**10. Management**

#### **10.1 Medical management**

Patients with complete defects present early with signs and symptoms of pulmonary over circulation such as tachypnea, increased work of breathing. In the neonatal period, when the pulmonary vascular resistance decreases, they require diuretics to help with pulmonary congestion and control heart failure along with optimizing nutrition. Occasionally they require afterload reducing agents if there is significant AV valve regurgitation and rarely inotropes. If heart failure or failure to thrive persists despite maximizing medical management, they would be referred for surgery. Based on the corrected gestational age, weight, type of atrioventricular septal defect and associated anomalies, surgical options vary which will be discussed below. As mentioned earlier, patients with partial atrioventricular septal defects usually show symptoms in childhood.

#### **10.2 Surgical management**

The goals of the surgery are to close the septal defect(s), repair the AV valve, construct two separate and competent AV valves, and avoid injury to conduction tissue.


Palliation with main pulmonary artery band (PAB) is performed in babies less than 5 Kg who failed medical management. In the recent era, complete repair is done even in this weight range. Palliation is considered in patients who are premature,

## *DOI: http://dx.doi.org/10.5772/intechopen.105615 Atrioventricular Septal Defects*

those deemed ineligible for definitive repair or with other co-morbidities. A recent study showed that PAB in complete AVSDs as a bridge to biventricular repair has similar survival as those for primary biventricular repair [28].

• Surgical Correction

Patients with complete AVSDs frequently require surgical repair in early infancy with a median age of 3.6 months at the time of repair [29]. Surgical repair is achieved by singe-patch, modified single-patch (Australian/Nunn) or two-patch techniques. A meta-analysis, which compared modified single-patch and two patch techniques showed no significant difference between two groups, but modified single-patch performed when there is small VSD had shorter cardiopulmonary bypass and aortic cross-clamp time [30]. Several other studies showed similar findings [31, 32–35]. The main advantages of the two-patch technique are maintaining planar alignment of AV valves, lower chances of narrowing of LVOT, not compromising ventricular volumes and preserving the integrity of bridging leaflets [36]. In the Pediatric Heart Network (PHN) study, earlier complete repair showed increased resource utilization with longer intensive care unit stay but no association with incidence of residual VSD or significant left AV valve regurgitation at six months of age (**Figure 12**). Moderate or greater left AV valve regurgitation was found in 22% at six months with the strongest predictor being moderate or greater left AV valve regurgitation at one month [32].

#### **Figure 12.**

*A, B: Intra-operative transesophageal echocardiogram, color compare deep transgastric view of left AV valve. A. Pre-operative image showing moderate regurgitation. B. Postoperative after left AVV repair. Note cleft is completely closed without any regurgitation. C. Transthoracic apical 4-chamber view of another patient with severe left AVV regurgitation in multiple jets.*

In the majority of the cases, cleft was closed, 93% in this study [37], it was partially closed, or left open in remaining cases.

Associated anomalies like patent ductus arteriosus, double orifice left AV valve parachute left AV valve should be addressed. Patients with complete AVSDs and tetralogy of Fallot associated with Down syndrome may need initial palliation with systemic to pulmonary artery shunt or right ventricular outflow tract (RVOT) stent placement and full repair at a later age. In a retrospective study [38], RVOT stenting showed a significant increase in median Z-score for both branch pulmonary arteries at a median follow-up of 255 days. Four patients out of 26 patients died during follow- up period, but none after the initial intervention. Another meta-analysis found no significant difference in the 6-year survival between staged palliation and primary repair, with higher rate of reintervention for RVOT who underwent staged repair [39].

In patients with partial and transitional AVSDs, there has been controversy regarding the age of surgical correction. A PHN study in 2010, showed good results at a median age of 1.8 years, with left AV valve regurgitation being most common and more frequently in children repaired after 4 years of age [12, 40, 41]. One patient out of 87 died in the hospital. Another review showed excellent results at median age of 1.5 years with LV outflow tract obstruction being most common reason for reoperation at their center [42]. Several other studies showed good long-term outcomes with 30-day and 5-, 10-, 20-, and 40-year survivals at 98%, 94%, 93%, 87%, and 76%, respectively. Approximately 3% of the patients in the Mayo group required permanent pacemaker [40, 41]. A minimally invasive right axillary approach has also been performed with good results in partial AVSD patients [43].

2.Unbalanced atrioventricular septal defects

Surgical techniques in patients with unbalanced AVSDs include single ventricle palliation, biventricular repair and 1.5 ventricular repair.

• Single Ventricle Palliation

Patients with severely hypoplastic right/left ventricle would be managed using staged single ventricle palliation. Initially, they are palliated with PAB and later undergo bidirectional Glenn around four to six months of age, if the pulmonary artery pressures are favorable. Around 2 to 3 years of age, extracardiac Fontan completion with or without fenestration is performed [44].

• One and half or bi-ventricular repair (BVR)

There are no clear selection criteria to stratify patients into either single or biventricular pathways. Several factors are taken into consideration such as hypoplastic ventricle end-diastolic volume (EDV) of >30 mL/m2 , normal ventricular function, adequate AV valve size and function, and low end-diastolic pressures on cardiac catheterization [45].

In select patients with right ventricular dominant AVSD, a staged left ventricular recruitment approach is considered, especially in patients with trisomy 21. It includes ASD closure or restriction, without VSD closure, septation of the common AV valve and banding of the main pulmonary artery [45, 46]. This strategy allows

*DOI: http://dx.doi.org/10.5772/intechopen.105615 Atrioventricular Septal Defects*

rehabilitation of the left ventricle. With this approach, patient would not be committed at an early age to either a single or bi-ventricular approach and it would give an opportunity to monitor for LV growth [45].

On the other hand, in patients with LV dominant AVSD with inadequate RV size, one and a half ventricular repair has been proposed with primary AVSD repair along with a bidirectional Glenn procedure [47]. This would allow growth of the hypoplastic right ventricle for future biventricular conversion. In some institutions, routine 3-D printing is done for all complex AVSD for pre-surgical planning which permitted biventricular repair in some patients who were previously deemed to be candidates for single ventricle palliation [48, 49].
