2. Introduction
• Different aortic segments may had
aneurysm/dissection at the same time or a second
can develop later in a patient previously operated on
for the same pathology.
• Complex aortic pathology, involving the aortic arch
and proximal descending aorta, has until the 1990s
been approached in one or two stages
• Either one or two stages, had a drawback
J Endovasc Ther. 2012 Jun;9
16. Ann Cardiothorac Surg 2013;2(5):629-630
Ann Cardiothorac Surg 2013;2(5):633-639
Hybrid arch techniques provide a safe alternative to open repair with
acceptable short- and mid-term results.
However, stroke and mortality rates remain noteworthy. Future
prospective trials that compare open conventional techniques with the
hybrid method or the entirely endovascular method are needed.
25. When revascularization of the LSA is strongly
recommended :
•Occluded or severely stenosed right VA
•Clearly dominant left VA
•Discontinuity of the vertebrobasilar system
•Presence of a patent left internal mammary artery to
coronary artery by-pass graft
•A functioning dialysis access fistula in the left arm
26. In high risk patients for spinal cord ischemia:
– patients requiring extensive coverage of the
thoracic aorta where critical intercostal arteries
originate;
– patients who have undergone infrarenal aortic
surgery (ligation of lumbar and middle sacral
arteries);
– patients with compromised hypogastric blood
supply
27.
28. Use of chimney grafts in aortic arch pathologies involving the supra-aortic
branches.
Gehringhoff B; Torsello G; Pitoulias GA; Austermann M; Donas KP.
J Endovasc Ther; 18(5): 650-5, 2011 Oct
CONCLUSION: The use of chimney grafts in selected aortic arch pathologies with
involvement of supra-aortic branches is safe and feasible. Long-term results were
questionable due to most early occluded dspite of short term high success rate.
Eur J Vasc Endovasc Surg. 2013 Jun;45(6):633-8. doi: 10.1016/j.ejvs.2013.02.016. Epub
2013 Mar 27.
The single-centre experience of the supra-arch chimney technique in endovascular
repair of type B aortic dissections.
CONCLUSIONS:
In repairs for type B ADs, the chimney technique provides a minimally invasive way of
preserving flow to the arch branches combined with a favourable mid-term outcome.
The stents seemed to be related to a higher probability of the immediate type I
endoleaks.
29.
30. Conclusions
• TAR with 2nd
stage TEVAR for complex arch
pathology
• Debranching & proximal ligation
• Chimney = bailout
complications related to the densely adherent tissue surrounding the transverse aortic arch prosthesis and the vicinity of vital vascular and nervous anatomical structures, such as the pulmonary artery, the left recurrent laryngeal or vagus nerves, and the esophagus
the aortic arch was replaced first,
followed by the remaining affected aorta during a second operation some 4—12 weeks later
the one-stage operation due to the long duration of the procedure and hypothermic circulatory arrest,
two-stage operation due to the need for a second operation, which sometimes required another period of hypothermic circulatory arrest to perform the proximal anastomosis to the distal aortic arch. Furthermore, the approach to the distal aortic arch, usually via a left thoracotomy, was associated with surgical complication
Not require thoracotomy :
.Fewer systematic & cardiac complications .Less postoperative pain & blood loss.Fewer coagulation disorders.Reduced rate of spinal cord injury
.Reduced duration of mesenteric & visceral ischemia
.Reduced renal failure
Endovascular stent graft landing zones and hybrid arch repair classification scheme for arch aneurysms. The approach to hybrid arch repair is facilitated when the anatomy of the aortic arch aneurysm is analyzed with regard to 2 main concepts: (1) distal and proximal stent graft landing zone evaluation, and (2) optimization of circulatory management for great vessel revascularization scheme. Both these anatomical concepts are closely related and therefore must be approached in conjunction.
Proximal landing zone classification for TEVAR. Typically, thoracic endovascular stent grafts are proximally landed in zones (Z) 2 or 3. Z3 landing is distal to the left subclavian artery (LSCA), but in aneurysms approaching the LSCA, it can be difficult for stent graft landing to achieve a satisfactory seal with no evidence of endoleak. In these patients, Z2 landing zone is required and this occurs between the left common carotid artery (LCCA) and LSCA, thus obligating occlusion of the LSCA. Therefore, typically LCCA-to-LSCA bypass is performed at our institution a few days before the TEVAR procedure. Of note, abandoning the bypass carries a risk for postoperative left upper extremity ischemia and posterior circulatory stroke (ie, dominant vertebral artery). In patients with left internal mammary to coronary artery bypass graft, the LCCA-to-LSCA bypass is a requirement to preserve mammary artery flow. In TEVAR, Z0 and Z1 landing is prohibitive, as it would necessitate occlusion of the head vessels. The hybrid arch concept is an extension of the TEVAR proximal landing zone scheme. Hybrid arch procedures are typically performed with the proximal landing zone in Z0. Therefore, the arch hybrid concept necessitates a brachiocephalic revascularization procedure to preserve flow through the great vessels.
(B) The hybrid arch repair classification is based on aortic arch aneurysm anatomy and proximal and distal landing zone feasibility.
The scheme divides aortic arch aneurysms into 3 types.
Type I arch hybrid is performed typically with a classic arch aneurysm, where the ascending and descending thoracic aorta are not aneurysmal or dissected–isolated arch aneurysm. This anatomy has favorable proximal Z0 and distal Z3/Z4 landing zones, respectively. A type I arch hybrid repair only requires great vessel revascularization with either concomitant antegrade TEVAR stenting or delayed retrograde TEVAR from the iliofemoral vasculature.
A type II arch hybrid is an ideal approach in an arch aneurysm without a good Z0 proximal landing zone, but has a good distal landing zone in the descending thoracic aorta. Therefore, a type II repair necessitates an open surgical Z0 landing zone reconstruction for proper deployment and seal of the proximal stent graft.
Type III arch hybrid repair can be used for even more complex aortopathies, such as the mega-aorta syndrome. In this case, the native aorta does not have a good proximal or distal landing zone for stent graft deployment. Therefore, a type III repair necessitates an open surgical reconstruction of proximal aorta and arch as a total arch replacement with elephant trunk for stent graft landing in the descending thoracic aorta. It is important to note that in the progression from a type I to type III arch hybrid repair, the circulatory management options become increasingly complex, and therefore, must be tailored to patient status and anatomy.
Hybrid approaches are classified into three types
according to the extent of aortic arch lesion and the presence of the proximal and distal landing zone:
(I) Type I: the debranching procedure consists of brachiocephalic bypass and endovascular repair of the aortic arch. This approach is reserved for patients with isolated aortic arch aneurysms that exhibit an adequate proximal landing zone in the ascending aorta and a distal landing zone in the descending thoracic aorta.
(II) Type II: this hybrid approach is designed for patients with ascending aortic lesions with a limited extension into the distal arch. A type II repair entails an open ascending aorta reconstruction that “creates” an appropriate proximal landing zone, great vessel revascularization, and endoluminal aneurysm exclusion.
(III) Type III: an elephant trunk procedure with a complete endovascular repair of the thoracoabdominal aorta. This technique is reserved for patients with extensive aortic lesions that involve the ascending, transverse arch, and descending thoracic aorta, or the “mega-aorta syndrome”.
The majority of the patients (62.0%) underwent arch debranching attributable to degenerative aneurysms, with 28.6% attributable to aortic dissection, 2.2% attributable to a pseudoaneurysm or traumatic transection, and 7.2% attributable to other aortic pathologies such as penetrating ulcers, intramural hematomas, aortobronchial fistula, intracranial aneurysm, endoleak correction after thoracic aortic aneurysm, and floating thrombus in the aortic arch. Zone 0 was involved in 342/820 (41.7%) patients, Zone 1 in 237/820 (28.9%) patients, and Zone 2 in 241/820 (29.4%). Almost 74% of the patients were referred for elective treatment, with the remainder operated on in an emergent/ urgent setting. A single-stage approach was implemented in 52.9% of patients, while 47.1% underwent a staged procedure with a mean intra-procedural interval of 18.5 days (95% CI: 7.6-29.4 days). Cardiac arrest was utilized in 9.2% (67/731) of the patients. Mean ICU stay was 2 days (95% CI: 1.1- 3.0 days), and mean length of hospital stay was 12.1 days (95% CI: 8.2-15.9 days). Mean follow-up period was 22.1 months (95% CI: 18.2-26.1 months).
With respect to the primary technical success, which was defined as complete aortic arch debranching and successful stent-graft deployment, the pooled estimate was 92.8% (95% CI: 89.1-95.3%) (Figure 3). Of the 894 patients for whom both stages of the procedure were completed, 149 (16.6%) experienced an endoleak. In particular, 165 endoleaks were detected in follow-up CT scans: 106 type I, 51 type II, and 8 type III. Among 17 studies which provided relative data, retrograde type A dissection was observed with a pooled rate of 4.5% (95% CI: 2.9-6.8%) (Figure S1).