postoperative paraplegia One was a 63-year-old man, who underwent total arch replacement and a long elephant trunk method for arch and descending aortic aneurysms. The length of the long elephant trunk was so determined that it ended between the descending aortic aneurysm and the origin of the spinal cord artery. The second case was a 59-year-old man, who underwent descending thoracic aorta replacement for type B aortic dissection. During the distal anastomosis, the dissection septa were trimmed in order to perfuse the blood into the true and 2 false channels, one of which was connected to the spinal cord artery. In this report, we are not suggesting that preservation of the demonstrated spinal cord artery is enough for spinal cord protection, because it is still controversial. Further study is needed to confirm the reliability and reproducibility of our methods.


Subject(s)
Angiography/methods , Aortic Diseases/surgery , Imaging, Three-Dimensional/methods , Paraplegia/prevention & control , Postoperative Complications/prevention & control , Spinal Cord/blood supply , Tomography, Spiral Computed/methods , Humans , Male , Middle Aged
10.
Kyobu Geka ; 61(3): 217-21, 2008 Mar.
Article in Japanese | MEDLINE | ID: mdl-18323188

ABSTRACT

In this report, aortic arch replacement was performed successfully in 2 cases with our modified method placing priority on the cardiac and cerebral reperfusion, resulting in no postoperative cardiac or neurological complication. One was a 63-year-old man with old cerebral infarction and ischemic heart disease, and the other was a 72-year-old man with severe stenosis of the left common carotid arteries. Our method is similar to so-called "arch first technique". First, the ascending aorta is clamped and proximal anastomosis is accomplished during core cooling, followed by reconstruction of the brachiocephalic arteries under deep hypothermic circulatory arrest. Then perfusion of the heart and brain is restarted, while distal anastomosis is performed. It was proved that the method had several possible advantages such as minimized duration of brain ischemia and deep hypothermia, and elimination of direct cannulation to the branches of the aortic arch and a separate perfusion circuit for the brain.


Subject(s)
Aorta, Thoracic/surgery , Aortic Aneurysm, Thoracic/surgery , Aortic Dissection/surgery , Blood Vessel Prosthesis Implantation/methods , Brain , Heart , Reperfusion/methods , Aged , Humans , Hypothermia, Induced , Male , Middle Aged
11.
J Thorac Cardiovasc Surg ; 133(4): 986-94, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17382639

ABSTRACT

OBJECTIVES: We have developed a stentless pericardial mitral valve prosthesis in 2 configurations; the purposes of this acute study in sheep were to assess (1) valve design and implant technique; (2) valve performance; and (3) acute effects on postimplant left ventricular function. METHODS: A stentless bovine pericardial bileaflet valve was developed with the intent to preserve annular-papillary muscle continuity. This valve, in 2 configurations-with (n = 5) and without (n = 5) flap chordae-was implanted in 10 sheep (mean weight 73 +/- 9 kg). Epicardial echocardiography was performed to assess valve performance. Load-independent left ventricular function was also estimated before implantation (baseline), 1 hour after discontinuing cardiopulmonary bypass (rest), and during dobutamine stimulation using conductance technology. RESULTS: Implantation was easily accomplished for both configurations. Both configurations had low transvalvular pressure (mean 2.1 +/- 1.2 mm Hg at rest; 2.2 +/- 1.0 mm Hg with dobutamine stimulation with flap chordae; 1.7 +/- 0.5 mm Hg and 1.6 +/- 0.3 mm Hg without flap chordae). No mitral regurgitation was observed in 8 sheep, and mild regurgitation was seen in 2 sheep. Compared with baseline, slope of maximum rate of change of left ventricular pressure-end-diastolic volume relation increased with stimulation both with flap chordae (+52 +/- 41 mm Hg x s(-1)x mL(-1), P = .0005) and without (+20 +/- 12 mm Hg x s(-1) x mL(-1), P = .003). CONCLUSIONS: Both configurations of this newly designed stentless mitral bioprosthesis, which preserves annular-papillary muscle continuity using different novel surgical implantation techniques, demonstrated reliable valve performance, with low transvalvular pressure gradients, minimal regurgitation, and acutely preserved postimplant left ventricular function. Further chronic study is needed to verify these results and evaluate reliability of implantation procedures, biocompatibility, and durability.


Subject(s)
Bioprosthesis , Heart Valve Prosthesis Implantation/instrumentation , Heart Valve Prosthesis , Ventricular Function, Left/physiology , Animals , Feasibility Studies , Mitral Valve , Models, Animal , Prosthesis Design , Sheep , Stents
12.
J Am Soc Echocardiogr ; 18(9): 959-63, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16153522

ABSTRACT

We compared the impact of annulus size and valve deformation (tethering) on mitral regurgitation in the animal dilated cardiomyopathy model, and assessed if acute left ventricular volume changes affect mitral annulus dimensions. We performed 3-dimensional echocardiography in 30 open-chest dogs with pacing-induced cardiomyopathy. Mitral annulus area was calculated from its two orthogonal diameters, whereas valve tethering was quantified by valve tenting area measurement. Mitral valve regurgitant volume showed the highest correlation with annulus area (r = 0.64, P < .001), left atrial volume (r = 0.40, P < .01), and left ventricular end-diastolic volume (r = 0.37, P < .01). Regurgitant volume showed poorer correlation with valve tethering in both septolateral and intercommissural planes (r = 0.35 and r = 0.31, P < .05 for both). Annulus dimensions correlated with acute changes of left ventricular end-diastolic volume (r = 0.68, P = .002). Mitral annulus dilation is the strongest predictor of functional mitral regurgitation in this animal dilated cardiomyopathy model.


Subject(s)
Cardiomyopathy, Dilated/diagnostic imaging , Mitral Valve Insufficiency/diagnostic imaging , Mitral Valve Stenosis/diagnostic imaging , Mitral Valve/diagnostic imaging , Ventricular Dysfunction, Left/diagnostic imaging , Animals , Cardiomyopathy, Dilated/etiology , Dogs , Echocardiography/methods , Mitral Valve Insufficiency/etiology , Mitral Valve Stenosis/etiology , Reproducibility of Results , Sensitivity and Specificity , Statistics as Topic , Ventricular Dysfunction, Left/etiology
13.
Med Sci Monit ; 11(6): BR147-153, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15917708

ABSTRACT

BACKGROUND: Although left ventricular (LV) contractility in atrial fibrillation (Af) is known to change in a beat-to-beat fashion, little is known about the changes in LV compliance in Af. MATERIAL/METHODS: We experimentally induced tachycardic Af (average heart rate - 154 beats per minute) in 18 sheep. LV volume and pressure were simultaneously monitored using a conductance catheter. LV end-diastolic volume (V(ED)) and pressure (P(ED)) were plotted in a beat-to-beat fashion and fitted to the following exponential equation (P(ED)=gamma x e(b x V(ED))) in each animal. A random effects model was constructed to determine if the intercepts and slopes differ. RESULTS: In all animals, those plots after the induction of Af fit quite well to the exponential function (r=0.834+/-0.184) by gating short preceding interval (RR1) beats. By simply taking the natural logarithm of both sides in the equation, the linear relationship (ln(P(ED)) =alpha+ betaxV(ED), where a = lng) was observed in all animals before (normal sinus rhythm, NSR) and after the induction of Af. Only two of 18 intercepts and four of 18 slopes deviate between NSR and Af. Most interestingly, the random effects model clearly detailed that the average animal had intercepts and slopes that were not discernibly different between NSR and Af. CONCLUSIONS: Unlike LV contractility, myocardial compliance did not change after the acute induction of Af. These interesting results may give us insights into the understanding of the physiology in acute rapid Af.


Subject(s)
Atrial Fibrillation/physiopathology , Heart/physiopathology , Myocardial Contraction/physiology , Animals , Blood Pressure/physiology , Diastole , Disease Models, Animal , Electrocardiography , Hemodynamics , Sheep , Ventricular Function, Left
14.
ASAIO J ; 51(1): 82-4, 2005.
Article in English | MEDLINE | ID: mdl-15745140

ABSTRACT

The purpose of this study was to evaluate the ex vivo effects of the Coapsys device upon functional mitral regurgitation (MR) in human hearts. We used seven excised hearts from patients who underwent cardiac transplantation. All patients had functional MR of grade 2 or greater associated with dilated (n = 3) or ischemic (n = 4) cardiomyopathy. After the aortic valve was removed, the left ventricle was pressurized from the aorta with saline at a constant pressure. The degree of MR was then subjectively graded from the opened left atrium (from 0 to 4). The last three studies included volumetric measurements of MR. By tightening the device, the mean MR grade was reduced from 3.3 +/- 0.8 to 1.1 +/- 0.4 (p = 0.0002). In the quantitative analysis, mean regurgitation volume was reduced from 1,108 +/- 1,134 ml/min to 236 +/- 89 ml/min (p = not significant). The mitral annular septal-lateral dimension decreased from 2.0 +/- 0.3 cm to 1.6 +/- 0.5 (p = 0.043). The Coapsys device reduced functional MR in the ex vivo study using excised dilated hearts.


Subject(s)
Heart Valve Prosthesis , Heart-Assist Devices , Mitral Valve Insufficiency/surgery , Cardiomyopathy, Dilated/physiopathology , Cardiomyopathy, Dilated/surgery , Heart Valve Prosthesis Implantation , Heart Ventricles/physiopathology , Humans , Mitral Valve Insufficiency/pathology , Mitral Valve Insufficiency/physiopathology , Models, Cardiovascular , Myocardial Ischemia/pathology , Myocardial Ischemia/physiopathology , Myocardial Ischemia/surgery , Ventricular Dysfunction, Left/pathology , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Left/surgery
15.
J Thorac Cardiovasc Surg ; 128(1): 38-43, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15224019

ABSTRACT

OBJECTIVES: Activation of the neuroendocrine axis in congestive heart failure is of prognostic significance, and neurohumoral blocking therapy prolongs survival. The hypothesis that surgical reduction of left ventricular size and function decreases neuroendocrine activation is less established. We evaluated the neurohormonal response to left ventricular reconstruction surgery in ischemic cardiomyopathy. METHODS: Norepinephrine, plasma renin activity, and angiotensin II were measured in 10 patients before and 12 months after left ventricular reconstruction. In an additional 5 patients, brain natriuretric peptide was measured before and 3 months postoperatively. Three-dimensional cardiovascular imaging was used to assess ejection fraction and left ventricular end-diastolic volume index. RESULTS: Concurrent with improvements of New York Heart Association functional class (2.9 +/- 0.5 preoperatively vs 2.0 +/- 0.4 postoperatively, P <.001), ejection fraction (23.9% +/- 6.6% vs 36.2% +/- 6.2%, P <.01), and left ventricular end-diastolic volume index (140.8 +/- 33.8 mL/m(2) vs 90.6 +/- 18.3 mL/m(2), P <.01), considerable reductions were observed for median plasma profiles of norepinephrine (562.0 pg/mL vs 319.0 pg/mL, P <.05), plasma renin activity (5.75 microg/L/h vs 3.45 microg/L/h, P <.05), angiotensin II (41.0 ng/mL vs 23.0 ng/mL, P =.051), and brain natriuretric peptide (771.0 pg/mL vs 266.0 pg/mL, P <.05). The more plasma renin activity or angiotensin II decreased after left ventricular reconstruction, the higher was the increase in ejection fraction (R = -.745, P <.05 [plasma renin activity]; R = -.808, P <.05 [angiotensin II]). CONCLUSIONS: Surgical improvements of ejection fraction and left ventricular end-diastolic volume index by left ventricular reconstruction were accompanied by improvement of both the neuroendocrine activity and the functional status in patients with congestive heart failure. Whether this favorable neurohormonal response is predictive of an improved survival requires further evaluation.


Subject(s)
Cardiac Surgical Procedures , Cardiomyopathies/blood , Cardiomyopathies/surgery , Myocardial Ischemia/blood , Myocardial Ischemia/surgery , Neurotransmitter Agents/metabolism , Ventricular Function, Left/physiology , Aged , Angiotensin II/blood , Biomarkers/blood , Cardiomyopathies/physiopathology , Female , Follow-Up Studies , Heart Failure/blood , Heart Failure/physiopathology , Heart Failure/surgery , Heart Ventricles/metabolism , Heart Ventricles/physiopathology , Heart Ventricles/surgery , Humans , Male , Middle Aged , Myocardial Ischemia/physiopathology , Natriuretic Peptide, Brain/blood , Norepinephrine/blood , Renin/metabolism , Statistics as Topic , Stroke Volume/physiology , Treatment Outcome
16.
Ann Thorac Surg ; 77(6): 2103-10, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15172276

ABSTRACT

BACKGROUND: Left ventricular assist system technologies are currently being developed as effective alternatives to cardiac transplantation. In this study, in vivo testing of the Arrow International CorAide left ventricular assist system was conducted to determine its preclinical readiness based on demonstrated system performance and biocompatibility. METHODS: Arrow International CorAide blood pump assemblies were implanted in 7 calves for 1-month (n = 4) and 3-month (n = 3) durations without the use of chronic anticoagulation therapy. Hemodynamic performance, physiologic pump control, end-organ function, and device-related adverse events were evaluated during the studies and at autopsy. RESULTS: Hemodynamics were stable in all cases with a mean pump flow of 4.1 +/- 0.8 L/min and a mean arterial pressure of 101 +/- 4 mm Hg. In all calves, renal and hepatic function remained normal with no incidence of hemolysis, infection, bleeding, or embolism. The CorAide physiologic control algorithm demonstrated appropriate pump speed and flow adjustments in response to physiologically induced inputs, and the system's external electronic components demonstrated no hardware or software malfunction. All 7 cases were sacrificed electively. Autopsy revealed no sign of end-organ disease on gross and histologic examinations, and no device failure, malfunction, or mechanical wear of the pump blood-bearing surfaces was found. CONCLUSIONS: The Arrow CorAide left ventricular assist system demonstrated effective pump performance and good biocompatibility with no incidence of device-related adverse events. This system has completed its preclinical readiness testing and is approved for clinical trials in Europe in 2003.


Subject(s)
Heart-Assist Devices , Animals , Anticoagulants/administration & dosage , Cattle , Equipment Design , Heart-Assist Devices/adverse effects , Hematocrit , Hemodynamics , Hemoglobins/analysis , Liver/physiology , Platelet Count
17.
J Am Soc Echocardiogr ; 17(5): 411-7, 2004 May.
Article in English | MEDLINE | ID: mdl-15122179

ABSTRACT

We assessed the effects of implantation of Myosplint (Myocor, Maple Grove, Minn), a device that changes left ventricular (LV) cross-sectional shape from circular to bilobar, on regional LV function. A total of 10 open-chest dogs with tachycardia-induced cardiomyopathy were studied before and after Myosplint implantation. LV cross-sectional epicardial echocardiography at the papillary muscle level was performed along with acquisition of hemodynamic data. LV normalized thickening, fractional thickening, end-diastolic thickness, and end-diastolic curvatures were calculated for 10 LV segments. Myosplint implantation did not affect LV hemodynamics, but decreased average end-diastolic curvature (P <.0001) and increased its segmental heterogeneity (P <.0001). There was no change in average fractional thickening, whereas normalized thickening increased (P =.05). In contrast, segmental heterogeneity of both normalized and fractional thickening increased (P =.02 and P =.01, respectively). Structural modeling confirmed that Myosplint implantation increases regional stress heterogeneity and curvature heterogeneity. LV cross-sectional shape markedly affects regional LV performance.


Subject(s)
Cardiomyopathies/diagnostic imaging , Cardiomyopathies/physiopathology , Heart-Assist Devices , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/physiopathology , Animals , Cardiomyopathies/pathology , Dogs , Models, Cardiovascular , Ultrasonography , Ventricular Dysfunction, Left/pathology
18.
Heart Surg Forum ; 7(2): E117-21, 2004 Apr 01.
Article in English | MEDLINE | ID: mdl-15138085

ABSTRACT

BACKGROUND: Myocor developed a unique system, the Coapsys annuloplasty system, to treat functional mitral regurgitation (MR) without cardiopulmonary bypass (CPB). This study was conducted to test the feasibility of the Coapsys implantation procedure in a canine functional MR model. METHODS: Functional MR with heart failure was induced in 9 dogs by rapid ventricular pacing (230 beats/min for 30 +/- 4 days). The Coapsys device, which consists of anterior and posterior epicardial pads connected by a subvalvular chord, was then surgically implanted. Under epicardial echocardiographic guidance, we placed the Coapsys device across the left ventricular chamber using the delivery instrument and needle assembly. We sized the Coapsys device by drawing the posterior leaflet and annulus toward the anterior leaflet with the sizing instrument. Final device size was selected when MR was minimized or eliminated as assessed by 2-dimensional color Doppler echocardiography. RESULTS: In all cases, we successfully implanted the Coapsys device without CPB or atriotomy. MR was reduced an average of 2 grades. No adverse events, such as hemodynamic compromise or structural valve damage, were noted. CONCLUSION: Coapsys device implantation was feasible and safe on a beating canine heart. All accessory tools used for device implantation were found useful.


Subject(s)
Disease Models, Animal , Heart Valve Prosthesis Implantation/methods , Heart Valve Prosthesis , Mitral Valve Insufficiency/surgery , Animals , Cardiopulmonary Bypass , Dogs , Equipment Design , Equipment Failure Analysis , Heart Atria/surgery , Heart Valve Prosthesis Implantation/instrumentation
19.
J Thorac Cardiovasc Surg ; 127(4): 1068-76; discussion 1076-7, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15052204

ABSTRACT

OBJECTIVE: We evaluated the capability of the Myocor Coapsys device (Myocor, Inc, Maple Grove, Minn) to reduce functional mitral regurgitation in a canine model of dilated cardiomyopathy. METHODS: Functional mitral regurgitation with heart failure was induced in 7 dogs by rapid ventricular pacing. The Coapsys device, which consists of anterior and posterior epicardial pads connected by a subvalvular chord, was then implanted. Heart failure was maintained by continued pacing for 8 weeks. Hemodynamic and echocardiographic measurements were performed at pre- and postsizing and after 8 weeks. The Coapsys subvalvular chord was cut to verify that maintenance of valve competency was due to the device. RESULTS: All implants were performed off-pump without atriotomy. Mitral regurgitation was reduced in all animals; mean mitral regurgitation grade was reduced from 2.9 +/- 0.7 to 0.7 +/- 0.8 (P =.00005) and was maintained at 0.8 +/- 0.8 after 8 weeks, without hemodynamic compromise or structural damage to the mitral valve. Mitral regurgitation returned to 3.6 +/- 0.8 (P =.102 versus presizing) after cutting the Coapsys subvalvular chord. CONCLUSION: The Coapsys device consistently and chronically reduced functional mitral regurgitation. This device is in clinical trials in the United States.


Subject(s)
Heart-Assist Devices , Mitral Valve Insufficiency/physiopathology , Mitral Valve Insufficiency/surgery , Animals , Aortic Valve Insufficiency/diagnostic imaging , Aortic Valve Insufficiency/physiopathology , Aortic Valve Insufficiency/surgery , Cardiomyopathy, Dilated/diagnostic imaging , Cardiomyopathy, Dilated/physiopathology , Cardiomyopathy, Dilated/surgery , Diastole/physiology , Disease Models, Animal , Dogs , Echocardiography , Heart Valve Prosthesis Implantation , Heart Ventricles/diagnostic imaging , Heart Ventricles/physiopathology , Mitral Valve Insufficiency/diagnostic imaging , Models, Cardiovascular , Severity of Illness Index , Stroke Volume/physiology , Systole/physiology , Time , Treatment Outcome , Tricuspid Valve Insufficiency/diagnostic imaging , Tricuspid Valve Insufficiency/physiopathology , Tricuspid Valve Insufficiency/surgery
20.
Eur J Cardiothorac Surg ; 25(3): 352-7, 2004 Mar.
Article in English | MEDLINE | ID: mdl-15019660

ABSTRACT

OBJECTIVE: The objective of this study was to evaluate the changes in mitral annular and left ventricular dimensions and left ventricular pressure-volume relations produced by the Myocor Coapsys device that has been developed to treat functional mitral regurgitation (MR) off-pump. METHODS: The Coapsys device, which consists of anterior and posterior epicardial pads connected by a sub-valvular chord, was implanted in seven dogs with functional MR resulting from pacing induced cardiomyopathy. The Coapsys device was then sized by drawing the posterior leaflet and annulus toward the anterior leaflet. During sizing, MR grade was assessed using color flow Doppler echocardiography. Final device size was selected when MR was eliminated or minimized. Following implantation, heart failure was maintained by continued pacing for a period of 8 weeks. Mitral annular and left ventricular dimensions and left ventricular pressure-volume relations were evaluated by two-dimensional echocardiography and a conductance catheter, respectively, at pre-sizing, post-sizing, and after 8 weeks. RESULTS: All implants were performed on beating hearts without cardiopulmonary bypass. Mean MR grade was reduced from 2.9+/-0.7 at pre-sizing to 0.7+/-0.8 at post-sizing (P<0.001), and was maintained at 0.8+/-0.8 after 8 weeks (P<0.01). The septal-lateral dimensions were significantly reduced at both mitral annular level [2.4+/-0.2 cm at pre-sizing, 1.5+/-0.3 cm at post-sizing (P<0.001) and 1.8+/-0.3 cm after 8 weeks (P<0.05)] and mid-papillary level [4.1+/-0.4 cm at pre-sizing, 2.4+/-0.2 cm at post-sizing (P<0.001) and 3.3+/-0.4 cm after 8 weeks (P<0.001)]. The end-systolic pressure-volume relation shifted leftward at post-sizing with a significantly steeper slope (P=0.03). There was a significant (P=0.03) leftward shift of the end-diastolic pressure-volume relation at post-sizing. After 8 weeks, these changes in pressure-volume relations tended to return to pre-sizing relations. CONCLUSIONS: The Coapsys device significantly reduced MR by treating both the mitral annular dilatation and the papillary muscle displacement. Despite these significant dimensional changes, the Coapsys device did not negatively affect the left ventricular pressure-volume relations.


Subject(s)
Heart Valve Prosthesis , Mitral Valve Insufficiency/surgery , Animals , Blood Pressure/physiology , Cardiac Pacing, Artificial , Cardiac Volume/physiology , Dogs , Mitral Valve Insufficiency/pathology , Mitral Valve Insufficiency/physiopathology , Myocardial Contraction/physiology , Ventricular Dysfunction, Left/pathology , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Left/surgery
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