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.