While investigating the outcomes of balloon dilatation procedures in patients with congenital obstructive lesions of the heart, several parallel observations were made. The purpose of this review is to present these observations/phenomena/innovations related to balloon dilatation of pulmonary stenosis (PS), aortic stenosis (AS), and aortic coarctation (AC). In subjects who had balloon pulmonary valvuloplasty (BPV), development of infundibular obstruction, electrocardiographic (ECG) changes, changes in right ventricular filling, role of balloon/annulus ratios on the results of BPV, and double balloon vs. single balloon BPV will be reviewed. In patients who had balloon aortic valvuloplasty (BAV), causes of aortic insufficiency and trans-umbilical venous approach for BAV are tackled. In children who had balloon angioplasty (BA) of AC, aortic remodeling and biophysical response after BA of AC are discussed.

A 58-year-old woman was admitted with acute heart failure. She had a long history of resistant hypertension, with an unremarkable work up for secondary causes in the past. Her brachial blood pressure was 210/70 mm Hg, with ankle blood pressure of 100/70 mm Hg. CT angiogram revealed marked narrowing of the descending thoracic aorta between the left subclavian artery and the diaphragm, consistent with middle aortic syndrome (MAS). She was initially managed with diuretics and antihypertensives. Subsequently thoracotomy revealed a severely hypoplastic segment of the descending aorta. The diseased segment was resected and aortic reconstruction performed. Histopathology showed fragmentation of the medial elastic fibres and fibrosis of the medial and intimal layers. These findings along with gross aortic hypoplasia and absence of features of Takayasu's arteritis, suggest that our patient had congenital MAS. The patient has done well since her surgery. We believe this is the first case of congenital MAS reported in the sixth decade of life.

Ultrasound (US) has been developed as both a valuable diagnostic tool and a potent promoter of beneficial tissue bioeffects for the treatment of cardiovascular disease. These effects can be mediated by mechanical oscillations of circulating microbubbles, or US contrast agents, which may also encapsulate and shield a therapeutic agent in the bloodstream. Oscillating microbubbles can create stresses directly on nearby tissue or induce fluid effects that effect drug penetration into vascular tissue, lyse thrombi or direct drugs to optimal locations for delivery.

The present review summarizes investigations that have provided evidence for US-mediated drug delivery as a potent method to deliver therapeutics to diseased tissue for cardiovascular treatment. In particular, the focus will be on investigations of specific aspects relating to US-mediated drug delivery, such as delivery vehicles, drug transport routes, biochemical mechanisms and molecular targeting strategies.

These investigations have spurred continued research into alternative therapeutic applications, such as bioactive gas delivery and new US technologies. Successful implementation of US-mediated drug delivery has the potential to change the way many drugs are administered systemically, resulting in more effective and economical therapeutics, and less-invasive treatments.

Coarctation of the aorta includes a wide array of anatomical and pathophysiological variations that may cause important long-term morbidity and mortality. Percutaneous techniques, such as balloon dilation and stenting, allow clinicians to safely decrease or abolish most gradients along the aorta, albeit with limitations. Proper patient selection and interventional technique allow clinicians to obtain an adequate stretch or therapeutic tear of the vessel wall, but should avoid complications, such as an excessive tear, dissection, aneurysm formation or rupture. The interventional technique is tailored by patient characteristics such as age, size and growth potential, by characteristics of the lesion such as degree of narrowing, length, angulation(s) and by local regulations.

Six neonates weighing < or = 2,500 g with native coarctation of the aorta underwent balloon dilation. Of the 6 neonates, 4 were female and 2 were male, with a mean age of 14 days (range 9 to 20) and a mean weight of 1,900 g (range 790 to 2,500). The procedure was acutely successful in all 6 patients; the peak gradient decreased from 38 + or - 19 mm Hg to 11 + or - 3 mm Hg. The diameter increased from 1.5 + or - 0.6 mm to 3.6 + or - 0.7 mm. Of the 6 patients, 3 had required no additional intervention at a mean of 42 months after the initial dilation, and 3 had developed restenosis a mean of 2.4 months after the initial dilation and underwent successful redilation. Of the latter 3 patients, 2 developed restenosis and underwent surgical repair 37 and 68 days after the second dilation, and 1 of these patients developed recoarctation after surgery that was treated successfully with balloon dilation 54 days after the end-to-end repair. In conclusion, premature neonates weighing < or = 2,500 g with coarctation of the aorta appear to respond acutely to balloon dilation. Some patients will have a successful long-term result after a single balloon dilation procedure. However, restenosis is common and tends to develop rapidly.

Complications, such as recoarctation or secondary hypertension, probably related to the loss of arterial elasticity, frequently occur after aortic coarctation surgery. This study aimed to investigate arterial compliance as evaluated by automated recording of the QKd interval in patients who underwent repair of coarctation by construction of a subclavian flap compared with those who underwent resection of the narrowed aortic segment with end-to-end anastomosis. Thirty-nine children who underwent surgical repair of aortic coarctation by subclavian flap (n = 19) and by end-to-end anastomosis (n = 20) were enrolled. Arterial stiffness was measured by the noninvasive QKd 100-60 method. Twenty-four-hour ambulatory blood pressure monitoring and a transthoracic echocardiography were also performed. The group of patients who had an end-to-end anastomosis showed better results regarding 24-hour blood pressure profile and QKD 100-60 value compared with those underwent construction of a subclavian flap. Surgical repair of aortic obstruction by end-to-end anastomosis demonstrates better preservation of arterial distensibility than those repaired by subclavian flap. Therefore, it appears to be advantageous, whenever possible, to use the end-end anastomosis approach, which appears to lessen the incidence of the most common complications after aortic arch surgery.

Obstructive lesions in the aortic arch are comprised of discrete coarctation, tubular hypoplasia and interruption. This review discusses the anatomy of the lesions relevant to interventional treatment. Catheter intervention, using not only balloon angioplasty but also stent implantation for coarctation, has been developed over the past couple of decades as an alternative treatment to surgery. Several studies have reported long-term outcome and the benefits of surgery and catheter intervention for treating obstructive lesions in the aortic arch but more studies are needed for comparable evaluations. The development of imaging and further improvement of surgical and catheter intervention, such as hybrid intervention or new devices, will help in removing the obstruction safely.

Coarctation of the aorta is a common congenital lesion that may often be repaired or intervened upon early in life. The management of patients with this disorder revolves around the concept that although the coarctation may be treated, what remains is a diffuse systemic cardiovascular disorder. Careful clinical care and investigation is required to reduce morbidity from recurrent disease and residual lesions. The natural and modified history of the disorder is reviewed. This article focuses on the clinical care of adults with repaired coarctation and includes a review of clinical goals and investigation as well as indications for reintervention.

Primary stenting for aortic coarctation is frequently used in adult patients. Aortic rupture remains an infrequent complication. A number of strategies, including the use of covered stents, have been proposed to reduce the risk of this catastrophic complication. We describe a 51-year-old female who underwent stenting of aortic coarctation using a covered stent, which was complicated by aortic rupture. Treatment consisted of placement of an additional covered stent to seal the site of aortic disruption. The prevention and management of aortic rupture complicating aortic coarctation stenting are discussed.

To assess the procedural, clinical, angiographic, and hemodynamic outcomes, including ambulatory blood pressure monitoring at 1 year in adolescent and adult patients undergoing primary stenting for treatment of aortic coarctation.

Stenting is widely used for treatment of aortic coarctation. Data regarding efficacy of this treatment for control of hypertension at 1 year is scant, with only one reported series of planned angiographic follow up. The impact of newer type stents for this procedure is also unknown.

Thirty-seven patients undergoing stenting for aortic coarctation, over a 3-year period in a tertiary centre were studied as part of an observational protocol.

Peak gradient across the coarctation fell from 28.3 +/- 15.1 to 3.7 +/- 4.1 post procedure and was 11.9 +/- 8.9 mmHg (P < 0.05 compared to baseline) at 1 year. There was one major complication (2.7%), with no deaths. Small aneurysms were seen in three patients (13%) on follow up angiography at 1 year. Right arm systolic blood pressures fell from 155 +/- 19 to 132 +/- 22 (P < 0.05) at 6 weeks and was 132 +/- 16 mmHg (P < 0.05 compared to baseline) at 1 year. Ambulatory average systolic blood pressures fell from 142 +/- 14 to 133 +/- 15 at 6 weeks (P < 0.05) and to 125 +/- 12 mmHg (P < 0.05 compared to baseline) at 1 year. No significant differences were seen in procedural outcomes between patients receiving Palmaz and CPNumed stents.

Primary stenting of aortic coarctation in adolescents and adults results in excellent clinical and angiographic outcomes and sustained hemodynamic benefits at 1 year as evidenced by significant reduction in systolic blood pressure and gradients. Close follow up is required to monitor aneurysm formation.

Surgical repair has a dramatic impact on the prognosis of aortic coarctation. However, in many units, endovascular repair by balloon angioplasty or stenting has become the primary treatment. Short-term results are excellent but there are few data on later outcome. Care needs to be exercised in patient selection, and although major complications are rare, when they do occur they may be devastating. This article reviews our current practice for the assessment selection and follow-up of these patients.

Balloon angioplasty for native coarctation of the aorta (CoA) in adults, though promising, is sometimes limited by significant residual gradient (>20 mm Hg). Few studies available have reported on use of balloon-expandable stents in such a situation. We evaluated the use of self- and balloon-expandable stents in patients with suboptimal response to balloon angioplasty (BA).

Twenty-one hypertensive patients (age, 18 to 61 years; mean, 28.6 +/- 11.2 years) with native CoA and in whom results of BA were suboptimal (ie, residual peak systolic gradient [PSG] >20 mm Hg) underwent stent implantation. Balloon-expandable Palmaz stents were implanted in 5 patients (group A) and self-expandable nitinol aortic stents in the remaining 16 patients (group B).

In group A, PSG decreased from 62.8 +/- 10.6 (53 to 80) mm Hg to 28.1 +/- 6.3 (22 to 39) mm Hg after BA. Systolic gradient further decreased to 8.3 +/- 3.9 (2 to 16) mm Hg (P <.001) after implantation of the balloon-expandable Palmaz stent. In group B, PSG decreased from 70.2 +/- 24.6 (40 to 110) mm Hg to 28.4 +/- 9.8 (22 to 42) mm Hg after BA and further reduced to 9.0 +/- 5.5 (4 to 16) mm Hg (P <.001). One of these patients had a nitinol self-expandable stent implanted after a Palmaz stent embolized immediately after deployment. Nitinol stents were easier to deploy and conformed better to aortic anatomy compared with balloon-expandable stents. In group A, the diameter of the coarcted segment increased from 3.8 +/- 0.8 mm to 13.3 +/- 0.8 mm (P <.001) after stent implantation and in group B it increased from 4.5 +/- 1.1 mm to 14.1 +/- 2.1 mm (P <.001). There was no significant difference between the two groups in the PSG and diameter of the coarcted segment before and after stent implantation. With the exception of one case, in which a Palmaz stent embolized, there was no other complication in our series. On follow-up of 12 to 71 months (mean, 40.7 +/- 5.8 months) all the implanted stents remained in their original position and none showed evidence of fracture. Improvement in hypertension was seen in 20 of 21(95.2%) of the patients. On recatheterization and angiography 1.2 +/- 0.6 years after implantation in 19 patients, one patient showed an increase in PSG to 27 mm Hg across the nitinol stent and underwent successful redilation. No increase in gradient was seen in other patients. Beneficial late remodeling was seen in 10 of 14(71.4%) of patients restudied after implantation of self-expandable stent. None of the patients showed aneurysm formation.

Stent implantation is safe and effective in improving suboptimal results after BA for CoA. Self-expandable stents were easier to implant, adapted better to the wall of the aorta, and in most patients had similar efficacy in reducing coarctation as balloon-expandable stents.

Balloon angioplasty of recurrent coarctation of the aorta is considered a low-risk procedure with high success rate. In the literature, the major complications are death, rupture of the aorta, recoarctation, aneurysm formation, cerebrovascular accident, and femoral artery thrombosis. Spinal cord ischemia as an unusual complication of balloon angioplasty is reported.

We sought to investigate the clinical impact of balloon angioplasty for native coarctation of the aorta (CoA) and determine predictors of outcome.

Balloon dilation of native CoA remains controversial and more information on its long-term impact is required.

Hemodynamic, angiographic and follow-up data on 69 children who underwent balloon angioplasty of native CoA between 1988 and 1996 were reviewed. Stretch, recoil and gain of CoA circumference and area were calculated and related to outcomes.

Initial systolic gradients (mean +/- SD, 31+/-12 mm Hg) fell by -74+/-27% (p < 0.001), with an increase in mean CoA diameters of 128+/-128% in the left anterior oblique and 124+/-87% in the lateral views (p < 0.001). Two deaths occurred, one at the time of the procedure and one 23 months later, both as a result of an associated cardiomyopathy. Seven patients had residual gradients of >20 mm Hg. One patient developed an aneurysm, stable in follow-up, and four patients had mild dilation at the site of the angioplasty. Freedom from reintervention was 90% at one year and 87% at five years with follow-up ranging to 8.5 years. Factors significantly associated with decreased time to reintervention included: a higher gradient before dilation, a smaller percentage change in gradient after dilation, a small transverse arch and a greater stretch and gain, but not recoil.

Balloon dilation is a safe and efficient treatment of native CoA in children. Greater stretch and gain are factors significantly associated with reintervention, possibly related to altered elastic properties and vessel scarring.

To determine the early results of balloon expandable stent implantation for aortic coarctation or recoarctation.

Prospective observational study.

Two paediatric cardiology tertiary referral centres.

17 patients, median age 17 years (range 4.4 to 45) and median weight 61 kg (17 to 92). Six had native aortic coarctation and 11 had aortic recoarctation; 14 had upper limb systolic hypertension. Of those with recoarctation, eight had had at least one previous balloon dilatation attempt and two of these patients also had further surgical interventions.

Balloon expandable Palmaz iliac stent implantation.

Systolic pressures gradients, minimum aortic diameter, upper limb blood pressures, and incidence of aneurysm formation.

18 stents were implanted during 18 procedures in the 17 patients. Mean peak systolic pressure gradient fell from 26 mm Hg (95% confidence interval (CI), 21 to 31 mm Hg) before to 5 mm Hg (2 to 8 mm Hg) after stent implantation (p < 0.001), and mean minimum aortic diameter increased from 7 mm (95% CI, 6 to 8 mm) before to 11.3 mm (10 to 12.6 mm) after implantation (p < 0.001). Complications occurred in five patients (bleeding in two, stent migration in two, and aneurysm formation in one). Two patients remained borderline hypertensive and eight were receiving antihypertensive treatment at most recent assessment.

Stent implantation for aortic recoarctation and native coarctation gives good immediate results. Careful follow up is necessary to evaluate complications and the long term effect on blood pressure.

Invasive techniques in pediatric cardiology have experienced a big change since the 80's. The growth of non-invasive methods for diagnosing congenital heart defects has made the number of diagnostic catheterizations decrease remarkably. On the other hand, the notable development of pediatric interventional catheterization techniques will allow that, in the near future, the number of therapeutic catheterizations overcomes the diagnostic ones in our country. The former are more difficult and dangerous, so they require experienced and skilled hands and more economic resources. This chapter is divided in three main sections: I) Requirements and equipment needed for pediatric invasive techniques; II) Current indications, contraindications and complications of the diagnostic catheterization, and III) Techniques, indications and results of pediatric therapeutic catheterization: current state. Likewise, we state the suitability or not for these therapeutic procedures in different cardiac anomalies.

Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

To determine outcome of stent implantation in patients with middle aortic syndrome.

Prospective study, case series.

A tertiary paediatric cardiology centre in a children's hospital.

Five patients, aged 4 to 17 years (mean 11.4 years), with upper limb hypertension due to middle aortic syndrome.

Stents were implanted in the mid/lower thoracic/upper abdominal aorta.

Satisfactory deployment of stents and blood pressure control.

In all patients, angiocardiography showed long segment stenosis in the mid or lower thoracic/upper abdominal aorta. The pressure gradient was between 40 and 90 mm Hg (mean 63.2 mm Hg). Seven Palmaz stents were implanted. Immediately after implantation, the gradient decreased to between 0 and 35 mm Hg (mean 13.6 mm Hg). Angiography showed a satisfactory result with widely patent stents in all. In one patient, thrombosis of the stent occurred six days after implantation. This was successfully treated with infusion of alteplase, further balloon dilatation, and implantation of a second stent overlapping the first, both dilated to 10 mm diameter. One patient had elective redilatation of the stent six months after implantation, with further reduction of the gradient from 35 mm Hg to 10 mm Hg. At the latest follow up between three and 20 months (mean 12.2 months) after stent implantation, in four patients blood pressure was better controlled with antihypertensive drugs. One patient was normotensive without drugs. Computed tomography showed no aneurysm formation in the region of the stents.

Stent implantation is a preferable alternative to surgery in the treatment of patients with middle aortic syndrome and merits further evaluation.

To evaluate the role of biophysical response of the coarcted segment to balloon dilatation in the causation of aortic recoarctation.

Tertiary care centre/university hospital.

Retrospective case series.

Records of 67 consecutive infants and children undergoing balloon angioplasty of native aortic coarctations were examined for an 8.7 year period ending September 1993. At 12 months (median) follow up catheterisation, 15 (25%) of 59 children developed recoarctation, defined as a gradient > 20 mm Hg. Stretch (balloon circumference--preballoon coarcted segment circumference/preballoon coarcted segment circumference), gain (postballoon coarcted segment circumference--preballoon coarcted segment circumference), and recoil (balloon circumference--postballoon coarcted segment circumference) were calculated from measurements obtained from cineangiograms performed before and immediately after balloon dilatation.

The stretch in 44 children without recoarctation (2.18 (1.23)) was similar (p > 0.1) to that in 15 children with recoarctation (1.90 (0.65)), implying that similar balloon dilating stretch was applied in both groups. Greater gain (p < 0.05) was observed in the group without recoarctation (8.8 (8.0) mm) than in the recoarctation group (5.7 (2.7) mm) but this was not substantiated in the infant population. However, the recoil was greater (p < 0.001) in the group without recoarctation (5.1 (4.3) mm) than in the recoarctation group (2.1 (1.1) mm); this was also true in the infant group.

Greater recoil in the patients without recoarctation implies preservation of intact elastic tissue in the coarcted segment. In the recoarctation group, with less recoil, the elastic properties may not have been preserved, thereby causing recoarctation. There might be a more severe degree of cystic medial necrosis in the recoarctation group than in the no recoarctation group. This needs confirmation in future studies.

Intravascular ultrasound (IVUS) studies performed after balloon dilation provide a method for evaluating the adequacy of angioplasty and the nature of associated changes in vessel walls. Previously, IVUS studies required the use of separate scanning catheters inserted independently before and after balloon angioplasty. We tested a 0.035-in, 30-MHz IVUS transducer wire that images from within commercially available 5F balloon dilation catheters.

Seven stenoses were created in the left pulmonary artery (n = 3) and in the aortic isthmus (n = 4) in six lambs (weight, 3.4 to 12.5 kg). The balloon catheter selected was advanced across the stenotic area and the IVUS wire advanced in the guide lumen to the center of the balloon. Continuous IVUS images were obtained through balloons before, during, and after dilation. Transballoon imaging confirmed balloon location within the stenotic segment. Luminal diameters of stenotic and adjacent vessel segments before and after angioplasty by IVUS showed good correlation with angiographic measurements (r = .93, P < or = .001). After successful dilation, imaging during deflation allowed the assessment of vascular elastic recoil, mural dissection, and luminal size without requiring changes in balloon position. Repeat dilation could be undertaken and the inflation pressure and technique modified on the basis of the observed results.

This transballoon IVUS system provides important on-line information about lumen diameter and wall structure for evaluation of angioplasty without the need for catheter changes, providing a method to possibly reduce the likelihood of excessive wall damage and to potentially reduce the number of angiograms required to accomplish and confirm results.

To evaluate the usefulness of balloon angioplasty for relief of native aortic coarctation, we reviewed our experience with this procedure, with special emphasis on follow-up results.

Controversy exists with regard to the role of balloon angioplasty in the treatment of native aortic coarctation.

During an 8.7-year period ending September 1993, 67 neonates, infants and children underwent balloon angioplasty for native aortic coarctation. A retrospective review of this experience with emphasis on long-term follow-up forms the basis of this study.

Balloon angioplasty produced a reduction in the peak-to-peak coarctation gradient from 46 +/- 17 (mean +/- SD) to 11 +/- 9 mm Hg (p < 0.001). No patient required immediate surgical intervention. At intermediate-term follow-up (14 +/- 11 months), catheterization (58 patients) and blood pressure (2 patients) data revealed a residual gradient of 16 +/- 15 mm Hg (p > 0.1). When individual results were scrutinized, 15 (25%) of 60 had recoarctation, defined as peak gradient > 20 mm Hg. Recoarctation was higher (p < 0.01) in neonates (5 [83%] of 6) and infants (7 [39%] of 18) than in children (3 [8%] of 36), respectively. Two infants in our early experience had surgical resection with excellent results. Three patients had no discrete narrowing but had normal arm blood pressure and had no intervention. The remaining 10 patients had repeat balloon angioplasty with reduction in peak gradient from 52 +/- 13 to 9 +/= 8 mm Hg (p < 0.001). Reexamination 31 +/- 18 months after repeat angioplasty revealed a residual gradient of 3 to 19 mm Hg (mean 11 +/- 6). Three (5%) of 58 patients who underwent follow-up angiography developed an aneurysm. Detailed evaluation of the femoral artery performed in 51 (88%) of 58 patients at follow-up catheterization revealed patency of the femoral artery in 44 (86%) of 51 patients. Femoral artery occlusion, complete in three (6%) and partial in four (8%), was observed, but all had excellent collateral flow. Blood pressure, echocardiography-Doppler ultrasound and repeat angiographic or magnetic resonance imaging data 5 to 9 years after angioplasty revealed no new aneurysms and minimal (2%) late recoarctation.

On the basis of these data, it is concluded that balloon angioplasty is safe and effective in the treatment of native aortic coarctation; significant incidence of recoarctation is seen in neonates and infants; repeat balloon angioplasty for recoarctation is feasible and effective; and the time has come to consider balloon angioplasty as a therapeutic procedure of choice for the treatment of native aortic coarctation.

Balloon angioplasty of native coarctations of the aorta is one of the most controversial facets of the pediatric interventional cardiologist's practice. We have evaluated the history and experimental rationale of this technology. Presently accepted techniques are outlined and controversies intrinsic in performance of this procedure are discussed. Acute, short-term, and long-term results are reviewed with particular emphasis on differences in success of the procedure as related to patient age. Common and significant complications are discussed and in some cases compared to analogous surgical complications. Newer technologies and approaches to interventional therapy for coarctation of the aorta are also discussed.

OBJECTIVES, This retrospective analysis was designed to examine the intermediate and long-term effects of balloon angioplasty for native coarctation of the aorta and to determine whether any factors are predictive of outcome.

Balloon angioplasty for native coarctation of the aorta is controversial. Concerns exist over lack of long-term follow-up and possible formation of aneurysms. The role of transverse arch and isthmus hypoplasia after balloon dilation is unknown.

Included in the study were all patients 3 days to 29 years old (mean age 4.6 years) referred for possible balloon dilation to the pediatric cardiac catheterization laboratory with evidence of a discrete coarctation of the aorta. The hemodynamic data, angiograms and clinical records of 102 patients were examined, with follow-up data from 2 to 117 months (median 36.2) available in 92 patients.

Immediate success with balloon angioplasty was achieved in 93 (91.2%) of the 102 patients. Seventy-one patients (77.2%) with intermediate follow-up data (range 12 to 117 months) available are asymptomatic and normotensive, with insignificant arm to leg blood pressure gradients (< or = 20 mm Hg). Twenty-one patients (22.8%) with an initial successful result developed an increase in gradient 2 at 86 months after angioplasty, requiring reintervention in 18. Follow-up > 72 months is available in 17 patients, 16 of whom are normotensive and have not required additional intervention. No additional intervention was needed in 88.4% of older children and infants > 7 months old. Ten of the 13 surviving neonates who initially had a successful dilation required reangioplasty or operation 14 days to 10 months (median 4.6 months) after angioplasty. Transverse arch hypoplasia had minimal effect on follow-up blood pressure gradient, whereas isthmic hypoplasia was associated with reintervention in 50%. A small aneurysm was noted in 2 (1.9%) of 102 patients.

Balloon angioplasty of native aortic coarctation is effective in infants and older children. In neonates, balloon angioplasty provides effective palliation only. Aneurysm formation is rare; however, lifetime follow-up is warranted.

Controversy still exists over the optimal balloon size, extent of vascular disruption, and long-term results of balloon dilation therapy for coarctation of the aorta. Intravascular ultrasound imaging has been used in patients with coronary artery disease to provide further insight into the anatomy of atherosclerotic lesions and the results of angioplasty and atherectomy. Initial observations of the results of balloon dilation of coarctations with intravascular ultrasound imaging have shown prominent dissections of the inner vascular layers that are often not detected by angiography. The purpose of this study was to test a new transballoon catheter ultrasonic imaging system capable of on-line direct visualization of lumen diameter and vessel wall structure for imaging before, during, and after dilation in an acute animal model of aortic coarctation.

Abdominal aortic coarctations were created surgically in three 14-19-kg mongrel dogs by using Teflon gauze ties. The 6.8F ultrasound balloon catheter was placed percutaneously in the right femoral artery through a 9F sheath. Ultrasound imaging allowed measurement of the coarctation diameter, characterization of the vessel wall structure, localization of the stenosis, and placement of the midportion of the balloon at the narrowest area. Imaging through the balloon was performed through several dilations (five to eight per animal), and after balloon deflation, it provided information on postdilation diameter, intimal tears, long-segment dissections, and intramural thrombi, findings that were confirmed at postmortem examination.

The results of this study demonstrate that imaging with a new intraballoon ultrasound device is feasible during inflation to therapeutic dilation pressures; it allows visualization of the changes in diameter and vascular wall structure after serial dilations without having to recross the obstructed area. Adaptation to larger balloon sizes and lower frequencies should make this system applicable to interventional catheterizations in patients with congenital cardiac and vascular lesions.

Balloon angioplasty of the coarctation of the aorta can result in intimal or medial or even adventitial dissections as demonstrated by in vitro studies and animal experiments. As a typical sign of stretching of the aortic wall, patients complain of pain during the angioplasty procedure. In the literature, aortic wall rupture and ventricular fibrillation during the procedure are reported. Additional sudden deaths can occur within 40 hours after the procedure. Mortality ranges from 0.1% to 2.5%. By transesophageal echocardiography, monitoring of balloon angioplasty, control of the positioning of the balloon, and control of the results and detection of complications are possible. Intimal as well as medial dissections can be detected with observed healing for intimal but also medial dissections. In order to avoid the patient's discomfort, intraaortic ultrasound will be used in the future, when major methodological improvements are done. Computed tomography demonstrates medial dissections but is not able to visualize intimal dissections. Using computed tomography and magnetic resonance after angioplasty of the coarctation of the aorta, irregularities are described in up to 17% of the patients. For angiography, a low detection rate of medial dissections has to be expected, when not biplane angiographies of the whole thoracic aorta are performed. Medial dissections can be seen, but intimal dissections are missed. In conclusion, a review of the literature demonstrates a high incidence of intimal and medial dissections after angioplasty of the coarctation of the aorta with spontaneous healing in most patients. As is the way with coronary angioplasty, aortic wall ruptures are rare, but stand-by surgery is necessary.

Between October 1982 and May 1990, balloon dilation of aortic recoarctation was attempted in 27 patients. In 1 case dilation was not performed owing to suspected aortic perforation. The remaining 26 patients had 30 procedures. The age at the first dilation ranged between 2.6 months and 18.3 years. After dilation, systolic gradient decreased from 49 +/- 17 mm Hg to 20 +/- 17 mm Hg (p less than 0.001). A reduction of gradient to less than or equal to 20 mm Hg occurred after the first dilation in 17 of 26 (65%) patients. Residual gradients between 25 and 80 mm Hg were present in the remaining 9 patients. During follow-up of 2 months to 6.7 years, 5 of 17 patients with a good initial result developed further recoarctation (2 had successful redilation, 2 had reoperation, and 1 is awaiting repeat dilation). Of 9 patients with gradients greater than 20 mm Hg after the first dilation, 1 had successful redilation and 3 had reoperation. The remaining 5 patients are being managed conservatively. 2 patients developed aneurysms after dilation (1 immediately and the other at 2 months). In all, 15 patients (58%) had a good, and 11 (42%) a poor late hemodynamic result. Aortic diameters at different levels of the aortic arch and at the reconstructed isthmus (normalized to the aorta at the level of the diaphragm) were significantly higher in the group with a good late result than in that with a poor one. Balloon/aortic diameter ratio at diaphragm level also had a significant influence on the late results.

We report our experience in 37 patients with aortic coarctation who underwent balloon aortoplasty. Of the 37, the lesion was native in 34 cases. Clinical re-evaluation was possible in 22 patients, with a mean follow-up period of 13 months and, of these, 21 patients were asymptomatic. Haemodynamic and angiographic studies were performed in 13 patients, with a mean period of follow-up of 12 months, showing excellent results in 11 patients. Aneurysmal formation had occurred in one and recoarctation in the other patient. Our experience has proved that balloon aortoplasty is an effective method for treating patients with aortic coarctation. Adequate selection in terms of the morphology of the coarctation and the size of the balloon catheter are crucial factors in the success of the procedure.

Data on dilation of 141 native coarctation procedures in 140 patients between 3 days and 29 years of age were submitted to the Valvuloplasty and Angioplasty of Congenital Anomalies (VACA) Registry. Fifteen patients were less than 4 weeks old, 15 between 1 month and 12 months old and 110 patients over 1 year old. The immediate results confirmed that native coarctations could be effectively dilated in both infants and older children. The data do not support any conclusions concerning balloon size relative to results or complications. There were 24 complications (17%) reported with 1 death after 3 days and after intervening surgery in an infant with associated persistent ductus arteriosus. There were 2 early and 6 late "aneurysms" reported after the coarctation dilations with insufficient immediate and no long-term information about the significance of these. The VACA Registry data suggest that dilation of native coarctations can be performed effectively and relatively safely but do not answer whether this procedure should be performed.

Balloon coarctation angioplasty (BCA) was performed in eight patients (five male and three female) who were 14-49 years old (mean, 27.3 years) with isolated discrete unoperated coarctation of the aorta (n = 7) and postoperative recoarctation (n = 1). BCA was successful in seven of eight patients, resulting in a decrease in the gradient (64 +/- 19 to 16 +/- 13 mm Hg, p less than 0.01), an increase in the diameter at the coarctation site (0.9 +/- 0.4 to 1.6 +/- 0.4 mm, p less than 0.01). Follow-up (6 months) has demonstrated continued gradient relief (6 +/- 9 mm Hg) and diameter increase (1.6 +/- 0.2 cm). Monitoring was performed by transesophageal echocardiography (TEE) during BCA, and before and after BCA angiography and after BCA computed tomography. In three of seven patients, immediately distal to the BCA site, intimal flaps (1-2 cm) could be detected by TEE but not by angiography or computed tomography. Follow-up TEE showed spontaneous healing in two and persistence in one patient. By TEE and computed tomography in one of eight patients during follow-up, intima and media dissection was found with pleural effusion and spontaneous healing. In one female patient, aortic dissection occurred after successful uneventful BCA, detected by TEE at the 6-month follow-up study and subsequently confirmed by biplane angiography, not detected by computed tomography and previous monoplane angiography. Because of the significant morbidity of BCA in this group of patients, its role in the management of adults with coarctation has yet to be determined. Further long-term follow-up studies will demonstrate whether the observed intima and media dissection by TEE after BCA are related to aneurysm formation.