Sinus Venosus Atrial Septal Defect Repair Using a Beating Heart Technique

Sinus venosus atrial septal defect (SVASD) encompasses 4-11percent of all atrial septal defects. Anomalous pulmonary venous connection (APVC) of some or all pulmonary veins is frequently linked to SVASD (1). 

The routine technique used to repair such a defect involves using a single or double patch and requires arresting the heart with the use of a cardiopulmonary bypass (CPB). Beating heart surgery on CPB does not arrest the heart and, thus, is advantageous for preserving the myocardium and avoiding ischemic–reperfusion injury (2). 

Because the presence of the SVASD increases the chances of air embolisms, an aortic cross-clamp is applied with the use of continuous coronary perfusion. The SVASD with PAPVC can be repaired with either a single patch or a double patch, wherein the second patch is used to augment the superior vena cava (SVC) (3, 4). A single patch technique can be used if the SVC size is large and does not constrict on baffling the PAPVC into the left atrium. The goal of the repair is to divert the oxygenated blood from the anomalous pulmonary vein (usually the right superior pulmonary vein) into the left atrium and make sure the SVC canal is wide enough post repair (3). 

Step 1: Examine the External Cardiac Anatomy 

Before establishing a cardiopulmonary bypass, it is important to thoroughly examine the extracardiac anatomy and identify all normal and abnormal structures. In this case, the authors identified the anomalously draining right superior pulmonary vein (RSPV) and its distance from the superior vena cava (SVC)–right atrium (RA) junction. The SVC cannulation site was determined by the highest draining PV. SVC cannulation is to be done cranially to this site so that after inflow occlusion, this vein will be easily visible for baffle creation. 

Step 2: Establish Cardiopulmonary Bypass 

Cardiopulmonary bypass had been established by aortobicaval cannulation. In this case, there was a left SVC, which was cannulated separately. Alternatively, a cardiac sucker can be placed in the coronary sinus to drain the left SVC. Patent ductus arteriosus was ligated on bypass after decreasing the arterial flow. A coronary perfusion cannula was inserted into the ascending aorta for continuous coronary perfusion and surgery was performed at euthermia. The aorta was cross-clamped, and the aortic root was perfused with 4-5 mL/(kg /min) normothermic oxygenated blood. Electrocardiography was monitored for any ischemia alterations. 

Step 3: Examine Intracardiac Anatomy 

Both cavae were looped and snared. The right atrium was then opened laterally and extended across the SVC RA junction into the SVC until the highest draining PV is not visible. An angled suction tip was positioned in the coronary sinus ostium to keep the operating field bloodless. Retraction was minimized to avoid distorting the aortic root. The RA was retracted using stays and the intracardiac anatomy was thoroughly examined. The left atrium (LA) was examined for normal drainage of other pulmonary veins and the mitral valve was identified. The RA anatomy was then examined, and the coronary sinus and tricuspid valve were identified. The size of the SVASD and anomalously draining pulmonary veins were identified. The line of proposed suturing was marked in such a way as to baffle all the anomalously draining pulmonary veins into the left atrium. 

The azygous vein opening can be mistaken for another anomalous pulmonary vein, which can be avoided by tracing the opening laterally. The pulmonary vein can be traced to the hilum of the lung, whereas the azygous vein has a more posterior route. 

Step 4: Baffle Closure With Pericardial Patch 

An adequate-sized autologous pericardial patch was harvested and prepared. It is better to err on the side of keeping the patch larger than required and then tailoring it adequately as the patch is sutured in place. Suturing should begin at the cranial aspect of the highest draining pulmonary vein. 

Suturing then continued on the surgeon's side of the proposed suture line, including all the anomalously draining PVs, however, the lower margin of the SVASD was not reached. 

The patch was then tailored to keep the width of the patch adequate to create an adequate baffle. The other limb of the suture then continued on the far aspect to create a baffle from the PVs into the LA. 

Step 5: Deair Left Heart 

Before tying the two sutures together at the caudal end, the left heart was deaired by asking the anesthetist to ventilate the patient and the sutures were then tied. The patch suture line was inspected for any leaks. 

Step 6: Right Atrium Closed 

The right atrium was then closed, either primarily or by using a second patch to augment the SVC-RA junction if there is a doubt about the adequacy of the size of the SVC-RA opening. 

The absence of air in the left ventricle was confirmed by transesophageal echocardiography before opening the aortic cross-clamp. 

Outcome and Discussion  

Beating heart surgery can be done safely for atrial septal defects and for sinus venosus atrial septal defects. By avoiding cardiac arrest, the myocardium can be preserved in the highest possible way and ischemic–reperfusion injury can be avoided. This method is easy and reproducible and gives the best results (4). 

References

1. Attenhofer Jost CH, Connolly HM, Danielson GK, Bailey KR, Schaff H V, Shen WK, et al. Sinus venosus atrial septal defect: long-term postoperative outcome for 115 patients. Circulation. 2005 Sep 27;112(13):1953–8.
2. Pendse N, Gupta S, Geelani MA, Minhas HS, Agarwal S, Tomar A, et al. Repair of atrial septal defects on the perfused beating heart. Tex Heart Inst J. 2009;36(5):425–7.
3. Iyer AP, Somanrema K, Pathak S, Manjunath PY, Pradhan S, Krishnan S. Comparative study of single- and double-patch techniques for sinus venosus atrial septal defect with partial anomalous pulmonary venous connection. J Thorac Cardiovasc Surg. 2007 Mar;133(3):656–9.
4. Okonta KE, Tamatey M. Is double or single patch for sinus venosus atrial septal defect repair the better option in prevention of postoperative venous obstruction? Interact Cardiovasc Thorac Surg. 2012 Nov;15(5):900–3.

Disclaimer

The information and views presented on CTSNet.org represent the views of the authors and contributors of the material and not of CTSNet. Please review our full disclaimer page here.