Extracorporeal support: improves donor renal graft function after cardiac death

Area of Science:

• Transplantation immunology
• Organ preservation
• Nephrology

Background:

• Donors after cardiac death (DCD) offer a potential solution to expand the deceased donor organ pool.
• However, delayed graft function and primary nonfunction in DCD kidneys limit their utilization.
• Extracorporeal support after cardiac death (ECS-DCD) has emerged as a strategy to mitigate these complications.

Purpose of the Study:

• To evaluate the immediate and acute renal function of kidneys from different donor types.
• To compare the efficacy of conventional rapid recovery versus ECS in DCD kidney recovery.
• To assess the impact of varying warm ischemia times on DCD kidney function post-transplantation.

Main Methods:

• Kidneys from DCD donors (recovered conventionally or with ECS) and living donors (LVD) were transplanted into nephrectomized swine.
• Warm ischemia times of 10 and 30 minutes were investigated for DCD kidneys.
• ECS-DCD kidneys underwent 90 minutes of perfusion prior to cold storage (4-6 hours) and transplantation.
• Post-transplant assessments included renal vascular resistance (RVR), urine output (UO), urine protein concentration (UrPr), and creatinine clearance (CrCl) over 4 hours.

Main Results:

• All transplanted kidney grafts demonstrated adequate renal blood flow during the 4-hour assessment period.
• Renal vascular resistance (RVR) returned to baseline levels only in the LVD group, remaining elevated in all DCD groups.
• While urine output exceeded 50 mL/h in most DCD groups, the DCD group with 30 minutes of warm ischemia (DCD-30) exhibited significantly reduced urine output (6.8 mL/h).
• The DCD-30 group also showed lower creatinine clearance (0.9 mL/min) and higher urine protein concentration (>200 mg/dL) compared to other DCD groups.

Conclusions:

• Normothermic extracorporeal support (ECS) can effectively resuscitate kidneys, rendering them transplantable even after 30 minutes of cardiac arrest and warm ischemia.
• ECS-DCD shows promise in improving the viability and function of DCD kidneys, potentially increasing their utilization in transplantation.
• The duration of warm ischemia remains a critical factor influencing post-transplant renal function in DCD kidneys, even with ECS intervention.