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Enlargement of aortic arch vessels after surgical repair of type A aortic dissection
Enlargement of aortic arch vessels after surgical repair of type A aortic dissection Takashi Yamauchi, MD, PhD,a Suguru Kubota, MD, PhD,a Toshihiro Ohata, MD, PhD,a Kosei Hasegawa, MD,a and Hideki Ueda, MD, PhD,b Sapporo and Chiba City, Japan
ABSTRACT Background: Information on the growth rate of the diameter of the residual dissected supra-aortic trunk after surgical repair of type A aortic dissection is limited. Methods: We retrospectively reviewed 95 consecutive postsurgical patients with type A aortic dissection (acute, 91; chronic, 4) between 2005 and 2016 who were followed up with computed tomography. The diameter of the residual dissected supra-aortic trunk was measured by axial images and multiplanar reformatting, and the growth rate was calculated. Results: The mean age was 67.2 6 12.8 years (range, 34-89 years). Forty-one brachiocephalic arteries (43%), 14 left common carotid arteries (15%), and 7 left subclavian arteries (10%) exhibited residual dissection. The diameter of the residual dissected branch with a patent false lumen (FL) gradually increased over time, whereas that with a thrombosed FL decreased and reached a plateau. The growth rate of brachiocephalic, left common carotid, and left subclavian arteries with a patent FL was 1.3 6 1.2, 0.8 6 0.3, and 0.6 6 0.4 mm/y, respectively. One patient required surgical intervention for dilation of the brachiocephalic artery 8 years postoperatively. Multivariate analysis showed that male sex was an independent risk factor for a patent FL in the brachiocephalic artery (P ¼ .0431; odds ratio, 2.04). Conclusions: A residual dissected supra-aortic trunk with a thrombosed FL seems to be a benign condition. However, long-term follow-up is necessary for patients with a patent FL of residual dissected supra-aortic trunk, which might occasionally require surgical intervention. (J Vasc Surg 2016;-:1-7.)
The implications of a residual dissected supra-aortic trunk after surgical treatment of acute type A dissection have mainly been discussed from the viewpoint of late neurologic events.1-3 Rupture of dissected supra-aortic trunk has also been reported.4-6 The incidence and outcome of the residual dissected branch after surgical repair of aortic type A dissection are unclear. The aim of this study was to investigate the incidence of a residual dissected supra-aortic trunk and to determine the growth rate of the diameter of this vessel.
METHODS From October 2005 to July 2016, 98 consecutive patients underwent surgical repair of type A aortic dissection (acute, 94; chronic, 4). The study cohort is summarized in Fig 1. We obtained informed consent not only for the operation but also for clinical investigation before
From the Department of Cardiovascular Surgery, KKR Sapporo Medical Center, Sapporoa; and the Department of Cardiovascular Surgery, Chiba Graduate School of Medicine, Chiba City.b Author conflict of interest: none. Correspondence: Takashi Yamauchi, MD, PhD, Department of Cardiovascular Surgery, KKR Sapporo Medical Center, 6-3-40 Ichijo Hiragishi, Toyohira, Sapporo, Hokkaido 062-0931, Japan (e-mail: [email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214 Copyright Ó 2016 by the Society for Vascular Surgery. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jvs.2016.09.056
surgery. This study was a retrospective study and was approved by our hospital’s Institutional Review Board. Informed consent was waived by the Institutional Review Board, given the retrospective nature of the study using records without patient identifiers. Imaging. The patients’ postoperative computed tomography (CT) scans were retrospectively reviewed. Postoperative CT angiography within 1 week postoperatively was performed in 95 patients to evaluate residual dissection of the supra-aortic trunk (brachiocephalic artery [BCA], left common carotid artery [LCCA], and left subclavian artery [LSCA]) of the aortic arch, which enabled confirmation of the presence of a residual dissected branch. In total, 251 scans of 34 patients were available for follow-up analysis. Of the 251 scans, 159 were CT scans with arterial contrast enhancement and 92 were CT scans without contrast enhancement. During the first year, CT was scheduled to be performed at 6 months and 1 year after the operation. After that, CT at the interval of 1 year was performed if the aortic condition was stable. In cases in which the residual dissected distal aorta showed the tendency to enlarge, CT at the interval of 6 months was performed. The unenhanced CT studies were follow-up studies obtained during the chronic phase and were used only to measure the branch diameter. All CT studies were performed using a 64-row multidetector CT system (Aquilion 64 or Aquilion 64 CXL; Toshiba Medical Systems, Otawara, Japan) with 1-mm collimation 1
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from the neck to the femoral artery. The diameter of the residual dissected supra-aortic trunk was measured from axial images and multiplanar reformatting, and the growth rate of each branch was calculated from this value.
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Statistical analysis. Continuous variables are reported as mean and standard deviation, and categorical data are reported as count and percentage. We compared the growth rate of the diameter using an unpaired t-test. We conducted multivariate stepwise logistic regression analysis to investigate the risk factors for a patent false lumen [FL] in the BCA. All calculations were performed using SPSS 18.0 (SPSS Inc, Hong Kong).
RESULTS The patients’ characteristics are summarized in Table I. A residual dissected BCA, LCCA, and LSCA was present in 41 of 95 (43%), 14 of 95 (15%), and 7 of 71 (10%) patients, respectively (Table II). Twenty-four patients whose LSCA was ligated were excluded to evaluate the condition of the LSCA. A patent FL of the BCA, LCCA, and LSCA was found in 21 of 41 (51%), 10 of 14 (71%), and 4 of 7 (57%) patients, respectively. To investigate the change in the diameter over time, 34 patients with at least one dissected branch and a >1-month follow-up were investigated (Table I). The changes in the diameter of the BCA are listed in Fig 2. We considered the change >1 mm as increasing diameter or shrinkage in this study. A residual dissected BCA with a patent FL exhibited an increasing diameter in 80% (12/15) of patients, no change in 13% (2/15), and shrinkage in 7% (1/15; Fig 2, a). One case of shrinkage occurred in a patient in whom the patent FL became spontaneously thrombosed 1 year postoperatively. In contrast, a residual dissected BCA with a thrombosed FL exhibited an increasing diameter in 0% (0/18) of patients, no change in 28% (5/18), and shrinkage in 72% (13/18). The diameter seemed to reach a plateau between 1 year and 3 years postoperatively (Fig 2, b). The changes in the diameter of the LCCA and LSCA are listed in Fig 3. A residual dissected LCCA and LSCA with a patent FL exhibited an increasing diameter in all cases (Fig 3, a). In contrast, a residual dissected LCCA with a thrombosed FL exhibited shrinkage in all cases during the follow-up period (Fig 3, b). To calculate the growth rate of the diameter of these dissected vessels, 22 patients with >1-year follow-up were also analyzed (Table I). The growth rates of the dissected BCA, LCCA, and LSCA are summarized in Table III. The initial diameter of each vessel was not significantly different between patent and thrombosed FLs. The growth rate of a BCA with a patent FL was significantly higher than that with a thrombosed FL (1.28 6 1.18 vs 1.85 6 2.89 mm/y, respectively; P ¼ .0037). The growth rate of an LCCA with a patent FL was also significantly higher than that with a thrombosed FL (0.81 6 0.34
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Significance: This manuscript provides important information on the fate of the supra-aortic trunk after open surgical repair of type A dissection. Type of Research: Retrospective single-center observational study of 95 patients after open repair for type A dissection Take Home Message: False lumen (FL) thrombosis of the supra-aortic trunk was associated with a good prognosis, but patent FL needed follow-up, and one patient required repair. Recommendation: Monitoring of the supra-aortic trunk with computed tomography angiography after open repair of type A dissection is warranted, and those with patent FL should be observed. Strength of Recommendation: 2. Weak Level of Evidence: C. Low or very low
vs 0.46 6 0.13 mm/y, respectively; P ¼ .0005). The growth rate of the LSCA exhibited the same tendency. The growth rate of the LSCA with a patent FL was 0.60 6 0.39, whereas that with a thrombosed FL was 0.70 6 0.83. We also analyzed the independent factors affecting patency of the FL in the BCA, which seemed to be relatively frequent and to present a clinical problem (Table IV). Univariate analysis showed that age (#60 years), sex (male), and a preoperative dissected BCA with a complete FL thrombosis were significant risk factors. Multivariate analysis showed that sex (male) was a significant factor (P ¼ .0431; odds ratio, 2.04; 95% confidence interval, 1.07-55.81). During the follow-up period, one patient without connective tissue disease, such as Marfan syndrome, required surgical intervention for a dilated BCA 8 years after emergent total arch replacement for acute type A aortic dissection. The diameter of the dissected BCA gradually increased from 27 mm (Fig 4, a) to 40 mm (Fig 4, b and c) after the onset of the dissection.
DISCUSSION A residual dissected supra-aortic trunk after surgical treatment of acute type A aortic dissection has mainly been discussed from the viewpoint of late neurologic events.1-3 These dissected vessels are associated with the potential risk of neurologic events. According to a report published in the 1990s, a dissected branch was considered to be a benign condition.1,2 Neri et al3 reported that residual dissection of the BCA was associated with a higher risk of cerebral ischemic events than previously expected. In contrast, few reports have addressed this issue from the viewpoint of aneurysmal formation or rupture, probably because aneurysmal formation of a residual
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Acute or chronic DAA (A) undergoing surgery 98 cases
Postoperative CT performed within 1 wk after operation 95 cases
42 cases: No of dissected BCA (41：43%)/ LCCA(14:15%)/LSCA(7:10%) ( to investigate the incidence of the residual dissection; Table 2)
Postoperative CT performed > 1 month after operation 80 cases
34 cases: No of dissected BCA (33:41%)/ LCCA(10:13%)/LSCA(6:10%) ( to investigate the change of the diameter; Figure 2,3)
Postoperative CT performed > 1y after operation 49 cases
22 cases: No of dissected BCA (21:43%)/ LCCA(9:21%)/LSCA(6:14%) ( to calculate the growth rate of the diameter; Table 3)
Fig 1. Study cohort. BCA, Brachiocephalic artery; CT, computed tomography; DAA, dissecting aortic aneurysm; LCCA, left common carotid artery; LSCA, left subclavian artery.
Table I. Patient characteristics
Age, years Gender Marfan syndrome Acute/chronic dissection Follow-up period, years
All cases (N ¼ 95)
>1-Month follow-up with dissected branch (n ¼ 34)
$1-Year follow-up with dissected branch (n ¼ 22)
67.2 6 12.8 (34-89)
63.8 6 13.0 (37-85)
63.8 6 15.2 (37-85)
Male: 41 Female: 54
Male: 16 Female: 18
Male: 10 Female: 12
4 cases
3 cases
3 cases
91/4
34/0
22/0
2.2 6 2.5 (1-106 months)
2.7 6 2.8 (1-106 months)
3.8 6 2.8 (12-106 months)
Graft replacement of ascending aorta
33
12
10
Total arch replacement
47
16
8
10/5
5/1
3/1
24
2
2
4 (mechanical: 3)
0
0
Partial arch replacement (BCA/BCA-LCCA reconstruction) Ligation of LSCA (left axillary artery bypass) Concomitant aortic valve replacement
BCA, Brachiocephalic artery; LCCA, left common carotid artery; LSCA, left subclavian artery.
Table II. Residual dissected supra-aortic trunk after surgical repair of acute type A dissection Artery BCA (n ¼ 95)
Residual dissection Yes
41 (43%)
No
54 (57%)
LCCA (n ¼ 95)
Yes
14 (15%)
No
81 (85%)
LSCA (n ¼ 71)
Yes
7 (10%)
No
63 (90%)
State of FL Patent: 21 Thrombosed: 20 Patent: 10 Thrombosed: 4 Patent: 4 Thrombosed: 3
BCA, Brachiocephalic artery; FL, false lumen; LCCA, left common carotid artery; LSCA, left subclavian artery.
dissected BCA, LCCA, and LSCA requiring surgical intervention seems extremely rare. Neri et al3 performed 16 operations in 12 of 42 patients with residual dissection of the BCA. The indications for surgery were symptoms of carotid hypoperfusion, symptomatic subclavian steal syndrome, and multiple transient ischemic attacks; no operation was performed for dilation of the BCA. Spontaneous rupture of the BCA in the acute phase has also been reported.5,6 Kieffer et al4 reported three cases of surgical repair of a chronic dissected innominate artery. The details of the dissected BCA, such as its diameter, were not addressed in their article. Therefore, the surgical indications for dilated dissected supra-aortic trunk remain unclear. Kieffer et al4 considered that patients
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a (mm)
b (mm)
Patent false lumen (n=15)
40
Thrombosed false lumen (n=18)
40
35
35
30
30
25
25
20*
20
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* Spontaneous thrombosed case
15
15
10
10 0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
year
9 year
Fig 2. Change in diameter of dissected brachiocephalic artery (BCA). a, Patent false lumen (FL). b, Thrombosed FL.
a
b
Patent false lumen (n=9)
(mm)
Thrombosed false lumen (n=7)
(mm)
18
18
16
16
14
14
12
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6 4
4 0
1
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8 year
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8 year
Fig 3. Change in diameter of dissected left common carotid artery (LCCA) and left subclavian artery (LSCA). a, Patent false lumen (FL). b, Thrombosed FL.
with asymptomatic isolated true aneurysms with low surgical risk should undergo surgery when the aneurysms are saccular or when their maximum transverse diameter is >3 cm. Takach and Lalka7 reported open surgical repair of an innominate artery aneurysm complicated with a thromboembolic event in the upper extremity and concluded that the true BCA aneurysm should be considered for early intervention on the basis of the potential for the development of complications.
This study revealed that a residual dissected supraaortic trunk with thrombosis seems to be a benign condition, as expected. The diameter began to decrease from the early postoperative period and reached a plateau at around 3 years in most cases. However, the course of the change in the diameter of dissected branches with a patent FL was different. In some cases, the diameter reached a plateau within several years. Spontaneous thrombosis of the FL was occasionally observed in follow-up.1 In other cases, the diameter
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Table III. Growth rate of dissected brachiocephalic artery (BCA), left common carotid artery (LCCA), and left subclavian artery (LSCA) at $1-year follow-up State of FL
Initial diameter, mm
P value
Growth rate, mm/y
BCA (n ¼ 21)
Patent: 11 Thrombosed: 10
18.7 6 4.3 17.2 6 3.4
.3836
1.3 6 1.2 1.9 6 2.9
.0037
LCCA (n ¼ 9)
Patent: 6 Thrombosed: 3
10.8 6 0.8 10.6 6 1.2
.798
0.8 6 0.3 0.5 6 0.1
.0005
LSCA (n ¼ 6)
Patent: 2 Thrombosed: 4
11.0 6 1.4 11.0 6 2.9
da
0.6 6 0.4 0.7 6 0.8
da
Artery
P value
FL, False lumen. a Statistical analysis was not performed due to small number of the patients.
Table IV. Predictors of postoperative dissected brachiocephalic artery (BCA) with patent false lumen (FL) Univariate Age <60 years
P ¼ .0244
Marfan syndrome
P ¼ .1100
Gender, male
P ¼ .0091
Preoperative dissected BCA with complete FL thrombosis
P ¼ .0064
Preoperative dissected BCA with patent FL
P ¼ .0559
Resection of primary tear
P ¼ .4705
Graft replacement of ascending aorta
P ¼ .2685
Graft replacement of ascending aorta and total arch
P ¼ .3733
Multivariate
P ¼ .0431 (2.04; 1.07-55.81)
continued to increase over time, and some of these cases should be considered for surgical intervention. The average growth rate was slow at around 1 mm/y. Therefore, long-term follow-up is necessary. After the surgical repair of type A dissection, aortic surveillance is usually necessary because the enlargement of residual dissected distal aorta or pseudoaneurysm is not rare. Therefore, we recommend that attention be paid not only to residual dissected native aorta but also to aortic arch vessels during the routine aortic surveillance. For the surveillance of dissected aortic arch branches with patent FL, CT at intervals of several years would be sufficient. In cases of thrombosed FL of those vessels, CT surveillance for dissected aortic arch branch might not be indicated. The factors affecting the growth rate of the dissected branch are one of the concerns. There seems to be little doubt that a patent FL is associated with growth according to the result of this study. This study revealed that male sex was significantly associated with a patent FL in the BCA. Neither resection of the primary entry nor extent of replacement of the aorta was significantly associated with a patent BCA. The impact of
anticoagulation therapy on the patent FL of the residual dissected supra-aortic trunk is also one of the concerns. In this study, three patients with mechanical aortic valve and two patients with atrial fibrillation underwent anticoagulation. Among five patients, dissected BCA was observed in only one patient. Therefore, we could not conclude the association between anticoagulation therapy and patent FL of residual dissected supra-aortic trunk. To the best of our knowledge, no previous reports have described the risk factors of enlargement of residual dissected aortic branches (eg, aortic arch branches, celiac, superior mesenteric, renal artery, internal iliac artery) after surgical repair of type A dissection. By contrast, various articles have addressed the risk factors of enlargement of distal aorta after surgery for type A dissection or dissected aorta in chronic type B dissection. After type A dissection, partial thrombosis, uncontrolled hypertension, nonresection of the entry site, distal extension of a dissection, and Marfan syndrome have been reported to be risk factors.8-12 As for type B dissection, partially thrombosed FL, male sex, and saccular FL have been reported to be risk factors, whereas increased age, increased number of entry tears, FL located on the outer curvature of the aorta, and circular configuration of the true lumen were associated with decreased aortic growth.13,14 In this study, younger age (<60 years), Marfan syndrome, and male sex tended to be risk factors of patent FL of the BCA in univariate analysis. In view of the previous reports cited before, factors such as younger age, male sex, and Marfan syndrome might be considered to be associated with increasing risk of patent FL of the BCA, resulting in gradual enlargement. This study has some limitations. The cohort size was relatively small. Not all CT studies were enhanced, which would be desirable to evaluate the condition of the FL, because of some patients’ renal dysfunction. Moreover, the follow-up period was relatively short (3.4 6 2.8 years; range, 1-106 months) in a study in which the target values (growth rate of the vessels) changed gradually. Further follow-up is needed to determine the operative indications for these dissected vessels after surgical repair of type A aortic dissection.
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Fig 4. Residual dissected brachiocephalic artery (BCA) aneurysm required surgical intervention (our case outside the study cohort) after surgical repair of type A dissection. The diameter of the dissected BCA gradually increased from 27 mm (a) to 40 mm 8 years after the onset of the dissection (b and c).
CONCLUSIONS After surgical repair of type A aortic dissection, a residual dissected supra-aortic trunk with a thrombosed FL seems to be a benign condition. Although the growth rate of aortic arch vessels is relatively slow and the incidence requiring surgical intervention for chronic dilated aortic arch vessels is considered low even in cases with patent FL, we recommend that attention be paid not only to residual dissected native aorta but also to dissected aortic arch vessels during routine aortic surveillance.
AUTHOR CONTRIBUTIONS Conception and design: TY Analysis and interpretation: TY, SK, KH Data collection: TY Writing the article: TY Critical revision of the article: TY, SK, KH, TO, HU Final approval of the article: TY, SK, KH, TO, HU Statistical analysis: TY Obtained funding: Not applicable Overall responsibility: TY
REFERENCES 1. Zielinski T, Wolkanin-Bartnik J, Janaszek-Sitkowska H, Biederman A, Rynkun D, Makowiecka-Ciesla M, et al. Persistent dissection of carotid artery in patients operated on for type A acute aortic dissectiondcarotid ultrasound follow-up. Int J Cardiol 1999;70:133-9. 2. Zurbrugg HR, Leupi F, Schupbach P, Althaus U. Duplex scanner study of carotid artery dissection following surgical treatment of aortic dissection type A. Stroke 1988;19:970-6.
3. Neri E, Sani G, Massetti M, Frati G, Buklas D, Tassi R, et al. Residual dissection of the brachiocephalic arteries: significance, management, and long-term outcome. J Thorac Cardiovasc Surg 2004;128:303-12. 4. Kieffer E, Chiche L, Koskas F, Bahnini A. Aneurysms of the innominate artery: surgical treatment of 27 patients. J Vasc Surg 2001;34:222-8. 5. Kaul P, George R, Paniagua R, Petsa A, Congiu S. Innominate truncal dissection and rupture into right pleural cavity following acute type A dissection of the aorta with right coronary ostial avulsion and inferior STEMI. Perfusion 2011;26: 435-40. 6. Tamura K, Kihara K, Chikazawa G, Sakaguchi T, Yoshitaka H. A case of dissection and rupture of the innominate artery in acute type A aortic dissection. Ann Vasc Surg 2016;9:117-9. 7. Takach TJ, Lalka SG. Innominate artery aneurysm: axial reconstruction via a cervical approach. J Vasc Surg 2007;46: 1267-9. 8. Song SW, Chang BC, Cho BK, Yi G, Youn YN, Lee S, et al. Effects of partial thrombosis on distal aorta after repair of acute DeBakey type I aortic dissection. J Thorac Cardiovasc Surg 2010;139:841-7.e1; discussion: 847. 9. Kirsch M, Soustelle C, Houel R, Hillion ML, Loisance D. Risk factor analysis for proximal and distal reoperations after surgery for acute type A aortic dissection. J Thorac Cardiovasc Surg 2002;123:318-25. 10. Zierer A, Voeller RK, Hill KE, Kouchoukos NT, Damiano RJ Jr, Moon MR. Aortic enlargement and late reoperation after repair of acute type A aortic dissection. Ann Thorac Surg 2007;84:479-86; discussion: 486-7. 11. Bachet JE, Termignon JL, Dreyfus G, Goudot B, Martinelli L, Piquois A, et al. Aortic dissection. Prevalence, cause, and results of late reoperations. J Thorac Cardiovasc Surg 1994;108:199-205; discussion: 205-6. 12. Kazui T, Washiyama N, Bashar AH, Terada H, Suzuki T, Ohkura K, et al. Surgical outcome of acute type A aortic
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dissection: analysis of risk factors. Ann Thorac Surg 2002;74: 75-81; discussion: 81-2. 13. Trimarchi S, Tolenaar JL, Jonker FH, Murray B, Tsai TT, Eagle KA, et al. Importance of false lumen thrombosis in type B aortic dissection prognosis. J Thorac Cardiovasc Surg 2013;145: S208-12.
14. Tolenaar JL, van Keulen JW, Jonker FH, van Herwaarden JA, Verhagen HJ, Moll FL, et al. Morphologic predictors of aortic dilatation in type B aortic dissection. J Vasc Surg 2013;58:1220-5.
Submitted Sep 1, 2016; accepted Sep 30, 2016.
ABSTRACT Background: Information on the growth rate of the diameter of the residual dissected supra-aortic trunk after surgical repair of type A aortic dissection is limited. Methods: We retrospectively reviewed 95 consecutive postsurgical patients with type A aortic dissection (acute, 91; chronic, 4) between 2005 and 2016 who were followed up with computed tomography. The diameter of the residual dissected supra-aortic trunk was measured by axial images and multiplanar reformatting, and the growth rate was calculated. Results: The mean age was 67.2 6 12.8 years (range, 34-89 years). Forty-one brachiocephalic arteries (43%), 14 left common carotid arteries (15%), and 7 left subclavian arteries (10%) exhibited residual dissection. The diameter of the residual dissected branch with a patent false lumen (FL) gradually increased over time, whereas that with a thrombosed FL decreased and reached a plateau. The growth rate of brachiocephalic, left common carotid, and left subclavian arteries with a patent FL was 1.3 6 1.2, 0.8 6 0.3, and 0.6 6 0.4 mm/y, respectively. One patient required surgical intervention for dilation of the brachiocephalic artery 8 years postoperatively. Multivariate analysis showed that male sex was an independent risk factor for a patent FL in the brachiocephalic artery (P ¼ .0431; odds ratio, 2.04). Conclusions: A residual dissected supra-aortic trunk with a thrombosed FL seems to be a benign condition. However, long-term follow-up is necessary for patients with a patent FL of residual dissected supra-aortic trunk, which might occasionally require surgical intervention. (J Vasc Surg 2016;-:1-7.)
The implications of a residual dissected supra-aortic trunk after surgical treatment of acute type A dissection have mainly been discussed from the viewpoint of late neurologic events.1-3 Rupture of dissected supra-aortic trunk has also been reported.4-6 The incidence and outcome of the residual dissected branch after surgical repair of aortic type A dissection are unclear. The aim of this study was to investigate the incidence of a residual dissected supra-aortic trunk and to determine the growth rate of the diameter of this vessel.
METHODS From October 2005 to July 2016, 98 consecutive patients underwent surgical repair of type A aortic dissection (acute, 94; chronic, 4). The study cohort is summarized in Fig 1. We obtained informed consent not only for the operation but also for clinical investigation before
From the Department of Cardiovascular Surgery, KKR Sapporo Medical Center, Sapporoa; and the Department of Cardiovascular Surgery, Chiba Graduate School of Medicine, Chiba City.b Author conflict of interest: none. Correspondence: Takashi Yamauchi, MD, PhD, Department of Cardiovascular Surgery, KKR Sapporo Medical Center, 6-3-40 Ichijo Hiragishi, Toyohira, Sapporo, Hokkaido 062-0931, Japan (e-mail: [email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214 Copyright Ó 2016 by the Society for Vascular Surgery. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jvs.2016.09.056
surgery. This study was a retrospective study and was approved by our hospital’s Institutional Review Board. Informed consent was waived by the Institutional Review Board, given the retrospective nature of the study using records without patient identifiers. Imaging. The patients’ postoperative computed tomography (CT) scans were retrospectively reviewed. Postoperative CT angiography within 1 week postoperatively was performed in 95 patients to evaluate residual dissection of the supra-aortic trunk (brachiocephalic artery [BCA], left common carotid artery [LCCA], and left subclavian artery [LSCA]) of the aortic arch, which enabled confirmation of the presence of a residual dissected branch. In total, 251 scans of 34 patients were available for follow-up analysis. Of the 251 scans, 159 were CT scans with arterial contrast enhancement and 92 were CT scans without contrast enhancement. During the first year, CT was scheduled to be performed at 6 months and 1 year after the operation. After that, CT at the interval of 1 year was performed if the aortic condition was stable. In cases in which the residual dissected distal aorta showed the tendency to enlarge, CT at the interval of 6 months was performed. The unenhanced CT studies were follow-up studies obtained during the chronic phase and were used only to measure the branch diameter. All CT studies were performed using a 64-row multidetector CT system (Aquilion 64 or Aquilion 64 CXL; Toshiba Medical Systems, Otawara, Japan) with 1-mm collimation 1
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from the neck to the femoral artery. The diameter of the residual dissected supra-aortic trunk was measured from axial images and multiplanar reformatting, and the growth rate of each branch was calculated from this value.
ARTICLE HIGHLIGHTS d
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Statistical analysis. Continuous variables are reported as mean and standard deviation, and categorical data are reported as count and percentage. We compared the growth rate of the diameter using an unpaired t-test. We conducted multivariate stepwise logistic regression analysis to investigate the risk factors for a patent false lumen [FL] in the BCA. All calculations were performed using SPSS 18.0 (SPSS Inc, Hong Kong).
RESULTS The patients’ characteristics are summarized in Table I. A residual dissected BCA, LCCA, and LSCA was present in 41 of 95 (43%), 14 of 95 (15%), and 7 of 71 (10%) patients, respectively (Table II). Twenty-four patients whose LSCA was ligated were excluded to evaluate the condition of the LSCA. A patent FL of the BCA, LCCA, and LSCA was found in 21 of 41 (51%), 10 of 14 (71%), and 4 of 7 (57%) patients, respectively. To investigate the change in the diameter over time, 34 patients with at least one dissected branch and a >1-month follow-up were investigated (Table I). The changes in the diameter of the BCA are listed in Fig 2. We considered the change >1 mm as increasing diameter or shrinkage in this study. A residual dissected BCA with a patent FL exhibited an increasing diameter in 80% (12/15) of patients, no change in 13% (2/15), and shrinkage in 7% (1/15; Fig 2, a). One case of shrinkage occurred in a patient in whom the patent FL became spontaneously thrombosed 1 year postoperatively. In contrast, a residual dissected BCA with a thrombosed FL exhibited an increasing diameter in 0% (0/18) of patients, no change in 28% (5/18), and shrinkage in 72% (13/18). The diameter seemed to reach a plateau between 1 year and 3 years postoperatively (Fig 2, b). The changes in the diameter of the LCCA and LSCA are listed in Fig 3. A residual dissected LCCA and LSCA with a patent FL exhibited an increasing diameter in all cases (Fig 3, a). In contrast, a residual dissected LCCA with a thrombosed FL exhibited shrinkage in all cases during the follow-up period (Fig 3, b). To calculate the growth rate of the diameter of these dissected vessels, 22 patients with >1-year follow-up were also analyzed (Table I). The growth rates of the dissected BCA, LCCA, and LSCA are summarized in Table III. The initial diameter of each vessel was not significantly different between patent and thrombosed FLs. The growth rate of a BCA with a patent FL was significantly higher than that with a thrombosed FL (1.28 6 1.18 vs 1.85 6 2.89 mm/y, respectively; P ¼ .0037). The growth rate of an LCCA with a patent FL was also significantly higher than that with a thrombosed FL (0.81 6 0.34
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d
Significance: This manuscript provides important information on the fate of the supra-aortic trunk after open surgical repair of type A dissection. Type of Research: Retrospective single-center observational study of 95 patients after open repair for type A dissection Take Home Message: False lumen (FL) thrombosis of the supra-aortic trunk was associated with a good prognosis, but patent FL needed follow-up, and one patient required repair. Recommendation: Monitoring of the supra-aortic trunk with computed tomography angiography after open repair of type A dissection is warranted, and those with patent FL should be observed. Strength of Recommendation: 2. Weak Level of Evidence: C. Low or very low
vs 0.46 6 0.13 mm/y, respectively; P ¼ .0005). The growth rate of the LSCA exhibited the same tendency. The growth rate of the LSCA with a patent FL was 0.60 6 0.39, whereas that with a thrombosed FL was 0.70 6 0.83. We also analyzed the independent factors affecting patency of the FL in the BCA, which seemed to be relatively frequent and to present a clinical problem (Table IV). Univariate analysis showed that age (#60 years), sex (male), and a preoperative dissected BCA with a complete FL thrombosis were significant risk factors. Multivariate analysis showed that sex (male) was a significant factor (P ¼ .0431; odds ratio, 2.04; 95% confidence interval, 1.07-55.81). During the follow-up period, one patient without connective tissue disease, such as Marfan syndrome, required surgical intervention for a dilated BCA 8 years after emergent total arch replacement for acute type A aortic dissection. The diameter of the dissected BCA gradually increased from 27 mm (Fig 4, a) to 40 mm (Fig 4, b and c) after the onset of the dissection.
DISCUSSION A residual dissected supra-aortic trunk after surgical treatment of acute type A aortic dissection has mainly been discussed from the viewpoint of late neurologic events.1-3 These dissected vessels are associated with the potential risk of neurologic events. According to a report published in the 1990s, a dissected branch was considered to be a benign condition.1,2 Neri et al3 reported that residual dissection of the BCA was associated with a higher risk of cerebral ischemic events than previously expected. In contrast, few reports have addressed this issue from the viewpoint of aneurysmal formation or rupture, probably because aneurysmal formation of a residual
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Acute or chronic DAA (A) undergoing surgery 98 cases
Postoperative CT performed within 1 wk after operation 95 cases
42 cases: No of dissected BCA (41：43%)/ LCCA(14:15%)/LSCA(7:10%) ( to investigate the incidence of the residual dissection; Table 2)
Postoperative CT performed > 1 month after operation 80 cases
34 cases: No of dissected BCA (33:41%)/ LCCA(10:13%)/LSCA(6:10%) ( to investigate the change of the diameter; Figure 2,3)
Postoperative CT performed > 1y after operation 49 cases
22 cases: No of dissected BCA (21:43%)/ LCCA(9:21%)/LSCA(6:14%) ( to calculate the growth rate of the diameter; Table 3)
Fig 1. Study cohort. BCA, Brachiocephalic artery; CT, computed tomography; DAA, dissecting aortic aneurysm; LCCA, left common carotid artery; LSCA, left subclavian artery.
Table I. Patient characteristics
Age, years Gender Marfan syndrome Acute/chronic dissection Follow-up period, years
All cases (N ¼ 95)
>1-Month follow-up with dissected branch (n ¼ 34)
$1-Year follow-up with dissected branch (n ¼ 22)
67.2 6 12.8 (34-89)
63.8 6 13.0 (37-85)
63.8 6 15.2 (37-85)
Male: 41 Female: 54
Male: 16 Female: 18
Male: 10 Female: 12
4 cases
3 cases
3 cases
91/4
34/0
22/0
2.2 6 2.5 (1-106 months)
2.7 6 2.8 (1-106 months)
3.8 6 2.8 (12-106 months)
Graft replacement of ascending aorta
33
12
10
Total arch replacement
47
16
8
10/5
5/1
3/1
24
2
2
4 (mechanical: 3)
0
0
Partial arch replacement (BCA/BCA-LCCA reconstruction) Ligation of LSCA (left axillary artery bypass) Concomitant aortic valve replacement
BCA, Brachiocephalic artery; LCCA, left common carotid artery; LSCA, left subclavian artery.
Table II. Residual dissected supra-aortic trunk after surgical repair of acute type A dissection Artery BCA (n ¼ 95)
Residual dissection Yes
41 (43%)
No
54 (57%)
LCCA (n ¼ 95)
Yes
14 (15%)
No
81 (85%)
LSCA (n ¼ 71)
Yes
7 (10%)
No
63 (90%)
State of FL Patent: 21 Thrombosed: 20 Patent: 10 Thrombosed: 4 Patent: 4 Thrombosed: 3
BCA, Brachiocephalic artery; FL, false lumen; LCCA, left common carotid artery; LSCA, left subclavian artery.
dissected BCA, LCCA, and LSCA requiring surgical intervention seems extremely rare. Neri et al3 performed 16 operations in 12 of 42 patients with residual dissection of the BCA. The indications for surgery were symptoms of carotid hypoperfusion, symptomatic subclavian steal syndrome, and multiple transient ischemic attacks; no operation was performed for dilation of the BCA. Spontaneous rupture of the BCA in the acute phase has also been reported.5,6 Kieffer et al4 reported three cases of surgical repair of a chronic dissected innominate artery. The details of the dissected BCA, such as its diameter, were not addressed in their article. Therefore, the surgical indications for dilated dissected supra-aortic trunk remain unclear. Kieffer et al4 considered that patients
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a (mm)
b (mm)
Patent false lumen (n=15)
40
Thrombosed false lumen (n=18)
40
35
35
30
30
25
25
20*
20
2016
* Spontaneous thrombosed case
15
15
10
10 0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
year
9 year
Fig 2. Change in diameter of dissected brachiocephalic artery (BCA). a, Patent false lumen (FL). b, Thrombosed FL.
a
b
Patent false lumen (n=9)
(mm)
Thrombosed false lumen (n=7)
(mm)
18
18
16
16
14
14
12
12
10
10
8
8
6
6 4
4 0
1
2
3
4
5
6
7
8 year
0
1
2
3
4
5
6
7
8 year
Fig 3. Change in diameter of dissected left common carotid artery (LCCA) and left subclavian artery (LSCA). a, Patent false lumen (FL). b, Thrombosed FL.
with asymptomatic isolated true aneurysms with low surgical risk should undergo surgery when the aneurysms are saccular or when their maximum transverse diameter is >3 cm. Takach and Lalka7 reported open surgical repair of an innominate artery aneurysm complicated with a thromboembolic event in the upper extremity and concluded that the true BCA aneurysm should be considered for early intervention on the basis of the potential for the development of complications.
This study revealed that a residual dissected supraaortic trunk with thrombosis seems to be a benign condition, as expected. The diameter began to decrease from the early postoperative period and reached a plateau at around 3 years in most cases. However, the course of the change in the diameter of dissected branches with a patent FL was different. In some cases, the diameter reached a plateau within several years. Spontaneous thrombosis of the FL was occasionally observed in follow-up.1 In other cases, the diameter
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Table III. Growth rate of dissected brachiocephalic artery (BCA), left common carotid artery (LCCA), and left subclavian artery (LSCA) at $1-year follow-up State of FL
Initial diameter, mm
P value
Growth rate, mm/y
BCA (n ¼ 21)
Patent: 11 Thrombosed: 10
18.7 6 4.3 17.2 6 3.4
.3836
1.3 6 1.2 1.9 6 2.9
.0037
LCCA (n ¼ 9)
Patent: 6 Thrombosed: 3
10.8 6 0.8 10.6 6 1.2
.798
0.8 6 0.3 0.5 6 0.1
.0005
LSCA (n ¼ 6)
Patent: 2 Thrombosed: 4
11.0 6 1.4 11.0 6 2.9
da
0.6 6 0.4 0.7 6 0.8
da
Artery
P value
FL, False lumen. a Statistical analysis was not performed due to small number of the patients.
Table IV. Predictors of postoperative dissected brachiocephalic artery (BCA) with patent false lumen (FL) Univariate Age <60 years
P ¼ .0244
Marfan syndrome
P ¼ .1100
Gender, male
P ¼ .0091
Preoperative dissected BCA with complete FL thrombosis
P ¼ .0064
Preoperative dissected BCA with patent FL
P ¼ .0559
Resection of primary tear
P ¼ .4705
Graft replacement of ascending aorta
P ¼ .2685
Graft replacement of ascending aorta and total arch
P ¼ .3733
Multivariate
P ¼ .0431 (2.04; 1.07-55.81)
continued to increase over time, and some of these cases should be considered for surgical intervention. The average growth rate was slow at around 1 mm/y. Therefore, long-term follow-up is necessary. After the surgical repair of type A dissection, aortic surveillance is usually necessary because the enlargement of residual dissected distal aorta or pseudoaneurysm is not rare. Therefore, we recommend that attention be paid not only to residual dissected native aorta but also to aortic arch vessels during the routine aortic surveillance. For the surveillance of dissected aortic arch branches with patent FL, CT at intervals of several years would be sufficient. In cases of thrombosed FL of those vessels, CT surveillance for dissected aortic arch branch might not be indicated. The factors affecting the growth rate of the dissected branch are one of the concerns. There seems to be little doubt that a patent FL is associated with growth according to the result of this study. This study revealed that male sex was significantly associated with a patent FL in the BCA. Neither resection of the primary entry nor extent of replacement of the aorta was significantly associated with a patent BCA. The impact of
anticoagulation therapy on the patent FL of the residual dissected supra-aortic trunk is also one of the concerns. In this study, three patients with mechanical aortic valve and two patients with atrial fibrillation underwent anticoagulation. Among five patients, dissected BCA was observed in only one patient. Therefore, we could not conclude the association between anticoagulation therapy and patent FL of residual dissected supra-aortic trunk. To the best of our knowledge, no previous reports have described the risk factors of enlargement of residual dissected aortic branches (eg, aortic arch branches, celiac, superior mesenteric, renal artery, internal iliac artery) after surgical repair of type A dissection. By contrast, various articles have addressed the risk factors of enlargement of distal aorta after surgery for type A dissection or dissected aorta in chronic type B dissection. After type A dissection, partial thrombosis, uncontrolled hypertension, nonresection of the entry site, distal extension of a dissection, and Marfan syndrome have been reported to be risk factors.8-12 As for type B dissection, partially thrombosed FL, male sex, and saccular FL have been reported to be risk factors, whereas increased age, increased number of entry tears, FL located on the outer curvature of the aorta, and circular configuration of the true lumen were associated with decreased aortic growth.13,14 In this study, younger age (<60 years), Marfan syndrome, and male sex tended to be risk factors of patent FL of the BCA in univariate analysis. In view of the previous reports cited before, factors such as younger age, male sex, and Marfan syndrome might be considered to be associated with increasing risk of patent FL of the BCA, resulting in gradual enlargement. This study has some limitations. The cohort size was relatively small. Not all CT studies were enhanced, which would be desirable to evaluate the condition of the FL, because of some patients’ renal dysfunction. Moreover, the follow-up period was relatively short (3.4 6 2.8 years; range, 1-106 months) in a study in which the target values (growth rate of the vessels) changed gradually. Further follow-up is needed to determine the operative indications for these dissected vessels after surgical repair of type A aortic dissection.
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Fig 4. Residual dissected brachiocephalic artery (BCA) aneurysm required surgical intervention (our case outside the study cohort) after surgical repair of type A dissection. The diameter of the dissected BCA gradually increased from 27 mm (a) to 40 mm 8 years after the onset of the dissection (b and c).
CONCLUSIONS After surgical repair of type A aortic dissection, a residual dissected supra-aortic trunk with a thrombosed FL seems to be a benign condition. Although the growth rate of aortic arch vessels is relatively slow and the incidence requiring surgical intervention for chronic dilated aortic arch vessels is considered low even in cases with patent FL, we recommend that attention be paid not only to residual dissected native aorta but also to dissected aortic arch vessels during routine aortic surveillance.
AUTHOR CONTRIBUTIONS Conception and design: TY Analysis and interpretation: TY, SK, KH Data collection: TY Writing the article: TY Critical revision of the article: TY, SK, KH, TO, HU Final approval of the article: TY, SK, KH, TO, HU Statistical analysis: TY Obtained funding: Not applicable Overall responsibility: TY
REFERENCES 1. Zielinski T, Wolkanin-Bartnik J, Janaszek-Sitkowska H, Biederman A, Rynkun D, Makowiecka-Ciesla M, et al. Persistent dissection of carotid artery in patients operated on for type A acute aortic dissectiondcarotid ultrasound follow-up. Int J Cardiol 1999;70:133-9. 2. Zurbrugg HR, Leupi F, Schupbach P, Althaus U. Duplex scanner study of carotid artery dissection following surgical treatment of aortic dissection type A. Stroke 1988;19:970-6.
3. Neri E, Sani G, Massetti M, Frati G, Buklas D, Tassi R, et al. Residual dissection of the brachiocephalic arteries: significance, management, and long-term outcome. J Thorac Cardiovasc Surg 2004;128:303-12. 4. Kieffer E, Chiche L, Koskas F, Bahnini A. Aneurysms of the innominate artery: surgical treatment of 27 patients. J Vasc Surg 2001;34:222-8. 5. Kaul P, George R, Paniagua R, Petsa A, Congiu S. Innominate truncal dissection and rupture into right pleural cavity following acute type A dissection of the aorta with right coronary ostial avulsion and inferior STEMI. Perfusion 2011;26: 435-40. 6. Tamura K, Kihara K, Chikazawa G, Sakaguchi T, Yoshitaka H. A case of dissection and rupture of the innominate artery in acute type A aortic dissection. Ann Vasc Surg 2016;9:117-9. 7. Takach TJ, Lalka SG. Innominate artery aneurysm: axial reconstruction via a cervical approach. J Vasc Surg 2007;46: 1267-9. 8. Song SW, Chang BC, Cho BK, Yi G, Youn YN, Lee S, et al. Effects of partial thrombosis on distal aorta after repair of acute DeBakey type I aortic dissection. J Thorac Cardiovasc Surg 2010;139:841-7.e1; discussion: 847. 9. Kirsch M, Soustelle C, Houel R, Hillion ML, Loisance D. Risk factor analysis for proximal and distal reoperations after surgery for acute type A aortic dissection. J Thorac Cardiovasc Surg 2002;123:318-25. 10. Zierer A, Voeller RK, Hill KE, Kouchoukos NT, Damiano RJ Jr, Moon MR. Aortic enlargement and late reoperation after repair of acute type A aortic dissection. Ann Thorac Surg 2007;84:479-86; discussion: 486-7. 11. Bachet JE, Termignon JL, Dreyfus G, Goudot B, Martinelli L, Piquois A, et al. Aortic dissection. Prevalence, cause, and results of late reoperations. J Thorac Cardiovasc Surg 1994;108:199-205; discussion: 205-6. 12. Kazui T, Washiyama N, Bashar AH, Terada H, Suzuki T, Ohkura K, et al. Surgical outcome of acute type A aortic
Journal of Vascular Surgery Volume
-,
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Yamauchi et al
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dissection: analysis of risk factors. Ann Thorac Surg 2002;74: 75-81; discussion: 81-2. 13. Trimarchi S, Tolenaar JL, Jonker FH, Murray B, Tsai TT, Eagle KA, et al. Importance of false lumen thrombosis in type B aortic dissection prognosis. J Thorac Cardiovasc Surg 2013;145: S208-12.
14. Tolenaar JL, van Keulen JW, Jonker FH, van Herwaarden JA, Verhagen HJ, Moll FL, et al. Morphologic predictors of aortic dilatation in type B aortic dissection. J Vasc Surg 2013;58:1220-5.
Submitted Sep 1, 2016; accepted Sep 30, 2016.