Ann Thorac Surg 1997;63:744-745
© 1997 The Society of Thoracic Surgeons
Invited Commentary
John E. Mayer, Jr, MD
Department of Cardiovascular Surgery The Children's Hospital 300 Longwood Ave Boston, MA 02115
See also page 741.
This report by DeLeon and co-workers reemphasizes the point that pulmonary venous obstruction is an important consideration in the management of total anomalous pulmonary venous connection to the coronary sinus. Embryologically, the coronary sinus is derived from the embryonic cardinal vein system, and there are connections between the venous drainage of the embryonic lung buds and the systemic veins prior to the development of the normal connections to the common pulmonary vein, which then merges with the posterior wall of the left atrium. In the usual case, these embryonic pulmonary venous to systemic venous connections disappear, but the presumptive mechanism for total anomalous pulmonary venous connection is persistence of the embryonic connections.
It has been my impression that obstruction is more likely to be present in total anomalous pulmonary venous connection to the coronary sinus when the connection between the pulmonary veins and the coronary sinus is more distant from the coronary sinus orifice, ie, there is a longer length of coronary sinus beyond the site where the pulmonary veins connect. In the experience of my colleagues and myself, the obstruction generally occurs at this connection point rather than in the areas where the coronary sinus has been "unroofed." The mechanisms responsible for the development of stenosis at this connection site are unknown, and the reasons why early pulmonary venous stenosis after repair is frequently associated with a progressive obliterative process in the more distal pulmonary venous system (as in patient 3 in the accompanying report) are equally unclear. However, it seems that when the initial repair results in an unobstructed pulmonary venous pathway, the incidence of this pulmonary venous obliterative process is low. For this reason, I would agree that the preoperative identification of patients who are at risk for the development of pulmonary venous obstruction is critical to their initial management.
The technique used primarily by DeLeon and associates in their fourth patient (in whom the diagnosis of obstruction was made preoperatively) and in the other 3 patients at reoperation where a direct connection was made between the common pulmonary vein and the posterior wall of the left atrium is virtually identical to the one I have used when the pulmonary vein–coronary sinus connection is more distant from the heart and is either already obstructed or is likely to develop obstruction postoperatively. A reasonable argument can be made for employing this technique in all cases of total anomalous pulmonary venous connection to the coronary sinus, and this is now my approach in most patients. However, the important biologic question that should be addressed is the mechanism for the progressive pulmonary venous obliteration, which is fatal in a high proportion of the patients in whom it develops. An increased understanding of the signaling between the endothelium and the remainder of the vein wall may provide additional insights into the prevention of and therapy for this process.
Related Article
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Recognition and Management of Obstructed Pulmonary Veins Draining to the Coronary Sinus
- Maryann M. DeLeon, Serafin Y. DeLeon, Patrick T. Roughneen, Timothy J. Bell, Dolores A. Vitullo, Frank Cetta, Lynn Lagamayo, and Elizabeth A. Fisher
Ann. Thorac. Surg. 1997 63: 741-744.
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