Aortic arch reoperation in a single centre: early and late results in 57 consecutive patients

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1 European Journal of Cardio-Thoracic Surgery Advance Access published April 21, 2013 European Journal of Cardio-Thoracic Surgery (2013) 1 5 doi: /ejcts/ezt205 ORIGINAL ARTICLE Aortic arch reoperation in a single centre: early and late results in 57 consecutive patients Monica Moz*, Martin Misfeld, Sergey Leontyev, Michael Andrew Borger, Piroze Davierwala and Friedrich-Wilhelm Mohr Department of Cardiac Surgery, Heart Center Leipzig, University of Leipzig, Leipzig, Germany * Corresponding author. Leipzig Heart Center, Struempellstrasse 39, Leipzig, Germany. Tel: ; fax: ; moz.monica1@googl .com (M. Moz). Received 15 September 2012; received in revised form 26 February 2013; accepted 5 March 2013 Abstract OBJECTIVES: Aortic arch surgery following previous replacement of the ascending aorta has become more frequent due to the improved long-term survival of patients after the primary procedure and advances in the management of complex repeat cardiac procedures. We retrospectively analysed our results of redo aortic arch surgery. METHODS: Between January 1995 and December 2011, a total of 1022 patients underwent surgery on the ascending aorta with or without involvement of the aortic arch. Of these, 57 patients (5%) underwent reoperations involving the aortic arch. Indications for repeat aortic arch surgery included arch aneurysm in 50%, residual aortic dissection with aneurysmal formation in 38%, and graft infection in 9% of patients. One patient (1%) underwent previous heart transplantation. Nine patients (16%) had Marfan syndrome. RESULTS: Mean age was 55 ± 15 years and 23 patients (40%) were female. Logistic EuroSCORE-predicted risk of mortality was 38 ± 19%. The mean time interval between primary and redo surgery was 7.6 ± 7 years for aortic aneurysm and 4.4 ± 4 years in aortic dissection patients (P = 0.09). Total and partial arch replacements were performed in 52 and 47% of patients, respectively. Mean circulatory arrest time was 28.3 ± 22.1 min, with selective antegrade cerebral perfusion (SACP) utilized in 68% of patients. Overall incidence of stroke or transient neurological deficit was 15%. The 30-day mortality was 9% (n = 5). Multivariable logistic regression analysis revealed that previous type A aortic dissection was the only independent risk factor (OR 3.7, 95% CI , P = 0.01) for 30-day mortality. Mean survival was 5.5 ± 0.5 years, and estimated 5-year survival was 74.9 ± 0.6%. Survival of patients undergoing reoperation for residual aortic dissection was significantly worse compared with patients with aortic arch aneurysm (log-rank P = 0.016). CONCLUSIONS: Aortic arch reoperation, although a technically complex operation, can be performed with acceptable mortality and morbidity. Patients with aortic dissection during their previous operation required repeat surgery significantly earlier when compared with patients with arch aneurysms, and had worse long-term survival. Keywords: Aortic arch reoperation Redo cardiac surgery Outcome INTRODUCTION Aortic arch reoperations in patients who have previously undergone surgery of the ascending aorta/aortic arch are technically complex procedures. Better long-term survival after the primary procedures, an ageing general population and improved knowledge and expertise in the preoperative management of patients undergoing aortic arch surgery are some factors that have contributed to a rise in the number of these procedures. In addition, regular follow-up of aortic surgery patients with advanced imaging techniques may result in the identification of a larger number of patients with indications for redo aortic arch surgery. Aneurysmal dilatation and/or dissection of the aortic arch following previous ascending aorta surgery, infection of prosthetic Presented at the 26th Annual Meeting of the European Association for Cardio-Thoracic Surgery, Barcelona, Spain, October aortic grafts, and degeneration of biological conduits or homografts are the most common indications for repeat aortic surgery. Redo aortic arch operations are thought to be associated with higher early mortality and significantly higher morbidity than primary procedures, but previous studies have been limited by their small sample sizes. In order to more accurately quantify the risk of these procedures, we reviewed our experience in patients who underwent aortic arch surgery following previous aortic operations. MATERIALS AND METHODS Patient population A total of 1022 patients underwent surgery of the ascending aorta and/or aortic arch between January 1995 and December The Author Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

2 2 M. Moz et al. / European Journal of Cardio-Thoracic Surgery 2011 at our institution. Of these, 57 patients (5%) underwent aortic arch surgery following previous surgery on the aorta, and form the focus of this study. Table 1 depicts the indications for, and the type of, primary operation performed in patients who underwent aortic arch reoperation. The mean time interval between the primary and redo operation for the entire group was 7.3 ± 5.2 years. Patients who were primarily operated upon for type A aortic dissection had a shorter time interval between aortic operations (4.4 ± 4.1 years) than those who underwent previous surgery for aneurysmal disease (7.6 ± 7.3 years, P = 0.09). Patient demographics are listed in Table 2. Twelve patients (21%) underwent a third and 5 patients (8%) a fourth cardiac operation. Indications for repeat aortic surgery included aortic arch aneurysm (50%), residual aortic dissection (38%), and prosthetic valve and graft endocarditis (9%). One patient (1%) with end-stage dilated cardiomyopathy had previously undergone aortic valve replacement and then a Bentall operation for a paravalvular leak. Perioperative management at reoperation Preoperative investigations included a computerized tomographic (CT) scan of the thorax and entire aorta with a specific focus on: (i) diameter of the entire aorta; (ii) anatomical characterization of the supra-aortic branches; (iii) assessment and localization of potential residual aortic dissection and/or atherosclerotic plaques; and (iv) distance between the sternum and vital intrathoracic structures. Intraoperative management included invasive monitoring with a pulmonary artery catheter, and a left radial and femoral arterial line to assess systemic perfusion pressures during cardiopulmonary bypass (CBP). A catheter with a temperature probe was inserted to measure bladder temperature and urine output. Table 1: Indications and type of primary operation in patients undergoing reoperative aortic arch surgery Transcutaneous cerebral oxymetry (INVOS 3100 SD; Troy, MI, USA) was used in all cases since The aorta was approached through a median re-sternotomy in 48 patients (84%), while the remaining 9 (6%) underwent a left thoracoabdominal incision for aortic arch and descending aortic aneurysm. Arterial cannulation was performed via the axillary artery (52%) or femoral artery (47%). After aortic cross-clamping, myocardial arrest was achieved with antegrade cardioplegia delivered into the aortic root or directly into the coronary ostia, if aortic regurgitation was present. After cooling to the target core body temperature, the patient was placed in the Trendelenburg position and the head was cooled topically. As previously described [1], unilateral or bilateral selective antegrade cerebral perfusion (SACP) with cold oxygenated blood (24 C) was maintained with a flow rate of 10 ml/ kg/min and a right radial pressure between 40 and 60 mmhg. The decision to perform unilateral or bilateral SACP was at the discretion of the operating surgeon. In general, bilateral SACP was used in elderly patients or in those with atherosclerotic disease because of a higher risk of incomplete Circle of Willis perfusion. In addition, some patients who originally underwent unilateral SACP perfusion were switched to bilateral SACP when the INVOS signal revealed evidence of ipsilateral cerebral ischaemia. Following initiation of the circulatory arrest period, resection of all pathological aortic arch tissue was performed. In cases of total arch replacement, the supra-aortic vessels were reimplanted either as an island (en-bloc technique) or individually using a modified arch Hemashield graft (Maquet; Rastatt, Germany). Proximal graft-to-graft anastomosis and concomitant cardiac procedures were performed during the rewarming period. Follow-up Patients were followed annually with a mailed questionnaire or, when required, by contacting the referring cardiologist or general practitioner. Follow-up information was available for all discharged patients (100%) with a mean follow-up period of 5.5 ± 0.5 years. n % Indication for first operation Acute type A aortic dissection Aortic aneurysm Endocarditis 1 1 Type of primary operation Replacement of the ascending aorta (RAA) 7 12 Aortic valve replacement (AVR) + RAA 9 15 RAA + hemi-arch replacement AVR + RAA + hemi-arch replacement RAA + total arch replacement 2 3 Bentall + RAA Valve sparing root replacement 3 5 Bentall + RAA + hemi-arch replacement 8 14 Valve sparing + RAA + hemi-arch replacement 2 3 Thoraco-abdominal aneurysm repair + reverse ET 1 1 Associated procedures: Stent implantation in descending aorta 2 3 Time between operation (years) 7.3 ± 5 Acute type A aortic dissection 4.4 ± 4 Aneurysm 7.6 ± 7 Table 2: Demographic characteristics of patients undergoing redo aortic arch surgery Variables n % Female Age (years) (mean ± SD) 55 ± 15 NHYA Class III IV Hypertension Chronic pulmonary disease 5 9 Serum creatinine >2.0 mg/dl 1 1 Peripheral vascular disease Diabetes mellitus 4 7 Neurological dysfunction 5 9 Marfan syndrome 9 16 Urgent surgery 5 9 Logistic EuroSCORE (%) 38 ± 19

3 M. Moz et al. / European Journal of Cardio-Thoracic Surgery 3 Statistical analysis All statistical analyses were performed with the SPSS version 17.0 (SPSS, Chicago, IL, USA). Categorical variables are expressed as percentages and continuous variables are expressed as mean ± standard deviation throughout the article. Multivariable logistic regression with backward elimination was used to analyse the independent risk factors for 30-day mortality. Long-term survival was analysed with the method of Kaplan Meier. Statistical significance was defined as P < RESULTS Operative details Operative details are listed in Table 3. SACP with hypothermic circulatory arrest (HCA) was used in 39 patients (68%). Of these, unilateral and bilateral SACP were used in 11 and 28 patients, respectively. The mean minimum core body temperature during circulatory arrest was 25.1 ± 2.0 C. In 18 patients (46%), deep HCA was used with a mean temperature of 21.8 ± 1.9 C. Partial arch replacement was performed in 27 patients (47%) and total arch replacement in 30 (52%) Of the latter, 16 patients underwent a conventional elephant trunk procedure and 6 a frozen elephant trunk procedure with a stent-graft prosthesis (E-vita Open Plus, Jotec GmbH; Hechingen, Germany). In patients undergoing total arch replacement, reimplantation of the supra-aortic vessels was performed with the island technique in 22 patients and as a separate graft technique in 8, depending on the quality of aortic arch tissue and the presence of a dissection flap or atheromatous plaque. Four patients (7%) with an infected vascular graft and aortic valve endocarditis underwent aortic root replacement with a homograft conduit and arch replacement using the distal segment of the aortic homograft. Other associated procedures included: coronary artery bypass in 9 patients (15%), mitral valve repair in 2 (3%), tricuspid valve repair in 2 (3%), replacement of the thoracoabdominal aorta in 9 (15%) and a maze procedure in 2 (3%). Early results Perioperative outcomes are detailed in Table 4. The 30-day mortality rate was 9% (n = 5). Three patients died in the Table 3: Variables Intraoperative data Cardiopulmonary bypass time (min) (mean ± SD) ± 84 Cross-clamp time (min) (mean ± SD) 99.4 ± 60.4 Circulatory arrest time (min) (mean ± SD) 28.3 ± 22.1 Arterial cannulation site, n (%) Femoral artery 27 (47%) Axillary artery 30 (52%) Bentall procedure, n (%) 20 (35%) Homograft 4 (7%) Hemi-arch replacement, n (%) 27 (47%) Total arch replacement, n (%) 30 (52%) Elephant trunk 16 (28%) Frozen elephant trunk 6 (10%) Thoraco-abdominal aortic replacement, n (%) 9 (16%) operating room (2 because of low cardiac output and 1 due to massive myocardial infarction), while 1 died due to massive cerebral edema on the seventh postoperative day and another died 23 days postoperatively due to sepsis and intestinal ischaemia. Prolonged length of stay in the intensive care unit (ICU) (defined as >10 days) was required in 5 patients (9%), predominantly for pulmonary problems. Eight patients (14%) needed readmission to the ICU (4 patients for respiratory failure, 2 for sepsis, 1 for acute pancreatitis and 1 for syncope due to ventricular fibrillation). Five patients (9%) required re-exploration for bleeding. Five patients (9%) required reintubation and 3 (5%) required a temporary tracheostomy due to prolonged ventilation. Four patients (7%) required a permanent pacemaker for complete heart block after surgery. Five patients (9%) required haemodialysis for acute renal failure. Stroke or transient ischaemic attack developed in 9 patients (15%), with 3 (5%) developing permanent neurological deficits. There was no difference in the development of cerebral complications among the different techniques of cerebral protection (see Table 4). No new injury of the recurrent laryngeal nerve occurred as a result of the arch surgery. One patient developed a deep sternal wound infection. The mean hospital length of stay was 30 ± 5 days. Univariate analyses revealed an association between the following factors and 30-day mortality: previous surgery for type A aortic dissection (OR 9.2, 95% CI , P < 0.01), emergency surgery (OR 8.2, 95% CI P = 0.02) and peripheral vascular disease (OR 5.5, 95% CI P = 0.02). Multivariable logistic regression analysis revealed that previous type A aortic dissection was the only independent risk factor (OR 3.7, 95% CI , P = 0.01) for 30-day mortality. Table 4: Postoperative outcomes Outcomes Frequency % 30-day mortality 5 9 Myocardial infarction 1 1 Cerebrovascular accident 9 16 Multiorgan failure 1 1 Renal failure with dialysis 9 16 Permanent pacemaker implantation 4 7 Reintubation 5 9 Re-exploration for bleeding 5 9 Intra-aortic balloon pump implantation 1 1 Postoperative LOS stay (days) (mean ± SD) 30 ± 5 Permanent neurological deficit 3 5 In relation to type of cerebral protection UACP 0 BACP 2 DHCA 1 Temporary neurological deficit 6 10 In relation to type of cerebral protection UACP 1 BACP 3 DHCA 2 LOS: postoperative hospital stay; UACP: Unilateral antegrade cerebral perfusion; BACP: Bilateral antegrade cerebral perfusion; DHCA: Deep hypotermic circulatory arrest.

4 4 M. Moz et al. / European Journal of Cardio-Thoracic Surgery Long-term results Overall survival rates were 77 ± 0.3, 76 ± 0.4 and 75 ± 0.6% at 1, 3 and 5 years, respectively. Survival for patients with residual aortic dissection was significantly worse when compared with those with aortic arch aneurysm (5-year postoperative survival 76 ± 1 vs 81 ± 1%, respectively, log-rank P = 0.016). (Fig. 1). Two patients required aortic valve replacement for endocarditis and 1, replacement of the thoraco-abdominal aorta. Two patients, who underwent hemi-arch replacement at their reoperation, required re-replacement of the complete arch due to residual dissection and aneurysmal dilatation. One- and 5-year freedom from reoperation rates were 98 ± 1 and 95 ± 2%, respectively. DISCUSSION Reoperation on the aortic arch following surgery of the ascending aorta and/or aortic arch is associated with increased risk due to the surgical complexity and variability in clinical and anatomical features. We reviewed our experience with reoperative arch surgery performed over a 16-year period. To the best of our knowledge, the current study is one of the largest single-centre experiences in the literature. Indications for redo procedures can be classified into three major categories: aortic arch aneurysm, progressive aortic arch dilatation in patients who underwent primary surgery for acute type A aortic dissection and infection of previously implanted vascular grafts. There are many different aspects that need to be addressed in order to perform a successful aortic arch reoperation. Preoperative evaluation with CT scan images, with 3D reconstruction if possible, helps to identify the extent of aneurysmal dilatation as well as the presence and extent of a residual dissection (i.e. involvement of supra-aortic vessels and extension into the descending aorta). This enables the surgeon to formulate a surgical strategy that may necessitate additional replacement of the supra-aortic vessels and/or the use of an elephant trunk technique. A CT scan also shows the anatomical relationships of old aortic grafts or aneurysms to the sternum and surrounding structures, which may affect the choice of cannulation and surgical approach. Identification of atherosclerotic disease in the ascending aorta and/ Figure 1: Overall survival. or arch by CT scanning should lead the surgeon to minimize handling of the diseased aorta before establishing circulatory arrest, thus preventing dislodgement of emboli from the aorta and development of postoperative stroke [2]. Our current cannulation technique of choice for aortic arch surgery is via the axillary artery. This vessel is rarely diseased or involved in the dissection process, and thus can be safely cannulated directly or via an anastomosed graft [3]. We performed femoral artery cannulation early in the experience of the current study, however, as well as in those patients in whom the axillary artery was previously cannulated. The main risk of aortic arch surgery is postoperative neurological events [4, 5]. Cerebral emboli due to dislodgement of atherosclerotic debris from the diseased aorta and cerebral ischaemia due to temporary intraoperative interruption of blood supply during circulatory arrest are two major causes of neurological dysfunction. The use of HCA reduces cerebral metabolic demand during mandatory periods of ischaemia. But HCA alone may not be safe for prolonged circulatory arrest times exceeding min. An alternative approach is to cannulate the cerebral vessels with or without an interval of circulatory arrest with subsequent ACP [6]. The incidence of neurological injury in patients operated upon with the use of unilateral and bilateral ACP is 5% [7]. Bilateral perfusion may permit longer times of circulatory arrest compared with unilateral perfusion without increasing the rate of permanent neurological deficit [1]. However, selective cerebral perfusion may also lead to cerebral embolism during arch-vessel cannulation. Continuous monitoring of cerebral oxygenation using nearinfrared spectroscopy has been developed for evaluation of the adequacy of blood supply to the brain during periods of circulatory arrest. We have routinely used cerebral oximetry in all cases of aortic surgery since The INVOS signal provides a continuous non-invasive real-time measurement of cerebral oxygen saturation, allowing the early detection of malperfusion before irreversible damage develops [8, 9]. These of cerebral oximetry, in combination with ACP, has led some surgeons to switch from deep (18 C) to moderate hypothermia (28 C), even for complex aortic arch surgery [9]. The en-bloc technique or separate graft technique, using a fourbranched aortic graft or a trifurcated graft [10], are the two principal methods used for supra-aortic vessels reimplantation during aortic arch reconstruction. We use separate implantation of supra-aortic vessels in patients with residual aortic dissection with extension into the arch vessels, or if the island containing the origins of the supra-aortic vessels is heavily calcified, making direct anastomosis impossible. We also use this technique in patients with Marfan syndrome in whom the dilatation of the aortic arch may involve the proximal segments of the supra-aortic vessels. Patients with Marfan syndrome may require a reoperation due to progression of disease after the first aortic operation. We have previously shown that distal aortic reoperations can be performed with good long-term results in patients with Marfan syndrome [11]. Such patients should undergo regular imaging after any aortic operation in order to follow the progression of aortic disease [12]. Our good perioperative and long-term results for redo aortic arch surgery may have implications for surgical strategy during the original arch operation. In particular, one may use our results to support the concept of performing only partial arch replacement in patients presenting with acute type A aortic

5 M. Moz et al. / European Journal of Cardio-Thoracic Surgery 5 dissection. Some investigators have suggested that a frozen elephant trunk procedure should be routinely performed in patients presenting with acute type A dissection [13, 14]. However, such operations can be technically challenging, particularly if the distal aortic arch is of small caliber or fragile in nature. Our institutional policy is to perform hemi-arch replacement in patients presenting with acute type A dissection, except in those presenting with an entry or re-entry tear in the arch, with a dilated (>4.0 cm) proximal descending aorta, or Marfan syndrome. LIMITATIONS In addition to its retrospective nature, our study has other limitations. The group of patients is rather heterogeneous, including differences in types of previous operation performed, indications for reoperation and concomitant procedures performed. However, these operation are uncommon (5% of all patients undergoing aortic surgery during the study period), limiting the analysis to a small subgroups of patients. CONCLUSION Despite the complexity of the procedure, redo aortic arch surgery can be performed with a relatively low perioperative mortality and morbidity, and with good long-term results. Careful preoperative assessment using CT scan imaging, along with preoperative development of an appropriate surgical strategy, is key to the successful performance of these challenging procedures. FUNDING Conflicts of interest: none declared. REFERENCES [1] Misfeld M, Leontyev S, Borger MA, Gindensperger O, Lehmann S, Legare JF et al. What is the best strategy for brain protection in patients undergoing aortic arch surgery? A single center experience of 636 patients. Ann Thorac Surg 2012;93: [2] Gulbins H, Pritisanac A, Ennker J. Axillary versus femoral cannulation for aortic surgery: enough evidence for general recommendation? Ann Thorac Surg 2007;83: [3] Budde JM, Serna DL, Osborne SC, Steele MA, Chen EP. Axillary cannulation for proximal aortic surgery is as safe in the emergent setting as in elective cases. Ann Thorac Surg 2006;82: [4] Okita Y, Ando M, Minatoya K, Kitamura S, Takamoto S, Nakajima N. Predictive factors for mortality and cerebral complications in atherosclerotic aneurysm of the aortic arch. Ann Thorac Surg 1999;67:72. [5] Griepp RB. Cerebral protection during aortic arch surgery. J Thorac Cardiovasc Surg 2001;121: [6] Kazui T, Kimura N, Yamada O, Komatsu S. Surgical outcome of aortic arch aneurysms using selective cerebral perfusion. Ann Thorac Surg 1994;57: [7] Malvini PG, Scroscia G, Vitale N. Is unilateral antegrade cerebral perfusion equivalent to bilateral cerebral perfusion for patients undergoing aortic arch surgery? Interact CardioVasc Thorac Surg 2008;7: [8] Hirofumi O, Otone E, Hiroshi I, Satosi I, Shigeo I, Yasuhiro N et al. The effectiveness of regional cerebral oxygen saturation monitoring using near-infrared spectroscopy in carotid endarterectomy. J Clin Neurosci 2003;10: [9] Harrer M, Waldenberger FR, Weiss G, Folkmann S, Gorlitzer M, Moidl R et al. Aortic arch surgery using bilateral antegrade cerebral perfusion in combination with near-infrared spectroscopy. Eur J Cardiothorac Surg 2010;38: [10] Bischoff MS, Brenner RM, Scheumann J, Bodian CA, Griepp RB, Lansman SL et al. Long-term outcome after aortic arch replacement with trifurcated graft. J Thorac Cardiovasc Surg 2010;140:S1 6. [11] Girdauskas E, Kuntze T, Borger MA, Falk V, Mohr FW. Distal aortic reinterventions after root surgery in Marfan patients. Ann Thorac Surg 2008; 86: [12] Gott VL, Cameron DE, Alejo DE, Greene PS, Shake JG, Caparrelli DJ et al. Aortic root replacement in 271 Marfan patients: a 24-year experience. Ann Thorac Surg 2002;73: [13] Uchida N, Katayama A, Tamura K, Sutoh M, Kuraoka M, Ishihara H. Frozen elephant trunk technique and partial remodeling for acute type A aortic dissection. Eur J Cardiothorac Surg 2011;40: [14] Gorlitzer M, Weiss G, Meinhart J, Waldenberger F, Thalmann M, Folkmann S et al. Fate of the false lumen after combined surgical and endovascular repair treating Stanford type A aortic dissections. Ann Thorac Surg 2010;89: APPENDIX. CONFERENCE DISCUSSION Dr B. Mochtar (Maastricht, Netherlands): You showed your medium and longterm results. But what strikes me is that a large proportion of patients, 30%, had primary type A dissection and then a redo operation. With your large experience, would you not now advocate doing the primary type A dissection operation more aggressively, so as to also repair the aortic arch and avoid the need for possible reoperation? Dr Moz: In type A aortic dissection without involvement of the aortic arch, we always undertake ascending aorta and eventually hemiarch replacement. These patients had a diagnosis of type A aortic dissection at the first operation that only later involved the aortic arch. Dr Mochtar: So you don t do it routinely, that s my question now, after seeing your results, not only repairing the ascending aorta but also the aortic arch at the primary operation? Dr Moz: If in the preoperative CT scan or MRI there is no flap in the aortic arch, there is no indication for total arch replacement. Dr Mochtar: But we all know that type A dissection is mostly also involved in the aortic arch, not only the ascending aorta. So most surgeons we know only do the ascending aorta and after 3 or 4 years have to do a redo operation, a difficult redo operation. Dr Moz: Well, I think that there is no indication for an aortic arch replacement in patients with type A aortic dissection without involvement of the aortic arch. Dr Mochtar: My second question is about the strategy. Your approach is always median sternotomy. When is your indication to do a posterolateral thoracotomy for complex aortic arch surgery? Is it only, for example, for Marfan patients, or is it also in patients where you re now doing, let s say, all kinds of elephant trunk techniques? Because in the posterolateral situation you can also remove the descending aorta, you don t need to put in a stent. It s a drawback, I know, posterolateral thoracotomy, and it s demanding, but don t you consider it now in your hospital? Dr Moz: All the patients in this series were subjected to resternotomy. Nine patients also had a thoraco-abdominal aneurysm and in these cases we have replaced the aortic arch and the thoraco-abdominal aneurysm via posterolateral thoracotomy. Dr C. Etz (Leipzig, Germany): I just wanted to comment on Dr. Mochtar s remarks, because we just analysed our data on the entire series of type A aortic dissections from Leipzig; it s an almost 500-patient experience at this point. And I was surprised, too, to actually see (and we will present that next week at the AHA in Los Angeles) that the arch involvement, at least from the CAT scan, is not that dramatic and, apparently (I just got out the data here because I saw the slides) it s about 31% of the tricuspid patients and only 6% of the bicuspid patients. Actually, it s 40% of patients that have arch involvement. Because there is always discussion about this, I just want to clarify that. Dr C. Mestres (Barcelona, Spain): In your presentation you were talking about 30-day mortality, but in the abstract it states hospital mortality. I think you should be a bit clearer. So 30-day was equal to hospital mortality? Dr Moz: Hospital mortality. Dr Mestres: So no patient died after 30 days in the hospital? Dr Moz: Yes. Dr Mestres: It should be made very clear for the audience.