APPENDIX
Supplemental Methods
Literature Search Strategy
Electronic searches were performed using Ovid Medline, Pubmed, Cochrane Central
Register of Controlled Trials (CCTR), Cochrane Database of Systematic Reviews (CDSR), ACP
Journal Club, and Database of Abstracts of Review of Effectiveness (DARE), from their dates of
inception to April 2016. To achieve maximum sensitivity of the search strategy, we combined
the terms “anaortic”, “no-touch”, “aorta”, “off-pump”, “coronary artery bypass grafting”,
“proximal anastomosis”, “stroke”, “neurological complications”, “cerebral ischemia”, and
“cerebrovascular accident” as both text keywords and exploded MeSH headings where possible.
For an additional review of randomized and non-randomized studies comparing the use of single
versus double aortic clamp in on-pump CABG, the terms “single”, “double”, “multiple”,
“partial-occluding”, “clamp”, “cross-clamp”, “clamping”, “on-pump”, “coronary artery bypass
grafting”, “stroke”, “neurological complications”, “cerebral ischemia”, and “cerebrovascular
accident” were combined as both text keywords and exploded MeSH headings where possible.
Two authors (D.F.Z and M.S) performed the search independently, and any discrepancies were
resolved by discussion. The reference lists of all retrieved articles were reviewed for further
identification of potentially relevant studies, assessed using the inclusion and exclusion criteria.
Selection Criteria
Studies specifying the use of single or double (partial-occluding) aortic clamp in onpump CABG were included in separate network and pairwise meta-analyses. Minimally invasive
direct CABG, often indicated in single-vessel disease, and on-pump beating-heart CABG were
1
excluded. When institutions published duplicate studies with accumulating numbers of patients
or increased lengths of follow-up, only the most complete reports were included for quantitative
assessment. All publications were limited to those involving human subjects. Abstracts, case
reports, conference presentations, editorials, reviews, and expert opinions were excluded.
Data Extraction and Critical Appraisal
Because quality scoring is controversial in meta-analyses of observational studies, two
reviewers (D.F.Z and M.S) independently appraised each article included in our analysis
according to a critical review checklist of the Dutch Cochrane Centre proposed by MOOSE (1).
The key points of this checklist include: (I) clear definition of study population; (II) clear
definition of outcomes and outcome assessment; (III) independent assessment of outcome
parameters; (IV) sufficient duration of follow-up; (V) no selective loss during follow-up; and
(VI) important confounders and prognostic factors identified.
Outcomes
Stroke was defined as cerebrovascular events occurring in the postoperative period
unresolved within 24 hours (2). Where available, stroke was diagnosed by a neurologist and
confirmed by computed tomographic (CT) scanning or nuclear magnetic resonance imaging
(MRI) (3). Operative mortality was defined as any death occurring within 30 days of the
procedure (4,5). Peri-operative myocardial infarction was identified by the presence of a new Q
wave on the electrocardiogram, a maximal serum creatine kinase MB isoenzyme level of >100
IU/L, or new wall motion abnormalities on echocardiography (4,5). Renal failure was defined as
a >50 mM post-operative increase serum creatinine, doubling or greater increase in creatinine
over the pre-operative value, or new requirement for dialysis (4,5). Bleeding complication was
defined as the need for redo-sternotomy in the presence of more than 500 mL of blood from
2
chest tubes within the first hour, more than 400mLwithin the second hour, more than 300 mL
within the third hour, or total bleeding greater than 1000 mL within four hours (6). Postoperative atrial fibrillation was defined as new-onset atrial fibrillation following the operation
(7,8).
Statistical Analysis
Both random and fixed effects analyses were conducted for the Bayesian Markov chain
Monte-Carlo
model.
Predictive
distributions
(informative
priors)
for
between-study
heterogeneity were applied to random effects analyses (9). All-cause mortality informative priors
were chosen based on non-pharmacological interventions with objective outcomes (10). The
random effects model was adopted for final interpretation of results for its more conservative
estimates. Convergence was achieved at 20,000 iterations for all outcomes and lack of
autocorrelation was checked and confirmed. A further 30,000 iterations were taken after
discarding the burn-in simulation. The variability of results across trials over and above chance
(heterogeneity [τ2]) was evaluated, with an τ2 estimate of 0.04 interpreted as a low, 0.14 as a
moderate, and 0.40 as a high degree of heterogeneity (11).
Comparison with conventional pairwise meta-analysis was also performed for evaluation
of model consistency. Relative risk was chosen as a summary statistic with both fixed and
random effects models tested. The Mantel–Haenszel test was used to combine discrete data.
Inverse variance-weighted averages were used for continuous data and logarithmic risk ratios
(RR). The random effects model was used to take into account the possible clinical diversity and
methodological variation amongst studies. All P values were two-sided. Additional tests include:
χ2 to test heterogeneity between trials; I2 to estimate the percentage of total variation across
studies due to heterogeneity rather than chance. I2 can be calculated as follows: I2 =
3
100%×(Q−df)/Q (where Q represents Cochrane’s measure of heterogeneity and df the degrees of
freedom). Heterogeneity is substantial when I2 > 50%. Analysis for potential confounding factors
was not performed due to the lack of raw data. Statistical analysis was conducted using Review
Manager Version 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen).
The Egger regression asymmetry test was performed for quantitative assessment of
publication bias (12). Regression of the standardized effect estimates was tested against precision
to determine whether the gradient significantly deviates from zero. Logarithmic summary
estimate (risk ratio) and standard error were analyzed. Publication bias is significant when P <
0.05. Statistical analysis was conducted using Stata Statistical Software 14 (College Station, TX)
with the metabias module.
Supplemental Results
Additional analyses
Five studies with 15254 patients were included in a subgroup analysis evaluating
anOPCABG (2910 patients), OPCABG-PC (3756 patients), single-aortic clamp on-pump CABG
(2512 patients), and double-clamp on-pump CABG (6076 patients). Definitions of aortic
clamping technique are reported in Online Table 3. Three studies (6,13,14) utilized the singleclamp technique, three studies (14-16) utilized the double-clamp technique (with partialoccluding clamp). Four studies (2,4,17,18) did not specify the aortic clamping strategy and were
excluded from the subgroup analysis. The evidence network for the subgroup analysis of
postoperative stroke outcomes following anOPCABG, OPCABG-PC, and on-pump CABG with
single or double aortic clamp is shown in Online Figure 6A.
anOPCABG was associated with a reduction of 81% in the 30-day risk of stroke
compared with on-pump CABG using a double-clamping technique (OR 0.19, 95% CI 0.08 –
4
0.38), 77% compared with on-pump CABG using a single-clamping technique (OR 0.23, 95%
CI 0.09 – 0.50), and 66% compared with OPCABG-PC (OR 0.34, 95% CI 0.15 – 0.71) (Online
Figure 6B). OPCABG-PC was associated with a 43% reduction in stroke risk compared with onpump CABG using a double-clamping technique (OR 0.57, 95% CI 0.32 – 0.87).
There were no significant differences between single versus double aortic clamping
techniques in on-pump CABG (OR 0.70, 95% CI 0.30 – 1.39) or between OPCABG-PC and onpump CABG with a single aortic cross-clamp (OR 0.81, 95% CI 0.41 – 1.68). Heterogeneity was
moderate (τ2 = 0.16). The league table is shown in Online Figure 6C. Bayesian Markov chain
Monte-Carlo modeling demonstrated that anOPCABG had the highest probability of having the
lowest rate of stroke (SUCRA 99.9%), followed by OPCABG-PC (61.3%), on-pump CABG
using a single-clamping technique (29.6%), and on-pump CABG using a double-clamping
technique (9.2%) (Online Figure 6D).
To confirm model consistency and further evaluate the outcome comparing single versus
double-clamping techniques in on-pump CABG, an additional review of all randomized and nonrandomized studies was performed. After application of the inclusion and exclusion criteria, nine
(19-27) relevant articles were included in this additional pairwise meta-analysis, including five
matched or randomized (19,21,24,26,27) and four unmatched (20,22,23,25) trials. A total of
5153 patients undergoing on-pump CABG were included for analysis with 2559 receiving single
and 2594 receiving double aortic clamps. No significant differences were detected between
single or double aortic clamp use in the overall pairwise meta-analysis (1.1% vs 1.7%; RR 0.7,
95% CI 0.5–1.2; P = 0.19; I2 = 0%) (Online Figure 7), in matched or randomized studies only
(1.2% vs 1.5%; RR 0.8, 95% CI 0.5–1.5; P = 0.52; I2 = 0%) (Online Figure 7.1), or in unmatched
studies only (1.1% vs 1.9%; RR 0.6, 95% CI 0.3–1.3; P = 0.19; I2 = 0%) (Online Figure 7.2).
5
The outcome following single versus double-clamping techniques in on-pump CABG was
comparable between the subgroup network analysis (OR 0.70, 95% CI 0.30 – 1.39) and
additional review and pairwise analysis (RR 0.7, 95% CI 0.5–1.2).
6
Supplemental References
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Stroup DF, Berlin JA, Morton SC et al. Meta-analysis of observational studies in
epidemiology: a proposal for reporting. Meta-analysis Of Observational Studies in
Epidemiology (MOOSE) group. JAMA 2000;283:2008-12.
2.
Moss E, Puskas JD, Thourani VH et al. Avoiding aortic clamping during coronary artery
bypass grafting reduces postoperative stroke. J Thorac Cardiovasc Surg 2015;149:17580.
3.
Matsuura K, Mogi K, Sakurai M, Kawamura T, Takahara Y. Medium-term neurological
complications after off-pump coronary artery bypass grafting with and without aortic
manipulation. Coron Artery Dis 2013;24:475-80.
4.
Misfeld M, Potger K, Ross DE et al. "Anaortic" off-pump coronary artery bypass grafting
significantly reduces neurological complications compared to off-pump and conventional
on-pump surgery with aortic manipulation. Thorac Cardiovasc Surg 2010;58:408-14.
5.
Leacche M, Carrier M, Bouchard D et al. Improving neurologic outcome in off-pump
surgery: the "no touch" technique. Heart Surg Forum 2003;6:169-75.
6.
Lemma MG, Coscioni E, Tritto FP et al. On-pump versus off-pump coronary artery
bypass surgery in high-risk patients: operative results of a prospective randomized trial
(on-off study). J Thorac Cardiovasc Surg 2012;143:625-31.
7.
Manabe S, Fukui T, Miyajima K et al. Impact of proximal anastomosis procedures on
stroke in off-pump coronary artery bypass grafting. J Card Surg 2009;24:644-9.
8.
Frendl G, Sodickson AC, Chung MK et al. 2014 AATS guidelines for the prevention and
management of perioperative atrial fibrillation and flutter for thoracic surgical
procedures. J Thorac Cardiovasc Surg 2014;148:e153-93.
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9.
Turner RM, Jackson D, Wei Y, Thompson SG, Higgins JPT. Predictive distributions for
between-study heterogeneity and simple methods for their application in Bayesian metaanalysis. Stat Med 2015;34:984-998.
10.
Turner RM, Davey J, Clarke MJ, Thompson SG, Higgins JPT. Predicting the extent of
heterogeneity in meta-analysis, using empirical data from the Cochrane Database of
Systematic Reviews. Int J Epidemiol 2012.
11.
Stettler C, Allemann S, Wandel S et al. Drug eluting and bare metal stents in people with
and without diabetes: collaborative network meta-analysis. BMJ 2008;337.
12.
Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a
simple, graphical test. BMJ 1997;315:629-34.
13.
Kim KB, Kang CH, Chang WI et al. Off-pump coronary artery bypass with complete
avoidance of aortic manipulation. Ann Thorac Surg 2002;74:S1377-82.
14.
Calafiore AM, Di Mauro M, Teodori G et al. Impact of aortic manipulation on incidence
of cerebrovascular accidents after surgical myocardial revascularization. Ann Thorac
Surg 2002;73:1387-93.
15.
Kapetanakis EI, Stamou SC, Dullum MK et al. The impact of aortic manipulation on
neurologic outcomes after coronary artery bypass surgery: a risk-adjusted study. Ann
Thorac Surg 2004;78:1564-71.
16.
Patel NC, Deodhar AP, Grayson AD et al. Neurological outcomes in coronary surgery:
independent effect of avoiding cardiopulmonary bypass. Ann Thorac Surg 2002;74:4005; discussion 405-6.
8
17.
Emmert MY, Seifert B, Wilhelm M, Grunenfelder J, Falk V, Salzberg SP. Aortic notouch technique makes the difference in off-pump coronary artery bypass grafting. J
Thorac Cardiovasc Surg 2011;142:1499-506.
18.
Izumoto H, Oka T, Kawazoe K, Ishibashi K, Yamamoto F. Individualized off-pump all
internal thoracic artery revascularization. Ann Thorac Cardiovasc Surg 2009;15:155-9.
19.
Araque JC, Greason KL, Li Z et al. On-pump coronary artery bypass graft operation: Is
one crossclamp application better than two? J Thorac Cardiovasc Surg 2015;150:145-9.
20.
Gasparovic H, Borojevic M, Malojcic B, Gasparovic K, Biocina B. Single aortic
clamping in coronary artery bypass surgery reduces cerebral embolism and improves
neurocognitive outcomes. Vasc Med 2013;18:275-81.
21.
Hammon JW, Stump DA, Butterworth JF et al. Single crossclamp improves 6-month
cognitive outcome in high-risk coronary bypass patients: the effect of reduced aortic
manipulation. J Thorac Cardiovasc Surg 2006;131:114-21.
22.
Ates M, Yangel M, Gullu AU, Sensoz Y, Kizilay M, Akcar M. Is single or double aortic
clamping safer in terms of cerebral outcome during coronary bypass surgery? Int Heart J
2006;47:185-92.
23.
Sinatra R, Capuano F, Santaniello E, Tonelli E, Roscitano A. Occluding clamp technique
during coronary artery bypass grafting: single or double-clamp technique? Ital Heart J
2004;5:450-2.
24.
Tsang JC, Morin JF, Tchervenkov CI, Platt RW, Sampalis J, Shum-Tim D. Single aortic
clamp versus partial occluding clamp technique for cerebral protection during coronary
artery bypass: a randomized prospective trial. J Card Surg 2003;18:158-63.
9
25.
Grega MA, Borowicz LM, Baumgartner WA. Impact of single clamp versus double
clamp technique on neurologic outcome. Ann Thorac Surg 2003;75:1387-91.
26.
Dar MI, Gillott T, Ciulli F, Cooper GJ. Single aortic cross-clamp technique reduces S100 release after coronary artery surgery. Ann Thorac Surg 2001;71:794-6.
27.
Bertolini PS, F.; Montalbano, G., Pessotto, R., Mazzucco, A. Single aortic cross-clamp
technique in coronary surgery: a prospective randomized study. Eur J Cardiothorac Surg
1997;12:413-418.
10
Supplemental Figure 1: Funnel plot for assessment of publication bias in network metaanalysis of coronary artery bypass grafting with and without manipulation of the aorta.
Outcomes shown for (A) anOPCABG vs CABG; (B) anOPCABG vs OPCABG-PC. The logit
event rate for outcomes (horizontal axis) is presented against the standard error (SE) of the log of
logit event rate (vertical axis). SE inversely corresponds to study size. Asymmetry of the plot
may indicate publication bias. RR, risk ratio.
11
Supplemental Figure 2: Forest plots for coronary artery bypass grafting with and without
manipulation of the aorta. Outcomes shown for (2.1) stroke, (2.2) mortality, (2.3) myocardial
infarction, (2.4) renal failure, (2.5) bleeding complications, and (2.6) atrial fibrillation following
anOPCABG vs CABG in pairwise meta-analysis of coronary artery bypass grafting with and
without manipulation of the aorta. anOPCABG, anaortic off-pump coronary artery bypass
grafting; CABG, coronary artery bypass grafting; RR, risk ratio; CI, confidence interval; df,
degrees of freedom; M-H, Mantel-Haenszel.
12
13
Supplemental Figure 3: Forest plots for coronary artery bypass grafting with and without
manipulation of the aorta. Outcomes shown for (3.1) stroke, (3.2) mortality, (3.3) myocardial
infarction, (3.4) renal failure, (3.5) bleeding complications, and (3.6) atrial fibrillation risk
following anOPCABG vs OPCABG-PC in pairwise meta-analysis of coronary artery bypass
grafting with and without manipulation of the aorta. anOPCABG, anaortic off-pump coronary
artery bypass grafting; OPCABG-PC, off-pump coronary artery bypass grafting with partial
clamp; RR, risk ratio; CI, confidence interval; df, degrees of freedom; M-H, Mantel-Haenszel.
14
15
Supplemental Figure 4: Forest plots for coronary artery bypass grafting with and without
manipulation of the aorta. Outcomes showing stroke risk following OPCABG-HS vs CABG in
pairwise meta-analysis of off-pump coronary artery bypass grafting with and without
manipulation of the aorta. OPCABG-HS, off-pump coronary artery bypass grafting with the
Heartstring system; CABG, coronary artery bypass grafting; RR, risk ratio; CI, confidence
interval; df, degrees of freedom; M-H, Mantel-Haenszel.
16
Supplemental Figure 5: Forest plots for coronary artery bypass grafting with and without
manipulation of the aorta. Outcomes shown for (5.1) ICU length of stay after anOPCABG vs
CABG, (5.2) hospital length of stay after anOPCABG vs OPCABG-PC, and (5.3) ICU length of
stay after anOPCABG vs OPCABG-PC. ICU, intensive care unit; anOPCABG, anaortic offpump coronary artery bypass grafting; OPCABG-PC, off-pump coronary artery bypass grafting
with partial clamp; CABG, coronary artery bypass grafting; RR, risk ratio; CI, confidence
interval; df, degrees of freedom; IV, inverse variance.
17
Supplemental Figure 6: Network meta-analysis of postoperative stroke following coronary
artery bypass grafting with different on-pump aortic clamping techniques. (A) Network
diagram. The number of patients in each group is proportional to the size of the circle. The
number of direct comparisons is represented by the width of the connecting line. A, anaortic offpump coronary artery bypass grafting; PC, off-pump coronary artery bypass grafting with partial
clamp; CS, on-pump coronary artery bypass grafting with single clamp; CD, on-pump coronary
artery bypass grafting with double clamp. (B) Forest plot. anOPCABG, anaortic off-pump
coronary artery bypass grafting; OPCABG-PC, off-pump coronary artery bypass grafting with
partial clamp; CABG-Single, on-pump coronary artery bypass grafting with single clamp;
CABG-Double, on-pump coronary artery bypass grafting with double clamp; OR, odds ratio; CI,
confidence interval; Inform, informative prior. (C) League table (odds ratios and 95% confidence
intervals). Odds ratio <1 means the treatment in top left is better. (D) Rankogram showing the
likelihood of reducing postoperative stroke. SUCRA, surface under the cumulative ranking.
18
19
Supplemental Figure 7: Forest plots for on-pump coronary artery bypass grafting with
single or double aortic clamp. Stroke outcomes shown for (7.1) matched or randomized trials,
(7.2) unmatched trials. CS, on-pump coronary artery bypass grafting with single clamp; CD, onpump coronary artery bypass grafting with double clamp.; RR, risk ratio; CI, confidence interval;
df, degrees of freedom; M-H, Mantel-Haenszel.
20
Supplemental Figure 8: Forest plots for coronary artery bypass grafting with and without
manipulation of the aorta. Outcomes shown for (8.1) stroke, (8.2) mortality, (8.3) myocardial
infarction, (8.4) renal failure, (8.5) bleeding, and (8.6) atrial fibrillation risk following combined
off-pump techniques vs on-pump CABG in pairwise meta-analysis of coronary artery bypass
grafting with and without manipulation of the aorta. Off-pump, combined off-pump coronary
artery bypass grafting techniques; On-pump, on-pump coronary artery bypass grafting; RR, risk
ratio; CI, confidence interval; df, degrees of freedom; M-H, Mantel-Haenszel.
21
22
Supplemental Table 1. MOOSE quality assessment for included studies in network meta-analysis of coronary artery bypass grafting
with and without manipulation of the aorta.
Important
Clear definition Clear definition of
Independent
Sufficient
Sufficient No selective confounders and
of study
outcomes and
assessment of
duration of
sample
loss during prognostic factors
First author population
outcome assessment
outcome parameters follow-up
size
follow-upd identified
Moss
Yes
Yes
Nod
Yes
Yes
Yes
Yes
Lemma
Noa
Yes
Yes
Yes
Nof
Yes
Yes
Matsuura
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Emmert
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Misfield
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Manabe
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Izumoto
Yes
Noc
Nod
Yes
Nof
Yes
Yes
Lev-Ran
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Kapetanakis Yes
Yes
Yes
Yes
Yes
Yes
Yes
Leacche
Yes
Nod
Yes
Nof
Yes
Yes
Yes
23
Patel
Yes
Yes
Nod
Yes
Yes
Yes
Yes
Kim
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Calafiore
Yes
Yes
Yes
Yes
Yes
Yes
Yes
a
anOPCABG population not explicitly stated in article – data acquired from correspondence with author; bdetailed definition and
assessment of stroke shown in Supplementary Table 2; cdefinition of stroke not adequately described; ddiagnosis of stroke not
independently confirmed by a neurologist; eall outcomes were 30-day or post-operative; fnumber of patients in anOPCABG is less
than 100
24
Supplemental Table 2. Usage of epi-aortic ultrasonography and definition of stroke for network meta-analysis of coronary artery
bypass grafting with and without manipulation of the aorta.
Epi-aortic ultrasound
First author
Moss
(mean grade )
Stroke definition and assessment
Performed in majority
Any confirmed neurologic deficit of abrupt onset caused by a disturbance in blood
of patientsa
supply to the brain that did not resolve within 24 hours
anOPCABG
2.13
CABG
1.44
OPCABGPC
HS
1.35
2.38
A neurological deficit confirmed by brain MRI or CT; diagnosed by neurologist and
Matsuura
NR
radiologist
25
Lemma
NR
Neurologic deficit lasting>24 hours with positive computed tomography findings
A new neurologic deficit that appears and remains evident for more than 24 hours after
on-set and occurs during or after the CABG procedure; diagnosed before discharge;
diagnosis confirmed by neurologist and brain imaging; transient ischemic attacks,
Emmert
Not implemented
intellectual impairment, confusion, or irritation excluded
Focal or global neurological deficits evident after emergence from anesthesia and
diagnosed by neurologist and confirmed by computed tomographic scanning (CT) or
nuclear magnetic resonance imaging (MRI); a prolonged or permanent neurological
Misfield
Manabe
anOPCABG
OPCABG-
Routinely performed
deficit persisting for more than 72 hours
Conducted in patients
Any new global or focal neurological deficit; confirmed by computed tomography or
receiving aortic
magnetic resonance imaging (MRI); diagnosed definitively by an attending neurologist;
proximal anastomosisb
reversible ischemic events excluded
Severe
Moderate
26
PC
HS
Izumoto
Less than mild
NR
NR
Any global or focal neurologic deficit evident after emergence from anesthesia and
categorized as either permanent or reversible (transient ischemic attacks and prolonged
reversible ischemic neurologic deficit); all neurologic events were evaluated by
Lev-Ran
Performed selectively
neurologist and further assessed by computed tomographic scan
Postoperatively occurring new focal neurologic deficit; persisting for longer than 72
hours after onset; diagnosed by clinical findings; confirmed by neurologist or brain
imaging (head computed tomography or magnetic resonance imaging); noted before
Not performed
Kapetanakis
discharge or death; transient neurologic events, intellectual impairment, and
confusional or irritable states excluded
A new focal neurologic deficit confirmed by clinical findings and computed
Leacche
Not routinely used
tomographic scan; stroke defined as postoperative if occurred after a normal
27
postoperative period
A new focal neurologic deficit or a comatose state occurring postoperatively that
persisted for more than 24 hours after onset; noted before discharge or death; transient
neurologic events, confusional states, or intellectual impairment excluded; resident and
Patel
Not performed
consultant medical staff made the diagnosis of focal neurologic deficit
An interview and neurologic evaluation by a neurologist, carotid duplex
ultrasonography, and transcranial Doppler or magnetic resonance angiography; stroke
defined as a new and sudden onset of neurologic deficits lasting more than 24 hours
Kim
NR
with no apparent nonvascular causes
A focal or global cerebral dysfunction of presumed vascular origin lasting more than 24
hours; diagnosed by a neurologist and confirmed by a brain computed tomographic
Calafiore
a
Not performed
scan or nuclear magnetic resonance image
Aortic grading ranges from 1 to 5: 1, normal (<2 mm thickness); 2, minimal disease (2-3 mm thickness); 3, moderate disease (3-5 mm
thickness); 4, severe disease (>5mm thickness); 5, mobile plaque present in the ascending aorta; bascending aortic atherosclerotic
28
disease was defined as normal/mild (intimal thickness <3 mm), moderate (intimal thickness 3 mm to 5 mm), and severe (intimal
thickness >5 mm; or the presence of marked calcification, protruding mobile intraluminal atheromatous portions, and ulcerated
plaques)
anOPCABG, anaortic off-pump coronary artery bypass grafting; OPCABG-PC, off-pump coronary artery bypass grafting with partial
clamp; OPCABG-HS, off-pump coronary artery bypass grafting with the Heartstring system; CABG, coronary artery bypass grafting
29
Supplemental Table 3. On-pump CABG aortic cross-clamping techniques and definitions in network meta-analysis of coronary
artery bypass grafting with and without manipulation of the aorta.
Aortic cross-clamping
First author
technique
N
Definition
Calafiore
Single
2233
Cardiopulmonary bypass with aortic cannulation and crossclamping, with no side-clamping
Double
597
Cardiopulmonary bypass with aortic cannulation and crossclamping, with side-clamping
Kim
Single
76
Proximal anastomosis of free grafts was performed during a
single cross-clamp period
Lemma
Single
203
Cardiopulmonary bypass performed with single crossclamping of the ascending aorta
Patel
Double
1210
Following completion of distal anastomoses, aortic cross-
30
clamp removed and proximal anastomoses made with single
application of side-biting clamp
Kapetanakis
Double
4269
Full plus tangential (side-biting) aortic clamp application
Izumoto
NR
NR
All distal anastomoses performed with cardiopulmonary
bypass, aortic cross clamp, and cardioplegic arrest
Misfeld
NR
NR
37.0% received side-biting clamps
Emmert
NR
NR
Conventional on-pump approach with aortic cross-clamping
Moss
NR
NR
1 or 2 (cross-clamp and partial-occluding clamp) aortic clamps
were used
Single, on-pump coronary artery bypass grafting with single aortic cross-clamp; Double, on-pump coronary artery bypass grafting
with double aortic-clamping technique; NR, not reported.
31