Transcatheter closure of large patent ductus arteriosus at high altitude with a novel nitinol device.

BACKGROUND: Patent ducti arteriosi (PDAs) are more frequent and larger at high altitude than at sea level. A novel PDA closure device, the Nitocclud PDA-R, is designed specifically for both large and medium size PDAs. The initial clinical experience with a new nitinol-based device in high altitude patients with large PDAs is described. METHODS: The Nitocclud PDA-R is a self-expandable, self-centering, repositionable occluder made of one nitinol wire without use of welding. It contains several polyester membranes, is delivered with a central guide wire and is released by retraction of the central wire into the delivery catheter. The efficacy of this device was evaluated at several high altitude centers. RESULTS: Fifty-one patients without other congenital cardiac defects underwent transcatheter closure of PDA. Complete occlusion of the PDA was achieved in 98% of the patients. Nearly 49% of the patients had no shunt immediately after device implantation. Echocardiography revealed a complete closure rate by Doppler interrogation of 69% after 24 hr, 96% after 6 months, and 98% after 1 year. In two cases, device embolization was observed after release, and in both cases the device was easily retrieved with standard interventional techniques. There have been no episodes of delayed device migration, endocarditis, hemolysis, wire fracture, device disruption, or death. CONCLUSIONS: The Nitocclud PDA-R device is safe and effective and can easily close very large PDAs. This device has a high rate of complete occlusion within 1 year and is easily retrieved if embolized.

Chronic hypobaric hypoxia, patent arterial duct and a new interventional technique to close it.

BACKGROUND: Interventional closure of patent arterial duct has become an accepted alternative to surgical closure. Clinical trial with "Nit-Occlud® PDA-R". METHODS AND RESULTS: To assess the safety and efficacy of the device, we performed a prospective clinical study between June, 2009 and December, 2010 in La Paz, Bolivia. In all, 29 - 22 female patients and 7 male patients - out of 59 patients were selected on the basis of inclusion criteria. The procedures were performed under sedation at an age and weight of 5.7 years and 22.7 kilograms, respectively, with 4-6 French arterial sheaths and 5-7 French venous sheaths. The minimal diameter of the duct was 3.5 millimetres. The procedure, fluoroscopy, and hospitalisation times were 96.4 minutes (55 to 145), 13.1 minutes (3 to 25.2), and 24 hours, respectively. The "Nit-Occlud® PDA-R" was successfully deployed in all patients. Immediate, 24-hour, 1-, 3-, and 6-month closure rates were 65.5%, 79.3%, 96.5%, and 100%, respectively. The systolic pulmonary pressure diminished from 37 millimetres of mercury (21 to 57) before the intervention to 31 millimetres of mercury (21 to 45) after the intervention. No early or late embolisation, haemolysis, left pulmonary artery, or descending aorta obstruction occurred. CONCLUSIONS: We conclude that the "Nit-Occlud® PDA-R" device is safe and effective in closing patent arterial duct up to a diameter of 8 millimetres.

AntimiR-132 Attenuates Myocardial Hypertrophy in an Animal Model of Percutaneous Aortic Constriction.

BACKGROUND: Pathological cardiac hypertrophy is a result of afterload-increasing pathologies including untreated hypertension and aortic stenosis. It features progressive adverse cardiac remodeling, myocardial dysfunction, capillary rarefaction, and interstitial fibrosis often leading to heart failure. OBJECTIVES: This study aimed to establish a novel porcine model of pressure-overload-induced heart failure and to determine the effect of inhibition of microribonucleic acid 132 (miR-132) on heart failure development in this model. METHODS: This study developed a novel porcine model of percutaneous aortic constriction by implantation of a percutaneous reduction stent in the thoracic aorta, inducing progressive remodeling at day 56 (d56) after pressure-overload induction. In this study, an antisense oligonucleotide specifically inhibiting miR-132 (antimiR-132), was regionally applied via intracoronary injection at d0 (percutaneous transverse aortic constriction induction) and d28. RESULTS: At d56, antimiR-132 treatment diminished cardiomyocyte cross-sectional area (188.9 ± 2.8 vs. 258.4 ± 9.0 µm2 in untreated hypertrophic hearts) and improved global cardiac function (ejection fraction 48.9 ± 1.0% vs. 36.1 ± 1.7% in control hearts). Moreover, at d56 antimiR-132-treated hearts displayed less increase of interstitial fibrosis compared with sham-operated hearts (Δsham 1.8 ± 0.5%) than control hearts (Δsham 10.8 ± 0.6%). Of note, cardiac platelet and endothelial cell adhesion molecule 1+ capillary density was higher in the antimiR-132-treated hearts (647 ± 20 cells/mm2) compared with in the control group (485 ± 23 cells/mm2). CONCLUSIONS: The inhibition of miR-132 is a valid strategy in prevention of heart failure progression in hypertrophic heart disease and may be developed as a treatment for heart failure of nonischemic origin.

Preclinical evaluation of a new self-expanding device for closure of muscular ventricular septal defects in a pig model.

OBJECTIVES: Aim of our study was the preclinical evaluation of a new self expanding device for interventional closure of muscular ventricular septal defects (mVSDs) in an acute pig model. BACKGROUND: Devices currently in use for closure of mVSDs still have their limitations. The deployment of the disks is dependent from the expansion of the stent, which can be associated with problems for sufficient closure of the mVSDs. This was the reason for developing a modified device with only one disk MATERIALS AND METHODS: The device was constructed in a single wire technique with a unique configured retention disk. mVSDs were created in six pigs with a specially designed punch instrument, and subsequently closed with our new device during the same session using a jugular or femoral vein approach. Potential residual shunting volumes were estimated by echocardiography and hemodynamic measurements. After closure, animals were sacrificed, and hearts were harvested for macropathologic evaluation. In two animals, MRI was performed for additional noninvasive evaluation. RESULTS: Devices were successfully implanted in all animals with good alignment of the disk to the left ventricular septum, even if the stent was oversized. Echocardiography, hemodynamics, angiography and macropathology revealed complete closure of all mVSDs. MRI and echocardiography showed a good visibility of the device. CONCLUSIONS: Our preclinical study shows successful closure of iatrogenic created mVSDs without residual shunting. The device is characterized by a more controlled deployment, an independent deployment of disk and waist, and a good alignment of the left ventricular disk to the muscular septum.

Developing High Medical Technology, a Challenge for Developing Countries: The Percutaneous Closure of Atrial Septal Defects Using Nit-Occlud ASD-R: Early and Mid-term Results.

OBJECTIVE: To assess the efficacy and safety of the Nit-Occlud ASD-R (PFM S.R.L, La Paz, Bolivia) in the percutaneous closure of secundum atrial septal defects (ASD). PATIENTS AND METHODS: Fifty-three consecutive patients with median age of 11 years (range 3-67) and mean weight 27.1 kg (range 13-75 kg), treated in two cardiology centers between May 2007 and March 2011. RESULTS: Mean fluoroscopy time was 14 minutes (5-53), mean procedure time was 70 minutes (45-150), mean defect size, as measured by the stop-flow technique, was 17.8 mm (5.6-31), and mean stent size of the implanted device was 18 mm (6-28), which is 0.98 times the defect size. Successful closure of the ASD without major complications was achieved in 49 of 53 patients. In 71.4% of patients in whom device implantation was accomplished, there was no evidence of a persistent shunt at the completion of the procedure. This closure rate increased to 91.7% after 24 hours, with 95.8% closure after three months and 100% closure after six months. Device embolization occurred in one patient within 24 hours of implantation and required surgical device removal and ASD closure. There were no other major complications and no deaths during the period of follow-up (average 72 months; range 59-105 months). CONCLUSION: The Nit-Occlud ASD-R device is safe and effective with very good closure rates.

Magnetic resonance-guided placement of atrial septal closure device in animal model of patent foramen ovale.

BACKGROUND: Percutaneous closure of the patent foramen ovale (PFO) is usually performed under x-ray in combination with ultrasound guidance. We tested the feasibility of applying magnetic resonance (MR) guidance for percutaneous closure of PFO in an animal model, thus avoiding the disadvantage of ionizing radiation. METHODS AND RESULTS: Real-time MRI with radial or spiral k-space filling (15 frames per second) on an interventional 1.5-T high-field whole-body system was exploited to examine the feasibility of MR-guided closure of the PFO in 7 piglets weighing approximately 14 kg. A specially designed prototype nonmagnetic closure device was introduced via the femoral vein. The short bore of the magnet and in-room monitors allowed for visualization and steering of the catheter with the loaded occluder. Catheterization of the left atrium and, finally, correct placement of the device was possible in all animals. Deployment of the device was depicted by real-time MR, and initial misplacement, which occurred in 2 animals, was easily detected and corrected. CONCLUSIONS: Real-time MR guidance of PFO closure, without the use of ionizing radiation, is feasible in an animal model.

Bacterial nanocellulose as a new patch material for closure of ventricular septal defects in a pig model.

OBJECTIVES: Current materials for closure of cardiac defects such as ventricular septal defects (VSDs) are associated with compliance mismatch and a chronic inflammatory response. Bacterial nanocellulose (BNC) is a non-degradable biomaterial with promising properties such as high mechanical strength, favourable elasticity and a negligible inflammatory reaction. The aim of this study was the evaluation of a BNC patch for VSD closure and the investigation of its in vivo biocompatibility in a chronic pig model. METHODS: Young's modulus and tensile strength of BNC patches were determined before and after blood exposure. Muscular VSDs were created and closed with a BNC patch on the beating heart in an in vivo pig model. Hearts were explanted after 7, 30 or 90 days. Macropathology, histology and immunohistochemistry were performed. RESULTS: Young's modulus and tensile strength of the BNC patch decreased after blood contact from 6.3 ± 1.9 to 3.86 ± 2.2 MPa (P < 0.01) and 0.33 ± 0.06 to 0.26 ± 0.06 MPa (P < 0.01), respectively, indicating the development of higher elasticity. Muscular VSDs were closed with a BNC patch without residual shunting. After 90 days, a mild chronic inflammatory reaction was present. Moreover, there was reduced tissue overgrowth in comparison with polyester. Proceeding cellular organization characterized by fibromuscular cells, production of extracellular matrix, neoangiogenesis and complete neoendothelialization were found. There were no signs of thrombogenicity. CONCLUSIONS: BNC patches can close VSDs with good mid-term results and its biocompatibility can be considered as satisfactory. Its elasticity increases in the presence of blood, which might be advantageous. Therefore, it has potential to be used as an alternative patch material in congenital heart disease.

Repair of posterior mitral valve prolapse with a novel leaflet plication clip in an animal model.

OBJECTIVE: Recently, there has been increased interest in minimally invasive mitral valve prolapse repair techniques; however, these techniques have limitations. A new technique was developed for treating mitral valve prolapse that uses a novel leaflet plication clip to selectively plicate the prolapsed leaflet segment. The clip's efficacy was tested in an animal model. METHODS: Yorkshire pigs (n = 7) were placed on cardiopulmonary bypass (CPB), and mitral valve prolapse was created by cutting chordae supporting the P2 segment of the posterior leaflet. Animals were weaned off CPB and mitral regurgitation (MR) was assessed echocardiographically. CPB was reinitiated and the plication clip was applied under direct vision to the P2 segment to eliminate the prolapse. The animals survived for 2 hours. Epicardial echocardiography was obtained before and after prolapse creation and 2 hours after clip placement to quantify MR grade and vena contracta area. Posterior leaflet mobility and coaptation height were analyzed before and after clip placement. RESULTS: There were no cases of clip embolization. Median MR grade increased from trivial (0-1.5) to moderate-severe after MR creation (2.5-4+) (P < .05), and decreased to mild after clip placement (0-3+) (P < .05). Vena contracta area tended to increase after cutting the chordae and decrease after clip placement: 0.08 ± 0.10 cm(2) versus 0.21 ± 0.15 cm(2) versus 0.16 ± 0.16 cm(2) (P = .21). The plication clip did not impair leaflet mobility. Coaptation height was restored to baseline: 0.51 ± 0.07 cm versus 0.44 ± 0.18 cm (P = 1.0). CONCLUSIONS: The leaflet plication clip can treat mitral valve prolapse in an animal model, restoring coaptation height without affecting leaflet mobility. This approach is a simple technique that may improve the effectiveness of beating-heart and minimally invasive valve surgery.

A blood-resistant surgical glue for minimally invasive repair of vessels and heart defects.

Currently, there are no clinically approved surgical glues that are nontoxic, bind strongly to tissue, and work well within wet and highly dynamic environments within the body. This is especially relevant to minimally invasive surgery that is increasingly performed to reduce postoperative complications, recovery times, and patient discomfort. We describe the engineering of a bioinspired elastic and biocompatible hydrophobic light-activated adhesive (HLAA) that achieves a strong level of adhesion to wet tissue and is not compromised by preexposure to blood. The HLAA provided an on-demand hemostatic seal, within seconds of light application, when applied to high-pressure large blood vessels and cardiac wall defects in pigs. HLAA-coated patches attached to the interventricular septum in a beating porcine heart and resisted supraphysiologic pressures by remaining attached for 24 hours, which is relevant to intracardiac interventions in humans. The HLAA could be used for many cardiovascular and surgical applications, with immediate application in repair of vascular defects and surgical hemostasis.

Functional classification of pulmonary hypertension in children: Report from the PVRI pediatric taskforce, Panama 2011.

The members of the Pediatric Task Force of the Pulmonary Vascular Research Institute (PVRI) were aware of the need to develop a functional classification of pulmonary hypertension in children. The proposed classification follows the same pattern and uses the same criteria as the Dana Point pulmonary hypertension specific classification for adults. Modifications were necessary for children, since age, physical growth and maturation influences the way in which the functional effects of a disease are expressed. It is essential to encapsulate a child's clinical status, to make it possible to review progress with time as he/she grows up, as consistently and as objectively as possible. Particularly in younger children we sought to include objective indicators such as thriving, need for supplemental feeds and the record of school or nursery attendance. This helps monitor the clinical course of events and response to treatment over the years. It also facilitates the development of treatment algorithms for children. We present a consensus paper on a functional classification system for children with pulmonary hypertension, discussed at the Annual Meeting of the PVRI in Panama City, February 2011.

A consensus approach to the classification of pediatric pulmonary hypertensive vascular disease: Report from the PVRI Pediatric Taskforce, Panama 2011.

Current classifications of pulmonary hypertension have contributed a great deal to our understanding of pulmonary vascular disease, facilitated drug trials, and improved our understanding of congenital heart disease in adult survivors. However, these classifications are not applicable readily to pediatric disease. The classification system that we propose is based firmly in clinical practice. The specific aims of this new system are to improve diagnostic strategies, to promote appropriate clinical investigation, to improve our understanding of disease pathogenesis, physiology and epidemiology, and to guide the development of human disease models in laboratory and animal studies. It should be also an educational resource. We emphasize the concepts of perinatal maladaptation, maldevelopment and pulmonary hypoplasia as causative factors in pediatric pulmonary hypertension. We highlight the importance of genetic, chromosomal and multiple congenital malformation syndromes in the presentation of pediatric pulmonary hypertension. We divide pediatric pulmonary hypertensive vascular disease into 10 broad categories.

3-dimensional printing of models to create custom-made devices for coil embolization of an anastomotic leak after aortic arch replacement.

PURPOSE: The objective of this study was to show the use of 3-dimensional printing models to fabricate a custom-made occluder for device embolization of an anastomotic leak after replacement of the ascending aorta and the aortic arch in a human immunodeficiency virus (HIV)-infected patient. DESCRIPTION: We present a 50-year-old HIV-infected patient who underwent ascending aorta and aortic arch replacement for a type A dissection, and who had an aortic arch pseudoaneurysm (sized 5 x 5 x 4 cm) with a slit-shaped entrance hole located anteriorly to the implanted supra-aortic vessels. The patient's 128-slice computed tomography data were visualized and reconstructed. Afterward we fabricated a life-like replica of the complex pathology of the ascending aorta and the aortic arch using a rapid prototyping machine. After careful examination of the model, we fabricated a custom-made occluder device for interventional closure of the leakage. EVALUATION: Using data derived from 128-slid computed tomography linked to proprietary software, we were able to create models of the ascending aorta, the aortic arch end, especially the pseudoaneurysm with its slit-shaped opening between the aortic lumen and the aneurysm. This was very helpful to build a perfectly fitting custom-made occluder device to plan and simulate the interventional closure. Moreover, the models were helpful for intra-interventional orientation. CONCLUSIONS: The stereolithographic replicas were extremely useful for choosing the treatment option and for planning and simulating the occlusion of the pseudoaneurysm. Furthermore, the models were necessary for our engineers who were building the custom-made occluder device.

Evaluation of a new hybrid technique for closure of muscular ventricular septal defects in a long-term setting.

OBJECTIVE: Therapy for muscular ventricular septal defects beyond the moderator band, especially in neonates and infants, has always been challenging for both surgeons and cardiologists. Recently, we established a patch closure hybrid therapy for muscular ventricular septal defects. In this study, we evaluated it in a long-term porcine model. METHODS: Thirteen minipigs underwent anterolateral thoracotomy to expose the left ventricle. Muscular ventricular septal defects were created under 2- and 3-dimensional echocardiographic guidance with a 7.5-mm sharp punch instrument. Closure of the defects was undertaken with our new patch system in hybrid technique. Animals were observed for 3 months. Echocardiographic evaluation and pathologic examination, including immunohistochemical staining, were undertaken. RESULTS: Defects were successfully created in 12 pigs and closed in 10 pigs. Seven survived for 3 months. Residual shunting was noticed in 1 animal. Neither left ventricular dysfunction nor relevant damage to the valves could be detected. Pathologic examination showed complete endothelialization of the patch and the nitinol anchors without protruding parts of the system. Cellular organization was proceeding. Immunohistochemical staining demonstrated endothelial cells on the surface of the patch and fibromuscular cells around the patch. CONCLUSION: Our hybrid therapy was efficacious in closing muscular ventricular septal defects without impairment of cardiac function. The patch system and nitinol anchors demonstrated good integration into the septum. Further development of the system for human application is already being undertaken.

Beating-heart patch closure of muscular ventricular septal defects under real-time three-dimensional echocardiographic guidance: a preclinical study.

OBJECTIVES: Safe and effective device closure of ventricular septal defects remains a challenge. We have developed a transcardiac approach to close ventricular septal defects using a patch delivery and fixation system that can be secured under real-time three-dimensional echocardiographic guidance. METHODS: In Yorkshire pigs (n = 8) a coring device was introduced into the left ventricle through a purse-string suture placed on the left ventricular apex, and a muscular ventricular septal defect was created. The patch deployment device containing a 20-mm polyester patch was advanced toward the ventricular septal defect through another purse-string suture on the left ventricular apex, and the patch was deployed under real-time three-dimensional echocardiographic guidance. The anchor delivery device was then introduced into the left ventricle through the first purse-string suture. Nitinol anchors to attach the patch around the ventricular septal defect were deployed under real-time three-dimensional echocardiographic guidance. After patch attachment, residual shunts were sought by means of two-dimensional and three-dimensional color Doppler echocardiography. The heart was then excised, and the septum with the patch was inspected. RESULTS: A ventricular septal defect was created in the midventricular (n = 4), anterior (n = 2), and apical (n = 2) septum. The mean size was 9.8 mm (8.2-12.0 mm), as determined by means of two-dimensional color Doppler scanning. The ventricular septal defects were completely closed in 7 animals. In one a 2.4-mm residual shunt was identified. No anatomic structures were compromised. CONCLUSIONS: Beating-heart perventricular muscular ventricular septal defect closure without cardiopulmonary bypass can be successfully achieved by using a catheter-based patch delivery and fixation system under real-time three-dimensional echocardiographic guidance. This approach might be a better alternative to cardiac surgery or transcatheter device closure.

Patch closure of muscular ventricular septal defects with a new hybrid therapy in a pig model.

OBJECTIVES: We evaluated a novel technique for hybrid patch closure of muscular ventricular septal defects (mVSDs) without cardiopulmonary bypass (CPB) in a pig model. BACKGROUND: So far, surgical and interventional therapies for mVSDs have been associated with significant morbidity, especially in newborns and infants. Thus, it is essential to develop new techniques. Hybrid therapy is an innovative approach for mVSDs that combines the advantages of surgical and interventional techniques. METHODS: Six pigs underwent left anterolateral thoracotomy to expose the left ventricle (LV). The mVSDs were created under echocardiographic guidance with a 7.5-mm sharp punch instrument that was forwarded via an LV incision. A special designed patch system composed of a patch with a Nitinol frame was passed across the carotid artery into the LV and positioned in front of the mVSD. An instrument resembling a stapler was introduced across the LV wall on the beating heart without use of CPB. The patch was fixed with Nitinol anchors on the septum under echocardiographic and fluoroscopic guidance. Finally, the Nitinol frame was detached from the patch. RESULTS: The locations of the defects were apical (n = 1), midmuscular (n = 3), and anterior muscular (n = 2). Closure of the mVSD was successful in 5 of 6 animals confirmed by echocardiography, hemodynamic measurements, and explantation of the heart. Animals were hemodynamically stable throughout the experiment. CONCLUSIONS: Here, we present a novel technique for hybrid closure of mVSDs without use of CPB. Further development of the patch system is necessary to assess applicability in humans, especially for the target group of newborns and infants.

Clasificación funcional de la hipertensión pulmonar en niños: informe del task force pediátrico del Pulmonary Vascular Research Institute (PVRI), Panamá 2011 / Functional classification of pulmonary hypertension in children: Report from the PVRI pediatric taskforce, Panama 2011

Los miembros del Task Force pediátrico del Pulmonary Vascular Research Institute (PVRI, su sigla en Inglés) fueron conscientes de la necesidad de desarrollar una clasificación funcional de la hipertensión pulmonar en niños. La clasificación que se propone sigue el mismo patrón y utiliza los mismos criterios de la clasificación de la hipertensión pulmonar específica para adultos de Dana Point. Fue necesario incluir modificaciones para los niños, teniendo en cuenta que la edad, el crecimiento físico y la madurez influyen en la expresión funcional de la enfermedad. Es necesario definir el estado clínico del niño, pues ello facilita revisar la evolución del mismo en una forma consistente y objetiva a medida que él/ella crecen. Particularmente en los niños más jóvenes, se trató de incluir indicadores objetivos como el crecimiento, la necesidad de alimentos suplementarios y los registros de asistencia al colegio y a la guardería. Esto ayuda a monitorear la evolución clínica y la respuesta al tratamiento a través de los años y facilita el desarrollo de algoritmos de tratamiento en estos pacientes. Se presenta un artículo de consenso sobre una clasificación aplicable a los niños con hipertensión pulmonar que se discutió en la reunión anual del PVRI que se llevó a cabo en Panamá en febrero de 2011.

The members of the Pediatric Task Force of the Pulmonary Vascular Research Institute (PVRI) were aware of the need to develop a functional classification of pulmonary hypertension in children. The proposed classification follows the same pattern and uses the same criteria as the Dana Point pulmonary hypertension specific classification for adults. Modifications were necessary for children, since age, physical growth and maturation influences the way in which the functional effects of a disease are expressed. It is essential to encapsulate a child's clinical status, to make it possible to review progress with time as he/she grows up, as consistently and as objectively as possible. Particularly in younger children we sought to include objective indicators such as thriving, need for supplemental feeds and the record of school or nursery attendance. This helps monitor the clinical course of events and response to treatment over the years. It also facilitates the development of treatment algorithms for children. We present a consensus paper on a functional classification system for children with pulmonary hypertension, discussed at the Annual Meeting of the PVRI in Panama City, February 2011.

Consenso sobre la clasificación de la enfermedad vascular pulmonar hipertensiva en niños: reporte del task force pediátrico del Pulmonary Vascular Research Institute (PVRI) Panamá 2011 / A consensus approach to the classification of pediatric pulmonary hypertensive vascular disease: Report from the PVRI Pediatric Taskforce, Panama 2011

Las clasificaciones actuales de la hipertensión pulmonar han contribuido significativamente al conocimiento de la enfermedad vascular pulmonar, han facilitado ensayos farmacológicos y han mejorado nuestro conocimiento de las cardiopatías congénitas del adulto; sin embargo estas clasificaciones no son aplicables completamente a la enfermedad en el niño. La clasificación que aquí se propone se basa principalmente en la práctica clínica. Los objetivos específicos de esta nueva clasificación son mejorar las estrategias diagnósticas, promover la investigación clínica, mejorar nuestro conocimiento de la patogénesis, de la fisiología y de la epidemiología de la enfermedad y orientar el desarrollo de modelos de la enfermedad humana en el laboratorio y estudios en animales; también puede servir como un recurso docente. Se hace énfasis en los conceptos de maladaptación perinatal, alteraciones del desarrollo e hipoplasia pulmonar como factores causantes de la hipertensión pulmonar pediátrica; así mismo, en la importancia de los múltiples síndromes malformativos congénitos, genéticos y cromosómicos en la presentación de la hipertensión pulmonar pediátrica. La enfermedad vascular pulmonar hipertensiva en niños se divide en diez grandes categorías.

Current classifications of pulmonary hypertension have contributed a great deal to our understanding of pulmonary vascular disease, facilitated drug trials, and improved our understanding of congenital heart disease in adult survivors. However, these classifications are not applicable readily to pediatric disease. The classification system that we propose is based firmly in clinical practice. The specific aims of this new system are to improve diagnostic strategies, to promote appropriate clinical investigation, to improve our understanding of disease pathogenesis, physiology and epidemiology, and to guide the development of human disease models in laboratory and animal studies. It should be also an educational resource. We emphasize the concepts of perinatal maladaptation, maldevelopment and pulmonary hypoplasia as causative factors in pediatric pulmonary hypertension. We highlight the importance of genetic, chromosomal and multiple congenital malformation syndromes in the presentation of pediatric pulmonary hypertension. We divide pediatric pulmonary hypertensive vascular disease into 10 broad categories.

Three-dimensional echo and videocardioscopy-guided atrial septal defect closure.

BACKGROUND: Current real-time three-dimensional echocardiography systems (RT3DE) can provide sufficient visualization to permit atrial septal defect (ASD) closure. However, detailed visualization of small objects inside the heart is still suboptimal because of limited resolution, which is a limitation for clinical application. We evaluate the complementary use of videocardioscopy in image-guided ASD closure. METHODS: In a pig model (n = 5), a 4-mm to 8-mm ASD was created with RT3DE guidance. Defect closure was accomplished with a catheter-based patch-delivery system fixed around the defect with mini-anchors under combined RT3DE and videocardioscopy guidance. The endoscope was inserted into the heart through a custom built port designed to allow visualization in the presence of blood. RESULTS: All ASDs were successfully closed. The combination of RT3DE and videocardioscopy allowed detailed visualization of intracardiac structures, instruments, patch, and mini-anchors. CONCLUSIONS: Beating-heart ASD closure can be achieved with combined RT3DE and videocardioscopy imaging. Use of videocardioscopy provides high-resolution imaging and likely improves safety of the image-guided procedure.

Angioplastía percutánea en coartación aortica / Pecutaneous angiioplasty in aortic coarttation

Experiencia local en la técnica de angioplastía con catéter-balón, realizada en siete pacientes con edad que oscila entre 1 mes a 27 años, siendo 5 varones y 2 mujeres, con diagnostico de coartación aórtica nativa. Una vez realizada la sedación, se colocó un introductor en la arteria femoral y se procedió al avance de guías y catéteres hasta la aorta transversa, con el objetivo de obtener imágenes angiografícas y medir presiones invasivas en todos los segmentos. El gradiente de presión pre intervención fue de 41.5mmHg en promedio (rango:21-69mmHg) disminuyó post intervención a 10mmHg en promedio (rango:0-20mmHg). El diámetro de la coartación pre dilatación en promedio fue de 4.3mm (rango: 2.3 a 9.4mm) y aumentó post dilatación a 8.4 mm (rango: 5.5 a 13.5mm). El resultado final fue satisfactorio, pues disminuyó significativamente el gradiente de presión, el diámetro aórtico coartado aumentó y los pulsos en las cuatro extremidades se tornaron simétricos. Se alcanzó estabilidad clínica y el procedimiento se demostró como favorable en todos los pacientes. Los controles postintervención hasta un año después mostraron que el gradiente se mantiene en el tiempo, salvo en el caso de la niña de un mes, que desarrolló recoartación aórtica y fue operada en condiciones electivas, como es usual para este grupo de edad.

Local experience in the technique of balloon catheter angioplasty, performed in seven patients aged between 1 month and 27 years, 5 males and 2 females, diagnosed with native aortic coarctation. After the sedation, the introducer was collocated in the femoral artery, and guide wires and catheters were pushed forward until the transverse aorta in order to obtain angiographic images and to measure invasive pressures in all the segments. The mean pressure gradient before the intervention was 41.5mmHg (range:21-69mmHg) and decreased post intervention to 10mmHg (range:0-20mmHg). The mean diameter of the coarctation pre dilatation was 4.3mm (range:2.3-9.4mm) and increased post dilation to 8.4mm(range:5.5-13.5mm). The final result was satisfactory because the pressure gradient was significantly reduced, the aortic diameter increased and the pulses in all four extremities symmetrical. Clinical stability was achieved and the procedure proved to be favorable for all the patients. Controls until one year post intervention showed that the gradient did not change over the time, except in the case of a one month old girl, who developed recoarctation and was operated in elective conditions, as it is usual for this group of age.