Correspondence

Surgeons should provide minimally invasive approaches for the treatment of congenital heart disease

The basis for pursuing techniques for less invasive surgery on children with congenital heart disease is to reduce the known long-term morbidities of thoracotomy and sternotomy. In addition, rapid return to normal activities, reduced length of stay, and better pain control may be achieved. Several congenital lesions have been successfully treated with innovative minimally invasive techniques; however, further technique and technology development is required to accomplish repair of the more complex defects safely and effectively.

Beating atrial septal defect closure monitored by epicardial real-time three-dimensional echocardiography without cardiopulmonary bypass

BACKGROUND

We assessed the feasibility of beating atrial septal defect (ASD) closure monitored by real-time 3D echocardiography (RT3DE).

METHODS AND RESULTS

RT3DE was developed with prototype ultrasound equipment consisting of a high-speed 3D rendering unit with a frame rate of 5 to 10 frames/s. We also developed a prototype semiautomatic suture device and suture cutting system. In the experiment, 12 mongrel dogs were anesthetized, and after median sternotomy, the echo probe was applied directly to the surface of the right atrium. Three surgical maneuvers (balloon atrial septectomy, enlargement of the ASD, and ASD closure) were performed through the atrial port inserted into the right atrial appendage. The heart was then excised, and the area of the ASD measured by RT3DE was compared with its area measured directly. The ASD was successfully closed in all experimental animals except the first 2. Examination of the excised heart showed that none of the sutures were loose. The mean area of the ASD was 82.5+/-38.6 mm(2) when measured by RT3DE and 81.6+/-38.2 mm(2) when measured directly, and there was a significant correlation between the areas measured by RT3DE and those measured directly (echo measurements=1.007xdirect measurements+0.337; P<0.0001). A Bland-Altman analysis revealed close agreement between the results obtained by the 2 methods (7.807 mm(2) upper and -6.024 mm(2) lower limit of agreement).

CONCLUSIONS

Introduction of RT3DE, a semiautomatic suture device, and a suture cutting system made beating ASD closure without cardiopulmonary bypass possible.

Minimal-access surgery for congenital heart defects

Improved results with lower operative mortality and morbidity for corrective surgery for many congenital cardiac defects has stimulated a renewed interest in the use of surgical approaches other than a full midline sternotomy. In an effort to decrease pain and discomfort, shorten the recovery period, and improve the cosmetic result, several alternative approaches have been proposed and implemented, with varying results. Anterior thoracotomy in the inframammary area has been the most widely used incision and is most applicable to females patients past puberty, in whom the extent of breast tissue can be assessed more accurately. Complications with this approach including phrenic nerve injury and breast and chest wall deformities have been reported, although most reports describe satisfactory cosmetic results. We have used a midline approach limiting the incision over the xyphoid process either without a sternal incision (infants) or with division of the lower segment (patients younger than 3 to 4 years) with cephalad retraction to expose the heart and great vessels. From May 1996 to June 1997, 54 children had repair of a secundum-type atrial septal defect using a transxyphoid or ministernotomy approach. In 29, arterial cannulation was performed through the ascending aorta, and in 25 via the femoral artery. There were no instances in which conversion to full sternotomy was required, and complete repair with comparable ischemic and bypass time to full sternotomy was achieved in all patients. We have also used the same technique for repair of other congenital cardiac lesions, including ventricular septal defect and partial or complete atrioventricular canal defects, and in selected infants with tetralogy of Fallot. With this approach, cardioplegia for myocardial protection and left ventricular venting to prevent distention and to remove air from the heart can be used routinely. The adaptability of this technique to various cardiac defects and the ability to extend the incision if necessary make it an attractive alternative to other approaches for minimal-access cardiac surgery for congenital defects. Copyright 1998 by W.B. Saunders Company

Ventilation strategy for video-assisted thoracoscopic clipping of patent ductus arteriosus in children

Video-assisted endoscopic techniques have reduced operative trauma in adult thoracic and general surgery but its application in children with congenital heart disease has been limited. We report the use of video-assisted thoracoscopic (VAT) technique of clipping patent ductus arteriosus (PDA) in children. Forty patients with PDA were divided into two groups: during VAT surgery patients in group A [mean age=3.6 +/- 2.4 (SD) years] were managed with right main stem bronchial intubation and those in the group B [mean age=3.7 +/- 2.7 (SD) years] received low tidal volume-high frequency ventilation using a Siemens 900C ventilator. The mean oxygen saturation (SpO2) observed during the surgical intervention was significantly lower in group A (90%) compared to group B (96.8%) while the surgical convenience was not different. We conclude that a low tidal volume-high frequency ventilation is acceptable and safe in patients with PDA undergoing VATS.

Partial median sternotomy as a minimal access for the closure of subarterial ventricular septal defect. Feasibility of transpulmonary approach

BACKGROUND

Minimally invasive techniques in congenital heart surgery have evolved steadily over the past few years, but documentation in the literature is rare. The majority of reported techniques involve thoracoscopic approach and partial sternotomy. We have employed a lower partial sternotomy as a minimal-access procedure for the closure of subarterial ventricular septal defect, for situation where this approach would be unsuitable for adequate exposure of the pulmonary artery. The purpose of this study is to demonstrate the feasibility and safety of this technique and report its superior cosmetic result.

SUBJECTS AND METHODS

Beginning in 1997, we began approaching the closure of subarterial ventricular septal defect through a lower sternal split incision using a 6 to 10 cm skin opening, associated with a reversed L incision at the left second intercostal space. A total of consecutive 12 patients (6 male and 6 female) have been operated on using this approach. The patients ranged in age from 6 to 21 years (mean, 12.8 +/- 5.0 years). The straight cannula with stylet was used for aortic cannulation.

RESULTS

There was no mortality or morbidity, except for late pericardial effusion in 4 cases. The durations of cardiopulmonary bypass and aortic cross-clamping ranged from 94 to 206 (mean, 131 +/- 33) minutes and from 40 to 122 (mean, 70 +/- 26) minutes, respectively. Ten of 12 patients were extubated in the operating room, and no patient required blood transfusion. The postoperative hospital stay ranged from 8 to 21 (mean, 13.4 +/- 4.2) days. No patient developed deterioration of aortic regurgitation or residual ventricular septal defect.

CONCLUSIONS

Our experience demonstrates that the lower partial sternotomy for the closure of subarterial ventricular septal defect is technically feasible and can be used with excellent cosmetic results and safety. Although experience is limited and follow-up is relatively short, this less invasive surgical technique may become a beneficial option for the management of subarterial ventricular septal defect.

Current status and future directions of minimally invasive cardiac surgery

The impetus to reduce the trauma of surgery witnessed over the past decade in all fields of surgery has recently extended into the cardiac surgical arena; however, unlike other specialties, the invasiveness of cardiac surgery can be reduced by limiting the size of incisions and by avoiding cardiopulmonary bypass. This article reviews the rationale, clinical experience, and outcomes of the minimally invasive approaches to cardiac surgery that have evolved over the past 2 years and glimpses into the future of this rapidly evolving field.

Right parasternal minithoracotomy for repair of atrial septal defect

Various surgical approaches for repair of atrial septal defect (ASD) have recently been introduced for superior cosmetic and less invasive results. A technique for repair of isolated ASD through a small right parasternal minithoracotomy is described. In spite of the smaller incision, there is no need to use femoral cannulation or video-assisted endoscopy. This approach is simple, less invasive, and cosmetic. We believe that right parasternal minithoracotomy is a suitable alternative to a median sternotomy for ASD closure, especially in young male patients.

Minimally invasive right heart operations: techniques for bicaval occlusion and cardioplegia

Peripheral cardiopulmonary bypass with cardioplegia has facilitated minimally invasive coronary artery bypass grafting and mitral valve replacement. The cardiopulmonary bypass system was modified to allow bicaval occlusion for right heart operations. In 4 canine studies, three variants of bicaval cannulation techniques were successfully used for atrial septal defect repair via a right minithoracotomy.