Organ/head perfusion devices

Normothermic organ perfusion (NOP) represents a transformative approach to organ preservation, enabling organs to remain viable and functional outside the body for unprecedented durations. Unlike traditional cold storage methods, these systems recreate physiologic conditions by maintaining body-like temperatures, oxygenation, and nutrient delivery. This technique can significantly prolong preservation times, improve organ quality, and ultimately increase the number of suitable organs available for transplantation. NOP may increase organ utilization rates, which is crucial given that certain categories of donor organs remain unused in most cases.

For the heart, NOP has extended the preservation window well beyond standard time limits. Conventionally, hearts become unsuitable for transplantation after approximately 4–6 hours in cold storage. However, normothermic machine perfusion has maintained functional human hearts for up to 24 hours, demonstrating stable myocardial contractility and reduced biochemical injury markers (B. Spencer, 2024). 

Liver preservation research illustrates even more prolonged viability. Isolated human livers have been maintained for over 12 days in a normothermic environment, retaining metabolic function, bile production, and histological integrity (NS. Lau, 2022). Furthermore, integrating extracorporeal blood purification techniques has enabled perfusion of a tumoral human liver for 17 days, underscoring the adaptability of these systems (U. Cillo, 2024). 

Kidneys have been sustained for extended durations using perfusion techniques. In a study, porcine kidneys were maintained ex vivo for up to seven days with various perfusates, including human and animal blood-derived solutions, while retaining viability and functionality (Tietjen GT et al., 2020). Another investigation demonstrated that discarded human kidneys could be preserved for up to 48 hours, showing significant reductions in delayed graft function and improved graft survival when compared to static cold storage (Peters-Sengers H et al., 2021). Additionally, it was shown that both autologous and allogeneic red blood cells were suitable for maintaining functional parameters during perfusion, further supporting the feasibility of kidney preservation for extended durations (Nicholson ML et al., 2022).

Other organs, lungs, intestine, pancreas and limbs, have also been perfused ex vivo to varying degrees of success. Extending these techniques to the central nervous system has proven challenging but feasible. Pig brains have been maintained ex vivo with extracorporeal pulsatile circulation, preserving some functional and metabolic markers (M. Shariff, 2023). Post-mortem pig brains have shown restoration of circulation and cellular functions hours after death, demonstrating the potential to mitigate early ischemic damage (Z. Vrselja, 2019). This work was later extended to whole body (D. Andrijevic, 2022). Historical studies have maintained isolated non-human primate and rodent brains with artificial perfusates (R. J. White, 1963; M. Muhlethaler, 1993), and the presence of a perfused liver in the circuit has been shown to preserve neuronal viability and electrocortical activity in models of global ischemia (Z. Guo, 2024).

Building on this work, the development of a perfusion platform specifically for the head would apply these established principles to a highly complex organ system. By refining circulatory control, metabolic support, and waste clearance to meet the head’s unique demands, it may become possible to sustain integrative brain activity ex vivo. Such progress has implications for improving transplantation protocols, extending viable preservation times, and advancing research on neuroprotection, neuromodulation, and ultimately, new interfaces between biological and engineered systems. Importantly, keeping a disembodied head in homeostasis would mark the first tangible step toward becoming a cyborg.