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REVIEW ARTICLE
Hybrid Coronary Revascularization
A Review
Seshasayee Narasimhan, MD, MRCP, FRACP,* Vankeepuram S. Srinivas, MD,*
and Joseph John DeRose, Jr., MD†
Abstract: The long-term benefits of a left internal mammary artery bypass
graft compared to the left anterior descending artery have been well de-
scribed. The use of drug-eluting stents has minimized the morbidity of
revascularization. Hybrid coronary revascularization is the planned use of
minimally invasive surgical techniques for left internal mammary artery-left
anterior descending artery grafting and the use of percutaneous coronary
intervention for nonleft anterior descending coronary artery target revascu-
larization. The optimal timing and order of revascularization in hybrid
coronary revascularization remains unclear.
Key Words: hybrid coronary revascularization, robotics, minimally
invasive, coronary surgery, percutaneous coronary intervention
(Cardiology in Review 2011;19: 101–107)
Despite decades of intense scientific clinical research, contro-
versy still exists regarding the most appropriate therapy for
patients with multivessel coronary artery disease (CAD). Prospec-
tive randomized studies from each of the last 3 decades have
documented the superior long-term symptom relief and survival
benefit that coronary artery bypass grafting (CABG) affords com-
pared with both medical therapy and percutaneous coronary inter-
ventions (PCI) for multivessel CAD.
1–3
However, PCI offers a
lower level of invasiveness, a more rapid recovery, and less short-
term complications than CABG in appropriately selected patients. In
nondiabetic patients with multivessel disease and preserved left
ventricular function, PCI offers short-term survival equivalent to
CABG at the expense of an increase in repeat revascularization.
3
A
revascularization strategy that combines the durability of CABG
with the minimal invasiveness of PCI is the rationale for “hybrid”
coronary revascularization (HCR).
It is widely accepted that the survival advantage conferred
by CABG is related to the presence of a patent left internal
mammary artery (LIMA) graft sewn to the left anterior descend-
ing artery (LAD). Minimally invasive cardiac surgical techniques
have been perfected to perform this isolated LIMA-LAD revas-
cularization. Sternal-sparing incisions, the avoidance of aortic
manipulation, and the elimination of cardiopulmonary bypass
(CPB), all serve to reduce the incidence of adverse neurologic
events, bleeding, infection, and pulmonary complications com-
pared with conventional CABG.
4–8
Saphenous vein grafts have traditionally been employed as
the most commonly used conduit for non-LAD targets during
conventional CABG. However, coronary revascularization studies
employing routine postoperative angiography have demonstrated 6-
to 12-month occlusion rates of saphenous vein grafts ranging from
13% to 21%.
9–11
The clinical introduction of drug-eluting stents
(DES) has resulted in significant improvement in restenosis rates
compared with bare metal stents (BMS).
12
Although restenosis rates
have been quite low in large vessels with short uncomplicated
lesions, there has also been an improvement observed in restenosis
rates in more challenging target vessels. In a prospective study of
400 diabetic patients undergoing either sirolimus or paclitaxel DES,
6-month angiographic restenosis ranged from 8% in the paclitaxel
group to 20% in the sirolimus group.
13
In the SYNTAX trial, 226
diabetic patients with triple-vessel disease treated with multivessel
stenting with DES had a 14.2% rate of target vessel revasculariza-
tion at 12 months.
3
This equipoise in short-term patency between
DES and saphenous vein grafts to non-LAD targets provides the
fundamental basis for HCR in the treatment of multivessel CAD.
HCR, then, is defined as the planned combination of mini-
mally invasive LIMA-LAD revascularization with PCI to non-LAD
targets. This review describes the minimally invasive approaches
that exist for LAD revascularization. The different techniques for
employing HCR are also examined and future applications of HCR
are discussed.
TECHNIQUES FOR MINIMALLY INVASIVE LAD
REVASCULARIZATION
In most surgical specialties, minimally invasive surgery refers
to the access the operator takes to the surgical field. Minimally
invasive cardiac surgery, however, aims to ameliorate 2 potentially
invasive surgical components: the CPB machine and the sternotomy
incision. Therefore, surgical strategies for revascularization have
been developed which eliminate CPB, employ sternal-sparing inci-
sions, or both. These minimally invasive revascularization strategies
are primarily used for LIMA-LAD revascularization. However,
bilateral internal thoracic artery harvest can be also used to provide
more complete revascularization of the left-sided circulation.
Off-Pump CABG
Off-pump CABG is a technique of performing complete
myocardial revascularization on the beating heart through a sternot-
omy. With the development of stabilizer technology in the early
1990s, 20% to 30% of CABG surgeries are now performed in this
manner in the United States. The potential advantages of eliminating
CPB with off-pump CABG include less blood loss, lower incidence
of neurologic complications, and less pulmonary complica-
tions.
4,14–17
Although there has been concern that overall graft
patency might be lower when compared with conventional on-pump
CABG (82.6% vs. 87.8%; P⬍0.01), the patency rate for left
internal thoracic-artery pedicle grafts to the LAD was similar in the
off-pump and on-pump groups (95.3% and 96.2%, respectively; P⫽
0.48).
18
Despite the fact that off-pump CABG is primarily employed
From the *Division of Cardiology, Montefiore-Einstein Heart Center, Bronx, NY;
and †Department of Cardiovascular and Thoracic Surgery, Montefiore-
Einstein Heart Center, Bronx, NY.
Correspondence: Seshasayee Narasimhan, MD, MRCP (UK), FRACP, Depart-
ment of Medicine, Cardiovascular Division, Jack D. Weiler Hospital of the
Albert Einstein College of Medicine, 1825 Eastchester Rd, Bronx, NY
10461–2373. E-mail: docsesh@gmail.com.
Copyright © 2011 by Lippincott Williams & Wilkins
ISSN: 1061-5377/11/1903-0101
DOI: 10.1097/CRD.0b013e3182140330
Cardiology in Review • Volume 19, Number 3, May/June 2011 www.cardiologyinreview.com | 101
for complete revascularization, it can be used in selected circum-
stances as part of an HCR strategy.
Minimally Invasive Direct Coronary Artery Bypass
Grafting
Minimally invasive direct coronary artery bypass grafting
(Mid-CAB) refers to a minimally invasive LIMA-LAD revascular-
ization which is performed on the beating heart through a small
left-sided thoracotomy in the fourth or fifth interspace. Costal
cartilage removal or disarticulation is sometimes necessary and a
special chest wall retractor is used to allow for open-LIMA take-
down. Cardiac stabilization can be accomplished with a stabilizer
that is delivered directly through the wound. Mid-CAB has the
advantage of not requiring any special endoscopic or robotic skills to
master the LIMA takedown. Although single-lung ventilation im-
proves exposure, chest cavity insufflation is not necessary. However,
the degree of chest wall retraction necessary to allow for open-
LIMA mobilization is quite extensive and postoperative pain control
can be a challenge.
19
It should be noted that complete revascularization can also be
performed through a slightly larger thoracotomy. Bilateral internal
thoracic artery harvest can be accomplished in an open manner
througha5to6-cm left lateral thoracotomy and saphenous vein
grafts can be attached to the aorta as necessary to complete the
revascularization.
20–22
Large series of Mid-CAB have been reported in the literature
as early as 1994, and fairly extensive data exist from routine
angiography in these earliest series. It is clear that a comfort level
with off-pump surgery is important with this procedure and experi-
ence with sternal-sparing incisions is likewise beneficial. Short-term
patency rates with respect to left internal thoracic-artery pedicle
grafts to the LAD in both the earliest series and the more contem-
porary series range from 95% to 97%.
23–26
The advantages of
Mid-CAB over conventional CABG are rooted in the avoidance of
CPB and the absence of aortic manipulation or cross-clamping. It
appears that open Mid-CAB can decrease bleeding and infection
rates when compared with off-pump CABG ⫻1 through a sternot-
omy. However, it is not clear that there is a significant difference in
pulmonary complications or postoperative pain between open Mid-
CAB and traditional off-pump CABG ⫻1. To avoid the significant
chest wall manipulation associated with open Mid-CAB and to
improve postoperative pain control, thoracoscopic and robotic tech-
niques have been employed for LIMA mobilization which are
described later in the text.
Endoscopic Atraumatic Coronary Artery Bypass
Endoscopic atraumatic coronary artery bypass (Endo-ACAB)
refers to the thoracoscopic or robotic identification of the LAD and
complete mobilization of the LIMA without compromising the
integrity of the chest wall. A directed, nonrib-spreading or limited-
rib spreading thoracotomy then allows for a hand-sewn LIMA-LAD
anastomosis on the beating heart (Fig. 1). Robotic and thoracoscopic
techniques can also be used to mobilize both the internal thoracic
arteries. With this technique, a more complete surgical revascular-
ization can be performed.
27,28
Robotic LIMA mobilization requires single-lung ventilation
and chest cavity insufflation to develop the virtual space of the
anterior mediastinum in which the LIMA lies. Insufflation of the
chest is performed using carbon dioxide at pressures ranging from 8
to 15 mm Hg. During insufflation, a controlled pneumothorax is
induced. The resultant cardiac displacement results in rising central
venous pressure, decreased right and left heart filling, a drop in
blood pressure, and an alteration in oxygenation.
29
Adequate vol-
ume loading and peripheral vasoconstriction are necessary to main-
tain appropriate hemodynamics. After the pericardiotomy, LAD
identification, LIMA takedown, and distal transection, a small (4 –5
cm) anterior thoracotomy is performed without costal cartilage
disarticulation. The LAD is stabilized with an endoscopic stabilizer
delivered into the wound through the left arm port (Fig. 2). This
approach significantly decreases the pain and wound complications
of conventional MidCAB, yet retains the reliability of a hand-sewn
anastomosis.
Vassiliades et al have reported the largest series of thoraco-
scopic LIMA takedowns and open LIMA-LAD anastomoses
through a limited anterior thoracotomy.
6
In their series of 607
patients between 1997 and 2005, they reported a 96% LIMA-LAD
patency rate among 379 selected patients who underwent clinically
indicated cardiac catheterization. Smaller series of robotic Endo-
ACAB with routine postoperative angiography have shown similar
6- to 12-month patency rates of 95% to 99%.
30,31
Totally Endoscopic Coronary Artery Bypass Grafting
Despite the excellent results with robotic Endo-ACAB and
MidCAB, some authors have pursued the “holy grail” of totally
endoscopic coronary revascularization (TECAB). The first TECAB
surgeries were performed robotically on the arrested heart during
CPB.
32,33
Peripheral CPB with an intra-aortic balloon occluder for
cardioplegic arrest is a critical component to the arrested heart
TECAB. The complications associated with intra-aortic balloon
occlusion and the inflammatory response of CPB have led most
FIGURE 1. Robotic LIMA takedown showing anatomic rela-
tionship of LIMA, phrenic nerve, and subclavian artery at the
apex of the dissection.
FIGURE 2. Setup for the Endo-ACAB showing endoscopic
stabilizer inserted through the left arm port, and minithora-
cotomy in the fourth interspace for beating-heart, hand-
sewn anastomosis.
Narasimhan et al Cardiology in Review • Volume 19, Number 3, May/June 2011
102 | www.cardiologyinreview.com © 2011 Lippincott Williams & Wilkins
minimally invasive surgeons to opt for beating-heart off-pump
revascularization in lieu of a TECAB approach.
The beating-heart TECAB was the next extension of the
arrested heart TECAB. The beating-heart TECAB is performed in an
identical way as the robotic Endo-ACAB, with the exception of
the 4-cm thoracotomy for open, hand-sewn anastomosis. Instead, the
anastomosis is performed intracorporeally with the robot. The TECAB
has proved to be an incredibly challenging operation that only a few
have mastered. Early results are encouraging from a small number of
skilled operators, but widespread adoption of this operation had not
occurred.
34,35
Srivastava et al have the largest published series of
beating-heart TECAB patients to date. In their series of 214 patients
undergoing beating-heart TECAB from 2004 to 2007, 139 patients
underwent single-vessel bypass and 68 underwent double-vessel
bypass with an additional 7 patient receiving 3 bypass grafts. A total
of 57 grafts were studied with conventional angiography in 39
patients who had HCR. Only 1 graft failed to exhibit Fitzgibbon A
anastomosis. As a group, 3 patients required reintervention on a
surgically constructed graft at 2, 3, and 13 months for a freedom
from graft failure of 98.6%.
36
PATIENT SELECTION
Selecting patients for HCR involves close consultation be-
tween cardiac surgeon and interventional cardiologist. Surgeon and
cardiologist must address specific concerns regarding the suitability
of coronary anatomy as well as clinical characteristics as they relate
to the specifics of minimally invasive LIMA-LAD revascularization.
The angiogram should be carefully reviewed for the suitabil-
ity of the LAD for surgical grafting. A large distal LAD will provide
the best incremental advantage to LIMA-LAD revascularization as
compared with multivessel stenting. Very small LAD targets or
obvious long intramyocardial LAD segments may pose significant
technical challenges to the minimally invasive surgeon and should
be approached carefully. Total chronic occlusions of the LAD can be
safely approached with minimally invasive LIMA-LAD. However,
anterior wall viability and myocardium at risk should be assessed
preoperatively. Diffuse anterior wall thinning, or limited anterior
wall myocardial viability will limit the effectiveness of the surgical
portion of a hybrid revascularization strategy.
The non-LAD targets should be reviewed in detail for PCI
options. An estimation of both the technical considerations and the
possible long-term success of the PCI should be considered. Deci-
sions regarding the possible aggressiveness of PCI should be based
on the HCR strategy, as the presence of a patent LIMA-LAD graft
may change the safety margin for the interventional cardiologist. In
general, a suitable LAD with focal proximal lesions in the right
coronary artery and/or circumflex distribution provides the best
situations for HCR (Fig. 3).
The need for single-lung ventilation and chest cavity insuf-
flation raises important considerations when selecting patients for
minimally invasive CABG. The ideal patients will have a small
cardiac silhouette and a large left pleural space. Absolute exclusion
criteria for robotic or thoracoscopic CABG include patients with
severe chronic obstructive pulmonary disease who cannot tolerate
single-lung ventilation and those patients who have had prior left
chest surgery. Patients with severe pulmonary hypertension also
provide a relative contraindication as rapid desaturation and hemo-
dynamic compromise can occur with single-lung ventilation and
thoracic cavity insufflation. Actively ischemic patients also pose a
challenge. The chest insufflation can exacerbate ischemia and result
in malignant arrhythmias that can be challenging to handle.
Patients who are deemed poor candidates for Mid-CAB type
approaches can still have strategies designed to take advantage of an
HCR approach. In especially high-risk patients, off-pump LIMA-
LAD through a sternotomy remains an option with plans for stenting
of the non-LAD targets.
STRATEGIES FOR HCR
The first HCR procedures were reported in the mid-1990s
during the emergence of Mid-CAB and were typically performed in
staged seating with LIMA-LAD performed first.
37–40
PCI typically
had been performed with percutaneous transluminal coronary an-
gioplasty and occasional BMS. Although the early results of these
HCR procedures were excellent, concern regarding late restenosis
led many cardiologists and surgeons to reserve this procedure for
very high-risk patients.
There are 3 basic HCR approaches, all with their potential
advantages and disadvantages (Table 1): PCI can be performed first
followed by Mid-CAB; Mid-CAB can be performed first followed
by PCI; and Mid-CAB and PCI can be performed in the same sitting
in a hybrid operative suite.
PCI Then Mid-CAB
The potential advantages of a strategy that employs PCI
before Mid-CAB are 3-fold. First, revascularization of non-LAD
targets provides excellent collateral circulation, thereby minimiz-
ing the potential risk of ischemia during the LAD occlusion of
Mid-CAB. This provides a safety net of collateral flow during the
LAD occlusion at the time of Mid-CAB. Second, it allows the
interventional cardiologist the fallback position of conventional
CABG if a suboptimal PCI result be obtained. Finally, this
approach allows for HCR in the setting of acute myocardial
infarction in which the target lesion is in a non-LAD vessel. The
acute lesion can be treated and the LAD can be revascularized
with a Mid-CAB at a later sitting.
Although this approach was used fairly commonly in the era
of percutaneous transluminal coronary angioplasty and BMS, the
risk of acute stent thrombosis with DES has raised serious concern
about such an approach. With this strategy, in-hospital patients need
to be maintained on eptifibatide (Integrilin; Schering Plough, Ken-
ilworth, NJ), which can be stopped for the Mid-CAB. Clopidogrel
(Plavix; Bristol Myers Squibb, Bridgewater, NJ) can be adminis-
tered once the patient is extubated in the postoperative period.
However, it is clear that the risk of stent thrombosis with both BMS
within 1 month and DES for up to 1 year is related to both brief
discontinuation of glycoprotein IIIa/IIb inhibitors and the inflamma-
tory reaction of both noncardiac and cardiac surgery.
41
Some sur-
geons have performed the Mid-CAB on clopidogrel, but this ap-
proach is plagued by an increased incidence of bleeding (9.6% vs.
FIGURE 3. Completed LIMA-LAD anastomosis with endo-
scopic stabilizer still in place.
Cardiology in Review • Volume 19, Number 3, May/June 2011 Hybrid Coronary Revascularization
© 2011 Lippincott Williams & Wilkins www.cardiologyinreview.com | 103
7.5%).
42
Furthermore, such an approach does not eliminate the risk
of stent thrombosis in the setting of inflammatory mediator release
from the trauma of surgery.
This approach can still be used in selected situations. It should
be kept in mind, especially in the setting of BMS placement for
acute myocardial infarction. Brief discontinuation of Plavix after 1
month of therapy, or surgery on Plavix remain viable options in
these patients at the time of their Mid-CAB.
Mid-CAB Then PCI
With the broad application of DES, this strategy has become
the most widely adopted for HCR. The primary advantage of this
approach is that aggressive antiplatelet therapy can be initiated early
after surgery and continued for long-term, as is recommended for
maximum patency after implantation of DES. A second advantage is
that the integrity of the LIMA-LAD can be confirmed through
angiography at the time of PCI completion. Finally, this approach
FIGURE 4. A, Preoperative angiogram
of a patient for staged-hybrid revascu-
larization demonstrating high-grade
proximal LAD lesion. B, Right anterior
oblique projection demonstrating
proximal and mid circumflex lesion.
C, Angiogram on postoperative day 3
of patent LIMA-LAD anastomosis at
the time of staged-hybrid revascular-
ization. D, Completion angiogram
after DES placement to circumflex and
successful hybrid revascularization.
TABLE 1. Advantages and Disadvantages of 3 Different HCR Strategies
HCR Strategy Advantages Disadvantages
PCI followed by Mid-CAB 1. Minimize risk of ischemia during Mid-CAB
2. Conventional CABG as fallback if suboptimal PCI result
3. HCR is possible in the setting of PCI for myocardial
infarction in non-LAD targets
1. Risk of stent thrombosis with discontinuation of
antiplatelet inhibitors and inflammation of
Mid-CAB
2. Increased bleeding if Mid-CAB performed on dual
antiplatelet therapy
3. Cannot routinely image LIMA-LAD
Mid-CAB followed by PCI 1. Aggressive continuous antiplatelet therapy following PCI
2. Routine angiography of LIMA-LAD
3. PCI of high-risk lesions is possible with a patent
LIMA-LAD
1. Mid-CAB is performed in the setting of residual
coronary lesions
2. Fallback conventional CABG leads to higher
morbidity if suboptimal PCI result
Simultaneous Mid-CAB and PCI 1. Immediate angiography of LIMA-LAD
2. Aggressive PCI of high-risk lesions with a documented
patent LIMA-LAD
3. Complete revascularization out of operating room
1. Bleeding risk with dual antiplatelet therapy at the
time of surgery
2. Risk of stent thrombosis in setting of inflammatory
response of surgery
3. Economic and logistic issues
Adapted from Semin Thorac Cardiovasc Surg. 2009;21:229 –236.
Mid-CAB indicates minimally invasive coronary artery bypass graft; PCI, percutaneous coronary intervention; HCR, hybrid coronary revascularization; LIMA-LAD, left internal
mammary artery-left anterior descending artery; CABG, coronary artery bypass grafting.
Narasimhan et al Cardiology in Review • Volume 19, Number 3, May/June 2011
104 | www.cardiologyinreview.com © 2011 Lippincott Williams & Wilkins
TABLE 2. Hybrid Coronary Revascularization Series
Author Institution Date n Mid-CAB PCI HCR Strategy F/U
30-d
Mortality
(%)
LIMA
Patency
(%) TVR
Event-
Free
Survival
Zenati et al
37
Pittsburgh 1999 31 Open Mid-CAB BMS 66% PTCA
34%
PCI then Mid-CAB 7%
Same day 52%
Mid-CAB then PCI 9%
10.8 mo 0 100 9.6 90
Lloyd et al
40
Bristol Heart 1999 18 Open Mid-CAB PTCA 52%
BMS 48%
Mid-CAB then PCI 77%
Simultaneous 23%
6 mo 0 100 0 100
Wittwer et al
44
Hannover 2000 35 Open Mid-CAB PTCA 70%
BMS 30%
Mid-CAB then PCI 11.5 d 0 100 NA NA
Riess et al
45
Hamburg 2002 57 Lower Hemisternotomy PTCA 58%
BMS 42%
Mid-CAB then PCI 24 mo 0 97 16 NA
Stahl et al
46
Multi-USA 2002 54 Robotic Endo-ACAB PTCA PCI then Mid-CAB 35%
Mid-CAB then PCI 65%
11.7 mo 0 100 NA 87
Cisowski et al
47
Poland 2002 50 Thoracoscopic Mid-CAB PTCA 22%
BMS 78%
Mid-CAB then PCI 6–24 mo 0 100 13 87
Davidavicius
et al
31
Belgium 2005 20 Robotic Endo-ACAB BMS 95% DES 5% PCI then Mid-CAB 70%
Mid-CAB then PCI 30%
19 mo 0 100 0 100
Katz et al
48
Multi-
International
2006 27 Arrested heart TECAB BMS 37% DES 63% PCI then Mid-CAB 41%
Mid-CAB then PCI 44%
Simultaneous 15%
9 mo 0 100 29.6 70
Vassiliades et al
49
Emory 2006 47 Thoracoscopic Endo-ACAB DES PCI then Mid-CAB 11%
Mid-CAB then PCI 89%
7 mo 0 100 8.5 89
Gilard et al
50
France 2007 70 Conventional On-pump
CABG
Stent to RCA CABG then PCI 33 mo 1.4 100 NA 96
Kon et al
5
Maryland 2008 15 Open Mid-CAB DES Simultaneous 12 mo 0 100 6.7 93
Kiaii et al
39
Western Ontario
Canada
2008 58 Robotic Endo-ACAB DES 90%
BMS 10%
Simultaneous 20 mo 0 93 10.3 NA
Holzhey et al
51
Germany 2008 117 Mid-CAB 107, Beating-
heart TECAB 8, Arrested
heart TECAB 2
BMS, DES 4–6 wk preoperative (53),
2–45 d postoperative
(59), Intraoperative (5)
1–5 yr, 208
patient-
years
1.9% NA 2.5% 85.5% at
1yr
Zhao et al
43
Tennessee 2009 75.5% at
5yr
Gao et al
38
China 2009 10 Robotic Mid-CAB 6
Beating-heart TECAB 4
BMS 67%
DES 23%
Mid-CAB, then PCI 5 mo 0 100 NA NA
Adapted from Semin Thorac Cardiovasc Surg. 2009;21:229 –236.
BMS indicates bare metal stent; DES, drug-eluting stent; Endo-ACAB, endoscopic atraumatic coronary artery bypass; HCR, hybrid coronary revascularization; LIMA, left internal mammary artery; Mid-CAB, minimally
invasive direct coronary artery bypass; PCI, percutaneous coronary intervention; PTCA, percutaneous transluminal coronary angioplasty; RCA, right coronary artery; TECAB, totally endoscopic coronary artery bypass; TVR, target
vessel revascularization; CABG, coronary artery bypass grafting.
Cardiology in Review • Volume 19, Number 3, May/June 2011 Hybrid Coronary Revascularization
© 2011 Lippincott Williams & Wilkins www.cardiologyinreview.com | 105
gives the interventional cardiologist the ability to approach lesions
that otherwise would be quite hazardous if the LAD has not been
protected. Left main lesions and diagonal bifurcation lesions are just
2 such lesions that can be more safely treated through PCI with a
protected LAD.
The minimally invasive surgeon should be cognizant of
possible intraoperative ischemia with this HCR approach because
the collateral, non-LAD vessels are unrevascularized. Judicious use
of intracoronary shunts, careful attention to cardiac-filling pressures
and systemic blood pressure during insufflation, and the use of
peripheral CPB when necessary are all critical to success in this
setting. This HCR approach also makes the determination para-
mount that PCI has a very high chance of success and a low chance
of procedural complications with the non-LAD lesions assigned for
treatment. (Fig. 4).
It remains unclear at present what is the optimal timing for
PCI following Mid-CAB. A period of waiting after surgery seems
prudent to allow the patient to resolve the potential inflammatory
milieu which exists immediately after the operation. This response is
quite brief and usually has resolved within 3 to 5 days, making it
possible to perform PCI on the index hospitalization or days to
weeks later. Patients may need 7 to 10 days of mental and physical
recovery before undergoing a second procedure. However, some
physicians may feel uneasy discharging certain patients with an
incomplete revascularization, prompting PCI before discharge. Eco-
nomic issues also bear on the hospital system, as a single diagnosis-
related group is typically used to reimburse 2 separate costly
procedures. As HCR becomes more common, these issues will
likely be addressed to provide a fuller hospital reimbursement.
Simultaneous Mid-CAB and PCI
With the advent of endovascular surgical procedures and
percutaneous valvular therapy, operating suites have been created
that have the capability of both minimally invasive surgical proce-
dures and PCI. This has led some investigators to favor a combined
Mid-CAB with completion angiography and stenting of non-LAD
vessels in the same operative sitting.
5,37
The potential advantages of
such an approach include the ability to perform routine imaging of
the LIMA-LAD before closure to confirm an anatomically accept-
able anastamosis. Complete revascularization before leaving the
operating suite is the other major advantage of such an approach.
The emotional and psychologic benefit to the patient of a complete
“fix” in 1 anesthetic sitting also has its merits. Finally, PCI per-
formed in the setting of a completed LIMA-LAD allows a more
aggressive percutaneous approach to otherwise challenging lesions.
The security of general anesthesia and the operating room likewise
provide a safety net if a PCI failure occur.
Zhao et al have recently published the importance of control
angiography following both conventional and Mid-CAB. They per-
formed routine completion angiography on 336 patients undergoing
conventional open-chest CABG. Among 796 grafts studied, 97
grafts (12%) showed significant defects. Defects were repaired with
either a minor adjustment of the graft (n ⫽22, 2.8%), with
intraoperative open-chest PCI (unplanned hybrid, n ⫽48, 6%) or
with traditional surgical revision (n ⫽27, 3.4%).
43
Detractors of the simultaneous HCR point to increased oper-
ative time, increased cost, and inadequate hospital reimbursement.
Bleeding also becomes a concern because full antiplatelet therapy
and incomplete heparin reversal are necessary immediately after
Mid-CAB to maximize successful intraoperative DES placement.
Although the inflammatory response of Mid-CAB is blunted com-
pared with conventional off-pump CABG, some interventionalists
have raised concern about immediate intraoperative DES placement
and acute stent thrombosis.
35
In summary, of the 3 general strategies for HCR, not enough
data exist to support one approach over another. All 3 approaches
have their merits and disadvantages, which need to be weighed and
applied in each clinical scenario for each individual patient.
RESULTS OF HCR
Over the last decade, approximately 500 patients undergoing
HCR have been reported in the literature (Table 2).
5,31,37–40,43–51
The variable surgical approaches, HCR techniques, and the percent-
age of DES placement make global conclusions difficult. However,
routine angiography in most studies does demonstrate that patency
of minimally invasive LIMA-LAD by all previously described
methods compares favorably with conventional CABG. Target ves-
sel revascularization appears to vary based on the number of stents
placed and the percentage of DES used in each study. Reintervention
of LIMA-LAD in all studies varies from 1% to 3%, again giving
support to this procedure as an equivalent revascularization strategy
to conventional CABG in experienced hands.
CONCLUSIONS
Mid-CAB has generated a breadth of data that allow it to be
considered one of the standard revascularization strategies available
to patients with CAD. As the population of patients with CAD grows
older, with increasing comorbidities, unique approaches to revascu-
larization will need to be designed for each patient. In the patient
with multivessel disease, conventional CABG on CPB, off-pump
CABG, multivessel stenting, and HCR should all be considered.
After evaluating both coronary anatomy and the unique medical
conditions of each individual patient, the caregiver should decide
which approach will either improve the quality of life or prolong the
life expectancy of their patients.
The comparative effectiveness of HCR to both conventional
CABG and multivessel stenting is an important question that awaits
clinical studies. An ongoing National Institutes of Health observa-
tional planning study of hybrid revascularization and multivessel
stenting will serve to design a pivotal trial comparing these 2
techniques in the treatment of multivessel CAD.
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