Aortic arch surgery with a mild-to-moderate circulatory arrest: the significance of aortic arch pathology

We read with great interest the article by Urbanski et al. [1] about aortic arch surgery using a mild-to-moderate hypothermic circulatory arrest. They evaluated a large series of patients who underwent aortic arch surgery in an elective setting. The mean temperature at circulatory arrest was 29.9°C and the mean duration of circulatory arrest was only 18 min. Surgical results were remarkable. Thirty-day mortality was only 0.9%, permanent neurological deficits and temporary neurological deficits were both also 0.9%, respectively, and there was no paraplegia. They showed quite a low incidence of postoperative acute renal failure and respiratory failure. In this series, an acute aortic dissection was excluded and most of the patients’ indication for surgery was degenerative or atherosclerotic disease. Interestingly, 299 (86%) patients had aortic valve disease and 312 (90%) patients underwent concomitant aortic valve surgery, although the reports of other large series showed that only 8% of patients had an aortic root replacement and 3.8% of patients had an aortic valve replacement [2]. Probably, in these authors’ report, many patients had aortic valve stenosis and/or regurgitation with an ascending aortic aneurysm. For this pathology, it is often an aneurysm which extends to the proximal aortic arch; therefore, sometimes a proximal arch replacement is required in addition to aortic valve or root surgery. In this setting, open distal anastomosis is an appropriate procedure to repair the proximal aortic arch. However, compared to a distal aortic arch aneurysm, the atherosclerotic change in the anastomosis site would be mild and the anastomsis technique would not be as complex and time-consuming. For repairing the distal aortic arch aneurysm, the distal anastomosis site could be deep inside the chest cavity and the aortic arch usually has significant atherosclerotic changes. Therefore, selective cerebral perfusion time and circulatory arrest time could be longer than the proximal arch repair and the risk of permanent neurological deficit could be higher. We believe that it is difficult to generalize the authors’ technique and strategy to all kinds of patient pathologies, because patient characteristics are extraordinary in this report.