Pediatric Aortic Valve Insufficiency Treatment & Management

Updated: Jan 04, 2016
  • Author: Mohsen Saidinejad, MD, MPH, MBA; Chief Editor: Stuart Berger, MD  more...
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Treatment

Medical Care

See the list below:

  • Currently, acute severe aortic valve insufficiency cannot be managed by medication alone. [4] Symptomatic patients with normal left ventricle (LV) function may be safely treated with aggressive medical management with variable results, but no present data have provided for a significant role of medical therapy for patients with acute severe aortic valve insufficiency.

  • In severe aortic valve insufficiency, the excess in afterload increases burden on the left side of the heart. Theoretically, any medication that can reduce afterload could be expected to improve left ventricular function and decrease regurgitant backflow from the aorta. This would provide a temporizing measure by which surgical intervention can be postponed. One study showed that the use of nifedipine in asymptomatic patients with severe aortic regurgitation who had normal LV function could delay the need for surgery by 2-3 years. [5] This result may also be expected with the use of similar vasodilating agents.

  • As a general rule, medical management of chronic aortic valve insufficiency is related to the severity of regurgitation, symptoms, LV function, and size, as follows:

    • Moderate aortic valve insufficiency with no change in cardiac size

    • Mild or moderate aortic valve insufficiency with only minimally increased cardiac size

    • Severe aortic valve insufficiency with volume overload

    • Severe aortic valve insufficiency with LV dysfunction

    • Severe aortic valve insufficiency with significant LV hypertrophy

    • Mild aortic valve insufficiency with no change in cardiac size

      • Therapy not required

      • Echocardiographic follow-up required every 12 months, looking for change in chamber size or cardiac function

      • Antibiotic prophylaxis for endocarditis

    • Moderate aortic valve insufficiency with slight limitation of cardiac reserve

      • No vigorous athletic activity

      • No isometric exercise

      • No therapy except endocarditis prophylaxis

      • Follow-up echocardiographic studies

    • Severe aortic valve insufficiency with LV dilation but normal LV systolic performance

      • Echocardiographic evaluation every 6 months

      • Vasodilators: With the exception of vasodilators, no data suggest that other medications are of long-term benefit hemodynamically or in terms of patient outcome. Vasodilating agents reduce afterload by improving stroke volume and subsequently reduce regurgitant volume in chronic severe AR. This reduces end-diastolic volume of the LV; therefore, wall stress and afterload is decreased, and LV function and size normalize.

      • No isometric exercise or school physical education activities

      • Digitalis glycosides

      • Other cardiac glycosides

    • Severe aortic valve insufficiency with symptoms and/or reduction in LV function

      • Surgical treatment

      • Aortic valve replacement

  • Other therapeutic modalities include the following:

    • Arrhythmias treated when present

    • Bradycardias treated when present

    • Possible infections treated

    • Possible role of nitroglycerin in management of angina

    • Intravenous hydralazine

    • Oral prazosin

    • Sublingual nifedipine

  • Cardiac catheterization may be indicated, if questions remain after evaluation with echo-Doppler, CT, and MRI, as follows:

    • In symptomatic patients with an ejection fraction less than 0.55 or an end-systolic LV dimension of 55 mm or higher (or, in Marfan syndrome, an aortic dimension of >4 cm), perform cardiac catheterization and angiography in anticipation of valve replacement surgery.

    • An indicator-dilution, thermodilution, or Fick technique is used for cardiac output measurement.

    • Retrograde left heart catheterization records coronary driving pressure, and LV angiocardiography evaluates the size of the LV, wall thickness, mitral valve function, patency of the coronary arteries, and diameters of the aortic root and ascending aorta.

    • Cine aortography with contrast material into the aortic root is used to measure the severity of AI, with calculation of regurgitant volume by subtraction of the net forward flow (ie, Fick method) from the angiographically determined total forward flow.

    • Possible complications include rupture of blood vessel, tachyarrhythmias, bradyarrhythmias, and vascular occlusion.

    • Postcatheterization complications include hemorrhage, vascular disruption after balloon dilation, pain, nausea, and vomiting. Other possible complications include arterial or venous obstruction by a thrombus or transient vasospasm.

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Surgical Care

With development of increasing severity in symptoms, aortic valve replacement should be considered, even if LV systolic performance appears well preserved. Surgery is also indicated in patients with severe aortic regurgitation and reproducible evidence of LV dysfunction at rest or extreme LV dilation. In asymptomatic patients, do not consider surgery on the basis of a single echocardiographic or radionuclide angiographic measurement.

When choosing surgical intervention, assess the patient's clinical stability for a major surgical procedure and sufficiently examine the risks and benefits. Deciding the appropriateness of surgical intervention may be difficult in a patient who has the immediate risk of surgical intervention with aortic valve replacement and risk of hemodynamic collapse without surgical intervention.

In symptomatic patients, surgical intervention is a more acceptable approach than attempting long-term medical therapy. The exception to this is symptomatic patients with normal LV systolic performance who are poor candidates for surgery because of additional cardiac or noncardiac risk factors.

  • Outcomes of surgical therapy

    • Surgical outcome tends to correspond to the degree of LV performance before surgery.

    • Persistent cardiomegaly is possible.

    • Worsening of LV function after valve placement may occur.

    • LV function improves greatly in persons whose LV systolic performance was adequate preoperatively.

  • Postoperative considerations

    • Focus on minimizing postoperative LV dysfunction and assessing ventricular size.

    • Short duration of preoperative ventricular dysfunction is associated with good postsurgical outcome.

    • Obtain close follow-up echocardiographic studies.

    • Use radionuclide ventriculography for follow-up assessments.

    • Evaluate ejection fraction and end-systolic volumes.

    • Evaluate LV volume overload during exertion as opposed to during rest.

  • Assessing surgically suitable candidates

    • Assess indices that are relatively load-independent, including end-systolic wall stress-Vcfc relationship.

    • Look for predictors of poor surgical outcome, including the following:

      • Patients with severe LV dysfunction

      • Prolonged ventricular dysfunction with decompensation

      • Ejection fraction less than 0.50 (may suggest need for surgical evaluation but is also associated with possibility of poor surgical outcome)

      • In adults, end-systolic diameter higher than 55 mm (may signify risk of LV dysfunction and death; however, no guidelines have been formulated for children)

  • Surgical correction

    • The focus is on correcting underlying problem and may involve the following:

      • Correction of the dilated aortic root with annuloplasty

      • Correction of aneurysmal dilation of the ascending aorta with excision and graft replacement and coronary artery reimplantation

      • Correction of prolapsed aortic leaflet

      • Correction of perforated leaflet of a valve with a pericardial patch

      • Placement of prosthetic valve

    • The Ross procedure is one current method of pulmonary valve autotransplantation, although recent studies have begun to indicate the lack of long-term maintenance of the surgical site and re-emergence of aortic insufficiency within a few years after the procedure. [6, 7, 8] The Ross procedure continues to be a surgical option in patients with aortic valve insufficiency, but frequent and early re-evaluation following the operation is warranted.

      • First pioneered by Ross in 1967, the Ross procedure is a complicated procedure that has proponents and opponents. It uses the patient's pulmonary valve and root to replace a diseased aortic valve. The procedure involves harvesting and transposing the pulmonary valve into the aortic position, either as a complete root or as a freehand valve in the native aortic root.

      • One study found that, following the Ross procedure, overall survival rate into adulthood is excellent, and the need for valve replacement is rare. [9] However, the use of a allograft is associated with questions regarding durability and late function.

      • Onetudy compared the clinical and hemodynamic outcome after an aortic valve replacement with a pulmonary valve autograft (using the Ross procedure) with an allograft valve in children. [10] This study reported that both procedures showed excellent clinical results over the following years. It also reported that the Ross procedure showed a better hemodynamic status, suggesting that, over the long run, it may be the better tolerated procedure.

      • In complete pulmonary root transposition, coronary artery reimplantation is needed. Then, a pulmonary homograft is placed in the position of the pulmonary root. Note that the durability of homografts is greater on the right side of the heart than the left; the hemodynamic stress on the right side of the heart is less than that on the left.

      • The pulmonary autotransplanted valve then begins to adapt to the hemodynamic burden of the aortic position without need for anticoagulation. Risk of thromboembolism and endocarditis is thought to be minimal. Nevertheless, reoperation may be necessary in 15-20% of patients within 20 years, usually for replacement of the pulmonary homograft.

      • Elkins et al have studied this procedure in children and concluded that it is the operation of choice for children requiring an aortic valve replacement. [11] The low surgical mortality rate and late morbidity associated with the Ross procedure and lack of a need for anticoagulation make this procedure desirable. Furthermore, Elkins et al noted that the Ross procedure allows a growing child to have a near-normal lifestyle, with a limited risk of reoperation for autograft valve or homograft valve failure.

      • Some concerns about the Ross procedure have been raised. The operation is thought to be highly complex and associated with greater risk for complication than isolated aortic valve replacement or root replacement. Another concern is that few cardiothoracic surgeons have enough experience with this procedure in children to be able to offer it with a risk comparable to conventional valve replacement. In addition, the Ross procedure is not indicated in patients with connective tissue disorders, such as Marfan syndrome or primary aneurysm disease with secondary aortic valve incompetence, because aneurysmal changes may also be expected to develop in the new pulmonary transplant in the aortic position.

      • Elkins et al examined mid and late results of autograft valve durability, patient survival, and valve-related morbidity related to the Ross procedure. [9] A retrospective review of patients (age range, 3 d to 17 y) who underwent the Ross procedure between November 1986 and May 2001 was performed using medical records and patient contacts.

      • The most recent echocardiographic evaluation was reviewed for autograft valve and homograft valve function. [9] The operative mortality rate was noted to be 4.5% (8 cases in 178 patients), with 3 late deaths (2 were non–valve-related) for an actuarial survival rate of 92% ± 3% at 12 years. Autograft valve degeneration requiring reoperation or severe insufficiency of autograft valve or valve-related death was low, with the freedom from complication rate reaching 90% ± 4% at 12 years. Autograft valve degeneration was not affected by the technique of insertion (141 root replacement, 37 intra-aortic), aortic valve morphology (157 bicuspid or unicuspid, 26 tricuspid), or age at operation.

      • Autograft valve degeneration was worse in patients with a primary lesion of aortic valve insufficiency than in those with aortic stenosis (P = .03). [9] Autograft valve reoperation was required in 12 patients; autograft valve replacement was needed in 7. The actuarial freedom from autograft replacement was 93% ± 3% at 12 years. Homograft valve replacement was required in 7 patients, with 90% ± 4% actuarial freedom from replacement at 12 years. The study concluded that survival and freedom from aortic valve replacement are excellent in children. Homograft valve late function remains a concern, and efforts to improve homograft durability should be encouraged.

    • Many patients do extremely well after valve replacement. In children, the procedure seems to be well tolerated and successful.

    • Cross-sectional data of 112 patients who had a clinic visit and echocardiography at some point after a Ross procedure were reviewed. [12] Aortic valve insufficiency was the indication for the procedure in most (70.5%) patients, and aortic stenosis was an indication in others (9.8%). The male-to-female ratio was approximately 5:1. The study reported that late outcome for the Ross procedure was excellent with respect to survival and quality of life. On the other hand, physiologically, root dilatation, autograft regurgitation, and allograft stenosis increased in prevalence over time. The study suggested that even slight modifications of the procedure, annual echocardiographic evaluation, and early reintervention on the early and mild dilatation of the aortic root may improve the durability of an autologous pulmonary valve.

    • Currently, the main concern is the long-term performance of allograft. Recent literature has focused on the fact that, although the allograft has excellent performance and provides symptom-free results for several months and even years, the durability of the graft is still a concern. Better, more durable solutions may be required beyond the current lifespan of the grafts presently used, in order to avoid the need for a more dangerous regrafting at a later age.

    • One study published in 2002, presented a 13-year experience with allografts in 267 successive adult patients who underwent graft replacement. [13] The study noted that the range of graft survival was 12-23 years. The overall postoperative survival rate at 9 years was 73%. The study concluded that allograft durability is a potential significant problem.

    • LV function may or may not improve greatly; however, better techniques have allowed for a higher percentage of patients to experience an improvement in LV function.

    • The operative mortality rate for such operations is 4-10%, depending on institutional experiences.

    • A study by Kouchoukos et al raised concern about the long-term performance of the valve following the Ross procedure. [7] The study suggests that the progressive dilatation of the pulmonary graft may be a main cause of surgical failure and a reason for reoperation in patients who have undergone the Ross procedure with the root replacement technique. The study concluded that the long-term follow-up of patients who have had the Ross procedure with root replacement technique has an excellent survival rate and a low risk for thromboembolus and endocarditis. Although the prevalence of neoaortic valve regurgitation is low, the progressive increase in the diameter of the aortic root is a cause of reoperation. Thus, periodic echocardiographic evaluation of the site is recommended because of the ongoing risk of neoaortic valve regurgitation and the formation of aneurysms of the aortic root.

    • Another study by Pasquali et al examined the aortic root diameters 5 years after the Ross procedure and noted that the neoaortic root size increased at a statistically significant rate. [6] This further suggests that although the Ross operation is still considered a palliative procedure for aortic valve disease, over a median follow-up of nearly 5 years after the Ross procedure, neoaortic root size increased significantly out of proportion to somatic growth. The study also found a moderate or greater risk for aortic insufficiency. As many as 12% of patients required further intervention. This was an alarming finding, suggesting that much more frequent and early reassessment of the surgical site is warranted following the Ross procedure.

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Consultations

Management of aortic valve insufficiency in infants, children, and young adults is complex and generally should be supervised by a cardiologist.

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Diet

No diet restrictions are indicated.

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Activity

Patients with mild aortic valve insufficiency may continue to engage in regular activity.

Isometric exercise should be avoided in moderate or severe aortic valve insufficiency.

Competitive athletics should be avoided in all patients with severe aortic valve insufficiency.

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