Totally robotic repair of atrioventricular septal defect in the adult

Patient 1 A 33 year-old lady who had detected heart murmur for 6 years presented with
recent onset of palpitation and chest discomfort. She was admitted in July 2011 and
trans-thoracic echocardiography (TTE) suggested an ostium primum atrial septal defect
(ASD) (2.2 cm in diameter) with left to right intracardiac shunt, and a 0.2 cm mitral
valve cleft with moderate mitral regurgitation (MR). The interventricular septum was
intact. The pulmonary artery pressure was 38 mmHg and mild tricuspid regurgitation
was present. She was diagnosed with partial AVSD.

Patient 2 A 24 year-old lady was admitted due to detected heart murmur for 5 years
in December 2014. TTE suggested an ostium primum ASD (1.2 cm) with mitral valve cleft
and moderate MR whilst a patent foramen ovale (PFO) (0.2 cm) and a perimembranous
ventricular septal defect (VSD) (0.3 cm) were also present with left to right shunt.
The left atrium was dilated (3.6 cm in diameter). The ventricles were normal with
LVEF of 76 %. She was diagnosed with intermediate AVSD and PFO.

Patient 3 A 27 year-old lady was admitted because of heart murmur detected 4 months
before in January 2015. TTE suggested a sucundum ASD (2 cm) co-existing with an ostia
primum ASD (2 cm) and a 1.1 cm mitral valve cleft, which caused left to right shunt
and moderate MR. The pulmonary artery pressure was 41 mmHg and mild tricuspid regurgitation
was seen. The right heart was dilated and the diameters of RA and RV were 4.6 cm and
4.3 cm respectively. The left heart was normal and LVEF was 58 %. The diagnosis was
partial AVSD and sucundum ASD.

All three patients had normal peripheral vasculatures confirmed by ultrasonic scan
and the informed consent was taken for totally robotic repair of AVSD before surgery.

During surgery, general anaesthesia was induced and CPB was set up through peripheral
vessels according to our protocol 2], 3]. After systemic heparinization, femoral arterial (17 F to 22 F) and venous (21 F
or 23 F) cannulation (Metronic, Minneapolis, Minn) was performed through a 2-cm transverse
incision at the right groin under the guidance of TEE. Bicaval venous drainage was
instituted through the jugular and femoral/inferior vena cava cannulas. The robotic
camera and instrument arms were inserted with a working port made in the right chest
(Fig. 1). The pericardium was opened and the aorta was cross clamped after CPB began. The
heart was arrested with single dose of antegrade cold HTK cardioplegic solution given
directly through anterior chest using a 14GA angiocatheter, and endoscopic snaring
of the vena cavae with umbilical cords was performed.

Fig. 1. a The set-up of robotic camera (b) and instrument arms (a, c, d) in the right chest of patient, with a 1.5 cm working port (e) at the fourth intercostal space. b The surgical incision wounds on the chest wall at 6-month follow-up of patient 1

Via right atriotomy, mitral valve was examined (Fig. 2a) and the cleft between the left superior and inferior leaflets was repaired using
three to four interrupted 4–0 Goretex sutures and saline injection test was performed
(Fig. 2b). Six to seven interrupted 4–0 pledgted Gore-Tex mattress sutures were placed along
the crest of interventricular septum from the right ventricular side (Fig. 2c). In one case where a small VSD co-existed, the mattress sutures were placed beneath
the lower margin of the VSD and brought directly through the crest of ventricular
septum for the primary closure of VSD. After measurement of the dimension between
the superior and inferior commissures was made, a Dacron patch was prepared according
to the shape and size of the ostium primum ASD. Then, the mattress sutures were brought
through the lower margin of the patch to secure it into the crest of ventricular septum,
either by knot tying pusher or Cor-Knotâ„¢ tying device (LSI Solutions, Victor, NY).
Then two 4–0 Gore-Tex running sutures were used to close the ASD from the upper and
lower commissures. The inferior suture was continued below the Thebesian valve to
avoid injury to the conduction tissue with the coronary sinus draining into the left
atrium. PFO or secundum ASD was closed separately. The right atriotomy was closed
with double layers of 4–0 Goretex running suture and CPB was weaned as routine.

Fig. 2. a A cleft between the left superior and inferior leaflets (black arrow) was examined and repaired through the osmium primum ASD (red arrow). b The saline injection showed a competent mitral valve after the repair by interrupted
4–0 Gore-Tex sutures. c The interrupted mattress sutures were placed along the crest of the ventricular septum
with the pledgets on the right ventricular aspect. d The primum ASD was closed with a Dacron patch with coronary sinus draining to left
atrium

Fig. 3. The postoperative TEE confirmed an intact septum without residual shunt (a) and competent mitral valve without regurgitation (b) after surgery

All three patients were off bypass easily. The total CPB time was 195 min, 128 min,
and 126 min for the first, second and the third patients, and aorta cross clamping
time was 126 min, 88 min and 80 min respectively. Intraoperative TEE excluded residual
shunt and regurgitation of mitral or tricuspid valves. The patients were ventilated
for 15 to 16 h in critical care ward and they all had an uneventful recovery postoperatively.
Postoperative TEE confirmed that the robotic repair of the defects was successful
with no intracardiac shunt or MR (Fig. 3). All patients were discharged within 1 week of surgery.