Percutaneous closure of patent arterial ducts in patients from high altitude: a sub-Saharan experience.

BACKGROUND: At high altitude, patent arterial ducts tend to be larger and associated with pulmonary hypertension. Patent ductus arteriosus device closure in this background could be challenging. OBJECTIVES: We report our experience with percutaneous closure of patent arterial ducts using a variety of devices in patients residing in a high altitude. PATIENTS AND METHODS: This is a retrospective review of the case records of 145 patients (age 9 months-20 years, mean 5.6 ± 3.9 years, and weight 7-54 kg, mean 17.7 ± 9.4) with duct sizes ranging between 2 and 21 mm, (mean, 5.8 ± 2.7) who underwent percutaneous closure of patent arterial ducts. One hundred thirty-six (93.8%) of the patients were from a geographic area of 2100-2800 m above sea level. RESULTS: Successful device closure was achieved in 143 cases. It was difficult to achieve device stability in two patients with expansile ducts. Therefore, they were treated surgically. The devices used were various types of duct occluder devices in 131 patients, while atrial and ventricular septal occluders were used in eight patients. For the group, mean systolic pulmonary artery (PA) pressure decreased from 47.0 ± 16.7 mmHg before occlusion to 29.0 ± 7.4 mmHg after occlusion (P ≤ 0.001)., mean diastolic PA pressure from 25.0 ± 10.9 mmHg to 14.8 ± 6.0 mmHg and the average mean PA pressure decreased from 35.9 ± 13.5 mmHg to 21.1 ± 6.5 mmHg. Complications (4.8%) included device and coil embolization, bleeding, and pulse loss. On follow-up (mean duration of 36.1 ± 12.1 months, range 12-62 months), 137 patients were in functional class 1, 3 had residual shunt, 2 had device migration and one patient had persisting pulse loss. CONCLUSIONS: Successful duct closure was achieved in the vast majority of patients, even though the ducts were larger and significant number of them had pulmonary hypertension in this high altitude group. There was a relatively higher incidence of residual shunts and device migration in this series, generally due to the nonavailability of optimal device and surgical support. Long-term follow-up is required before we can draw conclusions with regard to the sustainability of drop in PA pressures. Septal Occluder devices may be a possible alternative for large tubular or window-type ducts with severe pulmonary hypertension, where there may be concerns about the size and stability of duct occluder devices.

Percutaneous balloon dilation of severe pulmonary valve stenosis in patients with cyanosis and congestive heart failure.

OBJECTIVES: This article reports outcomes of percutaneous balloon dilation in patients with severe pulmonary valve stenosis, in particular in those treated late with cyanosis, congestive heart failure, and pericardial effusion. BACKGROUND: Percutaneous balloon dilation is the treatment of choice for pulmonary valve stenosis. Although earlier intervention may produce better results, patients may present late with congestive heart failure and cyanosis. METHODS: Fifty-five patients who underwent pulmonary valve balloon dilation, were grouped into two groups, based on the presence or absence of congestive right heart failure and/or central cyanosis. Group I included 33 patients with severe pulmonary valve stenosis, but without clinical evidence of congestive right heart failure in the form of liver enlargement, raised jugular venous pressure, and peripheral edema and/or central cyanosis and group II included 22 patients with severe pulmonary valve stenosis and congestive right heart failure and/or central cyanosis. Their outcomes were compared. RESULTS: Doppler measured transvalvar pressure gradient decreased from 110.2 ± 34.0 mm Hg before to 52.5 ± 28.7 mm Hg in group I after dilation (P < 0.001), and from 138.4 ± 32.3 mm Hg to 53.9 ± 19.3 mm Hg in group II, (P < 0.001). Complications included ventricular tachycardia/fibrillation in three patients and severe bradycardia in one patient in group II. Twelve patients in group II developed clinical and radiologic evidence of reperfusion injury/pulmonary edema within the first 24 hr of intervention and needed ventilation for 2-9 days. Three of these patients died from intractable pulmonary edema. On follow up, clinical and echocardiographic improvement parameters were similar in the two groups. CONCLUSION: Those patients with severe pulmonary valve stenosis with congestive right heart failure, especially those with pericardial effusion, ascites and cyanosis, represent an important technical and clinical challenge. They are a high-risk group with or without treatment. If they survive the procedure, they may still remain at a high risk in the first few days afterward. Maintaining their ventilator and inotropic support after balloon dilation may increase survival. However, excellent results can be obtained.

Discrete subpulmonic membrane in association with isolated severe pulmonary valvar stenosis.

BACKGROUND: Subpulmonic membrane as a cause of right ventricular outflow tract obstruction in patients with concordant ventriculoarterial connection and intact ventricular septum is considered to be rare. CASE PRESENTATION: A 7-year-old boy was referred to a tertiary care hospital with complaints of dyspnea on moderate exertion and palpitations of about 2 years duration. Physical examination revealed parasternal lift, systolic thrill and a 4/6 ejection systolic murmur, best heard over the left 2nd intercostal space. His oxygen saturation was 88% on room air. Two-dimensional echocardiography showed a thickened pulmonary valve with fused leaflets that show severe systolic doming. There was a discrete subpulmonic membrane about 1.3 cm below the pulmonary valve annulus. Continuous wave Doppler interrogation showed peak systolic pressure gradient of 185 mmHg across the pulmonary valve. Balloon dilation of the pulmonary valve was performed and the pressure gradient came down to 50 mmHg. Follow-up transthoracic echocardiography showed residual pressure gradient of about 50-60 mmHg across the pulmonary valve. The residual pressure gradient appeared to be mainly subvalvar, as seen on the continuous wave Doppler tracing. The patient reported marked improvement in terms of exercise tolerance and subjective symptoms. CONCLUSIONS: Association of subpulmonic membrane with severe pulmonary valvar stenosis, concordant ventriculoarterial connection and intact ventricular septum is rare. When it occurs, the result of percutaneous valve dilation may be suboptimal.