Heterotopic Heart Transplants

Two hearts, one body, and another chance at life. In the world of medicine, there are few images that are as powerful as the human heart – a symbol of life. Beating inside the body to a rhythm of its own pace. But imagine living not just with one, but rather two hearts inside your chest. Heterotopic Heart Transplantation (HHT), a rare surgical procedure that places a donor heart beside the original, creating a duet of survival. 

In 1974, Dr. Christiaan Barnard, who was already previously famous for performing the world’s first human heart transplant, was faced with a rather difficult predicament. The patient’s heart was not fully at such a condition that could warrant a full transplantation, yet it was not as strong as to ensure their survival, asking the question: What if the heart can still fight? So, to solve this quandary, with the help of Dr. Losman, he pioneered the heterotopic transplant, which involved keeping the failing heart, and thus connecting the two in circulation (Copeland, J. & Copeland, H., 2016). 

Now, the question stands: Why two hearts? This unusual approach is usually reserved for special cases, such as for patients with severe pulmonary hypertension. This disease usually involves high blood pressure in the lungs that overwhelms a singular heart, which makes it likely that they would benefit from having two hearts (Letsou et al., 2020). Another situation where this procedure may be applied is when the donor heart is too small to support the body, so instead of fully removing the native heart, they attach the donor heart to support it. 

There are many unique aspects of Heterotopic Heart Transplantation (HHT), one of which is that the compromised native heart  remains in a certain place for a prolonged period of time, with the donor heart acting as a biological left ventricle assist device (Letsou et al., 2020). This procedure also subtly promises a better native heart after prolonged periods of heterotopic cardiac support, which allows for an almost fully recovered heart (Letsou et al., 2020).

HHT was proposed for a number of reasons which include: an increase in the size of the donor pool and decrease the waiting times for these hearts and overcoming pulmonary hypertension, while also avoiding the risk of morbidity caused by the procedure. However, only few reports have been made on the short or long term effects of this procedure, which is the reason as to why it is not the most recommended procedure to be done. 

However, with more developments in this particular procedure, combining the need to support a patient’s heart while considering the long-term impacts, it is evident that a similar, yet profoundly better procedure can be developed. But for now, in the quiet rhythms of a patient’s heart, a better, more healthy life awaits.

Written by Sophia Perez at Incisionary

References:

Copeland, J., Copeland H. (2016). Heterotopic heart transplantation: technical considerations. 

Operative Techniques in Thoracic and Cardiovascular Surgery, 21(3), 269-280. https://doi.org/10.1053/j.optechstcvs.2017.05.004 

Letsou, G. V., Musfee, F. I., Cheema, F. H., Lee, A. D., Loor, G., Morgan, J., Rosengart, T., 

Frazier, O. H. (2020). Heterotopic cardiac transplantation: long term results and fate of the native heart. The Annals of Thoracic Surgery, 110(4), 1316-1323. https://doi.org/10.1016/j.athoracsur.2020.02.018

Flécher E., Fouquet O., Ruggieri V. G., Chabanne C., Lelong B., Leguerrier A. (2013). 

Heterotopic heart transplantation: where do we stand? Eur J Cardiothorac Surg, 44(2):201-6. https://doi.org/10.1093/ejcts/ezt136