3.1 Demographics and Preoperative characteristics
Eighty-two of the 1174 aTAAD patients chose medical management that was chosen by 30.8% of patients in 80 years group due to rupture of the dissection (Figure 1a/b). The patients aged 40-60 years constituted the largest proportion of patients (71.2%) and the youngest 20s (2.9%) and oldest 80s (1.6%) groups accounted for minimum percentage of patients. There was higher proportion of female patients as age increases.
Further analysis showed that the 20s group patients had the highest proportion of connective tissue diseases (Marfan’s syndrome) (28.1%). History of hypertension was present in 63 % patients ages between 40-70 years old and hypotension on admission was highest in 80s group (16.7%, P=0.038). (Table 1). The average BMI was 25.6 with the highest 33.1 in 30s group and lowest 19.5 in 80s group. There is significantly increased history of stroke(9.6% vs 1.9%, OR=5.5, 95% CI 2.6-11.5), coronary artery disease (CAD) (5.9% vs 2.0%, OR=3.1, 95% CI 1.3-7.2) in patients over 70 years old.
Table 1
Baseline demographics and characteristics
|
Total
|
20s
|
30s
|
40s
|
50s
|
60s
|
70s
|
80s
|
P value
|
Number
|
1092
|
32
|
146
|
281
|
286
|
211
|
118
|
18
|
|
Age
|
52 (62-44)
|
27 (28-25)
|
35.5(38-32)
|
45 (47-43)
|
54 (56-52)
|
64 (66-62)
|
74 (76-71)
|
82.5(84.25-80)
|
<0.001
|
Male
|
816 (74.7%)
|
30 (93.8%)
|
127 (87.0%)
|
244 (86.8%)
|
211 (73.8%)
|
130 (61.6%)
|
64 (54.2%)
|
10 (55.6%)
|
<0.001
|
BMI (kg/m2)
|
25.6±4.6
|
25.8±5.4
|
27.4±5.7
|
26.4±4.7
|
25.4±4.1
|
24.7±4.0
|
24.1±3.9
|
23.4±3.9
|
<0.001
|
Hypertension
|
807 (73.9%)
|
12 (37.5%)
|
95 (65.1%)
|
215 (76.5%)
|
219 (76.6%)
|
162 (76.8%)
|
92 (78.0%)
|
12 (66.7%)
|
<0.001
|
Marfan
|
26 (2.4%)
|
9 (28.1%)
|
4 (2.7%)
|
10 (3.6%)
|
2 (0.7%)
|
1 (0.5%)
|
0 (0%)
|
0 (0%)
|
<0.001
|
Diabetes
|
40 (3.7%)
|
0 (0%)
|
3 (2.1%)
|
8 (2.8%)
|
9 (3.1%)
|
11 (5.2%)
|
7 (5.9%)
|
2 (11.1%)
|
0.181
|
Smoke
|
250 (22.9%)
|
10 (31.3%)
|
34 (23.3%)
|
77 (27.4%)
|
71 (24.8%)
|
40 (19.0%)
|
14 (11.9%)
|
4 (22.2%)
|
0.019
|
Alcohol
|
167 (15.3%)
|
3 (9.4%)
|
28 (19.2%)
|
44 (15.7%)
|
54 (18.9%)
|
25 (11.8%)
|
11 (9.3%)
|
2 (11.1%)
|
0.098
|
End stage kidney disease
|
23 (2.1%)
|
0 (0.0%)
|
4 (2.7%)
|
5 (1.8%)
|
11(3.8%)
|
0 (0.0%)
|
3 (2.5%)
|
0 (0.0%)
|
0.072
|
Stroke history
|
31 (2.8%)
|
0 (0%)
|
1 (0.7%)
|
5 (1.8%)
|
7 (2.4%)
|
5 (2.4%)
|
10 (8.5%)
|
3 (16.7%)
|
0.001
|
CAD history
|
27 (2.5%)
|
0 (0%)
|
2 (1.4%)
|
3 (1.1%)
|
5 (1.7%)
|
9 (4.3%)
|
6 (5.1%)
|
2 (11.1%)
|
0.020
|
COPD history
|
11 (1.0%)
|
0 (0%)
|
1 (0.7%)
|
2 (0.7%)
|
3 (0.3%)
|
3 (1.4%)
|
2 (3.4%)
|
0 (0%)
|
0.919
|
AF history
|
10 (0.9%)
|
0 (0%)
|
1 (0.7%)
|
1 (0.4%)
|
2 (0.7%)
|
3 (1.4%)
|
2 (1.7%)
|
1 (5.6%)
|
0.273
|
Pain
|
1007 (92.3%)
|
28 (87.5%)
|
134 (91.8%)
|
262 (93.2%)
|
264 (92.3%)
|
194 (91.9%)
|
109 (92.4%)
|
17 (94.4%)
|
0.936
|
Chest
|
942 (86.3%)
|
28 (87.5%)
|
125 (85.6%)
|
244 (86.8%)
|
251 (87.8%)
|
179 (84.8%)
|
102 (86.4%)
|
15 (83.3%)
|
0.965
|
Back
|
433 (39.7%)
|
9 (28.1%)
|
59 (40.4%)
|
110 (39.1%)
|
122 (42.7%)
|
78 (37.0%)
|
50 (42.4%)
|
5 (27.8%)
|
0.565
|
Abdominal
|
59 (5.4%)
|
0 (0%)
|
10 (6.8%)
|
19 (6.8%)
|
12 (4.2%)
|
10 (4.7%)
|
5 (4.2%)
|
3 (16.7%)
|
0.197
|
Leg
|
32 (2.9%)
|
2 (6.3%)
|
5 (3.4%)
|
9 (3.2%)
|
8 (2.8%)
|
6 (2.8%)
|
2 (1.7%)
|
0 (0%)
|
0.848
|
Malperfusion
|
|
|
|
|
|
|
|
|
|
Cerebral
|
108 (9.9%)
|
0 (0%)
|
9 (6.2%)
|
26 (9.3%)
|
32 (11.2%)
|
21 (10%)
|
19 (16.1%)
|
1 (5.6%)
|
0.062
|
Limb
|
165 (15.1%)
|
7 (21.9%)
|
20 (13.7%)
|
49 (17.4%)
|
46 (16.1%)
|
30 (14.2%)
|
12 (10.2%)
|
1 (5.6%)
|
0.397
|
Bowel
|
47 (4.3%)
|
0 (0%)
|
4 (2.7%)
|
13 (4.6%)
|
13 (4.5%)
|
10 (4.7%)
|
7 (5.9%)
|
0 (0%)
|
0.666
|
Myocardial
|
52 (4.8%)
|
2 (6.3%)
|
11 (7.5%)
|
10 (3.6%)
|
14 (4.9%)
|
10 (4.7%)
|
5 (4.2%)
|
0 (0%)
|
0.646
|
Hypotension
|
64 (5.9%)
|
1 (3.1%)
|
4 (2.7%)
|
11 (3.9%)
|
20 (7.0%)
|
19 (9.0%)
|
6 (5.1%)
|
3 (16.7%)
|
0.040
|
Pericardial tamponade
|
131 (12.0%)
|
4 (12.5%)
|
5 (3.4%)
|
26 (9.3%)
|
39 (13.6%)
|
34 (16.1%)
|
22 (18.6%)
|
1 (5.6%)
|
0.001
|
Coronary artery involvement
|
215 (19.7%)
|
11 (34.4%)
|
28 (19.2%)
|
53 (18.9%)
|
62 (21.7%)
|
39 (18.5%)
|
21 (17.8%)
|
1 (5.6%)
|
0.278
|
Abbreviations: BMI (body mass index), CAD (coronary artery disease),COPD (chronic obstructive pulmonary disease) |
Pain was the main presenting symptom, while chest pain presented as similar among groups. Preoperative malperfusion were present in 34% of patients with no significant difference among age groups.
3.2 Operative characteristics
The duration of surgery, CPB, X-clamp and HCA decreased with advanced age starting from age group of 50 years old. Cannulating both femoral and axillary artery were preferred arterial cannulation approach compared to single femoral or axillary artery. Bentall procedure accounted for a large part of root methods in young age group (43.8% in 20s) and total arch replacement with FET had a higher rate in age group of 50s(45.8%), 60s(41.7%) than the 70s(26.3%) and 80s (16.7%)(P < 0.001)(Table 2).
Table 2
|
Total
|
20s
|
30s
|
40s
|
50s
|
60s
|
70s
|
80s
|
P value
|
Number
|
1092
|
32
|
146
|
281
|
286
|
211
|
118
|
18
|
|
Hour from onset to admission
|
10 (18-6)
|
10 (20-6)
|
10 (18-7)
|
10 (18-7)
|
9 (16-6)
|
10 (20-6)
|
10 (18-6)
|
9 (12-5)
|
0.374
|
Hours from admission to surgery
|
6 (12-3)
|
9 (12-3)
|
6 (13-3)
|
6 (14-3)
|
5 (12-3)
|
5 (12-2)
|
5 (10-3)
|
6 (12-3)
|
0.049
|
OP duration
|
8.0±2.1
|
8.2±2.1
|
8.2±2.1
|
8.3±2.2
|
7.8±2.3
|
7.7±1.9
|
7.7±1.9
|
7.1±1.6
|
<0.001
|
Cannulation
|
|
|
|
|
|
|
|
|
|
Ascending
|
20 (1.8%)
|
2 (6.3%)
|
3 (2.1%)
|
5 (1.8%)
|
3 (1.0%)
|
5 (2.4%)
|
2 (1.7%)
|
0 (0%)
|
0.521
|
Femoral
|
231 (21.2%)
|
7 (21.9%)
|
18 (12.3%)
|
36 (12.8%)
|
68 (23.8%)
|
61 (28.9%)
|
33 (28.0%)
|
8 (44.4%)
|
0.000
|
Axillary
|
233 (21.3%)
|
3 (9.4%)
|
25 (17.1%)
|
64 (22.8%)
|
56 (19.6%)
|
50 (23.7%)
|
30 (25.4%)
|
5 (27.8%)
|
0.281
|
Femoral+Axillary
|
608 (55.7%)
|
20 (62.5%)
|
100 (68.5%)
|
176 (62.6%)
|
159 (55.6%)
|
95 (45.0%)
|
53 (44.9%)
|
5 (27.8%)
|
0.000
|
HCA
|
30.3±11.1
|
29.2±15.6
|
32.4±12.6
|
30.7±10.8
|
29.7±10.8
|
30.6±11.1
|
28.7±8.5
|
24.8±8.7
|
0.021
|
CPB
|
240.0±76.1
|
238.8±64.4
|
253.6±74.2
|
245.9±81.4
|
237.7±76.7
|
234.7±75.9
|
228.3±66.9
|
219.3±61.1
|
0.012
|
X-clamp
|
166.8±61.1
|
168.5±47.4
|
179.8±59.3
|
169.8±72.3
|
164.1±57.6
|
163.1±57.8
|
157.8±49.1
|
159.7±59.8
|
0.049
|
Cerebral perfusion
|
|
|
|
|
|
|
|
|
<0.001
|
No perfusion
|
140 (12.8%)
|
7 (21.9%)
|
10 (6.8%)
|
23 (8.2%)
|
43 (15.0%)
|
39 (18.5%)
|
14 (11.9%)
|
4 (22.2%)
|
|
ACP
|
886 (81.1%)
|
25 (78.1%)
|
130 (89.0%)
|
250 (89.0%)
|
226 (79.0%)
|
153 (72.5%)
|
91 (77.1%)
|
11 (61.1%)
|
|
RCP
|
66 (6.0%)
|
0 (0%)
|
6 (4.1%)
|
8 (2.8%)
|
17 (5.9%)
|
19 (9.0%)
|
13 (11.0%)
|
3 (16.7%)
|
|
Root procedure
|
|
|
|
|
|
|
|
|
<0.001
|
No
|
17 (1.6%)
|
2 (6.3%)
|
2 (1.4%)
|
5 (1.8%)
|
3 (1.0%)
|
3 (1.4%)
|
2 (1.7%)
|
0 (0%)
|
|
Root reconstruction
|
828
(75.8%)
|
13 (40.6%)
|
99 (67.8%)
|
213 (75.8%)
|
214 (74.8%)
|
174 (82.5%)
|
101 (85.6%)
|
14 (77.8%)
|
|
Bentall
|
228 (20.9%)
|
14 (43.8%)
|
38 (26.0%)
|
60 (21.4%)
|
68 (23.8%)
|
30 (14.2%)
|
14 (11.9%)
|
4(22.2%)
|
|
VSRR
|
19 (1.7%)
|
3 (9.4%)
|
7 (4.8%)
|
3 (1.1%)
|
1 (0.3%)
|
4 (1.9%)
|
1 (0.8%)
|
0 (0%)
|
|
Arch procedure
|
|
|
|
|
|
|
|
|
<0.001
|
Sub-arch
|
211 (19.9%)
|
7 (21.9%)
|
18 (12.3%)
|
40 (14.2%)
|
49 (17.1%)
|
47 (22.3%)
|
45 (38.1%)
|
7 (38.9%)
|
|
Total arch + FET
|
515 (47.1%)
|
19 (59.4%)
|
88 (60.3%)
|
156 (55.5%)
|
131 (45.8%)
|
88 (41.7%)
|
31 (26.3%)
|
3 (16.7%)
|
|
Arch stent
|
361 (33.0%)
|
6 (18.8%)
|
40 (27.4%)
|
85 (30.2%)
|
106 (37.1%)
|
74 (35.1%)
|
41 (34.7%)
|
8 (44.4%)
|
|
Abbreviation: OP (operation), HCA (hypothermic circulatory arrest), CPB (cardiopulmonary bypass), ACP (antegrade cerebral perfusion), RCP (retrograde cerebral perfusion), VSRR (valve sparing root reconstruction), FET (frozen elephant trunk technique ) |
3.3 Immediate postoperative outcomes
One hundred and fifty-four patients (14.1%) died within 30 days after surgery, 93 (60.4%) from circulatory failure, 21 (13.6%) neurological complications, 15 (9.7%) aortic rupture, 13 (8.4%) respiratory failure or other reasons, 12 (7.8%) gastrointestinal bleeding or ischemia, (Table 3). Group 80s had significantly higher mortality than group 70s (33.3% vs 18.6%, p=0.016) (Figure 2a). A decreasing trend of mortality rate in 70s and 80s group was shown with year (Figure 2b). Age was related to postoperative complications. The stroke rates (died and not died) were 8.5%, 5.1% and 5.6% in 60s, 70s and 80s group respectively. Among patients succumbed in the 80 year group, there were significant high rate of GI bleeding and ischemia (16.7% and 11.1%, respectively) compared with other groups of 50s, 60s and 70s (1.4%, 0%, 0.8%, respectively ). The 70s group had higher duration of ICU stay when compared with other groups (20s group: p=0.048, 30s group: p=0.047, 50s group: p=0.011); however, the duration of hospital stay showed no significant difference in all age groups. There was no significant difference in mechanical ventilation, reintubation, tracheotomy, neurological complications, renal complications and re-exploration. The 20s group showed lowest postoperative neurological and gastrointestinal complications as they presented at admission. (Table 3).
Table 3
|
Total
|
20s
|
30s
|
40s
|
50s
|
60s
|
70s
|
80s
|
P value
|
Number
|
1092
|
32
|
146
|
281
|
286
|
211
|
118
|
18
|
|
30 day-mortality
|
154 (14.1%)
|
5 (15.6%)
|
11 (7.5%)
|
33 (11.7%)
|
41 (14.3%)
|
36 (17.1%)
|
22 (18.6%)
|
6 (33.3%)
|
0.016
|
Mechanical ventilation
|
56.2±79.1
|
71.6±130.2
|
61.2±90.4
|
55.2±69.6
|
57.5±93.8
|
52.9±63.3
|
49.3±51.0
|
67.6±80.4
|
0.808
|
Reintubation
|
70 (6.4%)
|
4 (12.5%)
|
6 (4.1%)
|
14 (5.0%)
|
23 (8.0%)
|
12 (5.7%)
|
11 (9.3%)
|
0 (0%)
|
0.199
|
Tracheotomy
|
44 (4.0%)
|
2 (6.3%)
|
4 (2.7%)
|
11 (3.9%)
|
10 (3.5%)
|
7 (3.3%)
|
10 (8.5%)
|
0 (0%)
|
0.216
|
ICH
|
9 (0.8%)
|
0 (0%)
|
1 (0.7%)
|
1 (0.4%)
|
5 (1.7%)
|
1 (0.5%)
|
1 (0.8%)
|
0 (0%)
|
0.609
|
Stroke
|
59 (5.4%)
|
0 (0%)
|
3 (2.1%)
|
14 (5.0%)
|
17 (5.9%)
|
18 (8.5%)
|
6 (5.1%)
|
1 (5.6%)
|
0.155
|
Paraplegia
|
23 (2.1%)
|
0 (0%)
|
4 (2.7%)
|
9 (3.2%)
|
7 (2.4%)
|
2 (0.9%)
|
1 (0.8%)
|
0 (0%)
|
0.489
|
GI bleeding
|
13 (1.2%)
|
0 (0%)
|
1 (0.7%)
|
4 (1.4%)
|
4 (1.4%)
|
0 (0%)
|
1 (0.8%)
|
3 (16.7%)
|
0.000
|
Limb ischemia
|
13 (1.2%)
|
0 (0%)
|
1 (0.7%)
|
5 (1.8%)
|
2 (0.7%)
|
5 (2.4%)
|
0 (0%)
|
0 (0%)
|
0.396
|
Bowel ischemia
|
16 (1.5%)
|
0 (0%)
|
3 (2.1%)
|
3 (1.1%)
|
3 (1.0%)
|
2 (0.9%)
|
3 (2.5%)
|
2 (11.1%)
|
0.025
|
Surgical site infection
|
37 (3.4%)
|
2 (6.3%)
|
3 (2.1%)
|
10 (3.6%)
|
9 (3.1%)
|
11 (5.2%)
|
2 (1.7%)
|
0 (0%)
|
0.484
|
Acute renal failure
|
339 (31.0%)
|
10 (31.3%)
|
50 (34.2%)
|
89 (31.7%)
|
97 (33.9%)
|
56 (26.5%)
|
31 (26.3%)
|
6 (33.3%)
|
0.525
|
CRRT
|
127 (11.6%)
|
2 (6.3%)
|
14 (9.6%)
|
35 (12.5%)
|
28 (9.8%)
|
27 (12.8%)
|
16 (13.6%)
|
5 (27.8%)
|
0.246
|
Reexploration
|
64 (5.8%)
|
0 (0%)
|
6 (4.1%)
|
14 (5.0%)
|
26 (9.1%)
|
11 (5.2%)
|
6 (5.1%)
|
0 (0%)
|
0.119
|
ICU stay (days)
|
5 (8-3)
|
4 (6-3)
|
5 (7-3)
|
6 (10-3)
|
5 (8-3)
|
5 (9.5-3)
|
6 (10-4)
|
5 (12-3)
|
0.046
|
Hospital stay (days)
|
20.8±13.1
|
21.9±11.4
|
20.5±10.0
|
21.7±13.2
|
19.5±11.5
|
21.8±14.5
|
20.5±17.2
|
14.4±10.8
|
0.236
|
Abbreviation: ICH (intracranial hemorrhage), GI (gastrointestinal), CRRT (continuous renal replacement therapy), ICU (intense care unit) |
3.4 Follow-up
927 (84.9%) patients completed followed up and the median follow-up was 17 months (1-102months). The 17-month survival rate was 82%. Thirty- eight discharged patients died during follow-up, 1(3.1%) in 20s group, 4(12.5%) in 30s group, 8(25%) in 40s group, 7(21.9%) in 50s group, 9(28.1%) in 60s group, 8(25%) in 70s group, and 1(3.1%) in 80s group. Figure 3a shows the mortality associated with age, the general tendency is that mortality increases with increasing age, 15.6% in 20s group, 7.5% in 30s group, 11.7% in 40s group, 14.3% in 50s group, 17.1% in 60s group, 18.6% in 70s group, and 33.3% in 80s group; however, the mortality of patients over 70 years old decreased over these years while the ratio of these patients remains relatively stable. Among the patients who died, 10 (26.3%) from aortic rupture, 5(13.2%) from neurological complications, and 2(5.3%) patients died for stent leakage. 137 patients had readmissions, of whom 34 (24.8%) patients had thoracoabdominal aortic dissection/aneurysm which is the leading cause of readmission. Figure 3b/3c shows the ratio of patients readmission for recurrence of aortic dissection, the tendency of readmission for abdominal aortic dissection decreased with age.