| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Eur J Cardiothorac Surg 2002;21:276-281
© 2002 Elsevier Science NL
a Department of Cardiothoracic Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands
b Dutch Perfusion Service, St. Antonius Hospital, Nieuwegein, The Netherlands
Received 18 September 2001; accepted 30 October 2001.
* Corresponding author. Tel.: +31-30-609-20-47; fax: +31-30-609-21-20
e-mail: m.schepens{at}antonius.net
 |
Abstract |
|---|
 Top Abstract 1. Introduction2. Patients and methods3. Results4. DiscussionAppendix AAppendix B. DiscussionReferences |
|---|
Key Words: Elephant trunk • Aortic aneurysm • Mega aorta • Aortic arch surgery
|
1. Introduction |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix AAppendix B. DiscussionReferences |
|---|
|
2. Patients and methods |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix AAppendix B. DiscussionReferences |
|---|
|
|
|
2.2. Operative procedure
Initially, we used the modified technique of Borst as it was described by Crawford [4]. The diameter of the dacron prosthesis is chosen after appropriate sizing of the aorta at the level of the left subclavian artery. A long heavy stay suture marks the proximal end of the prosthesis (ascending and/or proximal aortic arch). This part is then invaginated into the trunk part. This suture, which hangs out of the lumen of the folded prosthesis, will facilitate the unfolding process. The extent of invagination will determine the length of the trunk as well as the subsequent proximal part of the prosthesis. The whole graft is then inserted into the descending aorta; the double fold is positioned at the level of the distal arch anastomosis. In case of chronic dissection, all clots must be carefully removed out of the false lumen and the intimal flap must be resected over a length substantially longer than the trunk length in order to avoid trunk entrapment. In case of acute dissection, the layers should be united using teflon felt or a synthetic glue. Then the distal anastomosis is performed just distally to the origin of the left subclavian artery. In the exceptional circumstance, in which the diameter of the native aorta at the level of the left subclavian artery considerably surpasses that of the desired vascular prosthesis, we suppose to plicate the aorta in order to reduce its diameter and obtain congruence between prosthesis and aorta. After having constructed the distal anastomosis and before tying down the suture, the downstream aorta can be de-aired by resuming temporarily the retrograde flow from the femoral artery cannula. Then the prosthesis should be unfolded by traction on the stay suture. This facilitates gentle retrieval of the proximal part of the prosthesis. Afterwards an oval opening is cut into the prosthesis and the cerebral vessels are reimplanted as one island.
Since 1996, we have been using more often prefabricated aortic arch prostheses (InterGard Aortic Arch from Intervascular, La Ciotat, France) with side branches for the head vessels (39% of the total group). This makes the invagination technique almost impossible and the predetermined length of the trunk must simply be inserted into the descending aorta. Thereafter a circular anastomosis is performed which is more cumbersome due to the presence of the prosthetic arch side branches, which might interfere with an optimal view.
By means of the prosthetic side-arms, all the cerebral vessels can be reimplanted using various lengths of these separate branches.
It is essential to switch perfusion from retrograde to antegrade using a Y-piece in the arterial line via a cannula inserted directly in the arch prosthesis or alternatively via a side prosthesis sewn onto or already present on the prefabricated arch prosthesis opposite to the most distal arch vessel side branch. In the island reimplantation technique, the antegrade flow is restarted after the arch vessel reimplantation prolonging the time of total body ischemia. In the prefabricated arch prosthesis technique, antegrade perfusion is resumed after the left subclavian anastomosis is performed. Afterwards, one can choose to return to the heart first or to continue with the separate arch vessel anastomoses. We did not use intraoperative transesophageal echocardiography to verify the placement of the ET.
Cerebral protection was achieved either using deep hypothermic circulatory arrest (iso-electric electroencephalogram and rectal or nasopharyngeal temperature of 18°C) (7%), antegrade selective perfusion (uni- or bilateral) (75%) or a combination of both (18%). These techniques have been described extensively [5,6]. We did not use retrograde cerebral perfusion.
Subsequent distal repair (descending thoracic or thoracoabdominal) is performed using left heart bypass. During this repair, the midportion of the descending aorta distal to the free-floating end of the trunk (depending on aneurysm contours) is clamped first and the proximal part of the descending aneurysm in which the elephant trunk is to be expected (a few centimeters below the anastomotic suture line of the trunk), is opened longitudinally at its lateral aspect over a very short distance (maximally 2 cm). Through this incision, the trunk can be felt or becomes immediately visible lying against the lateral wall of the aneurysm obliterating the incision made in the aneurysmal wall. The trunk is grasped and clamped. This causes hardly any blood loss at all. However, abrupt but short bleeding must be anticipated. If the trunk cannot be found in this way, it is due to the fact that the aneurysm has been opened too distally.
2.3. Statistical analysis
All data were analyzed using SPSS (Statistical Package for Social Sciences, SPSS Inc., Chicago, IL) for Windows 8.0. Continuous variables are expressed as the mean±one standard deviation and categorical variables as percentages. The relationship between independent pre-, intra- and postoperative variables and hospital mortality or postoperative neurologic outcome was investigated by univariate analysis (using 
2, Fisher's exact test or Mann–Whitney U test). A P value of 0.05 was chosen for retention in the multivariate model. Logistic regression analysis was used. Survival analysis was performed by the Kaplan–Meier product limit method and compared with the log-rank test. The independent pre-, intra- and postoperative variables analyzed are shown in the Appendix A.
|
3. Results |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix AAppendix B. DiscussionReferences |
|---|
|
Documented (by direct laryngoscopy) left recurrent nerve paralysis occurred in 17 patients. Other morbidity are listed in Table 5.
|
|
|
|
4. Discussion |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix AAppendix B. DiscussionReferences |
|---|
From a technical point of view, we think that there are several particular pitfalls which should be stressed. Avoidance of the entrance of an already dissected operative field, the area around the distal aortic arch, the origin of the left subclavian artery in which vicinity runs the left vagus and left recurrent nerves as well as the thoracic duct and therefore avoiding laceration of vital vascular, neural and lymfatic tissue, was the most important reason why the idea of the elephant trunk was introduced by Borst. Marking the distal end of the ET by one or two metal clips for identification on plain chest roentgenogram or computer tomography seems unnecessary to us. Determination of the exact level of the end of the ET is not necessary for the next operative stage. If on the other hand, endovascular repair is planned at the second stage [10], it certainly might be useful to put clips on the end of the trunk since this will determine the exact level of the trunk end and it will facilitate trunk entry by the guide wire. The exact place where to open the aneurysm at the subsequent repair depends on the aneurysm contours, the level of the distal anastomosis performed during the first stage, the take-off of the left subclavian artery and the length of the trunk. Simply opening the proximal aorta around the ET, grabbing it and placing a clamp on it under moderate hypotension is an easy and quick manoever that causes hardly any blood loss. The presence of clots in the blind pocket around the ET substantially prevents blood loss during this manever. The administration of anticoagulation agents (coumadine or acetyl salisylic acid), the length of the trunk (the longer the trunk, the more stasis in the top of the blind pocket) and the diameter of the aneurysm at this particular segment will determine the formation of clots between the trunk and the native aneurysmal wall. Crawford described a patient with paraplegia after the insertion of a very long ET extending up to the diaphragm [4], probably due to the thrombotic occlusion of some critical intercostal arteries. Clots entrapped in the blind pocket can be removed at the second operation and but in any way remain outside the prosthetic reconstruction; therefore, there is no risk of thrombo-embolic complication in contrast to the ‘bidirectional’ ET [11] in which peripheral embolisation during the second (arch) stage might be a serious problem.
Trunk entrapment was completely absent in our series; extensive longitudinal excision of the intimal flap in case of chronic dissection and keeping the end of the trunk well above the double-channeled (dissected) aorta will avoid this potential problem. It will further guarantee that both the false and true lumen are equally perfused. We think that the ideal length of the trunk should be between 5 and 10 cm (less than 5 cm can give problems during the retrieval and longer than 10 cm can become dangerous for paraplegia).
The exact incidence of left recurrent nerve palsy in relation with this operation has never been reported before. We think that it is important to try to avoid this complication since postoperative pulmonary complications might be worsened if the left vocal cord is paralyzed. Another important point is to check the function of both vocal cords before surgery since the aneurysm itself can cause left recurrent nerve dysfunction due to compression. Avoiding injury to this nerve is however difficult and unpredictable. Circumferentially stripping off 0.5 cm of peri-aortic tissue using a peanut when the anterior aspect of the vagus nerve has been identified and total circular transection of the aorta just distal to the left subclavian artery from inside the aorta, might overcome injury to the nerve. Very often, however, the quality of the aorta in the region of the left subclavian artery is bad since we are dealing with atherosclerotic aneurysms in most cases or postdissection aneurysms, which might be surrounded by dense adhesions. We suggest to inform the patient of this potential complication before surgery.
Our analysis has shown that none of the examined variables had a significant impact on hospital mortality. Probably postoperative central neurologic damage is a reflection of the intraoperative cerebral protection. With a 4% permanent neurologic dysfunction, we have reached a relative low incidence and we attribute this to a considerable extent to the antegrade cerebral perfusion, which allows us to perform these extensive repair in a safe manner [5]. Although the numbers are small, the results of the analysis show that the risk for postoperative neurologic problems is lower when the patient can be operated on electively. In this setting, optimal neurologic surveillance can be achieved using electro-encephalogram, transcranial doppler and transcranial oxymetry as we do it routinely.
The time interval between the insertion of the ET and the second stage is another interesting matter of discussion. Reasons for postponing the second stage might be an insufficient diameter of the descending or thoracoabdominal aneurysm, a suboptimal recovery from the first operation, the development of medical conditions that make the patient unfit for the completion operation such as serious chronic pulmonary disease or cancer. We believe the patient should be fit enough to undergo the second step since it might even be more demanding compared to the first. Of course, waiting too long increases the risk of rupture of a remote aneurysm especially if the aneurysm is very large or has expanded quickly and the blood pressure is not adequately regulated. This particular complication might have been avoided in 4–7 patients in our series.
One could argue that the indication to perform an ET was made quite liberally since about 48% of the patients did not receive their second stage. Since our mortality and morbidity rate does not differ between procedures on the aortic arch with or without the ET extension (except for left recurrent nerve paralysis), we indeed decide liberally to perform the ET procedure in view of the benefits at the subsequent repair as soon as an even limited distal dilatation or aneurysm is present.
We conclude that the ET procedure as a first step can be performed with a fairly low mortality rate. Maybe this can be attributed to the optimal cerebral protection using antegrade cerebral perfusion keeping the incidence of permanent neurologic sequelae low. In case of emergency surgery, it is probably unwise to perform this procedure. After the ET procedure, all patients need a close aortic surveillance with special emphasis on the risk factors for early rupture.
|
Footnotes |
|---|
|
Appendix A |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix AAppendix B. DiscussionReferences |
|---|
Gender
Age
Etiology of the aneurysm
Dissection or not
Aortic valve insufficiency
Coronary artery sclerosis
Marfan syndrome
Preoperative central neurologic status
Hoarseness before surgery
Date of intervention (before or after 1990)
Operative mode (elective versus emergent)
Primary versus redo surgery
ECC+DHCA versus ECC+DHCA+ASCP versus ECC+ASCP
Surgeon
Duration of ECC, myocardial ischemia, body arrest, DHCA and ASCP (minutes)
Performed procedure
Associated procedures
Technical problems necessitating repeated cardioplegic arrest
Postoperative dialysis
Tracheotomy
Rethoracotomy
Myocardial infarction
Central neurologic dysfunction
Mediastinitis
|
Appendix B. Discussion |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix AAppendix B. DiscussionReferences |
|---|
What are your guidelines for performing the second stage operation? The elephant trunk procedure is supposed to make the second stage easier if we do it rather early. But I remember a patient that I have reoperated on early this year: she refused for 3 years to have the second stage, and when I opened the chest, the elephant trunk was not very useful as it was stuck into the aneurysm because of the long time between the two procedures? Do you have a range of delays to solve this problem?
Dr Schepens: Regularly we use a protocol which commands that we evaluate the patient back after the first step after 3 months. Then he or she is seen at the outpatient clinic and a CT scan performed simultaneously. If the diameter of the descending or thoracoabdominal aneurysm comes in the neighborhood of 6 cm, which is our limit for degenerative or atherosclerotic aneurysms, then the second stage is planned. If it is a Marfan patient, the limit is 5 cm.
With regard to your specific problem that the elephant trunk was stuck into the descending aneurysm, we have never seen this. Normally, as you probably know, in the Netherlands, most people are continuously on warfarin, many times even if they have no mechanical heart valve; this means that the number of clots retaining into the pocket between the aneurysmal wall and the elephant trunk itself is mostly very limited. In our experience, we have never seen the elephant trunk stuck onto the wall of the descending aorta.
I hope I have answered your question sufficiently.
Dr A. Moritz (Frankfurt, Germany): I want to make a point for a one-stage approach. We did it through a transverse sternotomy, and as long as the aneurysm is confined to the chest, it gives you the opportunity to do it in one procedure and the only thing you change is that you have a slightly larger incision. The advantage of doing it is that probably your arrest times will be shorter because you only have to do one patch for the aortic arch and that's it. The other things are done in periods of normal perfusion, or at least upper body perfusion.
I have one technical question. If you have a real large aneurysm at the subclavian artery, how do you perform the anastomosis? Sometimes you have to shrink a 6 cm aneurysm to a prosthesis size of 4 cm. That is technically not always easy, and I think there are also some limits by doing this.
Dr Schepens: With regard to your first question, we have no experience, as I said, with the single-step repair of these mega aortas using a transverse sternotomy, so I cannot answer your question objectively, but I will try to give my own idea.
We don't do it because we think that the respiratory problems related to this approach are higher than if you do it in two steps, because we think, again, that median sternotomy is not so demanding for the respiratory system than doing a transverse incision, or a median sternotomy plus thoracotomy.
Above this, I think we have always tried to reimplant as much as possible intercostal arteries in descending or thoracoabdominal aortic aneurysm repair. I think, in my opinion, that it is very difficult to perform this from anteriorly. If you go through the lateral aspect of the thorax, this is much easier.
With regard to your second question about the discrepancy in diameter, we are lucky to say that in most of these patients, more specific in 99 of the 100 patients, the aortic diameter at the level of the left subclavian artery, or just beyond it, was quite narrow. I don't know the exact reason for this, but very often you see that in these mega aortas there is a narrow zone just at that particular place. And in the one patient in whom this was not the case, we had to plicate the aneurysm. You can do this by making a longitudinal incision in the descending aneurysm and then do a repair, which means perform just a continuous transmural closure of the aneurysm in order to reef it. I think it is safer to reinforce this anastomosis with Teflon strips, because if you don't do so and you have bleeding problems afterwards in this area, you will never be able to reach this region again and there might be a serious risk that the patient will bleed to death.
Dr S. La Francesca (Rome, Italy): I don't know if I understood correctly, but you didn't operate on 32 patients because you thought the diameter wasn't large enough to operate on these patients? So you actually don't do the elephant trunk procedure when you think you are going to do for sure the second stage pretty soon? You actually wait. You kind of foresee the enlargement of the aneurysm and then again you wait and give the patient warfarin?
Dr Schepens: If I may correct you, we have even not operated upon 48 patients up to now, and I will tell you why. The basis of your question is, are we too liberal in implanting elephant trunks since in 50% of the cases, we didn't perform the second step yet? The major advantage of the elephant trunk is that at the second procedure, you don't have to dissect the hostile region of the left subclavian artery in which the left recurrent nerve is there, the vagus nerve is there, the anastomosis is there. So if you want to get into trouble, you should try to clamp the aortic arch. Because the morbidity and the mortality of isolated arch replacement compared to arch replacement plus elephant trunk is exactly the same in our hands, we are quite liberal in inserting an elephant trunk, because we think in advance that we will profit from it at the second stage. And that is the reason why we have done quite a number of elephant trunks and waited until the descending part of the aneurysm reaches a suitable diameter.
Dr La Francesca: Then I agree a hundred percent with that, but you do keep all patients on warfarin afterwards?
Dr Schepens: It is not my fault, but in the Netherlands there is an extensive use of warfarin; even if you have an appendicitis and you are 20, you risk to be put on a kind of anti-coagulation therapy when you are in the hospital.
Dr A. Haverich (Hannover, Germany): You said that you would absolutely discourage the audience in performing this operation in emergency and acute situations. There will be a poster presented this afternoon from our group where we did the David reconstruction combined with the total arch in 18 patients, and a number of them had also got elephant trunks. Once you are there with a total arch repair in acute aortic dissection, why not put in the elephant trunk to also facilitate late reoperation in, for instance, Marfan syndrome?
Dr Schepens: I think this is a very good question. In case of acute Type A aortic dissection, as you know, the friability of the tissues might cause serious problems. The primary goal of the repair is to save the life of the patient, and all kinds of variants of the operative technique, extensive or limited, have not shown much difference in outcome. I was the fool who performed the one elephant trunk in the acute Type A dissection, but I can assure you that I have been rather nervous during the intervention because the diameter was small and the tissues were very fragile. Introducing an elephant trunk into an acutely dissected aorta is therefore in my opinion asking for trouble. If it is a chronic dissection, this is totally different. But I agree, if you have a rupture of a degenerative aneurysm, probably it could be wise if you know in advance that the dilatation extends far into the descending part to implant an elephant trunk. That's correct.
|
References |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix AAppendix B. DiscussionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  M. Karck and H. Kamiya Progress of the treatment for extended aortic aneurysms; is the frozen elephant trunk technique the next standard in the treatment of complex aortic disease including the arch? Eur. J. Cardiothorac. Surg., June 1, 2008; 33(6): 1007 - 1013. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. Schwartz, M. Bakhos, A. Patel, S. Botkin, and S. Neragi-Miandoab Repair of aortic arch and the impact of cross-clamping time, New York Heart Association stage, circulatory arrest time, and age on operative outcome Interactive CardioVascular and Thoracic Surgery, June 1, 2008; 7(3): 425 - 429. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. T. Kouchoukos Complications and Limitations of the Elephant Trunk Procedure Ann. Thorac. Surg., February 1, 2008; 85(2): 690 - 691. [Full Text] [PDF]
|
|
|
|
|
|
L. G. Svensson, N. T. Kouchoukos, D. C. Miller, J. E. Bavaria, J. S. Coselli, M. A. Curi, H. Eggebrecht, J. A. Elefteriades, R. Erbel, T. G. Gleason, et al. Expert Consensus Document on the Treatment of Descending Thoracic Aortic Disease Using Endovascular Stent-Grafts Ann. Thorac. Surg., January 1, 2008; 85(1_Supplement): S1 - S41. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Pichlmaier, O. E. Teebken, H. Baraki, and A. Haverich The frozen elephant trunk technique MMCTS, March 29, 2007; 2007(0329): 1990. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. T. Kouchoukos, M. C. Mauney, P. Masetti, and C. F. Castner Optimization of Aortic Arch Replacement With a One-Stage Approach Ann. Thorac. Surg., February 1, 2007; 83(2): S811 - S814. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Baraki, C. Hagl, N. Khaladj, K. Kallenbach, J. Weidemann, A. Haverich, and M. Karck The Frozen Elephant Trunk Technique for Treatment of Thoracic Aortic Aneurysms Ann. Thorac. Surg., February 1, 2007; 83(2): S819 - S823. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A.A.M. Schepens Aortic arch replacement: the conventional 'elephant trunk' technique MMCTS, January 2, 2007; 2007(0102): 2006. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Svensson Invited commentary Ann. Thorac. Surg., August 1, 2006; 82(2): 546 - 547. [Full Text] [PDF]
|
|
|
|
|
|
F. Jault, A. Rama, L. Lievre, N. Bonnet, P. Leprince, A. Pavie, and I. Gandjbakhch Chronic dissection of the ascending aorta: surgical results during a 20-year period (previous surgery excluded). Eur. J. Cardiothorac. Surg., June 1, 2006; 29(6): 1041 - 1045. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. A. LeMaire, S. A. Carter, and J. S. Coselli The Elephant Trunk Technique for Staged Repair of Complex Aneurysms of the Entire Thoracic Aorta. Ann. Thorac. Surg., May 1, 2006; 81(5): 1561 - 1569. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Okada, T. Sueda, K. Orihashi, K. Imai, and K. Sato A modified elephant trunk technique: The 3-fold elephant trunk technique J. Thorac. Cardiovasc. Surg., December 1, 2005; 130(6): 1720 - 1722. [Full Text] [PDF]
|
|
|
|
 |
|
 R. K. Greenberg, F. Haddad, L. Svensson, S. O'Neill, E. Walker, S. P. Lyden, D. Clair, and B. Lytle Hybrid Approaches to Thoracic Aortic Aneurysms: The Role of Endovascular Elephant Trunk Completion Circulation, October 25, 2005; 112(17): 2619 - 2626. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Kirali, H. Ardal, V. Erentug, D. Mansuroglu, N. U Bozbuga, and C. Yakut Surgical Outcome of Subtypes of Aortic Arch Dissection Asian Cardiovasc Thorac Ann, December 1, 2004; 12(4): 300 - 305. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. J. Meijboom, B. E. Westerhof, G. J. Nollen, J. A.E. Spaan, B. A.J.M. de Mol, M. J.H.M. Jacobs, and B. J.M. Mulder Beta-blocking therapy in patients with the Marfan syndrome and entire aortic replacement Eur. J. Cardiothorac. Surg., November 1, 2004; 26(5): 901 - 906. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. T. Kouchoukos, M. C. Mauney, P. Masetti, and C. F. Castner Single-stage repair of extensive thoracic aortic aneurysms: Experience with the arch-first technique and bilateral anterior thoracotomy J. Thorac. Cardiovasc. Surg., November 1, 2004; 128(5): 669 - 676. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. G. Svensson, K.-H. Kim, E. H. Blackstone, J. M. Alster, P. M. McCarthy, R. K. Greenberg, J. F. Sabik, R. S. D'Agostino, B. W. Lytle, and D. M. Cosgrove Elephant trunk procedure: newer indications and uses Ann. Thorac. Surg., July 1, 2004; 78(1): 109 - 116. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. T. Strauch, D. Spielvogel, A. Lauten, J. D. Galla, S. L. Lansman, K. McMurtry, and R. B. Griepp Technical advances in total aortic arch replacement Ann. Thorac. Surg., February 1, 2004; 77(2): 581 - 590. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Spielvogel, M. N. Mathur, and R. B. Griepp Aneurysms of the Aortic Arch Card. Surg. Adult, January 1, 2003; 2(2003): 1149 - 1168. [Full Text]
|
|
|
|
|
|
D. Spielvogel, J. T. Strauch, O. P. Minanov, S. L. Lansman, and R. B. Griepp Aortic arch replacement using a trifurcated graft and selective cerebral antegrade perfusion Ann. Thorac. Surg., November 1, 2002; 74(5): S1810 - 1814. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Fleck, D. Hutschala, M. Czerny, M. P. Ehrlich, M.-T. Kasimir, M. Cejna, E. Wolner, and M. Grabenwoger Combined Surgical and Endovascular Treatment of Acute Aortic Dissection Type A: Preliminary Results Ann. Thorac. Surg., September 1, 2002; 74(3): 761 - 765. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
