Deep Hypothermic Circulatory Arrest With Retrograde Cerebral Perfusion: How Long Is Safe?

Background Cerebral protection strategies during proximal aortic repair remains controversial due to lack of evidence and large patient cohort studies. We herein evaluated our 3-decade experience using hypothermic circulatory arrest with retrograde cerebral perfusion (DHCA/RCP) to evaluate for its safety and safe duration during proximal aortic repair. Methods All proximal aortic repairs using DHCA/RCP from January 1991 to December 2020 performed at our institution were included in the analyses. Perioperative variables were evaluated for mortality and cerebrovascular accident (CVA; combined stroke and transient ischemic attack). Results In all, 1429 repairs were performed using DHCA/RCP. Of these, 464 (32%) were acute aortic dissection and 297 (21%) were resternotomy. The median age was 61 years (interquartile range 50-70 years). Operative mortality was 8.9% and CVA occurred in 8.4% (stroke 7.8%, transient ischemic attack 0.6%). There was a linear relationship between the RCP time and the incidence of immediate postoperative CVA. Incidence of CVA was less than 5% when RCP time was less than 20 minutes, 6.3% at 30 minutes, and 11.5% at 60 minutes. Multivariable analysis demonstrated acute type A aortic dissection (odds ratio 2.58, 95% CI1.49-4.48, P = .001) was the only predictor for postoperative CVA but RCP time was not (odds ratio 0.991, 95% CI 0.962-1.02, P = .527). Conclusions DHCA/RCA provided satisfactory outcomes after proximal aortic operations. The safe duration of RCP with DHCA was up to 30 minutes in our experience. When the circulatory arrest time is expected to exceed 60 minutes, other adjuncts for cerebral protection should be recommended.