Surgical Treatment for Thoracic Aneurysms: Comparison of Stent Grafting and Open Surgery

Abstract

Objectives:
Early and mid-term results of stent graft (SG) treatment for thoracic aortic aneurysms (thoracic endovascular aneurysm repair: TEVAR) were retrospectively compared with open surgical treatment.

Methods:
The records of 213 patients in whom single thoracic aortic aneurysm repairs had been performed in our department from January 2006 through August 31, 2009 were reviewed. Acute aortic dissection was excluded. Each case was reviewed for indications for TEVAR from an anatomical standpoint. Among 62 cases in which TEVAR was indicated, 30 (SG group) were treated by TEVAR and 32, by open surgery (OP group). Early and mid-term results were analyzed retrospectively in both groups.

Results:
There were no operative deaths in either group. The SG group demonstrated significantly less operative bleeding, a shorter operative time, and shorter postoperative hospital stay compared with the OP group. There were 3 deaths in the SG group and 4 in the OP group, which occurred within an average of 656.4 days during the follow up period. The 3 year actuarial survival rate was 88.7% in the SG group and 87.1% in the OP group, and there were no significant differences between the groups.

Conclusion:
Although early and mid-term results of TEVAR and open surgery were similar, TEVAR is generally less invasive and may be preferable for high-risk patients, compared with open surgical repair. (English Translation of Jpn J Vasc Surg 2010; 19: 51-56.).

Full text

15
Annals of Vascular Diseases Vol.5, No.1 (2012)
Original Article
Surgical Treatment for Thoracic Aneurysms:
Comparison of Stent Grafting and Open Surgery
Koichi Yuri, MD, Atsushi Yamaguchi, MD, PhD, Daijiro Hori, MD, Manabu Shiraishi, MD,
Hiroshi Nagano, MD, Atsushi Tamura, MD, Kenichiro Noguchi, MD, Kazuhiro Naito, MD,
Kazunari Nemoto, MD, and Hideo Adachi, MD, PhD
Objectives: Early and mid-term results of stent graft (SG) treatment for thoracic aortic aneurysms (thoracic
endovascular aneurysm repair: TEVAR) were retrospectively compared with open surgical treatment.
Methods: The records of 213 patients in whom single thoracic aortic aneurysm repairs had been performed
in our department from January 2006 through August 31, 2009 were reviewed. Acute aortic dissection
was excluded. Each case was reviewed for indications for TEVAR from an anatomical standpoint. Among
62 cases in which TEVAR was indicated, 30 (SG group) were treated by TEVAR and 32, by open surgery
(OP group). Early and mid-term results were analyzed retrospectively in both groups.
Results: There were no operative deaths in either group. The SG group demonstrated signicantly less
operative bleeding, a shorter operative time, and shorter postoperative hospital stay compared with the
OP group. There were 3 deaths in the SG group and 4 in the OP group, which occurred within an average
of 656.4 days during the follow up period. The 3 year actuarial survival rate was 88.7% in the SG group
and 87.1% in the OP group, and there were no signicant differences between the groups.
Conclusion: Although early and mid-term results of TEVAR and open surgery were similar, TEVAR is
generally less invasive and may be preferable for high-risk patients, compared with open surgical repair.
(English Translation of Jpn J Vasc Surg 2010; 19: 51-56.)
Keywords: thoracic aortic aneurysm, vascular surgery, endovascular surgery
IntroductIon
With advances in medical techniques in recent years,
surgical treatment for thoracic aneurysms has markedly
improved. The indications for surgery have expanded
to patients with complications and elderly patients, and
surgery has been actively performed. In 2008, com-
mercially available SG devices for thoracic aneurysms
began to be covered by insurance in Japan, and treatment
choices have increased. Therefore, the indications for
stent grafting (SG) for thoracic aneurysms are expected
to expand further.
Open surgery for thoracic aneurysms is an almost
established method. However, in many cases, its in-
vasiveness requiring thoracotomy and extracorporeal
circulation is a problem. On the other hand, since SG (tho-
racic endovascular aneurysm repair: TEVAR) is a new
treatment method, its long-term results are still unclear.
At present when there are many treatment choices, the
indications for both should be adequately considered, and
the most appropriate treatment strategy for each patient
should be selected. Although some studies have shown the
superiority of TEVAR, it is unclear whether open surgery
was selected for lesions strictly indicated for TEVAR.1, 2)
Department of Cardiovascular Surgery, Saitama Medical Cen-
ter, Jichi Medical University, Saitama, Saitama, Japan
Received: September 20, 2011; Accepted: December 6, 2011
Corresponding author: Koichi Yuri. Department of Cardiovascular
Surgery, Saitama Medical Center, Jichi Medical University, 1-847,
Amanuma-cho, Omiya-ku, Saitama, Saitama 330-0834, Japan
Tel: +81-48-647-2111, Fax: +81-48-645-0621
E-mail: kyuri@jichi.ac.jp
*This article is English Translation of Jpn J Vasc Surg 2010; 19:
51-56 .
Ann Vasc Dis Vol.5, No.1; 2012; pp15–20
©2012 Annals of Vascular Diseases doi: 10.3400/avd.oa.11.00920

Yuri K, et al.
16 Annals of Vascular Diseases Vol.5, No.1 (2012)
We retrospectively evaluated early and mid-term treat-
ment results in patients in whom both TEVAR and open
surgery could be anatomically selected, and compared
the two surgical methods.
SubjectS and MethodS
We performed a retrospective study in 213 cases with
a single thoracic aneurysm excluding acute aortic dissec-
tion, who were surgically treated in our hospital between
January, 2006 and August 31, 2009. All cases were classi-
ed according to the location of the lesion, and sizing of
the SG device was performed. SG was indicated in whom
the landing zone could be ≥15 mm from the left common
carotid artery on the proximal side and ≥15 mm from the
celiac artery on the distal side, the arterial diameter at the
landing zone was 20–38 mm, and excessive calcication
was absent. Of the 213 patients, 62 (29.1%) had indications
for SG in our center. When these patients were classied
according to the actually selected treatment, 30 patients
were classied as the TEVAR group (SG group) and the
other 32 as the open surgery group (OP group). The both
groups were retrospectively evaluated.
For TEVAR, the Tokyo Medical University (T.M.U.)
type SG device (Najuta, Kawasumi Laboratories, Tokyo)
was introduced in 2006, and a commercially available SG
device (TAG® W.L. Gore, USA) was introduced in Januar y
2008. Before the introduction of the commercially available
SG device, open surgery was the rst choice. After the in-
troduction of the SG device, SG was recommended as the
rst choice to high-risk patients such as those with many
comorbidities, but the surgical method was nally selected
by patients and their families with adequate, informed
consent. Preoperative respiratory disorders were dened
as those that require take-home oxygen therapy or treat-
ment for respiratory dysfunction on an outpatient basis.
Postoperative respiratory disorders were dened as those
that require controlled ventilation ≥72 hours after surgery.
All values are expressed as the mean plus standard
deviation, and statistical differences were analyzed us-
ing Student’s t-test and the χ2 test. The survival rate was
analyzed using the Kaplan-Meier and Log-rank methods.
P <0.05 was regarded as signicant.
reSultS
1. Patient background
The reasons for the selection of SG in the 30 cases in the
SG group are shown in Table 1. SG was selected due to
high risk in 21 cases (70%). The most frequent reason was
the patients’ wish, which was observed in 9 cases (30%).
These results did not always reect our selection criteria.
A T.M.U. type Najuta was used in 23 of the 30 cases
and a TAG® in 7. The proximal landing was further
than Zone 4 in 21 patients; the other 9 cases needed a
proximal landing zone from Zone 0 to Zone 3. In the
OP group, replacement of the descending aorta via left
thoracotomy was performed in 25 of 32 cases, and total
arch replacement using the median sternotomy, in 7. In all
cases in this group, extracorporeal circulation was used.
Four cases of descending aorta replacement performed
at a normal temperature and the other 17 cases were
performed under hypothermic circulatory arrest. In the
7 cases who underwent total arch replacement, the mini-
mum core temperature was 25°C, and distal circulatory
arrest/antegrade selective cerebral perfusion was used as
the standard procedure.
As shown in Table 2, there were no signicant dif-
ferences in the mean age, male/female ratio, presence/
absence of atherosclerosis risk factors, preoperative respi-
ratory dysfunction, emergency operation, or the history
of open heart surgery, between the SG and OP groups.
2. Early results
There were no operative deaths in either group, and
all cases in both groups were discharged on foot or
transferred to another hospital. Postoperative cerebral
infarction was observed in 3 cases in the OP group,
paresis in 2, in the SG group, and paraplegia in 1, in the
OP group. However, these conditions improved after
rehabilitation, and their incidence did not signicantly
differ between the two groups. The operation time, period
(days), until the initiation of postoperative oral intake, and
Table 1 Reasons for stent graft choice
Major specic indication Number %
Patient request 9 30.0
Advanced age 5 16.7
Cardiopulmonary disorder 4 13.3
Advanced age • post-thoracotomy 3 10.0
Central nerve disorder 3 10.0
Post-thoracotomy 2 6.7
Multiple a neurysms 2 6.7
Dialysis 1 3.3
Cancer 1 3.3

Stent Grafting and Open Surger y for Thoracic Aneurysms
17
Annals of Vascular Diseases Vol.5, No.1 (2012)
the postoperative hospital stay (days) were signicantly
shorter in the SG group, and the bleeding volume was
signicantly smaller in the SG group. The percentage
of blood transfusion and the incidence of postoperative
respiratory dysfunction were signicantly lower in the
SG group. Thus, the SG group was superior to the OP
group, in terms of early results (Table 3).
3. Mid-term results
During the follow-up period, for a mean of 656.4 w
547.8 days, 3 cases in the SG group and 4 in the OP group
died or dropped out, but no signicant differences were
observed between the two groups (P = 0.89). The 3 year
survival rate was 88.7% in the SG group and 87.1% in the
OP group (Fig. 1). The cause of death was pneumonia/
respiratory dysfunction in 2 cases, malignant tumors in 2,
multi-organ failure in 2, and hematemesis, resulting in
sudden death, in 1.
Events considered being associated with aneurysms
were observed in 1 case in the SG group. In the above pa-
tient who died of hematemesis, even though the aneurysm
at the original treatment site had decreased in size, a new
aneurysm formed central to the SG area and appeared
to have ruptured into the esophagus. The exact cause of
death was unclear, but infection of the SG device was
strongly suspected. In 2 patients in the SG group, Type
II endoleak persisted from immediately after the opera-
tion, and their courses have been strictly observed on an
outpatient basis despite no changes in the aneurysmal
diameter. There have been no cases undergoing open
surgery after TEVAR or additional TEVAR.
Table 2 Preoperative data
SG group (n = 30) OP group (n = 32) P value
Age (y.o.) 70.1w14.1 69.6w10.7 0.89
Gender (male: female) 25: 5 24: 8 0.41
Hypertension 12 15 0.92
Diabetes 4 5 0 .72
Chronic renal failure (Cr>1.5) 3 2 0.34
Chronic respiratory disorder 6 3 0.24
History of thoracotomy 5 4 0.64
Emergency 3 4 0.60
SG: stent graft; OP: open surgery
Table 3 Perioperative data and morbidity
SG group (n = 30) OP group (n = 32) P value
Replacement of the arch N/A 7
Replacement of the descending aorta N/A 25
Involvement of Zone 0–3 (+) 9 N/A
Involvement of Zone 0–3 (−) 21 N/A
Operative time (min) 198. 3w 87.9 413.1w121.9 <.0 01
Operative bleeding (ml) 154.2w167.48 1002 .3w89 5.1 <. 001
Blood transfusion (%) 3 (10. 0%) 19 (59.4%) <.001
Postoperative controlled ventilation (day) 1.0w0.0 3.41w3.9 0.016
Postoperative oral ingestion (day) 1.1w0 .4 6 .71w11.9 0.013
Cerebral infarction (%) 0 (0.0%) 3 (9. 3%) 0.051
Par apleg ia (%) 2 (6.6%) 2 (6.2%) 0.70
Postoperative hospital stay (day) 12 .4 w7.1 30.0 w2 6.1 <.001
Operative mort ality 0 0 N /A
SG: stent graft; OP: open surgery

Yuri K, et al.
18 Annals of Vascular Diseases Vol.5, No.1 (2012)
dIScuSSIon
In Japan, as SG devices for thoracic aneurysms, TAG®
(W.L. Gore, USA) and TALENT (Medtronic, USA) began
to be covered by insurance in 2008 and have been used
to the present. In addition, clinical trials on T.M.U. type
Najuta are in progress, in 11 institutions in Japan, and this
device is also expected to be covered by insurance in the
future. After the introduction of these devices, treatment
choices for thoracic aneurysms have increased. According
to the survey of the number of surgically treated cases
conducted by the Japanese Society for Vascular Surgery,
surgery for aneurysms in the descending aorta was
performed in 683 cases in scal year 2006, 922 cases in
2007, and 1214 cases in 2008, showing a marked increase.
Of 1214 cases, 682 (56.2%) were treated by TEVAR.
These values indicate the involvement of an increase in
the number of cases treated by TEVAR, and a rise in the
total number of surgically treated cases. However, the
number of cases treated by TEVAR has been increasing
without a general consensus regarding the relative merits
between open surgery and TEVAR and criteria for the
selection of treatment.
Some studies that compared the groups treated by
open surgery or TEVAR in other countries have shown
the superiority of TEVAR in short-mid-term results.1–3)
In Japan, a study, which compared the two methods us-
ing a home-made device for lesions located in the same
area, showed good early-mid-term results after both
open surgery and TEVAR, but a signicantly higher
mid-long-term incidence of aneurysm-related events after
T E VA R . 4) In this study, in the TEVAR group, the early
operative death rate was 2.5% (1 of 40 patients), but the
mid-term incidence of aneurysm-associated events that
occurred during 3 years was 17.9%, which was a high
rate, compared with conventional open surgery. Thus,
long-term follow-up is important even at present when
there are commercially available devices.
Although this was a retrospective study, the open
surgery and SG groups were very similar when the le-
sion localization and patient background were compared.
No operative death was observed in either group, and
early treatment results were favorable in both groups.
However, postoperative cerebral infarction was observed
in the open surgery group, but not in the SG group. In
addition, the SG group showed a signicantly smaller
bleeding volume, signicantly higher blood transfusion
rat e, and sig n i cant ly shor t e r posto p e r ative hosp ital st ay.
These results suggest that TEVAR is less invasive than
open surgery.
In this study, in the SG group, aneurysm-associated
death was observed mid-term after surgery, and Type II
leak persisted after TEVAR, in 2 cases, who have been
followed up to the present at the outpatient clinic, and
in 9 of 30 cases, the SG device was placed proximal to
Zone 3. In such cases, the proximal landing zone was
often short, due to the presence of branches in the cervi-
cal area compared with TEVAR distal to Zone 4 (Fig. 2).
Therefore, concerning the long-term results of TEVAR,
aneurysm-associated events should be carefully analyzed
by close follow-up.
The evaluation of 147 patients who underwent open
surgery for aneurysms in the aortic arch, in our institu-
tion, between 2000 and April 2008, showed no operative
Fig. 1 Kaplan-Meier Survival Curves for the each group.

Stent Grafting and Open Surger y for Thoracic Aneurysms
19
Annals of Vascular Diseases Vol.5, No.1 (2012)
death nor postoperative cerebral infarction in 97 patients
aged ≤75 years. However, in patients aged ≥75 years,
the operative death rate was 10%, and the incidence of
cerebral infarction was 8.3%. Based on these results, we
recommend TEVAR using commercially available SG
devices for high-risk patients, such as elderly patients,
as the rst choice and open surgery to relatively young
low-risk patients, considering that the long-term results
of TEVAR are still unclear. Comparison of the patients’
preoperative background between the two groups in
this study showed no signicant difference in each item
such as age. Although our policies were not always re-
ected, the reason for the selection of TEVAR widely
varied. We recommended open surgery to 9 patients in
the TEVAR group, but the patients themselves nally
selected TEVAR. This suggests marked demand for
minimal invasiveness at present. In addition, to reect
these results in future strategies, we intend to perform
closer, long-term follow up in these patients and analyze
aneurysm-associated events.
A questionnaire survey conducted in 2006 by the
Japanese Association for Thoracic Surgery showed that
arch replacement was performed by open surgery in
1544 (35.2%) of 4382 surgically treated patients with
non-ruptured thoracic aneurysms. The number of patients
who underwent this operation has been increasing. The
number of patients who underwent surgery of the de-
scending aorta was 535, also showing an annual increase.
The operative death rate was 4.5% each for aneurysms in
the aortic arch and those in the descending aorta, and the
early results of open surgery have annually improved.5)
While the surgical results have continuously improved,
medical companies and workers have made great efforts
to improve TEVAR devices, and their indications have
gradually been expanding. To expand the indications of
TEVAR to arch aneurysms, the T.M.U. type Najuta was
developed in Japan, which took the lead in developing
new devices, and favorable mid-long-term results have
gradually been reported.6) In the future, indications
for TEVAR are expected to expand further, due to an
improvement in development of devices for high-risk
patients in whom surgery was not conventionally indi-
cated, and the number of surgically treated patients with
thoracic aneurysms may also increase.
On the other hand, long-term results have not been ad-
equately claried. Makaroun et al.1) evaluated the 5 year
results of TEVAR using Gore TAG and reported that the
incidence of major adverse events related to open surgery
was 70% immediately after surgery, 77% after 1 year, and
78.7% after 2 years, but the incidence did not increase,
thereafter, until 5 years after surgery; however, that re-
lated to TEVAR using TAG was 28% immediately after
the operation, 42% after 1 year, and 57.9% after 5 years,
showing a slight increase. Therefore, in young patients
who require long-term follow-up, the risks and benets
of TEVAR should be adequately evaluated for treatment.
concluSIonS
The early-mid-term results of both TEVAR and open
surgery were favorable, but TEVAR was less invasive.
While the results of open surgery have improved, devices
for TEVAR have been developed. In high-risk patients,
the selection of less invasive TEVAR may be appropri-
ate. However, not all problems regarding the long-term
results have been overcome. According to age and the
Fig. 2 A case of TEVAR.
A: before deployment of SG.
B: after deployment of SG. The proximal landing was at Zone 1.
TEVAR: thoracic endovascular aneurysm repair; SG: stent graft

Yuri K, et al.
20 Annals of Vascular Diseases Vol.5, No.1 (2012)
general condition of the patient, open surgery may be the
rst choice. Surgical results may further improve, and
indications may further expand by selecting treatment
methods with consideration given to the advantages of
both TEVAR and open surgery.
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