1. Influence of Hospital Volume on Outcomes of Thoracic Endovascular Repair in Vascular Quality Initiative Database:
5-year National Study.
Presenting Author: Satinderjit (Vinny) Locham, MD
Post-Doctoral Research Fellow
University of California San Diego
Senior Author: Mahmoud Malas, MD MHS RPVI FACS
Professor In Residence
Chief Division of Vascular and Endovascular Surgery
UCSD, Health System

2. Disclosures:
None

3. Background:
Gore TAG was the first commercially available thoracic endografts introduced in 2005.
Since then, multiple devices have been approved.
Original Gore TAG
Conformable Gore TAG
Bolton RelayPlus
Valiant
Zenith Alpha

4. Background:
Relationship between hospital volume and outcomes in AAA repair have been well described.
However, very few studies are available on TEVAR.

5. 1,838 patients

6. From 2005-2007, patients treated at HVH (>17 per year)
From , patients treated at HVH (>17 per year)
Since 2011, 53% have undergone TEVAR by low volume surgeons

7. Medicare claims ( ).
12,573 open and 2,732 TEVAR

9. Aim of the study:
To use a large national vascular database and look at the influence of hospital volume and outcomes in patients undergoing TEVAR.

10. Methods: Inclusion: Exclusion:
All patients undergoing TEVAR ( ).
Exclusion:
Distal extent (zone >6).
PAU/Hematoma/thrombus

11. Methods: Hospital volumes (Low vs. High)
Total mean number of cases per year at each center.
Grouped them into two quintiles.
Stratified by symptomatic status.
Asymptomatic vs. Symptomatic/Rupture.
Statistical analysis:
Univariate: Student t-test, median, chi-square.
Multivariable logistic regression analysis.

12. Results: N=2,639 Centers - 133 Asymp. N=1,363 (52%) LVH (54%)
HVH (46%)
Symp.
N=1,276 (48%)
LVH (47%)
HVH (53%)

13. Results: Trends

14. Results: Demographics
Asymptomatic
Symptomatic/Rupture
Low
High
P-value
741 (54.4%)
622 (45.6%)
598 (46.9%)
678 (53.1%)
Mean number of cases, SD
4.80 (1.95)
19.22 (13.33)
5.12 (2.03)
20.01 (12.56)
Demographics
Age, median (IQR)
72 (63,78)
70 (61,77)
0.10
63 (47,75)
64 (49,75)
0.73
Male
455 (61.4)
367 (59.0)
0.37
359 (60.0)
418 (61.7)
0.55
Race
0.06
0.81
White
565 (76.3)
476 (76.5)
364 (60.9)
410 (60.5)
Black
108 (14.6)
108 (17.4)
160 (26.8)
176 (26.0)
Others
69 (9.2)
38 (6.1)
74 (12.4)
92 (13.6)

15. Results: Comorbidities
Asymptomatic
Symptomatic/Rupture
Low
High
P-value
Hx CAD
144 (19.5)
104 (16.7)
0.19
88 (14.8)
90 (13.3)
0.45
Hx CHF
102 (13.8)
66 (10.6)
0.08
60 (10.1)
60 (8.9)
0.46
Hx COPD
232 (31.4)
185 (29.7)
0.51
118 (19.8)
141 (20.9)
0.65
Hx DM
133 (18.0)
95 (15.3)
0.18
75 (12.6)
95 (14.1)
Hx Dialysis
16 (2.2)
20 (3.2)
0.23
20 (3.4)
15 (2.2)
0.22
HTN
621 (83.9)
522 (83.9)
0.99
430 (72.2)
498 (73.7)
0.54
Smoker
544 ( 73.5)
464 (75.0)
375 (63.3)
416 (61.7)
0.55
Hx PCI/CABG
150 (20.3)
128 (20.6)
0.89
79 (13.3)
97 (14.4)
0.58
Hx CEA/CAS
28 (3.8)
16 (2.6)
0.21
12 (2.0)
14 (2.1)
0.95
Aneurysm repair
236 (31.9)
188 (30.2)
98 (16.5)
111 (16.4)
0.98
PVI/Bypass
81 (11.0)
88 (14.2)
0.07
33 (5.6)
67 (9.9)
0.004
Major amputation
6 (0.8)
3 (0.5)
2 (0.3)

16. Results: Operative characteristics
Asymptomatic
Symptomatic/Rupture
Low
High
P-value
Urgency
0.36
0.16
Elective
648 (87.5)
554 (89.1)
223 (37.3)
279 (41.2)
Urgent/Emergent
93 (12.6)
68 (10.9)
375 (62.7)
399 (58.9)
Contrast, mean (S.D.)
(66.30)
(68.33)
0.94
97.75 (65.14)
91.66 (58.85)
0.09
Crystalloid in liters
1.69 (1.09)
1.74 (1.07)
0.53
1.68 (1.17)
1.72 (1.23)
0.6
EBL, mean (S.D.)
(822.63)
(333.78)
0.02
(475.95)
(319.55)
Flurotime, mean (S.D.)
18.34 (18.44)
17.19 (16.94)
0.26
14.38 (13.48)
13.53 (12.98)
0.27
Total procedure time
140.41
(98.91)
135.45
(81.13)
0.32
142.75
(115.00)
125.52
(85.94)
0.002
Intraoperative transfusion
120 (16.3)
100 (16.1)
0.93
147 (24.7)
187 (27.6)
0.24
IVUS/TEE use
262 (35.6)
278 (44.9)
<0.001
319 (54.1)
418 (61.7)
0.006
Conversion to open repair
4 (0.5)
4 (0.6)
0.8
4 (0.7)
5 (0.6)
0.86

17. Results: Operative characteristics
Asymptomatic
Symptomatic/Rupture
Low
High
P-value
Spinal drain placement
<0.001
0.004
None
403 (54.5)
273 (43.9)
189 (31.7)
264 (56.7)
Preop/postop
336 (45.5)
349 (56.1)
211 (35.4)
293 (43.3)
Custom modified grafts
17 (2.3)
5 (0.8)
0.03
17 (2.9)
5 (0.7)
Branch Staged Procedure
86 (31.4)
120 (40.4)
44 (18.3)
92 (26.8)
0.02
Proximal Zone
0.005
Zone 0,1,2
157 (21.9)
200 (32.2)
151 (25.3)
228 (33.6)
Zone 3
302 (40.8)
254 (40.8)
318 (53.2)
322 (47.5)
Zone 4,5
282 (38.1)
168 (27.0)
129 (21.6)
128 (18.9)

18. Results: Outcomes

19. Results: Logistic regression.
HVH (Ref) vs. LVH
Asymptomatic
Symptomatic/Rupture
OR (95% CI)
P-Value
30-day mortality
1.15 ( )
0.72
0.94 ( )
0.84
Renal
0.88 ( )
2.21 ( )
0.03
Neuro
0.86 ( )
0.60
0.93 ( )
0.77
Cardiac
1.26 ( )
0.29
1.01 ( )
0.96
Pulmonary
1.12 ( )
0.68
1.02 ( )
0.95
Adjusted for age, gender, coronary disease, urgency (elective vs emergent/urgent), indication (trauma vs. dissection vs. aneurysm), blood loss, and proximal zone of the disease (zone 0-2 vs. zone 3 vs. zone4).

20. Conclusion: Increased in number of TEVARs performed at LVH.
HVHs operate on more complex patients (higher thoracic zones [0-2]).
30-day mortality independent of hospital volume.
Long-term studies on durability and re-interventions are needed.

21. THANK YOU!.