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DCD Organ Procurement with Normothermic Regional Perfusion

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posted on 03.05.2022, 15:53 authored by John M. Trahanas, Jordan R. Hoffman, William G. McMaster, Yulia Tipograf, Tarek S Absi, Keki R. Balsara, Ashish S. Shah

  

This video demonstrates the authors’ technique for the recovery of organs from donation after circulatory death (DCD) donors using normothermic regional perfusion (NRP). 

Withdrawal of Care 

To start, heparin is given to the donor before withdrawal of care. The donor is then extubated. Ideally, the donor is prepped and draped prior to extubation, though this can be done during the standoff period. Up to thirty minutes of agonal phase can be tolerated, defined as sustained blood pressure less than systolic 50. No need to pay mind to the saturation. 

Once the patient has been declared dead, there is an obligatory standoff period that typically ranges between two and five minutes depending on the recovery center. After the stand off period a second confirmation of death is performed and at that point incision is made. The donor’s arch vessels are clamped to exclude cerebral perfusion, and the donor is cannulated. The typical period from incision to establishing extracorporeal flow is three to five minutes. Perfusion is continued for forty-five minutes, after which the organs are harvested in the usual manner. 

Before extubation, it is important to have a Mayo stand prepared with the necessary instruments and cannulas so that the surgical team can self-serve.The pump also needs to be set up in advance. The authors use a modified cardiopulmonary bypass circuit that includes a reservoir and a cardiotomy suction line. 

Organ Procurement 

After the second declaration of death, an incision is made over the sternum. It is important to take a few extra seconds to ensure that the sternotomy will be midline, as being off midline creates quite a difficult exposure and complicates the procedure. 

The sternum is then opened using a standard sternal saw, and a retractor is placed. While the assistant opens the retractor, the surgeon exposes the pericardium and opens the pericardium, taking care not to injure the heart. 

The pericardium is opened widely and carried cranially up to the level of the innominate artery. The assistant then retracts down on the heart with their left and retracts the innominate vein cranially to provide exposure the innominate artery. Next, the surgeon bluntly dissects the pericardial reflection over and under the innominate artery and, using some brutee force, slides a vascular clamp across all three head vessels to exclude the cerebral circulation from the pump flow. 

A small C-clamp is then placed on the right atrial appendage to stabilize it and prevent it from becoming submerged in blood once the atriotomy is made. The atrium is incised with an 11 blade, and a dual stage venous cannula is positioned in the usual manner. The cannula is then connected to the drainage line of the pump, and patient is then drained to the pump to relieve the venous distention. The assistant then holds the venous line with their left hand. 

After this, the aorta is grasped by both the surgeon and assistant with forceps, and a 5mm incision is made on the anterior aspect of the aorta. A Soft-Flow cardioplegia cannula is then inserted into the aorta much deeper than would be done during a normal cannulation. In the video above, you can see that the bumper on the cannula has been moved back to the 5cm mark. The assistant then uses their right hand to hold the aortic cannula. The assistant does not move until both cannulas are secure. 

The surgeon then connects the cannula and uses a syringe attached to a three-way stopcock to de-air the line. Once the line is fully de-aired, the stopcock is closed and bypass is initiated. If blood has filled the field, the drop sucker attached to the cardiotomy line can be placed in the field to salvage the blood and allow visualization of the aorta. Once stable bypass flow has been established, a purse-string suture is placed around the aortic cannula and secured with a Rummel tourniquet and a silk tie. This serves not only to provide hemostasis but also to secure the cannula. The same is done to the right atrium and the venous cannula. 

Once the cannulas have been secured, the next step is to place a cardioplegia needle in the aorta in the usual position, which initially will serve to transduce the aortic pressure and allow the perfusionists to titrate the pump flow. As the time of cross-clamp nears, this will be switched to allow for preservation solution administration. A pulmonary artery vent is also placed to further decompress the right ventricle, as the patient is not reintubated. Oftentimes an aortic hematoma will be present, and a dissection needs to be ruled out on the back table prior to an incision on the recipient. 

At forty minutes, the donor istransiently weaned off bypass, and thethe venous line is disconnected to allow all the circuit volume to be reinfused to the donor. The appearance of the heart and the hemodynamics are assessed at that time. After about one minute, bypass is reestablished. 

At this point, once all teams have cannulated and are ready, the aorta is cross-clamped, and the heart and additional organs are preserved and explanted in the usual fashion. The heart is then packed in ice for transportation to the implant center. 

Conclusion 

The time between incision and cardiopulmonary bypass in this video accompanying this article is two minutes and forty seconds. In general, once bypass is established using NRP, the remainder of the procurement proceeds in a manner that is very similar to a brain-dead donor procurement. 

It is worth noting than NRP is a team effort between the surgeons, perfusionists, preservationists and coordinators, and all the teams deserve recognition and appreciation.


  

Reference


Hoffman, J. R., McMaster, W. G., Rali, A. S., Rahaman, Z., Balsara, K., Absi, T., ... & Shah, A. S. (2021). Early US experience with cardiac donation after circulatory death (DCD) using normothermic regional perfusion. The Journal of Heart and Lung Transplantation, 40(11), 1408-1418.

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