Evaluating neurological outcomes of and risk factors for hypoattenuated leaflet thickening following aortic root replacement and arch surgery

Objectives: In this retrospective study, we aimed to assess incidence, possible causes and clinical consequences of hypoattenuated leaflet thickening (HALT) following aortic root replacement with valved composite grafts and concomitant aortic arch repair.

Methods: Between January 2016 and December 2022, 454 patients underwent Bentall procedures with arch replacements in hypothermic circulatory arrest at the University Aortic Centre MunichLMU, Germany. Sequential postoperative ECG-gated, high-resolution computed tomography angiographies were analyzed, and the presence of HALT correlated with neurologic events and transvalvular gradients over time. Furthermore, attention was given to intraoperative hemostatic product use and postoperative anticoagulation regimes.

Results: 327 out of 454 patients were included. The follow-up period averaged to 3.27 years. 28% of the patients showed radiographic signs of HALT, which was correlated with a significantly higher incidence of transient neurological events as compared to those without (38 versus 8 events, p < 0.01). However, there were no significant differences with respect to the postoperative anticoagulation regimen or transvalvular gradients between the two groups. Only the intraoperative administration of prothrombin complex concentrate was significantly higher in patients with postoperative HALT.

Conclusion: HALT is observed in a high percentage of cases following aortic root replacement combined with complex aortic procedures. Furthermore, it is associated with an increased risk of neurological events but only a weak correlation was demonstrated with the perioperative coagulation management. While no long-term implications were noted, these findings suggest the necessity for further investigations, longer follow-up periods, and more comprehensive diagnostic approaches.