Objective: Cardiac storage solutions and methods remain unstandardized. We have surveyed the literature to establish how the subject has progressed, addressing models of preservation and measures of outcome. Since a lot of the literature on cardiac storage is generated in the laboratory, we were particularly interested to evaluate to what extent bench work finds its way into and clinical practice. The discussion focuses in addition to new areas of research and introduces the concept of integrated organ preservation.
Methods: Five representative journals (J Thorac Cardiovasc Surg, Circulation, J Heart Lung Transplant, Eur J Cardio-thorac Surg and Ann Thorac Surg) were searched by hand for papers published between 1980-1999. All laboratory, animal experimental and clinical studies focused on prolonged cardiac preservation and storage were selected.
Results: Two hundred and forty-nine publications were identified using preset criteria. Of these, 196 (79%) were studies performed in animal models and 10 (4%) were experiments carried out on animal tissue. One hundred and five experiments (42% of all studies) were performed in small animals. The most common animal model was of ischemia followed by ex vivo reperfusion (121 studies, 49% of publications). The measures of outcome were classified as biochemical, functional, morphologic and endothelial; the majority of studies had one (48%) or two (40%) end-points. Twenty-five studies (10%) had endothelial measures of outcome, alone or in combination with other types of outcomes. Human clinical work was represented by 34 (14%) studies of clinical transplantation and nine (4%) experiments on human tissue only. There were five randomized clinical trials, representing 2% of all papers and 15% of all clinical research.
Conclusion: In conclusion, most of the surgical publications on prolonged cardiac preservation result from animal research. Small animal models of ex vivo ischemia and reperfusion are predominant.