© 2014 Wiley Periodicals, Inc.
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Hybrid Operation for Type B Aortic Dissection Involving Distal Aortic Arch Zhang Kefeng, M.D.,*,y Pan Xudong, M.D.,y Liu Yongmin, M.D.,y Zhu Junming, M.D.,y Huang Lianjun, M.D.,y Zhang Jian, M.D.,* and Sun Lizhong, M.D.y *Department of Cardiovascular Surgery, Xuanwu Hospital, Capital Medical University, Xicheng District, Beijing, China; and yBeijing Aortic Disease Center, Beijing Anzhen Hospital, Capital Medical University, Chaoyang District, Beijing, China ABSTRACT Objectives: To retrospectively summarize clinical experiences and mid-term follow-up outcomes of hybrid operation for Type B aortic dissection involving the distal arch. Methods: From February 2009 to April 2013, 15 consecutive patients (6 males and 9 females) with Type B aortic dissection (acute, n = 10; chronic, n = 5) involving the distal aortic arch underwent a hybrid operation. Results: The patients’ median age was 62 (68–44) years. The median hospital stay was 14 (19–11) days. The hybrid procedure was performed in 15 patients comprising seven in zone 1 and eight in zone 2. Technical success was achieved in 100% and no case of paraplegia was reported. Thirty-day mortality and stroke were 0%. At a median follow-up of 12 months (range, 4–52 months), a stroke and death occurred in one patient not associated with an endograft complication. At follow-up, the overall mortality was 6.7% (1 of 15). A computed tomography scan was performed in 13 of 15 patients and thrombus formation was observed in the descending aortic false lumen excluded by the stented graft in most patients. The overall late endoleak rate was 7.7% (1 of 13); retrograde dissection occurred in no patient. There are no differences between acute and chronic aortic dissection or proximal landing zone 1 and landing zone 2 except for proximal endograft dimension. Conclusions: Hybrid operation for Type B aortic dissection involving the distal aortic arch appears safe and effective at mid-term follow-up and may extend the application of endovascular repair in the treatment of this pathology. doi:
10.1111/jocs.12330 (J Card Surg 2014;29:359–363) Conventional repair of Type B aortic dissection involving the distal arch is technically demanding and may involve cardiopulmonary bypass and deep hypothermic circulatory arrest. Despite recent repeat improvements in surgical technique, aortic repairs involving the aortic arch still have significant morbidity and mortality.1,2 Endovascular stent graft repair is an innovative, less invasive treatment method based on the principle of segmental exclusion with an endoluminal prosthesis. The use of endovascular techniques for the repair of thoracic aortic pathology has become increasingly more frequent over the last 10 years. Beginning with descending thoracic aortic aneurysms,
endovascular stent graft technology has evolved as a safe and effective treatment for thoracic Type B aortic dissection.3,4 A combined endovascular and debranching hybrid operation has been applied to treat arch pathology in recent years. However, it is uncertain as to whether the hybrid operation is suitable for Type B aortic dissections involving the distal arch, especially for chronic Type B aortic dissections. The aim of this study is to report our results for the hybrid repair for Type B aortic dissections involving the distal arch.
METHODS Patient population
Conflict of interest: All authors state that we have no conflicts of interest existing in this manuscript, and manuscript is approved by all authors for publication. Address for correspondence: Sun Lizhong, Beijing Aortic Disease Center, Beijing Anzhen Hospital, Capital Medical University, 2# Anzhen Road, Chaoyang District, Beijing 100029, China. Fax: þ86010-64456168; e-mail: [email protected] Address for correspondence: Zhang Jian, Department of Cardiovascular Surgery, Xuanwu Hospital, Capital Medical University, 45# Changchun Street, Xicheng District, Beijing 100053, China. Fax: þ86010-83198292; e-mail: [email protected]
We performed a retrospective review of our singlecenter results of all patients who underwent the hybrid operation. From February 2009 to April 2013, consecutive patients with Type B aortic dissection involving the distal aortic arch with or without an aneurysm underwent the hybrid operation. Data were collected for patient demographics, indication for intervention, risk factors, procedures, and outcomes. There were no patients with a tissue connective disorder. Permission
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J CARD SURG 2014;29:359–363
to report these cases was obtained from a local ethics committee. Hybrid procedure Most procedures were one-staged and carried out in the hybrid operating room with a portable C-arm fluoroscopy unit under general anesthesia. Some earlier cases underwent second-staged procedures with a one-day interval. The hybrid operation included right axillary artery to left axillary artery bypass with grafts (8-mm or 10-mm, GORE-TEX, Gore Medical, Flagstaff, AZ, USA) or right axillary artery to left common carotid artery and left axillary artery bypass with ‘‘Y’’ graft (8-mm or 10-mm, GORE-TEX, Gore Medical) and retrograde aortic endovascular stent graft implantation. Access to vessels was achieved through vertical neck incisions for the carotid arteries and a transverse subclavicular incision for the axillary artery. To avoid a type II endoleak after TEVAR, surgical occlusion of left carotid artery and coil embolization or closure in the proximal left subclavian artery was performed if technically achievable. TEVAR was accomplished as a sequential procedure with arch debranching bypass in all patients. A standardized TEVAR protocol was used. A diagnostic transfemoral pigtail catheter was used in all cases. True lumen access was obtained from a transfemoral approach after an inguinal cutdown. Through a 5F pigtail catheter, a 300-cm-long stiff wire (Lunderquist, Cook, Denmark) was advanced in the true lumen to the ascending aorta. Stent graft placement for dissection was designed to extend at least 15 mm proximally and distally to cover the entry site above the celiac artery to redirect blood flow down the true lumen exclusively or extend 15 mm in either direction if anatomically possible. All stent grafts were deployed in the desired position under rapid pacing without any misplacement. The endovascular repair strategy was to use two stent grafts including a proximal straight stent and a distal gradient stent with a regional overlap. Stent graft dimensions were determined by measuring the diameter of the proximal landing zone in an orthogonal view, and oversizing by >10% was avoided. Finally, a 6F pigtail catheter was placed through the left radial artery to the aortic arch for repeating angiographies. The hybrid technique is shown in Figure 1. Major measure outcome We collected perioperative data on age, hospital stay, complications, dimension, length of proximal stent graft, technique success rate, 30-day mortality, and stroke. Technique success rate was defined as no complications of the stent graft and patency of the bypass graft during the hospital stay. Thirty-day mortality and stroke were defined as ratio of mortality and stroke within 30 days postop. Follow-up The patients were followed by using enhanced computed tomography (CT) before discharge, at three
Figure 1. Three-dimensional procedure.
reconstruction
of
hybrid
months postoperatively, and annually thereafter. Complications such as neurological, renal, and respiratory morbidity were recorded. Statistical analysis We analyzed all data using SPSS 17.0 software and described the data with median value and interquartile range. We compared collected data between acute aortic dissection subgroup and chronic subgroup or landing zone 1 subgroup and landing zone 2 using Mann-Whitney U-test. Data were considered significant at the p < 0.05 level.
RESULTS Patient characteristics Fifteen patients (nine female and six male) underwent repair of a dilated Type B aortic dissection involving the distal aortic arch. The median age was 62 (68–44) years. The hospital stay ranged from 7 to 72 days. Most patients (11/15) had a history of hypertension, one patient had coronary artery disease, and one patient had diabetes. Among them, five patients with chronic aortic dissection underwent the hybrid procedure to treat proximal endoleak from a previous TEVAR technique. Another 10 patients were treated for acute Type B aortic dissection. There were seven patients who underwent right axilliary artery to left common carotid artery and left axilliary artery bypass and implantation of the stent graft in landing zone 1. Another eight patients underwent right axilliary artery to left axilliary artery bypass for implantation in
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landing zone 2. The endovascular stents included five ValiantTM stents (Medtronic, Minneapolis, MN, USA), eight ZenithTM stents (Cook Medical, Bloomington, IN, USA), one RelayTM stent (Bolton Medical, Sunrise, FL, USA), and one HerculesTM stent (Microport, Shanghai, China). Table 1 shows the patient characteristics. Table 2 shows the data comparison between the acute subgroup and chronic subgroup. Table 3 shows the data comparison between landing zone 1 subgroup and landing zone 2 subgroup. There are no differences between acute and chronic aortic dissections or landing zone 1 and landing zone 2 except for proximal stent dimensions. Table 4 shows the indication for the hybrid procedure in 15 patients with Type B aortic dissection. Major measure outcome and in-hospital morbidity Technical success was achieved in all patients (100%). No procedure was aborted due to access difficulties. All stent grafts were successfully deployed after bypass. Retrograde deployment via the femoral artery was utilized in all patients. No case of paraplegia was reported. Thirty-day mortality and stroke were both 0%. There was one patient with a hospital stay of 72 days who developed a transverse subclavicular incision infection without positive cultures.
TABLE 1 Patient Characteristics No. (%) (N = 15)
Type B Aortic Dissection Male Female Age (years) Hypertension Coronary artery disease Pulmonary disease Diabetes Previous TEVAR for Type B aortic disection Hospital stay (days) Follow-up time (months) Proximal stent dimension (mm) Proximal stent length (mm)
6 9 62 11 1 1 1 5 14 12 36 160
(40) (60) (68–44) (73) (7) (7) (7) (33) (19–11) (29–9) (38–32) (200–150)
Continuous variables described as median (75% interquartile– 25% interquartile).
361
Follow-up Clinical data were obtained by personal and telephone interviews with the patients and family members. At a median follow-up of 12 months (4–52 months), one additional fatal stroke was observed and not associated with the endograft technique. At follow-up, the overall mortality was 6.7% (1 of 15). Serial CT examinations were performed in 13 of 15 survivors who had been followed up for more than six months. One patient underwent secondary TEVAR for a distal endoleak. The overall late endoleak rate was 7.7% (1 of 13) and reintervention rate was 6.7% (1 of 15). During the follow-up period, there were no complications associated with the stent graft. No patient had a retrograde Type A aortic dissection. There were six patients in which the false lumen of the descending aorta was completely closed including two patients with chronic aortic dissection (Fig. 2). The dimension of the residual false lumen in the descending aorta significantly decreased in seven patients. DISCUSSION Type B dissections involving the distal aortic arch are characterized by a high risk of rapidly expanding false lumens and neurological complications. Umana et al.5 reported that dissections involving the aortic arch were associated with higher mortality than dissections limited to the descending aorta. We developed a new single-stage procedure of total arch replacement with stented elephant trunk implantation6 for arch pathology since 2003 and reported a satisfactory result in 31 patients with complicated Type B aortic dissections performed with this procedure.7 Hybrid procedures combine surgical bypass with endovascular arch repair.8 There are several advantages of the hybrid approach in contrast with conventional open repair. First, the hybrid procedures avoid the use of cardiopulmonary bypass and can treat those patients not qualified for open repair such as elderly with multiple comorbid conditions. Second, the hybrid procedures allow for a proximal landing zone and broaden the indications for endovascular repair for aortic diseases. Third, the hybrid procedure is less invasive.9–11 At present, few data are available on clinical outcomes of hybrid procedures in patients with aortic dissection. A recent study by Bunger @ et al.12 on hybrid
TABLE 2 Comparison Between Acute Subgroup and Chronic Subgroup Subacute Age (years) Hospital stay (days) Follow-up time (days) PSD (mm) PSL (mm)
62.5 15 12 33 158.5
Sig. (2-tailed) < 0.05 (significant difference).
(70.75–43) (19–11.5) (31.75–9.5) (36.5–31) (197.75–147.5)
Chronic 58 13 17 38 167
(66–47) (44.5–10.5) (31–8.5) (39–36) (202.0–128.5)
Sig. (2-Tailed) 0.744 0.927 0.979 0.048 0.544
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TABLE 3 Comparison Between Zone 1 Subgroup and Zone 2 Subgroup LZ1 Age (years) Hospital stay (days) Follow-up time (days) Proximal stent dimension (mm) Proximal stent length (mm)
64 13 17 38 167
(68–44) (20–11) (37–8) (40–36) (202–105)
LZ2 61 15 12 33 157
(67.5–44.75) (18.25–10.75) (24.5–10.5) (35.5–32) (187.75–150)
Sig. (2-Tailed) 0.753 0.863 0.839 0.026 0.409
Sig. (2-tailed) < 0.05 (significant difference).
TABLE 4 Indication for Hybrid Procedure in 15 Patients With Type B Aortic Dissection With Correlation to Zones 1 and 2 Indication Acute Chronic
Zone 1, No. (%)
Zone 2, No. (%)
Total
3 (30) 4 (80)
7 (70) 1 (20)
10 5
aortic arch repair in patients with Type B aortic dissection involved a total of 45 patients undergoing debranching procedures and TEVAR in 44 (98%). Their technical success rate of almost 90% and in-hospital mortality of 11% compare favorably with another review in which mortality ranges from 0% to 14.3%.13 In the report by Bunger @ et al.,12 there was a follow-up mortality rate of almost 70%, which is higher than other groups reporting of 27%,14 30%,15 and 44%.16 In a systematic review, Cao et al.13 reported that the hybrid procedure in zone 0 was associated with a mortality rate that was three times higher than the
Figure 2. Computed tomography scans of an acute Type B aortic dissection with aortic aneurysm proximal in preoperative (A), 2 months (B), and 12 months (C) after surgery. The true lumen in the descending aorta was resumed (A vs. B and C). The bypass graft was patent (B and C). The endovascular graft expanded to its full diameter (B and C), and the aorta wall had been remodeled to a normal shape owing to thrombus absorption. The false lumen was obliterated with thrombus at the diaphragmatic level (B and C).
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repair involving zone 1. Fenestrated or branched stent grafts might be a future solution for zone 0 endovascular repair in complicated Type B dissections. However, these devices are still early in development.17 Supra-aortic bypass by itself is a safe surgical procedure with a low complication rate.18 Nonfatal complications include major bleeding needing reoperation, infection, and nerve injury. In our study, nerve injury developed in no patients (0%), which is lower than reported after LSA bypass grafting (9.2%) and LSA transposition (11.2%) for occlusive disease.19 Endovascular coil embolization or closure was performed in the proximal left subclavian artery in our study to avoid potential endoleaks. We performed all bypasses originating from the right axillary artery to left axillary artery for zone 2, which was different from conventional bypasses. In our study, 30-day stroke rate was 0% and overall stroke rate was 6.7% (1 of 15), which is lower than reported.12–16 We recommend axillary bypass and endovascular closure instead of LSA or RCCA bypass and LSA transposition in complicated Type B aortic dissection. Early endoleak rates of 16%,20 27%,14 and 42%16 are reported. In our series, a lower endoleak of 7.7% (1 of 13) was observed. The proximal left common carotid artery was ligated and coil embolization or closure was performed in the proximal left subclavian artery in our procedure. This effectively excludes the arch pathology from the cerebrovascular circulation, and widens the landing zone to allow for safe manipulation of the aortic arch during delivery of the endovascular stent. In our study, the proximal stent dimension was larger in the chronic subgroup than in the acute subgroup. Thus, we used the largerdimension stent in the chronic subgroup, resulting in a satisfactory outcome. One potential limitation of our study is the small sample size of 15 patients. REFERENCES 1. Sundt TM, Orszulak TA, Cook DJ, et al: Improving results of open arch replacement. Ann Thorac Surg 2008;86:787– 796. 2. Patel HJ, Nguyen C, Diener AC, et al: Open arch reconstruction in the endovascular era: Analysis of 721 patients over 17 years. J Thorac Cardiovasc Surg 2011; 141(6):1417–1423. 3. Wilkinson DA, Patel HJ, Williams DM, et al: Early open and endovascular thoracic aortic repair for complicated type B aortic dissection. Ann Thorac Surg 2013;96(1):23–30. 4. Weidenhagen R, Bombien R, Meimarakis G, et al: Management of thoracic aortic lesions—The future is endovascular. Vasa 2012;41(3):163–176.
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5. Umana JP, Lai DT, Mitchell RS, et al: Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections? J Thorac Cardiovasc Surg 2002; 124:896–910. 6. Sun L, Qi R, Zhu J, et al: Total arch replacement combined with stented elephant trunk implantation: A new ‘‘standard’’ therapy for type a dissection involving repair of the aortic arch? Circulation 2011;123(9):971–978. 7. Li B, Sun L, Chang Q, et al: Total arch replacement with stented elephant trunk technique: A proposed treatment for complicated Stanford type B aortic dissection. J Card Surg 2009;24(6):704–709. 8. Kuratani T, Sawa Y: Current strategy of endovascular aortic repair for thoracic aortic aneurysms. Gen Thorac Cardiovasc Surg 2010;58(8):393–398. 9. Benedik J, Tsagakis K, Kamler M, et al: Complex acute dissection of the aortic arch—A novel hybrid concept for one stage surgical repair. Acta Chir Belg 2010;110(2): 178–184. 10. Antoniou GA, Mireskandari M, Bicknell CD, et al: Hybrid repair of the aortic arch in patients with extensive aortic disease. Eur J Vasc Endovasc Surg 2010;40(6):715–721. 11. Eagleton MJ, Greenberg RK: Hybrid procedures for the treatment of aortic arch aneurysms. J Cardiovasc Surg (Torino) 2010;51(6):807–819. 12. B@ unger CM, Kische S, Liebold A, et al: Hybrid aortic arch repair for complicated type B aortic dissection. J Vasc Surg 2013;58(6):1490–1496. 13. Cao P, De Rango P, Czerny M, et al: Systematic review of clinical outcomes in hybrid procedures for aortic arch dissections and other arch diseases. J Thorac Cardiovasc Surg 2012;144:1286e2–1300e2. 14. Geisbusch P, Kotelis D, Eschner MM, et al: Complications after aortic arch hybrid repair. J Vasc Surg 2011;53:935– 941. 15. Vallejo N, Rodriguez-Lopez JA, Heidari P, et al: Hybrid repair of thoracic aortic lesions for zone 0 and 1 in high risk patients. J Vasc Surg 2011;55:318–325. 16. Antoniou GA, Mireskandari M, Bicknell CD, et al: Hybrid repair of the aortic arch in patients with extensive aortic disease. Eur J Vasc Endovasc Surg 2010;40:715–721. 17. Sobocinski J, Hertault A, Tyrrell M, et al: Chronic type B dissections: Are fenestrated and branched endografts an option? J Cardiovasc Surg (Torino) 2013;54(1 Suppl 1):97–107. 18. Byrne J, Darling RC, Roddy SP, et al: Long term outcome for extra-anatomic arch reconstruction. An analysis of 143 procedures. Eur J Vasc Endovasc Surg 2007;34:444– 450. 19. Cina` CS, Safar HA, Lagana` A, et al: Subclavian carotid transposition and bypass grafting: Consecutive cohort study and systematic review. J Vasc Surg 2002;35:422– 429. 20. Lotfi S, Clough RE, Ali T, et al: Hybrid repair of complex thoracic aortic arch pathology: Long-term outcomes of extra-anatomic bypass grafting of the supra-aortic trunk. Cardiovasc Interv Radiol 2013;36:46–55.
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Hybrid Operation for Type B Aortic Dissection Involving Distal Aortic Arch Zhang Kefeng, M.D.,*,y Pan Xudong, M.D.,y Liu Yongmin, M.D.,y Zhu Junming, M.D.,y Huang Lianjun, M.D.,y Zhang Jian, M.D.,* and Sun Lizhong, M.D.y *Department of Cardiovascular Surgery, Xuanwu Hospital, Capital Medical University, Xicheng District, Beijing, China; and yBeijing Aortic Disease Center, Beijing Anzhen Hospital, Capital Medical University, Chaoyang District, Beijing, China ABSTRACT Objectives: To retrospectively summarize clinical experiences and mid-term follow-up outcomes of hybrid operation for Type B aortic dissection involving the distal arch. Methods: From February 2009 to April 2013, 15 consecutive patients (6 males and 9 females) with Type B aortic dissection (acute, n = 10; chronic, n = 5) involving the distal aortic arch underwent a hybrid operation. Results: The patients’ median age was 62 (68–44) years. The median hospital stay was 14 (19–11) days. The hybrid procedure was performed in 15 patients comprising seven in zone 1 and eight in zone 2. Technical success was achieved in 100% and no case of paraplegia was reported. Thirty-day mortality and stroke were 0%. At a median follow-up of 12 months (range, 4–52 months), a stroke and death occurred in one patient not associated with an endograft complication. At follow-up, the overall mortality was 6.7% (1 of 15). A computed tomography scan was performed in 13 of 15 patients and thrombus formation was observed in the descending aortic false lumen excluded by the stented graft in most patients. The overall late endoleak rate was 7.7% (1 of 13); retrograde dissection occurred in no patient. There are no differences between acute and chronic aortic dissection or proximal landing zone 1 and landing zone 2 except for proximal endograft dimension. Conclusions: Hybrid operation for Type B aortic dissection involving the distal aortic arch appears safe and effective at mid-term follow-up and may extend the application of endovascular repair in the treatment of this pathology. doi:
10.1111/jocs.12330 (J Card Surg 2014;29:359–363) Conventional repair of Type B aortic dissection involving the distal arch is technically demanding and may involve cardiopulmonary bypass and deep hypothermic circulatory arrest. Despite recent repeat improvements in surgical technique, aortic repairs involving the aortic arch still have significant morbidity and mortality.1,2 Endovascular stent graft repair is an innovative, less invasive treatment method based on the principle of segmental exclusion with an endoluminal prosthesis. The use of endovascular techniques for the repair of thoracic aortic pathology has become increasingly more frequent over the last 10 years. Beginning with descending thoracic aortic aneurysms,
endovascular stent graft technology has evolved as a safe and effective treatment for thoracic Type B aortic dissection.3,4 A combined endovascular and debranching hybrid operation has been applied to treat arch pathology in recent years. However, it is uncertain as to whether the hybrid operation is suitable for Type B aortic dissections involving the distal arch, especially for chronic Type B aortic dissections. The aim of this study is to report our results for the hybrid repair for Type B aortic dissections involving the distal arch.
METHODS Patient population
Conflict of interest: All authors state that we have no conflicts of interest existing in this manuscript, and manuscript is approved by all authors for publication. Address for correspondence: Sun Lizhong, Beijing Aortic Disease Center, Beijing Anzhen Hospital, Capital Medical University, 2# Anzhen Road, Chaoyang District, Beijing 100029, China. Fax: þ86010-64456168; e-mail: [email protected] Address for correspondence: Zhang Jian, Department of Cardiovascular Surgery, Xuanwu Hospital, Capital Medical University, 45# Changchun Street, Xicheng District, Beijing 100053, China. Fax: þ86010-83198292; e-mail: [email protected]
We performed a retrospective review of our singlecenter results of all patients who underwent the hybrid operation. From February 2009 to April 2013, consecutive patients with Type B aortic dissection involving the distal aortic arch with or without an aneurysm underwent the hybrid operation. Data were collected for patient demographics, indication for intervention, risk factors, procedures, and outcomes. There were no patients with a tissue connective disorder. Permission
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J CARD SURG 2014;29:359–363
to report these cases was obtained from a local ethics committee. Hybrid procedure Most procedures were one-staged and carried out in the hybrid operating room with a portable C-arm fluoroscopy unit under general anesthesia. Some earlier cases underwent second-staged procedures with a one-day interval. The hybrid operation included right axillary artery to left axillary artery bypass with grafts (8-mm or 10-mm, GORE-TEX, Gore Medical, Flagstaff, AZ, USA) or right axillary artery to left common carotid artery and left axillary artery bypass with ‘‘Y’’ graft (8-mm or 10-mm, GORE-TEX, Gore Medical) and retrograde aortic endovascular stent graft implantation. Access to vessels was achieved through vertical neck incisions for the carotid arteries and a transverse subclavicular incision for the axillary artery. To avoid a type II endoleak after TEVAR, surgical occlusion of left carotid artery and coil embolization or closure in the proximal left subclavian artery was performed if technically achievable. TEVAR was accomplished as a sequential procedure with arch debranching bypass in all patients. A standardized TEVAR protocol was used. A diagnostic transfemoral pigtail catheter was used in all cases. True lumen access was obtained from a transfemoral approach after an inguinal cutdown. Through a 5F pigtail catheter, a 300-cm-long stiff wire (Lunderquist, Cook, Denmark) was advanced in the true lumen to the ascending aorta. Stent graft placement for dissection was designed to extend at least 15 mm proximally and distally to cover the entry site above the celiac artery to redirect blood flow down the true lumen exclusively or extend 15 mm in either direction if anatomically possible. All stent grafts were deployed in the desired position under rapid pacing without any misplacement. The endovascular repair strategy was to use two stent grafts including a proximal straight stent and a distal gradient stent with a regional overlap. Stent graft dimensions were determined by measuring the diameter of the proximal landing zone in an orthogonal view, and oversizing by >10% was avoided. Finally, a 6F pigtail catheter was placed through the left radial artery to the aortic arch for repeating angiographies. The hybrid technique is shown in Figure 1. Major measure outcome We collected perioperative data on age, hospital stay, complications, dimension, length of proximal stent graft, technique success rate, 30-day mortality, and stroke. Technique success rate was defined as no complications of the stent graft and patency of the bypass graft during the hospital stay. Thirty-day mortality and stroke were defined as ratio of mortality and stroke within 30 days postop. Follow-up The patients were followed by using enhanced computed tomography (CT) before discharge, at three
Figure 1. Three-dimensional procedure.
reconstruction
of
hybrid
months postoperatively, and annually thereafter. Complications such as neurological, renal, and respiratory morbidity were recorded. Statistical analysis We analyzed all data using SPSS 17.0 software and described the data with median value and interquartile range. We compared collected data between acute aortic dissection subgroup and chronic subgroup or landing zone 1 subgroup and landing zone 2 using Mann-Whitney U-test. Data were considered significant at the p < 0.05 level.
RESULTS Patient characteristics Fifteen patients (nine female and six male) underwent repair of a dilated Type B aortic dissection involving the distal aortic arch. The median age was 62 (68–44) years. The hospital stay ranged from 7 to 72 days. Most patients (11/15) had a history of hypertension, one patient had coronary artery disease, and one patient had diabetes. Among them, five patients with chronic aortic dissection underwent the hybrid procedure to treat proximal endoleak from a previous TEVAR technique. Another 10 patients were treated for acute Type B aortic dissection. There were seven patients who underwent right axilliary artery to left common carotid artery and left axilliary artery bypass and implantation of the stent graft in landing zone 1. Another eight patients underwent right axilliary artery to left axilliary artery bypass for implantation in
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landing zone 2. The endovascular stents included five ValiantTM stents (Medtronic, Minneapolis, MN, USA), eight ZenithTM stents (Cook Medical, Bloomington, IN, USA), one RelayTM stent (Bolton Medical, Sunrise, FL, USA), and one HerculesTM stent (Microport, Shanghai, China). Table 1 shows the patient characteristics. Table 2 shows the data comparison between the acute subgroup and chronic subgroup. Table 3 shows the data comparison between landing zone 1 subgroup and landing zone 2 subgroup. There are no differences between acute and chronic aortic dissections or landing zone 1 and landing zone 2 except for proximal stent dimensions. Table 4 shows the indication for the hybrid procedure in 15 patients with Type B aortic dissection. Major measure outcome and in-hospital morbidity Technical success was achieved in all patients (100%). No procedure was aborted due to access difficulties. All stent grafts were successfully deployed after bypass. Retrograde deployment via the femoral artery was utilized in all patients. No case of paraplegia was reported. Thirty-day mortality and stroke were both 0%. There was one patient with a hospital stay of 72 days who developed a transverse subclavicular incision infection without positive cultures.
TABLE 1 Patient Characteristics No. (%) (N = 15)
Type B Aortic Dissection Male Female Age (years) Hypertension Coronary artery disease Pulmonary disease Diabetes Previous TEVAR for Type B aortic disection Hospital stay (days) Follow-up time (months) Proximal stent dimension (mm) Proximal stent length (mm)
6 9 62 11 1 1 1 5 14 12 36 160
(40) (60) (68–44) (73) (7) (7) (7) (33) (19–11) (29–9) (38–32) (200–150)
Continuous variables described as median (75% interquartile– 25% interquartile).
361
Follow-up Clinical data were obtained by personal and telephone interviews with the patients and family members. At a median follow-up of 12 months (4–52 months), one additional fatal stroke was observed and not associated with the endograft technique. At follow-up, the overall mortality was 6.7% (1 of 15). Serial CT examinations were performed in 13 of 15 survivors who had been followed up for more than six months. One patient underwent secondary TEVAR for a distal endoleak. The overall late endoleak rate was 7.7% (1 of 13) and reintervention rate was 6.7% (1 of 15). During the follow-up period, there were no complications associated with the stent graft. No patient had a retrograde Type A aortic dissection. There were six patients in which the false lumen of the descending aorta was completely closed including two patients with chronic aortic dissection (Fig. 2). The dimension of the residual false lumen in the descending aorta significantly decreased in seven patients. DISCUSSION Type B dissections involving the distal aortic arch are characterized by a high risk of rapidly expanding false lumens and neurological complications. Umana et al.5 reported that dissections involving the aortic arch were associated with higher mortality than dissections limited to the descending aorta. We developed a new single-stage procedure of total arch replacement with stented elephant trunk implantation6 for arch pathology since 2003 and reported a satisfactory result in 31 patients with complicated Type B aortic dissections performed with this procedure.7 Hybrid procedures combine surgical bypass with endovascular arch repair.8 There are several advantages of the hybrid approach in contrast with conventional open repair. First, the hybrid procedures avoid the use of cardiopulmonary bypass and can treat those patients not qualified for open repair such as elderly with multiple comorbid conditions. Second, the hybrid procedures allow for a proximal landing zone and broaden the indications for endovascular repair for aortic diseases. Third, the hybrid procedure is less invasive.9–11 At present, few data are available on clinical outcomes of hybrid procedures in patients with aortic dissection. A recent study by Bunger @ et al.12 on hybrid
TABLE 2 Comparison Between Acute Subgroup and Chronic Subgroup Subacute Age (years) Hospital stay (days) Follow-up time (days) PSD (mm) PSL (mm)
62.5 15 12 33 158.5
Sig. (2-tailed) < 0.05 (significant difference).
(70.75–43) (19–11.5) (31.75–9.5) (36.5–31) (197.75–147.5)
Chronic 58 13 17 38 167
(66–47) (44.5–10.5) (31–8.5) (39–36) (202.0–128.5)
Sig. (2-Tailed) 0.744 0.927 0.979 0.048 0.544
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TABLE 3 Comparison Between Zone 1 Subgroup and Zone 2 Subgroup LZ1 Age (years) Hospital stay (days) Follow-up time (days) Proximal stent dimension (mm) Proximal stent length (mm)
64 13 17 38 167
(68–44) (20–11) (37–8) (40–36) (202–105)
LZ2 61 15 12 33 157
(67.5–44.75) (18.25–10.75) (24.5–10.5) (35.5–32) (187.75–150)
Sig. (2-Tailed) 0.753 0.863 0.839 0.026 0.409
Sig. (2-tailed) < 0.05 (significant difference).
TABLE 4 Indication for Hybrid Procedure in 15 Patients With Type B Aortic Dissection With Correlation to Zones 1 and 2 Indication Acute Chronic
Zone 1, No. (%)
Zone 2, No. (%)
Total
3 (30) 4 (80)
7 (70) 1 (20)
10 5
aortic arch repair in patients with Type B aortic dissection involved a total of 45 patients undergoing debranching procedures and TEVAR in 44 (98%). Their technical success rate of almost 90% and in-hospital mortality of 11% compare favorably with another review in which mortality ranges from 0% to 14.3%.13 In the report by Bunger @ et al.,12 there was a follow-up mortality rate of almost 70%, which is higher than other groups reporting of 27%,14 30%,15 and 44%.16 In a systematic review, Cao et al.13 reported that the hybrid procedure in zone 0 was associated with a mortality rate that was three times higher than the
Figure 2. Computed tomography scans of an acute Type B aortic dissection with aortic aneurysm proximal in preoperative (A), 2 months (B), and 12 months (C) after surgery. The true lumen in the descending aorta was resumed (A vs. B and C). The bypass graft was patent (B and C). The endovascular graft expanded to its full diameter (B and C), and the aorta wall had been remodeled to a normal shape owing to thrombus absorption. The false lumen was obliterated with thrombus at the diaphragmatic level (B and C).
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repair involving zone 1. Fenestrated or branched stent grafts might be a future solution for zone 0 endovascular repair in complicated Type B dissections. However, these devices are still early in development.17 Supra-aortic bypass by itself is a safe surgical procedure with a low complication rate.18 Nonfatal complications include major bleeding needing reoperation, infection, and nerve injury. In our study, nerve injury developed in no patients (0%), which is lower than reported after LSA bypass grafting (9.2%) and LSA transposition (11.2%) for occlusive disease.19 Endovascular coil embolization or closure was performed in the proximal left subclavian artery in our study to avoid potential endoleaks. We performed all bypasses originating from the right axillary artery to left axillary artery for zone 2, which was different from conventional bypasses. In our study, 30-day stroke rate was 0% and overall stroke rate was 6.7% (1 of 15), which is lower than reported.12–16 We recommend axillary bypass and endovascular closure instead of LSA or RCCA bypass and LSA transposition in complicated Type B aortic dissection. Early endoleak rates of 16%,20 27%,14 and 42%16 are reported. In our series, a lower endoleak of 7.7% (1 of 13) was observed. The proximal left common carotid artery was ligated and coil embolization or closure was performed in the proximal left subclavian artery in our procedure. This effectively excludes the arch pathology from the cerebrovascular circulation, and widens the landing zone to allow for safe manipulation of the aortic arch during delivery of the endovascular stent. In our study, the proximal stent dimension was larger in the chronic subgroup than in the acute subgroup. Thus, we used the largerdimension stent in the chronic subgroup, resulting in a satisfactory outcome. One potential limitation of our study is the small sample size of 15 patients. REFERENCES 1. Sundt TM, Orszulak TA, Cook DJ, et al: Improving results of open arch replacement. Ann Thorac Surg 2008;86:787– 796. 2. Patel HJ, Nguyen C, Diener AC, et al: Open arch reconstruction in the endovascular era: Analysis of 721 patients over 17 years. J Thorac Cardiovasc Surg 2011; 141(6):1417–1423. 3. Wilkinson DA, Patel HJ, Williams DM, et al: Early open and endovascular thoracic aortic repair for complicated type B aortic dissection. Ann Thorac Surg 2013;96(1):23–30. 4. Weidenhagen R, Bombien R, Meimarakis G, et al: Management of thoracic aortic lesions—The future is endovascular. Vasa 2012;41(3):163–176.
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5. Umana JP, Lai DT, Mitchell RS, et al: Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections? J Thorac Cardiovasc Surg 2002; 124:896–910. 6. Sun L, Qi R, Zhu J, et al: Total arch replacement combined with stented elephant trunk implantation: A new ‘‘standard’’ therapy for type a dissection involving repair of the aortic arch? Circulation 2011;123(9):971–978. 7. Li B, Sun L, Chang Q, et al: Total arch replacement with stented elephant trunk technique: A proposed treatment for complicated Stanford type B aortic dissection. J Card Surg 2009;24(6):704–709. 8. Kuratani T, Sawa Y: Current strategy of endovascular aortic repair for thoracic aortic aneurysms. Gen Thorac Cardiovasc Surg 2010;58(8):393–398. 9. Benedik J, Tsagakis K, Kamler M, et al: Complex acute dissection of the aortic arch—A novel hybrid concept for one stage surgical repair. Acta Chir Belg 2010;110(2): 178–184. 10. Antoniou GA, Mireskandari M, Bicknell CD, et al: Hybrid repair of the aortic arch in patients with extensive aortic disease. Eur J Vasc Endovasc Surg 2010;40(6):715–721. 11. Eagleton MJ, Greenberg RK: Hybrid procedures for the treatment of aortic arch aneurysms. J Cardiovasc Surg (Torino) 2010;51(6):807–819. 12. B@ unger CM, Kische S, Liebold A, et al: Hybrid aortic arch repair for complicated type B aortic dissection. J Vasc Surg 2013;58(6):1490–1496. 13. Cao P, De Rango P, Czerny M, et al: Systematic review of clinical outcomes in hybrid procedures for aortic arch dissections and other arch diseases. J Thorac Cardiovasc Surg 2012;144:1286e2–1300e2. 14. Geisbusch P, Kotelis D, Eschner MM, et al: Complications after aortic arch hybrid repair. J Vasc Surg 2011;53:935– 941. 15. Vallejo N, Rodriguez-Lopez JA, Heidari P, et al: Hybrid repair of thoracic aortic lesions for zone 0 and 1 in high risk patients. J Vasc Surg 2011;55:318–325. 16. Antoniou GA, Mireskandari M, Bicknell CD, et al: Hybrid repair of the aortic arch in patients with extensive aortic disease. Eur J Vasc Endovasc Surg 2010;40:715–721. 17. Sobocinski J, Hertault A, Tyrrell M, et al: Chronic type B dissections: Are fenestrated and branched endografts an option? J Cardiovasc Surg (Torino) 2013;54(1 Suppl 1):97–107. 18. Byrne J, Darling RC, Roddy SP, et al: Long term outcome for extra-anatomic arch reconstruction. An analysis of 143 procedures. Eur J Vasc Endovasc Surg 2007;34:444– 450. 19. Cina` CS, Safar HA, Lagana` A, et al: Subclavian carotid transposition and bypass grafting: Consecutive cohort study and systematic review. J Vasc Surg 2002;35:422– 429. 20. Lotfi S, Clough RE, Ali T, et al: Hybrid repair of complex thoracic aortic arch pathology: Long-term outcomes of extra-anatomic bypass grafting of the supra-aortic trunk. Cardiovasc Interv Radiol 2013;36:46–55.
