**2.1.3 Other expandable device models**

276 Front Lines of Thoracic Surgery

The type III device incorporates an external sleeve that substitutes the external ligature, thus allowing standardization of the pressure applied to the vascular stump wall. The wire-frame

The outer surface of the inner sleeve was wrapped by a latex cuff (top squares) in order to overcome the problem of the porosity of the dacron graft and the requirement for the connection of the tube graft to the proximal end of the inner sleeve as in its final clinical use. A) The air-tightness of the connection was verified at endovascular pressures of up to 150 mmHg in a regular cylindrical anastomosis of ascending aorta (white bars). (B) The same was verified when the anastomosis is irregularly oriented, such as when involves the arch concavity. (C) As easily predictable, a standard suture (4–0 prolene) of an approximately 3 cm incision of the aortic wall cannot be proved airtight even at minor endovascular pressure. (Nazari, 2010). Video at http://www.fondazionecarrel.org/tsb2/tsb2.html

of the device is quite soft and compliant, and can be easily compressed and widely deformed while maintaining perfect reciprocal alignment of the internal and external sleeves (top left squares). Lower squares: First of all both sleeves are set at predicted final aperture. Acting only on the activating guide of the inner sleeve results in outer sleeve backwards rotation and eversion, bringing the retracted inner sleeve in full visibility, so that can be easily inserted into the vascular stump. Then inner ring is expanded as much as the vascular wall can be distended by acting contrariwise on the same guide. At this point, the outer sleeve is only slightly retracted towards the aortic wall using its own guide. (Nazari,

2010) Video at http://www.fondazionecarrel.org/tsb2/tsb2.html

Fig. 14. Device type III.

Fig. 15. Device type III seal test.

We also realized a variety of modified versions of the device to better fit with the anatomical configurations occurring in particular clinical circumstances.

#### **2.1.3.1 Type I – SOLD (Single Outer Layer for small Diameters)**

In small vessel diameters obviously device dimensions can interfere more significantly with physiological lumen amplitude in their range of use. More in particular the unpredictable way of folding of the inner fabric layer when the device is incompletely opened may significantly reduce the lumen available for the blood flow. Accordingly for diameters ≤ 12 and ≥6 mm we decided to use devices wrapped by fabric only at external layer (fig. 16). Two sizes were prepared respectively for diameter from 6 to 9 (SS) and from 10 to 12 mm (S). This may fit for renal artery, celiac axis and supraortic trunks. The device is previously prepared at the end of collateral branch of the main tube graft tailored at the expected appropriated length or directly on the main tube graft. The particular fabric disposition implies a mandatory blood flow direction, which however allows the use as main tube graft lateral branches for the major aortic branches.

Fig. 16. Device type I – SOLD.

For small diameters vessels (≥6mm ≤12mm) device type I was prepared with single outer fabric graft in order to prevent the possible significant interference with vascular lumen of unpredictable way of folding of the inner layer when the device cannot be fully expanded. These devices allow one way flow direction only.

Video at http://www.fondazionecarrel.org/tsb2/tsb2.html
