Superior Vena Cava Flap to Reroute Partial Anomalous Pulmonary Venous Connection

Introduction

Various surgical techniques have been reported for repairing partial anomalous pulmonary venous connection (PAPVC). ^{1 –4} However, there is no specific report considering cases of PAPVC in a reoperative setting. Residual PAPVC is occasionally found after previous atrial septal defect (ASD) closure. Because of adhesions in cases of redo surgery, most previously reported procedures are not applicable, especially in a case in which the anomalous pulmonary vein (PV) connects to the superior vena cava (SVC) at a considerable distance from the right atrium (RA). We present an alternative surgical technique to repair PAPVC to the higher (cephalad) segment of the SVC after a previous cardiac surgery.

Patient

A 46-year-old man was referred to our department with residual PAPVC after sinus venosus ASD closure during childhood. The initial operation was at age six years at another hospital; PAPVC had not been apparent either pre- or postoperatively. Residual PAPVC and right ventricular enlargement was found when he was referred for common atrial flutter at age 45 years. Cardiac computed tomography (CT) revealed PAPVC to the higher (cephalad) segment of the SVC (Figure 1). Catheter examination revealed Qp/Qs of 2.1.

OPEN IN VIEWER

Figure 1.

A and B, Preoperative CT. Yellow stars () show the anomalous pulmonary veins. CT indicates computed tomography (see full color figure in online version).

Operation was performed through repeat median sternotomy. Cardiopulmonary bypass (CPB) was established. After identifying an enlarged SVC due to anomalous pulmonary venous drainage, we decided to use an SVC flap for PV rerouting. Immediately after achieving cardioplegic arrest, we cautiously opened the SVC-RA junction obliquely to ensure that the sinus node was not injured. A small residual sinus venosus defect was found. The anterior SVC wall was cut to make a flap for rerouting the anomalous PVs (Figure 2B, F). The ASD was enlarged, and the exposed rough surface of the endocardium was epithelialized with interrupted stiches. The anomalous PVs were rerouted by suturing an SVC flap to the posterior wall of the SVC and the edges of the surgically enlarged ASD to direct pulmonary venous drainage into the left atrium (LA; Figure 2C). We confirmed that the PV pathway was greater than 15 mm in diameter using a Hegar dilator. The SVC-RA incision was extended caudally for concomitant RA ablation. Linear radiofrequency ablation of the cavotricuspid isthmus and of the line between RA scar and the inferior vena cava was performed (Figure 2H). An additional small expanded polytetrafluoroethylene patch was used to complete the rerouting of the PV to the LA (Figure 2C, D, G). Because of the lack of sufficient autologous pericardium, we selected bovine pericardium for systemic venous reconstruction (Figure 2D). Because the systemic venous route was slightly narrow, we added another bovine pericardium patch to augment the SVC-RA junction before weaning the patient off CPB (Figure 2E). Transesophageal echocardiography revealed no apparent stenosis in the reconstructed SVC and pulmonary venous pathways. Postoperative SVC pressure was 8 mm Hg. The patient experienced transient sinus node dysfunction immediately after the operation; his sinus rhythm subsequently recovered at the 20th postoperative day, and he was discharged on the 26th postoperative day. Postoperative CT (Figure 3) revealed no stenosis in the PV and systemic venous pathways. Three months of anticoagulation with Coumadin was prescribed to prevent thromboembolic events. Six months after the operation, the patient continues to have a sinus rhythm, without postoperative systemic or venous obstruction.

OPEN IN VIEWER

Figure 2.

Surgical schema (A-E, H) and intraoperative pictures (F, G). Yellow stars () show the SVC flap. Blue triangle () indicates the ePTFE patch used to complete the PV rerouting. Red square () shows the bovine pericardial patch. A, Lines of initial SVC-RA incision and SVC flap creation. B and F, Superior vena cava flap, PV orifices, and residual sinus venosus ASD. C, D, and G, Anterior SVC wall flap was sutured down to the posterior SVC wall to reroute anomalous PVs to the left atrium. A small patch of ePTFE was used to complete the PV rerouting. D and E, A bovine pericardium was used to reconstruct the SVC to the SVC-RA junction. H, Line of ablation was shown with blue line. Cavotricuspid isthmus (upper scheme) and the right atrium scar to the IVC (lower scheme). ASD indicates atrial septal defect; CS, coronary sinus; IVC, inferior vena cava; ePTFE, expanded polytetrafluoroethylene; PV, pulmonary vein; RA, right atrium; SVC, superior vena cava; SL, septal leaflet of the tricuspid valve (see full color figure in online version).

OPEN IN VIEWER

Figure 3.

A and B, Postoperative CT. Yellow stars () show the anomalous PVs. Anomalous PVs are rerouted to drain into the left atrium. CT indicates computed tomography; PV, pulmonary vein (see full color figure in online version).

Comment

We present an alternative surgical technique for PAPVC to the higher SVC after a previous cardiac surgery in a case in which the RA appendage and sufficient RA wall were unavailable. Recently, modification of the Warden procedure using right atrial pedicle flap and single pericardial patch for reconstruction of the systemic venous pathway has been reported as a safe and effective surgical option. ⁴ In the present case, we considered this technique first. However, the preoperative CT showed no apparent RA appendage and too small RA to harvest enough pedicle RA flap. Accordingly, caval division and graft interposition between the SVC and RA or double-patch repair using a large section of artificial material was the other surgical option.

Because the SVC was sufficiently wide, we decided to use its anterior wall as a flap for PV rerouting. A small Gore-Tex patch was added to complete the PV rerouting because the SVC wall was not sufficiently long for complete PV rerouting. In 1972, Puig-Massana et al reported a similar technique in which they created a tunnel that diverted the anomalous PV flow into the LA using a native vessel or RA wall. ¹ As the availability of autologous pericardium was limited in our patient, we selected the bovine pericardium for reconstructing the systemic venous route so that the duration of anticoagulation therapy would be limited. The merits of this procedure are as follows: (1) a lower risk of thrombosis in the left heart system compared to that for baffle rerouting with large artificial patches; (2) persistent anticoagulation therapy is not necessary; (3) cavoatrial stenosis is avoidable by using a sufficiently large patch to reconstruct the new systemic venous pathway; (4) limited risk of sinus node dysfunction because of avoidance of a long, complicated right atriotomy or sutures across the crista terminalis; and (5) overall procedural simplicity.

This technique is an alternative to the usual caval division technique for anomalous PV connections distant from the RA with cardiac adhesions. Our technique showed satisfactory results, as the patient continues to have a sinus rhythm, without postoperative systemic or pulmonary venous obstruction. As the follow-up time was limited, close follow-up will be required to assess the long-term outcome of this technique.