Pediatric Complete Atrioventricular Septal Defects Treatment & Management

Updated: Mar 02, 2016
  • Author: Michael D Pettersen, MD; Chief Editor: Syamasundar Rao Patnana, MD  more...
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Treatment

Medical Care

Although their effectiveness in complete atrioventricular septal defect (AVSD) has been questioned, diuretics, digoxin, and ACE inhibitors have all been used to alleviate tachypnea and failure to thrive.

In many medical centers, the surgical mortality rate at age 2-3 months is 5% or less. Therefore, unless symptoms are dramatically relived, medical treatment for children with symptoms of congestive heart failure (CHF) is not pursued for more than a few weeks before definitive repair.

Some children who have survived surgical repair of complete atrioventricular septal defect (AVSD) require prolonged hospitalization. Causes are multifactorial but may include sepsis, pulmonary hypertension, residual left-to-right shunts through ventricular septal defects (VSDs), or significant atrioventricular valve insufficiency.

Associated noncardiac problems, including feeding difficulties, renal insufficiency, or pulmonary insufficiency, may require ongoing management and delayed discharge.

Postoperative medications range from none to many of the medications used to treat CHF discussed in the Medication section.

Almost every child who has survived surgical repair of complete atrioventricular septal defect has some abnormality of an atrioventricular valve.

Antibiotic prophylaxis is recommended for patients during the first 6 months after complete repair and for patients who have a residual intracardiac shunt associated with prosthetic patch material.

Consultations

Given the complexity of atrioventricular septal defect, a multidisciplinary team is usually required. This could include pediatric cardiologists, pediatric cardiothoracic surgeons, pediatricians, neonatologists, and pediatric intensivists, as well as a nurse coordinator and supportive ancillary staff

Additional consultants might include a geneticist for genetic counseling and a nutritionist.

Transfer

Patients with complete atrioventricular septal defect should be transferred to an institution skilled in successfully treating patients with complex congenital heart disease.

Diet and activity

A high-energy diet is needed because cardiac shunting results in high metabolic demands. Even at 125 kcal/kg/d, children still may not appropriately gain weight. Some children have such high metabolic demands that extraordinary energy intake, exceeding 150 kcal/kg/d, is necessary for growth.

Pulmonary edema can lead to tachypnea that makes oral intake of nourishment too difficult. A nasogastric tube may be needed in severe cases of congestive heart failure (CHF) with failure to thrive.

After the patient recovers from surgery, normal daily activities should be allowed.

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Surgical Care

Treatment for a complete atrioventricular septal defect is surgical.

Single-stage complete repair is currently preferred, but occasional cases of refractory CHF in a low-birth-weight infant may be palliated with the placement of a pulmonary artery band.

Some patients with complete atrioventricular septal defect have additional muscular ventricular septal defects (VSDs). Banding of the pulmonary artery may alleviate their CHF for 6-12 months, during which time the VSDs may spontaneously close and thus simplify eventual complete repair.

The surgical mortality rate should be low. In a published review of surgical outcomes of 363 patients with atrioventricular septal defects who were treated between 1982 and 1995, the early mortality rate was 10.3%, and the 10-year survival rate was 83%. [34]

The Pediatric Heart Network Investigators recently published a multicenter observational study on the contemporary results after repair of complete atrioventricular septal defect. In this series of 120 children, in-hospital and 6-month mortality rates were 2.5% and 4%, respectively. The incidence of residual septal defects and the degree of left atrioventricular valve regurgitation was independent of repair type, presence of trisomy 21, and age of operation, although younger age of operation was associated with a longer hospital stay. [17]

Another study, also from the Pediatric Heart Network Investigators, assessed the influence of atrial VSD subtype on outcomes after repair. Preoperatively, transitional patients showed the highest prevalence of moderate or severe left atrioventricular valve regurgitation (LAVVR). In data obtained 1 and 6 months post AVSD repair, the results noted that complete atrial VSD and canal-type VSD patients showed the highest prevalence of trisomy 21 and were younger, had lower weight-for-age z scores, and had more associated cardiac defects. Annuloplasty was similar among all subtypes, while complete atrial VSD showed a longer duration of ventilation and hospitalization. At 6 months, weight-for-age z scores improved and improvement was similar in all subtypes. [35]

A pulmonary artery band, placed on the main pulmonary artery by means of a small lateral or anterior thoracotomy incision, obviates cardiopulmonary bypass in a premature neonate or small infant. However, it has the risks of distorting the origins of the branch pulmonary arteries if it migrates and of complicating the eventual definitive surgery if it erodes through the media and intima. Pulmonary artery banding is best used, when deemed necessary, for only a few months in a patient who then undergo complete intracardiac repair and pulmonary artery band takedown.

A major aspect of atrioventricular septal defect repair involves creating a competent mitral valve. A pericardial patch can be used for this augmentation and for tricuspid valve repair. Repair is occasionally done with 2 patches: a pericardial patch for the atrial septal defect and a polytetrafluoroethylene patch (Gore-Tex patch; W.L. Gore & Associates, Inc, Newark, DE) for the VSD, with routine closure of the mitral valve cleft. The 2-patch technique with routine cleft closure and atrial septal incision may lower the incidence of residual mitral regurgitation.

Ten Harkel et al reported intermediate follow-up results in patients who underwent surgical repair of atrioventricular septal defects. [36] During a mean follow-up of 66 months, 19% had severe mitral valve regurgitation, and 9% required reoperation. Of note, 13% of patients with severe mitral valve regurgitation in the immediate postoperative period had significantly improved mitral valve function. For this reason, the authors cautioned against reoperation in the early postoperative period unless it is absolutely necessary. The study from the Pediatric Heart Network Investigators reported the incidence of moderate or greater mitral valve regurgitation to be 22% at 6 months. [17]

Left ventricular outflow tract obstruction (LVOTO) is the second most common cause for reoperation after atrioventricular septal defect repair. Five years postoperatively, 10% of patients required reoperation for LVOTO. [37] This rises to 24% among patients who demonstrated LVOTO at the time of initial repair. [38] LVOTO after repair of atrioventricular septal defect is complex and multifactorial, and the ideal surgical approach remains to be defined.

Patent ductus arteriosus (PDA) ligation, removal of a previously placed pulmonary artery band, repair of stenosis of a pulmonary arterial branch, or relief of aortic arch obstruction are also frequently performed at the time of complete repair. Recent data suggest that children with atrioventricular septal defects and Down syndrome have a prognosis better than that of children with the same cardiac lesion but not Down syndrome.

Residual atrioventricular valve insufficiency or stenosis is a major determinant of long-term outcome.

Total circular annuloplasty is a simple procedure to help reduce atrioventricular valve regurgitation, although most patients with severe atrioventricular valve insufficiency or stenosis require more complex mitral valvuloplasty techniques. The need for mitral-valve replacement is not rare over the course of long-term follow-up but is ideally delayed until an adult-size prosthetic valve can be implanted.

Atrioventricular septal defect may be associated with other surgical conditions, including subaortic stenosis, coarctation of the aorta, tetralogy of Fallot (TOF), and total anomalous pulmonary venous return. Each associated lesion may complicate complete repair and make it difficult to achieve a good hemodynamic result. In addition, these defects may add potential risk over follow-up (eg, recoarctation after coarctation of the aorta repair or pulmonary insufficiency after repair of TOF).

Surgically induced atrioventricular block is a known complication of atrioventricular septal defect repair. Permanent pacing is required if atrioventricular conduction does not return postoperatively.

For complex cardiac lesions involving an unbalanced atrioventricular septal defect, total cavopulmonary connection, otherwise known as a Fontan operation, may be indicated.

In the presence of TOF, an aortic monocusp is used to compensate for deficient right atrioventricular valve tissue. Right-dominant, unbalanced biventricular repair can be successfully completed in patients with mild LV hypoplasia. However, careful preoperative evaluation of the adequacy of the LV to support the systemic circulation is imperative.

De Oliveira et al reported their experience with 2-ventricular repair of patients with unbalanced atrioventricular septal defect and small right ventricles (RVs). Patients with a small RV had a high mortality rate, with an 87% 10-year survival, compared with a 100% survival rate in surgical patients with balanced atrioventricular septal defect. Although a median sternotomy is the usual surgical approach, the thoracotomy approach was safely used for common atrioventricular canal repair in some centers.

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Long-Term Monitoring

As needed, outpatient care for nonsurgical patients with atrioventricular septal defect should focus on providing adequate nutrition and medications to lessen congestive heat failure (CHF) symptoms.

Outpatient care should prepare the child for surgical intervention at the age appropriate for the institution where the operation will be performed.

Postoperative outpatient care depends on any clinically significant residual problems.

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