Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3734_Библиотеки_им_академика_М_И_Перельмана
.pdf
264
https://t.me/med1917
M. Kreibich and F. Beyersdorf
The Endovascular Valve-Carrying Conduit
The concept of a transapically-implantable, endovascular, valve–carrying conduit
for treating aortic valve and ascending aortic pathologies was rst introduced by
Rylski etal. [21]. The endo-conduit consists of a proximal transcatheter aortic valve
connected to an uncovered portion of a covered stent-graft. This device is capable of
1. closing a primary entry tear in the ascending aorta,
2. ensuring coronary and cerebral perfusion,
3. stabilizing the distal aorta, initiating true lumen expansion and ensuring distal
malperfusion,
4. treating aortic regurgitation, and
5. draining any pericardial effusion via a transapical approach
While conventional TEVAR with a straight tube graft requires two landing zones
to afx and seal the graft durably, the valve-carrying conduit would encompass a
third, proximal landing zone within the aortic annulus ensuring durable and stable
anchorage of the entire device (Fig.1). Hence, the proximal and distal stent-graft
landing zones need not sustain the stent-graft itself, it merely needs to seal it off.
Thus, oversizing of the conventional stent-graft landing zones proximally and distally becomes unnecessary, and the landing zones can potentially be even shorter.
The latter would enlarge the pool of patients even more.
Individualization is a cornerstone of the conduit because the size of the catheter
valve and stent-graft portion can be specically selected to ideally accommodate the
patient’s unique anatomy and their specic entry-tear location within the ascending
aorta. In a large feasibility study [9], our group was recently able to demonstrate that
over two-thirds of all patients suffering an acute type A aortic dissection are potential candidates for the endovascular valve-carrying conduit to stabilize the proximal
aorta and close any entry tear within the ascending aorta. Our investigation also
showed that just eight different stent-graft lengths would sufce to treat these
patients, but also that most of these patients would require short, tapered stentgrafts. Also, 7% of patients would require broader transcatheter aortic valve sizes [9].
A one-stage and a two-stage clinical scenario for implanting the endovascular
valve-carrying conduit seem feasible. In the one-stage scenario, the conduit could
be used to stabilize the ascending aorta in patients without malperfusion but carrying a high perioperative risk. Frail patients are potential candidates for this onestage treatment. In the two-stage scenario, the conduit could be the rst-step
treatment to resolve distal malperfusion by re-expanding the true lumen and proximally stabilizing the dissected ascending aorta. Once the patient has stabilized and
both shock and malperfusion have resolved, a stable patient could undergo conventional surgery in the second step with signicantly better postoperative outcome
prospects. This scenario is comparable to the Emory group’s TEVAR rst strategy,
but would offer these patients the substantial benet of proximal stabilization [22,
23] (Figs.2 and 3).
e
free coronary perfusion
free supra-aortic perfusion
Endovascular Treatment ofType AAortic Dissections
https://t.me/med1917
265
tapered stent-graft
catheter valv
Fig. 1 The endovascular valve-carrying conduit consists of a transcatheter aortic valve connected
to an uncovered portion of a covered stent-graft. Three landing zones can be generated by the
device: (1) the aortic valve annulus for stable anchorage of the device, (2) a proximal sealing zone
at the level of the sinotubular junction, and (3) a distal sealing zone at the level of the distal ascending aorta before the brachiocephalic trunk’s takeoff. Individualization is the conduit’s fundamental
advantage, since the catheter valve size and stent-graft portion can be selected individually to
accommodate the patient’s unique anatomy, and the two components can be connected shortly
before implantation by a suture. Free coronary and supra-aortic perfusion is thus ensured
266
https://t.me/med1917
Fig. 2 The endovascular
valve-carrying conduit
before implantation. The
proximal transcatheter
aortic valve with proximal
landing zone 1 for
anchorage is connected to
the covered stent-graft with
the two sealing zones (2
and 3)
M. Kreibich and F. Beyersdorf
Fig. 3 Representative
radiographic image of in
vivo implantation of the
endovascular valvecarrying conduits in a pig
model
Endovascular Treatment ofType AAortic Dissections
https://t.me/med1917
267
Conclusion
Ascending aortic TEVAR currently remains conned to the purview of specialized
aortic centers treating carefully-selected patients with favorable anatomy and/or a
localized pathology. Physiologic, anatomic, medical, and technical problems limit
the routine application of TEVAR in the ascending aorta, particularly in patients
suffering from type A aortic dissection. The provision of an endovascular valvecarrying conduit raises the potential number of patients eligible for endovascular
treatment considerably, and may help to signicantly reduce the morbidity and mortality of patients with type A aortic dissections.
Disclosures/conict of interest No disclosures/conict of interest for any author.
Funding Institutional funding.
References
1. Dumfarth J, Peterss S, Luehr M, Etz CD, Schachner T, Koer M, etal. Acute type A dissection
in octogenarians: does emergency surgery impact in-hospital outcome or long-term survival?
Eur J Cardiothorac Surg. 2017;51:472–7.
2. Kreibich M, Rylski B, Czerny M, Siepe M, Beyersdorf F, Chen Z, etal. Inuence of age and
the burden of ischemic injury on the outcome of type A aortic dissection repair. Ann Thorac
Surg. 2019;108:1391–7.
3. Kreibich M, Bavaria JE, Branchetti E, Brown CR, Chen Z, Khurshan F, etal. Management of
patients with coronary artery malperfusion secondary to type A aortic dissection. Ann Thorac
Surg. 2019;107:1174–80.
4. Kreibich M, Chen Z, Rylski B, Bavaria JE, Brown CR, Branchetti E, etal. Outcome after
aortic, axillary, or femoral cannulation for acute type A aortic dissection. J Thorac Cardiovasc
Surg. 2019;158:27–34. e9
5. Bavaria JE, Pochettino A, Brinster DR, Gorman RC, McGarvey ML, Gorman JH, etal. New
paradigms and improved results for the surgical treatment of acute type A dissection. Ann
Surg. 2001;234:336–42. discussion 42–3
6. Roselli EE, Hasan SM, Idrees JJ, Aftab M, Eagleton MJ, Menon V, etal. Inoperable patients
with acute type A dissection: are they candidates for endovascular repair? Interact Cardiovasc
Thorac Surg. 2017;25:582–8.
7. Brown CR, Chen Z, Khurshan F, Kreibich M, Bavaria J, Groeneveld P, etal. Outcomes after
thoracic endovascular aortic repair in patients with chronic kidney disease in the Medicare
population. J Thorac Cardiovasc Surg. 2020;159(2):402–13. https://doi.org/10.1016/j.
jtcvs.2019.01.118.
8. Kreibich M, Rylski B, Kondov S, Morlock J, Scheumann J, Kari F, etal. Endovascular treat-
ment of acute Type A aortic dissection—the Endo Bentall approach. J Vis Surg. 2018;4:69.
9. Kreibich M, Soekeland T, Beyersdorf F, Bavaria JE, Schrofel H, Czerny M, etal. Anatomic
feasibility of an endovascular valve-carrying conduit for the treatment of type A aortic dissection. J Thorac Cardiovasc Surg. 2019;157:26–34 e1.
10. Jin S, Oshinski J, Giddens DP.Effects of wall motion and compliance on ow patterns in the
ascending aorta. J Biomech Eng. 2003;125:347–54.
268
https://t.me/med1917
11. Beller CJ, Labrosse MR, Thubrikar MJ, Robicsek F.Role of aortic root motion in the patho-
genesis of aortic dissection. Circulation. 2004;109:763–9.
12. Kreibich M, Bunte D, Berger T, Votsch A, Rylski B, Krombholz-Reindl P, etal. Distal stent-
graft- induced new entries following the frozen elephant trunk procedure. Ann Thorac Surg.
2020;110(4):1271–9.
13. van Bakel TMJ, Arthurs CJ, Nauta FJH, Eagle KA, van Herwaarden JA, Moll FL, etal. Cardiac
remodelling following thoracic endovascular aortic repair for descending aortic aneurysms.
Eur J Cardiothorac Surg. 2019;55:1061–70.
14. Kreibich M, Morlock J, Beyersdorf F, Berger T, Allweier S, Kondov S, etal. Decreased biven-
tricular function following thoracic endovascular aortic repair. Interact Cardiovasc Thorac
Surg. 2020;1(30):600–4.
15. Grabenwoger M, Alfonso F, Bachet J, Bonser R, Czerny M, Eggebrecht H, etal. 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). Eur Heart J. 2012;33:1558–63.
16. Huang C, Zhou M, Liu Z, Huang D, Ran F, Wang W, etal. Computed tomography-based study
exploring the feasibility of endovascular treatment of type A aortic dissection in the Chinese
population. J Endovasc Ther. 2014;21:707–13.
17. Moon MC, Greenberg RK, Morales JP, Martin Z, Lu Q, Dowdall JF, et al. Computed
tomographyfor endovascular candidacy. J Vasc Surg. 2011;53:942–9.
18. Rylski B, Desjardins B, Moser W, Bavaria JE, Milewski RK.Gender-related changes in aortic
geometry throughout life. Eur J Cardiothorac Surg. 2014;45:805–11.
19. Kreibich M, Rylski B, Czerny M, Pingpoh C, Siepe M, Beyersdorf F, etal. Type A aortic dissec-
tion in patients with bicuspid aortic valve aortopathy. Ann Thorac Surg. 2020;109(1):94–100.
20. Berezowski M, Morlock J, Beyersdorf F, Jasinski M, Plonek T, Siepe M, etal. Inaccurate aor-
tic stent graft deployment in the distal landing zone: incidence, reasons and consequences. Eur
J Cardiothorac Surg. 2018;53:1158–64.
21. Rylski B, Szeto WY, Bavaria JE, Branchetti E, Moser W, Milewski RK. Development of a
single endovascular device for aortic valve replacement and ascending aortic repair. J Card
Surg. 2014;29:371–6.
22. Leshnower BG, Keeling WB, Duwayri YM, Jordan WD Jr, Chen EP.The “thoracic endovascu-
lar aortic repair-rst” strategy for acute type A dissection with mesenteric malperfusion: Initial
results compared with conventional algorithms. J Thorac Cardiovasc Surg. 2019;158:1516–24.
23. Leshnower BG, Veeraswamy RK, Duwayri YM, Chen EP.The “TEVAR-rst” approach to
DeBakey I aortic dissection with mesenteric malperfusion. Ann Thorac Surg. 2014;97:693–6.
based anatomic characterization of proximal aortic dissection with consideration
https://doi.org/10.1016/j.athoracsur.2020.02.017.
M. Kreibich and F. Beyersdorf
Valve Sparing Aortic Root Replacement
https://t.me/med1917
forAortic Valve Insufciency inType
AAortic Dissection
EltayebMohamedAhmed andEdwardP.Chen
Introduction
Type A acute aortic dissection (TAAAD) is a surgical emergency that is rapidly fatal
if left untreated. The international registry of acute aortic dissection (IRAD) reported
an improvement in surgical outcome, as mortality decreased from 25 to 18% over
17years since its inception. Furthermore, contemporary series reported a mortality
as low as 5% [1–3].
The mortality of TAAAD is determined by preoperative risk factors, such as
malperfusion syndrome, renal impairment, or preoperative rupture [4, 5]. Therefore,
an operation that avoids a high-risk reintervention, and that is not associated with an
increase in immediate risk is optimal. Aortic root replacement, when required to
completely resect the proximal extent of the dissection, is associated with excellent
event-free survival and reoperation rates [6–8]. In fact, several series reported that
replacement of the aortic root in patients with TAAAD is not associated with an
increase in perioperative morbidity or mortality [5, 9, 10]. Furthermore, there is
evidence to show that root replacement decreases the need for reintervention, as
shown in a propensity matched cohort where the freedom from reintervention was
signicantly higher in the root replacement group 98 vs. 86% at 7 years [11].
Surgical options for aortic root replacement can be performed using a composite
valve conduit or a valve sparing technique (VSRR).
In this chapter we will discuss the indications for aortic root replacement in
TAAAD, valve sparing aortic root replacement (VSRR) in TAAAD, the technical
details of VSRR in TAAAD, and the result of valve conserving root surgery.
E. M. Ahmed
Bristol Royal Inrmary, Bristol, UK
E. P. Chen (
Section of Surgical Disciplines, Division of Cardiovascular and Thoracic Surgery,
Duke University Medical Center, Durham, NC, USA
e-mail: edward.p.chen@duke.edu
J. S. Coselli et al. (eds.), Aortic Dissection and Acute Aortic Syndromes,
https://doi.org/10.1007/978-3-030-66668-2_19
*)
269© Springer Nature Switzerland AG 2021
270
https://t.me/med1917
E. M. Ahmed and E. P. Chen
Indications forAortic Root Replacement inTAAAD
Replacement of the aortic root is indicated in patients with an aortic root diameter≥5.5cm, a diameter of 4.0–5.0cm in patients with concomitant risk factors for
rupture or dissection, or a simultaneously indicated valve or ascending aortic surgery [12, 13]. While these indications are well established in the elective setting,
they are also applied to patients with TAAAD.In patients with aortic dissection the
American Heart Association (AHA) recommended root replacement in patients
with extensive destruction of the aortic root or root dilatation [
degree of destruction or dilatation is not quantied and is an area of debate over
whether root replacement is required in TAAAD.Therefore, the decision to replace
the root is often based on an assessment of the risk of extensive repair against the
possibility of a complicated redo surgery in the future (Fig.1) [15].
Following supracomissural repair of TAAAD, the aortic root continues to enlarge
at a rate 0.50–0.60mm/year [16]. Furthermore, a substantial proportion of patients
operated for TAAAD will require a reintervention, the freedom from reintervention
is in the range 80–30% at 10years [5, 17]. Conversely, adding a root replacement to
an already high-risk operation does increase the risk of the operation as shown in the
University of Pennsylvania study, the mortality of aortic root replacement was
almost three times higher than supracomissural repair in patients with TAAAD [18,
19]. Therefore, it is important to identify risk factors for reoperation to enable the
surgeon to balance the risk of a complex redo procedure against an aggressive index
operation in TAAAD.
Several authors investigated the risk factors for reoperation following TAAAD
repair. Young-age has been identied as a risk factor for reoperation by several
groups [19, 20]. In a study of young patients, under the age of 50, the reoperation
rate following TAAAD was 24%. In the same cohort 44% of patients who had a
supracomissural replacement required a root procedure [19, 21, 22]. Kirsch et al.
studied 160 patients who underwent repair of TAAAD; the freedom from
12, 14]. However, the
Fig. 1 A 61-year-old male
patient who had
supracomissural repair of
TAAAD presenting with a
pseudoaneurysm 1 year
following initial repair
ab
Valve Sparing Aortic Root Replacement for Aortic Valve Insufciency in Type A Aortic…
https://t.me/med1917
271
reoperation at 10years was 60%, and they identied severe preoperative AI as a
predictor for proximal reoperation, RR 3.6 (95% CI 1.44–9.77) [7]. Certainly,
severe AI and root aneurysm are among the commonest indications for reoperation
following TAAD repair [23].
Patients with connective tissue disease are at a great risk of requiring a reintervention. In the Nordic Consortium for Acute Aortic Dissection Type A (NORCAAD)
study, the risk of reoperation was ve times higher in patients with connective tissue
disease [24]. A cohort study of over 500 patients, identied Marfan syndrome as a
risk factor for reintervention (OR 4.68 95% CI 1.6–13.7) [25]. We believe, among
other groups, that limited ascending repair without root replacement will almost
certainly result in the need for a root reintervention in this cohort of patients [26]. It
must be emphasized that often the diagnosis of Marfan syndrome is made after
presentation with TAAAD.Therefore, a high index of suspicion is needed particularly in the young [19].
In addition to hemodynamic characteristics of the aortic valve and the patients’
genetic risk prole, certain anatomical features of the dissection ap and the aortic
root are associated with a pronounced increase in the risk of a reintervention. The
preoperative root diameter, number of commissural detachment, and dissection ap
extension into the root are anatomical features that should be recognized and persuade the surgeon to take an aggressive approach to the aortic root in patients with
TAAAD (Fig.2) [27, 28].
The controversy, whether the root should be replaced or not, stems from the fact
that high rates of reintervention and the risk factors for reintervention have not been
universally identied and agreed upon among investigators. The NORCAAD, for
example, reported a reoperation rate of 5% at 8years, most of the reoperations were
in the form of a root replacement; however, the mean follow-up was 3.3years, and
25% of patients in the cohort had a root replacement [24]. Mayo clinic series had a
freedom from reoperation at 91% and 79% at 10 and 20years respectively. While
no predictive factors for reoperation were identied; yet 70% of reoperations were
for aortic root dilatation or aortic insufciency [5]. Low reoperation rates have been
reported by other groups in smaller studies [8, 18, 19, 29].
Fig. 2 Preoperative CTA demonstrating a dilated aortic root with the dissection ap extending
into the aortic root (a) and the ascending aorta (b)
272
https://t.me/med1917
The limitations of the evidence available are related to the fact that most studies
evaluating long term outcomes of TAAAD patients have a small number of patients,
retrospective in nature, single centre, and have a short follow-up. Therefore, a large
cohort of TAAAD patients with standardised follow-up is needed to enable the surgical community and patients make an informed decision of the choice of surgery in
this fatal disease.
At our institution, we perform root replacement if the tear is in the aortic root, the
root is dilated >4.5cm in diameter, and in patients with suspected connective tissue
disease. The IRAD reported a similar strategy of selective root with no difference in
outcome between the supracomissural repair group and the root replacement group.
In our experience, the outcome of VSRR in the hemodynamically unstable patients
and patients with malperfusion syndrome is unfavourable. However, other groups
did not preclude patients from a VSRR approach because of haemodynamic instability [9]. Halstead reported excellent results with a similar aggressive strategy
towards the root [8]. We also believe that the surgeon’s experience should be considered before recommending a liberal root replacement strategy in patients with
TAAAD [9, 30, 31].
E. M. Ahmed and E. P. Chen
VSRR inTAAAD
Bentall and De Bono used a Starr valve and a Teon graft in their technique of composite valve conduit aortic root replacement with reimplantation of the coronary
arteries [32]. The technique was modied by Cabrol, as the two ends of an 8mm
Dacron graft were anastomosed to the coronary ostia, the graft is subsequently anastomosed sided-to-side to the aortic prosthesis [33]. The early mortality in Cabrol
series, a third of which had aortic dissection, was an outstanding 4% [34].
The prosthetic valve component is the main limitation of the Bentall procedure.
Mechanical valves offer better durability, particularly in young patients, in comparison with bioprosthesis. The durability of mechanical prosthesis is offset by the risk
of anticoagulation, thromboembolic events and valve thrombosis. Bouhout and
associates reported survival, freedom from reoperation, and freedom from signicant bleeding of 87%, 82%, and 90% respectively at 10years in young patients. A
meta-analysis of the Bentall procedure, 7629 patients included, reported an annual
linearized risk of 2% for mortality, 0.77% thromboembolic events, and 2.66% of
valve related adverse events [35].
The risk of structural valve degeneration of bioprosthesis is of a considerable
importance when a bio-Bentall is contemplated. Reports of freedom from structural valve degeneration of modern bioprosthesis are limited by short follow-up
[36]. In a UK-based registry, the results of biological AVR were not encouraging
with a freedom from reintervention or death of 47% at 10years [37]. The AVR
data is pertinent to aortic root replacement using the Bentall technique, and clearly
the long-term results of prosthetic valve replacement are suboptimal. It is logical
that avoiding the adverse implications of a prosthetic valve, if possible, may result
Valve Sparing Aortic Root Replacement for Aortic Valve Insufciency in Type A Aortic…
https://t.me/med1917
in an improved survival and quality of life in patients undergoing aortic root
replacement [38, 39].
Sir Magdi Yacoub recognized in a cohort of patients with aortic insufciency and
aortic root aneurysm with normal cusps morphology that it was feasible to repair the
aortic root, restore the aortic valve hemodynamics, and preserve native valve function. In Yacoub’s remodelling technique, the aortic sinuses are excised, leaving a
rim of 3mm, the coronary ostia are isolated with a small aortic rim surrounding
them (coronary button), and a tube graft, fashioned into three tongues, is sutured to
the residual wall of the aortic root; subsequently, the coronary buttons are attached
to the tube graft [40, 41]. The remodelling method proved to deliver durable aortic
valve repair in selected patients [42]. A comparison between the results of remodelling in patients with type A aortic dissection and those with aneurysm revealed a
longer bypass time, longer ICU stay, and a mortality of 19% in line with the average
mortality in the IRAD with no difference in the reoperation rate or incidence of
AI [43].
Tirone David and Chris Feindel, in 1992, introduced the reimplantation procedure, and reported their experience of ten patients with annuloaortic ectasia; four
patients had aortic dissection in the series. In the reimplantation technique, the aortic valve is implanted within a tube graft that is anchored to the VAJ.In their series,
there were no deaths, and one patient required reoperation for aortic insufciency [44].
The advantage of the remodelling is that it preserves the inter-leaet triangles,
which may facilitate the dynamic nature of the native aortic root. Indeed, in-vivo
studies demonstrated superior hemodynamics with remodelling in comparison with
reimplantation [45]. However, a major limitation of the remodelling procedure is
that it doesn’t provide external stabilization of the VAJ, which is a potential cause
for recurrence of AI and a source for a higher failure rate in patients with TAAAD
[46–48]. However, the reimplantation requires more extensive dissection of the aortic root, takes longer, and potentially technically more demanding [42, 46]. Emanuel
Lansac addressed stabilisation of the VAJ by adding an expansible ring in the subvalvular plane [49, 50]. The early results of remodelling in addition to subvalvular
ring implantation demonstrated a reduction in the rate of reoperations and intraoperative conversion to prosthetic valve replacement [50]. Several modications of the
remodelling were developed, but most remain single-centre and reported in a small
number of patients. Dr. C Miller group advocate a conservative partial root replacement, Uni-Yacoub or Bi-Yacoub repair, in selected patients [51].
273
Technical Aspects ofValve Sparing Root Replacement
inTAAAD
The aim of VSRR is to provide durable repair with a low reintervention rate on the
aortic valve. At the authors’ institution, our procedure of choice is the reimplantation technique. Stabilization of the VAJ with a ring in combination with remodelling
Соседние файлы в папке Библиотека им академика М.И. Перельмана