Endovascular repair of type B aortic dissection with the restrictive bare stent technique: morphologic changes, technique details, and outcomes

Figures & data

Figure 1 A 63-year-old man who presented with 3 months of chest and back pain was diagnosed with chronic TBAD with aneurysm degeneration (using patient 4 as an example). Total stent graft diameter and length were 36 mm and 200 mm, respectively. Two RBSs were implanted, and the diameter of the proximal RBS was 26 mm.

Notes: (A–C) Preoperative CTA and intraoperative angiography showing severe tortuosity of the descending aorta (TI =1.62) and collapsed TL (TR =0.89, OR =9.9). Intraoperative angiography verifying the TL collapse. (D, E) Two RBSs (black arrow) were first placed to reduce the angle between the distal end of the stent and the aorta and to locate the stent fixation site in a straight portion of the descending aorta. The stent graft was then deployed to seal the proximal entry tear, leaving its distal end partially within the RBS. (F, G) Postoperative angiography showing satisfactory repair of the dissected aorta using the RBS procedure. Meanwhile, the tortuosity of the descending aorta was corrected. TL was obviously expanded, and no endoleak was observed. (H) CTA at postoperative year 1 showing satisfactory occlusion of the aortic dissection with re-expansion of the TL and RBS collapse.
Abbreviations: TR, taper ratio; OR, oversizing ratio of the stent graft; TI, tortuosity index; TBAD, type B aortic dissection; RBS, restrictive bare stent; TL, true lumen; CTA, computed tomography angiography.

Figure 2 Measurement of the local and global anatomy of the descending aorta (TR, OR and TI).

Notes: (A) Sagittal computed tomography view before TEVAR showing the size of the presumed proximal landing zone (X_PRO) and the presumed distal landing zone (X_A). (B) Maximal diameter and area of X_A. (C) TI =b/a, defined as the length of the midline (b) within the aorta divided by the linear distance (a) between the left subclavian artery and the celiac trunk.
Abbreviations: TR, taper ratio; OR, oversizing ratio of the stent graft; TI, tortuosity index; TEVAR, thoracic endovascular aortic repair; Max, maximal; diam, diameter.

Table 1 Patient characteristics

Variable	Preoperation CTA	Postoperation CTA	P-value
TR	0.79±0.08	0.50±0.15	<0.001
OR	4.74±2.68	1.93±1.03	<0.001
TI	1.44±0.17	1.32±0.16	<0.05

Note: Continuous data are presented as mean ± SD.

Abbreviations: CTA, computed tomography angiography; OR, oversizing ratio of the stent graft; TI, tortuosity index; TR, taper ratio.

Table 2 Demographic characteristics and stent techniques

Patient	Gender	Age (years)	Emergency vs planned	Treatment phase	Aneurysm degeneration	Indications of RBS	TR	OR	TI	Branch vessel compromise	Coverage of LSA (%)	Size of SG (mm)	Size and number of RBSs (mm)	Additional procedure
1	M	70	Planned	Subacute	No	TL compressed and tortuosity	0.79	2.52	1.78	NA	0	ANCURA (34×30×160)	28×80, 28×80; 28×80	NA
2	M	51	Planned	Chronic	Yes	TL collapsed and tortuosity	0.82	3.49	1.73	NA	100	Grink TNS-X2 (34×28×180)	24×80; 22×80; 20×80	NA
3	M	50	Planned	Chronic	Yes	TL compressed and tortuosity	0.77	2.73	1.68	NA	100	Cook Zenith TX2 (34×30×200)	26×80; 28×100; 24×80	NA
4	M	63	Planned	Chronic	Yes	TL collapsed and tortuosity	0.89	9.94	1.62	NA	50	Captivia (36×36×200)	22×80; 26×80	NA
5	F	75	Planned	Acute	No	TL compressed and tortuosity	0.69	2.19	1.57	NA	75	Captivia (28×28×150)	26×80	NA
6	F	62	Planned	Subacute	No	TL collapsed and tortuosity	0.79	4.75	1.56	NA	100	ANCURA (38×34×160)	26×80	NA
7	M	64	Emergency	Chronic	Yes	TL collapsed and tortuosity	0.88	4.65	1.54	NA	100	ANCURA (32×24×200)	24×80; 24×80	NA
8	M	63	Planned	Chronic	No	TL compressed and tortuosity	0.66	3.06	1.51	NA	100	Captivia (36×36×200)	24×80; 22×80	NA
9	M	53	Planned	Chronic	Yes	TL compressed and tortuosity	0.74	2.01	1.45	NA	50	ANCURA (38×30×200)	26×80; 28×80	NA
10	F	53	Planned	Subacute	No	TL compressed and tortuosity	0.67	2.45	1.43	NA	100	Captivia (32×32×150)	24×80	NA
11	M	53	Emergency	Acute	No	TL collapsed	0.86	7.94	1.43	SMA	100	Captivia (32×32×200)	28×80	Distal bare stent extension
12	F	53	Planned	Acute	No	TL compressed and tortuosity	0.73	2.73	1.41	NA	100	Cook Zenith TX2 (28×28×140)	24×80	NA
13	M	57	Planned	Acute	No	TL compressed and tortuosity	0.57	1.38	1.39	NA	50	Captivia (30×30×150)	24×80	NA
14	M	55	Planned	Chronic	Yes	TL collapsed	0.9	10.98	1.35	NA	100	Captivia (30×30×150)	18×80; 20×60	NA
15	M	33	Emergency	Acute	No	TL collapsed	0.8	3.6	1.34	Right iliac artery	100	Captivia (32×32×150)	24×80; 22×80; 20×80	NA
16	M	39	Planned	Subacute	No	TL compressed	0.69	2.76	1.32	NA	100	Captivia (32×32×150)	24×80	NA
17	F	63	Planned	Subacute	No	TL compressed	0.75	2.81	1.28	NA	0	Captivia (32×32×150)	26×80	NA
18	M	66	Planned	Chronic	No	TL compressed	0.76	2.52	1.26	NA	0	Cook Zenith TX2 (34×30×197)	28×60	NA
19	M	50	Emergency	Acute	No	TL collapsed	0.79	4.04	1.25	Right iliac artery	100	Captivia (34×34×150)	28×80	Femoral–femoral bypass
20	M	34	Emergency	Acute	No	TL collapsed	0.81	5.7	1.24	SMA	100	Captivia (32×32×200)	24×80	PTA
21	M	61	Planned	Chronic	No	TL collapsed	0.79	4.01	1.2	NA	100	Captivia (30×30×200)	28×80	NA
22	M	40	Planned	Acute	No	TL compressed	0.62	2.24	1.19	NA	75	Captivia (32×32×150)	26×80	NA

Abbreviations: F, female; LSA, left subclavian artery; M, male; NA, not applicable; OR, oversizing ratio of the SG; PTA, percutaneous angioplasty; RBS, restrictive bare stent; SG, stent graft; SMA, superior mesenteric artery; TI, tortuosity index; TL, true lumen; TR, taper ratio.

Table 3 Procedural details of the RBS technique

Variable	Result (n=22)
SG median length (mm)	181.2±23.9
Stent graft with taper	7 (31.8)
RBS
Median diameter (mm)	24.7±2.7
Median length (mm)	126.3±66
Number of RBSs	1.6±0.8
Coverage of LSA
Total coverage	14 (63.6)
Partial coverage	5 (22.7)
No coverage	3 (13.6)
Adjunctive procedures
Chimney stent	0
Femoral–femoral bypass	1 (4.5)
Mesenteric artery bare stent	1 (4.5)
Mesenteric artery PTA	1 (4.5)
Renal artery bare stent	0

Note: Continuous data are presented as mean ± SD and categorical data are presented as number (%).

Abbreviations: LSA, left subclavian artery; PTA, percutaneous angioplasty; RBS, restrictive bare stent; SG, stent graft.

Table 4 Outcomes and follow-up data

Variable	Result (n=22)
Days from onset to TEVAR
Acute (≤14 days)	8 (36.4)
Subacute (>14 days, <3 months)	5 (22.7)
Chronic (>3 months)	9 (40.9)
TBAD with aneurysm degeneration	6 (31.8)
Complications
Endoleak	0
Paraplegia	0
Stroke	0
Distal SINE	0
Acute renal failure	0
Bow and limb ischemia	0
RBS collapsed	3 (13.6)
Reintervention for all causes	0 (0)
30-day mortality	0 (0)
Overall aorta-related death	1 (4.5)

Note: Categorical data are presented as number (%).

Abbreviations: RBS, restrictive bare stent; SINE, stent graft-induced new entry; TBAD, type B aortic dissection; TEVAR, thoracic endovascular aortic repair.