What are the main graft sites for harvesting hearts from donors?

Main Graft Sites for Heart Harvesting

The primary graft sites for heart harvesting include the superior vena cava, inferior vena cava, pulmonary veins, aorta, and pulmonary artery, which are carefully dissected during the procurement procedure to ensure optimal organ viability for transplantation. 1

Surgical Approach to Heart Procurement

Anatomical Structures and Dissection Technique

• The aorta and pulmonary artery are dissected superiorly to the level of the innominate artery and bifurcation, respectively 1
• The superior vena cava is encircled and dissected superiorly to the level of the azygous vein 1
• The inferior vena cava is divided at the diaphragm during the procurement procedure 1
• The pulmonary veins are carefully dissected and divided at the pericardial reflections 1

Surgical Sequence

• After dissection is complete, the donor is heparinized and a cardioplegic cannula is placed in the ascending aorta 1
• The superior vena cava is doubly ligated and divided as far cephalad as possible to avoid injury to the sinoatrial node 1
• The ascending and descending aortas are clamped simultaneously while cardioplegic solution is infused 1
• The right superior pulmonary vein is incised to vent the heart and prevent distension 1
• The heart is excised at the pericardial reflections in the following order: completion of the inferior vena cava incision, division of the pulmonary veins, and finally division of the aorta and pulmonary arteries 1

Preservation Techniques

Traditional Cold Storage

• After procurement, the heart is brought to a back table where it is thoroughly rinsed with saline solution 1
• The atrial septum is inspected, and if a patent foramen ovale is present, it is closed with sutures 1
• The heart is then stored in iced saline solution for transport and implantation 1
• St. Thomas solution is commonly used as it provides up to 5 hours of safe cold storage 1

Advanced Preservation Methods

• Newer technologies include the SherpaPak Cardiac Transport System for controlled hypothermic preservation and the Transmedics Organ Care System for ex vivo perfusion 2
• These technologies are expanding the geographic reach of procurement teams and enabling the use of donation after cardiac death (DCD) hearts 2
• Normothermic regional perfusion (NRP) is a novel method that allows functional assessment of DCD hearts by restoring function to the arrested heart within the donor 3

Donor Selection and Management

Donor Criteria

• Visual inspection and palpation of the heart are the final steps in determining donor suitability 1
• Palpable thrills over great vessels, obvious atherosclerotic lesions of epicardial coronary arteries, or areas of myocardial contusion should preclude transplantation 1
• ABO compatibility is the primary consideration for donor eligibility to prevent hyperacute rejection 4

Medical Management of Donors

• Maintaining hemodynamic stability is crucial after brain death has been declared 1
• Continuous monitoring of intraarterial pressure, central venous pressure, and urinary output is mandatory 1
• Fluid resuscitation should be initiated with a bolus infusion of 1,000 ml of balanced salt solution and maintained with hourly infusions 1
• Blood transfusions may be necessary to maintain hematocrit levels above 30%, particularly for multiple organ donors 1

Emerging Trends: Donation After Circulatory Death (DCD)

DCD Heart Transplantation

• DCD heart transplantation is a rapidly expanding practice that increases the donor pool 5
• There are at least three protocols that permit resuscitation and viability assessment of DCD hearts either in situ or ex situ 5
• Outcomes of DCD heart transplant recipients are excellent and comparable to those from donation after brain death (DBD) donors 5
• In centers with the largest published experience, DCD heart transplantation now accounts for one-third of heart transplant activity 5

DCD Heart Assessment

• Normothermic regional perfusion allows rapid reperfusion and functional assessment of the DCD donor heart 3
• This technique ensures only viable hearts are selected for transplantation, minimizing the risk of primary graft dysfunction 3
• Clinical outcomes show excellent results with DCD heart transplantation, with survival rates comparable to contemporary brain-dead donors 6

Common Pitfalls and Considerations

• Inadequate dissection of the great vessels can lead to technical difficulties during implantation 1
• Injury to the sinoatrial node during superior vena cava division can cause post-transplant arrhythmias 1
• Prolonged warm ischemia time significantly impacts graft viability, particularly in DCD donors 5
• Proper donor management is essential, including treatment of diabetes insipidus with vasopressin and maintenance of electrolyte balance 1