Purastat post-EMR: unresolved questions from the PURPLE trial

Abstract

We read with interest the recently published PURPLE trial evaluating the prophylactic use of Purastat to prevent delayed bleeding following EMR of large duodenal and colorectal lesions.1 While we acknowledge the importance of randomised trials in shaping clinical practice, several methodological concerns in this study limit the interpretability and clinical applicability of its findings. The trial was prematurely halted following an interim analysis involving only 200 patients. We believe this pragmatic interim analysis might have been conducted too early on too small a sample size, potentially underpowering the study to detect a clinically relevant effect. The initial hypothesis of an 80% reduction in delayed bleeding in the Purastat arm, based on results from a clipping study by Albéniz et al ,2 appears overtly optimistic. The power calculation was based on an anticipated 2% delayed bleeding rate in …