Lung ultrasound as a monitoring tool in lung transplantation in rodents: a feasibility study

Background: Orthotopic lung transplantation in rats has been developed as a model to study organ dysfunction, but available tools for monitoring the graft function are limited. In this study, lung ultrasound (LUS) is proposed as a new non-invasive monitoring tool in awake rodents.Methods: LUS was applied to native and graft lung of six rats after left orthotopic transplantation. Rats were monitored with LUS while awake, patterns identified, images evaluated with a scoring system, intra-and inter-rater agreement was assessed and examination times analyzed.Results: A total of 78 clips were recorded. The median quality score of LUS was 3.66/4 for left hemithorax and 3.71/4 for native right side. The intra-rater agreement was 0.53 and 0.65 and the inter-rater agreement was 0.61 (P<0.01). Median time to complete the examination was 233.0 seconds (IQR 142) for both lungs, lowered from 254.0 seconds (IQR 129.5) (first trimester of study) to 205.5 seconds (IQR 88.5) (second trimester of the study). Significant findings on LUS were confirmed on pathological examination.Conclusions: LUS in awake rodents without shaving has been shown to be both feasible and safe and the images collected were of good quality and comparable to those obtained in anesthetized rats without bristles.