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Biomedical subjects

Antonio F Corno

Publications and source records attributed to Antonio F Corno.

At least 19 recordsLinked to original sources
PubMed2006

Results of surgery for Ebstein anomaly: a multicenter study from the European Congenital Heart Surgeons Association.

OBJECTIVE: Since most centers' experience with Ebstein anomaly is limited, we sought to analyze the collective experience of participating institutions of the European Congenital Heart Surgeons Association with surgery for this rare malformation. METHODS: The records of all 150 patients (median age 6.4 years) who underwent surgery for Ebstein anomaly in the 13 participating Association centers between January 1992 and January 2005 were reviewed retrospectively. Patients with congenitally corrected transposition were excluded. RESULTS: Most patients (81%) had Ebstein disease type B or C and significant functional impairment (61% in New York Heart Association class III or IV) and 16% had prior operations. Surgical procedures (n = 179) included valve replacement (n = 60, 33.5%), valve repair (n = 49, 27.3%), 1(1/2) ventricle repair (n = 46, 25.6%), palliative shunt (n = 13, 7.26%), and other complex procedures (n = 11, 6.14%). There were 20 hospital deaths (operative mortality 13.3%) after valve replacement in 5 patients, valve repair in 3, 1(1/2) ventricle repair in 7, palliative procedures in 3, and miscellaneous procedures in 2. Younger age and palliative procedures were univariate risk factors for operative death, but only age was an independent predictor on multivariable analysis. CONCLUSIONS: Most patients coming to surgery presented in childhood and were significantly symptomatic. More than half underwent valve replacement or repair, but a considerable proportion had severe disease necessitating 1(1/2) ventricle repair or palliative procedures. Operative mortality did not differ significantly among repair, replacement, and 1(1/2) ventricle repair but was associated with palliative procedures for severe disease early in life, young age being the only independent predictor of operative death.

Adolescent↗
PubMed2006

Brief reoxygenation episodes during chronic hypoxia enhance posthypoxic recovery of LV function: role of mitogen-activated protein kinase signaling pathways.

Children with congenital cyanotic heart defects have worse outcomes after surgical repair of their heart defects compared with noncyanotic ones. Institution of extracorporeal circulation in these children exposes the cyanotic heart to reoxygenation injury. Mitogen-activated protein kinase (MAPK) signaling cascades are major regulators of cardiomyocyte function in acute hypoxia and reoxygenation. However, their roles in chronic hypoxia are incompletely understood. We determined myocardial activation of the three major MAPKs, c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase-1/2 (ERK1/2), and p38-MAPK in adult rats exposed to hypoxia (FIO2=0.10) for varying periods of time. Myocardial function was analyzed in isolated perfused hearts. Acute hypoxia stimulated JNK and p38-MAPK activation. Chronic hypoxia (2 weeks) was associated with increased p38-MAPK (but not JNK) activation, increased apoptosis, and impaired posthypoxic recovery of LV function. Brief normoxic episodes (1 h/day) during chronic hypoxia abolished p38-MAPK activation, stimulated MEK-ERK1/2 activation modestly, and restored posthypoxic LV function. In vivo p38-MAPK inhibition by SB203580 or SB202190 in chronically hypoxic rats restored posthypoxic LV function. These results indicate that sustained hypoxemia maintains p38-MAPK in a chronically activated state that predisposes to myocardial impairment upon reoxygenation. Brief normoxic episodes during chronic hypoxia prevent p38-MAPK activation and restore posthypoxic recovery of myocardial function.

Animals↗
PubMed2006

The helical ventricular myocardial band of Torrent-Guasp: potential implications in congenital heart defects.

The new concepts of cardiac anatomy and physiology, based on the observations made by Francisco Torrent-Guasp's discovery of the helical ventricular myocardial band, can be useful in the context of the surgical strategies currently used to manage patients with congenital heart defects. The potential impact of the Torrent-Guasp's Heart on congenital heart defects have been analyzed in the following settings: ventriculo-arterial discordance (transposition of the great arteries), double (atrio-ventricular and ventriculo-arterial) discordance (congenitally corrected transposition of the great arteries), Ebstein's anomaly, pulmonary valve regurgitation after repair of tetralogy of Fallot, Ross operation, and complex intra-ventricular malformations. The functional interaction of right and left ventricles occurs not only through their arrangements in series but also thanks to the structural spiral features. Changes in size and function of either ventricle may influence the performance of the other ventricle. The variety and complexity of congenital heart defects make the recognition of the relationship between form and function a vital component, especially when compared to acquired disease. The new concepts of cardiac anatomy and function proposed by Francisco Torrent-Guasp, based on his observations, should stimulate further investigations of alternative surgical strategies by individuals involved with the management of patients with congenital heart defects.

Heart↗
PubMed2006

The helical ventricular myocardial band: global, three-dimensional, functional architecture of the ventricular myocardium.

We are currently witnessing the advent of new diagnostic tools and therapies for heart diseases, but, without serious scientific consensus on fundamental questions about normal and diseased heart structure and function. During the last decade, three successive, international, multidisciplinary symposia were organized in order to setup fundamental research principles, which would allow us to make a significant step forward in understanding heart structure and function. Helical ventricular myocardial band of Torrent-Guasp is the revolutionary new concept in understanding global, three-dimensional, functional architecture of the ventricular myocardium. This concept defines the principal, cumulative vectors, integrating the tissue architecture (i.e. form) and net forces developed (i.e. function) within the ventricular mass. Here we expose the compendium of Torrent-Guasp's half-century long functional anatomical investigations in the light of ongoing efforts to define the integrative approach, which would lead to new understanding of the ventricular form and function by linking across multiple scales of biological organization, as defined in ongoing Physiome project. Helical ventricular myocardial band of Torrent-Guasp may also, hopefully, allow overcoming some difficulties encountered in contemporary efforts to create a comprehensive mathematical model of the heart.

Animals↗
PubMed2006

Intra-aortic balloon pumping in children undergoing cardiac surgery: an update of the Liverpool experience.

OBJECTIVE: Intra-aortic balloon pumping in children remains a rarity. We report our experience in supporting pediatric cardiac surgical patients with intra-aortic balloon pumping. METHODS: We reviewed the cases of 24 children supported with intra-aortic balloon pumping after cardiac surgery in our institution from 1994 through 2003. RESULTS: Mean age at the time of the operation was 5.0 +/- 5.6 years (range, 7 days-17.5 years). Ten patients were infants less than 6 months old. Mean weight was 18.9 +/- 18.1 kg (range, 3.5-58.7 kg). Indications for intra-aortic balloon pump deployment were postoperative hemodynamic deterioration (n = 11, 8 survivors), failure to wean off cardiopu(n = 7, 5 survivors), and prophylaxis before weaning off cardiopulmonary bypass (n = 6, 5 survivors). The balloon was inserted through the ascending aorta in infants and through the femoral artery in children. Eighteen children (7 infants) were weaned off the intra-aortic balloon pump successfully (intra-aortic balloon pump survival, 75%). Mean duration of intra-aortic balloon pump support was 121.3 +/- 140.60 hours (range, 8-670 hours). There were 3 post-intra-aortic balloon pump in-hospital deaths (survival to hospital discharge, 62.5%). Severe intra-aortic balloon pump-related complications were mesenteric ischemia in 1 patient and lower limb ischemia requiring intra-aortic balloon pump removal in 1 patient. At a mean follow-up of 85 +/- 31 months (range, 18-124 months), all 15 long-term survivors were alive and well. CONCLUSIONS: Use of an intra-aortic balloon pump is an effective modality of cardiac support in properly selected pediatric cardiac surgical patients with refractory low cardiac output. It can be safely used in small infants and neonates. In selected cases with known left ventricular dysfunction, there is a place for prophylactic use of an intra-aortic balloon pump.

Adolescent↗
PubMed2005

The non-circular shape of FloWatch-PAB prevents the need for pulmonary artery reconstruction after banding. Computational fluid dynamics and clinical correlations.

OBJECTIVE: To evaluate the differences between non-circular shape of FloWatch-PAB and conventional pulmonary artery (PA) banding. METHODS: Geometrical analysis. Conventional banding and FloWatch-PAB perimeters were plotted against cross-sections. Computational fluid dynamics (CFD) model. CFD compared non-circular FloWatch-PAB cross-sections with conventional banding regarding pressure gradients. Clinical data. Seven children, median age 2 months (7 days to 3 years), median weight 4.2 kg (3.2-9.8 kg), with complex congenital heart defects underwent PA banding with FloWatch-PAB implantation. RESULTS: Geometrical analysis. Conventional banding: progressive reduction of cross-sections was accompanied by progressive reduction of PA perimeters. FloWatch-PAB: with equal reduction of cross-sections the PA perimeter remained constant. CFD model. Non-circular and circular banding provided same trans-banding pressure gradients for same cross-sections at any given flow. Clinical data. Mean PA internal diameter at banding was 13.3+/-4.5 mm. After a mean interval of 5.9+/-3.7 months, all children underwent intra-cardiac repair and simple FloWatch-PAB removal without PA reconstruction. Mean PA internal diameter with FloWatch-PAB removal increased from 3.0+/-0.8 to 12.4+/-4.5 mm (normal mean internal diameter for the age=9.9+/-1.6). No residual pressure gradient was recorded in correspondence of the site of the previous FloWatch-PAB implantation in 6/7 patients, 10 mmHg peak and 5 mmHg mean gradient in 1/7. CONCLUSIONS: The non-circular shape of FloWatch-PAB can replace conventional circular banding with the following advantages: (a) the pressure gradient will remain essentially the same as for conventional circular banding for any given cross-section, but with significantly smaller reduction of PA perimeter; and (b) PA reconstruction at the time of de-banding for intra-cardiac repair can be avoided.

Blood Vessel Prosthesis↗
PubMed2005

Pulmonary artery banding.

Pulmonary artery banding is a palliative surgical procedure used to treat functionally univentricular hearts, multiple ventricular septal defects and complete atrioventricular septal defects. Pulmonary artery banding has recently gained in interest for left ventricular retraining and hypoplastic left heart malformations. The indication for pulmonary artery banding is limited by several factors: difficulty of determining optimal band tightness, influence of perioperative variables with mutual interference, agerelated variability of the ventricular adaptive response, difficulty of securing sufficiently tight banding in older children, repeated surgical procedures needed to adjust the band perimeter, long periods under intensive respiratory and/or pharmacological support, and the frequent need for reconstruction of the pulmonary artery at intracardiac repair. The need for adjustable banding has now been met by the clinical availability of telemetrically controlled adjustable pulmonary artery banding (FloWatch, EndoArt, Lausanne, Switzerland), which has been successfully tested in clinical practice after favourable evaluation in animal experiments. This new wireless, battery free, implantable device (FloWatch), allows repeated progressive occlusion and reopening of the device by remote control, at the desired percentage occlusion, without the need for reoperation to adjust the band. The introduction of FloWatch has brought substantial changes in the management of patients with increased pulmonary artery blood flow and pressure, a reduction in the mortality and morbidity associated with conventional banding, and significant shortening of intensive care unit and hospital stay. New therapeutic strategies could well extend the applicability of this device in patients with congenital heart defects.

Equipment Design↗
PubMed2005

Borderline left ventricle.

The first problem to solve when dealing with the topic 'borderline left ventricle' is to find the appropriate definition. Several parameters have been taken into consideration, either morphometric (diameter of the mitral valve, indexed mitral valve area, left ventricular inflow dimension, left ventricular cross-sectional area, ratio between the apex-to-base left ventricular dimension and right ventricular dimension, left ventricular long axis to heart long axis ratio, left ventricular end diastolic volume, left ventricular mass index, ratio of the right/left ventricular wall thickness, presence of endocardial fibroelastosis, cardiac apex not formed by the left ventricle, diameter of the ventriculo-aortic junction, diameter of the aortic valve annulus and indexed aortic root diameter) as well as functional (left ventricular ejection fraction, left ventricular end diastolic pressure, mean pulmonary artery pressure, direction of the blood flow in the ascending aorta and at the level of the patent ductus arteriosus). Pre-operative determination whether the left ventricle is adequate to sustain the systemic circulation, or it may became adequate with the available surgical approaches, and therefore a bi-ventricular type of repair is feasible, can be extremely difficult, particularly in the presence of a 'borderline left ventricle'. In the clinical practice pediatric cardiologists and cardiac surgeons are faced with the problem of the 'borderline left ventricle' in four different groups of congenital heart defects: (a) aortic valve stenosis, (b) aortic coarctation, with or without hypoplastic aortic arch, (c) hypoplastic left heart complex, (d) right ventricular pressure and/or volume overload. In all the above situations in the presence of a left ventricle smaller than normal a very exhaustive approach has been reviewed in the decision making process, taking in account the literature reports as well as the personal experience. In each patient with 'borderline left ventricle' the elements to be considered for the decision making process between uni- and bi-ventricular type of repair, or for less ideal options of management, are the following: morphometric and functional parameters, hemodynamic data, available surgical options, results of the personal and institutional experience.

Aorta, Thoracic↗
PubMed2005

Cybertools improve reaction time in open heart surgery.

OBJECTIVE: Head-up displays allow the surgeons to simultaneously view the patient and the patient's vital parameters (ECG, blood pressure, etc.) using vision-through over a wireless net, potentially enhancing the speed, accuracy and safety of surgical decisions. The aim was to assess surgical reaction time to AFIB, bigeminy, trigeminy, VTACH, and VFIB and concentration during a surgical intervention comparing standard and cyber tools monitoring. METHODS: Using a patient simulator for beating heart surgery able to emulate heart signals and motion (arrhythmias) a group of surgeons performed coronary bypass procedures. Measurements of reaction time, efficiency of the surgeon, time elapsed to display a coronary angiography in a realistic surgical environment were taken. RESULTS: The duration to accomplish the experiment is not different between groups (cyber vs. standard) reaction times, however, are significantly decreased for cyber by a mean of 33%. There is also a measured time difference for displaying a coronary angiography within the head-up display as compared to a remote console. CONCLUSIONS: During surgery, modern cyber tools allow for significant improvements of reaction time and concentration due to real time access to vital information.

Coronary Artery Bypass↗
PubMed2005

Towards new understanding of the heart structure and function.

Structure and function in any organ are inseparable categories, both in health and disease. Whether we are ready to accept, or not, many questions in cardiovascular medicine are still pending, due to our insufficient insight in the basic science. Even so, any new concept encounters difficulties, mainly arising from our inert attitude, which may result either in unjustified acceptance or denial. The ventricular myocardial band concept, developed over the last 50 years, has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium. After more than five centuries long debate on macroscopic structure of the ventricular myocardium, this concept has provided a promising ground for its final understanding. Recent validations of the ventricular myocardial band, reviewed here, as well as future research directions that are pointed out, should initiate much wider scientific interest, which would, in turn, lead to reconciliation of some exceeded concepts about developmental, electrical, mechanical and energetical events in human heart. The benefit of this, of course, would be the most evident in the clinical arena.

Biomechanical Phenomena↗
PubMed2004

Early clinical results of the telemetric adjustable pulmonary artery banding FloWatch-PAB.

BACKGROUND: Adjustment of pulmonary artery banding (PAB) may be a challenging procedure in complex congenital heart defects. Whatever the technique used, subsequent re-operations are frequently needed to control the pulmonary blood flow or pressures. OBJECTIVE: To report the efficacy of a new telemetric adjustable PAB (FloWatch-PAB) operated with the help of an external control unit that transmits to the implant energy and commands to further narrow or release the pulmonary artery using radiofrequency waves. METHODS AND RESULTS: In a multicenter, prospective, nonrandomized, single-arm clinical investigation, 13 children (median age, 4.5 months; range, 6 days to 11 years; median weight, 4.2 kg; range, 3.1 to 27 kg) underwent implantation of the FloWatch-PAB through median sternotomy in 8 and left thoracotomy in 5. The diagnosis was multiple ventricular septal (VSD) defects with complex anatomy in 3, single ventricle without pulmonary stenosis in 2, VSD with elevated pulmonary vascular resistance (PVR) in 2, atrio-ventricular canal (AVC) with elevated pulmonary vascular resistance in 1, AVC with diminutive right ventricle in 1, complex transposition of the great arteries in 3, and pulmonary atresia with complex pulmonary arteries anatomy in 1. All patients had normosystemic systolic pulmonary artery pressure. Additional procedures were performed in 7: atrial septectomy in 2, double aortic arch division in 1, patent ductus arteriosus ligation in 2, and coarctation repair in 2. There were no early or late deaths or device-related complications in a mean follow-up of 24 weeks (range, 18 to 42 weeks). A mean of 5.8 telemetric regulations per patient using the FloWatch-PAB were required to adjust the tightening of the PAB to the clinical needs (narrowing 74%, releasing 26%). At last follow-up, systolic pulmonary artery pressure was within normal range in all patients but 1. Systemic oxygen saturation demonstrated optimal regulation of the pulmonary blood flow in all according to each specific defect. Four patients were successfully corrected (VSD closure, AVSD repair, and 2 arterial switches with VSD closure). The device was easily removed and the pulmonary artery re-expanded spontaneously. CONCLUSIONS: This new device is safe and allows optimal adjustment of PAB in complex heart defects. In children requiring PAB, the use of this technology can obviate the need for early re-operations and appears to be a valuable option in the panel of surgical alternatives for selected infants.

Anthropometry↗
PubMed2004

Doppler-guided regulation of a telemetrically operated adjustable pulmonary banding system.

OBJECTIVES: We report on the Doppler-assessed regulation of an adjustable pulmonary artery band (PAB) in an animal model and in our first group of patients. BACKGROUND: Indications for pulmonary artery banding have expanded to include patients requiring a late arterial switch. A telemetry-operated, fully implantable, adjustable PAB system (FloWatch- PAB, Endoart SA, Lausanne, Switzerland) has been developed to facilitate these operations. METHODS: The device was implanted in 13 minipigs (age one to five months, weights 3.2 to 12.0 kg). The main study was performed on nine minipigs with adjustments of the PAB at implantation and at 1, 3, 5, 8, and 12 weeks after, assessed by Doppler pressure gradients. Explanation was performed 12 weeks after surgery. A long-term histology study (6 months and 14 months after surgery) was done on the other four minipigs. After approval by the ethics committee, the device was implanted in eight patients with weights between 2.8 and 9 kg to decrease pulmonary blood flow and pressure and to retrain the left ventricle before arterial switch. The device was progressively tightened, with increasing transband Doppler gradients. Follow-up was one to three months. RESULTS: An excellent correlation between transbanding systolic pressure gradient and degree of PAB constriction was encountered in the minipig study as well as in the human setting. No early or late deaths or reoperations occurred. Malfunction of the device was noted in three of 21 implanted devices. Two were related to surgically inflicted damage at implantation and one to an electronic problem that was fixed by resetting the control device. CONCLUSIONS: The device offers a Doppler-controllable adjustment of pulmonary blood flow. It permits controlled tightening and release of the band, which improves perioperative and postoperative courses and decreases surgical interventions to adjust tightness of the band. It allows a protracted occlusion protocol, which may provide the best effect on retraining the left ventricle.

Animals↗
PubMed2004

Bovine valved xenograft in pulmonary position: medium-term follow-up with excellent hemodynamics and freedom from calcification.

BACKGROUND: This study was designed to evaluate the outcome of Contegra xenograft valved conduit (Contegra, Medtronic Inc, Minneapolis, MN). METHODS: From April 1999 to December 2003, 67 patients with a mean age of 16.1 +/-15.0 years (2 months to 53 years) and a mean weight of 39.7 +/- 27.1 kg (4 to 95 kg) were discharged after implantation of a Contegra conduit. The diagnosis contained the following: pulmonary valve replacement during Ross operation (n = 27), pulmonary valve regurgitation (n = 9), tetralogy of Fallot (n = 7), pulmonary atresia with ventricular septal defect (n = 7), double outlet right ventricle (n = 7), truncus arteriosus (n = 5), Taussig-Bing (n = 2), obstructed conduit (n = 2), and double discordance (n = 1). Conduit size was 14 mm in 2, 16 mm in 7, 18 mm in 12, 20 mm in 13, and 22 mm in 33 patients. Mean cardiopulmonary bypass was 155 +/- 48 min (65 to 337 min) and mean aortic cross clamping was 69 +/- 38 min (0 to 146 min). All patients underwent echocardiography, 23 of 67 (34%) patients had cardiac catheterization, and 23 of 67 (34%) patients had electrocardiograph-gated multislice computer tomography. RESULTS: In a mean follow-up of 26.4 months (1 to 56 months) there was one late death (1 of 67 patients; 1.5% mortality) unrelated to the conduit. Five patients underwent reoperation; four were nonconduit-related and one was to replace a twisted conduit. Five patients underwent interventional cardiology; three were nonconduit-related and two were to stent a twisted or stenotic conduit. Echocardiography showed absent valve regurgitation in 30 of 67 (45%) patients, trivial in 21 of 67 (31%) patients, mild in 16 of 67 (24%) patients. The transconduit pressure gradient remained stable during follow-up, with peak pressure gradient 17 +/- 11 mm Hg and mean gradient 8 +/- 6 mm Hg. Internal diameters corresponded to 110% +/- 20% of the implanted diameter at level of proximal anastomosis, 112% +/- 18% at valve level, and 110% +/- 14% at distal anastomosis. Calcifications were not found, with the exception of a minimal (2.3 mm) parietal calcification. CONCLUSIONS: The Contegra valved conduit provided excellent morphology and hemodynamics, and freedom from calcification in a medium-term follow-up.

Adolescent↗
PubMed2004

Myocardial and pulmonary effects of aqueous oxygen with acute hypoxia.

BACKGROUND: The purpose of this paper was to evaluate myocardial and pulmonary effects of aqueous oxygen (AO) delivered directly into the pulmonary circulation in acute hypoxia. METHODS: Six calves (2 months old, 68.0 +/- 2.2 kg) after general anesthesia, mechanical ventilation, and median sternotomy underwent total right heart bypass using fixed flow with continuous pressure and blood gas measurements in carotid and femoral arteries, left atrium, the coronary sinus and PA. Measurements of systemic and PA pressures and O2 saturations; myocardial O2 atrioventricular (AV) differences; and O2 extraction were made. After base line measurements, hypoxic ventilation reducing the mean arterial PO2 from 277 +/- 102 mm Hg to 47 +/- 4 mm Hg (p < 0.0005) was maintained for 30 minutes. Without changes in the hypoxic ventilation (mean arterial PO2 = 49 +/- 11 mm Hg) 3 ml/min of hyperbaric aqueous oxygen (AO = oxygen diluted in saline solution) was administered into the PA for 30 minutes. Pulmonary blood flow was maintained during the entire experiment (3.7 +/- 0.3 L/min). RESULTS: Hypoxic ventilation significantly raised (p < 0.05) the systolic (30 +/- 7 vs 21 +/- 4 mm Hg), diastolic (20 +/- 6 vs 12 +/- 3 mm Hg), and mean (23 +/- 7 vs 15 +/- 3 mm Hg) PA pressure; PA/systemic pressure ratio for systolic (0.37 +/- 0.08 vs 0.25 +/- 0.06) and mean (0.56 +/- 0.19 vs 0.29 +/- 0.11) pressures; and pulmonary vascular resistance (PVR) (5.63 +/- 1.06 vs 3.53 +/- 0.75 U). Aqueous oxygen (AO) infusion significantly reduced (p < 0.05) the values obtained with hypoxic ventilation; systolic (23 +/- 5 vs 30 +/- 7 mm Hg), diastolic (11 +/- 4 vs 20 +/- 6 mm Hg), and mean (14 +/- 3 vs 23 +/- 7 mm Hg) PA pressure; PA/systemic pressure ratio for systolic (0.25 +/- 0.05 vs 0.37 +/- 0.08) and mean pressures (0.29 +/- 0.12 vs 0.56 +/- 0.19); and PVR (3.41 +/- 1.01 vs 5.63 +/- 1.06 U). AO infusion in the pulmonary circulation did not influence the myocardial O2 atrioventricular (AV) difference or the O2 extraction. CONCLUSIONS: Infusion of hyperbaric AO solution into the PA can completely reverse the negative effects of acute hypoxia on the pulmonary circulation without affecting the myocardial metabolism.

Animals↗
PubMed2004

Do valved stents compromise coronary flow?

OBJECTIVE: The aim of the present study is to evaluate a new self-expanding valved stent design for minimal invasive aortic valve implantation and its interference with coronary flow. METHODS: An equine pericardial valve mounted onto a self-expanding nitinol stent (3F Therapeutics trade mark, CA, USA), outer diameter 23 mm, was evaluated (A) in vitro in a dynamic pulsatile mock loop and (B) in vivo in six calves (75+/-2.5 kg). In four animals valve stents were implanted on-pump and in two animals off-pump after induction of ventricular fibrillation. Target site for deployment was the orthotopic aorta, over the native valves. In vivo assessment was performed with intracardiac (AcuNav) and intravascular ultrasound including leaflet motion, planimetric valve orifice and residual-coronary\sinus-stent-index (RCSSI, distance stent to aortic wall/coronary diameter) calculations, coronary blood flow characteristics, transvalvular gradient, regurgitation and paravalvular leaking, in combination with continuous cardiac output measures. Macroscopic analysis was performed at necropsy. RESULTS: Two-dimensional intracardiac ultrasound showed good leaflet motion, with full valvular opening and closing in five of six valves. Planimetric valve orifice was 1.75+/-0.4 cm(2). There were no signs of coronary flow impairment with an RCSSI of 1.8+/-1.2. The implanted valved stents showed a low transvalvular gradient of 5.3+/-3.9 mmHg (mean, peak-to-peak) on invasive measurements and 4.7+/-2.5 mmHg in two-dimensional intracardiac sonography. One of six valves showed mild to moderate regurgitation and one of six valves a minor to moderate paravalvular leak due to size mismatch. CONCLUSIONS: This new self-expanding valved stent design allows for on- and off-pump aortic valve implantation in the orthotopic aorta, over the native valves without interference of the coronary blood flow and excellent acute valve function in properly sized devices.

Animals↗