Partial ileal bypass produces sustained improvement in the blood lipid patterns of patients who have had a myocardial infarction and reduces their subsequent morbidity due to coronary heart disease. The role of this procedure in the management of hypercholesterolemia remains to be determined. These results provide strong evidence supporting the beneficial effects of lipid modification in the reduction of atherosclerosis progression.
Balloon dilation angioplasty (BDA) was attempted nine times in eight infants and children with aortic coarctation. In three infants (all with associated ventricular septal defect or atrioventricular canal and marked hemodynamic instability) dilation was attempted at a site of aortic narrowing that had not been operated on previously. Although the coarctation gradient fell 40% or more over the short term in two of the three, there was no angiographic or late gradient evidence of improvement. All three underwent subsequent coarctation surgery. Five dilations were performed in four infants and children who had previously undergone coarctation surgery (end-to-end anastomosis, attempted jump graft, and subclavian flap) and had residual gradients. Dilation was successful in all five cases, resulting in an increase in the diameter at the coarctation site (4.7 +/- 2.6 to 7.7 +/- 4.0 mm, p less than .05) and a decrease in the gradient measured 24 hr after dilation (42.0 +/- 15.5 to 11.8 +/- 11.2 mm Hg, p less than .05). In one child with a long area of hypoplasia of the thoracic aorta and similar lesions of the brachiocephalic vessels, a preliminary attempt to dilate a severely narrowed subclavian artery was unsuccessful. Postdilation angiography demonstrated evidence of intimal tears in three of five successful dilations. Follow-up (1 to 6 months) has demonstrated continued gradient relief in four of five children. BDA is frequently, but not always, a successful treatment for human aortic coarctation. The chief determinant of success appears to be the nature of the lesion; short-term changes in coarctation gradient are unreliable indicators of success of failure. Although BDA was not associated with mortality or significant morbidity in this group of patients, its role in the management of children with coarctation is yet to be determined.
Balloon dilation angioplasty was attempted in 10 infants and children with severe congenital or operative "venous" obstructions. In five children the obstructions were "vena caval" and followed repair for transposition of the great vessels (four patients) or orthotopic liver transplantation (one patient). In the four patients with fixed vena caval or baffle obstructions, balloon angioplasty was successful in relieving the obstruction, decreasing the average gradient (16.0 to 4.5 mm Hg), and increasing the average diameter (3.0 to 8.9 mm) of the obstructed site. One child died 1 week later from an unrelated cerebral hemorrhage; the three survivors have had persistent clinical and angiographic improvement. The fifth child had severe systolic narrowing of the superior baffle limb caused by marked tricuspid regurgitation, which ballooned the superior limb of the baffle against the atrial roof. Angioplasty was unsuccessful in relieving this type of obstruction, which resolved with tricuspid valve replacement. Of the five infants with obstructed pulmonary veins, three had congenitally narrowed vessels associated with total anomalous pulmonary venous connection, one had acquired stenosis, and one had postoperative obstruction after repair of a mixed type of total anomalous pulmonary venous connection. Dilation was unsuccessful in all five patients, but for different reasons: in the congenitally narrowed veins, the waist in the balloon could not be eliminated, even with high dilating pressures; in the infant with acquired stenosis, the vein stretched but did not tear at low dilating pressures; and in the postoperative obstruction, angioplasty increased the diameter of the obstruction but did not increase flow to the affected lung.(ABSTRACT TRUNCATED AT 250 WORDS)
SUMMARY Balloon dilation angioplasty (BDA) was attempted in seven children with either stenosis or hypoplasia (a narrowing greater than 1 cm long extending past the lung hilum) of both right and left pulmonary arteries (PAs). In two of these seven, the procedure could not be performed because of technical difficulties. In each of the remaining five children (11/216 years THE advent of a safe and effective method for dilating atherosclerotic lesions in peripheral arteries' 2 promptly led to the extension of this approach to coronary arteries,3 renal artery stenosis,4 and other lesions throughout the body. The results of balloon dilation angioplasty in these acquired arteriopathies have, in general, been gratifying. However, the extension of balloon dilation angioplasty to children with congenital vascular and cardiac narrowings has been slow. There are good reasons for caution. Congenital stenoses have no soft intimal plaque that may be "squeezed" by the balloon; the goal of therapy is not to restore a vessel lumen, but to enlarge an abnormally small structure; congenital lesions require treatment during growth; and if dilation produces vessel scarring, vascular growth may be impaired. Also, since most important congenital stenoses involve cardiac valves or large vessels near the heart, the ability of an already compromised circulation to tolerate prolonged occlusion of such a vessel is not established. As a result, the current clinical literature on dilating congenital lesions consists of isolated case reports5 -7 or small series8 of cases, with variable results. Postmortem,9 excised specimen10 and animal studies'4 indicate that balloon dilatation of congenital cardiac defects may, under certain circumstances, be safe and effective. Armed with guidelines and experience derived from such studies, we instituted a clinical trial of balloon dilation angioplasty in congenital cardiac lesions in January 1981. Initially, we chose to dilate a lesion for which traditional surgical approaches have been particularly unrewarding: the hypoplastic or stenotic pulmonary artery. Materials and Methods PatientsBefore considering a child for balloon dilation, several hemodynamic and angiographic findings were sought: congenital stenosis or hypoplasia of one or more branch pulmonary arteries; a diameter of the narrowed segment of 6 mm or less; right ventricular pressure greater than 2/3 of left ventricular pressure without associated left-to-right shunt; main pulmonary artery (MPA) pressure of 60 mm Hg or greater; and previous operative attempt at relief of right ventricular outflow obstruction. Children who met all of the above requirements were presented at the combined Pediatric Cardiology/Surgery/Radiology conference at the University of Minnesota. If the conference consensus was that further attempts at gradient relief were warranted, the parents of those children were offered either an attempt at experimental dilation of the pulmonary artery or traditional surgical management. If the pulmonary arterial narrowing was greater...
Hg) despite an increase in animal weight from 3.8 to 19.3 kg. This systolic gradient remained constant in undilated lambs throughout a 6-month follow-up. Dilation produced an immediate 65% increase in the diameter of the coarctation and a 68% decrease in the systolic gradient across the coarctation site. Successful dilation required very high (6-8 atmospheres) dilating pressures. This gradient relief persisted throughout a follow-up of up to 1 year. Although no late sequelae could be attributed to the angioplasty, one lamb suffered an anterior aortic tear (associated with a difficult postdilation wire passage across the dilation site), which resulted in fatal intrathoracic hemorrhage. Gross pathologic inspection demonstrated intimal and medial tears in successfully dilated lambs in the first 3 days after dilation; on late pathologic examination, the intima appeared completely healed, without evidence of aneurysm or accelerated atheroma formation, within 2 months. These results, in conjunction with previous human in vitro studies, support the hypothesis that human aortic coarctation may be a dilatable lesion, although the safe limits and optimal protocols for dilating human coarctations are not known.THE OPTIMAL medical and surgical management of infants and children with aortic coarctation is controversial. Early surgery seems to prevent the development of sustained, lifelong hypertension, ' but may result in a significant gradient later in life.2 3 Late surgery results in excellent long-term technical success,3 4 but may leave the child with lifelong arterial hypertension. 1 I A two-stage surgical approach (operating when necessary on recoarcted aortas) is not optimal because reoperation for recoarctation is, despite recently improved results,3 a difficult and hazardous procedure.6' The advent of a successful balloon dilation catheter for the treatment of peripheral atherosclerotic lesions8' 9 appears to offer a fourth alternative: One could initially dilate the coarctation transcutaFrom the
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