**2.1 DBD: heart only procurement**

First, we will focus on an isolated heart procurement. This is with the understanding that it is the sole organ being procured from the chest.

The surgeons must first familiarize themselves with the donor's vital signs, ECG, ECHO, angiogram, labs and any other form of imaging that's available in order to assess the hemodynamic stability and anatomy of the donor to avoid surprises. Perhaps even more importantly, donor blood type and match information must be confirmed. These are (but not limited to) the donor's MHC status, antibody checks, and ABO

blood type compatibility. Other donor information such as Hepatitis B, Hepatitis C, and HIV status should also be double checked in the donor chart on site. Discrepancies should be conveyed to the rest of the transplant team at the recipient site immediately. The suitability of the organ with respect to size match in terms of a predicted heart mass ratio should be confirmed. At the site, a copy of the consent for donation and the donor's brain death status as per the specific state's legislated criteria are to be obtained for the procurement surgery teams records. Finally, confirm that the donor had no other changes in status since the procurement team's original debrief and arrival at the site. Specifically, the surgeon must look out for worsening lab values, such as changes in the lactate levels, and any increase in pressor requirements. The usage of Thyroxine (T4) as part of the donor recruitment process is also recommended [2].

The procurement team's next step should be to assess if there is appropriate arterial and venous access for the donor. At times one sees that the donor only has a femoral arterial access line. This leaves the patient without any blood pressure monitoring when the abdominal team ligates the aorta during their cannulation. Because of this, the anesthesia team can get alarmed and give boluses of pressor medications, which in turn can have a deleterious effect on the heart. Therefore, we recommend upper limb invasive pressure monitoring system such as a radial artery line or brachial arterial access.

The sternum is opened via a median sternotomy in a standard fashion limiting blood loss and securing hemostasis. It is our practice to measure intracardiac pressures from the Right Atrium, Left Atrium and Pulmonary Arteries from the donor heart to get an accurate estimate of the patient's hemodynamics. These parameters are immediately communicated to the implanting surgeon. These measures give the team a snapshot of the cardiac function of the donor's heart.

The heart surgeon will have to share the IVC with the liver surgeon. This can be a point of contention regarding the length of IVC to be taken by the cardiac surgeon versus the length taken by the liver transplant team. An ambitious cardiac surgeon might divide the IVC at the level of the diaphragm with traction on the heart to the extent where the IVC retracts below the diaphragm and leaves but a stump for the liver transplant team. Hence, it is prudent to discuss with the liver surgeon beforehand as to where to transect the IVC. Staying above the diaphragmatic reflection has been the standard practice. Avoiding traction while harvesting is important, though one often sees the liver team retracting the liver down!

The procurement surgeon should pay special attention to the venting that is done to decompress the donor heart. With multiple teams sitting in the fray, this aspect of the surgery is often ignored at the patient's peril. The techniques to vent the heart are either through the LA appendage, the interatrial groove, the posterior left atrial wall or directly amputating the pulmonary veins [3]. In this scenario, where we are discussing heart only procurement, it is useful to vent through the pulmonary veins (the pulmonary vein orifices can be connected in the back table). However, if other thoracic transplant teams (like the lung team) are involved then they will be perfusing the lungs with 4–6 liters of Perfadex *(PERFADEX® Plus is an extracellular, low potassium, dextran-based electrolyte preservation solution for rapid cooling, perfusion and cold static storage of donor lungs – pre-supplemented with calcium ions and THAM*; Perfadex® Goteborg, Sweden solution). Our experience shows that it is best to vent through the left atrial appendage. Venting through the interatrial groove can also be done (must be dissected out before the cross-clamp application) but it comes with a major hazard- the heart may go into atrial fibrillation and cause hemodynamic compromise. Venting primarily through the posterior left atrial wall is also an option.

For this, the surgeon first picks up the heart to access that portion of the left atrium but once the opening is made and the heart is let down back into its position in the chest cavity, it is not predictable if the hole will stay open to adequately vent the heart. Furthermore, lifting the heart during cardioplegia administration might

cause aortic sufficiency. The pulmonary veins can be amputated at their origins and we can divide the pulmonary artery as high as we need to in order retain the bifurcation. It is also wise to divide the SVC high up above the azygos vein to give the implanting surgeon additional SVC length.

These are special situations in which it is important to know the anatomy of the recipient and to discuss with the implanting surgeon specific requirements.
