Clamp On vs Off Impact of Distal Anastomotic Technique During Ascending Aortic Replacement in Acute Type A Aortic Dissection: IRAD Insights

OBJECTIVES: Most ascending aortic replacements for acute type A aortic dissection (ATAAD) are performed utilizing hypothermic circulatory arrest with an "open" distal anastomosis ("hemiarch"), whereas some are completed without ever removing the aortic cross-clamp. We sought to determine the impact of distal anastomotic technique in ascending aortic replacement for ATAAD repair. METHODS: All patients in the IRAD Interventional Cohort database who underwent ATAAD repair between 2010 and 2020 were identified (n = 2559). Data for distal anastomotic technique were available in 2031 patients who underwent ascending aortic replacement, divided into 2 groups, based on whether they underwent hypothermic circulatory arrest (Clamp Off, n = 1900 [93.5%]) or not (Clamp On, n = 131, [6.5%]). We then propensity-matched 101 pairs of patients and analysed operative data and short- and mid-term outcomes. RESULTS: In-hospital mortality for the unmatched population was 13.1% (266 deaths), not statistically different between the matched groups (Clamp Off, 11.0% vs Clamp On, 5.1% P = .22). There were no statistically significant differences observed in 3-year post-discharge survival curves between matched cohorts (Clamp Off, 89.5% vs Clamp On, 90.4%; stratified log-rank P-value = .46). Major perioperative complications (renal failure requiring dialysis, reoperation for bleeding, respiratory insufficiency) were not significantly different between the groups, notably including stroke (Clamp Off, 10.2% vs Clamp On, 5.8%, P = .32). CONCLUSIONS: In this propensity-matched cohort, postoperative mortality, major morbidity, and mid-term survival were comparable between open distal anastomosis and clamp-on strategies in selected patients undergoing ascending aortic replacement for ATAAD.