Innominate Artery Translocation with Hemiarch Replacement Strategy for Acute Type A Aortic Dissection: a Single-Center Study

Abstract

Background Aggressive surgical methods for acute type A aortic dissection (ATAD) can cause extended operating times and postoperative complications. less extensive techniques may increase the risk of needing further aortic reintervention. To prevent the need for extensive aortic arch surgery and subsequent re-sternotomy, hemiarch replacement (HAR) with innominate artery (a.) translocation is performed to create a suitable proximal landing zone for future endovascular repair.

Methods Retrospective study of 112 patients with ATAD who underwent aortic surgery from January 2009 to December 2020. Forty-one patients underwent HAR with innominate artery translocation, 16 underwent total arch replacement (TAR), and 55 underwent only HAR. Multivariable Cox regression and logistic regression analyses were used to study the outcomes and risk factors.

Results The TAR group had a higher incidence of postoperative acute kidney injury. The overall mortality rate of the TAR group was 25%, compared with 20% in the HAR group and 14.6% in the translocation group. The 5-year overall survival rates for the groups were 81.9%, 75.0%, and 77.7%, respectively. False lumen thrombosis at the aortic arch and descending aorta level were factors associated with reduced mortality in both univariable and multivariable analyses. The translocation group had a significantly higher reintervention rate of 41.5% compared with the TAR and HAR groups, with rates of 31.3% and 16.4%, respectively. The median reintervention time for the translocation group was 4.72 years.

Conclusion Despite the innominate translocation technique having a higher reintervention rate, it had similar mortality outcomes to HAR and TAR. Thus, it could be a more convenient option for reintervention, including creating a proximal landing zone, which could benefit patients needing endovascular repair.

Keywords

acute type A aortic dissection - hemiarch replacement - total arch replacement - surgical technique

Introduction

The ascending aorta is always replaced in cases of acute Stanford type A aortic dissection (ATAD). However, the key question is determining the appropriate location for the distal anastomosis site. A range of surgical options is available, spanning from less extensive procedures to highly aggressive operations, which include ascending aortic replacement, Hemiarch replacement (HAR), Total arch replacement (TAR), and TAR with frozen elephant trunk (FET).

An aggressive procedure has the potential to correct most of the lesions associated with aortic dissection. It may also reduce the need for further aortic procedures, such as redo aortic arch replacement or endovascular surgery.[1] [2] However, the aggressive procedure requires higher surgical expertise, increased resource usage, and a longer operative time.[3]

In contrast, less extensive procedures have the advantage of requiring simpler surgical techniques, fewer surgical resources, and a shorter operative time. However, further aortic reintervention may be necessary, as these techniques cannot correct all aortic pathologies.[4] [5] Residual dissection may remain at the aortic arch and descending aorta, and some patients may require redo open surgery, which carries a higher operative risk because the residual disease is not suitable for endovascular treatment.

Current guidelines recommend that ATAD surgery begins with HAR at a minimum.[6] [7] Several studies have shown that HAR has a lower incidence of postoperative adverse outcomes than TAR.[8] [9] [10] [11] Therefore, performing less extensive surgery using HAR and preparing the proximal landing zone for further endovascular treatment by creating innominate artery (brachiocephalic a.) translocation is another treatment option. If reintervention is indicated, thoracic endovascular repair can be performed more easily and has a suitable proximal landing zone.

The aim of this study was to compare the postoperative outcomes of standard conventional technique (HAR), further endovascular preparing technique (HAR with innominate translocation), and highly aggressive treatment technique (TAR) in both the short- and mid-term aspects.

Materials and Methods

Patients

The study design was a retrospective, with collection of registry data from Maharaj Nakorn Chiang Mai Hospital, Faculty of Medicine, Chiang Mai University, Thailand. The study was approved by the Research Ethics Committee Panel 5 of the Faculty of Medicine, Chiang Mai University, ID: SUR-2563-07654. We analyzed all consecutive patients 18 years old or older who were diagnosed with ATAD and were referred to the hospital for emergent surgical treatment from January 2009 through December 2020. The partial arch replacement technique was not performed at our institute. The TAR with an FET was excluded from the study because there was no need to perform a second reintervention through endovascular means.

The 112 cases of ATAD included in this study were divided into three groups: patients who underwent HAR with innominate artery translocation, translocation group (n = 41, 36.61%); patients who underwent TAR, TAR group (n = 16, 14.29%); and patients who underwent conventional HAR, HAR group (n = 55, 49.10%).

Operative Techniques and Procedures

Hemiarch Replacement

After median sternotomy, cardiopulmonary bypass (CPB) was established with arterial inflow via peripheral cannulation (usually femoral aortic cannulation, or Rt. Subclavian aortic cannulation, or both). Venous drainage was obtained from a two-stage venous cannula. Myocardial protection was performed with cold Bretschneider solution (Custodiol® Essential Pharmaceuticals, LLC). Deep hypothermia (20–24 °C) with selective cerebral perfusion was used as a neuroprotective strategy (by direct insertion of the cerebral perfusion cannula into innominate artery, left common carotid artery, and left subclavian artery) after opening the hemiarch. In some cases, the left subclavian artery cannot be accessed, and the cannula cannot be inserted. In such situations, the cannula is inserted into the left common carotid artery, leaving the left subclavian without cannulation. Near-infrared spectroscopy was used for monitoring.

In the HAR technique, the distal anastomosis was performed after a complete transection of the aortic arch proximal to the origin of the innominate artery on the greater curve of the arch and below the left subclavian artery on the lesser curve of the arch. Distal and proximal anastomosis sites of the dissection were prepared before connecting to a synthetic Dacron graft by using either a double sandwich technique with Teflon felt or an adventitia inversion technique. Then the graft was anastomosed to the prepared arch and ascending aorta with a 3–0 polypropylene running suture ([Fig. 1A]).

Fig. 1 Illustration of the surgical procedure for acute type A aortic dissection. (A) Hemiarch replacement. (B) hemiarch replacement with innominate artery translocation. (C) Total arch replacement.

Innominate Artery Translocation

After a median sternotomy, CPB was established with arterial inflow via right subclavian aortic cannulation, or with an additional arterial cannulation in the femoral artery. The initial technique was similar to the HAR technique, but during hemiarch opening, the selective cerebral perfusion method differed. The innominate artery was clamped, and the cerebral cannula was inserted directly into the left common carotid and left subclavian.

To create a proper proximal landing zone, during systemic circulatory arrest, the origin of the innominate artery was transected and the innominate setup closed with 5–0 polypropylene. One selective cerebral perfusion cannula was inserted into the cut innominate artery. A small Dacron graft (size 12–18 mm) was anastomosed to the cut innominate artery. After finishing the aortic distal anastomosis (or both proximal and distal anastomoses), the innominate Dacron graft was connected to the main aortic Dacron graft ([Fig. 1B]). The innominate Dacron graft should be anastomosed as proximally as possible to create a proximal landing zone for future endovascular interventions. This positioning allows for a proximal landing zone with a length of around 2 to 4 cm from the translocated innominate branch to the anastomosis of the HAR.

Total Arch Replacement

After median sternotomy, CPB was established with arterial inflow via peripheral cannulation (usually femoral aortic cannulation, or Rt. Subclavian aortic cannulation, or both). Venous drainage was obtained from a two-stage venous cannula. Myocardial protection was performed with a cold Bretschneider solution. Deep hypothermia (20–24 °C) with selective cerebral perfusion was used by direct insertion of the cerebral perfusion cannula into innominate artery, left common carotid artery, and left subclavian artery after opening the arch.

The distal anastomosis was performed after a complete transection of the proximal descending aorta (Ishimaru's zone 3). Distal and proximal anastomosis sites of the dissection were prepared for TAR. Then, the distal part of the commercial or homemade quadrifurcated graft was used to connect to the descending aorta with 3–0 polypropylene. This was followed by anastomosis of the left subclavian artery, left common carotid artery, innominate artery, and the prepared ascending aorta ([Fig. 1C]).

Concomitant Procedures

Concomitant procedures included aortic root replacement in 33 patients, aortic valve-sparing root replacement in 10 patients, and coronary artery bypass grafting in 17 patients.

Follow-up

After the hospital discharge, the first-line drugs were β-blockade for control of hypertension and statins for treating dyslipidemia. Smoking was advised to be stopped in all patients. Computed tomography angiography (CTA) of the aorta was the first choice for following the progression of residual disease.

Definition

The primary endpoints included 30-day mortality, which was defined as any death occurring within 30 days of the operation or before discharge from the hospital. Other primary endpoints were overall death, which referred to all-cause mortality; aortic-related death, which was defined as death resulting from aortic causes after the operation (such as rupture, pseudoaneurysm rupture, tamponade, and malperfusion); midterm (5-year) survival; and reintervention, which included any subsequent aortic surgery (both endovascular and open) following the initial aortic operation.

The secondary endpoints include postoperative results and complications (such as arrhythmia, neurological problems, renal problems, septicemia, bleeding and transfusion, intensive care unit [ICU] stay, and hospital stay), as well as risk factors related to death.

Statistical Analysis

Statistical analyses were performed on the STATA version 16.1. The sample size was calculated based on studies in which the outcomes were similar to this study.[5] [8] [10] Analysis of variance (ANOVA) with Bonferroni correction was applied for comparisons of continuous variables between the three groups. χ² test was applied for groups of categorical comparisons. Long-term overall survival, freedom from aortic-related death, and reintervention were presented by Kaplan–Meier curves. The differences between the three groups were analyzed using the log-rank test and multivariable Cox regression analysis adjusted for sex, age, prior cerebrovascular accident, CPB time, aortic clamp time, circulatory arrest time, and lowest temperature variables. Independent risk factors for reintervention were identified using univariable and multivariable logistic regression analyses. In all statistical tests, differences between the groups were considered significant at p < 0.05.

Results

Baseline Characteristics and Perioperative Data

[Table 1] shows that there were no significant differences between the three groups, except for a statistically significant difference in the incidence of preoperative old cerebrovascular accidents. However, the operative data in [Table 2] revealed that the CPB time, aortic clamp time, and systemic circulatory arrest time were all significantly longer in the TAR, innominate, and HAR groups in that order.

Table 1 Patients' baseline characteristics

Variables	Innominate translocation n = 41	Total arch replacement n = 16	Hemiarch replacement n = 55	p-Value
Age (years)	58.3 ± 13.1	57.3 ± 11.3	55.5 ± 16.2	0.646
Male	26 (63.4)	11 (68.8)	34 (61.8)	0.929
Weight (kg)	67.2 ± 13.9	68.2 ± 14.8	64.7 ± 13.5	0.548
Height (cm)	164.7 ± 7.3	165.3 ± 5.6	164.2 ± 8.8	0.102
Euro score II (%)	27.2 ± 10.5	23.8 ± 14.8	24.2 ± 8.6	0.322
Preoperative left ventricular ejection fraction (%)	50.2 ± 11.1	50.9 ± 10.6	51.5 ± 10.9	0.977
Preoperative aortic valve regurgitation	28 (68.3)	6 (37.5)	29 (52.7)	0.083
Malperfusion	10 (24.4)	7 (43.8)	20 (36.3)	0.288
Hemopericardium	17 (41.5)	11 (68.8)	35 (63.6)	0.053
Neurologic symptom	6 (14.6)	3 (18.8)	5 (9.1)	0.515
Entry tear site (Ishimaru's zone):
Zone 0	30 (73.1)	10 (62.5)	45 (81.8)	0.248
Zone 1	4 (9.8)	1 (6.3)	7 (12.7)	0.739
Zone 2	4 (9.8)	4 (25.0)	3 (5.5)	0.069
Zone 3	3 (7.3)	1 (6.3)	0 (0)	0.133
Arch branch dissection	32 (80)	13 (81.3)	34 (68.1)	0.097
Hypertension	37 (90.2)	16 (100)	48 (87.3)	0.322
Diabetes mellitus type 2	8 (19.5)	6 (37.5)	7 (12.7)	0.081
Old cerebrovascular accident	3 (7.3)	4 (25.0)	1 (1.8)	0.007
Chronic kidney disease	8 (19.5)	6 (37.5)	23 (41.8)	0.066
Marfan's syndrome	2 (4.9)	0 (0)	5 (9.1)	0.376

Data are presented as mean ± standard deviation or as numbers and percentages.

p < 0.05 was considered statistically significant.

Table 2 Perioperative and postoperative data

Variables	Innominate translocation n = 41	Total arch replacement n = 16	Hemiarch replacement n = 55	p-Value
Isolate aortic surgery	30 (70.2)	9 (56.3)	33 (60)	0.317
Concomitant surgery:
Root replacement	13 (31.7)	5 (31.3)	15 (27.3)	0.882
aortic valve-sparing root replacement	4 (9.8)	1 (6.3)	5 (9.1)	0.915
coronary artery bypass grafting	5 (12.2)	3 (18.7)	9 (16.4)	0.778
Techniques for distal anastomosis				0.884
Adventitia inversion	23 (56.1)	10 (62.5)	33 (60.0)
Double felt sandwich	18 (43.9)	6 (37.5)	22 (40.0)
Ascending graft diameter (mm)	28.5 ± 2.1	29.75 ± 1.8	29 ± 2.0	0.680
Innominate graft diameter (mm)	14.8 ± 3.0	–	–	–
Femoral cannulation	33 (88.5)	13 (81.3)	47 (85.5)	0.797
Axillary canulation	32 (78.5)	14 (87.5)	47 (85.5)	0.555
Operative time (min)	410 ± 124.8	393.1 ± 108.1	356 (97.7)	0.253
cardiopulmonary bypass time (min)	241.7 ± 77.6	286.3 ± 97.6	191.4 ± 53.0	0.003
Clamp time (min)	149.6 ± 77.6	205.4 ± 102.3	121.5 ± 45.3	<0.001
Circulatory arrest time (min)	45.6 ± 18.3	56.1 ± 27.8	38.1 ± 9.4	<0.001
Lowest temperature (°C)	23.1 ± 1.6	23.7 ± 2.8	23.2 ± 1.7	0.014
Drain first 24 hours (ml)	587.8 ± 499.7	986.9 ± 796.8	611.7 ± 653.9	0.058
packed red cell (PRC) transfusion	27 (65.85)	12 (75)	45 (81.8)	0.203
Unit of PRC used (unit)	3.8 ± 2.8	5.4 ± 2.3	3.4 ± 2.5	0.690
Postoperative arrhythmia	19 (46.3)	11 (68.8)	26 (47.3)	0.268
Stroke	9 (21.9)	2 (12.5)	7 (12.7)	0.436
Paraplegia	3 (7.3)	1 (6.3)	6 (10.9)	0.764
Delirium	7 (17.1)	3 (18.8)	5 (9.1)	0.416
Acute kidney injury	24 (58.5)	12 (75)	47 (52.4)	0.012
Hemodialysis	7 (17.1)	3 (18.8)	13 (23.6)	0.720
Severe septicemia	2 (4.9)	2 (12.5)	4 (7.3)	0.603
Early reoperative from bleeding	6 (14.6)	3 (18.8)	7 (12.7)	0.830
Ventilator time (hours)	63.7 ± 81.8	66.2 ± 87.2	106.3 ± 204.8	<0.001
intensive care unit stay (hours)	74.9 ± 75.6	69.4 ± 62.2	92.4 ± 135.1	<0.001
Hospital stay (days)	16.5 ± 13.0	17.8 ± 8.9	18.8 ± 20	<0.001
30-day mortality	4 (9.76)	4 (25.0)	6 (10.9)	0.260
Computed tomography angiography follow-up with patent false lumen	18 (51.4)	6 (50.0)	26 (59.1)	0.741

Data are presented as mean ± standard deviation or as numbers and percentages.

p < 0.05 was considered statistically significant.

Postoperative Data

Regarding postoperative results, the TAR group had the highest volume of mediastinal drainage at 24 hours, followed by the HAR and translocation groups. However, the TAR group also had a significantly higher number of postoperative acute kidney injury patients. The HAR group had the longest duration of mechanical ventilation, ICU stay, and hospital stay, which was statistically significant. However, there was no statistically significant difference in 30-day mortality among the three groups ([Table 2]).

Mortality

The TAR group had the highest overall mortality rate at 25%, followed by the HAR group at 20%, and the translocation group at 14.6%. The 5-year overall survival rates for the translocation, TAR, and HAR groups were 81.9%, 75.0%, and 77.7%, respectively. The 5-year survival rates from aortic-related death for the translocation, TAR, and HAR groups were 86.4%, 86.5%, and 86.5%, respectively. The Kaplan–Meier curves and hazard ratios (HRs) showed no significant difference in overall mortality or aortic-related death among the three groups ([Table 3] and [Fig. 2]).

Fig. 2 Kaplan–Meier curves for survival from overall death and aortic-related death. (A) Overall survival. (B) Survival free of aortic-related death. p < 0.05 was considered statistically significant. HAR, hemiarch replacement; TAR, total arch replacement; Translocation, hemiarch replacement with innominate artery translocation.

Table 3 Hazard ratio (HR)

Variables	HR	p-Value	95% Confidence interval	Adjusted hazard ratio[a]	p-Value	95% Confidence interval
Overall deaths:
Translocation	0.78	0.632	0.28, 2.12	0.66	0.442	0.23, 1.89
total arch replacement (TAR)	1.39	0.573	0.44, 4.37	1.11	0.878	0.28, 4.51
hemiarch replacement (HAR)	Reference			Reference
Aortic-related death:
Translocation	1.01	0.987	0.28, 3.64	0.80	0.753	0.21, 3.14
TAR	1.31	0.745	0.26, 6.50	0.85	0.881	0.10, 6.92
HAR	Reference			Reference
Reintervention:
Translocation	3.46	0.003	1.51, 7.89	3.62	0.004	1.50, 8.74
TAR	5.48	0.003	1.79, 16.8	6.36	0.004	1.81, 22.3
HAR	Reference			Reference
Re-thoracic endovascular aortic repair:
hemiarch replacement with innominate artery translocation (Translocation)	6.64	0.001	2.16, 20.4	12.16	<0.001	3.14, 14.12
TAR	6.33	0.002	1.92, 20.9	10.66	0.002	2.34, 48.44
HAR	Reference			Reference
Re-TAR:
Translocation	1.45	0.643	0.30, 6.93	2.15	0.371	0.40, 11.5
TAR	–	–	–	–	–	–
HAR	Reference			Reference

Abbreviation: Translocation, hemiarch replacement with innominate artery translocation.

p < 0.05 was considered statistically significant.

^a Adjusted HR, analyzed by Cox regression and adjusted with sex, age, old cerebrovascular accident, cardiopulmonary bypass time, aortic clamp time, circulatory arrested time, and temperature.

Our study explored prognostic risk factors for all-cause mortality, which are listed in [Table 4]. Both univariable and multivariable analyses revealed that preoperative hypotension, malperfusion, and neurologic symptoms were statistically significant risk factors that increased mortality, while false lumen thrombosis at the aortic arch and descending aorta level were factors that reduced mortality.

Table 4 Risk factors for all-cause mortality

	Univariable			Multivariable
Variables	odds ratio	p-Value	95% Confidence interval	Odds ratio	p-Value	95% Confidence interval
Male	0.72	0.511	0.27, 1.89	–
Age >65 years	1.69	0.291	0.64, 4.46	–
Hypertension	2.47	0.402	0.29, 20.4	–
Dyslipidemia	2.05	0.173	0.73, 5.76	–
Diabetes mellitus type 2	2.02	0.207	0.67, 6.07	–
Smoking	1.12	0.851	0.34, 3.73	–
Chronic kidney disease	2.15	0.120	0.81, 5.67	–
Marfan's syndrome	0.71	0.756	0.08, 6.21	–
Malperfusion	5.91	0.001	2.12, 16.4	9.43	0.002	2.21, 40.3
Preoperative hypotension	4.05	0.010	1.39, 11.8	7.36	0.005	1.84, 29.5
Neurologic symptom	6.00	0.003	1.82, 19.7	5.28	0.038	1.09, 25.4
Aortic regurgitation	1.71	0.289	0.63, 4.64	–
Hemopericardium	2.24	0.126	0.79, 6.29	–
Entry tear site:
Zone 0	0.75	0.596	0.26, 2.18	–
Zone 1	2.44	0.181	0.66, 9.04	–
Zone 2	0.95	0.959	0.19, 4.80	–
Zone 3	1.46	0.746	0.14, 14.8	–
Arch branch dissection	2.85	0.114	0.78, 10.4	–
Femoral canulation	0.30	0.032	0.10, 0.91	0.47	0.386	0.09, 2.54
Axillary canulation	2.18	0.324	0.46, 10.3	–
Adventitia inversion for distal	1.50	0.426	0.55, 4.07	–
Operative time >6 hours	2.40	0.114	0.81, 7.11	–
Circulatory arrest >1 hour	0.30	0.259	0.04, 2.43	–
computed tomography angiography follow-up with false lumen thrombosis:
Arch level	0.08	0.001	0.02, 0.35	0.03	0.002	0.01, 0.28
Descending level	0.13	0.008	0.03, 0.58	0.06	0.011	0.01, 0.53

p < 0.05 was considered statistically significant.

Reintervention

The translocation group had a higher rate of reintervention at 41.5%, compared with 31.3% in the TAR group and 16.4% in the HAR group. The median time to reintervention was 4.72 years for the translocation group and 1.47 years for the HAR group. The Kaplan–Meier curves and HRs showed that both the translocation and TAR groups had a significantly increased risk of reintervention compared with the HAR group ([Table 3] and [Fig. 3]). Details on the indications for reintervention and the types of reintervention procedures performed are presented in [Table 5].

Table 5 Reintervention

Variables	Innominate translocation n = 41	Total arch replacement n = 16	Hemiarch replacement n = 55	p-Value
Reintervention	17 (41.5)	5 (31.3)	9 (16.4)	0.023
Re-thoracic endovascular aortic repair	15 (36.6)	5 (31.3)	4 (7.3)	0.001
Redo total arch replacement	2 (4.8)	0 (0)	5 (9.1)	0.725
Cause of reintervention:				0.105
Ruptured, impending, and conceal ruptured	1 (2.4)	0 (0)	1 (1.8)
Increase size of whole aorta (aneurysmal formation)	9 (22.0)	1 (6.3)	4 (7.3)
Rapid aortic growth	2 (4.9)	1 (6.3)	2 (3.6)
Radiologic risk factors[a]	5 (12.2)	3 (18.8)	2 (3.6)

Data are presented as numbers and percentages.

p < 0.05 was considered statistically significant.

^a From 2022 American Heart Association/American College of Cardiology (ACC/AHA) guidelines for aortic disease.

Fig. 3 Kaplan–Meier curves for reintervention. (A) Reintervention. (B) Re-thoracic endovascular aortic repair. (C) Re-total arch replacement. p < 0.05 was considered statistically significant. HAR, hemiarch replacement; Translocation, hemiarch replacement with innominate artery translocation.

Discussion

In our study of aortic dissection, it was found that the aggressive surgical technique resulted in a longer operative time and a higher risk of postoperative complications. Many studies recommend an aggressive approach to the aortic arch, using techniques such as total aortic repair (TAR), to maximize the resection of aortic pathology and entry tears and reduce residual patency of the false lumen.[12] [13] [14] However, it should be noted that the TAR technique may also lead to undesirable results.

In a study comparing outcomes between HAR and TAR, Rylski et al[2] found higher in-hospital mortality for the TAR group (29 vs. 22%). Interestingly, incomplete resection of the dissected aortic segment did not correlate with distal aortic reintervention. Another study by Lio et al[1] reported a mortality rate of approximately 33% for TAR, with a 5-year freedom from distal reintervention of 92.3%. In contrast, HAR was found to be a safer option, with a 5-year distal reintervention-free rate of 96.8%, according to both Lio et al[1] and Merkle et al.[4] Our study also found a higher overall mortality rate for TAR compared with HAR and translocation groups, with an all-cause mortality rate of 25%, consistent with other studies.[1] [2] [15] The complexity of TAR, with longer bypass time, aortic clamp time, and circulatory arrest time, increases the risk of postoperative complications and in-hospital mortality.

To identify risk factors for operative death in patients with ATAD, Kuang et al[16] conducted a preoperative risk assessment. They discovered that inotropic support, superior mesenteric artery malperfusion, and a large false lumen were significant risk factors for mortality. In a separate study, Conzelmann et al[17] found that organ malperfusion and longer operative time were significant risk factors for death. However, they found that operative technique and arch intervention did not have a significant impact on mortality. Similar to our study, preoperative malperfusion, hypotension, and neurological symptoms were found to be associated with an increased mortality rate on multivariable analysis. Moreover, the presence of false lumen thrombosis at the arch and/or descending level was associated with reduced mortality.

Although HAR has the lowest mortality rate, the rates of freedom from reinterventions after 10 years were between 70 and 74%, indicating that reintervention rates are still high with nonaggressive techniques.[18] [19]

Reintervention is often essential for life preservation when certain criteria are met, as the risk of aortic rupture or other complications increases with residual or progressive aortic pathology. According to the 2022 American Heart Association/American College of Cardiology (ACC/AHA) guidelines,[6] repeat open surgery is recommended when the residual aortic diameter in the ascending aorta or arch reaches ≥5.5 cm, or with rapid aortic growth (≥0.5 cm per year). Urgent reoperation may also be needed for symptoms like pain, rupture, or malperfusion syndrome. Patients with genetic conditions often require intervention at smaller sizes, around 5.0 cm. For the descending thoracic aorta, thoracic endovascular aortic repair (TEVAR) is recommended at 5.5 cm, or 5.0 cm for patients with connective tissue disorders, with rapid growth or complications such as endoleaks or stent failure also warranting reintervention.

Even in patients in their sixties or seventies, reintervention may be necessary if criteria are met or complications arise. Endovascular options like TEVAR can often offer a safer alternative to open surgery, but decisions should be individualized based on health, surgical risk, and postintervention quality of life.

According to Dohle et al,[20] reintervention procedures after previous HAR include redo open repair by TAR with an elephant trunk or FET, endovascular procedure by TEVAR, or false lumen closure with a candy plug device. The application of endovascular procedures was higher than that of reopening surgery.

The innominate translocation technique prepares for an easier second operation or reintervention since the first operation creates a proximal landing zone for future endovascular stent therapy. If patients undergo only HAR, the next endovascular surgery cannot complete a full treatment, as the proximal landing stent must spare the innominate artery origin. The native aorta, which tends to have some pathological change, still remains. In contrast, the innominate translocation and TAR techniques land the proximal portion of a stent graft in the prosthetic graft itself. Results show that the innominate translocation technique does require a longer operative time than HAR. All bypass times, aortic clamp times, and circulatory arrest times were shorter than TAR.

Although there was no statistically significant difference, our results showed that the mortality rate of innominate translocation was lower than TAR. The HR indicates that all-cause mortality and aortic-related mortality were not different between the three groups, indicating that the innominate translocation technique was not harmful, despite its more complete resection and preparation for future endovascular therapy.

In the innominate translocation group, 88.2% of reinterventions were endovascular, while 11.8% required open surgical intervention. Two cases involved a large pseudoaneurysm at the HAR anastomosis site, and an unfavorable landing zone limited the feasibility of endovascular repair. In the TAR group, all reinterventions (100%) were endovascular, with no open surgical procedures performed. For the HAR group, 44.4% of reinterventions were endovascular, while 55.6% were open surgical.

The higher reintervention rate observed in both the innominate translocation and TAR groups is likely due to the design of these techniques, which facilitate future endovascular procedures. Both techniques involve a more comprehensive repair, creating favorable proximal landing zones for safer and easier reinterventions. The translocation technique, in particular, was planned with reintervention in mind, showing a statistically significant increase in reintervention rates compared with other methods. In contrast, HAR, which does not involve the entire arch, often leaves more complex anatomy for future procedures, limiting the applicability and frequency of endovascular repairs. Thus, the higher reintervention rate in TAR and translocation groups likely reflects the advantages these techniques offer for facilitating future safe endovascular repairs, while HAR presents fewer endovascular options.

Reintervention after ATAD will be necessary for optimizing long-term results, as a residual dissection can degenerate into an aneurysm. Enlargement of the aneurysm increases the risk of rupture, as found by Rylski et al.[21] Endovascular intervention for descending aortic pathologies after DeBakey type I or II dissection surgical repair is associated with lower in-hospital mortality and better survival and does not raise the likelihood of later reinterventions.[21] The endovascular strategy after innominate artery translocation with HAR involves the neck vessel bypass with the right common carotid artery to left common carotid artery bypass and left common carotid artery to left subclavian artery bypass. After that, the endovascular stent lands on zone 0, just distal to the translocated innominate artery.

According to our study, the most common reason for reintervention in both the HAR and translocation groups was aneurysmal degeneration in the remaining dissected aortic section. For high-risk individuals in the TAR group, the most frequent cause of reintervention was radiological risk factors, as outlined in the same guideline.

Another important issue in the study results is the higher stroke rate observed in the Innominate translocation group (21.9%) compared with the TAR (12.5%) and HAR (12.7%) groups, which may be due to several factors. Innominate translocation involves more complex surgical techniques, increasing the manipulation of the aortic arch and raising the risk of embolic events, which could lead to a higher incidence of stroke. The approach used in this technique might also impact the stability of the aortic arch and cerebral perfusion, contributing to stroke risk. Additionally, the technical challenges of more extensive dissection or reconfiguration may raise the likelihood of debris dislodgement or thrombus formation. Patient factors, such as underlying vascular disease or comorbidities, might also predispose those in the translocation group to a higher stroke risk. Although the p-value of 0.436 indicates that the difference is not statistically significant, the higher rate in the innominate translocation group warrants further investigation to improve outcomes and refine techniques.

This study has some limitations, as it is a retrospective analysis of prospectively collected registry data from a single center. The study power was limited due to a relatively small patient cohort. The nonrandomized design, as well as the complexity and variability of the pathophysiology and morphology of ATAD, may also have influenced the results. Additionally, the surgical techniques used were based on the surgeon's preferences rather than the characteristics of the disease or indication. It is possible that some surgeons may have preferred to perform HAR in ATAD cases without considering the site of entry tear. Finally, this study did not report on the postoperative aortic diameters of the true lumen and residual false lumen during follow-up.

Conclusion

TAR had the highest postoperative overall mortality rate, followed by HAR with innominate translocation and HAR alone. However, there were no significant differences in overall mortality and aortic-related death between the three groups. Preoperative hypotension, malperfusion, and neurologic symptoms were significant risk factors for all-cause mortality, while false lumen thrombosis at the aortic arch and descending aorta level reduced mortality. Despite the innominate translocation technique having a higher reintervention rate, it had similar mortality outcomes to HAR and TAR. Thus, it could be a more convenient option for reintervention, including creating a proximal landing zone, which could benefit patients needing endovascular repair.

Conflict of Interest

None declared.

Acknowledgment

We would like to express our gratitude to the Chiang Mai University English Language Team (CELT) for their assistance in editing the language of this document.

Data Availability Statement

All data are publicly available. Data supporting the conclusions are included in the submission and/or accessed via https://doi.org/10.6084/m9.figshare.22331575.v1.

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Publication History

Received: 05 July 2023

Accepted: 10 October 2024

Article published online:
26 November 2024