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Balloon angioplasty in the treatment of pulmonary valve stenosis and coarctation of the aorta.

When balloon angioplasty of the pulmonary valve was attempted in 42 children, aged 1 day to 19 years (mean, 3.1 years), immediate relief of pulmonary stenosis was achieved in 37 cases. In two groups, angioplasty was not uniformly successful: these included (1) two neonates and (2) three out of seven children with dysplastic pulmonary valves, who had an unsuccessful early result. Long-term (>1-year) follow-up of 28 successful cases supports the contention that balloon angioplasty provides effective long-term relief of pulmonary valve stenosis and that it should be considered the treatment of choice for this lesion. The results of angioplasty were also studied in 36 children who underwent this procedure to treat coarctation of the aorta (involving 21 native and 15 recurrent lesions). Angioplasty effectively relieved the obstruction in 30 cases (17 native and 13 recurrent lesions). In the six unsuccessful cases, poor hemodynamic results were due to age (three failures occurred in children less than 2 years old), tubular hypoplasia of the aorta (in one case), and the use of an undersized angioplasty balloon (in four cases, the diameter of the balloon was > or =3 mm less than that of the aortic isthmus). The 36 patients had two major complications: A cerebral vascular accident occurred in one case, and a late aortic aneurysm developed in another. Our results indicate that angioplasty is an effective form of therapy for most cases of coarctation of the aorta (whether native or recurrent).

Journal Article↗

Unilateral absence of a pulmonary artery in absent pulmonary valve syndrome: a case report and review of literature.

A six-year-old boy presented to the Cardiology clinic with history of mild cyanosis and dyspnea on exertion from age 1. He had a to-and-fro murmur at the middle left sternal border. Chest examination was normal but chest x-ray showed a small left lung. Echocardiography established the diagnosis of tetralogy of Fallot (TOF) and absent pulmonary valve with severe pulmonary regurgitation and moderate stenosis at the pulmonary valve site. There was severe dilatation of the main and right pulmonary arteries. The left pulmonary artery (LPA) could not be seen. Angiography failed to show a LPA. This case of an absent LPA associated with absent pulmonary valve syndrome is discussed and the literature is reviewed.

Abnormalities, Multiple↗

Percutaneous stent-mounted valve for treatment of aortic or pulmonary valve disease.

The objective of this study was to develop a prosthetic cardiac valve designed for percutaneous transcatheter implantation. Percutaneous catheter-based therapies play a limited role in the management of cardiac valve disease. Surgical implantation of prosthetic valves usually requires thoracotomy and cardiopulmonary bypass. The stent-valve is constructed of a rolled sheet of heat-treated nitinol. Although malleable when cooled, once released from a restraining sheath at body temperature the stent unrolls, becomes rigid, and assumes its predetermined cylindrical conformation. A ratcheting lock-out mechanism prevents recoil and external protrusions facilitate anchoring. Valve leaflets are constructed of bovine pericardium. The feasibility of catheter implantation, prosthetic valve function, and survival were investigated in an animal model. In vitro and pulse duplicator testing documented valve durability. Endovascular delivery of the prototype stent-valve to the aortic or pulmonary position was feasible. Accurate positioning was required to ensure exclusion of the native valve leaflets and, in the case of the aortic valve, to avoid compromise of the coronary ostia or mitral apparatus. Oversizing of the stent in relation to the valve annulus was desirable to facilitate anchoring and prevent paravalvular insufficiency. Stent-valve implantation proved feasible and compatible with survival in an animal model. Transcatheter implantation of prosthetic valves is possible. Further evolution of this technology will involve lower-profile devices with design features that facilitate vascular delivery, visualization, positioning, deployment, and valvular function.

Animals↗

Visceral leishmaniasis complicated by fungal pulmonary valve endocarditis.

We present a rare neglected case of fungal pulmonary valve endocarditis which presented with typical extra cardiac manifestations after repeated injections for treatment of visceral leishmaniasis. Surgical intervention to replace the pulmonary valve was the only option to manage the patient in spite of extensive medical treatment.

Adolescent↗

Changes in 99mTechnegas ventilation lung scan in a newborn with absent pulmonary valve syndrome.

A newborn infant with tetralogy of Fallot and absent pulmonary valve was successfully corrected in two stages. Absent pulmonary valve syndrome presenting in early infancy manifests severe respiratory symptoms that still make challenging both management and surgical treatment. This is ascribed to tracheobronchial compression by the extremely dilated pulmonary arteries, and to the resultant pulmonary obstructive lesions. We report herein the first findings of 99mTechnegas ventilation lung scanning in an infant with the syndrome to assess the pulmonary obstructive lesions.

Graphite↗

"Absent" pulmonary valve with atrial septal defect and patent ductus arteriosus.

The case of a newborn with "absent pulmonary valve," atrial septal defect, and patent ductus arteriosus is reported. He underwent surgical repair at five weeks of age, with closure of the patent ductus arteriosus and porcine pulmonary valve insertion. The clinical course leads us to suggest that reduction of pulmonary artery pressure and pulmonary valve competence will lead to prompt improvement in tracheobronchial compression and respiratory symptoms; no pulmonary arterioplasty is needed.

Abnormalities, Multiple↗

[Percutaneous pulmonary valve replacement: towards a modification of the prosthesis].

Percutaneous pulmonary valve replacement has recently been introduced as an alternative to surgery, pushing back the frontiers of interventional catheterisation. The authors report their experience in this field and focus on the complications of the method. From September 2000 to November 2002, 14 patients with a failing artificial pulmonary outflow tract were included in this protocol of clinical research. The authors attempted pulmonary implantation of a bovine jugular vein valve fitted in a vascular stent under general anaesthesia. The implantation was possible in all patients. Three had dynamic obstruction due to the implanted valve. This was due to infiltration of blood between the valve and the stent. The problem was resolved by: implanting a second valve in one patient: redialating the valve stent in two other patients. However, the last patient had to be reoperated 7 weeks after the implantation because of recurrence of the obstruction. One valve had to be explanted one year after implantation because of severe infectious endocarditis after unprotected dental treatment. Two patients experienced fracture of the stent but without valve dysfunction. Despite these complications, the clinical state of all patients improved during follow-up. The authors conclude that non-surgical pulmonary valve replacement is feasible, thereby increasing the therapeutic arsenal of interventional catheterisation. Simple modifications should result in fewer problems of dynamic obstruction and stent fracture, and lead to proposing this technique for native pulmonary outflow tracts.

Adolescent↗

[Mild pulmonary valve stenosis: the possible spontaneous cure in the natural history of the defect].

OBJECTIVE: To determine the long-term natural history of patients with mild pulmonary valve stenosis. METHODS: Throughout a 24-year evolutive period (1980 to 2004), 83 patients with pulmonary valve stenosis were evaluated, with 29 of them presenting a mild form of the defect. Of these 29, 13 patients had a long-term follow up. The mean age at the first and last follow-up visits was 34 months (1 month to 15 years) and 10.5 years (3 to 24 years), respectively. In addition to evolutive elements, those regarding clinical, electrocardiographic and echocardiographic aspects were also assessed. RESULTS: All patients remained asymptomatic throughout the study. Regarding the pulmonary valve pressure gradient, 5 (38.4%) presented a decrease, 3 (23%) remained unchanged, 4 (30.7%) presented elimination and 1 (7.6%) presented accentuation to a moderate degree of involvement. The mean initial and final gradient was 24.2 mmHg (15-30) and 13.6 mmHg (0-54), respectively. The initial gradients of the 4 patients who achieved spontaneous cure were 30, 19, 30 and 20 mmHg. The systolic murmur and right ventricular overload had a direct correlation to the gradient pressure degree, subdivided at each 10 mmHg. CONCLUSION: The spontaneous cure of the mild pulmonary valve stenosis is possible to achieve, similarly to other acyanogenic anomalies.

Adolescent↗

Percutaneous pulmonary valve replacement in a large right ventricular outflow tract: an experimental study.

OBJECTIVES: We report our initial experience with percutaneous pulmonary valve replacement in animals with large pulmonary trunks, using a modified percutaneous approach. BACKGROUND: Percutaneous pulmonary valve replacement has recently been introduced, and early clinical experience has been reported. This technique is presently limited to patients with a right ventricular outflow tract no bigger than 22 mm in diameter. METHODS: In seven animals (groups 1 and 3), we implanted a newly designed nitinol stent in the shape of a conduit with a central restriction of its diameter, containing an 18-mm bovine valve, as a one-step procedure. The animals in groups 1 and 3 were sacrificed after valve implantation and after two-month follow-up, respectively. In the second group (n = 3), we expected to percutaneously reduce the diameter of the pulmonary artery. Eight weeks later, we implanted an 18-mm valve mounted in a balloon-expandable stent. These animals were sacrificed after valve implantation. RESULTS: Eight of 10 devices were successfully delivered and were functioning perfectly at the initial evaluation and after two months. We failed to cross the tricuspid valve in two cases. The downsize mechanism allowed the pulmonary diameter to be reduced from 30 to 18 mm, without an impact on right ventricular function in any of the animals. CONCLUSIONS: Non-surgical implantation of a pulmonary valve is possible in ewes with all types of pulmonary trunk, regardless of its size. A "downsize" stent is needed to allow valve implantation in a large trunk. Further refinements will make this technique feasible in humans.

Animals↗

Absent pulmonary valve syndrome with interrupted aortic arch.

A surgically treated case of absent pulmonary valve syndrome associated with type B interrupted aortic arch is presented. The presence of a restrictive ductus arteriosus promoted the development of a collateral circulation between ascending and descending thoracic aorta, allowing the child to remain clinically stable after birth.

Aorta, Thoracic↗

Presystolic pulmonary valve opening in constrictive pericarditis.

Right heart pressure tracings were studied in 5 cases with constrictive pericarditis. The pressure of the A-wave in the right atrium of these cases was higher than the pulmonary arterial diastolic pressure. In addition, a presystolic wave appeared in the pulmonary arterial and the right ventricular pressure tracings, in coincidence with atrial systole. The pressure of this presystolic wave was similar to that of the right atrial A-wave. This suggests that the pulmonary valve opens following atrial systole, and then the blood flows into the pulmonary artery in the presystolic phase in patients with constrictive pericarditis. In 2 cases, pulmonary valve echograms were recorded. The a-dip in these 2 cases was as deep as 8.4 mm and 9.6 mm (1.8-4.1 mm with a mean of 2.80 mm for normal men), and its duration was prolonged to 0.17 sec and 0.18 sec (0.10-0.13 sec with a mean of 0.115 sec for normal men). In conclusion, such a deep and prolonged a-dip on pulmonary valve echogram is presumably a sign of presystolic pulmonary valve opening.

Adult↗

Indications and timing of pulmonary valve replacement after tetralogy of Fallot repair.

Surgical management of tetralogy of Fallot results in anatomic and functional abnormalities in the majority of patients. Although right ventricular volume load due to severe pulmonary regurgitation can be tolerated for years, there is now evidence that the compensatory mechanisms of the right ventricular myocardium ultimately fail and that if the volume load is not eliminated or reduced the dysfunction might be irreversible. In light of that data and with better understanding of risk factors for adverse outcomes late after tetralogy of Fallot repair, many centers are now recommending early pulmonary valve replacement before symptoms of heart failure develop. This article reviews the pathophysiology of chronic right ventricular volume load after tetralogy of Fallot repair and the risks and benefits of pulmonary valve replacement. Finally, recommendations for timing and indications for pulmonary valve replacement are given.

Adolescent↗

Magnetic resonance imaging of absent pulmonary valve syndrome.

A neonate with absent pulmonary valve syndrome was examined by means of echocardiography and magnetic resonance imaging (MRI). MRI provided an excellent evaluation of the intracardial morphology, vessel anatomy, mediastinal structures, and shunt flow; and it was superior to echocardiography for detection of aortopulmonary collaterals and vessel abnormalities. This case report of an uncommon cardiac abnormality confirms that MRI is a useful complementary modality to echocardiography in neonates and is recommended for problems with central pulmonary vessels and their relation to tracheobronchial structures.

Echocardiography↗

Restoration of the pulmonary valve reduces right ventricular volume overload after previous repair of tetralogy of Fallot.

BACKGROUND: Severe pulmonary regurgitation (PR) and associated right ventricular (RV) dilatation are late complications of surgical repair of tetralogy of Fallot (TOF). For the past several years, we have restored pulmonary valve competence with the exclusive use of cryopreserved allografts. METHODS AND RESULTS: Sixteen patients with symptoms of diminished exercise tolerance and echocardiographic evidence of progressive PR with severe RV dilatation underwent placement of allografts in the RV outflow tract at a median age of 12 years (10 years after TOF repair). Abnormal exercise tolerance tests were documented in 10 patients. Additional surgical procedures included pulmonary artery augmentation (n = 6), closure of residual left to right shunts (n = 3), and subendocardial resection for monomorphic ventricular tachycardia (n = 1). Six patients had either preoperative or postoperative balloon dilations of pulmonary artery stenoses. All patients had symptomatic improvement after allograft insertion. At a mean follow-up of 26.4 +/- 3.4 months, the severity of PR improved in all but one patient. In 12 patients (group 1), conduit regurgitation was either trace (n = 11) or mild (n = 1). Four patients (group 2) had moderate conduit regurgitation. In a retrospective analysis, pulmonary artery diameters and cross-sectional areas were significantly smaller in the group 2 patients compared with the group 1 patients. With the exception of one patient, RV end-diastolic diameter (RVEDD/BSA) fell after allograft insertion in each patient (P < .01). The reduction in RVEDD/BSA was significantly greater in group 1 than in group 2 (31.8 +/- 3.4% versus 21.4 +/- 11.0%, P < .05). CONCLUSIONS: Thus, restoration of the pulmonary valve with cryopreserved allografts improved exercise tolerance and diminished RV volume overload in patients with severe PR after previous repair of TOF. Optimal results were achieved in patients who did not have significant residual pulmonary artery distortion.

Child↗

Angiographic features associated with percutaneous balloon valvotomy for pulmonary valve stenosis.

Changes in the mobility of the pulmonary valve were determined by a retrospective review of right ventricular cineangiograms from 25 balloon pulmonary valvotomy (BV) procedures in 23 infants and children. The angiographic changes were compared with the post-BV catheter and Doppler pressure gradients across the right ventricular outflow tract. Angiographic features felt to indicate valve tearing were present following 17 of 25 procedures and included increased excursion or straightening of leaflets, localized change in leaflet motion (flail leaflet), and the presence of an additional contrast jet through the valve. There was no statistically significant relationship between any of the angiographic parameters and the pressure data. Most patients with marked increase in angiographic valve mobility had low residual right ventricular to pulmonary artery gradients. However, the absence of angiographic change was not always associated with a high residual gradient.

Catheterization↗

Left and right ventricular function in fetal tetralogy of Fallot with absent pulmonary valve.

Tetralogy of Fallot with absent pulmonary valve (TOF/APV) is a rare form of congenital heart disease with a high risk of perinatal mortality, particularly when diagnosed before birth. We aimed to assess whether global left and right ventricular function in fetal TOF/APV, using the Tei index, correlate with outcome. We reviewed the fetal echocardiogram and clinical outcome of eight fetuses diagnosed with TOF/APV. Of the eight cases, four developed cardiovascular compromise, leading to intrauterine death in two fetuses and neonatal demise in two fetuses, and four fetuses survived the neonatal period. The right ventricular (RV) Tei index was significantly greater and the left ventricular (LV) Tei index tended to be greater in nonsurvivors compared with survivors with TOF/APV (RV Tei, 0.90 +/- 0.17 versus 0.30 +/- 0.28, p < 0.05; LV Tei, 0.97 +/- 0.42 versus 0.54 +/- 0.21). The global LV and RV function can be affected in TOF/APV. Furthermore, more severe pulmonary insufficiency and worse biventricular function as assessed by Tei index likely contribute to the high perinatal mortality associated with this disease.

Dilatation, Pathologic↗

[Hemodynamic aspect of infundibular hypertrophy of pulmonary valve stenosis].

Reactional infundibular hypertrophy in pulmonary valve stenosis is usually assessed on the catheterization curves obtained in the infundibulum and in the inflow tract of the right ventricle. It is usually indicated by a peculiar pattern of the infundibular curve: its descending branch is more rapid than in the inflow tract and is slightly curvilinear. This deformity is the more marked the more intense the hypertrophy. Simultaneously a mid-late systolic murmur is recorded into the infundibulum the more intense and high-pitched the more marked the hypertrophy. Comparison with the angiocardiographic data and the operative findings showed a good correlation.

Angiocardiography↗

The influence of geometric mismatch between the native aortic, native pulmonary and homograft pulmonary valve on the results of the pulmonary autograft operation.

BACKGROUND: The pulmonary autograft operation has achieved broad acceptance and may be the ideal aortic valve substitute. Both the pulmonary autograft and the aortic homograft are more complicated procedures than prosthetic valve replacement. The trend to insert the pulmonary autograft as a root replacement rather than in the subcoronary position has achieved greater uniformity in the results, but there is still confusing diversity in opinions on technical details and anatomical dimensions. The importance of both size and shape mismatches between the three valves involved has received little attention. The valves often differ in diameter and in the shape of the recipient aortic annulus. This uncertainty and the diversity of opinions on essential technical details was disconcerting when we proceeded from aortic homograft-to-pulmonary autograft operations, this was compounded by only a single homograft being available for every operation as we have no homograft bank. METHODS: We compared the hemodynamic results regarding various geometric mismatches. All operative details were the same and patients were studied at regular intervals. Comparisons were made in patients with mismatch between recipient aortic annulus and pulmonary autograft. Patients with a normal tricuspid aortic annulus were compared to those with either a circular redo prosthetic valve annulus or a bicuspid recipient annulus. Thirdly we compared the patients with plication of the aortic annulus to those with remodeling of the distal aorta. Lastly we compared mismatch between donor homograft and pulmonary autograft. RESULTS: No influence of geometric mismatch between the three valves could be found on the results of the pulmonary autograft operation. CONCLUSIONS: Good results are obtainable without a painful learning curve if one keeps to certain surgical principles. It need not be a complicated operation and geometric mismatches between the three valves involved may be compensated for adequately.

Adolescent↗