Closure of atrial septal defects without cardiopulmonary bypass: the sandwich operation

Intraoperative customized double-patch device with twin sutures for multiple muscular septal defects

OBJECTIVES

Closure of multiple muscular ventricular septal defects (VSDs) remains a challenge because of anatomical complexity.

METHODS

We mapped all the VSDs using en face reconstruction of the right ventricular septal surface through echocardiography and then performed an 'Intraoperative Customized Double-Patch Device' technique to surgically close them in 39 patients (male:female = 25:14). The median age of the patients was 6 months (2 months-10 years), and mean weight was 5.98 ± 4.21 kg. A patch of polytetrafluoroethylene was placed on the left ventricular side of the defect and another on the right ventricular side, and they were anchored to each other using 2 polypropylene sutures. Residual shunts were evaluated using intraoperative echocardiography and measurements of right atrial-pulmonary arterial saturation were taken in all patients.

RESULTS

The distribution of muscular VSDs was as follows: anterior muscular 12, posterior muscular 18, mid-muscular 11 and apical 9. The associated lesions included perimembranous VSD (n = 28), tetralogy of Fallot (n = 6), double-outlet right ventricle (n = 2) and supramitral membrane (n = 2). Mean clamp time and bypass time were 93 ± 19 min and 147 ± 26 min, respectively. Mean hospital stay was 11 ± 3.39 days with no in-hospital mortality. Five patients with significant residual shunts needed concomitant PA banding. All patients remained in New York Heart Association Class I. There was either no residual shunt (n = 3) or trivial shunt (n = 2) among the banded patients. All patients remained symptom-free and continued to thrive well at the most recent follow-up (3.48 ± 1.51 years).

CONCLUSIONS

Muscular VSDs can be mapped through en face reconstruction and closed using intraoperative customized double-patch device technique in a variety of situations with satisfactory immediate and short-term results.

Robotics and imaging in congenital heart surgery

The initial success seen in adult cardiac surgery with the application of available robotic systems has not been realized as broadly in pediatric cardiac surgery. The main obstacles include extended set-up time and complexity of the procedures, as well as the large size of the instruments with respect to the size of the child. Moreover, while the main advantage of robotic systems is the ability to minimize incision size, for intracardiac repairs, cardiopulmonary bypass is still required. Catheter-based interventions, on the other hand, have expanded rapidly in both application as well as the complexity of procedures and lesions being treated. However, despite the development of sophisticated devices, robotic systems to aid catheter procedures have not been commonly applied in children. In this article, we describe new catheter-like robotic delivery platforms, which facilitate safe navigation and enable complex repairs, such as tissue approximation and fixation, and tissue removal, inside the beating heart. Additional features including the tracking of rapidly moving tissue targets and novel imaging approaches are described, along with a discussion of future prospects for steerable robotic systems.

Three-dimensional echo-guided beating heart surgery without cardiopulmonary bypass: atrial septal defect closure in a swine model

OBJECTIVE

In this study, we tested 3 techniques of atrial septal defect closure under real-time 3-dimensional echocardiography guidance in a swine model.

METHODS

The operations were conducted under the sole guidance of a modified real-time 3-dimensional echocardiography guidance system with a x4 matrix transducer (Sonos 7500, Philips Medical Systems, Andover, Mass). Eighteen swine were anesthetized, and after median sternotomy, the echo probe was applied directly to the surface of the right atrium. To create an atrial septal defect, balloon atrial septostomy and atrial septal defect enlargement were performed. Subsequently, 3 different techniques of atrial septal defect closure were attempted: group I, direct suture closure; group II, closure of the atrial septal defect using the Amplatzer device (AGA Medical Corp, Golden Valley, Minn); and group III, patch closure of the atrial septal defect (n = 6 each).

RESULTS

Real-time 3-dimensional echocardiography guidance provided sufficient spatial resolution and a satisfactory frame rate to provide a "virtual surgeon's view" of the relevant anatomy during the entire procedure. All atrial septal defects were enlarged, and the mean final size was 8.5 +/- 1.8 mm. Atrial septal defect closure was successfully accomplished with all the 3 surgical techniques examined. In groups I and III, the needles (1-3 sutures) and staples (6-12 staples) penetrated the tissue and patch material consistently, whereas in group III, the Amplatzer atrial septal defect device was easily deployed. There was no incident device/staple embolization or air introduction. Neither intraoperative 2-dimensional color Doppler echocardiography nor postmortem macro-evaluation revealed any residual shunts.

CONCLUSIONS

Beating heart atrial septal defect closure under real-time 3-dimensional echocardiographic guidance is feasible and, unlike catheter-based devices, applicable for any type of secundum atrial septal defect.

Robotic pediatric cardiac surgery: Present and future perspectives

Advances in robotic technology and imaging systems have enabled the broad application of minimally invasive techniques in cardiac surgery, including coronary artery bypass grafting and mitral valve repair in adults. In pediatric cardiac surgery, however, current robotic systems have been used primarily to facilitate thoracoscopic pediatric procedures on extracardiac lesions, such as ligation of patent ductus and division of vascular rings. The use of smaller instruments with sophisticated robotic wrists may make it possible to perform more complex extracardiac procedures even in young infants. Additionally, future technological improvements, including incorporation of tactile feedback, instrument tracking, and intracardiac imaging (such as real-time 3-dimensional echocardiography), may enable intracardiac robotic surgery to be performed in children. This article reviews the current and potential future applications of pediatric robotic surgery and the developmental work required to enable performance of these procedures, along with an overview of the problems associated with the use of current robotic surgical systems in children.