VSR is a life-threatening complication that occurs in 1–2 % of patients following acute transmural myocardial infarction . Surgical intervention is necessary because of the poor natural history of the entity, and several operative procedures have been reported in the literature.
Daggets et al. reported infarct resection and suturing of the right and left ventricles, including the ventricular septum . After 1990, the infarct exclusion technique with an incision of the left ventricular anterior free wall became popular and resulted in improved surgical results . The double patch technique via the right ventricle was reported to be an alternative approach for avoiding a left ventricular incision and providing a better surgical view with the help of intra-operative epicardial echo .
Although the outcomes of VSR repair have improved in recent years due to advancements in myocardial protection during surgery and intensive postoperative care, the mortality rate is still high (20–35 % for 30-day mortality and 55–63 % survival at 5 years) . The reported risk factors affecting the prognoses of VSRs include preoperative factors such as preoperative condition and posterior VSR and postoperative factors such as residual shunt flow and ventricular arrhythmia. Posterior VSRs, in particular, are technically difficult to repair because of their location. Suturing within the deep basal septum is complicated by the use of an apical ventricular incision.
VSR repair using a right atrial approach has been reported to overcome these difficulties [3, 4]. This approach provides a better view of the basal septal defect in case of posterior myocardial infarction. This approach is commonly used for congenital ventricular septal defects, but surgeons rarely use it for acquired VSRs.
The reason for this is that in VSR repair, the sutures must be placed in the fragile edge of the infarcted ventricular septum, and a large patch is sometimes needed to cover the defect. It is complicated to suture into the deep apex of the ventricular septum from the right atrium.
However, separating the tricuspid valve leaflet widely, not only the septal leaflet but also part of the posterior leaflet, improves the surgical view of the ventricular septum. We believe that concomitant tricuspid valve replacement will expand the indication of this technique.
In more serious cases, in which the infarct is too large and suturing of the deep apex area is necessary, an additional ventricular incision to the right atrial incision can be incorporated during surgery.
Posterior VSRs mainly caused by single-branch infarctions of the left circumflex artery or right coronary artery. When the middle to apex part of the ventricular septum is preserved with perfusion from the left anterior descending branch on preoperative echocardiography, the right atrial approach is suitable for performing repairs.
In the present case, the infarct was relatively small and the last branch of the left circumflex artery was occluded, making the right atrial approach mostly suitable for approaching the whole edge of the VSR.
In addition, the right atrial approach can improve many of the postoperative factors associated with poor prognoses. Remodeling of the infarcted myocardium and making a large incision in the ventricular free wall affect postoperative low ventricular function and ventricular arrhythmia. A large suture line and tight closure of the ventricle also reduce the residual ventricular volume and worsen ventricular diastolic function .
The right atrial approach eliminates the need for a ventricular incision and re-suturing, thus allowing the surviving myocardium and cardiac function to be preserved. In addition, the new onset of ventricular arrhythmia can be avoided.
Performing trans-catheter VSR repair with an occluding device is now possible. Currently, this less invasive technique is only recommended for small VSRs (<1.5 mm) and in subacute or chronic settings . Larger defects and friable surrounding myocardium increase the risk of the device migrating and some of the VSR being left behind, which can result in unfavorable prognoses.
Although surgeons must be cautious of possible postoperative tricuspid valve regurgitation and atrial arrhythmia, the right atrial approach is a useful method for posterior VSR repair.
In conclusion, we performed posterior postinfarction VSR repair via the right atrial approach. This approach is feasible for repairing posterior VSRs because it provides better exposure of the posterior septal defect than the trans-ventricular approach. Moreover, it allows postoperative ventricular function and ventricular arrhythmia to be avoided.