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N. Kato et al. Chapter 20 Endografts for Chronic Dissections
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stents can easily dilate it. Therefore, endografts can almost fully expand and become round at both the top
and the bottom ends after the treatment even if the true
lumen is markedly compressed by the false lumen and
is paper-thin (Fig. 20.6). Thus, stents could be simply
cylindrical with a round shape at both ends. In contrast, endografts do not always become round in the
case of chronic dissection, especially at the distal end
since the intimal flap is fibrotic and rigid (Fig. 20.7).
Thus, stents have to be able to accommodate to the
shape of the deformed true lumen in the case of
Fig. 20.5. So-called first-generation endograft which is fabri-
cated with Z-stents and polytetrafluoroethylene
chronic dissection. Z-stents have sufficient compressibility to fulfill this demand.
An anchoring device such as a hook is mandatory
for the treatment of true aneurysms of the thoracic or
the abdominal aorta to avoid migration. However, it
which are fabricated with Z-stents and polyester or expanded polytetrafluoroethylene (ePTFE), still work well
in the treatment of aortic dissection as well as in that of
thoracic aortic aneurysms [4, 16] (Fig. 20.5).
The design of the stent configuration is important
when chronic dissection is treated. In the case of acute
dissection the intimal flap is stretchable enough that
might not be preferable in the case of dissection since
it could make a new intimal tear when there is an intimal flap at the level where the hooks are supposed to
be located. In addition, such an anchoring device may
not be necessary because the landing zone is tapered
distally in most dissection cases and such tapering of
the landing zone could prevent migration of devices.
203
ab
Fig. 20.6. The bottom end of the endograft, which was narrow and deformed before treatment (a), fully expands and is round
1 year after endografting (
ab
Fig. 20.7. The bottom end of the endograft seems almost the same before (a) and after (b) endografting, i.e., it does not fully ex-
pand and is still deformed 1 year after endografting
b) in the case of acute dissection
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IV. Dissection
The size of the endografts is always a key to successful treatment. Endografts the diameters of which are
approximately 10±15% larger than that of the landing
zone are used as in the case of thoracic aortic aneurysms. The diameter of a circle which has the same circumference as the landing zone needs to be estimated
since the landing zone is usually deformed in the case
of aortic dissections. It can be calculated by dividing
the circumference of the landing zone by p. More easily
the mean of the shorter and the longer diameter of the
landing zone can be substituted for it.
The other thing to be memorized is that the intimal
flap does not always expand fully in the case of chronic
dissection, especially when dissections older than 1 year
are treated. Therefore, tapered endografts might be suitable for chronic dissections instead of straight endografts, which are usually sufficient for acute dissections,
since the use of a straight one could lead to intimal injury because of too much hoop strength at the more deformed and narrower true lumen at the bottom end.
20.6.2 Procedures
Since the procedure itself is basically the same as that
used for the treatment of thoracic aortic aneurysms, the
details of the procedures are abbreviated in this chapter.
The only difference from true aneurysms is that there
are two lumens in the case of aortic dissections. A catheter and a wire inserted from the femoral artery can
easily go into the false lumen when there is a large reentry tear. Thus, careful monitoring of the advancement
of a catheter with occasional test injections at various
levels to confirm the catheter is in the true lumen is
mandatory. When it is difficult to enter the true lumen
from the femoral artery, the true lumen can be obtained
by advancing a catheter and a wire from the brachial
artery to the femoral artery.
Completion angiography after deployment of the device must be carefully appreciated in the case of aortic
dissections. The false lumen is sometimes rapidly opacified by contrast medium entering from natural fenestrations or reentry and it may resemble type I endoleak,
although the false lumen is thrombosed soon or later
even in such cases.
When type I endoleak is observed after deployment
of an endograft, balloon dilatation can be applied. However, meticulous inflation is required to avoid making
new intimal injuries although the possibility should be
small compared with that in the case of acute dissection.
20.6.3 Postoperative Care
Postimplantation syndrome including high fever continuing for about 1 week is almost always observed. It
can be easily controlled with antifebrile. Transient increase of C-reactive protein and white blood cells is also
observed as well. However, the levels also subside together with fever [18, 28] and there is no need to treat
them.
Paraplegia, which is one of the most catastrophic
complications accompanying surgical graft replacement,
reportedly develops in approximately 5% of patients undergoing endografting, which is comparable to or less
than that of surgical intervention [4, 5]. It may develop
immediately or late after endografting [14]. To avoid
this challenge, cerebrospinal fluid drainage seems useful
as well as in the case of graft replacement for the treatment of thoracoabdominal aortic aneurysms [3, 10, 35].
Strict control of blood pressure and close follow-up
by CT even after endografting should be a must. Those
patients who have suffered aortic dissection may have a
higher chance of development of a new dissection at another segment of the aorta. In addition, once dissected
the aorta may not be normal even if the false lumen is
completely thrombosed by endografting. Fortunately,
there is no patient who underwent endografting for the
treatment of chronic aortic dissection and had a new
dissection thereafter in our hospital; type A aortic dissection developed in one patient who underwent endografting for the treatment of acute type B dissection.
Type A aortic dissection with a new intimal tear in the
ascending aorta developed in another patient who underwent endografting for the treatment of acute type A
dissection with the intimal tear in the descending thoracic aorta.
Follow-up CT is obtained 1 week after the treatment,
1 month, 3 months, 6 months, 1 year, and yearly thereafter in our hospital. It is not rare that only the true lumen is densely opacified in the early phase of contrastenhanced CT since the flow into the false lumen of the
descending thoracic aorta coming up from fenestrations
or reentry is relatively slow. Therefore, delayed scan is
mandatory to recognize the exact extent of thrombosis
in the false lumen. Whenever any problem, including
type I endoleak and new intimal injury, is observed, additional procedures have to be planned immediately.
The false lumen of the descending thoracic aorta
sometimes remains patent because blood flow coming
from fenestration or reentry is sometimes directed to
such aortic branches as bronchial arteries or intercostals arteries which are supplied totally from the false lumen. However, the false lumen finally thromboses during follow-up in most cases unlike type II endoleak,
which is often observed in cases of abdominal aortic
aneurysms.
N. Kato et al. Chapter 20 Endografts for Chronic Dissections
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20.7 Results of Endografting
Nienaber et al. [29] should be credited as being first to
objectively prove the efficacy of endografting for the
treatment of chronic aortic dissection. They treated 24
patients with chronic aortic dissection: 12 patients with
endografting and 12 patients with surgical graft replacement. Endografting was associated with no mortality or morbidity, whereas conventional surgery was associated with four deaths and five serious adverse
events in their series. Although the number of the patients and the follow-up term in their series are extremely limited, their results were so impressive that
those who had been hesitating to repair chronic dissection with endografts were encouraged.
From 1997 to 2004, 29 patients with chronic aortic
dissection were treated with endografting in our hospital [19, 21]. ªChronicº is referred to as those dissections
present for 1 month or more. The characteristics of the
patients are listed in the Table 20.2. Indications for endografting are shown in Fig. 20.8. There was no death
within 30 days (Table 20.3). Intraoperative complications were observed in two patients. Minor intimal injury at the external iliac artery caused by inserting the
delivery system was repaired with stenting in one patient. Another patient with arterio-venous fistula for hemodialysis in the left forearm complained of left arm
pain immediately after anesthesia wore off. Since the
origin of the left subclavian artery was closed with an
endograft, ischemia was deemed the cause of pain. The
symptom disappeared after creating a bypass between
both axillary arteries.
There was no major complication including cerebral
infarction, spinal ischemia, and type I endoleak. The
false lumen of the descending thoracic aorta was partially patent in two patients. Type II endoleak to which
the bronchial artery contributed was observed in one
patient. In the other patient blood entering from the
natural fenestration came up the false lumen of the descending thoracic aorta and flowed into the intercostal
artery. The false lumen of the descending thoracic aorta
was completely thrombosed in the other 27 patients.
Early postoperative complication was observed in one
patient who suffered wound infection at the skin incision site.
During a mean follow-up term of 40 Ô 26 months
(range 1±93 months) there was no late death (Table
20.4). In addition, no device-related complications were
observed. ULP developed at the descending thoracic aorta in two patients 2 and 3 years after endografting, respectively. Hemoptysis developed in one patient 3 months
after endografting, although its cause was not elucidated.
Complications which were not related to aortic dissection
or devices were observed in two patients, lung cancer in
one patient, and abdominal aortic aneurysm independent
of aortic dissection in other patient.
Fig. 20.8. Indications of endografting. 1 aortic diameter greater
than 50 mm on CT, 2 aortic diameter greater than 40 mm on
CT in a dissection present for 1 month or less, 3 enlargement
of an ulcerlike projection during follow-up, 4 persistent back
pain despite medical therapy
Table 20.2. Patient characteristics
Age (years) 60 Ô13
Male sex 24 (83%)
Maximal diameter of the descending thoracic
aorta (cm)
Dissection-related complications 0 (0%)
Dissection-unrelated complications 24 (83%)
Hypertension 18 (62%)
History of ascending aortic replacement 4 (14%)
Abdominal aortic aneurysm/thoracic aortic
aneurysm
Coronary arterial disease 3 (10%)
Renal failure 2 (7%)
Marfan syndrome 2 (7%)
Coagulopathy 1 (3%)
Table 20.3. Early mortality and morbidity
Mortality 0 (0%)
Complication 5 (17%)
Aorta-related 2 (7%)
Intimal injury 0 (0%)
Type I endoleak 0 (0%)
Type II endoleak 2 (7%)
Aneurysmal degeneration 0 (0%)
Aorta-unrelated 3 (10%)
Stroke 0 (0%)
Paraplegia 0 (0%)
Left arm ischemia 1 (3%)
Dissection of iliac artery 1 (3%)
Wound infection 1 (3%)
47 Ô9
3 (10%)
Remodeling of the aorta occurred during follow-up.
The aorta and the false lumen shrank, while the true lumen expanded. However, it is not as conspicuous as in
case of acute dissection, in which the false lumen often
disappears and the aorta recovers its original diameter.
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IV. Dissection
Table 20.4. Late mortality and morbidity
Mortality 0 (0%)
Complication 5 (17%)
Aorta-related 4 (7%)
Intimal injury 0 (0%)
Type I endoleak 0 (0%)
Type II endoleak 2 (7%)
Aneurysmal degeneration 2 (7%)
Aorta-unrelated 1 (3%)
Hemoptysis 1 (3%)
20.8 Summary
Although further follow-up is mandatory, endografting
for the treatment of chronic type B aortic dissection is
seemingly a superior alternative to surgical graft replacement in terms of short and midterm results, even
if first-generation endografts are used. To expand indication more sophisticated devices such as branched or
fenestrated endografts should be necessary.
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Problems Encountered During
https://t.me/med1917
and After Stent-Graft Treatment
of Aortic Dissection
Jong Yun Won, Do Yun Lee
Chapter
21
Contents
21.1 Introduction ......................
21.2 Materials and Methods ................ 209
21.2.1 Patients .................... 209
21.2.2 Imaging .................... 210
21.2.3 Stent-Graft ................... 210
21.2.4 Procedures .................. 210
21.2.5 Follow-Up ................... 210
21.3 Problems During the Procedure ...........211
21.3.1 Stent-Graft Migration ............ 211
21.3.2 Complications Related to the Size
oftheStent-Graft...............
21.3.3 Appearance of a Hidden Intimal Tear
intheDTA ..................
21.3.4 Type I Endoleak ............... 212
21.4 Problems During the Follow-Up ...........212
21.4.1 Postimplantation Syndrome ........ 212
21.4.2 Neurologic Complication .......... 214
21.4.3 Persistent Type I Endoleak ......... 214
21.4.4 Type II Endoleak ...............215
21.4.5 Progressive Abdominal Aortic Aneurysm . 215
21.4.6 New Intimal Tear ............... 217
21.4.7 Mechanical Failure of the Stent-Graft . . . 219
21.5 Conclusion ....................... 221
209
211
212
21.1 Introduction
Aortic dissection is one of the life-threatening diseases
involving the aorta whether it is acute or chronic [7,
23]. The conventional treatment strategy depends on
the extension of the dissecting process: surgical repair
of the aortic replacement with prosthetic graft when it
involves the ascending aorta (Stanford type A), and
medical treatment when it involves the descending thoracic aorta (DTA) (Stanford type B). However, more
than 20% of patients with Stanford type B aortic dissection need surgical intervention for the various indications: an expanding false lumen of dissection, branch
vessel and leg ischemia, recurrent pain, or impending
rupture [8, 31]. Because of high surgical morbidity and
a mortality rate around 20±60% [9, 34], endovascular
stent-graft placement has emerged as a new treatment
modality as a substitute for open surgery in aortic dissection with a descending aortic intimal tear and many
authors have reported their encouraging results of more
than 60% of complete thrombosis or resolution rate [1,
3, 5, 21, 37].
However, because of the very limited number of patient populations and the duration of follow-up, many
questions are still controversial. Especially, only a few
reports have concerned the various problems which can
be encountered in stent-graft treatment of the aortic
dissection [15, 16]. In this article, we present our experiences and review other authors' reports about these
problems encountered during the procedure of stentgraft placement and the follow-up period in patients
with aortic dissections.
21.2 Materials and Methods
21.2.1 Patients
Between July 1994 and December 2003, 60 patients with
aortic dissections who underwent stent-graft placement
in the DTA were included in this study. The protocol
was approved by the Institutional Review Board, and
informed consent was obtained from all patients. The
39 men and 21 women ranged in age from 37 to
88 years (mean 59 years). The inclusion criteria for the
stent-graft were type A with retrograde dissection and
an intimal tear located in the DTA, type B dissection
with dynamic obstruction of abdominal aortic branch
vessels, persistent or recurrent pain, aortic rupture, and
an aortic diameter greater than 40 mm in the acute
phase of dissection or greater than 60 mm in the
chronic phase [22]. Five of nine patients with type A
dissections had retrograde dissection with a primary
entry tear located distal to the left subclavian artery
(SCA). Therefore, a stent-graft was available for the
treatment of this rare type of dissection. The other four
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IV. Dissection
patients, including two with Marfan syndrome, with
type A dissection had previously undergone surgical replacement of the ascending thoracic aorta and the aortic arch, leaving a large reentry tear in the DTA. Ten
patients presented acute (less than 2 weeks) symptoms;
50 patients had chronic (2 weeks or more) symptoms
[24]. The location of the primary entry tears were at
the proximal DTA in 38 patients and at the mid to distal DTA in 22 patients. All aortic dissections simultaneously involved the abdominal aorta below the level of
the diaphragm, with contiguous extension. The distal
extents of the dissections were variable from the suprarenal abdominal aorta to both iliac arteries. All patients
showed patent false lumen flows from the proximal primary entry tear to the distal several reentries in the abdominal aorta or the iliac artery.
21.2.2 Imaging
Before the procedures, all patients underwent contrastenhanced spiral computed tomography (CT) scans and
digital subtraction aortograms in order to measure the
dimension of the aorta and to evaluate entry and reentry tears. Conventional spiral CT scans of the aorta were
evaluated using the following parameters: collimation of
7 mm with a table feed of 7 mm/s, 2-mm reconstruction, 120 kV, and 220 mA s. The patients received 120±
150 ml of contrast medium at a rate of 3.0 ml/s. Recently, we used a 16-channel multidetector row CT scan
(Somatom Sensation 16, Siemens, Forchheim, Germany)
with the following parameter: table feed of 15 mm, gantry rotation time of 0.5 s, tube voltage of 120 kV, amperage of 150 mA m, 2-mm reconstruction. Between 10
and 15 s after the end of the arterial phase acquisition,
a second acquisition was performed. The aortography
was performed with the use of a calibrated marker catheter (Cordis, Roden, The Netherlands). We injected 25±
30 ml of contrast medium at a rate of 15 ml/s and obtained six to ten images per second for the thoracic aorta and two to six images per second for the abdominal
aorta. Angiographies of the femoral, external iliac, and
common iliac arteries allowed accurate sizing of these
arteries and evaluation of tortuosity for the adequate
vascular access.
21.2.3 Stent-Graft
We used two different kinds of stent-graft. Until the
end of 1999, we implanted a homemade Z-shaped stent
covered with balloon-dilated poly(tetrafluoroethylene)
(Impra, Tempe, AZ, USA) material in 20 patients. Since
then, we have implanted our self-designed percutaneous
separated stent-graft that can be deployed percutaneously through a 12-French low-profile introducer. The
new device consists of two separate bodies: the main
body with two anchoring stents at both ends connected
by a Dacron graft and the second body of an inner nitinol bare stent. This unique structure enables percutaneous deployment and less resistance against blood
flow during deployment, so we could implant the stentgraft without any blood pressure, lowering medication
[14]. Each stent-graft was individually constructed and
manufactured to be 10±15% larger than the diameter of
the unaffected aorta proximal to the entry tear of dissection. The mean diameter and the mean length of the
stent-graft were 33 Ô 4 mm (24±40 mm) and 9.6 Ô 2.0 cm
(6.0±15.0 cm).
21.2.4 Procedures
The method of Z-shaped stent-graft placement was almost the same as those described in a previous report
[20]. All procedures were performed in angiography
units under local or epidural anesthesia and full hemodynamic monitoring while placing the patients in the
supine position. Vascular access was obtained through
the femoral artery following surgical cut-down. After
inserting an exchange (260-cm) 0.035-in.-diameter Amplatz superstiff guidewire (Boston Scientific, Watertown,
MA, USA), we advanced the 20- or 22-French stentgraft delivery sheath (Keller-Timmerman Sheath, Cook,
Bloomington, IN, USA) over the guidewire. The patient
was anticoagulated with intravenous heparin (5,000 IU)
before the insertion of the stent-graft delivery sheath.
After that, we deployed the stent-graft by rapidly withdrawing the introducer sheath. Aortography via a contralateral percutaneous femoral artery approach with a
5-French multisidehole catheter (Cook, Bloomington,
IN, USA) was performed before and after the stent-graft
deployment in order to confirm the exact location of
the stent-graft, the absence of perigraft leakage, and the
patency of adjacent branch vessels.
Deployment of the percutaneous separated stentgraft needs slightly different steps from conventional Zshaped stent-graft. First, the main body of the stentgraft is deployed and subsequently the bare stent is deployed inside the main body. In addition, deployment
of a percutaneous separated stent-graft was performed
through a 12-French low-profile introducer under local
anesthesia without surgical cut-down. Recently the
puncture site has been closed using a Perclose device
(Abbott Vascular Devices, Redwood City, CA, USA).
21.2.5 Follow-Up
Follow-up spiral CT scans were performed within
1 month of the procedures, then at 3±6-month intervals
for 2 years, and annually thereafter. Each patient was
J. Y. Won, D.Y. Lee Chapter 21 Problems Encountered During and After Stent-Graft Treatment of Aortic Dissection
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211
Table 21.1. List of problems encountered in stent-graft place-
ment for aortic dissection
Problems during the procedure
Stent-graft migration
Stent-graft torsion
Complication related to the size of the stent-graft
Appearance of a hidden intimal tear in the descending
thoracic aorta
Type I endoleak
Problems during follow-up
Postimplantation syndrome
Neurologic complication
Persistent type I endoleak
Type II endoleak
Progressive abdominal aortic aneurysm
New intimal tear
Mechanical failure of the stent-graft
followed for 9±103 months and the mean follow-up was
31 months. Technical success was defined as the completion of the stent-graft deployment at the target area
without stent-graft failure. Clinical success was defined
as complete exclusion of the primary entry tear from
the circulation without a significant adverse cardiovascular event by serial CT. We assessed all technical
problems during the procedure and complications
which occurred during the follow-up period (Table
21.1).
on the follow-up CT scan. The patient is under close
observation for 16 months. Since changing the device to
a separated stent-graft, the migration problem has no
longer happened. Many investigators are known to design their own devices which enable a better proximal
fixation, using stent appendages such as hooks or barbs
and a rapid deployment system using a pull-string to
avoid this unfavorable complication [12, 35].
21.3.2 Complications Related to the Size
of the Stent-Graft
The method of measuring the adequate size of the
stent-graft in aortic disease seems to be an subject that
needs general consensus, especially in aortic dissection.
Investigators determine the diameter of a stent-graft in
many different ways. We use the diameter of the proximal unaffected aorta as a base line and manufacture the
21.3 Problems During the Procedure
21.3.1 Stent-Graft Migration
Migration of the stent-graft caused by the ªwind sockº
effect of ventricular ejection results predominantly in
technical failure, particularly when proximal fixation is
at or near the aortic arch [2]. To avoid this serious
technical problem, lowering the blood pressure with a
vasodilator or beta-blocker drugs has been done [16,
25]. Despite this effort, stent-graft migration has reported to occur with an incidence of 2±20% by many
authors [29].
In our experience, we observed two cases (3%) of
stent-graft migration, which occurred in two patients in
our early period when we used a single stent-graft system and nitroprusside to lower the blood pressure during deployment of the stent-graft. Primary entry tears
of those two patients were located at the proximal DTA,
3 and 5 cm from the left SCA. We attempted to correct
the location of the stent-graft with a balloon, but failed.
We deployed an additional stent-graft and successfully
excluded the primary entry tear in one patient. However, in the other patient, an additional stent-graft of
adequate size was not readily available. Later, the patient refused further intervention and his false lumen
remained patent without demonstrable interval changes
a
b
Fig. 21.1. Stent-graft folding. A 56-year-old man with De Bakey
type III chronic aortic dissection.
mography (CT) scan shows the true lumen and the false lumen
of the descending thoracic aorta.
CT scan after the stent-graft treatment. Despite inward folding
of the stent-graft strut (arrow), complete resolution of the thoracic false lumen is achieved
a Preoperative computed to-
b Fifty-two-month follow-up
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IV. Dissection
stent-graft 10±15% larger. Shimono et al. [33] use a
stent-graft 10% larger than the average of the maximum
and minimum diameters of the thoracic true lumen in
acute dissection and 20% in chronic dissection. Choosing a stent-graft diameter that is too small can cause an
endoleak or migration, whereas oversizing of the prosthesis may lead to infolding of the graft. In the experimental report of Schurink et al. [32], oversizing and
folding of the stent-graft were significantly related to
the grade of the endoleak, and balloon expansion can
not help to reduce the endoleak.
Among 60 patients of our study, two stent-grafts
(3%) were infolded during deployment, which was
caused by overestimation of the stent-graft size. On the
follow-up CT scan, those stent-grafts were not expanded
even after the aortic true lumens had been fully expanded. Fortunately, primary entry tears of these two
patients were completely excluded and there was no
thrombus formation around the deformed stent-graft
on follow-up CT scans taken 46 and 55 months after the
procedure (Fig. 21.1). We keep following these patients
closely because of the possibility of blood flow disturbance inside the aorta by the protruding stent strut.
21.3.3 Appearance of a Hidden Intimal Tear in the DTA
have further intervention because a suitably sized device was not readily available. Despite persistent contrast enhancement of the thoracic false lumen in these
two patients, gradual decrease of the aortic diameter
was seen on serial follow-up CT scans at 6 and
27 months each (Fig. 21.2).
In our institute, very thin sections of spiral CT scans
of less than 2-mm slice thickness and a three-dimensional reconstruction image combined to aortograms
with a high frame rate of more than 6 frame/s and
oblique views perpendicular to the aortic intimal flap
are obligatory for the preoperative evaluation for the
aortic dissection. Recently, the multidetector CT scan
became available and enables more accurate evaluation
of aortic dissection by its greater spatial resolution,
thinner slice thickness, and faster scan time [17]. Despite careful evaluation of the preoperative images, we
lost three cases of proximal and distal hidden intimal
tears which were relatively small compared with the adjacent primary entry tear. Pamler et al. [26] suggested
obtaining many preoperative aortograms with the catheter tip at different levels. They also propose covering
every intimal tear in the thoracic aorta with a stentgraft to prevent distal reperfusion of the false lumen.
21.3.4 Type I Endoleak
Many authors mentioned the importance of verifying
every intimal tear of the thoracic aorta on preoperative
imaging. Especially in long-standing chronic dissections, it is more important owing to the possibility of
multiple fenestrations in the DTA and the abdominal
aorta. In chronic dissections, along with fibrosis, contraction of the myointima, and dilated outer layers, even
a small intimal tear could disturb reattachment of the
intima to the outer media and adventitia [17, 20]. According to our experience, every thoracic false lumen of
acute dissection was decreased in size only with the exclusion of the primary entry tear. However, in chronic
dissection, the size of the thoracic false lumen did not
decrease until every intimal tear including the primary
entry tear was excluded. In addition, the time required
for complete thrombosis of the thoracic aortic false lumen was longer in the chronic dissections, as was the
resolution time. Those differences might be related to
the formation of the multiple thoracic reentry tears, the
status of endothelialization in the false lumen, and the
endotension caused by reentry tears.
In three patients (5%) with primary entry tear in the
distal DTA of our series, initially undetected hidden intimal tears appeared within 2 cm of the proximal (n=1)
and the distal (n=2) margins of the stent-graft which
had been successfully deployed upon the primary entry
tear. All of their dissections were acute. One of them
underwent additional stent-graft deployment upon the
hidden intimal tear. The other two patients could not
Twelve endoleaks (20%) were detected immediately after
the successful deployment of the stent-graft and all of
them were type I endoleaks (attachment site endoleak)
at the proximal margin of the stent-graft. Ten of the
twelve patients with endoleaks had a primary entry tear
in the aortic arch and the proximal DTA and one of
them was located in the lesser curvature side.
21.4 Problems During the Follow-Up
21.4.1 Postimplantation Syndrome
Postimplantation syndrome can be manifested in various symptoms and signs, such as fever, leukocytosis,
elevated C-reactive protein level, pleural effusion, and
decreased platelet count.
Fever, leukocytosis, and elevated C-reactive protein
level, of which the incidence is known to be 20±60%,
are suggested to be a nonspecific systemic inflammatory
reaction rather than true infection. However, it has been
reported to result in little prolonged complication by
many authors [20, 36]. In our early experiences, we routinely medicated prophylactic antibiotics; however, this
did not help to lower the incidence of postimplantation
syndrome. All the patients recovered with conservative
treatments in 2±10 days. Many institutes manage these
J. Y. Won, D.Y. Lee Chapter 21 Problems Encountered During and After Stent-Graft Treatment of Aortic Dissection
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213
a
c
Fig. 21.2. Emergence of hidden intimal tear. A 66-year-old man
with De Bakey type III acute aortic dissection.
aortogram demonstrates a large entry tear located at the distal
descending thoracic aorta near the diaphragm (arrow). No
other entry tear is defined in the descending thoracic aorta.
Immediately after the stent-graft deployment, the completion
b
d
a Preoperative
aortogram shows exclusion of the entry tear and nonvisualization of the false lumen.
ment, emergence of a hidden entry tear (arrow) is depicted
just above the stent-graft on CT (
b
right anterior oblique view (d). Contrast enhancement of the
thoracic false lumen is still noted
c,d One week after the stent-graft treat-
c) and aortograms of 508
complications only with anti-inflammatory agents or
even without any medication and recommend judicious
use of antibiotics [12, 25, 30].
Pleural effusion and decreased platelet count are not
well-known complications of stent-grafts in aortic dissection. In our series, 34 patients (57%) with pleural ef-
fusion and 22 patients (37%) with decreased platelet
count to more than 50% of the base line were observed
during the follow-up. All patients with pleural effusion,
which we suggest to originate from foreign-body irritation to the adjacent pleura, showed complete resolution
on 1-month (n=25) or 3-month (n=9) follow-up CT
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