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.