CASE HISTORY
A 70-year-old Chinese gentleman with atrial septal defect (ASD), tricuspid regurgitation (TR) and atrial fibrillation (AF) of 1.5 years duration, presented with symptoms of dyspnoea (NYHA II-III) and fatigue on minimal exertion despite optimal medical therapy. Past medical history included hypertension and chronic kidney disease. Examination findings revealed bipedal oedema, hepatomegaly and fine basal crepitations bilaterally. Chest x-ray showed cardiomegaly and pronounced pulmonary vasculature. Trans-oesophageal echocardiogram (TOE) demonstrated a 3cm large ASD with left to right shunt (Qp:Qs 2:3), severely dilated and moderately impaired right ventricle (RV), pulmonary artery systolic pressure 54mmHg, mild mitral regurgitation, dilated left atrium (LA) and preserved left ventricular (LV) ejection fraction (EF 55%).
He underwent minimally invasive MAZE, left atrial appendage (LAA) obliteration, patch closure of ASD and bioprosthetic tricuspid valve replacement. Access was via a 5cm long right thoracotomy in the 4th intercostal space. Cardiopulmonary bypass (CPB) was established via cannulation of the right common femoral vein (24 Fr venous cannula - Edwards Lifesciences, Irvine, CA), the right internal jugular vein (18 Fr Optisite cannula - Edwards Lifesciences, Irvine, CA) and the right common femoral artery (22 Fr EOPA cannula – Medtronic Inc, Minneapolis, MN, USA). After initiation of CPB (nasal temperature of 34 degrees centigrade), venae cavae were snared, Chitwood aortic cross clamp applied, 1L of Del Nido cardioplegia was given antegradely down the aortic root. Operative field was flooded with carbon dioxide. The right, dilated and thick-walled, atrium was opened revealing a large ASD with deficient superior rim. Tricuspid valve annulus was normal with thickened, fused and calcified anterior and posterior TV leaflets.
Right pulmonary vein isolation using bipolar radiofrequency ablation device (Cardioblate®, Medtronic Inc, Minneapolis, MN, USA) was performed. LA MAZE lesion sets were carried out through the large ASD using unipolar radiofrequency ablation device (Cardioblate®, Medtronic Inc, Minneapolis, MN, USA) (Fig 1). LAA was obliterated with double-layered continuous 4-0 prolene suture. ASD was next closed with bovine pericardial patch using continuous single-layered 4/0 prolene with a 5x5mm cruciate fenestration made centrally. In view of severe rheumatic changes, fibrotic, calcified anterior and posterior TV leaflets were excised. A 33mm St Jude Epic (St Jude Medical, Minneapolis, MN) porcine bioprosthesis was implanted with interrupted pledgetted 2/0 ethibond mattressed sutures. The patient was separated from CPB uneventfully with minimal inotropes in sinus rhythm. CPB time was 175 minutes and aortic crossclamp time was 106 minutes. Post-repair TOE confirmed complete obliteration of the LAA, presence of an intact pericardial patch with central fenestration, and a well-seated, normally functioning tricuspid bioprosthesis without paravalvular leak.
Postoperatively the patient remained in sinus rhythm (Fig. 2) and made an uneventful recovery, he stayed in ICU for 24 hours and was discharged home 4 days after his operation. At 1-year follow up he was doing well being asymptomatic (NYHA Class I) in sinus rhythm. Transthoracic echocardiogram (TTE) showed no residual shunt, a well-functioning tricuspid valve with mean gradient of 3.9mmHg, mild RV impairment with moderate RV dilatation and good LV function.