Current Management and Outcome of Chronic Type B Aortic Dissection

Results With Open and Endovascular Repair Since the Advent of Thoracic Endografting

Nicholas D. Andersen; Jeffrey E. Keenan; Asvin M. Ganapathi; Jeffrey G. Gaca; Richard L. McCann; G. Chad Hughes

Ann Cardiothorac Surg. 2014;3(3):264-274.

Abstract and Introduction

Abstract

Background: Thoracic endovascular aortic repair (TEVAR) has become the preferred treatment for chronic type B aortic dissection (CTBAD) at our institution. However, it remains incapable of treating all patients with CTBAD. The present study aims to review our contemporary results with open and endovascular CTBAD repairs since the advent of thoracic endografting.

Methods: The records of all patients undergoing index repair of CTBAD (chronic DeBakey type IIIA, IIIB and repaired type I) at our institution between June 2005 and December 2013, were retrospectively reviewed.

Results: A total of 107 patients underwent CTBAD repair, of whom 70% (n=75) underwent endovascular-based procedures [44 TEVAR, 27 hybrid arch and four hybrid thoracoabdominal aortic aneurysm (TAAA) repair] and 30% (n=32) underwent open procedures (nine open descending and 23 open TAAA). Connective tissue disease (CTD), prior aortic surgery and DeBakey dissection type were strongly associated with the choice of operation. The rates of stroke, paraplegia and operative mortality following endovascular-based repairs were 0%, 0% and 4% (n=3), respectively. Adverse neurologic events were higher following open repair, and rates of stroke, paraplegia, and operative mortality were 16% (n=5), 9% (n=3), and 6% (n=2), respectively. However, 1- and 5-year survival rates were similar for endovascular-based repairs (86% and 65%, respectively), and open repairs (88% and 79%, respectively). Over a median follow-up interval of 34 months, the rate of descending aortic reintervention was 24% (n=18) following endovascular-based repairs and 0% following open repairs (P=0.001). Forty-four percent (n=8) of descending aortic reinterventions were required to treat stent graft complications (five endoleak, two stent graft collapse and one stent graft-induced new entry tear) and the remainder were required to treat metachronous pathology (n=2) or progressive aneurysmal disease related to persistent distal fenestrations (n=8).

Conclusions: Endovascular repair of CTBAD was associated with excellent procedural and survival outcomes, but at the expense of further reinterventions. Open repair remains relevant for patients who are not candidates for endovascular repair and was associated with higher procedural morbidity but similar overall survival and fewer reinterventions.

Introduction

Of patients with uncomplicated dissection of the descending aorta, 20–40% will ultimately require surgical intervention, usually as a result of aneurysmal degeneration of the false lumen (FL).^[1,2] Despite initial skepticism,^[3] our aortic program was an early adopter of thoracic endovascular aortic repair (TEVAR) for chronic type B aortic dissection (CTBAD) in patients with suitable anatomy, in recognition of the reduced procedural morbidity and mortality with TEVAR compared with open surgery^[4] and excellent mid-term outcomes for CTBAD repair.^[1,2] However, TEVAR remains incapable of treating all CTBAD cases, and a significant proportion of patients require tailored hybrid or open repair due to unsuitable anatomy, prior surgery or connective tissue disease (CTD). The aim of the present study is to present our complete program results with open and endovascular CTBAD repair since the advent of thoracic endografting, with specific focus on procedural morbidity and mortality, survival and requirements for reintervention on the descending aorta.

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Abstract and Introduction
Methods
Results
Discussion
Conclusions
References

Table 1. Baseline characteristics
Variable	Overall (N=107)	TEVAR (n=44)	Hybrid arch (n=27)	Hybrid TAAA (n=4)	Open descending (n=9)	Open TAAA (n=23)	P value
Age [year]	56 [47,65]	59 [50,65]	57 [54,67]	66 [56,67]	63 [45,67]	47 [34,56]	0.06
Male	77 (72%)	28 (64%)	21 (78%)	1 (25%)	8 (89%)	19 (83%)	0.08
White race	53 (50%)	21 (48%)	16 (59%)	2 (50%)	4 (44%)	10 (44%)	0.81
Body mass index [kg/m²]	27 [23,31]	30 [26,33]	25 [23,28]	27 [22,31]	28 [24,31]	24 [21,28]	0.01
Hypertension	100 (94%)	43 (98%)	24 (89%)	4 (100%)	9 (100%)	20 (87%)	0.31
Hyperlipidemia	55 (51%)	21 (48%)	14 (52%)	3 (75%)	6 (67%)	11 (48%)	0.76
Active or recent tobacco use	64 (60%)	26 (59%)	16 (59%)	2 (50%)	3 (33%)	17 (74%)	0.31
Diabetes	7 (7%)	5 (11%)	1 (4%)	0	0	1 (4%)	0.69
Coronary artery disease	18 (17%)	5 (11%)	5 (19%)	0	2 (22%)	6 (26%)	0.53
History of prior stroke	11 (10%)	0	5 (19%)	0	1 (11%)	5 (22%)	0.01
COPD	18 (17%)	7 (16%)	4 (15%)	1 (25%)	0	6 (26%)	0.44
Baseline creatinine >1.5 mg/dL	22 (21%)	7 (16%)	11 (41%)	0 (0%)	1 (11%)	3 (13%)	0.08
Peripheral vascular disease	11 (10%)	6 (14%)	3 (11%)	0	0	2 (9%)	0.88
Connective tissue disease	10 (9%)	0	1 (4%)	0	0	9 (39%)	<0.001
Prior aortic surgery	60 (56%)	12 (27%)	24 (89%)	3 (75%)	6 (67%)	15 (65%)	<0.001

Data represented as median (interquartile range) or number (percent). COPD, chronic obstructive pulmonary disease; TAAA, thoracoabdominal aortic aneurysm; TEVAR, thoracic endovascular aortic repair.

Table 2. Anatomic and procedural characteristics
Variable	Overall (N=107)	TEVAR (n=44)	Hybrid arch (n=27)	Hybrid TAAA (n=4)	Open descending (n=9)	Open TAAA (n=23)	P value
Index dissection type							<0.001
DeBakey type I	47 (44%)	8 (18%)	21 (78%)	2 (50%)	5 (56%)	11 (48%)
DeBakey type IIIa	5 (5%)	2 (5%)	2 (7%)	0	1 (11%)	0
DeBakey type IIIb	55 (51%)	34 (77%)	4 (15%)	2 (50%)	3 (33%)	12 (52%)
Time in months from dissection	31 [7,83]	17 [4,72]	40 [14,80]	56 [50,72]	43 [22,87]	31 [9,85]	0.48
Maximum aortic diameter [cm]	6 [6,7]	6 [5,6]	6 [6,7]	7 [7,8]	7 [6,8]	6 [6,7]	0.02
Procedure status							0.35
Elective	86 (80%)	32 (73%)	25 (93%)	3 (75%)	8 (89%)	18 (78%)
Urgent	18 (17%)	11 (25%)	1 (4%)	1 (25%)	1 (11%)	4 (17%)
Emergent	3 (3%)	1 (2%)	1 (4%)	0	0	1 (4%)
Number of endografts implanted	2 [1,3]	2 [1,2]	2 [2,3]	4 [4,5]	–	–	0.001
Length of aortic coverage [cm]	25 [20,32]	20 [16,29]	31 [23,39]	59 [57,63]	–	–	<0.001
Proximal landing zone							<0.001
Stented elephant trunk	8 (11%)	0	6 (22%)	2 (50%)	–	–
Zone 0	17 (23%)	0	17 (63%)	0	–	–
Zone 1	5 (7%)	0	4 (15%)	1 (25%)	–	–
Zone 2	34 (45%)	33 (75%)	0	1 (25%)	–	–
Zone 3	4 (5%)	4 (9%)	0	0	–	–
Zone 4	7 (9%)	7 (16%)	0	0	–	–
Distal landing zone							<0.001
Above celiac axis	27 (37%)	18 (42%)	9 (33%)	0	–	–
To celiac axis	43 (58%)	25 (58%)	18 (67%)	0	–	–
Below celiac axis	4 (5%)	0	0	4 (100%)	–	–
Extent of TAAA							0.44
Type I	9 (33%)	–	–	0	–	9 (39%)
Type II	11 (41%)	–	–	3 (75%)	–	8 (35%)
Type III	6 (22%)	–	–	1 (25%)	–	5 (22%)
Type IV	1 (4%)	–	–	0	–	1 (4%)

Data represented as median (interquartile range) or number (percent). TAAA, thoracoabdominal aortic aneurysm; TEVAR, thoracic endovascular aortic repair.

Table 3. 30-day in-hospital adverse events
Variable	Overall (N=107)	TEVAR (n=44)	Hybrid arch (n=27)	Hybrid TAAA (n=4)	Open descending (n=9)	Open TAAA (n=23)	P value
Stroke (neurologic deficit lasting >72 hours)	5 (5%)	0	0	0	1 (11%)	4 (17%)	0.01
Permanent paraplegia/paraparesis	3 (3%)	0	0	0	0	3 (13%)	0.06
Acute renal failure (Cr >2.0 mg/dL and >2× baseline)	6 (6%)	1 (2%)	2 (7%)	0	0	3 (13%)	0.40
New onset dialysis	1 (1%)	0	1 (4%)	0	0	0	0.59
Prolonged ventilation (>24 hours)	7 (7%)	1 (2%)	1 (4%)	0	0	5 (22%)	0.06
Myocardial infarction	1 (1%)	1 (2%)	0	0	0	0	0.99
Retrograde type A aortic dissection	3 (3%)	2 (5%)	1 (4%)	0	0	0	0.81
Death	5 (5%)	0	3 (11%)	0	1 (11%)	1 (4%)	0.11
Postoperative length of stay [days]	5 [3,8]	3 [2,5]	5 [3,6]	6 [6,8]	6 [5,6]	8 [7,12]	0.01

Data represented as median (interquartile range) or number (percent). Cr, creatinine; TAAA, thoracoabdominal aortic aneurysm; TEVAR, thoracic endovascular aortic repair.

Table 4. Univariate risk factors for major morbidity (stroke, paraplegia/paraparesis, dialysis) or 1-year mortality for patients undergoing open repair
Variable	No morbidity/mortality (n=24)	Yes morbidity/mortality (n=8)	P value
Age [year]	47 [34,60]	62 [50,66]	0.05
Age >50 years	9 (38%)	6 (75%)	0.07
Male	20 (83%)	7 (88%)	0.78
White race	10 (42%)	4 (50%)	0.68
Body mass index [kg/m²]	25 [22,29]	25 [21,29]	0.86
Hypertension	22 (92%)	7 (88%)	0.73
Hyperlipidemia	11 (46%)	6 (75%)	0.15
Active or recent tobacco use	13 (54%)	7 (88%)	0.09
Diabetes	1 (4%)	0	0.56
Coronary artery disease	6 (25%)	2 (25%)	1
History of prior stroke	4 (17%)	2 (25%)	0.60
COPD	3 (13%)	3 (38%)	0.12
Baseline creatinine >1.5 mg/dL	3 (13%)	1 (13%)	1
Peripheral vascular disease	1 (4%)	1 (13%)	0.40
Connective tissue disease	8 (33%)	1 (13%)	0.26
Prior aortic surgery	16 (67%)	5 (63%)	0.83
Index dissection type			0.54
DeBakey type I	13 (54%)	3 (38%)
DeBakey type IIIa	1 (4%)	0
DeBakey type IIIb	10 (42%)	5 (63%)
Time in months from dissection	30 [10,64]	85 [16,142]	0.26
Maximum aortic diameter (cm)	6.2 (5.6,7.2)	6.8 (6.2,8.7)	0.15
Non-elective operation	5 (21%)	1 (13%)	0.60
Procedure performed			0.26
Open descending	8 (33%)	1 (13%)
Open TAAA	16 (67%)	7 (88%)
Extent of TAAA			0.78
Type I	6 (38%)	3 (43%)
Type II	6 (38%)	2 (29%)
Type III	3 (19%)	2 (29%)
Type IV	1 (6%)	0
Cardiopulmonary bypass time [min]	195 [179,227]	214 [189,247]	0.32
Cerebral circulatory arrest time [min]	17 [9,22]	17 [4,19]	0.46
Systemic circulatory arrest time [min]	51 [40,73]	70 [26,79]	0.45
Femoral arterial cannulation	7 (29%)	4 (50%)	0.28
Era (years)			0.04
2005–2009	8 (33%)	6 (75%)
2010–2013	16 (67%)	2 (25%)

Data represented as median (interquartile range) or number (percent). COPD, chronic obstructive pulmonary disease; TAAA, thoracoabdominal aortic aneurysm.

Table 5. Reinterventions during follow-up
Variable	Overall (N=107)	TEVAR (n=44)	Hybrid arch (n=27)	Hybrid TAAA (n=4)	Open descending (n=9)	Open TAAA (n=23)	P value
Duration of follow-up [months]	34 [13,68]	44 [16,73]	27 [9,52]	23 [17,31]	28 [9,32]	34 [16,77]	0.04
Descending aortic reinterventions	18 (17%)	11 (25%)	4 (15%)	3 (75%)	0	0	0.001
Endovascular reintervention only	11 (10%)	6 (14%)	2 (7%)	3 (75%)	–	–
Conversion to hybrid arch repair	1 (1%)	1 (2%)	0	0	–	–
Conversion to hybrid TAAA repair	4 (4%)	2 (5%)	2 (7%)	0	–	–
Conversion to open TAAA repair	2 (2%)	2 (5%)	0	0	–	–
Indication for descending reintervention
Type IA endoleak	2 (2%)	1 (2%)	1 (4%)	0	–	–
Type IB endoleak	2 (2%)	1 (2%)	0	1 (25%)	–	–
Type III endoleak	1 (1%)	0	0	1 (25%)	–	–
Stent graft collapse	2 (2%)	1 (2%)	0	1 (25%)	–	–
Stent graft-induced new entry tear	1 (1%)	0	1 (4%)	0	–	–
Metachronous saccular aneurysm	1 (1%)	1 (2%)	0	0	–	–
Aortoesophageal fistula	1 (1%)	1 (2%)	0	0	–	–
Persistent FL pressurization via distal fenestrations	8 (7%)	6 (14%)	2 (7%)	0	–	–
Reintervention for arch pathology	7 (7%)	3 (7%)	0	0	0	4 (17%)	0.12
Endovascular	1 (1%)	1 (2%)	–	–	–	0
Hybrid	3 (3%)	0	–	–	–	3 (13%)
Open	3 (3%)	2 (5%)	–	–	–	1 (4%)
Total patients requiring any aortic reintervention	25 (23%)	14 (32%)	4 (15%)	3 (75%)	0	4 (17%)	0.02

Data represented as median (interquartile range) or number (percent). FL, false lumen; TAAA, thoracoabdominal aortic aneurysm; TEVAR, thoracic endovascular aortic repair.