Applicability and reproducibility of the CPAT-grading system for pancreas allograft thrombosis.

PURPOSE

Although pancreas allograft thrombosis (PAT) incidence has progressively decreased, it remains the most common cause of early graft failure. Currently, there is no consensus on documentation of PAT, which has resulted in a great variability in reporting. The Cambridge Pancreas Allograft Thrombosis (CPAT) grading system has recently been developed for classification of PAT. In this study we aimed to assess the applicability and validate the reproducibility of the CPAT grading system.

METHODS

This study is a retrospective cohort study. Selected for this study were all 177 pancreas transplantations performed at our center between January 1 st, 2008 and September 1 st, 2018 were included.

RESULTS

A total of 318 Computed Tomography (CT) images was reevaluated according the CPAT system by two local radiologists. Inter-rater agreement expressed in Cohen's kappa was 0.403 for arterial and 0.537 for venous thrombosis. Inter-rater agreement, expressed in the Fleiss' kappa, within clinically relevant thrombosis categories was 0.626 for Grade 2 and 0.781 for Grade 3 venous thrombosis.

CONCLUSIONS

Although not perfect, we believe that implementation of the CPAT system would improve current documentation on PAT. However, it is questionable whether identification of a small Grade 1 thrombosis would be relevant in clinical practice. Furthermore, a good quality CT scan, including adequate phasing, is essential to accurately identify potential thrombus and extend after pancreas transplantation.