Peri-aortic fluid after surgery on the ascending aorta: Worrisome indicator of complications or innocent postoperative finding?

Objective: The Bentall procedure is associated with several complications often accompanied by accumulation of fluid around the aortic graft. CT is the imaging modality of choice to detect these complications. Since these early complications are, however, not easily distinguished from physiological postoperative changes, our aim was to compare the appearance and amount of peri-aortic fluid on early CT scans following Bentall procedures with either an uncomplicated or a complicated course and follow-up.

Methods: Ninety-four scans performed within 3 months of a Bentall procedure were retrospectively included. Patients were divided into either the uncomplicated or the complicated group based on occurrence of Bentall-related complications or death up until 1-year after surgery. Diffuse fluid ("stranding") was distinguished from organized, more clearly delineated fluid collections such as haematomas, and was graded both subjectively and quantitatively.

Results: Forty-seven patients were assigned to each group. Stranding was found on most of the scans, both in the uncomplicated (7.7±3.9mm, range 0-17mm) and complicated (6.9±5.5mm, range 0-19mm) groups (p=0.32). There were, however, significantly more fluid collections (6 vs. 28; p <0.001), particularly haematomas (1 vs. 17; p<0.001), in the complicated group. When looking at isolated stranding, there was still no significant difference between the two groups (7.8±3.6mm vs. 9.2±3.7mm; p=0.22).

Conclusion: Isolated stranding of up to 17mm is a common finding on postoperative CT within three months of a Bentall procedure, regardless of the occurrence of complications during the procedure or within a 1-year follow-up. Fluid collections are more worrisome indicators of complications that may require closer monitoring.