Page 210 - Read Online

Page 6 of 9 Pragliola et al. Vessel Plus 2019;3:22 I http://dx.doi.org/10.20517/2574-1209.2019.003

In many institutions, including ours, the del Nido was initially used in minimally invasive Mitral cases and
then gradually extended to cover all procedures. This path, though not openly stated, was probably started
at the Columbia University and followed in Cleaveland where the Del Nido was propensity matched with
[21]
good results to the Buckberg solution in minimally invasive or robotic valvular cases and showed better
glucose control, reduced cross-clamp and operative times.

As the field of minimally invasive and robotic surgery is rapidly expanding, teams dealing with these
techniques are looking for a simple and effective cardioplegia. Amongst the available alternative solutions,
the Buckeberg entails a staged deliver in different phases and shorter intervals of ischemia (15 m to 20 m)
[19]
which can slow down the surgical workflow. Besides, the retrograde infusion in minimally invasive surgery
is a sophisticated and sometime difficult technique to control in a limited surgical field. The Custodiol® [22]
solution for long time has been the only single shot cardioplegia. Initially introduced for the donor hearts that
usually are exposed to long ischemic times during organ procurements, it achieves a long-lasting myocardial
protection. However, this solution requires the infusion of a large volume of hyponatremic crystalloid
which is usually drained during the donor heart harvest but can be problematic in patients operated with a
minimally invasive approach. Although ultrafiltration can help solve this problem, the volume overload and
the hyponatremia can complicate the postoperative period.

There are also several studies testing the DNC in coronary revascularization. Timek et al. reported on a
[23]
group of CABG patients receiving the DNC, propensity score matched to a population operated with usual
Cold Blood Cardioplegia infused at 15-20 min intervals. Not surprisingly the DNC resulted in a lower volume
infused and a lower peak glucose level during cardiopulmonary bypass compared to the matched population.
No clinical differences were noted in the outcomes.

The DNC has also been tested in high risk coronary cases with Acute Myocardial infarction by Yerebakan et al.
[24]
in 2014 with excellent clinical results. Two recently published Randomized Controlled Trials (RCT) compared the
use of the DNC to the intermittent whole blood cardioplegia in CABG or CABG plus valve surgery. Ucak et al.
[25]
could observe shorter aortic cross-clamp and CPBP times and better glucose control in the DNC group, without
meaningful clinical differences in a population with an average Euroscore of 4.1. Similarly, Ad et al. conducted
[26]
the single registered RCT (NCT02442050) for the DNC in adults. The randomized patients had an average STS
score of 1.3. Initially designed as a non-inferiority study to include 500 patients, it was prematurely interrupted
because the DNC patients had a better rhythm recovery after surgery. The study was then turned into a superiority
study with a required level of evidence of P < 0.001. With these new parameters there were no clinical differences in
the outcome although the peak T troponin level was lesser in the DNC group at P < 0.04 without sufficient power
to achieve statistical differences. Table 1 summarizes the available studies. Many of them where also included in an
extensive metanalysis which favoured the del Nido in reducing the volume of cardioplegia infused, shortening the
cardio-pulmonary bypass and cross clamp times and hade comparable results in terms of troponine and CKmb
release. All the studies had comparable clinical results [27,32] .

In the available literature, the common criticisms to the use of the DNC in adults are two: the limited
number of patients included in the studies, usually with a single pathology and the low risk of these groups
of patients.

In his elegant statistical study, Kim et al. matched two similar groups of 104 patients treated with the
[21]
DNC or Blood Cardioplegia out of 1041 consecutive patients. Again the DNC showed an advantage in the
postoperative peak troponin release and shorter cross-clamp times. Noticeably all kind of procedures were
done in these groups, including multiple complex valves and aortic arch surgery. However, the logistic
Euroscore II for the DNC group was 2.9 ± 3.3.