Ann Thorac Surg 2004;78:727-729
© 2004 The Society of Thoracic Surgeons
How to do it
Total extracardiac cavopulmonary connection: an alternative technique of fenestration
Manoj Purohit, Mcha,
Marco Ricci, MDa,
Marco Pozzi, MDa*
a Department of Paediatric Cardiac Cardiology, Royal Liverpool Children's NHS Trust, Liverpool, United Kingdom
Accepted for publication April 8, 2003.
* Address reprint requests to Dr Pozzi, Department of Paediatric Cardiac Surgery, Royal Liverpool Children's NHS Trust, Liverpool L12 2AP, UK
e-mail: mpozzi76{at}hotmail.com
 |
Abstract
|
|---|
Fenestrating an extracardiac conduit used for total cavopulmonary connection normally requires an additional incision on the right-sided atrium and is time consuming. Herein we describe an alternative technique that may be used to facilitate this process, which consists of creating the fenestration by using part of the atrial incision resulting from the disconnection of the inferior vena cava from the right atrium. The advantages of this technique are avoidance of an extra incision and suture line on the atrium, and the ease of construction. This may be especially useful in patients with heterotaxy syndromes with mesocardia or dextrocardia, in whom the atrial mass is displaced posteriorly and can be difficult to reach. Closure of the fenestration can be easily performed at a later stage in the cardiac catheterization laboratory by using a septal occluding device.
|
Introduction
|
|---|
Total cavopulmonary connection by using an extracardiac conduit has been recently popularized in the management of a variety of cardiac anomalies that result in a functional univentricular heart. Since its original description [1], this technique has undergone several modifications in an attempt to widen its applicability and improve results [2–4]. Among others, the creation of a fenestration between systemic and pulmonary venous circulations has been used with increasing frequency to reduce postoperative morbidity and early mortality after total cavopulmonary connection [2, 4]. A few methods to accomplish this goal have been described in the literature, in the setting of both intracardiac and extracardiac Fontan operations [4–6]. However, creating a fenestration in the more recently introduced extracardiac variant normally requires an additional atrial incision and suture line. Also, this may be difficult and time consuming especially in patients with heterotaxy syndromes and mesocardia or dextrocardia, in whom the atrial mass is often rotated posteriorly and the right-sided atrium is difficult to expose.
The aim of this article is to describe an alternative technique of fenestration when performing a total cavopulmonary connection with an extracardiac conduit, which facilitates the procedure and avoids additional incisions on the atrium.
|
Technique
|
|---|
After sternal re-entry is accomplished, the heart, the great vessels, and the previous superior cavopulmonary anastomosis are dissected and exposed. If the lower portion of the pericardium has not been previously divided, the inferior surface of heart and inferior vena cava may be relatively free from adhesions. The inferior vena cava is dissected from the diaphragm as low as possible. After aortic cannulation, both superior and inferior vena cava are cannulated by using right-angled, metal tip venous cannulaes. Cardiopulmonary bypass is then established while the heart is kept beating. Cardiopulmonary bypass is managed by maintaining normothermia and full systemic perfusion throughout the procedure. The aortic root may be vented if needed, although in our experience this maneuver is generally not necessary, as none of the cardiac chambers is entered at any stage.
After a snare is placed around the superior vena cava, the pulmonary arteries are further dissected, and reconstructed as necessary. At this stage, the main pulmonary artery may have to be divided, depending on whether or not it was left connected to the heart as an additional source of pulmonary blood flow.
An adequately sized polytetrafluoroethylene (PTFE) conduit, generally 18 or 20 mm in diameter, is then chosen to complete the extracardiac rerouting from the inferior vena cava to the right pulmonary artery. Although the anastomotic sequence can be altered according to personal preference, we routinely begin by connecting the extracardiac conduit to the right pulmonary artery (Fig 1A). This strategy may facilitate exposure of this area, reducing the risk of pulmonary artery distortion. Also, it may improve visualization when the main pulmonary artery, or its bifurcation, are incorporated in the anastomosis, as these structures are often located behind a voluminous ascending aorta.
View larger version (38K):
[in this window]
[in a new window]
|
Fig 1. (A) The polytetrafluoroethylene (PTFE) extracardiac conduit is first connected to the right pulmonary artery. (B) The inferior vena cava is divided at the junction with the right atrium. The incision is partially closed with running 5-0 polypropylene, leaving the upper aspect unsutured and encircled by a purse-string. This area will be used for the fenestration. (C) The fenestration is constructed between the PTFE conduit and the right atrium. A Castaneda clamp is used to prevent bleeding from the atrium and air embolism. (D) The conduit is connected to the inferior vena cava, while the fenestration remains controlled by the snare. As the anastomosis is completed, air from the PTFE conduit is carefully removed, and the purse-string around the fenestration may be released.
|
|
After this anastomosis is completed by using a running 5-0 polypropylene suture, the PTFE graft is clamped, and the snare on the superior vena cava may be released. At this stage, the conduit is tailored to the appropriate length. The inferior vena cava is controlled by a snare placed just above the diaphragm. A vascular clamp is applied at the inferior vena cava–right atrial junction (Fig 1B), ensuring not to obstruct the coronary sinus. The atrium is then transacted, leaving a generous cuff of atrial tissue on the inferior vena cava side.
As the vascular clamp placed on the atrium could slip if the atrium is divided at once, we routinely transect the atrium only partially, leaving the distal 6 to 8 mm intact and still connected to the inferior vena cava. At this stage, we begin oversewing the atrium before transecting it completely. This technical detail allows to overcome the problem of a less than perfect occlusion of the clamp at its distal end, which could lead to severe bleeding or massive air embolism. The atrial incision is closed only partially with a double layer of 5-0 polypropylene continuous suture, as depicted in Figure 1B, leaving the upper portion of the incision unsutured for approximately 1 cm. This opening at the upper end of the incision, which will be used for the fenestration, is encircled with a 5-0 polypropylene purse-string (Fig 1B). The purse-string is tightened, and the vascular clamp on the atrium is released. By using a 4-mm aortic punch, an opening is created on the side of the conduit (Fig 1C). The appropriate site to fenestrate the graft is conveniently chosen after filling the heart. To prevent air embolism, a Castaneda vascular clamp is applied on the atrium where the fenestration is to be constructed, and the snare is released (Fig 1C). The fenestration is obtained by suturing the atrial incision to the 4-mm hole made in the PTFE conduit with running 6-0 polypropylene, as illustrated in Figure 1C. Small, full-thickness bites are used both on the atrium and the conduit, so as to obtain precise edge-to-edge approximation.
Lastly, the Castaneda clamp is removed and the fenestration is kept closed by the purse-string. Then the PTFE conduit is connected to the inferior vena cava so as to complete the total cavopulmonary connection (Fig 1D). Once all the anastomoses are completed, the air from the conduit is carefully removed, still maintaining the fenestration closed. After the removal of air, the purse-string around the fenestration is released, and the fenestration opened. One can then decide to either leave the purse-string in place to obtain an adjustable communication or to remove it, in which case the fenestration can be occluded at a later time in the catheterization laboratory.
|
Comment
|
|---|
Extracardiac cavopulmonary connection is being used with increasing frequency because it avoids cardioplegic arrest and it is applicable to a variety of cardiac anomalies [3, 6]. In addition, this technique provides ideal fluid dynamics, minimizes flow-related energy dissipation within the cavopulmonary conduit, and eliminates extensive suturing on the atrium [6]. However, in contrast to other intracardiac techniques of cavopulmonary connection, in which a fenestration can be simply created by making a hole in the "lateral tunnel" baffle or by leaving a gap in the suture line, fenestrating an extracardiac conduit may be cumbersome. It involves either a direct anastomosis between a thick PTFE conduit and the right-sided atrial wall, or the interposition of a second, smaller prosthetic graft. Regardless of the technique used, creating such fenestrations generally requires an additional incision and suture line on the atrium. Also, in some situations exposing the lateral wall of the right-sided atrium may be difficult, as is often the case in patients with heterotaxy syndromes associated with mesocardia or dextrocardia.
The technique described herein has been used in over 20 patients undergoing total extracardiac cavopulmonary connection for various cardiac anomalies. In our experience, it is highly reproducible and easily applicable to a variety of anatomic conditions. Main advantages are the technical ease, the elimination of an additional incision and suture line on the atrium, the avoidance of additional prosthetic material, and the versatility in the presence of a right-sided atrium difficult to expose. In addition, although our experience with off-pump total cavo-pulmonary connection is limited, we believe there are no contraindications to using the same technique in this setting.
With regard to closure of the fenestration, in our experience transcatheter closure can be readily obtained by using an Amplatzer septal occluder, a device employed routinely to close defects in the atrial septum. The device is deployed to occlude the fenestration, which lies away from other important structures such as the coronary sinus. In our experience, there have been no complications directly related to the construction of this type of fenestration, or to its transcatheter closure.
|
References
|
|---|
- Marcelletti C., Corno A., Giannico S., Marino B. Inferior vena cava-pulmonary artery extracardiac conduit. A new form of right heart bypass. J Thorac Cardiovasc Surg 1990;100:228-232.[Abstract]
- Lemler M.S., Scott W.A., Leonard S.R., Stromberg D., Ramaciotti C. Fenestration improves clinical outcome of the Fontan procedure: a prospective, randomized study. Circulation 2002;105:207-212.[Abstract/Free Full Text]
- Amodeo A., Galetti L., Marianeschi S., et al. Extracardiac Fontan operation for complex cardiac anomalies: seven years' experience. J Thorac Cardiovasc Surg 1997;114:1020-1031.[Abstract/Free Full Text]
- Black M.D., van Son J.A.M., Haas G.S. Extracardiac Fontan with adjustable communication. Ann Thorac Surg 1995;60:716-718.[Abstract/Free Full Text]
- Airan B., Sharma R., Choudhary S.K., Mohanty S.R., Bhan A. Univentricular repair: is routine fenestration justified?. Ann Thorac Surg 2000;69:1900-1906.[Abstract/Free Full Text]
- Petrossian E., Thompson L.D., Hanley F.L. Extracardiac conduit variation of the Fontan procedure. In: Karp R.B., Laks H., Wechsler A.S., eds. Advances in Cardiac Surgery. St. Louis: Mosby, 2000:175-198.
Top
Abstract
Introduction
