Use of Two Novel Dyes to Enhance Visualization of Cut Ends of the Vessel in Microvascular Anastomosis–An Experimental Study of 45 Rats

Abstract

BackgroundGood visualization is a prerequisite for doing microvascular-anastomosis. The most commonly used dye-methylene-blue has several limitations: it gets washed-off-quickly and stains all the vessel-layers. The objective of our study is to use two new-novel dyes for improving visualization. MethodsAfter ethical-committee-approval, two Dyes (2% Cresyl Violet, 1% Eosin) were studied in 3 groups, 20 rats in each-group and 5 rats in the combined-group. End-to-side anastomosis was performed in classical fashion in 45 rats. After venotomy, the dye was applied to the raw-surface of the vessels subsequently anastomosis was performed. The improvement in visualisation was judged by 3 blinded experts and non-experts in four groups on a scale-of 1 to 10, scores were statistically analysed. After two-weeks, animals were re-explored to check the delayed patency, and segments were harvested for histopathological analysis. ResultsImmediate and delayed-patency-rate were-100%(45/45) and 97%(33/34) respectively. In statistical-analysis, the combined-group(p=0.005)was judged statistically significant due to the contrast-in-colour. All the layers were stained by both-dyes, staining-lasted till the end of the surgery. Visibility of the cut-ends was much better in Cresyl violet. All histopathological findings suggested normal changes at the anastomotic site. ConclusionsThis study showed that the usage of these two-dyes was not only feasible but highly efficacious. Even though all the layers were stained by both-the-dyes, the visibility of the cut-ends was much better. In both-dyes, Staining lasted till the end-of-surgery. To the best of our knowledge, this is the first-study that has used these two-novel-dyes to improve visualization in microvascular-anastomosis in an experimental setting.