Immediate Perioperative Results and Early Survival in Patients Undergoing Aortic Repair for Thoracic Acute Aortic Dissection: Risk Factors Analysis and Surgical Implications

Abstract

Emergent surgical repair of thoracic acute aortic dissection (TAAD) aims to prevent potentially lethal complications including cardiac tamponade, neurological damage, acute aortic valve dysfunction, rupture of the aortic wall into the pericardial space, or myocardial infarction due to the dissection of the coronary ostia. Furthermore, the progression of the dissection involving peripheral arteries with, consequently, a possible preoperative multiple-organ malperfusion can lead to a drastic increase in operative risk. In fact, even with prompt surgical treatment, TAAD continues to be associated with an in-hospital mortality rate of 20–30%, and malperfusion of various organ systems can dramatically increase the operative mortality. From the analysis of the various pre- and perioperative risk factors, it is possible to evaluate the real operative risk and establish in which patients emergency surgery continues to offer a substantial prognostic benefit in comparison with medical therapy only and in which surgery, on the contrary, may not offer any prognostic advantage.

1. Introduction

Thoracic acute aortic dissection (TAAD) is a disease with a catastrophic impact on the patient’s life. Its incidence is about 30 cases/million/year; the natural history of this serious disease if surgically untreated, is associated with a mortality rate of 56% according to the International Registry of Acute Aortic Dissections (IRAD) [1], with a risk of death that increases by 1% per hour in the first 48 hours from the onset of symptoms [1, 2]. Despite numerous diagnostic innovations, development of new surgical techniques, and advances in postoperative therapies, that is, percutaneous tracheostomy, renal replacement therapy, it remains a disease with a high operative mortality. Emergent surgical repair of De Bakey type I and II TAAD has the aim to prevent potentially lethal complications including serious ischemic neurological damage, that is, stroke and coma, acute aortic valve dysfunction, complete rupture of the aortic wall into the pericardium, or myocardial infarction due to acute hypoperfusion of the coronary artery ostia. The involvement of the peripheral arteries due to the progression of the dissection and, consequently, the preoperative multiple-organ malperfusion can lead to a drastic increase in operative mortality. In fact, even with prompt surgical repair, TAAD continues to be associated with an in-hospital mortality rate of 20–30%; moreover, preoperative malperfusion of various organ systems can dramatically increase the operative mortality. In fact, preoperative malperfusion has been identified as one of the independent predictive factors of significantly increased operative risk and still remains the most evaluated clinical variable for the therapeutic management to be adopted in such patients. Other risk factors have also been analyzed in several registries and retrospective published analyses to evaluate in-hospital outcomes and to establish which TAAD patient populations are at the most risk of adverse early outcomes [3, 4, 5, 6, 7, 8].

The aim of the chapter is to analyze the most important risk factors influencing the postoperative outcomes, in light of both the data present in the literature and our long experience. From the analysis of the data, it is possible to identify patients for whom surgery is still confirmed to offer a notable prognostic benefit, or, on the contrary, patients for whom the very high perioperative risk may not lead to any prognostic benefit after surgery. On this way, we have evaluated the impact of perioperative risk factors and intraoperative variables on the immediate outcome, and at early and mid-term follow-up period. Further considerations will be made on the type of surgical strategy to be adopted in emergency setting, and the possible risk of late reoperation.

2. Our experience and early outcomes

Between January 2005 and December 2021, 393 patients (mean age 63.4 ± 12.5 years, range 16–88 years; males/females 286:107) underwent aortic repair for TAAD at the referred center for TAAD surgery at the Tor Vergata University Hospital.

Diagnosis of preoperative coronary arteries, visceral, or peripheral arterial malperfusion was based on clinical symptoms and/or imaging features, that is, absence or reduction of organ perfusion detected by computed tomography-scan angiography and/or increase of enzymes and creatinine serum levels, electrocardiographic changes suggestive of acute ischemia or myocardial infarction, alterations of cardiac contractile function detected at the trans-esophageal echocardiography. Malperfusion was classified as renal, in presence of impairment of renal function, that is, oliguria or anuria; as visceral, if there was evidence of abdominal tension and pain, intestinal dysfunction, increased serum levels of liver and/or pancreatic enzymes; as myocardial or coronary, in presence, CK-MB/CK total ratio > 10% and troponin I value above 20 ng/mL. In particular, the effect of these different types of malperfusion was accurately examined on the early and at 1-year outcomes, given their higher incidence in comparison with other risk factors, at the time of the admission at our center.

In the operating room, prior to surgical procedures, all patients were monitored by means of venous central cannulation, arterial cannulations, that is, both radial or radial and femoral arteries, measurements of corporeal temperature, that is, rectal, esophageal, or tympanic. Cerebral monitoring was performed with near-infrared spectroscopy (INVOS System, Somanetics Corp., Troy, MI, US). Trans-cranial Doppler was used to assess blood flow velocities in the anterior and middle cerebral arteries of the Willis circle during hypothermia and antegrade selective cerebral perfusion. Arterial access for cardiopulmonary by-pass in two-third of cases was through the right axillary artery, in the other one third of patients through the femoral artery; central cannulation was rarely performed.

In-hospital mortality included both intraoperative and postoperative mortality within 30 days after surgery. In this report, we have also collected data of patients up to 1 year of follow-up in order to evaluate the impact of the most important risk factors on short-term survival.

Statistical analysis was performed using Stat View 4.5 program (SAS Institute Inc., Abacus Concepts, Berkeley, CA, USA). To evaluate continuous variables and categorical variables, the Fisher’s exact test and the Chi-squared or Fisher’s exact tests were used. To identify independent predictors of in-hospital mortality, logistic regression analysis was performed. All the variables that reached statistical significance by univariate analysis at a P-value <0.1 were inserted into the multivariate regression model. Preoperative analyzed variables included gender, age, hypertension, diabetes mellitus, smoking status, body mass index, body surface area, previous cardiac surgery, left ventricular function, extent of the dissection, that is, De Bakey types I and II, presence and types of malperfusion, cardiac tamponade/pericardial effusion, and site of the entry tear. Intraoperative analyzed variables included the site of arterial cannulation, circulatory techniques to obtain brain perfusion, surgical times, whether there was a need for circulatory arrest, and type of operation, that is, ascending aorta replacement with or without the replacement of the hemi-arch, aortic root replacement with Bentall operation, the arch replacement, and the need of coronary artery bypass grafting. Short-term survival, including in-hospital mortality, was expressed as a mean of the values plus or minus 1 standard deviation. Survival analyses were computed using the Kaplan-Meier method; Mantel-Cox log-rank test was used to compare survival estimates between subgroups. Cox regression analysis was used to evaluate the influence of the analyzed variables on time to death. In particular, we have analyzed the impact of patient age groups ant the presence and type of malperfusion, separately and in combination on the short-term survival. The variables with a statistical significance by linear Cox analysis at a P-value <0.1 were entered into the Cox regression model. All P values less than 0.05 were considered statistically significant.

Results. Coronary malperfusion was present in 48 patients (12.2%), visceral malperfusion (renal with or without liver-mesenteric) in 90 (23%), and peripheral arterial malperfusion in 89 (22.6%) patients. Patients aged <65 years were 192 (group 1, 48.9%), aged 65–69 years, 60 (group 2, 15.3%), aged 70–74 years, 56 (group 3, 14.2%), with age 75–79 years, 58 (group 4, 14.7%), +80 years, 27 (group 5, 6.9%). Intraoperative death occurred in 39 patients (9.9%), and in-hospital mortality, including intraoperative, was 32.5% (n = 128 patients). Operative mortality including intraoperative deaths due to all postoperative malperfusions was 17.6% (69 cases /393).

Tables 1 and 2 show the risk factors and independent predictors of intraoperative and in-hospital mortality. The main causes of intraoperative deaths were the massive bleeding following aortic repair and heart failure (especially, of the right heart). Intraoperative mortality was strictly related, from a statistical point of view, with the greater length and complexity of the surgical intervention (Table 1).

	Univariate analysis		Multivariate analysis
Variables	P-value	Exp.(Coef)	95% CI	P-value
Cardiopulmonary by-pass time ↑ (284 vs. 169 min.)	<0.0001	1.02	1.01–1.05	<0.0001
T°C cardiopulmonary by-pass ↓ (26 vs. 27 °C)	0.036	1.34	1.02–1.76	0.034
Aortic cross-clamp time ↑ (141 vs. 97 min.)	<0.0001	0.99	0.97–1.00	0.179
Re-do operation	0.021	3.79	0.88–16.3	0.074
Cardiac tamponade/pericardial effusion	0.092	1.69	0.61–4.65	0.305
Coronary artery malperfusion	0.007	0.81	0.22–2.92	0.744
Visceral malperfusion	0.015	6.49	0.86–48.9	0.069
Peripheral arterial malperfusion	0.048	0.47	0.61–3.62	0.472
Arch replacement	0.0002	2.05	0.69–6.07	0.193
Coronary ostia re-implantation	0.096	2.68	0.93–7.75	0.067
CABG	0.021	1.97	0.31–12.4	0.469

Table 1.

Risk factors and independent predictors of intraoperative mortality (univariate and logistic regression analyses).

CABG: Coronary artery bypass grafting.

	Univariate analysis		Multivariate analysis
Variables	P-value	Exp. (Coef)	95% CI	P-value
Age ↑ (66 vs. 62 years)	0.005	1.06	1.02–1.09	0.0007
Age, groups 2–5	<0.05	0.59; 4.49; 7.13; 17.4	0.18–1.93; 1.44–14.1; 2.14–23.7; 3.84–79.5	0.382; 0.01; 0.0014; 0.0002
BMI ↑ (28 vs. 27)	0.024	1.03	0.97–1.11	0.342
De Bakey type-I dissection	0.088	1.82	0.89–4.76	0.089
Coronary artery malperfusion	0.002	4.45	0.70–8.47	0.018
Visceral malperfusion	0.003	5.06	0.79–32.4	0.087
Peripheral arterial malperfusion	0.021	0.27	0.39–1.86	0.184
Arch replacement	<0.0001	4.12	1.59–10.7	0.004
Cardiopulmonary by-pass time ↑ (223 vs. 162 min.)	<0.0001	1.01	1.00–1.02	0.0001
Cerebral perfusion time ↑ (42 vs. 32 min.)	0.023	0.99	0.98–1.01	0.269
Need for CABG	0.007	1.29	0.19–8.48	0.791
Postop. neurological dysfunction	0.004	0.96	0.09–1.03	0.05
Postop. dialysis requirement	<0.0001	7.95	3.68–31.0	<0.0001

Table 2.

Risk factors and independent predictors of operative (30-day) mortality (univariate and logistic regression analyses).

Groups of age: 2 = 65–69 years; 3 = 70–74 years; 4 = 75–79 years; 5 = +80 years. BMI: body mass index. CABG: coronary artery bypass grafting.

Higher age groups, preoperative malperfusions, and neurological (disabling stroke) and renal complications had a dramatic impact on the 30-day mortality risk (Table 2) and on the 1-year survival (Table 3). Specifically, in relation to the age of the patients, 1-year mortality was 29% for group 1, 38% for group 2, 32% for group 3, and 40% and 63% in groups 4 and 5, respectively.

			Regression analysis
Variables	Chi-square value	Exp. (Coef)	95% CI	P-value
Age, groups 2–5	0.76; 5.19; 11.8; 17.8	1.01; 3.04; 5.06; 13.3	1.00–1.01; 1.17–7.89; 2.01–12.7; 3.99–44.0	0.384; 0.022; 0.0006; <0.0001
Coronary artery malperfusion	0.98	0.99	0.35–2.81	0.983
Visceral malperfusion	0.01	1.03	0.25–4.28	0.971
Peripheral arterial malperfusion	0.021	0.27	0.39–1.86	0.184
Arch replacement	2.36	2.02	0.83–4.39	0.124
Coronary ostia reimplantation	0.22	0.84	0.41–1.71	0.635
Cardiopulmonary by-pass time ↑	13.9	1.01	1.00–1.01	0.0002
CABG	5.14	7.33	1.31–41.0	0.023
Postop. neurological dysfunction	0.17	0.21	0.04–1.23	0.683
Postop. dialysis requirement	40.1	18.3	7.44–45.0	<0.0001

Table 3.

Independent predictors of 1-year survival (Cox-regression analysis).

Groups of age: 2 = 65–69 years; 3 = 70–74 years; 4 = 75–79 years; 5 = +80 years. CABG: coronary artery bypass grafting.

At 1 year of follow-up, overall survival was 65.2 ± 2.4%. Figures 1–4 show the survival at 1 year of follow-up based on the age groups of the patients and the presence or absence of coronary, visceral, and peripheral arterial malperfusion, respectively.

Figure 1.

Short-term survival in relation to the division of patients by age group.

Figure 2.

Short-term survival in relation to presence or absence of preoperative coronary artery malperfusion.

Figure 3.

Short-term survival in relation to presence or absence of preoperative visceral malperfusion.

Figure 4.

Short-term survival in relation with presence or absence of preoperative peripheral arterial malperfusion.

3. Discussion and early clinical results

Various preoperative and perioperative variables have been identified over the years as risk factors and predictors of operative mortality, especially by the International Registry of Acute Aortic Dissection (IRAD) [1]: age > 70 years, cardiac tamponade, pulse deficit, hypotension, and different forms and localizations of malperfusion. The initially reported operative mortality of 32.5% has tended to decrease in subsequent years, but is still estimated to be high, between 17 and 26% [9], depending on the different clinical presentation of patients: in certain cases, in the presence of localized or generalized malperfusion, it even exceeds 80%. Among the perioperative risk factors, the most important to include as predictive are the increased operation time, the combined coronary artery bypass graft, the replacement of the aortic arch. Data from IRAD [2] showed that surgical mortality significantly increases with increased age, that is, 38% in patients ≥70 years vs. 26% of younger patients; data similar to what we observed: 29% in younger patients vs. ≥38% in older patients (P < 0.05). Given the 60% mortality with medical therapy alone, it has been proposed that, in general, a surgical approach should not be denied on the basis of advanced age alone. Again in agreement with the previous study, Hemli and collaborators [10] report from the IRAD database of 5553 patients observed in the period 1996–2018 an operative mortality of octogenarians similar to that observed in septuagenarians (25 vs. 21%), confirming again how age alone should not contraindicate the surgical indication. It should be noted, however, that only 68% of patients aged +80 years underwent surgery compared to septuagenarian patients (86%) (P < 0.0001), suggesting that the remaining 1/3 of non-operated eighty-year-old patients presented a preoperative clinical picture such as to be considered at prohibitive operative risk, for whom mortality would probably have reached or even exceeded that expected with medical treatment alone.

Similar indication rationale was proposed in the IRAD also with regards to the presence of malperfusion, especially visceral-mesenteric malperfusion, given that the mortality observed without intervention was 95 vs. 42% with aortic repair (P < 0.001) [9]. The mortality rate remains high because, as pointed out in literature [7], clinical presentation of the patients affected by TAAD in recent years has become increasingly serious, with a higher incidence of one or multi-organ malperfusion. In our previous publication, we found that the mortality rate in the presence of malperfusion was 47 vs. 23% without malperfusion (P < 0.0001) [11]. Augoustides and co-workers [12] on 221 patients affected by TAAD and undergoing aortic repair, reported a 8.3-fold difference on in-hospital mortality for no compared with any ischemia (3.1 vs. 25.8%, P = 0.0001). Ischemic presentation of more than one district accounted for 85.7% of all deaths. In the same way, we performed a retrospective analysis of data of our center with enough experience in the treatment of TAAD, paying particular attention to preoperative malperfusion involving specific organs, that is, myocardial, renal, and visceral, and the influence of this complication on the outcome in the short and in the medium term. In our experience, preoperative peripheral malperfusion of all types, that is, renal, visceral, others, and cardiac malperfusion, whether associated or not, occurred in 227 patients or in more than 57% of cases, and it correlated significantly with the postoperative development of malperfusive syndrome. The incidence of postoperative malperfusion was 20%, and it was the main cause of death intraoperatively and after surgery at 30 days (17.6%). Therefore, the surgery allowed the resolution of the malperfusion in about 2/3 of the cases, but in the other 1/3 of cases, proximal aortic replacement surgery does not provide a prognostic benefit in such patients. Peripheral malperfusion of any kind obviously correlates with the extent of the dissection [13]. In De Bakey type II TAAD, it can only be observed a coronary malperfusion and not distal. In fact, the minor extension of the type II acute dissection at the logistic regression analysis was identified as an independent protective factor of operative mortality.

Given the non-negligible incidence of preoperative onset of organ or multi-organ malperfusion and, consequently, the high mortality that this condition entail, in the last years, there is an open debate on the choice of therapeutic strategy to be adopted [14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24]. That is, if aortic surgical repair is always in any case promptly indicated, or if it may be better to carry out interventional procedures on the false lumen of the aorta to treat immediately, at least in part, the malperfusion syndrome and to improve the organs perfusion before surgery [25, 26, 27, 28]. Coselli et al. [29] emphasize that the primary purpose of the treatment, in the acute setting, is to save the patient, with an intervention on the proximal aorta that should be as short as possible, thus confirming the guidelines that place the replacement of the ascending aorta segment in class I of indication. Undoubtedly, it should be considered that the severity of preoperative malperfusion is not always well known, and that any delay in evaluation may increase the risk of death. Based on these clinical aspects, the authors, when the dissection affects the left main stem or the right coronary ostium, recommend to by-pass the left anterior descending and/or the right coronary artery to prevent myocardial ischemia or infarction. While, in presence of a dissection involving the superior mesenteric artery with a dynamic or static malperfusion, the authors suggest to do immediately endovascular aortic fenestration/stenting followed by surgical repair. If after mesenteric arterial reperfusion, patients develop acute respiratory failure, septic shock, multi-organ failure; in those cases, the authors suggest to wait for 2–4 weeks for a possible restoration of clinical conditions suitable for undergoing surgery. On the contrary, if isolated renal malperfusion is present, the authors agree for immediate surgery. Lawton et al. [30], Narayan et al. [31], Feier et al. [32], Yang et al. [26, 27], and their coworkers, analyzing data from over 1200 patients affected by TAAD, underline that, in patients with preoperative lactic acidosis and mesenteric ischemia, surgical treatment can lead to unacceptable mortality, with a ten-fold rise of mortality. Therefore, also in this study, the authors suggest the absolute necessity of a two-stage treatment, in order to restore in the first-stage intestinal adequate perfusion. Then, after reaching the improvement of the patient’s general condition, in the second stage, they confirm the indication for surgical repair. Furthermore, as we have assessed, it is important to consider both risk factors, that is, very advanced age and the concomitant presence of malperfusion. Vinholo et al. [33], in a recent review addressing which patients with TAAD surgery may not be indicated, underlines how the older age associated with frailty, preexisting neurological degenerative disease like dementia, malperfusion, and redo operation makes these patients at very high operative risk high or even prohibitive, also taking into consideration the type of postoperative complications that may occur, such as immobilization, severe chronic renal failure, prolonged intubation, and cognitive worsening. So much as to suggest that patients and family members should be well informed of the risks of surgery and suitable octogenarians selected for surgical treatment [34]. From the analysis of our data, as reported in Tables 4 and 5, we can see that at 1 year, the impact of age over 75 and over 80 associated with coronary or visceral malperfusion determines a dramatic reduction in survival, even to 16% only or 0% in patients over 80 associated with coronary or visceral malperfusion.

	Deaths	Censored	Survival (%)
No malperfusion/age, group 1	47	125	72.7
No malperfusion/age, group 2	17	33	66.0
No malperfusion/age, group 3	15	35	70.0
No malperfusion/age, group 4	19	32	62.7
No malperfusion/age, group 5	12	8	40.0
No malperfusion/age, all groups	110	233	67.9*
Malperfusion/age, group 1	9	11	55.0
Malperfusion/age, group 2	6	4	40.0
Malperfusion/age, group 3	3	3	50.0
Malperfusion/age, group 4	3	3	50.0
Malperfusion/age, group 5	5	1	16.7
Malperfusion/age, all groups	26	22	45.8*

Table 4.

Correlation between age groups of patients and coronary artery malperfusion on the 1-year actuarial survival (including in-hospital deaths).

^*

P = 0.012 (log rank, Mantel-Cox test).

Groups of age: group 1 = < 65 years; group 2 = 65–69 years; group 3 = 70–74 years; group 4 = 75–79 years; group 5 = +80 years.

	Deaths	Censored	Survival (%)
No malperfusion/age, group 1	36	107	74.8
No malperfusion/age, group 2	14	29	67.4
No malperfusion/age, group 3	9	35	79.5
No malperfusion/age, group 4	19	29	60.4
No malperfusion/age, group 5	15	9	37.5
No malperfusion/age, all groups	93	209	69.2**
Malperfusion/age, group 1	20	29	59.2
Malperfusion/age, group 2	9	8	47.1
Malperfusion/age, group 3	9	3	25.0
Malperfusion/age, group 4	3	6	66.7
Malperfusion/age, group 5	2	0	00.0
Malperfusion/age, all groups	43	46	51.7**

Table 5.

Correlation between age groups of patients and visceral malperfusion on the 1-year actuarial survival (including in-hospital deaths).

^**

P = 0.001 (log rank, Mantel-Cox test).

Groups of age: group 1 = < 65 years; group 2 = 65–69 years; group 3 = 70–74 years; group 4 = 75–79 years; group 5 = +80 years.

In Sievers’ study [35], in which the new TEM classification of TAAD has been proposed (T: type Stanford A, non-A non-B, and B; E: entry tear - E0 = tear non-visible, E1 = ascending aorta, E2 = arch, E3 = descending aorta - M: malperfusion - M0, M1 coronary, M2 supra-aortic vessels, M3 visceral-renal and/or lower extremity), it is reported an operative mortality of 40% for E2 and 22% for E0, respectively, vs. 14% for E1 (P = 0.023), highlighting a significantly higher risk when arch surgery is performed. Nappi et al. [36] in a multicenter registry including a total of 601 patients affected by TAAD undergoing aortic repair reported a higher rate of cerebrovascular complications after arch replacement (21.7 vs. 7.6%, P = 0.01). Rylski et al. [37] in a study conducted in 197 TAAD patients showed that, limiting the extent of surgery for type A aortic dissection to ascending aortic replacement was associated with low perioperative mortality (9.8% for isolated ascending aorta replacement; 21.6% for hemi-arch replacement; 28.6% for total arch replacement). Thus, aortic arch repair can be deferred because it can be performed electively with a lower mortality risk. Age > 80 years, malperfusion syndrome and arch replacement were identified as independent predictors of perioperative mortality (P-values ≤0.01). In fact, the guidelines on the treatment of TAAD do not routinely recommend the replacement of the aorta extended to the arch in all cases, but rather to be as conservative as possible given the severity of the condition of the patients who arrive in the operating room [38, 39]. In class I of indication, the main following indications are given in TAAD. (1) Aortic valve resuspension is recommended over its replacement. (2) In the presence of extensive destruction of the aortic root, of an aortic root aneurysm or a known genetic disorder, aortic root replacement with a mechanical or a biological valved conduit, that is, Bentall operation, is recommended. (3) An open distal anastomosis is recommended to improve survival and increase false-lumen thrombosis rates. (4) In patients without an intimal tear in the arch or a significant arch aneurysm, hemi-arch repair is recommended over more extensive arch replacement. Class 2b: in patients with dissection flap extending through the arch into the descending aorta, an extended aortic repair with antegrade stenting of the proximal segment of the descending aorta, that is, elephant trunk operation, may be considered to reduce the risk during the follow-up of distal aorta complications.

4. Discussion of the early and mid-term outcomes

In other ways, however, once the high risk of operative mortality has been overcome, short and medium-long term survival appears to be quite satisfactory: at 5 years in one previously performed study, we observed a late survival rate of 90.8% [11]. Cox regression and log-rank tests analyses identified that independent predictors of mid-term survival were age > 75 years (65 vs. 92%) (P-values <=0.05) and postoperative renal malperfusion (79 vs. 94%) (P-values <= 0.01). In another published study, we observed a 5-year late survival rate of 74%, with independent predictors of reduced survival being preoperative coronary malperfusion and greater extension toward the distal aorta of the De Bakey type I dissection (RR 5.78 and 5.37, respectively; P-values <0.05) [13]. Sievers et al. [35] reported a 2-year survival rate of 83% for Stanford A surgically treated dissections. Eranki et al. [34] on a total of 16,641 patients collected in a review analysis, reported a 5-year survival rate of 76% in the non-octogenarians patients vs. 54% in the octogenarians (P < 0.001). Freedom from aortic events appears to be conditioned by the extent of the aortic dissection, that is, type I De Bakey, by the presence of the false lumen with progression of the aneurysmal pathology, by the need for re-intervention due to progression of the aortic pathology at the level of the root and distal to the first aortic repair surgery. In our analysis, 5-year freedom from cardiac death and new vascular procedures to treat the distal aorta were 92 and 81%, respectively. Extension of the De Bakey type I TAAD into the thoracic-abdominal aorta was a predictor for the need for new vascular procedures (RR 1.66) [13]. Moreover, we have observed that patients in whom only replacement of the supra-junctional ascending aorta with or without hemi-arch was performed at the first operation, the incidence of reoperation on the proximal aorta, that is, Bentall re-do, during long-term follow-up, was significantly higher (13.2 vs. 2.9%, P < 0.05) [40].

5. Conclusions

Acute aortic dissection still is one of the most challenging diseases faced by cardiac surgeons, and despite preventative measures including early surgical referrals for patients, preoperative and postoperative care, and improved surgical techniques, in-hospital mortality remains high. Malperfusion syndromes and very advanced age, that is, > 75 and > 80 years, undoubtedly heavily influence the short-term outcome of these patients and are still today associated with a very high operative risk. Replacement of the proximal portion of the aorta is able to reduce the incidence of postoperative malperfusion in more than half of patients. However, in particular conditions, such as in the presence of an age over 80 years in association with concomitant presence of malperfusion syndromes and particular preoperative comorbidity conditions, surgical treatment, considering the observed risk of death and mortality within the first year of over 80%, should be weighed very carefully.

Conflict of interest

The authors declare no conflict of interest.