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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 5, September/October 2019
AFRICA
277
Based on the present study and our clinical experience,
coronary lesions of dialysis-dependent patients are mostly
characterised by extensive, long, diffuse disease with
calcification.
10
Peri-operative mortality rate may be increased
in patients with diffuse arterial disease. Also, long-term survival
may be decreased with the OPCAB procedure due to incomplete
revascularisation in these patients.
According to our clinical observation, dialysis-dependent
patients may present with two different patterns of coronary
artery disease. Some present with typical proximal obstructions
and relatively good distal vessels. However a second group
presents with severe distal disease in addition to proximal
obstruction. The second group has increased surgical risk and
decreased chance of benefiting from the operation. In most
cases, receiving medical therapy or angioplasty may produce
better results in these patients.
Contemporary treatment models for renal replacement have
improved survival rates in ESRD patients. This condition,
considering the high number of elderly patients on dialysis,
increases the incidence of coronary artery disease (CAD) and the
need for myocardial revascularisation in such patients. Recent
reports have shown that patients with ESRD have improved
long-term outcomes when treated surgically compared to
percutaneous procedures.
11,12
Cardiac surgery can be performed
with acceptable results in dialysis-dependent patients.
5-7,13
In
our study, the in-hospital mortality rate was 24.5%, and it was
acceptable for patients with a high EuroSCORE.
After CABG, complications develop more often in patients
with ESRD.
14
Sternal wound infection and pneumonia are
common complications that increase the risk of mortality. In
ESRD patients, the in-hospital mortality rate of cardiac surgery
varies from zero to 36.7%.
9,13
In chronic renal disease, Herzog
et
al.
9
declared an in-hospital mortality rate of 8.6% and two-year
mortality rate of 44% after surgery.
Interestingly, postoperative pneumonia was higher in OPCAB
patients in our study. This may have been because of our patient
selection, since we performed the OPCAB procedure particularly
in patients with severe lung disease. Although patients had severe
pulmonary disease in group 2, the in-hospital mortality rate was
lower. In this regard, we highlight that, from the randomised-
groups statistical analysis, the OPCAB procedure may be more
favourable.
Several studies have shown that an increased risk of
complications were associated with the use of CPB, decreased
leukocyte chemotaxis and leukopaenia, and difficulty in
maintaining fluid–electrolyte balance.
15,16
OPCAB is an alternative
method that could improve surgical morbidity and mortality
rates in dialysis-dependent patients with CAD. The OPCAB
procedure prevents the inflammatory and destructive effects of
CPB and improves short-term cardiac haemodynamics.
17-19
Improvements in technology for cardiac stabilisation and
increased experience with heart positioning have allowed
surgeons to perform routine complete off-pump revascularisation
in three-vessel coronary artery disease, especially in patients with
multiple co-morbidities. OPCAB surgery improves short-term
mortality rates in patients with ESRD.
8,20
While the in-hospital
mortality rate of OPCAB was between zero and 1.7% in some
studies, the rate for the ONCAB procedure was reported as
14.7–17.2%.
8,21
Potential benefits of off-pump surgery include
less postoperative cognitive impairment, lower incidence of renal
failure, decreased blood loss, shorter mechanical ventilation,
shorter length of ICU and hospital stay, and lower mortality
rates in high-risk groups.
22-25
Shrooff
et al
.
24
found an 8% risk
reduction of all-cause mortality in dialysis-dependent patients
with the OPCAB procedure.
Re-operation for bleeding is also a common problem in ESRD
patients.
18,19
Homeostasis disturbances, platelet dysfunction,
coagulation defects depending on uraemia, and the mechanical
stress of dialysis may be reasons for increased postoperative
bleeding. In our study, the rate of re-operation due to bleeding
was 10.5% and this may have been caused by dialysis and
its complications. In our study, 12 (10.5%) patients needed
re-operation caused by bleeding, which was higher than in
patients without renal disease.
A limitation of this study includes the disadvantages of
retrospective studies, therefore any conclusions are limited in
applicability. In this study we report on a single-centre experience
with a relatively small number of patients and short follow-up
period. Additionally, we have no definitive data for the cause of
death after hospital discharge.
Conclusion
In dialysis-dependent patients, CPB has additional risk factors
such as inflammatory effects and longer surgical times. The
inflammatory response and increased surgery and ventilation
times may cause systemic problems, particularly pulmonary
dysfunction in high-risk patients. These systemic problems
lengthen the hospitalisation period and increase mortality and
morbidity rates. The OPCAB procedure is a safe alternative with
acceptable outcomes and avoids the side effects of CPB. After
detailed investigation with coronary angiography, complete
revascularisation with the OPCAB procedure is possible in
centres with experienced surgeons. It may be the treatment of
choice in high-risk patients, using skilled surgeons.
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