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Ann Thorac Surg 1998;65:765-767
© 1998 The Society of Thoracic Surgeons

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Original Articles: Cardiovascular

Minimally Invasive Repair of Atrial Septal Defects

Division of Cardiovascular Surgery, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada
Division of Cardiology, The Hospital for Sick Children and The University of Toronto, Toronto, Ontario, Canada

Accepted for publication August 30, 1997.

Dr Black, Division of Cardiovascular Surgery, The Hospital for Sick Children, 555 University Ave, Toronto, Ont, Canada M5G 1X8 (e-mail: michael.black@mailhub.sickkids.on.ca).

	Abstract

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Background. Minimally invasive pediatric cardiac surgical techniques continue to evolve and remain challenged by technologic advances in percutaneous devices developed to treat congenital heart disease exclusive of cardiopulmonary bypass. Public tenacity for "incisionless" operations, however, must remain balanced scrupulously against the collective safety of the surgical procedure.

Methods. Twenty-three pediatric patients underwent repair of atrial septal defects through a partial sternal split and a limited skin incision (5 to 7 cm) at our institution between July 1995 and October 1996.

Results. The average age of the patients was 6 years and 2 months (range, 19 months to 15 years) and the average weight was 23.3 kg (range, 11.3 to 61.7 kg). The average bypass time was 35 minutes (range, 19 to 81 minutes). Fourteen patients had a single dose of blood cardioplegia administered, whereas 9 had ventricular fibrillation electrically induced. Twenty-two patients had ostium secundum defects and 1 had a sinus venosus defect. The average length of the hospital stay was 3.6 days (range, 3 to 6 days). There were no operative or late deaths.

Conclusions. Modifications of this technique continue to evolve as an effective cosmetic alternative to submammary and thoracotomy approaches. Advantages of this modification include excellent cosmetic results in all age groups and the concomitant security and familiarity of mediastinal access and full sternotomy when required.

	Introduction

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Public pressure for "incisionless" operations and improved cosmetic results must be balanced scrupulously against the overall safety of the operation. Minimally invasive surgical techniques continue to evolve and to be challenged by technologic advances in percutaneous devices developed to treat atrial defects. At present, surgical closure still provides a safer and more effective result in the treatment of atrial septal defects [1]. We review a viable cosmetic alternative for the repair of atrial defects that has the additional benefits of surgical safety and complete access to the mediastinum when necessary. Currently, most atrial septal defects referred for operation at our institution are large. Smaller variants have been randomized to a device closure protocol.

	Surgical Technique

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After the induction of anesthesia and the placement of appropriate monitoring lines, the patient is prepared and draped in a supine position.

A limited skin incision (approximately 5 to 7 cm in greatest length) is made, starting from the most caudad extent of the body of the sternum (exclusive of the xiphoid process) and proceeding cephalad. The subcutaneous tissue is mobilized partially to prevent undue tension on the soft tissues. The lower part of the sternal body is exposed and the sternum is partially split up to the lower part of the manubrium sterni. An undersized sternal retractor is used to reflect the sternal halves gradually. Rapid retraction must be avoided to prevent sternal fracture. The thymus gland is reflected cephalad and, after pericardiotomy and the placement of traction sutures, a portion is harvested (pericardium) and treated in glutaraldehyde for possible future use as a patch. The ascending aorta is cannulated only after the right atrial pursestring suture has been placed. Traction on this suture provides complete exposure of the ascending aorta. The pulmonary artery is dissected free of the aorta, providing adequate access for a partial occluding clamp that is used in aortic cannulation.

Cannulation of the inferior vena cava varies depending on the location of the atrial septal defect. Variations can include direct inferior vena cava cannulation with a right-angled cannula and cannulation through the right atrium (for a low-lying atrial septal defect). The superior vena cava is cannulated through the right atrium (in the absence of a sinus venosus defect) with a straight venous cannula (Fig 1).

View larger version (1K): [in this window] [in a new window]   Intraoperative photograph demonstrating the exposure obtained through the ministernotomy incision. The aortic cannula is seen at the most cephalad aspect of the field. Cardiopulmonary bypass is initiated through a straight venous cannula placed within the right atrial appendage. The cardiac decompression thus obtained allows superior visualization of the inferior vena cava for cannulation with a right-angled cannula. The straight cannula then is placed selectively within the superior vena cava. Note that the incision is centered over the entire right atrium.

A right atriotomy is made and the atrial septal defect is located. Suture or autologous pericardial patch closure is performed.

Before the atrial septum is closed, careful removal of air from the left side of the heart is carried out. After full rewarming, the patient is weaned from bypass followed by a brief period of hemoconcentration. Protamine sulfate is administered and closure is commenced in a routine manner. Steri-Strips provide adequate skin coverage (Fig 2). A single mediastinal tube is inserted and temporary pacing wires are secured when necessary (ie, in the presence of a sinus venosus defect or after the occurrence of atrial dysrhythmias).

View larger version (1K): [in this window] [in a new window]   Postoperative photograph demonstrating the extent of the ministernotomy incision, tube thoracostomy, and pacing wire placement in a patient with a sinus venosus atrial septal defect.

	Results

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The average hospital stay was 3.6 days (range, 3 to 6 days). The only in-hospital morbidity occurred in an asymptomatic boy who was found to have a moderate postoperative pericardial effusion. Evacuation was performed on the third postoperative day. He was discharged 4 days after his initial admission to the hospital (ie, his discharge was delayed by 1 day).

	Comment

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The median sternotomy long has been accepted as providing superior access to cardiac structures [6][7][8]. Why, then, should we diverge from success and accept alternatives that may reduce the safety of the surgical procedure? Probably because the cosmetic disadvantages of the median sternotomy are so obvious—a large and visible scar that remains a permanent reminder of an otherwise low-risk procedure. Safety remains a cardinal feature of this modified technique.

Children and young adults who undergo cardiac procedures typically have maldevelopment of the osseous chest wall because of alterations in the size and position of the underlying cardiac chambers. Several alternatives are currently available for accessing the thoracic cage and the underlying mediastinal structures. All the approaches have their own inherent flaws.

Pediatric patients who undergo thoracotomy must contend with possible future breast and pectoral muscle maldevelopment. Ipsilateral breast maldevelopment can occur in approximately 7.4% of patients, with periareolar numbness or hypoesthesia in 38.8% [9]. Pain and postthoracotomy skeletal muscle dysfunction are common [1] and remain the chief drawback of this approach. In addition, postoperative complications such as atelectasis, right phrenic palsy, and rib fractures occur at a low, but consistent, frequency [9].

The submammary incision (extended transverse submammary incision with vertical sternal split) [10] may be accompanied by the development of hematoma, seroma, and nipple/breast anesthesias in as many as 10% to 15% of women who are operated on through this incision. Breast malalignment also has been reported. In prepubescent girls, abnormal shape and size can occur during breast development. Breast tissue in both male and female infants does not reside solely beneath the nipple-areola complex [11][12]. Cadaveric examination has revealed breast tissue peripheral to the areolar border by as much as 1.5 cm. Obviously, this tissue is susceptible to both the surgical incision and future scar formation.

The recognition of long-term breast and pectoral muscle maldevelopment after anterolateral or posterolateral thoracotomy in pediatric patients has spurred the search for alternatives to or refinements of standard incisions. Although elaborate devices have been constructed to create mechanical traction to enhance exposure of the superior mediastinum [1][13][14] during a partial median sternotomy, we deliberately have avoided such contraptions and found them unnecessary. We also have avoided the complete mobilization of subcutaneous tissue from the suprasternal notch to the xiphoid process [14].

Mobilization of the subcutaneous tissues (with our modification) from the xiphoid process to the manubrium sterni remains limited. Rapid deployment of the sternal retractor must be avoided to prevent both undue skin tension (resulting in a tear) and an undesired sternal fracture. The ministernotomy incision has been used successfully in children 15 years of age, without sternal fracture (sternal flexibility remains intact). This approach is applicable to older and larger patients, with similar cosmetic results. Undersized defibrillator paddles and a sternal retractor must be available to simplify the procedure, especially in older children.

Complete visualization of the extreme cephalad mediastinal structures may be restricted, but critical visualization of the right atrium and aorta remain unhampered once the right atrial appendage is retracted caudad. Groin cannulation (femoral arterial), with its inherent disadvantages, can be avoided in all cases.

The ministernotomy incision continues to provide exceptional access to all cardiac structures, especially for cannulation and removal of air, without the inherent cosmetic disadvantages of its historically related median sternotomy incision.

	Addendum

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Since July 1996, this minimally invasive technique has been used successfully in the repair of perimembranous ventricular septal defects, ostium primum atrial septal defects, and atrioventricular valve abnormalities.

	References

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1. Levinson MM, Dewhurst T, Han MT, Fooks G, Fonger J. Cosmetic minimally invasive surgical closure of a patent foramen ovale. Report and surgical technique. In: The Heart Surgery Forum. http://www.hsforum.com/HeartSurgery/Directories/Articles/L/LevinsonMM/MISASD/1996-12451.hsf. Oct 15, 1996.
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12. Dehner LP The integumentary system. Section XIV (42) Breast. In: Kissane JM, ed. Pathology of infancy and childhood. St. Louis: Mosby, 1975:1172-1194.
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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Michael D. Black Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Black, M. D. Articles by Freedom, R. M. Search for Related Content PubMed PubMed Citation Articles by Black, M. D. Articles by Freedom, R. M.