Surgical outcomes for acute type A aortic dissection with aggressive primary entry resection

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1 European Journal of Cardio-Thoracic Surgery 50 (2016) doi: /ejcts/ezw111 Advance Access publication 3 April 2016 ORIGINAL ARTICLE Cite this article as: Inoue Y, Minatoya K, Oda T, Itonaga T, Seike Y, Tanaka H et al. Surgical outcomes for acute type A aortic dissection with aggressive primary entry resection. Eur J Cardiothorac Surg 2016;50: Surgical outcomes for acute type A aortic dissection with aggressive primary entry resection Yosuke Inoue, Kenji Minatoya*, Tatsuya Oda, Tatsuya Itonaga, Yoshimasa Seike, Hiroshi Tanaka, Hiroaki Sasaki and Junjiro Kobayashi Department of Cardiovascular surgery, National Cerebral and Cardiovascular Center, Osaka, Japan * Corresponding author. Department of Cardiovascular surgery, National Cerebral and Cardiovascular Center, Fujishiro-dai, Suita, Osaka, Japan. Tel: ; fax: ; minatoya@ncvc.go.jp (K. Minatoya). Received 7 September 2015; received in revised form 21 January 2016; accepted 1 February 2016 Abstract OBJECTIVES: An entry located at aortic arch in acute type A aortic dissection (AAAD) is uncommon. It remains controversial whether or not aggressive primary entry resection should be routinely performed in such patients. We have adopted an aggressive strategy of entry site resection, including total arch replacement (TAR) in patients with arch tears. The purpose of this study was to investigate the efficacy of our surgical management approach, using aggressive primary entry resection. METHODS: Between January 2000 and December 2014, we retrospectively reviewed the records of 334 patients with AAAD who underwent emergent surgery. The mean age was 67 ± 13 years (range, years). Ninety-five patients (28%) presented with shock vital status, and 84 patients (25%) manifested malperfusion of branched arteries. Primary entry resection was achieved in 95% of patients under an aggressive surgical strategy [hemiarch replacement for 173 (52%) patients and TAR for 161 (48%) patients] concomitant with 22 coronary artery bypass grafts and 38 root replacements. Ninety-six percent of hospital survivors (298/311) were followed for a median of 39 months (range, months). RESULTS: Operation, cardiopulmonary bypass, cardiac arrest, antegrade cerebral perfusion and lower body circulatory arrest times were 447 ± 170, 236 ± 93, 112 ± 74, 115 ± 81 and 54 ± 18 min, respectively. The 30-day mortality rate was 5.4%. The in-hospital mortality rate was 8.4% (6.9% at our hospital). Incidences of postoperative permanent neurological dysfunction, tracheotomy and newly permanent haemodialysis were 6.9, 8 and 2%, respectively, with no spinal cord injuries observed. Complete false lumen thrombosis was achieved in 57% of patients as visualized by postoperative computed tomography angiography. After 3, 5 and 10 years, overall survival rates were 81, 74 and 65%, respectively, and the percentages of patients free from downstream dissection-related reoperation were 89, 86 and 80%, respectively. Multivariable analysis demonstrated that the risk factors for downstream aortic reoperation were patent false lumen, residual primary entry tear and connective tissue disorder. CONCLUSIONS: The surgical outcomes following aggressive treatment of AAAD are satisfactory. False lumen thrombosis can be achieved in a relatively high proportion of patients using this technique, resulting in a low rate of subsequent downstream aortic reoperations. Keywords: Aortic dissection Frozen elephant trunk Primary entry resection Outcome INTRODUCTION Acute type A aortic dissection (AAAD) is still a challenging and fatal emergent disease with extremely dismal outcomes without surgical therapy. There is currently no consensus about the ideal surgical therapy for AAAD. Several reports have referred to entry-oriented surgery as the mainstream strategy for treating AAAD, and we have routinely performed this aggressive strategy Presented at the 29th Annual Meeting of the European Association for Cardio- Thoracic Surgery, Amsterdam, Netherlands, 3 7 October for primary entry resection. To achieve primary entry closure, we did not hesitate to perform total arch replacement (TAR), using concomitant conventional elephant trunk (ET) or root replacement. However, for critical patients, the need for extended aortic surgery may exceed life-saving surgery. In recent years, several reports have mentioned the utility of the frozen elephant trunk (FET) technique for patients with AAAD [1 3]. FET may provide a solution for improving AAAD surgical outcomes in the future. The purpose of this study was to evaluate the long-term results of our aggressive strategy for treating acute aortic dissection as one of the benchmark reports without FET. The Author Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

2 568 MATERIALS AND METHODS Y. Inoue et al. / European Journal of Cardio-Thoracic Surgery Surgical technique Patients From January 2001 to December 2014, 334 patients underwent emergent surgery for AAAD (mean age, 67 ± 13 years; range, years; 159 males). Figure 1A shows the patient distribution by age. Preoperative comorbidities included coma, 17%; coronary ischaemia, 6.6%; visceral ischaemia, 6.3%; leg ischaemia, 6.3%; pericardial effusion, 25% and connective tissue disease, 7.5% (Table 1). Figure 1: (A) Patient age distribution. (B) Patient primary entry tear location. Table 1: Patients characteristics n = 334 ( January 2001 December 2014) Male 48% (159/334) Mean age ± 2SD (range) 67 ± 13 (20 95) Preoperative comorbidity Coma 17% (57/334) Coronary ischaemia 6.6% (22/334) Visceral ischaemia 6.3% (21/334) Limb ischaemia 6.3% (21/334) Pericardial effusion 25% (83/334) Shock status 28% (95/334) Cardiopulmonary arrest before OR 7.5% (25/334) Connective tissue disorder 7.5% (25/334) Marfan syndrome 6.8% (23/334) Loeys Dietz syndrome 0.6% (2/334) Dissection type DeBakey Type I 69% (230/334) DeBakey Type II 21% (70/334) Retrograde dissection 8.7% (29/334) Unknown 1.3% (5/334) OR: operation room; SD: standard deviation. All operative manoeuvres were performed through a median sternotomy. Arterial cannulation was achieved primarily through right axillary and left common femoral cannulations (Fig. 2A) [4, 5]. In cases where the dissection extended up to the right axillary artery or required cardiopulmonary resuscitation, single femoral artery cannulation was selected to immediately establish cardiopulmonary bypass. We routinely performed primary entry resection by all means. If we found primary entry tear located at reachable distal aorta through median approach, we performed TAR without hesitation. In cases with primary entry located at descending aorta or unknown (6%), the need for additional total arch reconstruction depended on patient age, presence of background connective tissue disease, preoperative condition and diameter of the aortic arch. In our series, primary entry located at aortic arch accounted for 25% (83/334) of cases (Table 2). In addition, the incidence of patients with a primary entry tear located at the aortic arch decreased with increasing patient age (Fig. 1B). Figure 2: (A) Establishment of cardiopulmonary bypass. (B) Intraoperative surgical view after the establishment of selective cerebral perfusion. AXA: axillary artery; FA: femoral artery; SCP: selective cerebral perfusion.

3 Y. Inoue et al. / European Journal of Cardio-Thoracic Surgery 569 Table 2: findings Surgical procedures, intraoperative variables and n = 334 Main surgical procedures Hemiarch replacement 52% (173/334) Adventitial inversion technique for distal 30% (52/173) anastomosis Felt sandwich technique for distal anastomosis 70% (121/173) Total arch replacement 48% (161/334) Concomitant procedure CABG 6.6% (22/334) AVR 2.1% (7/334) Aortic root procedure 11% (38/334) Modified Bentall procedure 7.5% (25/334) David-type valve sparing root replacement 2.9% (10/334) Partial remodelling procedure 0.8% (3/334) Limb bypass 3.3% (11/334) Location of primary entry Ascending aorta 69% (231/334) Aortic arch 25% (83/334) Descending aorta or unknown 6% (20/334) Operation time (mean ± SD) (min) 447 ± 170 Cardiopulmonary bypass time (mean ± SD) (min) 236 ± 93 Selective cerebral perfusion time (mean ± SD) (min) 115 ± 81 Lower body circulatory arrest time (mean ± SD) (min) 54 ± 18 Heart ischaemic time (mean ± SD) (min) 112 ± 74 Arterial perfusion site Rt axillary artery and unifemoral artery 84% (280/334) Ascending aorta (central cannulation) 4% (13/334) Unifemoral artery only 12% (41/334) Lowest nasopharyngeal temperature (mean ± SD) ( C) 23 ± 2.8 SD: standard deviation; AVR: aortic valve replacement; CABG: coronary artery bypass grafting. Open distal anastomosis was performed regularly under moderate hypothermic circulatory arrest (20 28 C) and antegrade selective cerebral perfusion (Fig. 2B). We avoided clamping the ascending aorta because of the risk of an embolic event, malperfusion syndrome or a new intimal tear. In patients undergoing TAR (48%, 161/334), all distal anastomosis was performed, using a conventional ET rather than an FET. When hemiarch replacement (HAR) was performed (52%, 173/334), we routinely replaced the ascending aorta just below the innominate artery and beyond the top of the pericardium. Reinforcement of the distal anastomosis was made, using the felt sandwich technique (70%) or adventitial inversion technique (30%). Since 2013, we have routinely utilized the adventitial inversion technique. For a proximal anastomosis occurring after 2013, we routinely performed a stepwise proximal anastomosis technique, using a separate short piece of graft because of some merit such as secure and easy anastomosis. Prior to 2013, we directly anastomosed a distal graft with a felt strip applied to the proximal site after fixation of the dissected wall. Dacron graft was used for both graft replacement and conventional ET in all cases. Either fibrin sealant or BioGlue was typically applied to obliterate the false lumen and to reinforce the stump of the proximal aorta. No glues were applied for distal anastomosis. Concomitant procedures included coronary bypass grafting (22 patients); aortic valve replacement (AVR) (7 patients); aortic root surgery, such as modified Bentall- or David-type aortic valve sparing root replacement (38 patients) and limb bypass surgery (11 patients) (Table 2). Patient follow-up The median duration of follow-up was 39 months (range, months), with a follow-up rate of 96% (298/311). Follow-up computed tomography (CT) examinations were performed 1 week after (304/334) and 6 months after the operation and yearly thereafter. A follow-up CT image was available for 91% (285/311) of our hospital survivors. Definitions A thrombosed false lumen located as far as the diaphragm level that was detected by postoperative contrast CT angiography at the delayed phase was defined as a complete false lumen thrombosis. Hospital mortality was defined as a death occurring in our hospital and at hospital discharge. Permanent neurological dysfunction was defined as a newly developed neurological deficit that had been confirmed by postoperative CT. Dissection-related reoperation contained descending and thoracoabdominal aortic surgery except for isolated infra-renal abdominal aortic surgery. Statistical analysis All statistical analyses were performed using EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan), which is a graphical user interface for R (The R Foundation for Statistical Computing, Vienna, Austria) [6]. Specifically, EZR is a modified version of R commander designed to add statistical functions frequently used in biostatistics. Nominal variables were evaluated using χ 2 analysis, whereas continuous variables were analysed using the Mann Whitney U-test. Long-term survival and freedom from reoperation were estimated by the Kaplan Meier method and the log-rank test. A Cox proportional hazard regression model was applied for the multivariate analysis of the freedom from reoperation. Statistical significance was accepted when P < RESULTS The mean operation time was 447 ± 170 min, the mean cardiopulmonary bypass time was 236 ± 93 min, the mean ischaemic heart time was 112 ± 74 min and the mean lower body circulatory time was 54 ± 18 min. The mean lowest nasopharyngeal temperature was 23 ± 2.8 C (Table 2). The 30-day mortality was 5.4% (18/334). In-hospital mortality was 8.4% (28/334) in all cases. There were 5.2% (16/309) of patients without a recorded preoperative cardiopulmonary arrest (CPA) status, and the preoperative CPA status was available for 44% (12/25) of cases (Table 3). Postoperative complications included permanent neurological dysfunction in 23 patients (6.8%), prolonged ventilation time of >72 h in 106 patients (32%), tracheostomy in 28 patients (8%) and newly permanent haemodialysis in 7 patients (2%). There were no incidences of paraplegia developing secondary to a spinal cord injury (Table 3). Postoperative contrast CT angiography was performed in 91% of patients and revealed that 57% (173/304) of patients had false lumen thrombosis. Between the patients that had undergone HAR and TAR, patients in the TAR group were significantly younger than those in the HAR group. From a viewpoint of mortality and survival rates,

4 570 Y. Inoue et al. / European Journal of Cardio-Thoracic Surgery Table 3: TAR was not a risk factor for operative death (HAR, 9.3% vs TAR, 7.4%, P = 0.56) and patient life expectancy (P = 0.35) (Table 4). The median follow-up time was 39 months, with a follow-up rate of 96% (298/311). In all patients, the survival rates at 3, 5 and 10 years after surgery were 81, 74 and 65%, respectively. There was no significant difference in patient long-term survival between HAR and TAR. The percentages of patients free from dissection-related downstream aortic reoperation at 3, 5 and 10 years were 89, 86 and 80%, respectively (Fig. 3A and B). The frequency of downstream aortic reoperation in patients with a patent false lumen was significantly higher than in those with a thrombosed false lumen (Fig. 3C). Table 5 shows the results of a Cox proportional hazard analysis of putative predictors of the need for late downstream aortic reoperation. The Cox proportional hazard regression model revealed that false lumen status, residual primary entry and existence of connective tissue disease were all significant risk factors that were predictive of the need for late downstream aortic reoperation. DISCUSSION Postoperative variables n = 334 Early mortality Operative death within 30 days 18 (5.4%) In-hospital death after 30 days 10 (3%) In-hospital death in our hospital 6.9% (23/334) In-hospital death in all cases 8.4% (28/334) In-hospital death in cases without CPA 5.2% (16/309) In-hospital death in cases with CPA 44% (12/25) Early complication Prolonged ventilation (>72 h) 32% (106/334) Tracheostomy 8% (28/334) Permanent neurological dysfunction 6.9% (23/334) Spinal cord injury 0% Newly permanent haemodialysis 2% (7/334) Transient haemodialysis 9.9% (33/334) Thrombosed false lumen rate (CT angiography) 52% (173/304) Late mortality n = 311 Aorta-related death 9 Cerebrovascular accident 7 Malignancy 4 Infection 10 Late morbidities Additional aortic root or cardiac operation 6.1% (19/311) Additional dissection-related downstream operation 8% (25/311) Open repair of descending or 6.1% (19/311) thoracoabdominal aorta Thoracic endovascular aortic repair 1.9% (6/311) CPA: cardiopulmonary arrest; CT: computed tomography. AAAD is a serious and fatal cardiovascular emergency that can result in sudden death. Although there are reports showing improved surgical outcomes, the latest report from the International Registry of Acute Aortic Dissection stated that the in-hospital mortality rate was still high at 23.9% [7]. We have reported good surgical outcomes and the importance of aggressive primary entry resection to prolong patient survival [5]. Table 4: Sub-group outcomes compared between hemiarch replacement and total arch replacement Variables Hemiarch (173) Total arch (161) Background Mean age ± 2SD (range) 71 ± ± 12 <0.001 Male 62 (35%) 97 (60%) <0.001 Connective tissue disease 6 (3.4%) 19 (12%) Dissection classification DeBakey classification Type I 105 (61%) 125 (78%) Type II 52 (30%) 18 (11%) <0.001 Type III (retrograde dissection) 5 (3%) 18 (11%) Location of primary entry tear Ascending 152 (88%) 79 (49%) <0.001 Aortic arch 10 (6%) 73 (45%) <0.001 Descending aorta or unknown 11 (6%) 9 (6%) NS Concomitant procedure Aortic root surgery 22 (13%) 16 (10%) NS CABG 12 (7%) 10 (6.2%) NS Operative variables Operation time (mean ± SD) (min) 425 ± ± 221 <0.001 CPB time (mean ± SD) (min) 210 ± ± 136 <0.001 SCP time (mean ± SD) (min) 58 ± ± 64 <0.001 In-hospital mortality 16 (9.3%) 12 (7.4%) 0.35 CPB: cardiopulmonary bypass; SCP: selective cerebral perfusion; SD: standard deviation. The primary goal of emergent surgery for AAAD is to save the patient s life. Surgical correction included relief from cardiac tamponade, resection of a tear and correction of malperfusion. In majority of the patients, these goals could be achieved by replacing the ascending aorta and resecting the entry tear. This is because the AAAD primary entry tear is usually located at the ascending aorta and is less likely to be found at the aortic or distal arch. Because additional arch replacement or root replacement results in a high-risk operation, the strategy of performing aggressive primary entry resection remains controversial. There are anecdotal reports of the routine ascending aortic replacements regardless of whether or not the entry resection is complete [8]. Miller et al.[9] reported that the primary tear in AAAD was located at the aortic arch in 10% of patients; however, in our series, a primary entry at the aortic arch was evident in 25% of cases, in which the proportion of the primary entries located at the aortic arch should not be ignored. In addition to our previous study [5], several other reports have concluded that performing extended aortic surgery to achieve primary entry resection is justified from the viewpoint of potential mortality and the ability to prevent a dissection-related reoperation [10, 11]. According to the subgroup analysis of operative mortality and long-term results, our surgical outcomes were satisfactory despite our aggressive strategy. Reasonable surgical outcomes were most likely obtained because we have standardized the surgical strategy of TAR using a four-branched graft. All surgeons are used to the strategy of TAR and will not hesitate to perform TAR even in an emergent setting [12]. Figure 3 shows that octogenarians and non-agenarians rarely had a primary entry tear located at the aortic arch (11%, 7/60 patients) compared with those <80 years of age (29%, 76/254 patients). We achieved entry-oriented surgery for elderly patients with attention to their comorbidities. However, as a result, we did

5 Y. Inoue et al. / European Journal of Cardio-Thoracic Surgery 571 Table 5: Results of Cox proportional hazard analysis for predictors of downstream dissection-related reoperation Variable P-value Hazard ratio 95% CI Residual primary entry tear Connective tissue disorder Thrombosed false lumen CI: confidence interval. Figure 3: (A) Postoperative survival curve for all patients. (B) Freedom from dissection-related downstream aortic reoperation. (C) Freedom from dissection-related downstream aortic reoperation for patients with a thrombosed versus a patent false lumen. not have to perform TAR in this higher risk group. El-sayed et al. [13] reported that 82% of octogenarian patients underwent HAR, which was similar to the rate in our cohort. In recent years, the effectiveness of the FET technique for AAAD has been reported to improve surgical outcomes. When FET could close the primary entry located beyond the distal anastomosis, the anastomosis site could be translocated to the proximal arch. Thus, FET has been implanted as it is expected to aid primary entry closure without the use of a traditional entry resection. However, FET itself could make a new entry along FET with its radial force. Moreover, long-term outcomes following the use of FET for primary entry closure remain unknown. FET was originally used with TAR; however, it has also been utilized with the hemiarch replacement. A hemiarch and stent-graft technique was reported by the Roselli s research group in Cleveland. Patient mortality was 0%, and the false lumen thrombosis rate was 88%. This simple procedure could be considered as an option that minimizes surgical invasiveness, especially for highrisk patients. However, this report provided short-term results, and long-term results were still unknown [14]. In our study, residual primary entry was a significant risk factor for downstream reoperation. More specifically, among patients without primary entry resection, 5 patients underwent the downstream reoperation, 1 patient died from aortic rupture and 1 patient manifested redissection. Because several reports noted the efficacy of primary entry resection for patients with AAAD, tear-oriented surgery has been widely recommended [15, 16]. We believe that traditional primary entry tear resection should remain a mainstream surgical strategy. In the future, the use of FET for primary entry closure may be a better surgical strategy for AAAD, resulting in improved surgical outcomes when performed by a medical professional with a high experience. Ideally, a randomized study would be performed to help answer the question as to whether or not the entry closure during FET without primary entry resection could be an alternative surgical strategy. False lumen thrombosis is a second goal of AAAD surgical repair. Although some reports demonstrated an acceptable risk of needing additional aortic arch surgery after AAAD, downstream reoperation should be generally avoided. Kimura et al. [17] mentioned that a patent false lumen was a significant risk factor of downstream reoperation and reported the achievement of 38% complete false lumen thrombosis. They strictly defined whole false lumen thrombosis from anastomotic site to the end of dissected aorta as complete false lumen thrombosis. The rate of false lumen thrombosis after TAR is reported as 23 57% in several reports [18 21]. In this study, we achieved a relatively high rate of 57% complete false lumen thrombosis. We defined thrombosed false lumen up to diaphragm level by delayed phase CT angiography as complete false thrombosis. On the basis of our definition, the rate for freedom from reoperation was significantly higher in patients with a thrombosed false lumen than in those with a patent false lumen (P = 0.007). The use of FET was also indicated for AAAD because of the advantages of false lumen thrombosis. Compared with the conventional ET series, FET effectively promoted the false lumen

6 572 Y. Inoue et al. / European Journal of Cardio-Thoracic Surgery thrombosis, with several reports noting false lumen thrombosis rates of % [2, 3, 14, 22, 23]. However, these reports used a definition of false lumen thrombosis that included persistent partial thrombosis, which was totally different from our definition. Therefore, a simple comparison of studies based on the rate of complete false lumen thrombosis is difficult. In addition, longterm outcome of the freedom from dissection-related downstream reoperation using FET was fewer and insufficient. We should also clarify the relationship between false lumen status and dissection-related downstream reoperation rates. In the future, FET may play an important role in improving outcomes based on false lumen status after clarification of these problems. In addition, spinal cord injury remains a critical postoperative complication. Although many authors have reported the utility of the FET so far, spinal cord injury occurred fairly frequently (2 13.8%) [3, 22, 23]. Some reports have described excellent results with no spinal cord injury; however, these reports did not include sufficient number of cases [2, 14]. FET with a branched graft was reported by the Uchida group in Japan. This study included one of the largest populations evaluated, especially in terms of patient number and length of follow-up. In-hospital mortality was 6%, and the persistent thrombosis rate was 100%; however, spinal cord injury occurred in 2% of cases [3]. A spinal cord injury is a devastating complication; therefore, Bartolomeo et al.[23] warned about an indication of FET and noted the importance of patient selection for this procedure. Shrestha et al.[24] also documented that FET should be shorter than 10 cm to prevent spinal cord complications. In our series, no postoperative spinal cord injuries were reported. When the traditional ET was implanted, an additional thoracic endovascular aortic repair (TEVAR) can be easily performed as a second stage operation. TAR followed by TEVAR is conceptually the same as a total arch with FET. A secondary TEVAR could wait until or after further examinations that included the detection of the artery feeding into the artery of Adamkiewicz to achieve accurate and safe TEVAR positioning. Murzi et al. [25] also mentioned the limited benefit of one-stage hybrid repair using FET for AAAD. As of this moment, the obvious benefit of FET compared with that of the conventional ET remains unclear in our opinion. FET might be a good alternative option in patients with a narrowed true lumen, or with an entry located at proximal descending aorta which cannot be removed. Thus, short FET has been currently applied for only limited cases in our institute. CONCLUSION In conclusion, surgical outcomes for AAAD with aggressive primary entry resection were satisfactory. In this series, the false lumen of thoracic aorta was completely thrombosed in a relatively high proportion of patients (57%). This achievement significantly reduced the need for downstream aortic reoperation relative to patients with a patent false lumen. Limitations The main limitation of this study was its retrospective approach to the analysis of long-term data and the single-centre analysis. Moreover, further studies comparing each technique are required to more precisely establish the best procedure for treating AAAD. Conflict of interest: none declared. REFERENCES [1] Lus F, Hagi C, Pichlmaler M. Elephant trunk procedure 27 years after Borst: what remains and what is new? Eur J Cardiothorac Surg 2011;40:1 11. [2] Sun L, Qi R, Zhu J, Liu Y, Zheng J. Total arch replacement combined with stented elephant trunk implantation: a new standard therapy for type A dissection involving repair of aortic arch? Circulation 2011;123: [3] Uchida N, Katayama A, Tamura K, Satoh M, Kuraoka M, Ishihara H. Frozen elephant trunk technique and partial remodeling for acute type A aortic dissection. Eur J Cardiothorac Surg 2011;40: [4] Minatoya K, Ogino H, Matsuda H, Sasaki H. Rapid establishment of cardiopulmonary bypass in repair of acute aortic dissection: improved results with double cannulation. Interact CardioVasc Thorac Surg 2008;7: [5] Watanuki H, Ogino H, Minatoya K, Matsuda H, Sasaki H, Ando M et al. Is emergency total arch replacement with a modified elephant trunk technique justified for acute type A aortic dissection? Ann Thorac Surg 2007; 84: [6] Kanda Y. Investigation of the freely-available easy-to-use software EZR (Easy R) for medical statistics. Bone Marrow Transplant 2013;48: [7] Rampoldi V, Trimarchi S, Eagle KA, Nienaber CA, Oh JK, Bossone E et al. Simple risk models to predict surgical mortality in acute type A aortic dissection: the International Registry of Acute Aortic Dissection score. Ann Thorac Surg 2007;83: [8] Unosawa S1, Hata M, Niino T, Shimura K, Shiono M. Prognosis of patients undergoing emergency surgery for type A acute aortic dissection without exclusion of the intimal tear. J Thorac Cardiovasc Surg 2013;146: [9] Miller DC, Stinson EB, Oyer PE, Rossiter SJ, Reitz BA, Griepp RB et al. Operative treatment of aortic dissections. Experience with 125 patients over a sixteen-year period. J Thorac Cardiovasc Surg 1979;78: [10] Urbanski PP, Siebel A, Zacher M, Hacker RW. Is extended aortic replacement in acute type A dissection justifiable? Ann Thorac Surg 2003;75: [11] Kazui T1, Washiyama N, Muhammad BA, Terada H, Yamashita K, Takinami M et al. Extended total arch replacement for acute type a aortic dissection: experience with seventy patients. J Thorac Cardiovasc Surg 2000;119: [12] Ogino H, Ando M, Sasaki H, Minatoya K. Total arch replacement using a stepwise distal anastomosis for arch aneurysms with distal extension. Eur J Cardiothorac Surg 2006;29: [13] El-Sayed A, Papadopoulos N, Detho F, Srndic E, Risteski P, Moritz A et al. Surgical repair for acute type A aortic dissection in octogenarians. Ann Thorac Surg 2015;99: [14] Roselli EE, Rafael A, Soltesz EG, Canale L, Lytle BW. Simplified frozen elephant trunk repair for acute DeBakey type I dissection. J Thorac Cardiovasc Surg 2013;145:S [15] Westaby S, Saito S, Katsumata T. Acute type A dissection: conservative methods provide consistently low mortality. Ann Thorac Surg 2002;73: [16] Bavaria JE, Brinster DR, Gorman RC, Woo YJ, Gleason T, Pochettino A. Advances in the treatment of acute type A dissection: an integrated approach. Ann Thorac Surg 2002;74: [17] Kimura N, Itoh S, Yuri K, Adachi K, Matsumoto H, Yamaguchi A et al. Reoperation for enlargement of the distal aorta after initial surgery for acute type A aortic dissection. J Thorac Cardiovasc Surg 2015;149:S91 8. [18] Halstead JC, Meier M, Etz C, Spielvogel D, Bodian C, Wurm M et al. The fate of the distal aorta after repair of acute type A aortic dissection. J Thorac Cardiovasc Surg 2007;133: [19] Fattori R, Bacchi-Reggiani L, Bertaccini P, Napoli G, Fusco F, Longo M et al. Evolution of aortic dissection after surgical repair. Am J Cardiol 2000;86: [20] Park KH, Lim C, Choi JH, Chung E, Choi SI, Chun EJ et al. Midterm change of descending aortic false lumen after repair of acute type I dissection. Ann Thorac Surg 2009;87: [21] Gariboldi V, Grisoli D, Kerbaul F, Giorgi R, Riberi A, Metras D et al. Long-term outcomes after repaired acute type A aortic dissections. Interact CardioVasc Thorac Surg 2007;6: [22] Pochettino A, Brinkman WT, Moeller P, Szeto WY, Moser W, Cornelius K et al. Antegrade thoracic stent grafting during repair of acute DeBakey I dissection prevents development of thoracoabdominal aortic aneurysms. Ann Thorac Surg 2009;88: [23] Bartolomeo R, Pantaleo A, Berretta P, Murana G, Castrovinci S, Cefarelli M et al. Frozen elephant trunk surgery in acute aortic dissection. J Thoac Cardiovasc Surg 2015;149:S [24] Shrestha M, Fleissner F, Ius F, Koigeldiyev N, Kaufeld T, Beckmann E et al. Total aortic arch replacement with frozen elephant trunk in acute type A

7 Y. Inoue et al. / European Journal of Cardio-Thoracic Surgery 573 aortic dissections: are we pushing the limits too far? Eur J Cardiothorac Surg 2015;47: [25] Murzi M, Gasbarri T, Glauber M. One stage hybrid approach for type A acute aortic dissection repair: just because we can, should we do. Interact CardioVasc Thorac Surg 2010;11:598 (ecomment). APPENDIX. CONFERENCE DISCUSSION Scan to your mobile or go to to search for the presentation on the EACTS library Dr R. Haaverstad (Bergen, Norway): The objective of this study was to analyse the efficacy of the surgical concept of aggressive primary entry resection in acute type A aortic dissection. The results show that 57% had occluded false lumen, and these had less downstream reoperations as seen in the conclusion. You have not applied the frozen elephant trunk technique or supplemented with a stent graft placed antegradely, but clearly missed it, as such methods are discussed extensively in the submitted manuscript. The patient material is heterogeneous, and the study is limited by its single centre recruitment. I have three questions for you. Firstly the hospital mortality was 8.4%. We like to give numbers on 30-day mortality or still within hospital. What was that? Dr Inoue: Actually, there was 6.9% in-hospital mortality in our institutions, and in addition, 1.5% patients died after they were discharged from our centre to the outside hospital. In short 8.4% is in-hospital death, but the 30-day mortality was less than 5%. Dr Haaverstad: So in total? Dr Inoue: Total 8.4% in total. Dr Haaverstad: In hospital. But 30 days later still a few died later or they didn t stay very long in hospital? Dr Inoue: I m sorry? Dr Haaverstad: Did they stay in the hospital for many weeks? Dr Inoue: Yes. Most of our patients were discharged home about 30 days after their operations. Dr Haaverstad: So most patients stay for a month? Dr Inoue: Yes. Dr Haaverstad: The second question is regarding the hemiarch technique. This is not necessarily a clearly defined surgical method, and many cardiac surgeons are in these kinds of patients pragmatic to ensure a short operation time by making the distal anastomosis with open distal aorta someplace at the border between the ascending aorta and arch. Can you explain your hemiarch technique, and were there variations in between surgeons? Dr Inoue: Mainly hemiarch replacement was just a reconstruction of the ascending aorta just below the innominate artery with the open distal technique. Hemiarch replacement included procedures which ascending aorta replacement and partial neck vessels reconstruction, we call as partial arch replacement. Dr Haaverstad: So most of them were a quite simple open arch repair? Dr Inoue: Yes, exactly. Dr Haaverstad: The third element I will ask is regarding the CT and cerebral dysfunction. Preoperatively cerebral dysfunction was seen in a number of patients, and 17% were classified as having coma. Permanent new neurological dysfunction postoperatively was found in 6.9% as defined by CT. Postoperatively 91% of the survivors had a CT after one week. So was cerebral CT done in all patients, both pre and postoperatively to support your certainty about the cerebral assessment regarding new peri and postoperative events? Dr Inoue: The answer is no. Actually, our institution is a centre specializing in heart, vascular, and cerebral disease, so that two-thirds of the patients referred from an outside clinic were already diagnosed as acute aortic dissections. So we try to transfer the diagnosed patient to the Operating room as fast as we can. Therefore routine pre-operative head CT scan was not performed. However, about 5% of patients had head CT scan. They usually had neurological symptoms due to the malperfusion syndrome and were referred from our neurological department. So the routine head CT scan was not performed preoperatively, and if the patient had residual symptoms, such as deep coma or hemiparesis, we checked the head CT postoperatively.