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Thoracic Endovascular Aortic Repair Chapter | 40 447
Algorithm for Type B TAD Management
optimal medical therapy; OSR, open surgical repair
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TABLE 40.1 Indications of the Thoracic Endovascular Aortic Repair
I. Aortic Dissection
A. Unstable acute/chronic type B dissection
B. Malperfusion syndrome
C. Persisting or recurrent pain
D. Refractory hypertension
E. Rapid expansion (yearly increase of total aortic diameter of >4 mm)
F. Critical diameter (≥55 mm)
G. Impending rupture (hemothorax, increasing periaortic, and mediastinal hematoma)
H. Symptomatic penetrating aortic ulcer
I. Progressive or complicated intramural hematoma
J. Type B dissection with retrograde extension into the ascending aorta
K. Hybrid procedure for extended type A aortic dissection
II. Thoracic Aortic Aneurysm
A. Critical diameter (≥55 mm)
B. Rapid expansion (>5 mm in 6 months)
C. Chest discomfort, symptoms of surrounding organ compression (new onset hoarseness, dysphagia, dyspnea, hemoptysis)
III. Traumatic Aortic Injury
A. Complete transection of the aortic wall and free bleeding into the mediastinum
B. Pseudocoarctation syndrome
Acute Type B TAD
(within 2 weeks)
Subacute (2 weeks to 6 weeks)
& chronic (> 6 weeks) B Type B TAD
Impending rupture
Malperfusion syndrome
Refractory hypertension
Hypotension (<90 mm Hg systolic)
Shock
YES
TEVAR
OSR (if TEVAR
contraindicated)
OMT & imaging surveillance
protocol:
admission, 7 days
discharge, 6 weeks, 3 months,
6 months & annually thereafter
NO YES NO
Critical aortic diameter ≥ 55 m
Rapid expansion (aortic diameter > 4mm/year)
New onset periaortic hematoma / hemothorax
Recurrent symptoms
TEVAR
OSR (if TEVAR
contraindicated)
OMT & imaging surveillance
protocol:
6 weeks, 3 months,
6 months &
annually thereafter
Abbreviations: TAD, thoracic aortic dissection; TEVAR, thoracic endovascular repair; OMT,
FIGURE 40.2 Algorithm for thoracic aortic dissection management.
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(A)
(C)
(B)
(D)
FIGURE 40.3 (A) Computed tomography angiography (CTA) depicting type B thoracic aortic dissection, (B) digital subtraction angiography (DSA) showing
crossing the lesion, (C) DSA postthoracic endovascular aortic repair, (D) CTA showing stent graft.
TABLE 40.2 Predictors of Aortic Growth in Uncomplicated Type B Thoracic Aortic Dissection [19]
l
Marfan’s syndrome
l
Serum fusiform-fibrin degradation product level≥ 20 μg/mL on admission
l
Aortic diameter ≥ 40 mm during acute phase
l
Patent false lumen (FL)
l
Proximal descending thoracic aorta FL ≥ 22 mm on initial imaging
l
FL/intimal tear located at inner aortic curvature
l
An elliptical configuration of the true lumen/round configuration of FL
l
Areas with localized dissection/ulcer-like hematoma
l
Degree of fusiform dilatation of the proximal descending aorta (fusiform index ≥ 0.64)
l
Large entry tear (≥10 mm) located in the proximal part of the dissection
mediastinal hematoma) [20]. Diagnosis of static or dynamic organ malperfusion is corroborated by laboratory markers
(bilirubin, amylases, enzymes, creatinine) and imaging data. It carries a mortality between 50% and 85% if untreated and
is largely the result of severe proximal compression of the true lumen (TL) in the chest by pressurized and bulging FL.
The aortic branch closure could be due to either static mechanisms (branch vessel compression by the pressurized FL)
or dynamic mechanisms (protrusion of a dissection flap into the branch-vessel origin). With this understanding, the most
effective way of relining the TL in proximal and mid-descending aorta is with a stent graft to obliterate the entry site and
redirect all blood flow down the TL [21]. The Provisional Extension to Induce Complete Attachment concept incorporates
the idea of endothoracic repair even further by extending the stent graft distally further with open-cell bare metal stents
Thoracic Endovascular Aortic Repair Chapter | 40 449
(A)
(B)
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(C)
FIGURE 40.4 (A) Computed tomography angiography (CTA) showing thoracic aneurysm, (B) digital subtraction angiography (DSA) depicting thoracic aneurysm, (C) DSA following thoracic endovascular aortic repair, (D) CTA depicting stent graft.
until distal malperfusion is corrected [22]. With this new understanding, the role of direct branch vessel stenting or use of
(D)
fenestration has diminished significantly. A metaanalysis done on 1304 patients of acute type B TAD subjected to TEVAR
demonstrated 99% technical success and 2.6% 30-day mortality [23]. At late follow-up, thrombosis of FL, surgical conversion, and endovascular reintervention were reported in 92.6%, 0.8%, and 1.6%, respectively [22]. Neurological complications and retrograde extension were documented in 0.6% and 0.4%, respectively [23].
TEVAR FOR TAA
TEVAR is recommended in asymptomatic TAA patients when the aneurysm diameter exceeds 5.5 cm or there is rapid
expansion (>5 mm in 6 months) (Fig. 40.4) [16,24]. It is also recommended when symptoms develop that are attributable
to TAA irrespective of size, such as chest pain, back pain, dysphagia, hemoptysis, or aortic regurgitation with heart failure.
TEVAR may be justified at a diameter <5.5 cm in certain morphological features considered prone to rupture such as saccular aneurysms (Table 40.1). Lower cutoffs (4–5 cm) for TEVAR is recommended for Marfan’s syndromes and Loeys–Dietz
syndrome [24]. TEVAR has emerged as a promising and less invasive therapeutic alternative to OSR. The stent graft bridges
the aneurysmal sac to exclude it from high-pressure aortic blood flow leading to sac thrombosis around the endograft and
possible aortic wall remodeling.
Mortality for OSR compared to TEVAR tends to be higher and ranges from 5% to 20% in elective cases and up to 50%
in emergent conditions [25,26]. Paraplegia from spinal cord ischemic injury occurs in 5%–25% cases of OSR compared
with 1% in TEVAR [25,26].
A sufficient proximal and distal landing zone of at least 2 cm is necessary for the safe and durable fixation of TEVAR
[27,28]. Prior transposition or bypass surgery/rerouting of the involved aortic branch may be considered in case of short
and angulated landing zones. Given its avoidance for great vessels proximally and major branches and aortic bifurcation
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distally, thoracic aorta is more amenable to TEVAR. Despite this, TEVAR has progressed more slowly than infrarenal
counterpart because of more aggressive hemodynamic forces of thoracic aorta (causing device migration, kinking, and late
structural failure), requirement of greater flexibility of the thoracic device to curvature and tortuous anatomy, and requirement of larger device to match the diameter of this segment of the aorta causing arterial access to be more problematic.
TEVAR FOR TRAUMATIC AORTIC INJURY AND CONNECTIVE TISSUE DISORDER
The patients with complete transaction of aorta with bleeding into the mediastinum or pesudocoarction syndrome would
warrant immediate TEVAR, whereas delayed treatment could be offered when there is limited disruption of aorta with
intact media and adventitia [29–31]. TEVAR should not be recommended in patients with connective tissue disorder except
as a bridge or bail-out procedure to OSR.
CURRENT TECHNICAL ASPECTS OF TEVAR
Vascular Access, Techniques, and Specifics
Evaluation of access vessels (sizing, calcification, tortuosity) is of major importance. An access vessel of at least 8 mm in
diameter is necessary for a standard 24-French delivery device. Alternative access sites are the iliac arteries, the infrarenal aorta, the right brachial, or even the ascending aorta. Surgical cutdown is traditionally regarded as the safest way to
fully control access vessels. There is an upsurge in percutaneous approach with the availability of various closure devices.
However, the diameter and calcification of the vessel represent major hurdles for using these devices. Further reduction
in the profile of stent-graft delivery device will expand the indication for percutaneous approaches to a great extent [32].
A graduated marker pigtail (4–5 Fr, 110 cm long) is introduced via the contralateral femoral artery. The stent-graft is then
navigated over a stiff guidewire and is placed at the desired position using fluoroscopy guided by several automated contrast
injections through the pigtail catheter. To avoid stent-graft misplacement, lowering of systolic blood pressure <80 mm Hg
by either drug or rapid pacing is desirable.
For TAD, primary tear occlusion should be the focus. The stent graft should be sized based on the diameter of the aorta
proximal to the entry tear, applying almost no oversizing. The technical challenge may be to cannulate the collapsed TL in
complicated dissection. TEE may be necessary to delineate the TL. Because of the self-expanding nature of the stent graft
and time required for remodeling process of the aorta, postdilation with balloon is not recommended. Ballooning has been
known to cause retrograde dissection and rupture of the dissection membrane [33]. The total length of the device must be
weighed against the risk of spinal cord ischemia. Procedural success is defined as sealing of primary entry tear (i.e., absence
of type Ia endoleak) and induction of FL thrombosis. The aim of the treatment is to overcome the complication of TAD and
it does not imply complete immediate FL thrombosis, which is a matter of time. It seems reasonable to accept continued
perfusion of the FL in the abdomen distal to stent graft site as long as there is no aortic dilatation [33].
The main prerequisites of TEVAR in TAA is the presence of 2 cm of proximal landing zone distal landing zones of
normal size and fairly straight aorta in order to assure a good seal and fixation of the graft. If more than one prosthesis is
implanted, the overlap between two elements should be more than 5 cm to avoid separation during follow-up, especially in
cases with tortuous and angulated anatomy. In case of proximal and distal landing zone diameter mismatch exceeding 4 cm,
the procedure should be completed by either using a tapered stent graft or two endoprosthesis of different diameters (the
smaller one deployed first followed by insertion the larger endoprosthesis to facilitate good sealing) [34]. The stent-graft
diameter should exceed the diameter of the landing zones by at least 10%–15% of the reference aortic diameter. Anatomic
constraints in the infrarenal aorta or the thoracoabdominal transition with excessive tortuosity may preclude advancement
of the endoprosthesis, which may be overcome using, in addition to a superstiff guidewire, a second protected stiff buddy
wire or a pull-through procedure via the brachial artery [33]. The outcome parameters of significance are survival and
aortic-related survival. The other outcome parameters would be persisting or newly developing endoleak, freedom from
intervention, or secondary OSR [33].
Stent Graft Selection
Selection of ideal endograft should be decided based on the morphological characteristics of the aorta to facilitate easy
and accurate deployment, permanent fixation, and long durability. The parameters include those of stent configuration,
material, fixation mechanism, sizes, delivery systems, tapered design, and radial force. Devices with or without proximal
uncovered struts and a tip-capture are available. Tip-capture reduces blood pressure or anatomy-dependent migration of
the prosthesis [33]. Proximal uncovered struts ensure enhancement of proximal fixation and adequate alignment of the
endograft.
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Preservation of Perfusion of Aortic Branches
Aortic pathologies involving major side branches pose a challenge for TEVAR. Implantation of a stent graft may result
in critical ischemia and organ dysfunction. Left subclavian artery (LSA) could be excluded by performing left common
carotid artery (LCCA) to LSA bypass or less commonly by transposing the LSA directly to LCCA. Catheter-based nonsurgical approaches include development of dedicated stent graft with fenestrations or branches for direct side branch access
and modifications of available interventional techniques to establish extra-anatomic side branch perfusion (“Chimney,”
Sandwich technique, etc.). These are still investigational and should not be endorsed [33].
Hybrid Procedure
Frozen elephant trunk technique involves conventional surgical repair of the ascending aorta and the arch combined with
open endograft stenting of the descending aorta in the period of circulatory arrest [35–37]. Rerouting of supraaortic branches
by transposition or bypass enables endovascular treatment of the arch and proximal descending aorta without cardiopulmonary bypass and hypothermic circulatory arrest [38].
Follow-Up
Currently CTA is recommended prior to discharge. Further follow-ups at 6 and 12 months is based on CTA, thereafter MRI/
CTA in addition to annual clinical follow-up should be encouraged. Lifelong clinical and morphological surveillance is
necessary after TEVAR as late treatment failure may develop [39].
COMPLICATIONS
Vacular, Procedure, and Stent Graft–Related Complications
Thrombosis, bleeding, retrograde aortic type A dissection, perforation of superstiff guidewire are common procedurerelated complications. One of the most devastating complications is retrograde type A dissection. Radial force of uncovered
struts, diagnosis of TAD, extensive oversizing, and balloon may be contributing factors [40]. The membrane rupture at the
distal end of the stent graft may occur in TAD.
Endoleaks
Endoleaks (Table 40.3) represent the most common complication of TEVAR of aortic pathology with a rate ranging from
4% to 24% [41]. Type I endoleaks are more serious and require expeditious intervention as there exist direct communication between the aneurysm sac and aortic blood flow [42]. Type II endoleaks are managed by watchful expectancy to detect
TABLE 40.3 Types of Endoleaks [43]
Type 1: Graft ends leak (inadequate seal)
l
1a: Proximal
l
1b: Distal
l
1c: Iliac occluder (plug)
Type II: Branch leaks (without attachment site connection)
l
2a: Single vessel
l
2b: Two vessels or more
Type III: Leak through a defect in graft fabric (mechanical failure of graft)
l
3a: Junctional separation of the modular components
l
3b: Fabric disruption (midgraft hole)
l
Minor (≤2 mm; e.g., suture hole)
l
Major (≥2 mm)
Type IV: Porous graft (30 days after graft placement)
Type V: Endotension
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aneurysmal expansion except for supra-aortic arteries. In these patients, coil embolization, plug occlusion, or surgical
ligation should be performed during or early post-TEVAR [33]. Type III endoleaks require endovascular therapy with new
endoprosthesis. Type IV and V endoleaks are no longer observed with more recent technology [43]. Type Ia (antegrade
perfusion of FL) and type II (perfusion of FL via overstenting of LSA) are important in TAD. The majority of the endoleaks
can be prevented by careful selection pertaining to landing zone length, use of multiple stents, overlapping stents, as well
as severe angulation and aortic calcification [44].
Brain Injury
Brain injury is a major complication linked to device manipulation, underlying stenting, and overstenting of one or more
great vessel. Stroke incidence can be reduced by aggressively maintaining antegrade cerebral perfusion through prior vascular transposition [28].
Spinal Cord Injury
Risk of paraplegia is increased with TEVAR if more than 10 intercostal pairs are sacrificed [45]. Factors influencing this
condition include prior abdominal aortic repair, extended length of thoracic aortic coverage, LSA coverage, hypogastric
artery interruption, emergency repair, and hypotension [33]. Predeployment subclavian transposition would be useful. In
high-risk cases, cerebrospinal fluid drainage via a lumbar drain, intercostal artery reimplantation, maintenance of normotension, and hypothermia have been suggested [34].
Aortoesophageal or Aortobronchial Fistulation
Fistulation after TEVAR is rare and is more commonly seen after acute aortic syndromes than elective procedure. Local
inflammation in the posterior mediastinum may contribute to this condition. Radical esophageal resection is the treatment
of choice [33].
CONCLUSION
TEVAR has revolutionized aortic medicine, enhancing the armamentarium of the interventional cardiologists in managing
acute or chronic thoracic disease. It has had a transformative impact and in view of reduced rate of morbidity and mortality, it might replace OSR in the treatment of traumatic AI and complicated type B TAD in near future as the technologies
continue to evolve. Even TEVAR is geared to compete with OMT in uncomplicated dissection because of the long-term
gains. It is not unreasonable to predict that TEVAR will be useful in some patients with type A dissection in the near future.
Amidst the plethora of good news and growing enthusiasm, multidisciplinary team approach is necessary for careful considerations regarding individual patient’s anatomic suitability and clinical appropriateness. As the technologies continue to
improve, it is anticipated that the limitations associated with TEVAR will decrease with development of smaller stent-graft
device (reducing outer diameter) increasing the conformability and trackability.
ABBREVIATIONS
FDP Fibrinogen-fibrin degradation product
FI Fusiform index
FL False lumen
TAD Thoracic aortic dissection
TL True lumen
ULP Ulcer-like hematoma
REFERENCES
[1] Volodos NL, Shekhanin VE, Karpovich IP, et al. A self-fixing synthetic blood vessel endoprosthesis. Vestn Khir Im I I Grek 1986;137:123–5.
[2] Dake MD, Miller DC, Semba CP, et al. Transluminal placement of endovascular stent-grafts for the treatment of descending thoracic aortic aneu-
rysms. N Engl J Med 1994;331:1729–34.
[3] Dake MD, Kato N, Mitchell RST, et al. Endovascular stent-graft placement for the treatment of acute aortic dissection. N Engl J Med
1999;340:1546–52.
Thoracic Endovascular Aortic Repair Chapter | 40 453
https://t.me/med1917
[4] Nienaber CA, Fattori R, Lund G, et al. Nonsurgical reconstruction of thoracic aortic dissection by stent-graft placement. N Engl J Med
1999;340:1539–45.
[5] Booher AM, Eagle KA. Diagnosis and management issues in thoracic aortic aneurysm. Am Heart J 2011;162:38–46.
[6] Isselbacher EM. Thoracic and abdominal aortic aneurysms. Circulation 2005;111:816–28.
[7] Rousseau H, Chabbert V, Maracher MA, et al. The importance of imaging assessment before endovascular repair of thoracic aorta. Eur J Vasc
Endovasc Surg 2009;38:408–21.
[8] Erbel R, Alfonso F, Boileau C, et al. Diagnosis and management of aortic dissection. Eur Heart J 2001;22:1642–81.
[9] Reeps C, Pelisek J, Bundschuh RA, et al. Imaging of acute and chronic aortic dissection by 18F-FDG PET/CT. J Nucl Med 2010;51:686–91.
[10] Schutz W, Gauss A, Meierhenrich R, et al. Transesophageal echocardiographic guidance of thoracic aortic stent-graft implantation. J Endovasc Ther
2002;9(Suppl. 2):II14–19.
[11] Koschyk DH, Meinertz T, Hofmann T, et al. Value of intravascular ultrasound for endovascular stent-graft placement in aortic dissection and aneu-
rysm. J Card Surg 2003;18:471–7.
[12] Eggebrecht H, Zenge M, Ladd ME, et al. Quick HH. In vitro evaluation of current thoracic aortic stent-grafts for real-time MR-guided placement.
J Endovasc Ther 2006;13:62–71.
[13] Fattori R, Nienaber CA, Rousseau H, et al. Results of endovascular repair of the thoracic aorta with the talent thoracic stent-graft: the talent thoracic
retrospective registry. J Thorac Cardiovasc Surg 2006;132:332.
[14] Umaña JP, Lai DT, Mitchell RS, et al. Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections?
J Thorac Cardiovasc Surg 2002;124:896–910.
[15] Brunkwall J, Kasprzak P, Verhoeven E, et al. Endovascular repair of acute uncomplicated aortic type B dissection promotes aortic remodelling: 1
year results of the ADSORB trial. Eur J Vasc Endovasc Surg 2014;48:285–91.
[16] Svensson LG, Kouchoukos NF, Miller DC, et al. Expert consensus document on the treatment of descending thoracic aortic disease using endovas-
cular stent grafts. Ann Thoracic Surg 2008;85:S1–41.
[17] Nienaber CA, Rousseau H, Eggebrecht H, et al. Randomized comparison of strategies for type B aortic dissection: the INvestigation of STEnt Grafts
in Aortic Dissection (INSTEAD) trial. Circulation 2009;120:2519–28.
[18] Nienaber CA, Kische S, Rousseau H, et al. For the INSTEAD-XL trial. Endovascular repair of type B aortic dissection: long-term results of the
randomized investigation of stent grafts in aortic dissection trial. Circ Cardiovasc Interv 2013;6:407–16.
[19] van Bogerijen GH, Tolenaar JL, Rampoldi V, et al. Predictors of aortic growth in uncomplicated type B aortic dissection. J Vasc Surg 2014;59:1134–43.
[20] Szeto WY, McGarvey M, Pochettino A, et al. Results of a new surgical paradigm: endovascular repair for acute complicated type B aortic dissection.
Ann Thorac Surg 2008;86:87–93.
[21] Criado FJ. Aortic dissection: A 250-year perspective. Texas Heart Institute Journal 2011;38:694–700.
[22] Nienaber CA, Kische S, Zeller T, et al. Provisional extension to induce complete attachment after stent graft placement in type aortic dissection: the
PETTICOAT concept. J Endovasc Ther 2006;13:738–46.
[23] Xiong J, Jiang B, Guo W, et al. Endovascular stent graft placement in patients with type B aortic dissection: a meta-analysis in China. J Thorac
Cardiovasc Surg 2009;138:865–72.
[24] Hiratzka LF, Bakris GL, Beckman JA, et al. American College of Cardiology Foundation/American Heart Association Task Force on Practice
Guidelines; American Association for Thoracic Surgery; American College of Radiology; American Stroke Association; Society of Cardiovascular
Anesthesiologists; Society for Cardiovascular Angiography and Interventions; Society of Interventional Radiology; Society of Thoracic Surgeons;
Society for Vascular Medicine. ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM guidelines for the diagnosis and management of patients
with Thoracic Aortic Disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice
Guidelines, American Association for Thoracic Surgery, American College of Radiology, American Stroke Association, Society of Cardiovascular
Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons,
and Society for Vascular Medicine. Circulation 2010;121:e266–369.
[25] Moreno-Cabral CE, Miller DC, Mitchell RS, et al. Degenerative and atherosclerostic aneurysms of the thoracic aorta: determinants of early and late
surgical outcome. J Thorac Cardiovasc Surg 1984;88:1020–32.
[26] Svensson LG, Crawford ES, Hess KR, et al. Experience with 1509 patients undergoing thoracoabdominal aortic operations. J Vasc Surg
1993;17:357–68.
[27] Czerny M, Funovics M, Sodeck G, et al. Long-term results of thoracic endovascular aortic repair in atherosclerotic aneurysms involving the descend-
ing aorta. J Thorac Cardiovasc Surg 2010;140:S179–84.
[28] Gottardi R, Funovics M, Eggers N, et al. Supra-aortic transposition for combined vascular and endovascular repair of aortic arch pathology. Ann
Thorac Surg 2008;86:1524–9.
[29] Fattori R, Napoli G, Lovato L, et al. Indications for, timing of, and results of catheter-based treatment of traumatic injury to the aorta. Am J
Roentgenol 2002;179:603–9.
[30] Scheinert D, Krankenberg H, Schmidt A, et al. Endoluminal stent-graft placement for acute rupture of the descending thoracic aorta. Eur Heart J
2004;25:694–700.
[31] Dake MD, White RA, Diethrich EB, Society for Vascular Surgery Outcomes Committee, et al. Report on endograft management of traumatic tho-
racic aortic transections at 30 days and 1 year from a multidisciplinary subcommittee of the Society for Vascular Surgery Outcomes Committee. J
Vasc Surg 2011;53:1091–6.
[32] Lonn L, Larzon T, Van Den Berg JC. From puncture to closure of the common femoral artery in endovascular aortic repair. J Cardiovasc Surg
(Torino) 2010;51:791–8.
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https://t.me/med1917
[33] Grabenwoger M, Alfonso F, Bachet J, et al. Thoracic Endovascular Aortic Repair (TEVAR) for the treatment of aortic diseases: a position statement from
the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society of Cardiology (ESC), in collaboration with the European
Association of Percutaneous Cardiovascular Interventions (EAPCI). European Heart Journal 2012. http://dx.doi.org/10.1093/eurheartj/ehs074.
[34] Fanelli F, Dake MD. Standard of practice for the endovascular treatment of thoracic aortic aneurysms and type B dissections. Cardiovasc Intervent
Radiol 2009;32:849–60.
[35] Chavan A, Karck M, Hagl C, et al. Hybrid endograft for one-step treatment of multisegment disease of the thoracic aorta. J Vasc Interv Radiol
2005;16:823–9.
[36] Gorlitzer M, Weiss G, Thalmann M, et al. Combined surgical and endovascular repair of complex aortic pathologies with a new hybrid prosthesis.
Ann Thorac Surg 2007;84:1971–6.
[37] Jakob H, Tsagakis K, Pacini D, et al. The International E-vita Open Registry: data sets of 274 patients. J Cardiovasc Surg (Torino) 2011;52:717–23.
[38] Weigang E, Parker J, Czerny M, et al. Endovascular aortic arch repair after aortic arch de-branching. Ann Thorac Surg 2009;87:603–7.
[39] Dumfarth J, Michel M, Schmidli J, et al. Mechanisms of failure and outcome of secondary surgical interventions after thoracic endovascular aortic
repair (TEVAR). Ann Thorac Surg 2011;91:1141–6.
[40] Dong ZH, Fu WG, Wang YQ, et al. Retrograde type A aortic dissection after endovascular stent graft placement for treatment of type B dissection.
Circulation 2009;119:735–41.
[41] Nienaber CA, Kische S, Ince H. Thoracic aortic stent-graft devices: problems, failure modes, and applicability. Semin Vasc Surg 2009;20:81–9.
[42] Buth J, Harris PL, van Marrewijk C, et al. The significance and management of different types of endoleaks. Semin Vasc Surg 2003;16:95–102.
[43] Turina MI, Shennib H, Dunning J, EACTS/ESCVS Committee, et al. EACTS/ESCVS best practice guidelines for reporting treatment results in the
thoracic aorta. Eur J Cardiothorac Surg 2009;35:927–30.
[44] Dumfarth J, Michel M, Schmidli J, et al. Mechanisms of failure and outcome of secondary surgical interventions after thoracic endovascular aortic
repair (TEVAR). Ann Thorac Surg 2011;91:1141–6.
[45] Cheung AT, Pochettino A, McGarvey ML, et al. Strategies to manage paraplegia risk after endovascular stent repair of descending thoracic aortic
aneurysms. Ann Thor Cardiovasc Surg 2005;80:1280–9.
Chapter 41
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Transcatheter Aortic Valve Implantation
Hardy Baumbach, Kristina Wachter, Christian Rustenbach, Adrian Ursulescu, Ulrich F.W. Franke
Robert Bosch Hospital, Stuttgart, Germany
Chapter Outline
Historical Development 455
Patient Selection 455
Indications for TAVI 456
Surgical Techniques and Access Sites 456
Prosthesis 457
HISTORICAL DEVELOPMENT
Aortic valve stenosis is the most common valvular heart disease, with about one out of eight people aged 75 years and older
having aortic stenosis with 3.4% suffering from severe aortic valve stenosis [1]. In symptomatic patients, surgical aortic
valve replacement (SAVR) is the gold standard to treat these patients and is therefore recommended in the guidelines [2].
However, a systematic metaanalysis reported that 40.5% of elderly patients with symptomatic severe aortic valve stenosis
did not undergo SAVR because of high or prohibitive surgical risk [1]. For these patients, transcatheter aortic valve implantation (TAVI) presents an alternative.
The first successful in-human TAVI was performed by Alain Cribier in 2002 [3]. The first patient was a 57-year-old
man with calcific aortic stenosis, cardiogenic shock, subacute leg ischemia, and several other comorbidities, resulting in a prohibitive surgical risk. The bovine balloon-expandable valve (Percutaneous Valve Technologies, Inc.) was
implanted via an antegrade and transseptal approach from the right femoral vein. Before this, percutaneous catheterbased systems for the treatment of valvular heart disease have been studied in animal models for years [4–6].
The first bovine self-expanding valve prosthesis was implanted in 2004 in a 73-year-old woman with severe symptomatic aortic valve stenosis, not acceptable for conventional SAVR [7]. The approach was retrograde via the common iliac
artery and a temporary extracorporeal circulation was applied to unload the left ventricle during the actual stent expansion.
After this, the first balloon-expandable valve, Edwards SAPIEN (Edwards Lifesciences, Irvine, CA, USA) and the first
self-expandable valve, CoreValve (Medtronic, Irvine, CA, USA), were commercially approved in Europe in 2007 and in
the United States in 2011 and 2014, respectively.
Complications 460
Updates and Future Developments 460
References 461
Further Reading 462
PATIENT SELECTION
Risk scores play an important role in patient selection process. There are several risk scores, calculating the estimated
perioperative mortality of cardiovascular patients. The logistic EuroSCORE, EuroSCORE II (European System for Cardiac
Operative Risk Evaluation) [8], and the STS PROM (Society of Thoracic Surgeons–Predicted Risk of Mortality) [9] have
been demonstrated to be the most appropriate risk scores in cardiovascular surgery. However, the logistic EuroSCORE has
been identified to overestimate the perioperative mortality and the STS score is seen to be superior in the TAVI patient cohort
[10]. These models could only provide assistance in decision for finding the suitable surgical treatment. Comorbidities,
frailty, and the patient’s opinion are other very important factors in the decision-making process. The Katz Index is a score
to evaluate activities of daily living and is used as a measurement of the patients’ functional status and is therefore a measurement for frailty. It should be incorporated into preoperative risk assessment because a low Katz Index has been shown
to be a powerful predictor of negative early and late outcome after TAVI [11]. However, there is no specific TAVI risk score,
yet. As recommended in the guidelines, a heart team should always be involved to provide optimal patient care.
New Approaches to Aortic Diseases from Valve to Abdominal Bifurcation. http://dx.doi.org/10.1016/B978-0-12-809979-7.00041-9
Copyright © 2018 Elsevier Inc. All rights reserved.
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INDICATIONS FOR TAVI
According to the American College of Cardiology/American Heart Association Task Force guidelines of 2014, TAVI is
reasonable in patients who meet an indication for aortic valve replacement (symptomatic severe aortic stenosis) who
have a prohibitive or high risk for surgical AVR (STS PROM >10) and a predicted post-TAVI survival greater than
12 months (Class I and IIa, Level of Evidence B). In both instances, a heart team, consisting of an integrated, multidisciplinary group of interventional cardiologist, cardiac anesthetist, and cardiac surgeon, should collaborate to provide
optimal patient care [2].
In a randomized trial (PARTNER IB) comparing TAVI with standard medical therapy (including balloon valvuloplasty) in a patient population that is not suitable for SAVR (STS PROM: TAVI cohort 11.2% and standard therapy
12.1%), TAVI could demonstrate superior survival with less cardiac symptoms (rate of death at 1 year for TAVI 30.7%
vs. standard therapy 50.7%; P < .001) [12]. This supports the concept that standard medical therapy is inferior to surgical or interventional therapy in patients with symptomatic severe aortic valve stenosis and that even high-risk patients
should not be left untreated. A subsequent trial comparing surgical AVR with TAVI in high-risk patients (PARTNER
IA; STS PROM: TAVI cohort 11.8% and SAVR cohort 11.7%) displayed comparable survival after 12 months (death
at 1 year after TAVI 24.2% vs. SAVR 26.8%; P = .44), indicating that TAVI is an alternative to surgical valve replacement in a well-chosen, high-risk subgroup of patients with aortic valve stenosis [13].
As the indications for TAVI have gradually been expanded during the past few years, discussion has begun to
consider if TAVI should be a therapy option in patients with lower perioperative risk. Several studies examine the outcome after TAVI in intermediate- or low-risk patient cohorts. These studies could demonstrate low 30-day mortality
rates of 0.9%–7.8% in intermediate-risk patients [14–16] and 1.4%–2.4% in low-risk patients [17,18]. In a randomized, multicenter trial, comparing TAVI and SAVR in patients with intermediate risk (STS PROM 5.8%), both procedures showed similar results in terms of death or disabling stroke, proving the noninferiority of TAVI procedure [19].
Recently, the new-generation device CoreValve Evolut R has been approved as the first device for use in intermediaterisk patients in Europe. However, the guidelines have not expanded the indications by this patient population by now.
One important reason is that there are no data on long-term durability of TAVI prostheses available yet, as there is for
prostheses used in conventional SAVR. Overall, several studies could not demonstrate any difference in 30-day and
midterm mortality between patients at lower surgical risk undergoing TAVI or SAVR [16,17,19], thus not justifying
to perform TAVI in this patient cohort.
SURGICAL TECHNIQUES AND ACCESS SITES
There are several approaches for transcatheter aortic valve replacement, combining different technical aspects, advantages,
and contraindications.
The transfemoral approach is the most common access for TAVI, with approximately 70%–80% of TAVI procedures
performed transfemorally [20]. The common femoral artery is punctured and the aortic valve passed retrogradely. An
important advantage is that this method could be performed percutaneously, without any surgical intervention and in local
anesthesia [21]. Contraindications for this technique are peripheral vascular disease or a diseased aorta. The femoral access
is additionally limited to a smaller size of the delivery system. In recent trials, transfemoral TAVI is associated with low
30-day and 1-year mortality rates of 3.0% and 10.0%, respectively [19].
The transapical approach is achieved through an anterolateral minithoracotomy and direct antegrade access to
the left ventricle and the native aortic valve [22]. Femoral arterial and venous access wires are additionally required.
The valve implantation is performed with minimal manipulation of the ascending aorta and aortic arch, thus reducing
the risk of stroke compared with the transfemoral implantation. The transapical technique is therefore also possible
in patients with severe peripheral vascular disease. Additionally, the size of the delivery system is almost not limited. Possible disadvantages are the required minithoracotomy, especially in patients with severe chronic obstructive
pulmonary disease, postoperative pain, the need of general anesthesia, and possible myocardial injury. Although
patients undergoing transapical access are often at higher perioperative risk (more peripheral vascular disease, higher
risk scores) and some studies report higher mortality rates compared with the transfemoral access [19], there is also
evidence of comparable operative and long-term mortality rates compared with the transfemoral procedures [23].
Therefore, it is a valuable alternative for patients unsuitable for transfemoral TAVI.
A further retrograde access to the aortic valve is the transaortic approach [24]. It is used in patients who are unsuitable for transfemoral access because of peripheral vascular disease, and also unsuitable for transapical access because
of respiratory disease or decreased left ventricular function [25]. The ascending aorta is accessed via a partial upper
hemisternotomy or a right anterior thoracotomy. The puncture is also restricted in patients with aortic calcification;
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