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Cardiologie
Tunisienne
Les complications neurologiques après chirurgie coronaire:
étude comparative CEC versus cœur battant.
Neurological complications after coronary artery bypass
grafting: on-pump compared with off-pump
Atef Ben youssef, sarra Zairi, Zied Ghariani, refk Kasraoui, sonia ouerghi, Taher Mestiri, Tarek Kilani.
Department of Thoracic and Cardio-vascular Surgery. Abderrahmen Mami Hospital. Ariana. University of Tunis El Manar. Tunisia.
Résumé
Mots-clés
Introduction: Il est communément admis que la chirurgie coronaire sous circulation extra-corporelle
(CEC) est associée à une morbidité cérébrale en post-opératoire. La chirurgie coronaire à cœur battant
(CB) a été proposée comme une alternative acceptable avec une moindre morbidité post-opératoire.
But: Evaluer les résultats de la chirurgie coronaire à cœur battant en matière de prévention des complications neurologiques post-opératoires à travers notre pratique.
Matériel et méthodes: nous avons rapporté notre série rétrospective monocentrique de 455 patients, ayant
eu un pontage coronaire (330 sous CEC et 125 à CB) entre 2004 et 2012 dans le service de chirurgie
thoracique et cardio-vasculaire de l’hôpital Abderrahmen Mami en Tunisie. Nous avons évalué la
fréquence des lésions cérébrales post-opératoires dans le groupe CEC comparée au groupe CB.
Résultats: Parmi nos patients, nous avons rapporté en post-opératoire: un accident vasculaire cérébral
dans 7 cas (5 sous CEC et 2 à CB), une agitation dans 13 cas (11 sous CEC et 2 à CB), un trouble visuel
transitoire dans 4 cas sous CEC, un accident ischémique transitoire dans 6 cas (5 sous CEC et 1 à CB) et
des convulsions dans 4 cas (3 sous CEC et 1 à CB).
Conclusion: Bien que la différence entre les deux groupes n'était pas statistiquement significative, les
patients à CB ont eu un meilleur résultat en post-opératoire concernant les complications cérébrales. Les
complications neurologiques cérébrales rapportées chez les patients inclus dans ce groupe étaient
corrélées avec un terrain spécifique plutôt que le pontage coronaire en lui-même.
Chirurgie coronaire;
accident vasculaire
cérébral; agitation;
circulation extracorporelle; cœur battant.
Summary
Keywords
Introduction: It is commonly admitted that on-pump coronary artery bypass grafting (CABG) is associated with post-operative cerebral morbidity. Off-pump coronary artery bypass has been suggested as an
acceptable alternative with less post-operative morbidity.
Aim: to assess the efficiency of off-pump coronary surgery in avoiding post-operative cerebral injury
through our practice.
Material and methods: we reported our single center retrospective series of 455 patients, which had
undergone a coronary artery bypass grafting (330 cases on-pump and 125 off-pump) between 2004 and
2012 in the thoracic and cardio-vascular surgery department of Abderrahmen Mami hospital in Tunisia.
We assessed the occurrence of post-operative cerebral injury in the on-pump group compared with the
off-pump group.
Results: Among our patients, we reported in the post-operative course: a stroke in 7 cases (5 on-pump
and 2 off-pump), agitation in 13 cases (11 on-pump and 2 off-pump), visual impairment in 4 on-pump
operated patients, transient ischemic attack in 6 cases (5 on-pump and 1 off-pump) and seizures in 4 cases
(3 on-pump and 1 off-pump).
Conclusion: Although the difference between the two groups was not statistically relevant, off-pump
patients had a better post-operative outcome regarding cerebral injuries. Cerebral complications reported
in patients enrolled in this group were correlated with a specific condition rather than with the coronary
artery bypass itself.
Coronary bypass; stroke;
agitation; on-pump; offpump.
Correspondance
Dr. Ben Youssef Atef
Department of Thoracic and Cardio-vascular Surgery. Abderrahmen
Mami Hospital. Ariana. University of Tunis El Manar. Tunisia.
Cardiologie Tunisienne - Volume 09 N°04 - 4eme Trimestre 2013 -243-246
45
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IntroductIon
since the first successful use of the heart lung machine
by dr. gibbon Jr in 1953, coronary artery bypass grafting
on-pump has been developing to become the standard
for the management of multi-vessel coronary disease [1].
during the past sixty years, coronary artery disease has
widely benefited from the technological advances with
the great improvement in anesthetic management. Thus,
operative mortality had continuously declined, while
operative morbidity has been rising for many reasons.
More complicated elderly cases, with advanced coronary
artery disease and several co-morbidities are
encompassed in surgical management [2]. Post-operative
morbidity after coronary artery bypass grafting such as
post-operative infarction, left ventricular dysfunction
and neurological complications are of a real concern, but
cerebral complications are the most devastating [3]. offpump coronary artery bypass has been suggested as an
acceptable alternative with less post-operative morbidity. Through our practice, in a single cardio-thoracic
department in Tunisia, we aimed to assess the efficiency
of off-pump coronary surgery in avoiding post-operative
cerebral injury.
MAterIAl And Methods
We reported our single center retrospective series of 455
patients, which had undergone a coronary artery bypass
grafting (330 cases on-pump and 125 off-pump) between
2004 and 2012 in the thoracic and cardio-vascular
surgery department of abderrahmen Mami hospital in
Tunisia. We assessed the occurrence of post-operative
cerebral injury in the on-pump group compared with the
off-pump group.
The records of all our patients were reviewed and postoperative neurological disorders were classified as in
current literature [4] in two types. Focal cerebral lesions
(such as stroke, transient ischemic attack) and anoxic
encephalopathy (coma) were included in type i.
seizures, temporary visual impairment and diffuse
neuropsychological sequellae (such as cognitive dysfunction, memory disorders, and delirium) were included in
type ii.
Computer software (sPss for iBM version 20) was used for
processing data. The Chi2 test was used to compare
qualitative variables. in case of no validity, the bilateral
Fisher exact test was used. The difference was considered significant if p<0.05.
results
a total of 455 patients underwent a coronary artery
bypass grafting in our department during 9 years, with
330 patients on-pump and 125 off-pump. The mean age
was comparable in both groups with 61.73 years in the
on-pump group and 60.65 years in the off-pump group.
History of previous stroke was found in 11 patients (3.3%)
in the on-pump group and in 5 patients (4%) in the offpump group. ultra-duplex sonography of the carotid
arteries revealed significant stenosis which was operated
at the same procedure in 6 cases (1.8%) on-pump and 3
cases off-pump (2.4%). neurological complications were
reported in 34 cases (7.47%): 27 on-pump (8.18%) and 7
off-pump (5.6%). The characteristics of these patients
are summarized in table i.
in the off-pump group, partial aortic clamping was used
in 58 cases, among them 4 cases (6.9%) had neurological
complications. sixty-seven patients from the off-pump
group were operated with the no-touch technique,
among them 3 patients (4.47%) presented post-operative
neurological complications.
Post-operative stroke was reported in 3 cases (2.4%) offpump (Table ii).
Table 1 : The characteristics of the patients which developed post-operative neurological complications.
Variables
On-pump
Total
Off-pump
Aortic No-touch
Aortic Partial-clamping
%
Diabetes
11
1
2
14 (41.2%)
Hypertension
14
0
1
15 (44.1%)
Atherosclerosis
2
0
0
2 (5.9%)
Dyslipemia
8
1
1
10 (29.4%)
1 (2.9%)
History Of Stroke
0
0
1
Ultra-duplex Sonography
0
1
0
1 (2.9%)
Left Ventricular Dysfunction
4
1
1
6 (17.6%)
0
0
1 (2.9%)
Preoperative Arrhythmia
1
Intra-operative IABP
0
0
1
1 (2.9%)
Post-operative deaths
5
0
1
6 (35.3%)
4eme Trimestre 2013
Cardiologie Tunisienne 46
A. Ben Youssef & al.
Table 2 : Neurological complications in on-pump and offpump patients.
Complication
On-pump Off-pump
Total
TYPE I
Post-operative stroke
4 (1.21%)
3 (2.4%)
7 (1.53%)
Transient ischemic attack
5 (1.51%)
1 (0.8%)
6 (1.3%)
Agitation
11 (3.3%)
2 (1.6%)
13 (2.85%)
Temporary visual impairment
4 (1.21%)
0
4 (0.87%)
Seizures
3 (0.9%)
1 (0.8%)
4 (0.87%)
27 (8.18%) 7 (5.6%)
34 (7.47%)
TYPE II
Total
The first patient had coronary artery bypass grafting
with a no-touch technique but underwent internal
carotid endarterectomy during the same procedure. For
the two other patients, 2 coronary arteries were grafted
with partial aortic clamping and intra-aortic balloon
pump counter-pulsation was used in one case intraoperatively. in the on-pump group, post-operative stroke
was reported in 4 patients (1.21%). among them, there
were no previous history of stroke and their preoperative carotid duplex ultra-sonographies were
normal. one patient had a bilateral visual impairment
pre-operatively, secondary to stenosis of the right
posterior cerebral artery without ischemic lesion at brain
CT-scan and no significant stenosis in the internal carotid
arteries.
six patients presented a transient ischemic attack (5 onpump (1.51%) and 1 off-pump (0.8%)). These patients had
no previous history of stroke. Their pre-operative duplex
ultra-sonographies were normal and postoperative brain
CT-scan 24 hours after the attack was normal in all the
cases. Partial aortic clamping was used for the patient
operated off-pump, which had a history of dyslipemia.
Type ii complications, such as seizures were seen in 4
cases (3 on-pump and 1 off-pump). in the on-pump
patients, there were no past history of stroke, ultraduplex sonography and CT-scan were normal. Postoperative hypoxic pneumonia and hyponatremia were
the cause, each in one case. The off-pump patient, had
a history of stroke, with normal duplex and sequellar
lesions at CT.
Visual impairment was seen only in the on-pump group,
in 4 cases (1.21%). it was transient with complete
recovery within three days. There were no history of
previous ocular problems, but 2 patients had hypertension. ophthalmic examination and CT-scan were normal
in all cases.
agitation was the most frequent complication, reported
in 13 cases: 11 on-pump (3.3%) and 2 off-pump (1.6%).
among these patients there was no past history of
seizures or drug addiction. duplex ultra-sonography and
4eme Trimestre 2013
brain CT-scan were normal in all patients. Post-operative
sepsis was the cause in 4 cases on-pump (1.21%) and 1
case off-pump (0.8%).
in the post-operative course we reported 6 deaths: 5 onpump (1.51%) (4 patients with agitation and 1 patient
with stroke) and 1 off-pump (0.8%) (1 patient with
agitation). The five patients with agitation died from
severe sepsis. The patient which presented postoperative stroke died from severe left-ventricular
dysfunction.
dIscussIon
Post-operative cerebral complications after coronary
artery bypass grafting are the most devastating. They
are responsible for increase in the length of hospital
stay, with increased medical expenses and high rates of
hospital mortality [3].
The rate of neurological complications is different
according to authors, with type i complications such as
stroke, being the most catastrophic and costly [5].
The incidence of post-operative stroke varies in literature from 1.5 to 6% [6], with a mortality rate of 21% and
a mean hospital stay of 25 days [4].
The incidence of stroke in our series was comparable to
literature with a rate of 1.53%.
Patients at high risk of neurological complications are:
older patients, patients with prior history of cerebrovascular events, recent myocardial infarction, or those
presenting with carotid artery or aorto-iliac arterial
disease [3].
reported risk factors of neurological complications after
cardiac surgery are not identical for both types. For type
i complications, history of stroke, diabetes, the use of
intra-aortic balloon-pump and ascending aortic
atheroma are significant risk factors, with aortic
atheroma being the most determinant [4].
among our patients, post-operative stroke was reported
in 2.4% in off-pump patients (3 cases). The first patient
underwent coronary artery bypass grafting with a notouch technique and had internal carotid endarterectomy during the same procedure. in the two other
patients, 2 coronary arteries were grafted with partial
aortic clamping and intra-aortic balloon pump was used
in one case. in the on-pump group, there was no history
of stroke. stenosis of the right posterior cerebral artery
with bilateral visual impairment pre-operatively, with no
ischemic lesion at brain CT-scan and no significant
stenosis in the internal carotid arteries was reported in
one case.
Type ii complications are correlated with systolic
hypertension, respiratory problems and excessive
alcohol consumption [4].
during on-pump coronary artery bypass grafting, aortic
cannulation, aortic cross clamping and platelet
aggregate secondary to the pump are causes of high risk
Cardiologie Tunisienne 47
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of emboli, with stroke being the most severe complication [7].
on-pump group patients in our series, which presented
post-operative stroke, didn’t have associated risk predictors in their background. The use of the heart-lung
machine was completely responsible for their postoperative neurological outcome.
during the past decades, taken that adverse neurologic
events were specifically related to the use of extracorporeal cardiopulmonary bypass, techniques of off-pump
surgery were developed to avoid the use of cardiopulmonary bypass and off-pump surgery was suggested to
decrease the risk of stroke [8]. a recent meta-analysis
confirmed the difference and showed statistical significance [9].
However, in off-pump surgery with partial aortic
clamping, the same ascending aorta manipulations are
used. Therefore, there is no difference in stroke rate
when compared with on-pump procedures [10].
Therefore, off-pump coronary artery bypass grafting
with total arterial revascularization “no touchtechnique”, has been proposed as a safer alternative
with better neurological outcomes and less cerebral
morbidity [10].
conclusIon
although the difference between the two groups was not
statistically relevant, off-pump patients had a better
post-operative outcome regarding cerebral injuries.
Cerebral complications reported in patients enrolled in
this group were correlated with aortic manipulation and
specific conditions rather than with the coronary artery
bypass itself.
aortic no-touch technique should be applied whenever
possible to avoid cerebral morbidity.
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results from the danish on-pump versus off-pump randomization study. Circulation 2012; 125:2431-9.
3. Hogue CW Jr, Palin Ca, arrowsmith Je. Cardiopulmonary
bypass management and neurologic outcomes: an evidence-based appraisal of current practices. anesth analg
2006; 103:21-37.
4. roach gW, Kanchuger M, Mangano CM, et al. adverse cerebral outcomes after coronary bypass surgery. Multicenter
study of Perioperative ischemia research group and the
ischemia research and education Foundation investigators.
n engl J Med 1996; 335:1857-63.
5. Veerakul g, Visudharom K. Cerebral complications in
conventional coronary bypass graft surgery. The Bangkok
Medical Journal 2011; 2:58-66.
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Ma, Bavaria Je, rahmouni H, Kuersten B, Wiegers s, Mc
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garvey Ml, Woo JY, Pochettino aa, Melhem er. Clinically
silent cerebral ischemic events after cardiac surgery: their
incidence, regional vascular occurrence and procedural
dependence. ann Thorac surg 2006; 81:2160-6.
7. djaiani g, Fedorko l, Borger M, Mikulis d, Carroll J, Cheng
d, Karkouti K, Beattie s, Karski J. Mild to moderate atheromatous disease of the thoracic aorta and new ischemic
brain lesions after conventional coronary artery bypass
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8. Matata BM, sosonowski aW, galinanes M. off-pump bypass
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