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Aortic Coarctation - Who Should Be Dilated? Or Operated?

P. Syamasundar Rao, MD, FACC

Professor of Pediatrics
Director, Center for Transcatheter Treatment of Heart Defects in Children
Saint Louis University School of Medicine
Cardinal Glennon Children's Hospital
St. Louis, Missouri, USA

Introduction
The Controversy
Discussion
Surgery/Balloon - Who and What
Conclusion
References

Introduction

Since the initial application of Gruntzig's technique1 of balloon angioplasty to human aortic coarctation by Sos,2 Singer,3 Sperling4 and their associates, balloon coarctation angioplasty has evolved and has, in the opinion of some workers including that of the author, achieved the status of "effective alternative" to the standard surgical therapy. Others disagree. In this review, I will address the controversy of utility of balloon angioplasty in the management of native aortic coarctation. Balloon angioplasty of post-surgical aortic recoarctation is generally accepted as a first-therapeutic option and therefore will not be dealt with in the foregoing discussion.

The Controversy

Following the report of safe and successful relief of native, aortic coarctation by balloon angioplasty in a large group of children by Lababidi et al5, doubt was casted on these results by an editorial published in the same issue of the Journal6: "Now that we can dilate, should we?" This appears to be based on poor results in the dog model7 and poor initial clinical experience in less than hand-full patients.8 The recommendation of balloon angioplasty for native coarctation was further clouded by the report of aneurysms at the site of coarctation following balloon dilatation.9 This abstract was later published as a full paper in a surgical journal.10 We11 and others5,12,13 continue to advocate balloon angioplasty for native coarctation. The VACA (Valvuloplasty and Angioplasty of Congenital Anomalies) Registry analyzed the multi-institutional data of balloon angioplasty for native14 and post-surgical15 aortic coarctation and reported similar pressure gradient reduction (native: 48 ± 19 to 12 ± 11 mmHg; post-surgical: 42 ± 20 to 9 ± 3 mmHg; p > 0.1), mortality rate (0.7% vs 2.5%; > 0.05) and prevalence of complications (9.9% vs 8.5% p > 0.1). With these identical results, one would anticipate similar recommendations for use of balloon therapy for both types of coarctations. Instead, the conclusion for native coarctaions14 was "the question remains not can it be done, but should it be done?" whereas recommendation for post-operative recoarctaions15 was ".... balloon angioplasty for relief of residual or recurrent aortic coarctation offers an acceptable alternative to repeat surgical repair." I opined that this is not logical and that objectivity of scientific interpretation should be maintained.16

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Discussion

The evidence supporting the use of balloon angioplasty as an alternative to surgery has been presented in detail at various national and international scientific societies and in several publications;17-19 the presentations addressed effectiveness and safety of balloon angioplasty as well as a comparison with surgical results.

The effectiveness in terms of immediate reduction of pressure gradients across the coarctation and improvement in the diameter of the coarcted segment has been demonstrated both in our own case material as well as that of other investigators referenced extensively elsewhere.19-21 Relief of symptoms caused by congestive heart failure and/or hypertension, the indications for balloon therapy, was observed. None to only six percent of patients required immediate surgical intervention. These impressive immediate results were evident in all age groups; neonates, infants, children and adults.

The intermediate-term (< 2 years) follow-up results suggested continued reduction of the pressure gradient for the group as a whole, but some patients developed recoarctation, defined as a peak gradient > 20 mmHg. This recurrence is high in neonates,22,23 moderate in infants,22 and low22 in children. However, the recurrent obstruction could be relieved by repeat balloon angioplasty22,24 or surgery.25

Reports addressing long-term (> 5 years) results are scanty,22,26 but the available data on respectable number of patients suggest little additional recurrence beyond what was observed at the intermediate-term follow-up, occasional need for reintervention and generally well controlled blood pressures.

Thus, the review of our own experience and that of others suggests effectiveness of balloon angioplasty in relieving aortic obstruction.

The safety was assessed by reviewing mortality and complication rates. With rare exception, the mortality was related to the associated cardiac defects and not to balloon angioplasty. Partial or complete occlusion of the femoral artery in nearly 15% of patients is problematic, but limb growth retardation was not seen.27 Use of umbilical artery28 in the neonates and antegrade approach,29 when feasible averts the problem of femoral artery compromise. The recent availability of balloon dilatation catheters that can be passed through #4 French sheaths, may further reduce femoral artery occlusion. Aneurysms, tabulated elsewhere,19 following balloon dilatation, were observed in 10.8% of patients. None of these have ruptured spontaneously nor required urgent surgery, although elective resection and repair was undertaken10,22,30 in some of these patients. Equally important is the higher prevalence of aneurysms following surgery.31-33

It is concluded that the mortality and complication rates are within acceptable range such that balloon angioplasty may be considered safe.18,19

Comparison with surgery is fraught with problerns,17-19 but a careful review of published reports,21 the single randomized study in children34 and non-randomized contemporary comparison in infants35 revealed similar mortality and recoarctation rates, but lower morbidity and complication rates with balloon than with surgical therapy.18,19 The issues related to recoarctation, aneurysmal formation and arterial complication have been discussed above. Complications such as paraplegia and paradoxical hypertension remain significant after surgical therapy whereas such problems are rare, and if present, mild and inconsequential following balloon therapy. In addition, higher cost associated with longer hospital stay, need for intubation and general anesthesia and residual scar of operation are the other disadvantages associated with surgical treatment.

Thus, it may be concluded that balloon angioplasty of aortic coarctation is safe and effective and compares, in many respects, favorably with surgery and is an effective alternative to surgical management.

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Surgery/Balloon - Who and What

Based on an extensive review of the subject and personal experience, some generalizations with regard to therapy of aortic coarctations may be made:

1. Patients with recoarctation following surgical repair of aortic coarctations, interrupted aortic arch and arch repair for hypoplastic left heart syndrome (Norwood) are considered by all workers in the field to be candidates for balloon angioplasty and balloon therapy is the first option treatment in the management of post-surgical aortic recoarctations.

2. Children (> 1 year) and adults with native coarctations of the discrete type are also candidates for balloon angioplasty. There appears to be consensus on this group by most, if not all, cardiologists. If there is more than mild hypoplasia of the isthmus or of transverse aortic arch, most interventional pediatric cardiologists lean towards intravascular stents, especially in the adolescents and young adults. Some cardiologists and most surgeons may recommend surgical intervention for this group of patients.

3. Patients with recurrence following previous balloon angioplasty may benefit from repeat balloon dilatation,24 especially if the recurrent narrowing is a discrete obstruction. lf the recoartation is a long segment obstruction, surgical therapy in younger children and stents in adolescents and adults should be considered.

4. Native coarctation in neonates and young infants is perhaps the most debated subject. Many cardiologists would recommend surgical intervention while a few cardiologists including myself advocate balloon therapy.

lf there is discrete coarctation with mild to, at worst, moderate hypoplasia of the isthmus and/or the aortic arch, balloon angioplasty is our choice. The fact that balloon angioplasty relieves symptoms of heart failure and hypertension and helps avoid immediate surgery, is a great benefit to the patient, even though there is a high probability of recurrence. Should there be recoarctation, it can be treated with repeat balloon angioplasty or even surgery, when the infant is stable and less acutely ill.

There are many clinical situations in which balloon angioplasty is extremely useful: 1) neonates presenting with severe cardiac decompensation and shock-like picture,28 2) infants presenting with severe myocardial dysfunction with "hypertensive cardiomyopathy,"36 3) cerebral hemorrhage presumably due to severe hypertension secondary to aortic coartation19 and 4) severe hepatic disease awaiting liver transplantation.19 In these described clinical scenarios, balloon angioplasty avoids aortic cross-clamping that is required for surgical repair and thus beneficial to the patient in terms of avoiding additional afterload on the left ventricle, accentuating cerebral hemorrhage and further liver damage that anesthesia might entail, respectively.

We also advocate balloon angioplasty in neonates and infants with other heart defects such as a large ventricular septal defect or other complex cardiac defects. In these infants, relief of coarctation by balloon angioplasty controls heart failure by reducing left ventricular pressure and volume overload. The infant may not require additional palliation (such as banding) or correction, or may postpone such a procedure to a more appropriate time.

The coarctations for which we recommend surgical therapy are those that have moderate to severe hypoplasia of the aortic arch or isthmus. Even in these infants, biodegradable stents may be the way to go once stent delivery system and clinical utility data become available.

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Conclusion

Extensive review of the published data and personal experience for over 15 years indicate that balloon angioplasty is effective in relieving the aortic obstruction and the attendant symptoms. The procedure is proven to be safe because of low mortality and low complication rate. Although there are no controlled studies, detailed comparison of available data on balloon versus surgical therapy suggest that balloon angioplasty is better in many respects than surgical therapy.

A high rate of prevalence of recoarctation in neonates and young infants undergoing balloon angioplasty is of concern. But, as I emphasized, since the very first report on balloon angioplasty more than 10 years ago in the British Heart Journal, the important feature of balloon angioplasty in the neonate and young infant is that it produces abatememt of symptoms of heart failure and hypertension and helps avoid immediate surgery. Should recurrence ensue, it can be treated by repeat balloon angioplasty or even surgery, if one prefers, when the infant is stable and less acutely ill.

I believe that balloon angloplasty has an important role in the management of sick neonates with coarctation. The data indicate that balloon angioplasty is an effective and safe alternative to surgical therapy of native aortic coarctation.

References

1. Gruntzig AR, Senning A, Siegenthaler WE. Nonoperative dilatation of coronary artery stenosis: percutaneous transluminal coronary angioplasty. New Engl J Med 1979;301;61-8
2. Sos T, Sniderman KW, Rettek-Sos B, Strapp A, Alonso DR. Percutaneous transluminal dilatation of coarctation of the thoracic aorta-postmortem. Lancet 1979;2:970-1
3. Singer MI, Rowen M, Dorsey TJ. Transluminal aortic balloon angioplasty for coartaction of the aorta in the newborn. Am Heart J 1982; 103:131-2
4. Sperling DR, Dorsey TJ, Rowen M, Gazzaniga AB. Percutaneous transluminal angioplasty of congenital coarctation of the aorta. Am J Cardiol 1983;51:562-4
5. Lababidi ZA, Daskalopoulos DA, Stoeckle H, Jr. Transluminal balloon coarctation angioplasty: experience with 27 patients. Am J Cardiol 1984;54:1288-91
6. Lock JE. Now that we can dilate, should we? (editorial). Am J Cardiol 1984;54:1360
7. Castaneda-Zuniga WR, Lock JE, Vlodaver Z, et al, Transluminal dilatation of coarctation of the abdominal aorta: an experimental study in dogs. Radiology 1982;143:696-7
8. Lock JE, Bass JL, Amplatz K, Fuhrman BP, Castaneda-Zuniga W. Balloon dilatation angioplasty of aortic coarctations in infants and children. Am Heart J 1983; 106:752-3
9. Marvin WJ, Mahoney LT, Rose EF. Pathological sequelae of balloon dilation angioplasty for unoperated coarctation of the aorta in children (Abstract). J Am Coll Cardiol 1986;7:117A
10. Brandt B, III, Marvin WJ, Jr., Rose EF, Mahoney LT. Surgical treatment of coarctation of the aorta after balloon angioplasty. J Thorac Cardiovasc Surg 1987;94:715-9
11.Rao PS. Transcatheter treatment of pulmonary stenosis and coarctation of the aorta: experience with percutaneous balloon dilatation. Br Heart J 1986;56:250-8
12. Suarez de Lezo J, Fernandez R, Sancho M, et al. Percutaneous transluminal angioplasty for aortic isthmic coarctation in infancy. Am J Cardiol 1984;54:1147-9
13. Fontes VF, Esteves CA, Brago SLM, et al. lt is valid to dilate native aortic coarctation with a balloon catheter. Internat J Cardiol 1990;27;311-6
14. Tynan M, Finley JP, Fontes V, Hess J, Kan J. Balloon angioplasty for treatment of native coarctation: results of Valvuloplasty and Angioplasty of Congenital Anomalies Registry. Am J Cardiol 1990;65:790-2
15. Hellenbrand WE, Allen HD, Golinko RJ, et al. Balloon angioplasty of aortic recoarctation: results of Valvuloplasty and Angioplasty of Congenital Anomalies Registry. Am J Cardiol 1990;65:793-7
16. Rao PS. Balloon angioplasty of native coarctations (Letter). Am J Cardiol 1990;66:1401
17. Rao PS. Which aortic coarctations should we balloon dilate? (Editorial). Am Heart J 1989; 117:987-9
18. Rao PS. Should balloon angioplasty be used instead of surgery for native aortic coarctation? (Editorial). Br Heart J 1995;74:578-9
19. Rao PS. Should balloon angioplasty be used as a treatment of choice for native aortic coarctations? J Invasive Cardiol 1996;8:301-3
20. Rao PS, Chopra PS. Role of balloon angioplasty in the treatment of aortic coarctation. Ann Thorac Surg 1991;52-621-31
21. Rao PS. Balloon angioplasty of native aortic coarctations. In Rao PS (ed). Transcatheter Therapy in Pediatric Cardiology, New York: Wiley-Liss, 1993; pp. 153-196
22. Rao PS, Galal 0, Smith PN, Wilson AD, Five-to-nine year follow-up results of balloon angioplasty of native aortic coarctation in infants and children, J Am Coll Cardiol 1996;27:262-70
23. Reddington AN, Booth P, Shore DF, Rigby MI. Primary balloon dilatation of coarctation in neonates. Br Heart J 1990;64:277-81
24. Rao PS, Galal 0, Wilson AD. Feasibility and effectiveness of repeat balloon dilatation of restenosed obstruction following previous balloon valvuloplasty/angioplasty. Am Heart J 1996;132:403-7
25. Munich LL, Beekman RH, Rocchini AP, et al. Surgical repair is safe and effective after unsuccessful balloon angioplasty of native coarctation of the aorta, J Am Coll Cardiol 1992; 19:389-93
26. Lababidi Z. Percutaneous balloon coarctation angioplasty: long-term results. J Intervent Cardiol 1992;5:57-62
27, Lee SY, Reddy SCB, Rao PS. Evaluation of superficial femoral artery compromise and limb growth retardation following transfemoral artery balloon dilatations. Circulation 1997;95:974-80
28. Rao PS, Wilson AD, Brazy J. Transumbilical balloon coarctation angioplasty in a neonate with critical aortic coarctation. Am Heart J 1992; 124.:1622-4
29. Alyousef S, Khan A, Nihill M, Lababidi Z, Mullins C. Perkutane transvenose antegrade ballonangioplastic bei aortenisthmusstenose. Herz 1988; 13:36-40
30. Cooper RS, Ritter SB, Rothe WB, Chen CK, Griepp R, Golinko RJ. Angioplasty for coarctation of the aorta: long-term results. Circulation 1987;75:600-4
31. Bromberg BI, Beekman RH, Rocchini AP, Snider AR, Bank, ER, Heidelberger K, Rosenthal A. Aortic aneurysm after patch aortoplasty repair of coarctation: a prospective analysis of prevalence, screening tests and risks. J Am Coll Cardiol 1989; 14:734-41
32. Pinzon JL, Burrows PE, Benson LN, et al. Repair of coarctation of the aorta in children, postoperative morphology. Radiol 1991; 180: 199-203
33. Parks WJ, Ngo TD, Plauth WH, Jr., et al. Incidence of aneurysm formation after Darron patch aortoplasty repair of coarctation of the aorta: long-term results and assessment utilizing magnetic resonance angiography with three-dimensional surface rendering. J Am Coll Cardiol 1995;26:266-71
34. Shaddy RE, Boucek MM, Strurtvant JE, et al. Comparison of angioplasty and surgery for unoperated coarctation of the aorta. Circulation 1993;87:793-9
35. Rao PS, Chopra PS, Kosak R, et al. Surgical venous balloon therapy for aortic coarctation in infants < 3 months old. J Am Coll Cardiol 1994;23:1479-83
36. Salahuddin N, Wilson AD, Rao PS, An unusual presentation of coarctation of the aorta in infancy: role of balloon angioplasty in the critically ill infant. Am Heart J 1991; 122:1772~5

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