Lifelike revascularization of embalmed kidneys: a promising new surgical training model?

Introduction: Patient safety and limited working hours for surgical trainees necessitate a growing use of surgical training tools, of which human bodies are the most realistic. Currently, a revascularized human training model mimicking reality, however, has been lacking. Objectives: To install a lifelike prolonged circulation in embalmed kidneys. Material/Patients and methods: The renal artery and vein of 13 goat kidneys and 8 pig kidneys were cannulated. Thiel embalming fluid was injected via the artery. Seven kidneys were additionally immersed in a Thiel embalming bath. To lose weight, 19 kidneys were afterwards brined. Then, again, both vessels were cannulated and connected to a roller pump, which installed a circulation using liquid paraffin or polyethylene glycol. Reperfusion time, flow rate and weight were measured. Results: Embalming resulted in a substantial weight gain (mean: 31.4%). Brining efficiently dehydrated the kidneys (mean weight loss: 13.3%) and was most successful if no embalming bath was used. Pump driven circulation was installed in every specimen at flow rates of 15-30 cc per minute during 15-120 minutes. Polyethylene glycol mixed with water enabled the longest reperfusion with least weight gain and acceptable preservation of pliability. Conclusions: Sole use of Thiel perfusion fluid adequately embalms kidneys and subsequent brining efficiently diminishes swelling enabling recovery of original weight. Pump-driven reperfusion based on polyethylene glycol was installed during longtime without obvious change of the constitution of the kidneys. This realistic model has promising properties, however, further elaboration is needed to eventually develop the most realistic surgical training tool ever