The importance of localizing pulmonary veins in atrial septal defect closure!

The need for adequate preoperative diagnosis in the field of congenital heart surgery cannot be overemphasized. To this end many centers routinely use Intraoperative Trans-Esophageal Echocardiography (ITEE). Mayo clinic group in a study of 1002 congenital heart disease patients demonstrated that ITEE had major impact in 13.4% of cases defined as revealing any undetected pre or intaoperative information requiring an otherwise non-performed procedure during the surgery; however, the ASD secundum subset (67 cases) was the only primary diagnosis in this study that ITEE had zero major impact on and routine ITEE did not seem to be cost effective in this group[1]. In our experience also a comprehensive preoperative Trans-Thoracic Echocardiography (TTE) is considered adequate for delineation of simple cardiac defects such as ASD secundum unless the cardiologist is not satisfied with the quality of the study in which case preoperative TEE, cardiac MRI or ITEE is considered. In contrast to what was just mentioned the following case report serves as an example of inadequate TTE that failed to detect other major concomitant congenital heart defects accompanying an ASD secundum in an 8-year-old girl which had major impact on her operation.

This case report merits special consideration not only because of the very rare constellation of ASD, IIVC, Scimitar Syndrome, and anomalous systemic arterial supply of the lung, but also what the appropriate management should be while three of these four anomalies were discovered during the operation. It is not unheard-of for surgeons to come across new pathologies during the operation, but it is very unlikely for these new findings to change the nature of the procedure. In current practice TTE is considered adequate for the preoperative evaluation of ASD secundum and a detailed comprehensive echocardiography is expected to obviate the need for routine invasive diagnostic tests such as cardiac catheterization or even ITEE [1, 2]. Preoperative TTE should include evaluation of all pulmonary veins. Occasionally they are not visualized due to poor acoustic window; in which case preoperative TEE, cardiac MRI or ITEE should be considered if not routinely performed [3]. Subcostal view in TTE should delineate Scimitar syndrome [3] and IIVC with Azygos continuation should also be readily diagnosed from this window [3]. Unfortunately these pathologies were missed in the preoperative TTE and were first diagnosed during the surgery. After IIVC was discovered intraoperatively the subject was raised to abort the operation and perform cardiac catheterization to accurately describe concomitant cardiac anomalies before proceeding further, but we ultimately decided to continue the operation and not to impose the risk of another surgery. Several surgical techniques are available to correct scimitar syndrome which are best summarized in the paper by Gudjonsson et al [4]. We applied the surgical technique introduced by Shumacker and Judd, which includes transfer of the anomalous pulmonary vein to the right atrium adjacent to the ASD and then baffling its flow across towards the left atrium [5]. Several other congenital anomalies are also reported in patients with IIVC including visceral heterotaxy and polysplenia which were absent in our case [6].

Although preoperative TTE is considered adequate for the delineation of ASD secundum and its associated cardiac anomalies, this case report shows how an inadequate TTE can complicate the operation. Accordingly cardiologists should attempt to identify the site of drainage for all four pulmonary veins in the preoperative TTE and if there is any doubt about the quality of the study preoperative TEE, cardiac MRI or ITEE should be requested especially in centers where ITEE is not routinely performed for simple congenital heart surgeries such as ASD secundum closure.

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.