Preoperative predictive factors for mortality in acute type A aortic dissection: an institutional report on 217 consecutives cases
http://www.100md.com
《血管的通路杂志》
a Department of Cardiac Surgery, CHU, Grenoble, BP 217 University Hospital, Grenoble cedex 9, France
b Thoracic and Cardiovascular Intensive Care Unit, Grenoble University Hospital, Grenoble, France
c Department of Radiology, Grenoble University Hospital, Grenoble, France
Abstract
Surgical treatment of type A acute aortic dissection remains a challenge, especially in elderly patients or in patients with a critical preoperative status. We have retrospectively assessed our series over a 15-year period starting in 1990, including patients operated under cardiac massage for preoperative cardiac arrest occurring in the operating room. There were 217 patients (mean age, 61.5±13.5 years; 16 patients >80 years). Preoperative shock was noted in 21.7%, including 14 patients operated under cardiac massage. Operating procedures were: modified Bentall (31%), aortic tube (67.1%), other (1.9%), aortic arch procedure in 26.4%. Overall mortality rate was 19.8% with an exponential increase with age (50% over 80 years). Of 14 patients operated under cardiac massage, three have been discharged: one ventricular fibrillation due to an acute myocardial infarction and two among the 13 with acute aortic ruptures in cardiac arrest (one being a redo, the adhesions limiting the tamponade). Our results confirmed age and preoperative shock prior to surgery as risk factors, and the fact that operating on a patient under cardiac massage for cardiac arrest due to an aortic rupture is probably not a reasonable therapeutic choice.
Key Words: Acute; Aortic dissection; Cardiac arrest; Elderly
1. Introduction
Acute aortic dissection of the ascending aorta (AAD) is a life-threatening condition and a challenging clinical emergency. Although a mortality rate inferior to 10% was recently reported for surgically treated AAD [1,2], the average mortality rate remains high in many centers as recently reported in the IRAD study (25.1%) [3]. Despite improvements in surgical technique and perioperative care, some subgroups of patients remain at high surgical risk: elderly patients [4], patients with malperfusion syndrome [5], or with a critical preoperative status [3,6]. Indeed, many patients present a risk of sudden death before they can be taken to the operating room, due to coronary obstruction, tamponade or aortic rupture [7,8]. In this context, operating on a patient in cardiac arrest is a matter of debate, and no clear response to this question has ever been published. The goal of this paper was to assess the results and the predictors of hospital mortality on a consecutive series of 217 patients operated on in our institution since 1990.
2. Material and methods
We have performed a retrospective study on our database reviewing all AAD operated on in our department over a 15-year period, from 1 January 1990 to 31 December 2004. All iatrogenic dissections were excluded. There was no restriction for operation whatever the age or the preoperative status and we operated on patients even in the case of cardiac arrest, but only if it occurred after entering the operating room.
2.1. Patient recruitment
Over this 15-year period, ten patients died before any surgery was possible: five patients died before arrival in the operating room; five patients died during installation in the operating room. Finally, 217 patients were operated on (150 men, 67 women) and were included in our study. Two-thirds of the patients (70.5%) presented initially to an outside institution and two-thirds (69.2%), were directly admitted to the operating room.
2.2. Demographic and diagnostic method
The mean age was 61.5±13.5 years (range: 18–89.2) with 16 patients over 80 years of age. Most patients had multiple risk factors; the preoperative characteristics of the population are summarized in Table 1. Diagnosis was confirmed by transesophageal echocardiography (TEE) in 145 patients (66.8%), CT-scan in 28 patients (12.9%), TEE and CT-scan in 29 patients (13.4%), transthoracic echocardiography and CT-scan in 6 patients (2.8%), CT-scan and magnetic resonance imaging in 1 patient (0.5%), angiography in 3 patients (1.4%).
2.3. Preoperative status after installation in the operating room
Preoperative shock (systolic blood pressure <80 mmHg) was present in 47 patients (21.7%): tamponade in 37 patients (17.1%) and 16 patients (7.4%) required a preoperative drainage. Fourteen patients (6.5%) underwent a cardiac arrest and were operated on under cardiac massage. Preoperative neurological deficits were present in 28 patients (12.9%): hemiparesis or hemiplegia (13), paraparesis or paraplegia (4), syncope (11). Five patients were intubated before arrival (neurological status not assessable). Ischemic symptoms were present in 19 patients (8.8%): digestive (3), inferior limb (16), superior limb (1). Among 26 patients with ECG abnormalities, 6 were thrombolyzed before we took over their care.
2.4. Surgical technique
2.4.1. Technique of cardiopulmonary bypass (CPB)
The femoral artery was canulated before sternotomy. Axillary canulation was started in 2004 (4 cases). A femoro-femoral CPB was performed in 13 patients prior to sternotomy, either on an emergency basis in the case of patients presenting with a cardiac arrest (9 patients), or electively in the case of redo surgery. The mean aortic clamp time was 89.5±29.9 min and the mean CPB duration was 150.4±60.1 min. Patient core temperature was usually 28 °C for a single ascending aortic replacement and lower (18 °C) for more extensive procedures. The mean minimal core temperature was 26.7±4.2 °C. After removing the dissected ascending aorta, the remnant of the aortic wall was restored using a multiple U-stitch and biologic glue (GRF (Microval, Saint-Just-Malmont, France)) then Bioglue (Cryolife Inc, Kennesaw, GA; since 1999) before suturing the Dacron tube (using a felt strip placed on the adventitial side of the aortic anastomosis). A modified Bentall procedure was performed in the case of annuloaortic ectasia, aortic valve disease, when the intimal tear extended to the aortic root or in the case of a prosthetic valve in order to remove the remaining proximal aorta. An aortic arch procedure was performed when the intimal tear extended through the aortic arch, or in young patients when no intimal tear was found in the ascending aorta. For aortic arch procedures, we used a cerebral perfusion through the innominate artery (except in the case of axillary canulation) associated with a systemic hypothermia. Since 1999 we performed a CT-scan in the immediate postoperative period in order to detect a malperfusion syndrome.
2.5. Operative data
We had one fatal aortic rupture during sternotomy on an 89.2-year-old man. Thus, the aortic procedure was applied to 216 patients. A single aortic tube was performed in 145 patients (67.1%), a Bentall procedure in 67 patients (31%) and an aortic valve replacement with an aortic tube in 4 cases (1.9%). A Bentall operation was performed in the case of annuloaortic ectasia (47), prosthetic valve or aortic valve lesion (15), extension of intimal tear (4), hemostasis (1). An aortic arch procedure was performed in 57 patients (26.4%): hemi arch 51 patients (23.6%), total arch replacement 6 patients (2.8%). The patients were significantly younger in the case of Bentall procedure (52.5±14.3 vs. 65.4±11.6, P<0.0001) and older for aortic arch replacements (66.9 ± 10.6 vs. 59.5 ± 13.8, P=0.0003). A CABG was performed in 14 patients (6.5%) when a coronary ostium was found disrupted or in the case of myocardial ischemia.
2.6. Statistical analysis
Missing data were not defaulted to negative and results were based only on reported cases. Descriptive statistics were expressed as frequencies and percentages, mean± standard deviation, or as median and interquartile ranges. Univariate comparisons were made using an unpaired two-tailed t-test for continuous variables and the Chi-squared test for qualitative variables. Multivariate analysis was performed using logistic regression. Probability values <0.05 were considered as statistically significant.
3. Results
3.1. Postoperative results
3.1.1. Mortality
The 30-day and overall mortality rate were 16.6% and 19.8%, respectively. The causes of death were: peroperative (one aortic rupture, six unable to wean from CPB, two deaths during reoperation), multiple organ failure (18) with or without coma (15), digestive ischemia (5), cardiac failure (4), mediastinitis (1). Eleven of the above cases presented with preoperative cardiac arrest followed by resuscitation and cardiac massage. Among the 14 patients who presented with a cardiac arrest, three patients were discharged: one case sustained a ventricular fibrillation due to an acute myocardial infarction which resolved after cardiac massage and defibrillation, and two patients had acute aortic ruptures in cardiac arrest (one redo operation with pericardial adherences limiting the tamponade, and one aortic rupture with a rushed CPB installation who remained in a coma for two months with a residual neurological deficit). The other eleven patients presented also an aortic rupture with acute tamponade but died despite aggressive resuscitation and surgery. The univariate analysis (Table 2) showed a higher mortality for patients with cardiac arrest, an aortic arch replacement, and age over 80 years. The multivariate analysis showed that mortality was higher for patients over 70 years of age, after aortic arch procedures, or if they were operated on before 1999 (Table 3). Mortality according to age is shown in Fig. 1. After 1999, the hospital mortality rate in the 96 patients aged <80 years and without cardiac arrest was reduced to 7.3%.
3.1.2. Endovascular surgery
Since May 1998, endovascular techniques were applied to 24 patients among 118 (20.3%) either during the same hospitalization (14 patients) or after discharge (ten patients). Procedures were performed in order to treat malperfusion syndromes or to close a persistent intimal tear: 16 endovascular fenestrations, 10 embolizations for persistent intimal tear, and 14 endoprostheses with three aortic stents. Eight patients underwent multiple operations.
3.1.3. Length of stay
The median hospital stay was 16.5 days (interquartile: 12 days).
4. Comment
AAD must be operated urgently in order to reduce the risk of sudden death by aortic rupture and tamponade and the occurrence of malperfusion syndrome. Two factors may influence the results of surgical series: the delay before surgery, and the selection of patients for surgery. First, delaying surgery may lead to exclude patients with severe tamponade, major visceral malperfusion and stroke; thus bringing into play a degree of natural selection [7,9]. It has been reported [3] that patients whose surgical intervention was delayed for more than 24 h, had similar surgical results as patients considered hemodynamically stable (17.1% vs. 16.7%). Secondly, selecting patients artificially increases the overall surgical results but inevitably removes some of them from their best chance to survive, provided by surgery. In our institution we operated on each patient presenting with an AAD as soon as possible, whatever the age or the preoperative status, except in the case of a cardiac arrest occurring before entering the operating room. The assessment of this maximalist strategy allowed us to analyze the predictive factors of mortality in a cohort of consecutive AAD without selection by the surgical team. The results confirmed the high risk for elderly patients with an intriguing exponential increase towards a 50% mortality rate over 80 years, and the probable uselessness of operating on a patient in cardiac arrest due to aortic rupture. These results correlate with various previous studies showing that older age as well as hypotension, shock, and preoperative tamponade [3,6,10,11] are associated with a worse outcome [4,6,10]. The IRAD study [3] recently confirmed the higher mortality in hemodynamically unstable patients (31.4% vs. 16.7% for stable patients). Cardiac arrest with preoperative resuscitation is a very high risk factor for mortality [12]. In our series, only three patients among 14 presenting with a cardiac arrest survived and two of them had particular circumstances (redo operation, ventricular fibrillation). For other cases (complete rupture with massive tamponade), most of them died from coma and/or MOF. Indeed, in this context of aortic rupture, cardiac massage in a patient with a tamponade cannot be effective given the maximum 3 min delay before irreversible brain damage, too short a period for commencing CPB. Considering these results, we believe that operating on a patient suffering an AAD with a preoperative cardiac arrest is not recommended, except in the case of a ventricular arrhythmia or unless it occurs after complete installation on the operating table with a ready and available CPB circuit. The significant decrease of our perioperative mortality since 1999 is probably due to multiple technical factors, improvement of postoperative care, and early detection of malperfusion with endovascular treatment. The axillary canulation (recently introduced in our series) could have probably improved the results, reducing the occurrence of malperfusion syndrome and some neurological deficits [13]. Furthermore, it avoids iatrogenic intimal lesion due to the aortic clamp [9] and it allows to explore the aortic arch and to remove more pathologic aorta [14,15] performing an open anastomosis. However, surgeons have to be accustomed to this technique so as not to increase the time of canulation, particularly on unstable patients. In unstable patients, femoral artery canulation with rapid sternotomy, clamp and repair technique could remain the preferable technique in a selected group of patients, as it is safe and quick even if it may appear of historical interest to a part of the present cardiac surgical community.
4.1. Limitation of the study
This was a retrospective study but most of the data were prospectively included in our database. Some patients were certainly not referred to our center because of their advanced age or their too severe clinical status and this could have induced an indirect selection for our surgical cohort.
In conclusion, our results confirm the high risk factors of advanced age, although it should not systematically contraindicate the operation, and the probable uselessness of operating on a patient in cardiac arrest due to aortic rupture.
Acknowledgements
A special thanks to Dr Jean-Luc Bosson for his kind assistance in statistical analysis, and to Dr Pierre-Emmanuel Colles and Dr Serban Stoica, for copyediting the manuscript.
References
Westaby S, Saito S, Katsumata T. Acute type A dissection: conservative methods provide consistently low mortality. Ann Thorac Surg 2002; 73:707–713.
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:S1848–1852.
Trimarchi S, Nienaber CA, Rampoldi V, Myrmel T, Suzuki T, Mehta RH, Bossone E, Cooper JV, Smith DE, Menicanti L, Frigiola A, Oh JK, Deeb MG, Isselbacher EM, Eagle KA. International Registry of Acute Aortic Dissection Investigators. Contemporary results of surgery in acute type A aortic dissection: The International Registry of Acute Aortic Dissection experience. J Thorac Cardiovasc Surg 2005; 129:112–122.
Neri E, Toscano T, Massetti M, Capannini G, Carone E, Tucci E, Diciolla F, Scolletta S, Morello R, Sassi C. Operation for acute type A aortic dissection in octogenarians: is it justified J Thorac Cardiovasc Surg 2001; 121:259–267.
Deeb GM, Williams DM, Bolling SF, Quint LE, Monaghan H, Sievers J, Karavite D, Shea M. Surgical delay for acute type A dissection with malperfusion. Ann Thorac Surg 1997; 64:1669–1675.
Mehta RH, Suzuki T, Hagan PG, Bossone E, Gilon D, Llovet A, Maroto LC, Cooper JV, Smith DE, Armstrong WF, Nienaber CA, Eagle KA. International Registry of Acute Aortic Dissection (IRAD) investigators predicting death in patients with acute type A aortic dissection. Circulation 2002; 105:200–206.
Anagnostopoulos CE, Prabhakar MJ, Kittle CF. Aortic dissections and dissecting aneurysms. Am J Cardiol 1972; 30:263–273.
Hagan PG, Nienaber CA, Isselbacher EM, Bruckman D, Karavite DJ, Russman PL, Evangelista A, Fattori R, Suzuki T, Oh JK, Moore AG, Malouf JF, Pape LA, Gaca C, Sechtem U, Lenferink S, Deutsch HJ, Diedrichs H, Marcosy Robles J, Llovet A, Gilon D, Das SK, Armstrong WF, Deeb GM, Eagle KA. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. J Am Med Assoc 2000; 283:897–903.
Bachet J. Acute type A aortic dissection: can we dramatically reduce the surgical mortality Ann Thorac Surg 2002; 73:701–703.
Ehrlich MP, Ergin MA, McCullough JN, Lansman SL, Galla JD, Bodian CA, Apaydin A, Griepp RB. Results of immediate surgical treatment of all acute type A dissections. Circulation 2000; 102:III248–252.
Bayegan K, Domanovits H, Schillinger M, Ehrlich M, Sodeck G, Laggner AN. Acute type A aortic dissection: the prognostic impact of preoperative cardiac tamponade. Eur J Cardiothorac Surg 2001; 20:1194–1198.
Goossens D, Schepens M, Hamerlijnck R, Hartman M, Suttorp MJ, Koomen E, Vermeulen F. Predictors of hospital mortality in type A aortic dissections: a retrospective analysis of 148 consecutive surgical patients. Cardiovasc Surg 1998; 6:76–80.
Pasic M, Schubel J, Bauer M, Yankah C, Kuppe H, Weng YG, Hetzer R. Cannulation of the right axillary artery for surgery of acute type A aortic dissection. Eur J Cardiothorac Surg 2003; 24:231–235.
Nguyen B, Muller M, Kipfer B, Berdat P, Walpoth B, Althaus U, Carrel T. Different techniques of distal aortic repair in acute type A dissection: impact on late aortic morphology and reoperation. Eur J Cardiothorac Surg 1999; 15:496–500.
Kazui T, Yamashita K, Washiyama N, Terada H, Bashar AH, Suzuki T, Ohkura K. Impact of an aggressive surgical approach on surgical outcome in type A aortic dissection. Ann Thorac Surg 2002; 74:S1844–1847.(Olivier Chavanona,, Victor Costachea, Vi)
b Thoracic and Cardiovascular Intensive Care Unit, Grenoble University Hospital, Grenoble, France
c Department of Radiology, Grenoble University Hospital, Grenoble, France
Abstract
Surgical treatment of type A acute aortic dissection remains a challenge, especially in elderly patients or in patients with a critical preoperative status. We have retrospectively assessed our series over a 15-year period starting in 1990, including patients operated under cardiac massage for preoperative cardiac arrest occurring in the operating room. There were 217 patients (mean age, 61.5±13.5 years; 16 patients >80 years). Preoperative shock was noted in 21.7%, including 14 patients operated under cardiac massage. Operating procedures were: modified Bentall (31%), aortic tube (67.1%), other (1.9%), aortic arch procedure in 26.4%. Overall mortality rate was 19.8% with an exponential increase with age (50% over 80 years). Of 14 patients operated under cardiac massage, three have been discharged: one ventricular fibrillation due to an acute myocardial infarction and two among the 13 with acute aortic ruptures in cardiac arrest (one being a redo, the adhesions limiting the tamponade). Our results confirmed age and preoperative shock prior to surgery as risk factors, and the fact that operating on a patient under cardiac massage for cardiac arrest due to an aortic rupture is probably not a reasonable therapeutic choice.
Key Words: Acute; Aortic dissection; Cardiac arrest; Elderly
1. Introduction
Acute aortic dissection of the ascending aorta (AAD) is a life-threatening condition and a challenging clinical emergency. Although a mortality rate inferior to 10% was recently reported for surgically treated AAD [1,2], the average mortality rate remains high in many centers as recently reported in the IRAD study (25.1%) [3]. Despite improvements in surgical technique and perioperative care, some subgroups of patients remain at high surgical risk: elderly patients [4], patients with malperfusion syndrome [5], or with a critical preoperative status [3,6]. Indeed, many patients present a risk of sudden death before they can be taken to the operating room, due to coronary obstruction, tamponade or aortic rupture [7,8]. In this context, operating on a patient in cardiac arrest is a matter of debate, and no clear response to this question has ever been published. The goal of this paper was to assess the results and the predictors of hospital mortality on a consecutive series of 217 patients operated on in our institution since 1990.
2. Material and methods
We have performed a retrospective study on our database reviewing all AAD operated on in our department over a 15-year period, from 1 January 1990 to 31 December 2004. All iatrogenic dissections were excluded. There was no restriction for operation whatever the age or the preoperative status and we operated on patients even in the case of cardiac arrest, but only if it occurred after entering the operating room.
2.1. Patient recruitment
Over this 15-year period, ten patients died before any surgery was possible: five patients died before arrival in the operating room; five patients died during installation in the operating room. Finally, 217 patients were operated on (150 men, 67 women) and were included in our study. Two-thirds of the patients (70.5%) presented initially to an outside institution and two-thirds (69.2%), were directly admitted to the operating room.
2.2. Demographic and diagnostic method
The mean age was 61.5±13.5 years (range: 18–89.2) with 16 patients over 80 years of age. Most patients had multiple risk factors; the preoperative characteristics of the population are summarized in Table 1. Diagnosis was confirmed by transesophageal echocardiography (TEE) in 145 patients (66.8%), CT-scan in 28 patients (12.9%), TEE and CT-scan in 29 patients (13.4%), transthoracic echocardiography and CT-scan in 6 patients (2.8%), CT-scan and magnetic resonance imaging in 1 patient (0.5%), angiography in 3 patients (1.4%).
2.3. Preoperative status after installation in the operating room
Preoperative shock (systolic blood pressure <80 mmHg) was present in 47 patients (21.7%): tamponade in 37 patients (17.1%) and 16 patients (7.4%) required a preoperative drainage. Fourteen patients (6.5%) underwent a cardiac arrest and were operated on under cardiac massage. Preoperative neurological deficits were present in 28 patients (12.9%): hemiparesis or hemiplegia (13), paraparesis or paraplegia (4), syncope (11). Five patients were intubated before arrival (neurological status not assessable). Ischemic symptoms were present in 19 patients (8.8%): digestive (3), inferior limb (16), superior limb (1). Among 26 patients with ECG abnormalities, 6 were thrombolyzed before we took over their care.
2.4. Surgical technique
2.4.1. Technique of cardiopulmonary bypass (CPB)
The femoral artery was canulated before sternotomy. Axillary canulation was started in 2004 (4 cases). A femoro-femoral CPB was performed in 13 patients prior to sternotomy, either on an emergency basis in the case of patients presenting with a cardiac arrest (9 patients), or electively in the case of redo surgery. The mean aortic clamp time was 89.5±29.9 min and the mean CPB duration was 150.4±60.1 min. Patient core temperature was usually 28 °C for a single ascending aortic replacement and lower (18 °C) for more extensive procedures. The mean minimal core temperature was 26.7±4.2 °C. After removing the dissected ascending aorta, the remnant of the aortic wall was restored using a multiple U-stitch and biologic glue (GRF (Microval, Saint-Just-Malmont, France)) then Bioglue (Cryolife Inc, Kennesaw, GA; since 1999) before suturing the Dacron tube (using a felt strip placed on the adventitial side of the aortic anastomosis). A modified Bentall procedure was performed in the case of annuloaortic ectasia, aortic valve disease, when the intimal tear extended to the aortic root or in the case of a prosthetic valve in order to remove the remaining proximal aorta. An aortic arch procedure was performed when the intimal tear extended through the aortic arch, or in young patients when no intimal tear was found in the ascending aorta. For aortic arch procedures, we used a cerebral perfusion through the innominate artery (except in the case of axillary canulation) associated with a systemic hypothermia. Since 1999 we performed a CT-scan in the immediate postoperative period in order to detect a malperfusion syndrome.
2.5. Operative data
We had one fatal aortic rupture during sternotomy on an 89.2-year-old man. Thus, the aortic procedure was applied to 216 patients. A single aortic tube was performed in 145 patients (67.1%), a Bentall procedure in 67 patients (31%) and an aortic valve replacement with an aortic tube in 4 cases (1.9%). A Bentall operation was performed in the case of annuloaortic ectasia (47), prosthetic valve or aortic valve lesion (15), extension of intimal tear (4), hemostasis (1). An aortic arch procedure was performed in 57 patients (26.4%): hemi arch 51 patients (23.6%), total arch replacement 6 patients (2.8%). The patients were significantly younger in the case of Bentall procedure (52.5±14.3 vs. 65.4±11.6, P<0.0001) and older for aortic arch replacements (66.9 ± 10.6 vs. 59.5 ± 13.8, P=0.0003). A CABG was performed in 14 patients (6.5%) when a coronary ostium was found disrupted or in the case of myocardial ischemia.
2.6. Statistical analysis
Missing data were not defaulted to negative and results were based only on reported cases. Descriptive statistics were expressed as frequencies and percentages, mean± standard deviation, or as median and interquartile ranges. Univariate comparisons were made using an unpaired two-tailed t-test for continuous variables and the Chi-squared test for qualitative variables. Multivariate analysis was performed using logistic regression. Probability values <0.05 were considered as statistically significant.
3. Results
3.1. Postoperative results
3.1.1. Mortality
The 30-day and overall mortality rate were 16.6% and 19.8%, respectively. The causes of death were: peroperative (one aortic rupture, six unable to wean from CPB, two deaths during reoperation), multiple organ failure (18) with or without coma (15), digestive ischemia (5), cardiac failure (4), mediastinitis (1). Eleven of the above cases presented with preoperative cardiac arrest followed by resuscitation and cardiac massage. Among the 14 patients who presented with a cardiac arrest, three patients were discharged: one case sustained a ventricular fibrillation due to an acute myocardial infarction which resolved after cardiac massage and defibrillation, and two patients had acute aortic ruptures in cardiac arrest (one redo operation with pericardial adherences limiting the tamponade, and one aortic rupture with a rushed CPB installation who remained in a coma for two months with a residual neurological deficit). The other eleven patients presented also an aortic rupture with acute tamponade but died despite aggressive resuscitation and surgery. The univariate analysis (Table 2) showed a higher mortality for patients with cardiac arrest, an aortic arch replacement, and age over 80 years. The multivariate analysis showed that mortality was higher for patients over 70 years of age, after aortic arch procedures, or if they were operated on before 1999 (Table 3). Mortality according to age is shown in Fig. 1. After 1999, the hospital mortality rate in the 96 patients aged <80 years and without cardiac arrest was reduced to 7.3%.
3.1.2. Endovascular surgery
Since May 1998, endovascular techniques were applied to 24 patients among 118 (20.3%) either during the same hospitalization (14 patients) or after discharge (ten patients). Procedures were performed in order to treat malperfusion syndromes or to close a persistent intimal tear: 16 endovascular fenestrations, 10 embolizations for persistent intimal tear, and 14 endoprostheses with three aortic stents. Eight patients underwent multiple operations.
3.1.3. Length of stay
The median hospital stay was 16.5 days (interquartile: 12 days).
4. Comment
AAD must be operated urgently in order to reduce the risk of sudden death by aortic rupture and tamponade and the occurrence of malperfusion syndrome. Two factors may influence the results of surgical series: the delay before surgery, and the selection of patients for surgery. First, delaying surgery may lead to exclude patients with severe tamponade, major visceral malperfusion and stroke; thus bringing into play a degree of natural selection [7,9]. It has been reported [3] that patients whose surgical intervention was delayed for more than 24 h, had similar surgical results as patients considered hemodynamically stable (17.1% vs. 16.7%). Secondly, selecting patients artificially increases the overall surgical results but inevitably removes some of them from their best chance to survive, provided by surgery. In our institution we operated on each patient presenting with an AAD as soon as possible, whatever the age or the preoperative status, except in the case of a cardiac arrest occurring before entering the operating room. The assessment of this maximalist strategy allowed us to analyze the predictive factors of mortality in a cohort of consecutive AAD without selection by the surgical team. The results confirmed the high risk for elderly patients with an intriguing exponential increase towards a 50% mortality rate over 80 years, and the probable uselessness of operating on a patient in cardiac arrest due to aortic rupture. These results correlate with various previous studies showing that older age as well as hypotension, shock, and preoperative tamponade [3,6,10,11] are associated with a worse outcome [4,6,10]. The IRAD study [3] recently confirmed the higher mortality in hemodynamically unstable patients (31.4% vs. 16.7% for stable patients). Cardiac arrest with preoperative resuscitation is a very high risk factor for mortality [12]. In our series, only three patients among 14 presenting with a cardiac arrest survived and two of them had particular circumstances (redo operation, ventricular fibrillation). For other cases (complete rupture with massive tamponade), most of them died from coma and/or MOF. Indeed, in this context of aortic rupture, cardiac massage in a patient with a tamponade cannot be effective given the maximum 3 min delay before irreversible brain damage, too short a period for commencing CPB. Considering these results, we believe that operating on a patient suffering an AAD with a preoperative cardiac arrest is not recommended, except in the case of a ventricular arrhythmia or unless it occurs after complete installation on the operating table with a ready and available CPB circuit. The significant decrease of our perioperative mortality since 1999 is probably due to multiple technical factors, improvement of postoperative care, and early detection of malperfusion with endovascular treatment. The axillary canulation (recently introduced in our series) could have probably improved the results, reducing the occurrence of malperfusion syndrome and some neurological deficits [13]. Furthermore, it avoids iatrogenic intimal lesion due to the aortic clamp [9] and it allows to explore the aortic arch and to remove more pathologic aorta [14,15] performing an open anastomosis. However, surgeons have to be accustomed to this technique so as not to increase the time of canulation, particularly on unstable patients. In unstable patients, femoral artery canulation with rapid sternotomy, clamp and repair technique could remain the preferable technique in a selected group of patients, as it is safe and quick even if it may appear of historical interest to a part of the present cardiac surgical community.
4.1. Limitation of the study
This was a retrospective study but most of the data were prospectively included in our database. Some patients were certainly not referred to our center because of their advanced age or their too severe clinical status and this could have induced an indirect selection for our surgical cohort.
In conclusion, our results confirm the high risk factors of advanced age, although it should not systematically contraindicate the operation, and the probable uselessness of operating on a patient in cardiac arrest due to aortic rupture.
Acknowledgements
A special thanks to Dr Jean-Luc Bosson for his kind assistance in statistical analysis, and to Dr Pierre-Emmanuel Colles and Dr Serban Stoica, for copyediting the manuscript.
References
Westaby S, Saito S, Katsumata T. Acute type A dissection: conservative methods provide consistently low mortality. Ann Thorac Surg 2002; 73:707–713.
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:S1848–1852.
Trimarchi S, Nienaber CA, Rampoldi V, Myrmel T, Suzuki T, Mehta RH, Bossone E, Cooper JV, Smith DE, Menicanti L, Frigiola A, Oh JK, Deeb MG, Isselbacher EM, Eagle KA. International Registry of Acute Aortic Dissection Investigators. Contemporary results of surgery in acute type A aortic dissection: The International Registry of Acute Aortic Dissection experience. J Thorac Cardiovasc Surg 2005; 129:112–122.
Neri E, Toscano T, Massetti M, Capannini G, Carone E, Tucci E, Diciolla F, Scolletta S, Morello R, Sassi C. Operation for acute type A aortic dissection in octogenarians: is it justified J Thorac Cardiovasc Surg 2001; 121:259–267.
Deeb GM, Williams DM, Bolling SF, Quint LE, Monaghan H, Sievers J, Karavite D, Shea M. Surgical delay for acute type A dissection with malperfusion. Ann Thorac Surg 1997; 64:1669–1675.
Mehta RH, Suzuki T, Hagan PG, Bossone E, Gilon D, Llovet A, Maroto LC, Cooper JV, Smith DE, Armstrong WF, Nienaber CA, Eagle KA. International Registry of Acute Aortic Dissection (IRAD) investigators predicting death in patients with acute type A aortic dissection. Circulation 2002; 105:200–206.
Anagnostopoulos CE, Prabhakar MJ, Kittle CF. Aortic dissections and dissecting aneurysms. Am J Cardiol 1972; 30:263–273.
Hagan PG, Nienaber CA, Isselbacher EM, Bruckman D, Karavite DJ, Russman PL, Evangelista A, Fattori R, Suzuki T, Oh JK, Moore AG, Malouf JF, Pape LA, Gaca C, Sechtem U, Lenferink S, Deutsch HJ, Diedrichs H, Marcosy Robles J, Llovet A, Gilon D, Das SK, Armstrong WF, Deeb GM, Eagle KA. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. J Am Med Assoc 2000; 283:897–903.
Bachet J. Acute type A aortic dissection: can we dramatically reduce the surgical mortality Ann Thorac Surg 2002; 73:701–703.
Ehrlich MP, Ergin MA, McCullough JN, Lansman SL, Galla JD, Bodian CA, Apaydin A, Griepp RB. Results of immediate surgical treatment of all acute type A dissections. Circulation 2000; 102:III248–252.
Bayegan K, Domanovits H, Schillinger M, Ehrlich M, Sodeck G, Laggner AN. Acute type A aortic dissection: the prognostic impact of preoperative cardiac tamponade. Eur J Cardiothorac Surg 2001; 20:1194–1198.
Goossens D, Schepens M, Hamerlijnck R, Hartman M, Suttorp MJ, Koomen E, Vermeulen F. Predictors of hospital mortality in type A aortic dissections: a retrospective analysis of 148 consecutive surgical patients. Cardiovasc Surg 1998; 6:76–80.
Pasic M, Schubel J, Bauer M, Yankah C, Kuppe H, Weng YG, Hetzer R. Cannulation of the right axillary artery for surgery of acute type A aortic dissection. Eur J Cardiothorac Surg 2003; 24:231–235.
Nguyen B, Muller M, Kipfer B, Berdat P, Walpoth B, Althaus U, Carrel T. Different techniques of distal aortic repair in acute type A dissection: impact on late aortic morphology and reoperation. Eur J Cardiothorac Surg 1999; 15:496–500.
Kazui T, Yamashita K, Washiyama N, Terada H, Bashar AH, Suzuki T, Ohkura K. Impact of an aggressive surgical approach on surgical outcome in type A aortic dissection. Ann Thorac Surg 2002; 74:S1844–1847.(Olivier Chavanona,, Victor Costachea, Vi)