1) The document describes the use of off-pump coronary artery bypass grafting (OPCAB) and hybrid procedures combining OPCAB and angioplasty to perform minimally invasive coronary revascularization without cardiopulmonary bypass. 2) Of 216 patients who underwent OPCAB, the procedure was successful in achieving technically complete revascularization in 84% of patients with multivessel disease, either through multivessel OPCAB or a hybrid approach. 3) Postoperative outcomes were good with a low mortality rate of 1.4% and few complications. Graft patency rates improved to over 93% with the use of heart stabilizers during surgery. The hybrid procedures were effective but carried a risk

1. Minimally Invasive Coronary Artery
Revascularization: Off-Pump Bypass Grafting
and the Hybrid Procedure
Tadashi Isomura, MD, Hisayoshi Suma, MD, Taiko Horii, MD, Toru Sato, MD,
Teisei Kobashi, MD, and Hideo Kanemitsu, MD
Cardiovascular Surgery, Shonan Kamakura General Hospital, Kamakura, Kanagawa, Japan
Background. Coronary artery bypass grafting without
cardiopulmonary bypass (off-pump-CAB; OPCAB) as a
minimally invasive procedure has been used increas-
ingly to treat coronary artery disease. The procedure
makes multivessel revascularization possible, with new
instruments and techniques, and hybrid therapy (com-
bination of angioplasty and OPCAB) can be a new
method of treating coronary disease. We present our
experience using OPCAB and our strategy for coronary
revascularization.
Methods. Of 216 patients treated with OPCAB, the
lesion was single in 100 and multivessel in 116. Preoper-
ative risks that could increase the mortality and morbid-
ity rates were present in 127 patients, excluding 55 who
were 75 years old or older.
Results. There were four hospital deaths, three of
which were noncardiac, and five operative morbidities:
transient cerebral ischemia in 3, perioperative myocardial
infarction in 1, and congestive heart failure in 1. A
postoperative angiogram was done in 157 patients (220
grafts), and with heart stabilization the patency rate
without stenosis improved to 93.6%. For 116 patients
with multivessel disease, technically complete revascu-
larization was done in 84%, either with multivessel
revascularization in 61 patients or the hybrid procedure
in 37 patients. Among 20 patients with left main trunk
lesion, five had the hybrid procedure. Angina recurred in
3, including 1 who died suddenly of infarction. The
angiogram at recurrence showed restenosis of left main
lesion and occlusion of the graft to the left anterior
descending artery. Postoperative follow-up for 2 years
showed 12 patients with recurrent angina and five late
deaths from noncardiac-related events.
Conclusions. The heart stabilizer and new techniques
for coronary revascularization with a beating heart have
improved the anastomotic quality of grafts. The hybrid
procedures were effective in selected patients but were
considered contraindicated in patients with left main
trunk lesion. OPCAB was safe, effective, and suitable
especially in patients with high risks for coronary artery
bypass grafting.
(Ann Thorac Surg 2000;70:2017–22)
© 2000 by The Society of Thoracic Surgeons
Since Benetti and Ballester [1] reported coronary artery
bypass grafting (CABG) through a left anterior small
thoracotomy (LAST) without cardiopulmonary bypass
(CPB) in 1994, CABG without sternotomy and CABG with
no CPB have gained worldwide interest.
With the increase of CABG without CPB (off-pump
CABG, OPCAB), new operative instruments have been
developed. The heart stabilizer has improved the quality of
anastomosis with a beating heart. We have been perform-
ing the LAST operation since 1996 and simultaneously
performing OPCAB through a median sternotomy to
complete multiple coronary artery revascularization.
Patients and Methods
Between January 1996 and December 1999, 216 patients
had CABG without CPB. There were 155 men and 61
women, and their ages ranged from 27 to 89 years (mean,
68 years). Preoperative angiogram showed single-vessel
coronary artery disease in 100 patients and multivessel
coronary artery disease in 116 patients, including 20
patients with a left main trunk (LMT) lesion (Table 1).
Preoperative risks were seen in 127 patients (58.8%),
excluding 55 patients (25.4%) who were 75 years old or
older, and are given in Table 2. In 57 patients CPB was
considered to be impossible or high risk because of
calcified ascending aorta, bleeding tendency, severe ce-
rebrovascular lesion, or a combination of those lesions. In
the other 70 patients CPB was avoided because of in-
creased operative morbidity from the effect of CPB on
risks such as severe peripheral vascular lesion, renal
failure, cancer, or chronic obstructive pulmonary disease
(Table 2). The LAST operation was done in 87 patients,
and median sternotomy was done in 121 patients, exclud-
ing three subxyphoid and five lower half-sternotomy.
The patients with multivessel lesions including LAD
lesion for CABG and who were free of calcification or
chronic total occlusion in the other coronary arteries by
Accepted for publication April 27, 2000.
Address reprints requests to Dr Isomura, Cardiovascular Surgery,
Hayama Heart Center, 1898 Shimoyamaguchi, Hayama, Kanagawa, Japan
240-0116; e-mail: isomura@hayamaheart.gr.jp.
© 2000 by The Society of Thoracic Surgeons 0003-4975/00/$20.00
Published by Elsevier Science Inc PII S0003-4975(00)01839-7

2. angiographic assessment were considered candidates for
hybrid therapy.
Selection of Patients
LEFT ANTERIOR SMALL THORACOTOMY OPERATION. The patients
who had failure of angioplasty or stenting and isolated
left anterior descending (LAD) coronary artery disease
were selected as candidates for small thoracotomy. The
patients with reoperation, LAD lesion, and suitable an-
gioplasty for concomitant coronary disease were also
candidates for this procedure. Chronic obstructive pul-
monary disease was a contraindication for this approach
because of lung decompression during this procedure.
MEDIAN STERNOTOMY AND OFF-PUMP CORONARY ARTERY BYPASS.
Patients who required multiple CABG and had preoper-
ative risks that contraindicated CPB were considered
candidates for complete multivessel revascularization or
OPCAB plus percutaneous transluminal coronary angio-
plasty (PTCA) (hybrid therapy).
COMBINED OFF-PUMP CORONARY ARTERY BYPASS AND ANGIO-
PLASTY. Angioplasty was done in the diseased vessels
other than the LAD artery. If vessels were totally oc-
cluded, tortuous, or an extensive lesion was present,
angioplasty was contraindicated.
Surgical Technique
In LAST operations, a left submammary incision measur-
ing 7 cm was made, and the chest was entered through
the forth or fifth intercostal space. The left internal
thoracic artery (LITA) was harvested between the second
or first intercostal space and the fifth intercostal space
under direct vision or by using a retractor (LIMA Lift;
Cardio Thoracic System, Cupertino, CA). After 100 IU/kg
of heparin was given and activating coagulation time was
controlled at 250 to 300 seconds, the ITA was divided
distally. After the LAD was exposed, the proximal and
distal LAD was snared with elastic suture (Matsuda Ika
Kogyo, Tokyo, Japan), and the anastomosis was con-
structed with continuous 7.5 Oval-M monofilament (Mat-
suda Ika Kogyo, Tokyo, Japan) using the double-
parachute method. Coronary artery stabilization was
obtained not pharmacologically but mechanically (Plat-
form Access, Cardio Thoracic System, or Matsuda Ika),
and a bloodless field was obtained with a carbon dioxide
blower.
Median sternotomy was used in most patients who
required multivessel OPCAB. After the full sternotomy,
the LITA was mobilized from the sixth rib to the subcla-
vian vessels in the usual fashion. After takedown of the
LITA, the LITA-LAD anastomosis was completed as done
in the LAST operation. To accomplish the revasculariza-
tion of an obtuse marginal branch or posterodescending
artery, two 1-cm stockinet gauzes (Heart holder tapes;
Matsuda Ika Kogyo, Tokyo, Japan) were passed through
the transverse sinus and behind the inferior vena cava,
and the heart was rotated to a proper position by lifting
the tapes with the patient in the Trendelenburg position.
After exposure and stabilization, the obtuse marginal or
posterodescending branch was revascularized with ei-
ther saphenous vein or gastroepiploic artery. The hemo-
stasis was secured and the incision was closed. Postop-
erative electrocardiogram, serum creatine kinase, and
creatine kinase-MB levels were measured routinely in
the intensive care unit. Postoperative angiogram was
taken on the same postoperative day or 1 day before
discharge within 1 week postoperatively in most patients
to confirm the quality of anastomosis. In patients who
received hybrid therapy, the PTCA or stenting was done
simultaneously with the postoperative angiogram.
All patients were followed up postoperatively, and the
longest follow-up time was 30 months. Recurrence of
angina, myocardial infarction, repeated PTCA, redo sur-
gery, or cardiac death was considered a cardiac-related
event, and both cardiac and noncardiac deaths were
surveyed.
Results
In LAST operations, single bypass of LITA to LAD was
done in most patients. The number of distal anastomoses
in patients with median sternotomy ranged from one to
four, and the mean number was 1.6 per patient. Conver-
sion to CPB did not occur, but conversion from the LAST
operation to median sternotomy occurred in 3 patients, 2
Table 1. Preoperative Characteristics of 216 Patients Who
Had Off-Pump Coronary Artery Bypass Grafting
Age (y) 68 (27–89)
Female 61 (28%)
Coronary lesion
Single 100
Multivessel 116
Double 62
Triple 34
Left main 20
Table 2. Preoperative Risks in Patients
Preoperative Condition No. of Patients
Cerebrovascular lesion 36
Calcified aorta 23
Bleeding tendency 8
Subtotal 57a
Renal failure/HD 29
Previous CABG 16
Malignancy 17
ASO 1
COPD 11
Total 127b
Age Ͼ 75 55)
a
There were 67 lesions in 57 patients. b
There were 141 lesions in 127
patients.
ASO ϭ atherosclerosis obliterance; CABG ϭ coronary artery bypass
grafting; COPD ϭ chronic obstructive pulmonary disease; HD ϭ
hemodialysis.
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OFF-PUMP BYPASS AND HYBRID PROCEDURE 2000;70:2017–22

3. because the LAD was deeply intramuscular and 1 be-
cause of failure of the exposure of the LITA. The LITA
was injured during harvest through a left thoracotomy in
5 patients, and the inferior epigastric artery was anasto-
mosed to the proximal LITA to repair the graft. All
injuries occurred at the fourth or fifth intercostal space at
the beginning of the harvest through a left thoracotomy.
Ventricular fibrillation occurred in 1 patient when the
heart was lifted and rotated to expose the marginal
artery; electric shock was required.
Early death (within 30 days postoperatively) occurred
in 3 patients (1.4%). In 2 of them ischemic intestinal
necrosis developed 1 or 6 days postoperatively. One
82-year-old died of LMT lesion dissection resulting from
PTCA trouble and emergent off-pump CABG of LITA to
LAD. One patient died of perioperative cerebral infarc-
tion in the hospital more than 30 days after operation; the
patient had cerebral infarction and renal failure at the
time of preoperative coronary angiogram. After stabili-
zation of the neurologic symptoms, OPCAB was done.
During the operation systemic pressure was maintained at
100 to 120 mm Hg; however, the permanent stroke occurred
postoperatively and multiorgan failure developed.
In the intensive care unit, transient cerebral ischemia
occurred in 3 patients with severe cerebrovascular dis-
ease; however, all of them recovered without permanent
neurologic symptoms. Perioperative myocardial infarc-
tion occurred in 1 patient 4 hours postoperatively, and
emergent angiogram showed LAD thrombosis; PTCA
and thrombolysis were successful. Congestive heart fail-
ure developed in 1 patient after the operation, and the
angiogram showed residual severe mitral regurgitation
and incorrect anastomosis of the LITA, not to the LAD
but to the diagonal branch. The patient had a successful
redo operation for mitral repair and revascularization of
LAD with the use of CPB and median sternotomy 14 days
after the initial LAST operation. No patient had ventric-
ular tachycardia in the intensive care unit.
Postoperative angiograms were done for 220 grafts (157
patients) (Fig 1). Early in this series, no stabilization was
used, and the graft patency was 83.7%, excluding 12.5% of
stenosis of the anastomotic site. After the use of heart
stabilization, the patency rate without stenosis improved
to 93.6%. The ITA was used in 193 grafts, the saphenous
vein in 54, gastroepiploic artery in 23, and radial artery in
seven (Table 3). The inferior epigastric artery was used to
repair the injured ITA or extension of the arterial graft.
For redo CABG, the proximal site of the free radial artery
or saphenous vein was anastomosed to the left subcla-
vian artery (Fig 2) in 6 patients to avoid reentry of the
median sternotomy and to enter through a left
thoracotomy.
In 116 patients with multivessel disease, hybrid ther-
apy (OPCAB and PTCA) was done in 37 patients, and 40
vessels were treated at the time of postoperative angio-
gram. Technically complete revascularization for the
multivessel lesions was done in 57 patients, excluding
transmyocardial laser revascularization in 4 patients with
small target vessels (Table 4). In 5 patients with LMT
lesion, hybrid therapy was done during our early series.
Angioplasty to the LMT lesion was successful within 7
days after a LAST operation of LITA to LAD; however,
angina recurred in 3 patients within 3 months after
treatment, including one death from acute myocardial
infarction. Those patients had restenosis of the LMT
lesion in addition to occlusion of the LITA to LAD or
string of the LITA graft that had been fully patent at the
time of the first early postoperative angiogram (Fig 3).
The remaining 18 patients who did not receive complete
OPCAB or hybrid procedures had single revasculariza-
tion of the LAD. Nine of them had calcified aorta or
preoperative severe cerebrovascular lesion. Four patients
had no operative risks and they had double-vessel le-
sions, LAD lesion and lesions in small right coronary
artery, or circumflex artery. One patient had redo CABG
and 2 required repeat PTCA after discharge because of
angina. There were no late deaths among those 18
patients.
All 212 operative survivors were followed up, and 5
patients died after discharge. Causes of death included
noncardiac events such as cerebrovascular disease, liver
disease, and cancer. Twelve patients had recurrent an-
gina, including 3 with LMT lesion. All 12 patients had a
repeat angiogram; the LITA had become stenotic or
occluded in 4 patients, and the lesion of the nonbypassed
vessel was treated by angioplasty or medication. The
longest survival in this series was 30 months, and 207
patients currently survive, with 90.1% of them without
angina.
Comment
In 1967 Kolessov [2] reported CABG without CPB; how-
ever, the use of CPB has been the gold standard for
Fig 1. Off-pump coronary artery bypass grafting with the use of a
heart stabilizer in a 56-year-old patient with cerebrovascular dis-
ease. The left internal thoracic artery (LITA) was anastomosed to
the left anterior descending artery (LAD) and the right gastroepip-
loic artery (GEA) to the posterodescending branch (PD). Postopera-
tive angiograms were taken on the sixth postoperative day, and in
both grafts, flow completely filled the coronary arteries.
2019Ann Thorac Surg ISOMURA ET AL
2000;70:2017–22 OFF-PUMP BYPASS AND HYBRID PROCEDURE

4. complete revascularization for CABG. After some chal-
lenging reports [1, 3, 4] of CABG through a small left
thoracotomy (LAST operation) or lower-half sternotomy
[5] without pump, CABG without CPB became increas-
ingly popular as an alternative to CABG. Since 1996, we
have been using the LAST operation and have been
interested in OPCAB through both left thoracotomy and
median sternotomy. In this study, we presented opera-
tive results of OPCAB and the hybrid procedure. The
main reason for the LAST operation was patient driven;
it enables faster recovery and an earlier return to work
because it does not require sternotomy, although the
surgical benefit was obtained by this technique in redo
CABG. In contrast, the OPCAB through a median ster-
notomy was surgically driven in most patients, to de-
crease surgical morbidity after use of CPB. In our series,
58.8% of the patients had preoperative risks for CABG.
The hospital mortality rate was 1.9%, including 1.4% from
noncardiac deaths. Despite a high-risk patient group,
other operative morbidity with OPCAB was low [6]. The
disadvantages of OPCAB were difficulty of LITA mobili-
zation through thoracotomy that used an unfamiliar
approach and performing anastomotic stenosis or graft
occlusion procedures with a beating heart. Many instru-
ments were different from those used in conventional
CABG, such as LITA harvesting kits and several kinds of
heart stabilizers [6, 7]. When we compared our early graft
patency results without heart stabilizer to those with
stabilizer by postoperative angiogram, the patency rate
Fig 2. For a patient with redo coronary artery bypass grafting and
requiring single left anterior descending artery (LAD) revasculariza-
tion, the left subclavian artery, which was rarely sclerotic, was se-
lected as the site of proximal anastomosis. The left radial artery
(RA) was anastomosed to the left subclavian artery proximally and
LAD distally in a 63-year-old patient who had previous coronary
artery bypass grafting and occluded left internal thoracic artery-to-
LAD graft. With the LAST procedure, operative morbidity was low
because adhesion was minimal.
Table 3. Number of Distal Anastomoses, Type of Graft, and
Early Patency Rate by Postoperative Angiogram
Mean (range) distal anastomosis 1.4 (1–4)
Conduit
ITA 193 (Left 178, Right 15)
GEA 22 (ϩITA, 2)
RA 7 (ϩITA, 2)
IEA 16 (ϩITA, 15; ϩRA, 1)
SV 54 (ϩITA, 1)
Patency
Without stabilizer (n ϭ 48)
Patent 40 (83.7%)
Stenosed 6 (12.5%)
Occluded 2 (4.2%)
With stabilizer (n ϭ 172)
Patent 161 (93.6%)
Stenosed 5 (2.9%)
Occluded 6 (3.5%)
GEA ϭ gastroepiploic artery; IEA ϭ inferior epigastric artery; ITA
ϭ internal thoracic artery; RA ϭ radial artery; SV ϭ saphenous
vein.
Table 4. Multivessel Lesion and Therapeutic Method in 116
Patients Who Had Off-Pump Angioplasty-Bypass
Combination Therapy
Site of Angioplasty No. of Patients
RCA 20
CX 13
LAD, Diag 2
LMT 5
Total 37a
Complete revascularization (n ϭ 57)b
Grafted coronary system
LAD 57
Diag 5
PD 46
OM 23
TMR 4
a
There were 40 angioplasties in 37 patients. b
Complete revascular-
ization was done in 84% of multivessel lesions, with 32% being hybrid
procedures and 52% complete CABG.
CABG ϭ coronary artery bypass grafting; CX ϭ circumflex; Diag
ϭ diagonal branch; LAD ϭ left anterior descending branch; LMT
ϭ left main trunk; OM ϭ obtuse marginal branch; PD ϭ posterior-
descending branch; RCA ϭ right coronary artery; TMR ϭ
transmyocardial laser revascularization.
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OFF-PUMP BYPASS AND HYBRID PROCEDURE 2000;70:2017–22

5. improved from 83.7% to 93.6%. For harvesting LITA,
careful attention was required while opening the fourth
or fifth intracostal space. However, when we used full or
lower-half median sternotomy the procedure of LITA
dissection was similar to that routinely used. The second
disadvantage of the LAST procedure was that the tech-
nique did not allow complete revascularization through a
left thoracotomy. To solve this problem, we combined the
LAST operation with PTCA as the hybrid procedure
reported by others [8–10]. The candidates for the hybrid
procedure were limited by the suitability of lesions for
PTCA; they were carefully followed up for restenosis
after the angioplasty. Therefore, selection of candidates
was very important for this procedure. In our series, the
hybrid procedure was used in 32% of the patients with
multivessel lesions. Among them, this procedure was
attempted in 5 with LMT lesion to minimize the invasive-
ness of the treatment. The PTCA to treat the LMT lesion
Fig 3. The left main trunk (LMT) lesion was treated by hybrid procedures in 5 patients. The anastomosis of the left internal thoracic artery
(LITA) to the left anterior descending artery (LAD) was patent in the early postoperative period (A) and the LMT lesion was treated success-
fully with angioplasty simultaneously (B). However, angina recurred 3 months after the procedures, and angiogram showed occluded left LITA
graft and restenosis of the LMT lesion (A, B). The LMT lesion is now considered a contraindication for hybrid therapy. (p/OP ϭ postopera-
tive; PTCA ϭ percutaneous transluminal coronary angioplasty.)
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2000;70:2017–22 OFF-PUMP BYPASS AND HYBRID PROCEDURE

6. after the LAD revascularization with LAST was success-
ful in all 5 patients; however, angina recurred in 3
patients, including 1 who had acute myocardial infarction
and cardiac death because of restenosis of the LMT lesion
and LITA failure from incompetent flow of the LAD after
treatment of the LMT lesion. Although Liekweg and
Misra [11] reported a case of successful treatment of LMT
lesion with the hybrid procedure, we believe that the
hybrid procedure for LMT lesion is not ideal because of
sudden onset of LMT restenosis and LITA collapse. The
increased interest in OPCAB has resulted in complete
revascularization without CPB by applying several tech-
niques and instruments, such as rotation of the table,
lifting the heart to facilitate marginal or inferior wall
grafting, pericardial mobilization, and local heart-
stabilization instruments. The multivessel CABG was
performed by median sternotomy and results were sim-
ilar to or better than those obtained by ordinary CABG
with CPB. In our series, most patients who had median
sternotomy had preoperative risks for surgery; however,
mortality and morbidity rates were low and the results
were good at 2 years of follow-up.
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OFF-PUMP BYPASS AND HYBRID PROCEDURE 2000;70:2017–22