Do not leave the heart arrested. Non-cardioplegic continuous myocardial perfusion during complex aortic arch repair improves cardiac outcome

Abstract

Objectives: Myocardial protection with cardioplegia alone may be inadequate during complex aortic arch surgery, potentially resulting in postoperative myocardial insufficiency. We hypothesized that non-cardioplegic continuous myocardial perfusion (CMP) is feasible and safe to protect the heart while operating on the aortic arch, and improves cardiac outcome.

Methods: Between April 2010 and April 2014, 144 patients (60% male, age: 60 ± 13 years) underwent complex aortic arch repair in our institution using prefabricated, branched aortic arch grafts. In 36 patients, the hearts were protected with a combination of cardioplegic cardiac arrest during cardiac procedures and subsequent non-cardioplegic CMP group during aortic arch repair. In 108 patients, myocardial protection was achieved by cardioplegic arrest (CA group) only.

Results: Preoperative risk factors were comparable in both groups. Acute aortic dissection was the indication for surgery in 42% (CMP) and 44% (CA) of patients; 22% (CMP) and 29% (CA) of patients underwent reoperations. Concomitant cardiac procedures were similar. CMP patients received a frozen elephant trunk more frequently (89 vs 66%, P = 0.0096). Cardiopulmonary bypass time (242 ± 50 vs 264 ± 68 min; P = 0.046), and cardiac ischaemic time (49 ± 32 vs 149 ± 56 min, P < 0.0001) were significantly lower in the CMP group. There were no conversions to CA in the CMP group. Aortic arch repair was not prolonged by CMP. Low cardiac output syndrome occurred less frequently in the CMP group (3 vs 22%, P = 0.0052). Thirty-day mortality was significantly lower in the CMP group (6 vs 21%, P = 0.040). There were no cardiac deaths in the CMP group (0 vs 9%, P = 0.067). Neurological outcome was comparable. Blood loss was higher in the CA group (P < 0.001).

Conclusions: Routinely protecting the heart during complex aortic arch repair with non-cardioplegic CMP is a valuable new concept. The CMP technique is feasible and safe, does not prolong aortic arch repair, reduces myocardial damage and improves cardiac outcome. Further evaluation in a larger patient cohort is warranted to establish this novel technique.

Keywords: Aortic arch surgery; Beating heart; Cardiopulmonary bypass; Myocardial protection.