Introduction
Atrial septal defects (ASDs) are one of the most common congenital
anomalies. While a small variety of ASDs may close naturally, many
necessitate intervention. Percutaneous closure using the Amplatzer
device is possible for secundum ASDs, which retain a sufficient rim of
tissue around the defect. Conversely, the surgical closure of ASD is
traditionally accomplished through a median sternotomy, cardiopulmonary
bypass (CPB) and cardioplegic arrest of the heart; however, the
unpleasant cosmetic outcome and possible complications of median
sternotomy are occasionally distressing to patients [8]. It would
therefore be prudent for surgeons to compare the initial postoperative
outcomes of patients who have undergone ASD closure via right
minithoracotomy, under direct vision, with the same outcomes of those
who have undergone ASD closure via the standard median sternotomy to
better understand the safety and effectiveness of both surgical
procedures [5].
Rationale
Atrial septal defect closure is a surgical procedure often performed at
the National Heart Foundation Hospital & Research Institute (NHFH &
RI) in Dhaka, Bangladesh. For almost all ASD closure cases, the median
sternotomy has been the favoured method; in fact, using the right
minithoracotomy to close ASDs is not a routine practice here. It is
rather an innovative way to reform cardiac surgery in this country
considering cardiac surgeons’ increasing interest in performing
minimally invasive procedures, in addition to the rising patient demand
for less-invasive procedures.
Hypothesis
Atrial septal defect closure using the right minithoracotomy, under
direct vision, is predicted to have less postoperative morbidity
compared to the standard median sternotomy.
Methods
This comparative study was conducted at the NHFH & RI in Dhaka,
Bangladesh, between July 2014 and June 2016. It involved all patients
who underwent isolated ASD closures using either the right
minithoracotomy or the standard median sternotomy.
Ethical issues
The ethical review committee of the NHFH & RI approved this project.
All participants were verbally informed of the study’s design and
purpose, as well as their right to withdraw from the study at any time
for any reason. Written consent was obtained from each participant.
Sampling technique
Purposive and convenience sampling were used for all consecutive
patients who fulfilled the enrolment criteria.
Selection criteria
Patients who were undergoing isolated surgical ASD closure for the first
time were included in the study. Patients exhibiting the following
characteristics were excluded from the study: decreased left ventricular
ejection fraction (<30%) and those associated with other
congenital heart disease.
For the purposes of this study, 44 patients undergoing isolated surgical
ASD closure were divided into two equal groups of 22 participants to be
studied. The sample size of both groups was determined using the
following formula:
n=2σ²/∆²(zα+zβ)²
Since n = 22, the total sample size was 44 (22 × 2 = 44).
Operative technique
At the NHFH & RI, the current preferred method for minimally invasive
ASD closure involves the fourth intercostal space minithoracotomy
incision, which provides improved cosmesis with a direct view from a
lateral perspective into the right atrium and interatrial septum. For
each participant who underwent this procedure, a skin incision of 6–8
cm was made over the chosen interspace, and the intercostal incision was
extended beyond the skin incision, which allows a retractor to spread
the ribs while minimizing the risk of breaking them. A 3-cm incision was
also made just underneath the right inguinal fold; the anterior femoral
artery and vein were thus exposed with minimal dissection. After a full
dose of heparin a femoral arterial cannula was advanced into the
proximal iliac artery using the Seldinger technique: a femoral venous
cannula was passed over a guidewire to the right atrium under TEE
visualization. Once cannulation had been completed, the patient was
placed on CPB. When the pericardium was opened anterior to the phrenic
nerve, multiple pericardial retention sutures were placed anteriorly and
posteriorly to retract and define the access to Sondergaard’s groove and
obtain access to the aorta. A CP cannula was then inserted into the
ascending aorta. Furthermore, a Cosgrove flexible aortic cross-clamp
(see Figure 1) was applied, after which cardioplegic arrest of heart was
achieved and Sondergaard’s groove was opened.