Study population
A total of 210 patients were analyzed. Mean age was 70 years and 35.2%
of the patients were female. Fourteen patients (6.7%) had a previous
stroke and 33 (15.5%) were in atrial fibrillation. Baseline
characteristics are shown in Table 1.
Surgical details are summarized in Table 1. The most common arterial
return was through the axillary artery (61.9% of the cases), followed
by direct aneurysm cannulation (23.8%), while venous drainage was
mainly atriocaval. Associated surgeries were coronary artery bypass
grafting in 21.4% of the patients and aortic valve repair/replacement
in 49.6%. Mitral and tricuspid valve repair were performed only in 4
cases (1.9%).
Fifty-nine patients (28.1%) underwent DHCA at ≤ 20°C without any CP. In
151 cases (71.9%) surgery was performed at moderate hypothermia (26°C)
and ACP was obtained through the axillary artery only in 51.7% of the
cases, direct cannulation only in 13.9% of the cases while in the
remaining 34.4% a mixture of the two methods was used. In 42 cases
(27.8%) the left subclavian artery was perfused as well. The median CA
time was 24 min, shorter when DHCA (21 min) was used and longer in case
of MHCA (26 min) without statistical significance. CA time was
>40 min in 19 patients (9%) and >50 min in 11
(5.2%), without any difference when deep or moderately hypotermic CA
was used.
Total arch replacement was performed in 103 cases (49%) and ascending
aorta with hemiarch replacement in the remaining 107 (51%). An elephant
trunk was performed in 61 patients (29%), conventional in 4 (1.9%) and
frozen in 57 (27.1%). Median CPB time was 150 min and was not affected
by the temperature of the CA. Modality of rewarming after CA were
different. In all patients who underwent DHCA rewarming was delayed for
a period of 10 minutes, with perfusate temperature at
20°C1,2. Patients undergoing MHCA were rewarmed as
soon as the perfusion restarted.