**3. Ensure a durable repair**

*Aortic Aneurysm and Aortic Dissection*

**2.1 Short-term mortality: statistics and causes**

mesenteric ischemia, and renal failure.

patient at the time of the surgery.

not be an operative contraindication.

the patient is unstable, in coma or over 80.

**2.2 Long-term mortality statistics and causes**

Type A aortic dissection (TAAD) is a serious pathology with high short-term

mortality rates. Indeed, series find a 50% mortality at 48 hours for nonoperated patients and an intrahospital mortality between 20 and 30% for operated

This high mortality rate is due to the great number of serious complications associated to the TAAD. The main mortality cause in the TAAD is acute aortic rupture [1]. Concerning the cardiac complications, we observe an aortic regurgitation in 40–75% [4, 5], a cardiac tamponade in 20%, and a myocardial infarction in 10–15%. These complications lead to congestive heart failure in 10% of cases. The other complications are neurological such as spinal ischemia, stroke and coma,

The analysis of short-term mortality shows that the characteristics of the patient (age, history of aortic valve replacement) and the preoperative complications of the TAAD (migrating chest pain, preoperative limb ischemia, hypotension, shock, cardiac tamponade) have more impact on the early survival than the type of surgical management [2]. These results demonstrate that even with optimal medical and surgical management, TAAD will remain a serious pathology with high mortality rate. These short-term mortality risk factors distinguish the patients in two categories at the time of the surgery: stable patients and unstable patients. Patients are defined as unstable in case of cardiac tamponade, myocardial ischemia, congestive heart failure, shock, cerebrovascular accident, coma, mesenteric ischemia, and acute renal failure. The latter having short-term mortality rate twice as high as stable patients (31.4 versus 16.7%) [2]. This distinction is important for the choice of the surgical technique, which should depend in part upon the stability of the

Management of patients with neurological complications at the onset of the dissection is still debated. To assess this issue, Tsukube presented the results of patients with coma on arrival [6]. They decided to operate immediately when coma was inferior to 5 hours. The surgical technique was a central repair performed under deep hypothermia with anterograde cerebral perfusion. For this group, intrahospital mortality was equal to 14%. Concerning the other patients, they were treated initially medically and in a second time surgically. Intrahospital mortality was equal to 67%. In terms of severity, the national institute of health stroke scale decreased significantly after the surgery in the immediate group. These results, confirmed by other series [7], show that coma, if managed immediately, should

Concerning the management of acute neurological deficit, Estrera showed that this complication, when managed surgically by central repair, was associated with an acceptable mortality rate (7 versus 100% of mortality for unoperated patients) [8]. Finally, surgery remains superior to optimal medical management even though

Even if the TAAD is an acute disease necessitating emergency treatment, this pathology presents an important long-term morbi-mortality. Thus, 10 years survival is between 50 and 70% [3, 9, 10], and 10 years re-operation rate is around

**2. Save the patient**

patients [1].

**90**

15% [11].

The main objective of the surgical treatment is to ensure the patient's survival. Thus, the replacement of the ascending aorta containing the primary tear and the re-establishment of the dominant flow through the true lumen prevent from acute aortic rupture and mostly correct vascular complications [13].

As seen before, the secondary objective of the surgical treatment is now to provide the best repair in order to prevent complications on the aortic valve and on the aorta. The challenge is to complete this preventing treatment without compromising the short-term survival. In this context, the European Society of Cardiology (ESC) provided recommendations upon the surgical treatment of the TAAD.

#### **3.1 Proximal segment of the ascending aorta**


Several techniques are suitable for aortic root replacement. In this situation, the aortic valve is the key factor.


**Figure 1.** *David procedure.*

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*Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair?*

Reimplantation valve sparing aortic root replacement (David procedure) consists of replacing the aortic root by composite graft without replacing the aortic valve. The coronary ostia are also reimplanted into the graft. This technique treats

Bentall procedure involves aortic valve replacement using an aortic valve prosthesis and an aortic root replacement using a composite graft. The coronary ostia

Whatever the extension of the repair, the distal anastomosis has to be performed

without aortic clamping, under circulatory arrest [15] (ESC 2014 class 1 recommendation). Neurological protection can be provided either by deep or moderate hypothermia. If deep hypothermia (under 22°C) has been performed for decades, recently, several studies such as El-Sayed have demonstrated that moderate hypothermia at 28°C associated with anterograde cerebral perfusion was able to ensure good neurological and visceral protection. This technique provides a low rate of postoperative neurological complications (6%) within a limited cardiopulmonary

In its guidelines, the European Society of Cardiology does not recommend a type of hypothermia [15]. Nevertheless, good results of moderate hypothermia in combination with anterograde cerebral perfusion should enable generalization of

The main question for this repair is to determine how far the repair has to be

○ The localization of the primary tear is performed by computed tomography (CT) or magnetic resonance imaging (MRI) but should be confirmed by peroperative findings. Thus, a cross clamped aorta does not allow the inspection of the aortic arch. For this reason, an open

○ The primary tear is localized in the aortic arch in 30% of the cases of TAAD [19]. In this case, the discussion is to identify patients who need a hemiarch replacement and those who need a complete aortic arch replacement, with or without a frozen elephant trunk. The analysis of the German Registry for Acute Aortic Dissection Type A (GERAADA) demonstrated that complete aortic arch replacement compared with hemiarch replacement neither increases the in-hospital mortality (25.7 vs. 18.7% *P* = 0.067) nor the onset of new neurological deficit (12.5 vs. 13.6% *P* = 0.78) [20]. Concerning the long-term follow-up, Di Eusenio did not show any statistical difference between total arch replacement and conservative arch management [21]. Thus, 7-year survival hazard ratio was equal to 1.001 (*P* = 0.8), and freedom from aortic reintervention was equal to 1.507 (*P* = 0.4). These results are similar to other studies on the subject [22]. As a conclusion, there is no difference concerning the short- and

Several factors will have an influence on the length of the reparation:

• Without aortic valve regurgitation, when the dissection does not involve the sinus of Valsalva, a simple aortic replacement with a composite graft tube can

*DOI: http://dx.doi.org/10.5772/intechopen.89298*

aortic regurgitation caused by annulus enlargement.

**3.2 Distal segment of the ascending aorta**

bypass time (183 +/− 56 minutes) [18].

• The localization of the primary tear

distal anastomosis is mandatory.

this approach.

performed.

be performed.

are reimplanted into the graft.

**Figure 2.** *Bentall procedure.*

*Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair? DOI: http://dx.doi.org/10.5772/intechopen.89298*

• Without aortic valve regurgitation, when the dissection does not involve the sinus of Valsalva, a simple aortic replacement with a composite graft tube can be performed.

Reimplantation valve sparing aortic root replacement (David procedure) consists of replacing the aortic root by composite graft without replacing the aortic valve. The coronary ostia are also reimplanted into the graft. This technique treats aortic regurgitation caused by annulus enlargement.

Bentall procedure involves aortic valve replacement using an aortic valve prosthesis and an aortic root replacement using a composite graft. The coronary ostia are reimplanted into the graft.

#### **3.2 Distal segment of the ascending aorta**

*Aortic Aneurysm and Aortic Dissection*

• In most cases, the valve is normal, and a simple regurgitation by annulus

surgery, regardless to an associated aortic insufficiency.

enlargement is observed. Then, an aortic valve sparing repair is recommended [15]. As shown by Farhat [16], aortic valve sparing repair procedure did not show higher short-term and mid-term mortality rate compared with conservative management and Bentall procedure (15.7% for inhospital mortality and 84.7% survival at 1 year after David procedure). If initially two techniques were applied, the remodeling technique as described by Yacoub and the

reimplantation technique described by David, the latter seems superior, mainly concerning the low reoperation rate [17] (**Figure 1**). Indeed, Leyh on a series of 30 patients found a 95 ± 5% freedom from reoperation in reimplantation group (David procedure) versus a 38 ± 23% remodeling group (Yacoub procedure) (*P* = 0.13). Yet, the cutoff for reintervention for secondary aortic insufficiency in the remodeling group was an annulus diameter over 27 mm at the time of the

• When the valve is pathological or in case of bicuspid aortic valve, an aortic valve

replacement using a Bentall technique is recommended (**Figure 2**).

**92**

**Figure 2.** *Bentall procedure.*

**Figure 1.** *David procedure.*

Whatever the extension of the repair, the distal anastomosis has to be performed without aortic clamping, under circulatory arrest [15] (ESC 2014 class 1 recommendation). Neurological protection can be provided either by deep or moderate hypothermia. If deep hypothermia (under 22°C) has been performed for decades, recently, several studies such as El-Sayed have demonstrated that moderate hypothermia at 28°C associated with anterograde cerebral perfusion was able to ensure good neurological and visceral protection. This technique provides a low rate of postoperative neurological complications (6%) within a limited cardiopulmonary bypass time (183 +/− 56 minutes) [18].

In its guidelines, the European Society of Cardiology does not recommend a type of hypothermia [15]. Nevertheless, good results of moderate hypothermia in combination with anterograde cerebral perfusion should enable generalization of this approach.

The main question for this repair is to determine how far the repair has to be performed.

Several factors will have an influence on the length of the reparation:

	- The localization of the primary tear is performed by computed tomography (CT) or magnetic resonance imaging (MRI) but should be confirmed by peroperative findings. Thus, a cross clamped aorta does not allow the inspection of the aortic arch. For this reason, an open distal anastomosis is mandatory.
	- The primary tear is localized in the aortic arch in 30% of the cases of TAAD [19]. In this case, the discussion is to identify patients who need a hemiarch replacement and those who need a complete aortic arch replacement, with or without a frozen elephant trunk. The analysis of the German Registry for Acute Aortic Dissection Type A (GERAADA) demonstrated that complete aortic arch replacement compared with hemiarch replacement neither increases the in-hospital mortality (25.7 vs. 18.7% *P* = 0.067) nor the onset of new neurological deficit (12.5 vs. 13.6% *P* = 0.78) [20]. Concerning the long-term follow-up, Di Eusenio did not show any statistical difference between total arch replacement and conservative arch management [21]. Thus, 7-year survival hazard ratio was equal to 1.001 (*P* = 0.8), and freedom from aortic reintervention was equal to 1.507 (*P* = 0.4). These results are similar to other studies on the subject [22]. As a conclusion, there is no difference concerning the short- and

long-term mortality or freedom from aortic reintervention. Thus, when the entry tear is localized in the aortic arch, a total aortic arch replacement could be reasonably performed.

	- Malperfusion syndrome has two origins: dynamic malperfusion secondary to compression of the true lumen by the false lumen and static malperfusion secondary to the extension of the dissection into the branch vessel. In many cases of malperfusion syndromes, these two mechanisms are combined (**Figure 3a**).

Concerning the management of the malperfusion syndrome, two strategies can be applied: performing digestive endovascular (fenestration or branch stenting) reperfusion before the ascending aorta repair or conversely performing ascending aorta repair first and treat only persistent malperfusion syndrome.

Regarding the first strategy, Yamashiro [23] showed upon a short series of 10 patients with visceral malperfusion, the advantages of performing visceral arterial branch bypass before central repair, and cardiopulmonary bypass. Others suggest performing a fenestration of the intimal flap rather than abdominal open surgery. Thus, Kamman [24] provide a patient-specific algorithm suggesting treating malperfusion syndrome first, waiting for the resolution of the malperfusion, and then performing central repair. This algorithm is based upon several studies which show the poor survival rate of TAAD complicated with malperfusion syndrome especially for patients with mesenteric ischemia requiring surgery (63.2 versus 23.8% *P* < 0.001) [25]. Nevertheless, this delaying strategy is questionable since it is associated with a high mortality rate. Thus, a large proportion of patients (33% in Patel series [26], 40% in Yang series [27]) die from aortic rupture or organ failure before the central repair.

#### **Figure 3.**

*(a) Type A aortic dissection complicated by malperfusion syndrome. (A) Preoperative CT: type A aortic dissection: low opacification of the true lumen with an impaired vascularization of the superior mesenteric artery. (B) Postoperative CT: type A aortic dissection treated by frozen elephant trunk: improvement of the mesenteric artery CT signal. (b) Frozen elephant trunk procedure: (A) frozen elephant trunk implantation scheme. E-vita open prothesis.*

**95**

history of TAAD.

*Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair?*

Concerning the second strategy, many authors [28, 29] propose to close the primary tear first. This approach, by redirecting the flow into the true lumen, decreases the need for latter revascularization, since in many cases the malperfusion syndrome is mainly dynamic. In Geirsson series [4], only 62.5% of patients with coronary malperfusion required coronary artery bypass and 42.9% of patients, with limb ischemia required distal revascularization after central repair. These

Regard to the central repair, a hybrid approach using the frozen elephant trunk technique or a two-time surgery extends the true lumen, decreases the false lumen diameter, the global aortic diameter, and creates a thrombosis of the false lumen [30] (**Figure 3b**). Thus, the vascular group of the European Association for Cardiac-Thoracic Surgery (EACTS) provided a IIa class recommendation for the use of frozen elephant trunk technique in TAAD with primary tear localized in the distal aortic arch or in the proximal half of the descending thoracic aorta in order to treat

As seen before, aneurysm formation is one of the main causes of excess mortality and reoperation in patients with history of TAAD [12]. Thus, preventing this complication is an important objective of the TAAD management. To answer this

• The frozen elephant trunk technique. This surgery includes a total arch replacement associated to a per-procedural stent delivery through the aortic true lumen. Concerning the prevention of aneurysm formation in the descending thoracic aorta, Uchida [32] proved the superiority of this technique compared with ascending aortic replacement or hemiarch replacement. Thus, he observed a decrease of late thoracic aorta event (95.7 *vs* 73.0% *P* = 0.01) mainly induced by thrombosis of the false lumen (100% of thrombosis in frozen elephant trunk group *vs* 29% in the other group). However, some limits persist concerning the frozen elephant trunk technique: this surgery is demanding, emphasize the operative time, and require experimented surgeon. Moreover, some series have shown an increasing of

• A two-time surgery including a complete aortic arch replacement followed by the implantation of an endoprothesis in the descending thoracic aorta through a femoral artery. A matter of debate is the moment of the second intervention. Most teams perform MRI or CT control till reaching aortic diameter superior to 55 mm. This approach can be discussed. Indeed, as demonstrated by the *Society of Thoracic Surgeons Endovascular Surgery Task Force,* intimal flap fibrosis appears over time [21]. This fibrosis jeopardizes endovascular treatment and frequently leads to open surgery [34]. Moreover, actual guidelines for aortic aneurysm treatment are the same whatever the etiology: at the descending thoracic aorta: a maximal diameter superior to 60 mm for open surgery and 55 mm for endovascular treatment [35]. Unfortunately, this cutoff is not suitable to dissected aorta which is a fragilized vessel. For example, Kimura found a median diameter before aortic rupture at 56 mm [36] in patient with

Yet, performing a hybrid surgery in the descending thoracic aorta does not prevent in all cases from aneurysm formation. At the thoracic level, false lumen

*DOI: http://dx.doi.org/10.5772/intechopen.89298*

results were similar in Charlton's study [5].

or prevent a malperfusion syndrome [31].

neurological complications [33].

• The prevention of aneurysm formation

issue, two surgical techniques using hybrid surgery exist:

#### *Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair? DOI: http://dx.doi.org/10.5772/intechopen.89298*

Concerning the second strategy, many authors [28, 29] propose to close the primary tear first. This approach, by redirecting the flow into the true lumen, decreases the need for latter revascularization, since in many cases the malperfusion syndrome is mainly dynamic. In Geirsson series [4], only 62.5% of patients with coronary malperfusion required coronary artery bypass and 42.9% of patients, with limb ischemia required distal revascularization after central repair. These results were similar in Charlton's study [5].

Regard to the central repair, a hybrid approach using the frozen elephant trunk technique or a two-time surgery extends the true lumen, decreases the false lumen diameter, the global aortic diameter, and creates a thrombosis of the false lumen [30] (**Figure 3b**). Thus, the vascular group of the European Association for Cardiac-Thoracic Surgery (EACTS) provided a IIa class recommendation for the use of frozen elephant trunk technique in TAAD with primary tear localized in the distal aortic arch or in the proximal half of the descending thoracic aorta in order to treat or prevent a malperfusion syndrome [31].

• The prevention of aneurysm formation

As seen before, aneurysm formation is one of the main causes of excess mortality and reoperation in patients with history of TAAD [12]. Thus, preventing this complication is an important objective of the TAAD management. To answer this issue, two surgical techniques using hybrid surgery exist:


Yet, performing a hybrid surgery in the descending thoracic aorta does not prevent in all cases from aneurysm formation. At the thoracic level, false lumen

*Aortic Aneurysm and Aortic Dissection*

approach.

before the central repair.

could be reasonably performed.

• The presence of a malperfusion syndrome

combined (**Figure 3a**).

long-term mortality or freedom from aortic reintervention. Thus, when the entry tear is localized in the aortic arch, a total aortic arch replacement

○ In some cases, the primary tear is localized in the descending thoracic aorta, and the ascending aorta is affected by a retrograde dissection. A hybrid surgery using a frozen elephant trunk technique is the best way to manage this situation. A two-time procedure can also be performed by the realization of a complete arch repair followed by the implantation of an endoprosthesis in the descending thoracic aorta through a femoral

○ Malperfusion syndrome has two origins: dynamic malperfusion secondary to compression of the true lumen by the false lumen and static malperfusion secondary to the extension of the dissection into the branch vessel. In many cases of malperfusion syndromes, these two mechanisms are

Concerning the management of the malperfusion syndrome, two strategies can be applied: performing digestive endovascular (fenestration or branch stenting) reperfusion before the ascending aorta repair or conversely performing ascending

Regarding the first strategy, Yamashiro [23] showed upon a short series of 10 patients with visceral malperfusion, the advantages of performing visceral arterial branch bypass before central repair, and cardiopulmonary bypass. Others suggest performing a fenestration of the intimal flap rather than abdominal open surgery. Thus, Kamman [24] provide a patient-specific algorithm suggesting treating malperfusion syndrome first, waiting for the resolution of the malperfusion, and then performing central repair. This algorithm is based upon several studies which show the poor survival rate of TAAD complicated with malperfusion syndrome especially for patients with mesenteric ischemia requiring surgery (63.2 versus 23.8% *P* < 0.001) [25]. Nevertheless, this delaying strategy is questionable since it is associated with a high mortality rate. Thus, a large proportion of patients (33% in Patel series [26], 40% in Yang series [27]) die from aortic rupture or organ failure

*(a) Type A aortic dissection complicated by malperfusion syndrome. (A) Preoperative CT: type A aortic dissection: low opacification of the true lumen with an impaired vascularization of the superior mesenteric artery. (B) Postoperative CT: type A aortic dissection treated by frozen elephant trunk: improvement of the mesenteric artery CT signal. (b) Frozen elephant trunk procedure: (A) frozen elephant trunk implantation* 

aorta repair first and treat only persistent malperfusion syndrome.

**94**

**Figure 3.**

*scheme. E-vita open prothesis.*

#### **Figure 4.**

*Aneurysmal evolution after frozen elephant trunk procedure. (A) Preoperative CT of a type A aortic dissection. (B) Postoperative CT after frozen elephant trunk implantation (E-vita open prothesis). (C and D) 5 years postoperative. CT: Aneurysmal evolution on the descending aorta at the thoraco abdominal junction despite the thrombosis of the false lumen at the thoracic stage. (E) CT post fenestrated aortic stent graft implantation.*

**97**

**Figure 5.**

*Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair?*

thrombosis induces inflammatory reaction inside the aortic wall. This inflammation is problematic; indeed, several studies have demonstrated the role of this inflammatory state in aneurysm progression, particularly through the production of metalloproteases and proinflammatory cytokines [37], these two elements leading to neo-angiogenesis and destruction of the extracellular matrix in the aortic wall. At the abdominal level, aortic aneurysm is frequently observed after hybrid surgery of dissected thoracic aorta (**Figure 4**). Several factors explain this evolution: a patent false lumen at this level, the modification of the aortic wall shear stress, the creation of a helicoidal flow downstream the endoprosthesis [38]

To prevent this complication, Matalanis [39] proposes to perform a total aortic repair combining surgical ascending aorta repair and endovascular treatment of the descending aorta. This last treatment includes the deployment of a covered stent graft in the proximal part of descending aorta and rupture of the intimal flap for the last part of the aorta (Sabilize approach). This rupture is performed through the deployment and the dilatation under balloon of uncovered stent graft. Thus, a unique aortic channel is created, avoiding aneurysmal evolution of the false channel. Even if this technique seems appealing, reservations with regards persist. Indeed, according to Matalanis study, this technique provides specific complications such as additional visceral stenting (40% of cases), iliac stenting (20% of cases), and reintervention for endoleak (20% of cases). Moreover, only 53% had a complete false lumen thrombosis. Finally, as yet there is no long-term follow-up concerning

As we see, if surgical solutions exist, the prevention of aneurysm formation in the descending thoracic aorta using hybrid surgery is still discussed. Thus, the European Association for Cardio-Thoracic surgery expresses only a class IIb recom-

In this context, this surgery must be provided to selected patients. In order to identify which patients should be considered for a frozen elephant trunk implantation, several studies have searched for risk factor of aneurysm formation after TAAD [41, 42]. In 2003, Yeh from a series of 144 patients operated for TAAD

*4D phase-contrast MRI after treatment of a type A aortic dissection by frozen elephant trunk.*

the aortic dimension (median follow-up: 26 month) [40].

mendation with a C level of evidence for this indication.

*DOI: http://dx.doi.org/10.5772/intechopen.89298*

(**Figure 5**).

*Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair? DOI: http://dx.doi.org/10.5772/intechopen.89298*

thrombosis induces inflammatory reaction inside the aortic wall. This inflammation is problematic; indeed, several studies have demonstrated the role of this inflammatory state in aneurysm progression, particularly through the production of metalloproteases and proinflammatory cytokines [37], these two elements leading to neo-angiogenesis and destruction of the extracellular matrix in the aortic wall. At the abdominal level, aortic aneurysm is frequently observed after hybrid surgery of dissected thoracic aorta (**Figure 4**). Several factors explain this evolution: a patent false lumen at this level, the modification of the aortic wall shear stress, the creation of a helicoidal flow downstream the endoprosthesis [38] (**Figure 5**).

To prevent this complication, Matalanis [39] proposes to perform a total aortic repair combining surgical ascending aorta repair and endovascular treatment of the descending aorta. This last treatment includes the deployment of a covered stent graft in the proximal part of descending aorta and rupture of the intimal flap for the last part of the aorta (Sabilize approach). This rupture is performed through the deployment and the dilatation under balloon of uncovered stent graft. Thus, a unique aortic channel is created, avoiding aneurysmal evolution of the false channel. Even if this technique seems appealing, reservations with regards persist. Indeed, according to Matalanis study, this technique provides specific complications such as additional visceral stenting (40% of cases), iliac stenting (20% of cases), and reintervention for endoleak (20% of cases). Moreover, only 53% had a complete false lumen thrombosis. Finally, as yet there is no long-term follow-up concerning the aortic dimension (median follow-up: 26 month) [40].

As we see, if surgical solutions exist, the prevention of aneurysm formation in the descending thoracic aorta using hybrid surgery is still discussed. Thus, the European Association for Cardio-Thoracic surgery expresses only a class IIb recommendation with a C level of evidence for this indication.

In this context, this surgery must be provided to selected patients. In order to identify which patients should be considered for a frozen elephant trunk implantation, several studies have searched for risk factor of aneurysm formation after TAAD [41, 42]. In 2003, Yeh from a series of 144 patients operated for TAAD

*Aortic Aneurysm and Aortic Dissection*

**96**

**Figure 4.**

*implantation.*

*Aneurysmal evolution after frozen elephant trunk procedure. (A) Preoperative CT of a type A aortic dissection. (B) Postoperative CT after frozen elephant trunk implantation (E-vita open prothesis). (C and D) 5 years postoperative. CT: Aneurysmal evolution on the descending aorta at the thoraco abdominal junction despite the thrombosis of the false lumen at the thoracic stage. (E) CT post fenestrated aortic stent graft* 

with a 3 years follow-up showed that preoperative isthmic diameter enlargement (OR = 1.11, *P* = 0.0025) and patent false lumen (OR = 13.28, *P* = 0.002) were risk factors for aneurysmal evolution [28]. Kirsch, with a longer follow-up, found a 56.1 ± 9.4% rate of reinterventions at 15 years. About 84.2% of these reinterventions were the consequence of aneurysmal evolution. After multivariate analysis, risk factors appeared to be youth, recent intervention, and type 1 dissection. Finally, the literature analysis identifies patent false lumen, preoperative isthmus diameter enlargement, preoperative descending thoracic aorta diameter enlargement over 40 mm, and long-term uncontrolled blood pressure as risk factors for descending thoracic aorta aneurysm.

Performing a descending thoracic aorta treatment by hybrid approach at the initial phase, in selected patient, could be a solution for reduction of excess mortality and morbidity of this population. Thus, patients presenting a TAAD with a descending thoracic aorta diameter superior to 40 mm could benefit from a hybrid treatment of this aortic segment.

Finally, in case of chronic dissection with aneurismal evolution reaching both ascending and thoracic descending aorta, two techniques can be discussed: a two-stage technique combining surgery on the ascending aorta via sternotomy and endovascular treatment of the descending aorta or a one-stage technique via bilateral thoracotomy (clamshell incision), with right subclavian and femoral perfusions and deep hypothermic circulatory arrest, allowing the replacement of the ascending, arch and descending aorta at different levels as described by Kouchoukos [43]. This last procedure provides low complications rates (mortality: 2.5%, reoperation for bleeding: 7.5%, neurological event: 2.4%) and a freedom from reoperation rate at 10 years equal to 84.4%.

It is important to remind that this preventive treatment has to be integrated in a global management, involving medical and surgical care, including genetic screening and strict blood pressure control. Eggebrecht demonstrated that a large part of patients with aortic dissection history (40%) had resistant hypertension despite multiple drug therapy [44], especially when patients were young and obese. These results underline the necessity to refer these patients to specialists in hypertension. Furthermore, the large number of loss of view in series [19] demonstrates that TAAD is still considered merely as an acute disease. This vision is mistaken: aortic dissection is a chronic disease, beginning in an acute way, reaching the entire aorta and requiring medical and surgical long-term follow-up.

Visualization of the aortic flow through the streamline technique: Presence of a helicoidal flow downstream the endoprosthesis.

• The surgeon's experience

The surgeon's experience is a key element of the surgical management. TAAD is a challenging pathology requiring complex surgical techniques such as aortic valve sparing and frozen elephant trunk implantation. If the operator is not familiar with aortic valve sparing repair, it is suitable to perform a Bentall intervention instead. In the same idea, performing an arch replacement followed by an endoprosthesis implantation in the descending aorta can be preferred to a frozen elephant trunk approach.

#### **3.3 Type B aortic dissection with arch extension**

Type B aortic dissection (TBAD) with retrograde arch extension occurs in 25% of cases of TBAD [45]. However, even if this situation is not rare, there are no recommendations concerning the management of this case.

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trunk.

**4. Conclusion**

**Author details**

*Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair?*

Tsai [46] analyzed the International Registry of Acute Dissection Database. He found that patients with TBAD and arch extension received the same treatment than pure TBAD: medical treatment when there was no complication and endovascular or surgical treatment in case of complication. Open surgery on the aortic arch was performed in case of complication related with arch pathology: aortic arch expansion, aortic arch rupture, or malperfusion in the arch vessels. In comparison with TBAD without arch extension, mortality rates between the two groups were

When surgery on the aortic arch is necessary, total arch replacement with frozen

elephant trunk seems to be the best option. Indeed, this technique enables the aortic arch to be replaced and the primary tear to be closed when it is situated in the proximal part of the thoracic descending aorta. Moreover, an endoprothesis can be deployed in a second time if the primary tear is not occluded by the frozen elephant

Finally, TBAD with arch extension should be treated as TBAD. Aortic arch replacement combined with frozen elephant trunk should be performed in case of

TAAD is a serious condition requiring emergency surgical treatment. If saving the patient remains the main objective of the surgery, long-term follow-up leads us to improve initial surgical treatment, mainly to prevent long-term aneurysmal evolution, either on the aortic root or on the descending thoracic aorta. Concerning the proximal segment, guidelines are clear: aortic root has to be replaced if the sinuses of Valsalva are involved by the dissection. Concerning the descending thoracic aorta, there is still no consensus, but studies show that hybrid surgery should be performed in case of malperfusion syndrome and when patients presents high risk

Benoit Cosset, Sarah Abdellaoui, Hugo Huvelle, Amine Fikani and Fadi Farhat\* Department of Cardiovascular Surgery B, Hospital Louis Pradel, Hospices Civils de

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*DOI: http://dx.doi.org/10.5772/intechopen.89298*

similar (short-term: *P* = 0.61, long-term: *P* = 0.82).

complication related with an arch pathology.

factors for aneurysmal evolution.

Lyon, Université Lyon 1, Lyon, France

provided the original work is properly cited.

\*Address all correspondence to: fadi.farhat@chu-lyon.fr

*Extensive Repair in Type A Aortic Dissection: To Save the Patient or to Ensure a Durable Repair? DOI: http://dx.doi.org/10.5772/intechopen.89298*

Tsai [46] analyzed the International Registry of Acute Dissection Database. He found that patients with TBAD and arch extension received the same treatment than pure TBAD: medical treatment when there was no complication and endovascular or surgical treatment in case of complication. Open surgery on the aortic arch was performed in case of complication related with arch pathology: aortic arch expansion, aortic arch rupture, or malperfusion in the arch vessels. In comparison with TBAD without arch extension, mortality rates between the two groups were similar (short-term: *P* = 0.61, long-term: *P* = 0.82).

When surgery on the aortic arch is necessary, total arch replacement with frozen elephant trunk seems to be the best option. Indeed, this technique enables the aortic arch to be replaced and the primary tear to be closed when it is situated in the proximal part of the thoracic descending aorta. Moreover, an endoprothesis can be deployed in a second time if the primary tear is not occluded by the frozen elephant trunk.

Finally, TBAD with arch extension should be treated as TBAD. Aortic arch replacement combined with frozen elephant trunk should be performed in case of complication related with an arch pathology.
