Explantation of the Heart for Resection of Primary Cardiac Tumors can be Avoided by Partial Ex Situ Heart Surgery

We have read with interest the recent publication by Hoffmeier et al. concerning ex situ resection of large primary cardiac tumors [1]. The authors of this article report two patients with large tumors involving the posterior wall of the left atrium and the atrial roof, respectively [2]. In both cases, the heart was explanted and the tumor was resected ex situ followed by cardiac autotransplantation. Both patients survived the procedure, but one patient required twelve hours of extracorporeal membrane oxygenation support after the operation due to the long cardiac arrest time of 149 min. A total bypass time of 330 minutes was reported. The authors conclude that since radical resection of a malignant heart tumor is the most important determinant for relief of symptoms and long-term survival, complete resection of a large tumor can be much more easily performed after explantation of the heart, especially when posterior left atrial structures are involved.

We agree with the authors’ therapeutic strategy of complete resection of malignant heart tumors as the therapy of choice. However, the best approach to the posterior wall and the posterior left atrial structures remains debatable. Although cardiac autotransplantation has been repeatedly described for the treatment of cardiac tumors [3] [4], a less radical approach than complete explantation of the heart may be desirable. Recently, we published a new partial ex situ heart surgery technique aimed at reaching the posterior structures of the heart without the need for complete explantation and cardiac autotransplantation [5]. In our case, partial excision of the heart was commenced by transection of the inferior vena cava and circumferential transection of the left atrium starting close to the sulcus interatrialis, extended caudally first, then to the left up to left atrial appendage, finishing with detachment of the roof of the left atrium after the apex of the heart had been lifted. We obtained excellent exposure of the posterior left ventricle and left atrium using this technique. The procedure was performed with the heart fibrillating, and aortic cross-clamping and myocardial ischemia was avoided. Only the inferior caval vein and the left atrium had to be reconstructed; total cardiopulmonary bypass time was 85 min. The patient was extubated 6 hours postoperatively, and the postoperative course was uncomplicated. He is doing well 6 years after the operation. Indication for the operation has been an arteriovenous angioma located at the posterior left ventricular wall.

Our partial ex situ surgery technique on the heart bears several advantages in comparison to explantation and cardiac autotransplantation. First, the duration of the procedure including cardiopulmonary bypass time is much shorter; an easier postoperative course can therefore be expected. Second, cardioplegic arrest with myocardial ischemia can be avoided; the heart recovers more quickly, and postoperative extracorporeal membrane oxygenation following long cardiac arrest as reported is unlikely to occur. Third, since transection of the superior caval vein, aorta and pulmonary artery is not required, our technique potentially preserves myocardial enervation. We have also successfully applied our technique in patients with posterior-wall aneurysms after myocardial infarction, allowing excellent exposure for simultaneous inspection both of the outside and the inside of the posterior left ventricular wall. The limitation of this technique is the incomplete exposure of the posterior aortic root and pulmonary main stem compared to the explanted heart.

In conclusion, partial ex situ surgery of the heart offers an excellent alternative to complete cardiac explantation and autotransplantation. If applicable, this technique should be preferred for exposure of the posterior aspect of the heart.

References

• 1 Hoffmeier A, Scheld H H, Tjan T DT. et al . Ex situ resection of Primary Cardiac Tumors.  Thorac Cardiov Surg. 2003;  51 99-101
• 2 Scheld H H, Nestle H W, Kling D. et al . Resection of a heart tumor using autotransplantation.  Thorac Cardiovasc Surg. 1988;  36 40-43
• 3 Cooley D A, Reardon M J, Frazier O H, Angelici P. Human cardiac explantation and autotransplantation: application in a patient with a large cardiac pheochromocytoma.  Tex Heart Inst J. 1985;  12 171-176
• 4 Murphy M C, Sweeney M S, Putnam J B. et al . Surgical experience of cardiac tumors: a 25-year experience.  Ann Thorac Surg. 1990;  49 612-618
• 5 Kallenbach K, Cremer J, Haverich A. Partrial ex situ surgery of the heart.  J Thorac Cardiovasc Surg. 2002;  123 577-578