**12. Hemi-arch or full arch**

When the aortic arch is examined during hypothermic circulatory arrest to look for intimal or re-entry tears, a decision is made whether an aortic arch replacement has to be done. The pre-operative CT aortogram helps in localising the dissection and also on deciding the placement of the aortic cross clamp. If the tear is in the ascending aorta or start of the aortic curvature, then hemi-arch replacement is required. If the dissection is extends more distally, a total aortic arch repair should be performed (**Figure 11a**, **b**).

**73**

*Current and Future Management Strategies of Type A Aortic Dissection*

5.Descending thoracic aorta diameter more than 35 mm

aggressive approach to reduce the rate of interventions.

hypothermic circulatory arrest can be dramatically increased.

A study of 188 patients by Kim et al. [44] showed that 5 year survival was lower in patients with total arch replacement compared to patients who had hemi-arch repair (65.8% vs. 83.2%, p = 0.013). Neurological complications were higher in total arch repair group compared to hemi-arch (56.9% vs. 24.8%, p < 0.001).There was a direct correlation between patent false lumen in aortic arch or descending aorta and re-intervention. The German registry for TAAD showed no significant difference in peri-operative outcomes between both groups [45]. This group suggested a more

*Total arch replacement. (a, b) Debranching of aortic arch vessels – innominate , carotid artery and left* 

The immediate post-operative results have improved post type A Aortic dissection repair. However, long-term results are guarded by the need for aortic re-interventions due to residual dissection and patent false lumen extending into descending thoracic aorta [46]. The frozen elephant trunk technique involves total arch replacement and per-procedural deployment of stent through the true aortic lumen. It is more complex and takes more time. However, there is 90% chance of false lumen obliteration and reduced rates of re-intervention and improved longterm survival [47]. Uchida et al. [47] showed improved survival in the FET group at 5 years (95.3% vs. 69%, p = 0.03) and 100% thrombosis of false lumen in FET group compared to 29% patent false lumen in the non-FET group. However, both groups had similar operative mortality. Caution should be exercised that it should be done in high volume centres and by experienced suregons.as the total duration of

Deployment of stent in the descending thoracic aorta has its drawbacks. Stent induced false lumen thrombosis activated inflammatory markers like metalloproteinases and proinflammatory cytokines [48], which contribute in the progression of aneurysm by destruction of the extracellular matrix in the aortic wall and neoangiogenesis. Risk factors for the late development of aneurysm include (i) patent

*DOI: http://dx.doi.org/10.5772/intechopen.93015*

4.False lumen more than 22 mm

**Figure 11.**

*subclavian artery.*

**13. Frozen elephant trunk (FET)**

**14. Total aortic repair**

Indications for arch replacement include:


*Current and Future Management Strategies of Type A Aortic Dissection DOI: http://dx.doi.org/10.5772/intechopen.93015*

**Figure 11.**

*Advances in Complex Valvular Disease*

mortality was 11% [41].

*Proximal anastomoses of aortic root.*

**Figure 10.**

**11. Ascending aorta**

**12. Hemi-arch or full arch**

be performed (**Figure 11a**, **b**).

Indications for arch replacement include:

3.Secondary intimal tear in arch >10 mm

2.Primary intimal tear in distal arch or descending thoracic aorta

1.Pre-existing aneurysm of the arch

is due to unhinging of one of the aortic valve commissural posts. The dissected sinus segments are preserved and supported with resuspension of the native valve commissural posts or prosthetic ascending aorta replacement. The advantages are that it preserves the native sinus tissue, coronary ostia are not reimplanted, shorter ischemic time, avoiding life-long anticoagulation [40]. The most commonly used methods to fortify the aortic wall include Teflon felt and biologic glue. University of Pennsylvania in their series of 489 patients showed freedom from reoperation with this technique of 96, 92 and 89% at 1, 10 and 15 years respectively. The operative

The entry site of the dissection tear is usually found the ascending aorta, which is at very high risk of rupture. After excising the dissected portion of ascending aorta, supracommissural ascending aorta replacement can be performed. Open distal anastomoses can be done under hypothermic circulatory arrest after releasing the cross clamp. This facilitates inspection of the aortic arch and if required, arch repair can be undertaken. Also, it is technically much easier to construct a very distal ascending aortic anastomoses. Around 5.6% patients underwent ascending aorta replacement in GERAADA survey [42]. But this procedure also allows for subsequent aneurysmal dilation of the remaining portion of the aorta [43].

When the aortic arch is examined during hypothermic circulatory arrest to look for intimal or re-entry tears, a decision is made whether an aortic arch replacement has to be done. The pre-operative CT aortogram helps in localising the dissection and also on deciding the placement of the aortic cross clamp. If the tear is in the ascending aorta or start of the aortic curvature, then hemi-arch replacement is required. If the dissection is extends more distally, a total aortic arch repair should

**72**

*Total arch replacement. (a, b) Debranching of aortic arch vessels – innominate , carotid artery and left subclavian artery.*

4.False lumen more than 22 mm

5.Descending thoracic aorta diameter more than 35 mm

A study of 188 patients by Kim et al. [44] showed that 5 year survival was lower in patients with total arch replacement compared to patients who had hemi-arch repair (65.8% vs. 83.2%, p = 0.013). Neurological complications were higher in total arch repair group compared to hemi-arch (56.9% vs. 24.8%, p < 0.001).There was a direct correlation between patent false lumen in aortic arch or descending aorta and re-intervention. The German registry for TAAD showed no significant difference in peri-operative outcomes between both groups [45]. This group suggested a more aggressive approach to reduce the rate of interventions.
