Comparison of short-term outcomes of mild and moderate hypothermic circulatory arrest in aortic arch surgery: a single center retrospective cohort study.

BACKGROUND

Aortic arch surgery is one of the major challenges in modern aortic surgery, special cerebral and visceral organ protective strategies are still under progress. Whether mild hypothermic circulatory arrest (Mi-HCA) can be safely used in aortic arch surgery (AAS) is the focus of attention.

METHODS

From January 2017 to June 2021, a retrospective cohort study of 138 consecutive patients was conducted at Beijing Anzhen Hospital. The study comprised patients who underwent AAS performed by a single surgeon during moderate-to-mild HCA. According to the core temperature at the beginning of circulatory arrest, the patients were divided into three groups: T group (n=45; 25.76±0.75 ℃), T group (n=43; 28.79±0.81 ℃), T group (n=50; 31.46±0.79 ℃). Perioperative clinical data were analyzed to assess the differences between groups.

RESULTS

In this cohort, the average durations of the operation, cardiopulmonary bypass (CPB), cross-clamp, circulatory arrest, and selective antegrade cerebral perfusion (SACP) were 6.53±1.48 h, 184.07±56.69 min, 101.04±37.92 min, 23.01±9.86 min, and 27.18±11.52 min, respectively. We observed new postoperative permanent neurological dysfunction (PND) in 12 patients (8.7%) and transient neurological dysfunction in 18 patients (13.04%). The in-hospital mortality rate was 6.52% (n=9). The durations of the operation, CPB, cross-clamp, circulatory arrest, and SACP were significantly reduced in the Mi-HCA group (i.e., T group, P<0.001; P<0.001; P<0.001; P=0.002; P<0.001, respectively). The incidence of PND and major adverse events (MAEs) were significantly reduced among the three groups (P=0.025; P=0.035). Multivariate logistic regression analysis models showed that Mi-HCA was an independent protective factor in reducing postoperative MAEs [relative risk (RR) =0.12; 95% confidence interval (CI): 0.02-0.90; P=0.0385].

CONCLUSIONS

The short-term outcomes of Mi-HCA combined with SACP in AAS were acceptable. Similarly, the protection of distal organs and the spinal cord was observed compared to the MHCA strategy, and a lower incidence of MAEs was obtained. Current data suggest that the mild hypothermia strategy can be safely applied for AAS.