Early-term and midterm outcomes of endovascular completion of high-risk subacute and early chronic residual dissection after type A repair

Abstract

Objectives

Late mortality, progressive aneurysmal degeneration, and major reinterventions remain frequent after repair of type A aortic dissection. This study aimed to evaluate early- and midterm outcomes of endovascular completion in patients with high-risk residual dissection treated during the subacute or early chronic phase.

Methods

This study was a single-center retrospective analysis of a prospectively maintained institutional database. All consecutive patients undergoing endovascular completion for high-risk residual aortic dissection after type A dissection repair between January 2017 and September 2025 were included. Completion was performed using thoracic endovascular aortic repair alone or combined with the stented-assisted balloon-induced intimal disruption and relamination technique when distal extension exceeded Ishimaru zone 5. Primary outcomes were 30-day mortality and morbidity, as well as 3- and 5-year survival and reintervention rates.

Results

Among 127 patients surviving initial type A repair, 48 (37.8%) underwent endovascular completion (subacute n = 33; early chronic n = 15). No 30-day deaths occurred, and technical success was achieved in all cases. Major adverse events occurred in 6.2%, with no spinal cord ischemia. Five patients (10.4%) required early reintervention. Median clinical follow-up was 54 months. Estimated survival was 97.9% at 3 years and 90.3% at 5 years. Freedom from major reintervention was 93.5% at 3 years and 89.1% at 5 years. False lumen thrombosis was achieved in 89.6% of thoracic and 81.4% of visceral segments.

Conclusions

Endovascular completion of high-risk residual dissection after type A repair is safe and effective, providing excellent midterm survival, low major reintervention rates, and high rates of aortic remodeling.

Three-dimensional (3D) reconstruction and axial plane views of a computed tomography angiography (CTA) comparing before (left) and after (right) endovascular completion treatment with TEVAR and STABILISE of a residual type A aortic dissection extending beyond Ishimaru zone 5. TEVAR, Thoracic endovascular aortic repair; STABILISE, stent-assisted balloon-induced intimal disruption and relamination.

Central Message.

Endovascular completion of high-risk residual dissection after type A repair is safe and effective, providing low major reintervention rates and high rates of aortic remodeling.

Perspective.

Aortic degeneration and late interventions remain a challenge after type A dissection aortic repair. This study aimed to evaluate early- and midterm clinical and radiologic outcomes after endovascular completion of residual aortic dissection in 48 patients. Endovascular completion commanded high survival rates, low major reintervention rates, and high rates of false lumen thrombosis.

See Commentary on page XXX.

Despite advances in surgical techniques, long-term outcomes after repair of acute type A aortic dissection (TAAD) remain suboptimal. Late mortality, progressive aneurysmal degeneration of the residual dissected aorta, and the need for major reinterventions continue to represent significant clinical challenges.^1,2 Several studies have shown that a substantial proportion of patients surviving the acute phase of TAAD develop distal aortic enlargement over time and frequently require complex secondary procedures, which are associated with considerable morbidity and mortality.^3,4

To mitigate these risks, more extensive surgical strategies involving aggressive treatment of the aortic arch during the acute phase have been adopted that aim to reduce the need for late arch reinterventions and to promote favorable remodeling of the thoracic aorta.⁵ Moreover, endovascular completion strategies using thoracic endovascular aortic repair (TEVAR) have been proposed for selected patients with residual dissection and high-risk features.⁶ However, similar to what has been observed in primary type B aortic dissection, the effect of isolated TEVAR is often limited to the covered aortic segment and does not completely prevent distal aortic growth because of the persistence of distal communications between the true and false lumen.

To date, limited evidence exists regarding strategies aimed at treating the entire residual dissected aorta after type A dissection repair and their impact on global aortic remodeling. Techniques designed to address the entire dissected aorta, such as stent-assisted balloon-induced intimal disruption and relamination (STABILISE), may offer a more comprehensive therapeutic approach by promoting extensive false lumen obliteration and favorable aortic remodeling. However, the safety, feasibility, and remodeling effects of such a whole-aorta strategy after type A dissection repair remain insufficiently characterized. Accordingly, the present study reports our experience with endovascular completion treatment of high-risk residual aortic dissection using TEVAR alone or in combination with the STABILISE technique, with a focus on early safety, midterm outcomes, and aortic remodeling.

Methods

Study Design

This was a single-center retrospective analysis of a prospectively maintained institutional database. All consecutive patients with subacute (14-90 days) or early chronic (91-365 days) residual aortic dissection who underwent endovascular completion treatment at our center between January 2017 and September 2025 were included.

The study was approved by the local ethics committee (protocol no. 0024559, June 3, 2020). Written informed consent to take part in the study and to publish the article has been obtained from all participants or their legal representatives. The privacy rights of participants have been observed. Inclusion criteria were as follows:

• •Residual aortic dissection after cardiac surgery for type I or retrograde type III dissection. Patients with type II dissection were excluded, as the lesion is confined to the ascending aorta.
• •Completion treatment performed during the subacute or early chronic phase. Patients treated during the acute or late chronic phase were excluded.
• •
  The presence of high-risk clinical or radiologic features:

  • ○
    Total descending aortic diameter ≥40 mm, or aortic enlargement ≥5 mm within 6 months
  • ○
    False lumen diameter ≥22 mm
  • ○
    Large entry tear located on the inner curvature, within 2 cm of the origin of the left subclavian artery (LSA) or near the distal surgical anastomosis
  • ○
    Residual intramural hematoma with ulcer-like projections showing rapid growth
  • ○
    Radiologic signs of malperfusion
  • ○
    Uncontrollable hypertension
  • ○
    Persistent pain
• •Absence of severe comorbidities after primary cardiac surgery. Patients with debilitating stroke, limb paralysis, or severe heart failure were excluded.
• •Life expectancy greater than 5 years and age <75 year old.

The indication for treatment was established after a multidisciplinary discussion within our aortic team, which comprised vascular surgeons, cardiac surgeons, and anesthesiologists. Completion treatment was offered to all patients who met the inclusion criteria and had at least one high-risk clinical or radiologic feature.

Operative Technique

Previous cardiac surgery

The surgical strategy for TAAD was oriented toward ascending aorta and aortic arch replacement with distal anastomosis in zone 2 and debranching of brachiocephalic trunk (BT) and left common carotid artery (LCCA). During circulatory arrest, open distal anastomosis was performed with antegrade cerebral perfusion maintained via the right subclavian artery and via selective cannulation of the LCCA and the LSA (Kazui technique). Once completed, visceral perfusion was restored via the dedicated accessory branch. After careful inspection, root replacement with valve-sparing techniques or aortic valve replacement was performed. After deairing the heart, coronary circulation was restored, and rewarming was started. Then, the first 2 branches of the graft were anastomosed to the BT and the LCCA, respectively. The LSA was left in situ distal to the anastomosis.

In patients presenting with reduced life expectancy or severe clinical compromise at hospital admission, a limited surgical repair consisting of ascending aorta replacement with or without hemiarch reconstruction was favored. Conversely, in cases with extensive entry tears involving the distal arch or retrograde type B dissections, more extensive strategies were adopted, including frozen or classic elephant trunk or total supra-aortic trunk debranching.

Endovascular completion

All procedures were performed in an operating room equipped with a portable C-arm, with the patient under general anesthesia, and with prophylactic cerebrospinal fluid drainage. TEVAR alone was performed when the dissection involved the aorta up to Ishimaru zone 5. The STABILISE technique, combining proximal TEVAR, distal bare-metal stent (BMS) deployment, and serial balloon dilatation, was used in patients with dissection extending below zone 5.

The proximal stent graft was sized according to both the diameter of the proximal surgical graft and the total aortic diameter, with a maximum oversizing of 10%. The presence of ascending aorta prosthetic kinking was carefully addressed to identify the best landing zone. When a more proximal landing zone was required, surgical, hybrid or total endovascular supra-aortic trunk revascularization was performed according to the patient's specific anatomy and type of previous cardiac surgery. TEVAR was extended distally to zone 5.

In patients treated with STABILISE, combinations of Zenith dissection endovascular stents (Cook Medical) were deployed from the thoracic to the infrarenal aorta. Under transesophageal echocardiographic guidance, serial balloon dilatations were performed to reappose the intimal flap to the aortic wall using a semicompliant Coda balloon (Cook Medical), inflated to a maximum diameter of 20 to 40 mm. Visceral vessel stenting was performed in cases of malperfusion and/or significant stenosis or occlusion.

In cases of distal stent-induced new entry tear (SINE) or reentry tears located in zones 9 and 10 with retrograde false lumen reperfusion, infrarenal aortic aneurysm, or iliac ectasia or occlusion, distal extended endovascular aortic repair (DEEVAR) was considered. DEEVAR procedures were staged in patients at high risk for spinal cord ischemia or when the first postoperative computed tomography (CT) did not show satisfactory infrarenal results. The DEEVAR technique was described in a previous report.⁷

Data Collection

Thirty-day outcomes were recorded for all patients. Complications were defined according to the reporting standards of Lombardi and colleagues.⁸ Technical success was defined as correct device deployment without type I or III endoleak and absence of intraoperative open surgical conversion or dissection-related death.

Clinical follow-up was based on outpatient visits and telephone interviews. Thoracoabdominal triple-phase CT was performed postoperatively, at 6 months, and at 1, 3, and 5 years. Maximum aortic diameters were measured at thoracic, visceral, infrarenal, and iliac levels using multiplanar reconstructions. False lumen status was defined according to Lombardi and colleagues⁸ and assessed separately at thoracic, visceral, and infrarenal segments. Perfused false lumen volume was measured semiautomatically, according to a previously described technique.⁹

Outcomes

Primary outcomes were 30-day mortality and morbidity, as well as 3- and 5-year mortality and reintervention rates. Reinterventions consisting exclusively of selective stenting or endovascular recanalization of aortic branches and false lumen embolization were classified as minor, whereas all remaining reinterventions involving treatment of the aorta were classified as major. Secondary outcome was aortic remodeling.

Statistical Analysis

Statistical analysis was performed using R software, version 4.2.2 (R Foundation for Statistical Computing). Continuous variables are presented as mean ± SD, and categorical variables as counts and percentages. Continuous variables are presented as mean ± SD when normally distributed, and median with IQR was used to present data that were not normally distributed. Comparisons were performed using the χ² or Fisher exact test for categorical variables and analysis of variance for continuous variables. Survival and freedom-from-event analyses were performed using Kaplan-Meier estimates. The log-rank test was used to assess differences in survival and freedom from reintervention. Multivariable analysis using Cox proportional hazards and logistic regression models was performed to identify factors associated with reintervention, aortic growth, and aortic remodeling.

Results

Between January 2017 and September 2025, a total of 152 patients were treated for TAAD at our institution. Of the 127 patients who survived, 48 (37.8%) underwent endovascular repair of the residual dissection during the subacute (n = 33) or early chronic (n = 15) phase. There were no missing data for any variable.

Patient and Dissection Characteristics

Baseline patient characteristics and dissection morphology are reported in Table 1.

Table 1.

Baseline characteristics of patients with residual dissection after type A repair

Variable	All (n = 48)	Subacute (n = 33)	Early chronic (n = 15)	P value
Patient characteristics
Male	40 (83.3)	27 (81.8)	13 (86.7)	1
Age, y	62.7 ± 9.8	61.1 ± 9.2	66.3 ± 10.0	.045
Hypertension	34 (70.8)	20 (60.6)	14 (93.3)	.037
Smoking	23 (47.9)	18 (54.5)	5 (33.3)	.29
Diabetes	2 (4.2)	2 (6.1)	0 (0)	1
Dyslipidemia	8 (16.7)	5 (15.1)	3 (20.0)	.69
Chronic obstructive pulmonary disease	7 (14.6)	7 (21.2)	0 (0)	.082
Coronary artery disease	2 (4.2)	2 (6.1)	0 (0)	1
Previous PTCA/CABG	1 (2.1)	1 (3.0)	0 (0)	1
Bicuspid valve	5 (10.4)	5 (15.1)	0 (0)	.16
Cocaine abuse	3 (6.2)	3 (9.1)	0 (0)	.54
Aberrant right subclavian artery	1 (2.1)	1 (3.0)	0 (0)	1
Previous surgery for type A dissection
Asc + hemiarch	3 (6.2)	2 (6.1)	1 (6.7)	1
AVR + Asc + hemiarch	2 (4.2)	2 (6.1)	0 (0)	1
Asc + hemiarch + BT and LCA reimplantation	28 (58.3)	19 (57.6)	9 (60.0)	1
AVR + Asc + hemiarch + BT and LCA reimplantation	3 (6.2)	3 (9.1)	0 (0)	.54
Asc + arch + total SAT reimplantation	2 (4.2)	1 (3.0)	1 (6.7)	.53
AVR + asc + arch + total SAT reimplantation	2 (4.2)	1 (3.0)	1 (6.7)	.53
Frozen/classic elephant trunk	6 (12.5)	4 (12.1)	2 (13.3)	1
Asc + hemiarch + RCA and LCA reimplantation (ARSA)	1 (2.1)	1 (3.0)	0 (0)	1
Asc + AMDS stent	1 (2.1)	0 (0)	1 (6.7)	.31
TAAD symptoms
Chest/back pain	47 (97.9)	33 (100)	14 (93.3)	.31
Altered consciousness/syncope	3 (6.2)	3 (9.1)	0 (0)	.54
Lower-limb ischemia	5 (10.4)	4 (12.1)	1 (6.7)	1
Acute renal failure	1 (2.1)	1 (3.0)	0 (0)	1
Bowel ischemia	2 (4.1)	1 (3.0)	1 (6.7)	.53
SCI	1 (2.1)	0 (0)	1 (6.7)	.31
Cerebrovascular accident/stroke	6 (12.5)	4 (12.1)	2 (13.3)	1
AMI/congestive heart failure	8 (16.7)	5 (15.1)	3 (20.0)	.69
Additional procedures	5 (10.4)	2 (6.1)	3 (20.0)	.30
Splenectomy + cholecystectomy	1	1	0
Pericardial drainage	1	1	0
BMS deployment + SMA stenting	1	0	1
Carotid-carotid bypass + right carotid-axillary bypass + BCT-RCA stenting	1	0	1
RCA graft + proximal RCA stenting	1	0	1
Residual dissection characteristics
Site of most proximal extension				.69
Arch/LSA	39 (81.2)	26 (78.8)	13 (86.7)
Descending thoracic aorta	9 (18.8)	7 (21.2)	2 (13.3)
Site of most distal extension				.031
Thoracic aorta	5 (10.4)	1 (3.0)	4 (26.7)
Abdominal aorta	9 (18.8)	5 (15.1)	4 (26.7)
Iliac arteries	31 (64.6)	24 (72.7)	7 (46.7)
Femoral arteries	3 (6.2)	3 (9.1)	0 (0)
Mean number of visible secondary entry tear	4.2 ± 2.2	4.7 ± 2.1	3.3 ± 2.2	.019
Diameter, mm
Thoracic	37.1 ± 4.3	36.4 ± 4.4	38.6 ± 3.4	.048
Visceral	26.9 ± 3.3	27.4 ± 2.9	26.0 ± 3.8	.10
Infrarenal	22.2 ± 3.5	22.4 ± 3.8	21.9 ± 2.5	.33
Diameter >40 mm	21 (43.7)	12 (36.4)	9 (60.0)	.12
FL status
Thoracic (n = 48)				.20
Patent	26 (54.2)	20 (60.6)	6 (40.0)
Partial thrombosis	19 (39.6)	12 (36.4)	7 (46.7)
IMH with ULPs	3 (6.2)	1 (3.0)	2 (13.3)
Visceral (n = 43)				.15
Patent	40 (93.0)	31 (96.9)	9 (81.8)
Partial thrombosis	3 (7.0)	1 (3.1)	2 (18.2)
Infrarenal (n = 40)				.25
Patent	39 (97.5)	30 (100)	9 (90.0)
Partial thrombosis	1 (2.5)	0 (0)	1 (10.0)

Statistically significant P values were reported in bold.

PTCA, Percutaneous transluminal coronary angioplasty; CABG, coronary artery bypass grafting; Asc, ascending; AVR, aortic valve replacement; BT, brachiocephalic trunk; LCA, left carotid artery; SAT, supra-aortic trunk; RCA, right carotid artery; ARSA, aberrant right subclavian artery; AMDS, Ascyrus Medical Dissection Stent; TAAD, acute type A aortic dissection; SCI, spinal cord ischemia; AMI, acute myocardial infarction; BMS, bare metal stent; SMA, superior mesenteric artery; LSA, left subclavian artery; FL, false lumen; IMH, intramural hematoma; ULP, ulcer-like projection.

Previous Cardiac Surgery

Types of previous cardiac surgery for acute type A aortic dissection are summarized in Table 1. The most common procedure was replacement of the ascending aorta and hemiarch with zone 2 anastomosis and reimplantation of BT and LCCA, which was performed in 64.5% of the patients. More extensive arch replacement with total supra-aortic trunk reimplantation was carried out in 8.4% of cases. Frozen or classic elephant trunk procedures were performed in 12.5% of patients. Limited repairs accounted for a small proportion of cases (10.5%). One patient was treated with the AMDS hybrid prosthesis (Artivion).

Indications for Endovascular Completion

Indications are summarized in Table 2. The most frequent indications were false lumen diameter >22 mm (47.9%) and thoracic aortic diameter >40 mm (43.7%). Thirteen patients presented with more than 1 high-risk characteristic (27.1%).

Table 2.

Procedural details of the endovascular completion of residual dissection after type A repair

Variable	All (n = 48)	Subacute (n = 33)	Early chronic (n = 15)	P value
Indications
Large distal anastomotic ET	6 (12.5)	5 (15.1)	1 (6.7)	.65
Diameter >40 mm	21 (43.7)	13 (39.4)	8 (53.3)	.37
False lumen >22 mm	23 (47.9)	15 (24.2)	8 (53.3)	.61
Persistent chest pain	4 (8.3)	3 (9.1)	1 (6.7)	1
Radiographic only malperfusion (renal)	3 (6.2)	3 (9.1)	0 (0)	.54
ULPs with rapid growth	3 (6.2)	1 (3.0)	2 (13.3)	.22
Large Kommerell diverticulum	1 (2.1)	1 (3.0)	0 (0)	1
Proximal landing zone (Hishimaru)				.62
0	2 (4.2)	2 (6.1)	0 (0)
2	33 (68.7)	23 (69.7)	10 (66.7)
3	8 (16.7)	4 (12.1)	4 (26.7)
4	5 (10.4)	4 (12.1)	1 (6.7)
Intervention				.028
STABILISE	43 (89.6)	32 (97.0)	11 (73.3)
TEVAR	5 (10.4)	1 (3.0)	4 (26.7)
Timing				.65
One-stage	42 (87.5)	28 (84.8)	14 (93.3)
Staged	6 (12.5)	5 (15.1)	1 (6.7)
1° TEVAR + 2° STABILISE	1 (2.1)	1 (3.0)	0 (0)
1° STABILISE + 2° DEEVAR	5 (10.4)	4 (12.1)	1 (6.7)
Type of endograft				.23
Off-the-shelf	40 (83.3)	29 (87.9)	11 (73.3)
Custom-made device	8 (16.7)	4 (12.1)	4 (26.7)
Supra-aortic trunk revascularization	35 (72.9)	25 (75.7)	10 (66.7)	.51
Carotid-subclavian or carotid-axillary bypass	22 (45.8)	17 (51.5)	5 (33.3)
Zone 0 intrathoracic BT and LCA debranching + left carotid-subclavian bypass	1 (2.1)	1 (3.0)	0 (0)
Carotid-subclavian bypass + double zone 0 chimney (ARSA)	1 (2.1)	1 (3.0)	0 (0)
LSA chimney	2 (4.2)	2 (6.1)	0 (0)
LSA branch	7 (14.6)	3 (9.1)	4 (26.7)
LSA fenestration + bridging stent	2 (4.2)	1 (3.0)	1 (6.7)
DEEVAR	19 (39.6)	17 (51.5)	2 (13.3)	.024
Bifurcated device	17 (35.4)	15 (45.4)	2 (13.3)
CERAB	2 (4.2)	2 (6.1)	0 (0)
Adjunctive procedures	13 (27.1)	9 (27.3)	4 (26.7)	1
LSA stenting	2 (15.4)	1 (3.0)	1 (6.7)
Right renal stenting	2 (15.4)	2 (6.1)	0 (0)
Left renal artery stenting	10 (76.9)	7 (21.2)	3 (20.0)
Iliac stenting	2 (15.4)	2 (6.1)	0 (0)

Statistically significant P values were reported in bold.

ET, Entry tear; ULP, ulcer-like projection; STABILISE, stent-assisted balloon-induced intimal disruption and relamination; TEVAR, thoracic endovascular repair; DEEVAR, distal extended endovascular repair; BT, brachiocephalic trunk; LCA, left carotid artery; ARSA, aberrant right subclavian artery; LSA, left subclavian artery; CERAB, covered endovascular reconstruction of aortic bifurcation.

Types of Interventions

Procedural details are listed in Table 2. The majority of patients underwent the STABILISE technique (89.6%). TEVAR alone was performed in 10.4% of cases, more frequently in the early chronic subgroup. Most procedures were completed in a single stage (87.5%).

Endografts were predominantly off-the-shelf devices (83.3%), although custom-made grafts were used in 16.7%. Supra-aortic trunk revascularization was necessary in 72.9% of patients, most commonly for the LSA. Different approaches were used: carotid-subclavian or carotid-axillary bypass in 45.8% of cases, branched or fenestrated stent-grafts in 14.6%, fenestrations with bridging stents in 4.2%, and chimney configurations in 4.2%. In isolated cases, more complex debranching of the brachiocephalic trunk and left carotid artery was performed.

DEEVAR was performed in 39.6% of patients, with bifurcated devices most frequently used. Two patients underwent covered endovascular reconstruction of aortic bifurcation configurations. Adjunctive procedures included renal and iliac stenting in approximately one quarter of cases.

Thirty-Day Outcomes

At 30 days, no deaths occurred, and technical success was achieved in all patients. Major adverse cardiovascular events were observed in 3 patients (6.2%), including 2 cerebrovascular and 1 cardiac complication. Pulmonary events occurred in 3 cases (6.2%), and 3 patients developed acute kidney injury (6.2%). No spinal cord or bowel ischemia were observed.

Five patients (10.4%) required early reintervention. Three were due to acute complications: 2 for iatrogenic rupture of the infrarenal aorta and iliac artery, respectively, and 1 for infection of a bypass graft. Two additional reinterventions were prompted by suboptimal early CT findings, showing persistence of false lumen perfusion despite initial treatment.

Midterm Outcomes

Median clinical follow-up was 54 ± 25 months, with radiologic follow-up available for 35 ± 21 months.

Survival

Kaplan-Meier estimated overall survival was 97.9% at 36 months (95% CI, 94.0-100) and 90.3% at 60 months (95% CI, 80.1-100) (Figure 1). Beyond 72 months, survival decreased to 72.9% at 84 months (95% CI, 52.5-100). One aortic-related death occurred during follow-up. The patient was a drug user who developed endocarditis 1 month after STABILISE and died of subsequent aortic infection.

Figure 1.

Cumulative Kaplan-Meier estimate of patient survival over 6 years (95% CI).

Reinterventions

Freedom from all reinterventions was 86.6% at 36 months (95% CI, 77.1-97.3) and 82.3% at 60 months (95% CI, 70.6-95.9) (Figure 2). Freedom from major reinterventions was 93.5% at 36 months (95% CI, 86.7-100) and 89.1% at 60 months (95% CI, 78.8-100). No differences between subacute and early chronic group were found. Complete thoracic and visceral remodeling at first follow-up was the only factor associated with reintervention risk, showing a protective effect (hazard ratio, 0.07; 95% CI, 0.0089-0.669, P = .02).

Figure 2.

Cumulative Kaplan-Meier estimate of patient freedom from all reinterventions (blue) and from major reinterventions (green) over 6 years (95% CI).

Reinterventions are listed in Table 3. During follow-up, 2 patients required redo cardiac surgery: one for a type Ia endoleak after prior LSA embolization, and another for a noncoronary sinus pseudoaneurysm later complicated by type Ia endoleak treated with proximal TEVAR. Another patient also underwent proximal TEVAR for type Ia endoleak. One patient required completion DEEVAR with left renal stenting, and another underwent 2 procedures for progressive aortic enlargement with persistent false lumen perfusion, which included distal TEVAR, DEEVAR, and hypogastric occlusion. Two minor reinterventions were performed for subclavian branch occlusion and persistent thoraco-visceral false lumen perfusion.

Table 3.

Indications for midterm reinterventions and type of procedure per patient

	Reintervention type	Time, mo	Indications
1	TEVAR zone 1 (relining with uncovered stent)	4	Endoleak Ia
2	Ascending/arch replacement + BT/LCA reimplantation TEVAR zone 2 + LRA stenting + LEIA stenting	6 7	Valsalva sinus pseudoaneurysm Endoleak Ia + FL perfusion (LRA – LEIA)
3	Celiac trunk stenting∗	6	CT origin entry tear with FL perfusion
4	DEEVAR + LRA stenting + FL embolization	9	Residual FL perfusion (LRA – LCIA) + iliac enlargement
5	LSA branch endovascular recanalization∗	10	Symptomatic branch occlusion
6	TEVAR zone 5 + DEEVAR + internal iliac embolization Internal iliac ligature + TEVAR zone 5 + RRA stent	14 22	SINE with residual FL perfusion + aortic enlargement Persistent residual FL perfusion
7	LSA embolization∗ Ascending and hemiarch replacement with BT and LCA reimplantation	31 79	FL perfusion (LSA) + aortic enlargement Endoleak Ia with aortic arch enlargement

TEVAR, Thoracic endovascular aortic repair; BT, brachiocephalic trunk; LCA, left carotid artery; LRA, left renal artery; LEIA, left external iliac artery; FL, false lumen; DEEVAR, distal extended endovascular aortic repair; LCIA, left common iliac artery; LSA, left subclavian artery; SINE, stent-induced new entry tear; RRA, right renal artery.

^∗Minor reintervention.

Aortic Remodeling

Radiologic outcomes are shown in Table 4. Complete false lumen thrombosis or cicatrization was documented in 89.6% of thoracic, 81.4% of visceral, and 60% of infrarenal segments. Complete remodeling of both thoracic and visceral segment was documented in 81.2% of patients.

Table 4.

Thirty-day and midterm results of the endovascular completion of residual dissection after type A repair

Variable	All (n = 48)	Subacute (n = 33)	Early chronic (n = 15)	P value
30-d results
Death	0 (0)	0 (0)	0 (0)	1
Technical success	48 (100)	33 (100)	15 (100)	1
Access complications (n = 108)	2 (1.8)	1 (1.3)	1 (3.1)	.49
Complications
Major adverse cardiovascular events	3 (6.2)	3 (9.1)	0 (0)	.54
Cerebrovascular	2 (4.2)	2 (6.1)	0 (0)	1
Cardiac	1 (2.1)	1 (3.0)	0 (0)	1
Pulmonary	3 (6.2)	2 (6.1)	1 (6.7)	1
Acute renal failure (AKIN >2)	3 (6.2)	1 (3.0)	2 (13.3)	.23
Bowel ischemia	0 (0)	0 (0)	0 (0)	1
SCI	0 (0)	0 (0)	0 (0)	1
Infrarenal aortic/iliac rupture	2 (4.2)	1 (3.0)	1 (6.7)	.53
Bypass infection	1 (2.1)	1 (3.0)	0 (0)	1
Reinterventions	5 (10.4)	4 (12.1)	1 (6.7)	1
Treatment of complications	3 (6.2)	2 (6.1)	1 (6.7)	1
Aorto-iliac graft	1	1	0
Iliac suture	1	0	1
Carotid-brachial bypass with GSV	1	1	0
Adjunctive procedure	2 (4.2)	2 (6.1)	0 (0)	1
LSA stenting	1	1 (3.0)	0
LSA embolization + celiac trunk stenting	1	1 (3.0)	0
Midterm clinical results (54 ± 25 mo)
Death	5 (10.4)	4 (12.1)	1 (6.7)	1
Aortic-related death	1 (2.1)	1 (3.0)	0 (0)	1
Late complications
Cerebrovascular events	2 (4.2)	2 (6.1)	0 (0)	1
Cardiac complications	2 (4.2)	2 (6.1)	0 (0)	1
Symptomatic LSA branch occlusion	1 (2.1)	0 (0)	1 (6.7)	.31
Reinterventions	6 (12.5)	4 (12.1)	2 (13.3)	1
Midterm radiologic results (35 ± 21 mo)
EL Ia	3 (6.2)	3 (9.1)	0 (0)	.54
Supraortic trunk/surgical debranching occlusion (n = 145)	2 (1.4)	1 (1.0)	1 (2.2)	.52
Visceral vessel occlusion (n = 171)	2 (1.2)	2 (1.6)	0 (0)	1
Diameter, mm
Thoracic	34.8 ± 6.1	33.9 ± 5.6	36.8 ± 6.7	.063
Visceral	28.5 ± 5.0	28.7 ± 4.3	28.0 ± 6.2	.32
Infrarenal	22.4 ± 4.3	22.6 ± 4.4	22.0 ± 3.9	.32
Growth >5 mm	5 (10.4)	2 (6.1)	3 (20.0)	.30
Thoracic	2 (4.1)	0 (0)	2 (13.3)	.093
Visceral	4 (8.3)	2 (6.1)	2 (13.3)	.57
Infrarenal	2 (4.1)	1 (3.0)	1 (6.7)	.53
Thoracic shrinkage >5 mm	16 (33.3)	11 (33.3)	5 (33.3)	1
Diameter >55 mm	0 (0)	0 (0)	0 (0)	1
FL status
Thoracic (n = 48)				.30
Patent	0 (0)	0 (0)	0 (0)
Partial thrombosis	5 (10.4)	2 (6.1)	3 (20.0)
Complete thrombosis/cicatrization	43 (89.6)	31 (93.9)	12 (80.0)
Visceral (n = 43)				.54
Patent	4 (9.3)	2 (6.2)	2 (18.2)
Partial thrombosis	4 (9.3)	3 (9.4)	1 (9.1)
Complete thrombosis/cicatrization	35 (81.4)	27 (84.4)	8 (72.7)
Infrarenal (n = 40)				.38
Patent	12 (30)	8 (26.7)	4 (40.0)
Partial thrombosis	5 (12.5)	3 (10.0)	2 (20.0)
Complete thrombosis/cicatrization	23 (60)	19 (63.3)	4 (40.0)
Perfused FL volume (mL)
Thoracic	26.9 ± 21.2	33.5 ± 23.1	18.0 ± 14.3	.21
Visceral	8.6 ± 6.7	8.2 ± 7.7	9.3 ± 4.0	.44
Aorto-iliac	12.4 ± 10.3	14 ± 11.3	7.5 ± 3.2	.12

AKIN, Acute Kidney Injury Network; SCI, spinal cord ischemia; GSV, great saphenous vein; LSA, left subclavian artery; EL, endoleak; FL, false lumen.

Thoracic aortic shrinkage >5 mm occurred in one third of patients. Aortic growth >5 mm was observed in 10.4% of patients. Of these, 3 presented with persistent false lumen perfusion, whereas 2 developed dilatation despite complete remodeling. No patient exceeded 55 mm of maximum diameter during follow-up. Mean perfused false lumen volume was 26.9 ± 21.2 mL, 8.6 ± 6.7 mL, and 12.4 ± 10.3 mL at the thoracic, visceral, and infrarenal level, respectively.

Complete thoracic and visceral remodeling at first follow-up predicted long-term complete remodeling (odds ratio, 3.47; 95% CI, 0.90-7.45, P = .028), whereas preoperative aortic diameter >40 mm and older age were associated with a reduced likelihood of complete remodeling (−3.10; 95% CI, −7.24 to −0.58, P = .048 and −0.22, 95% CI, −0.50 to −0.05, P = .043, respectively). No factors associated with long-term aortic growth were identified.

Discussion

Findings suggest that intentional treatment of the entire residual dissected aorta may represent a feasible strategy to promote global aortic remodeling after type A dissection repair. At 3-year follow-up, overall survival rate and freedom from reinterventions were high, demonstrating procedure safety. Complete aortic remodeling was achieved in the majority of patients. Results suggest that treatment strategies extending beyond proximal pathology to address the entire residual dissected aorta may improve remodeling trajectories after type A dissection repair.

After surgical repair of TAAD, long-term mortality remains substantial, with affected patients experiencing approximately a 2-fold greater risk of death compared with the age-matched general population.¹⁰ Several large series have reported 10-year mortality rates ranging from 30% to 50%, frequently driven by aortic-related causes.^1,2,10 The distal aorta, in particular, represents a major source of late adverse events following proximal repair, as progressive aneurysmal degeneration of the residual dissected segments is common.

A considerable proportion of patients therefore require complex, staged open redo-surgery, involving either the proximal aorta and the distal thoracic and thoracoabdominal aorta. Importantly, the type and operative risk of secondary interventions largely depend on the extent of the initial surgical repair. In patients who underwent limited surgery under a “survival-first” premise, secondary treatment frequently involves the aortic arch and proximal descending thoracic aorta, requiring strategies such as arch rerouting with TEVAR, frozen or classic elephant trunk, or conventional open repair through a posterolateral approach.¹¹ These secondary procedures are often technically demanding and associated with significant morbidity and mortality.³ Contemporary reports have documented operative mortality rates of 10% to 20% for redo surgery of the distal aortic arch after previous TAAD repair.^4,12,13 Despite the advent of novel endovascular arch devices, only a subset of this patients meet the anatomical requirements for their use; moreover, these procedures remain associated with a relatively high risk of stroke, and mid- to long-term outcomes are still largely unknown.¹⁴ Conversely, patients who undergo an extensive initial arch repair are more often suitable candidates for less complex total endovascular treatment of the distal arch and the thoracoabdominal aorta or hybrid approaches combining TEVAR with extrathoracic surgical debranching.¹¹

In the present study, nearly 90% of patients underwent an extensive initial surgical repair for TAAD. In particular, our institutional strategy favors zone 2 aortic arch replacement with proximal reimplantation of the BT and LCCA. As also reported by Hasami and colleagues⁶ and Desai and colleagues,¹⁵ the main advantage of this strategy compared with more limited approaches is the creation of a suitable prosthetic landing zone for subsequent endovascular completion, potentially avoiding the need for secondary aortic arch open surgery. Moreover, when compared with the frozen elephant trunk technique, this strategy is associated with shorter circulatory arrest times, a lower risk of recurrent laryngeal nerve injury, and a reduced incidence of spinal cord ischemia, as endovascular completion and LSA management are deferred to the subacute or early chronic phase.^2,16

Regardless of the initial strategy, the almost constant presence of distal entry tears or distal SINE results in persistent false lumen perfusion below the initial reconstruction. Distal reentry tears are increasingly recognized as playing a key role in maintaining residual false lumen perfusion and driving progressive aortic enlargement.^17,18 As with TEVAR for primary type B aortic dissection, isolated thoracic treatment results in aortic remodeling largely limited to the covered segment. Importantly, the morbidity and mortality associated with treatment of thoracoabdominal aneurysms remain substantial. Some authors reported operative mortality rates of approximately 5% to 10% for endovascular repair and 8% to 24% for open repair.19, 20, 21

To address this issue, since 2017 we have adopted an endovascular completion strategy in selected patients treated for TAAD who exhibit high-risk features. When the dissection extension is limited to Ishimaru zone 5, TEVAR alone is sufficient to treat the entire diseased aorta. Conversely, in cases with distal extension beyond zone 5, we routinely apply the STABILISE technique, which enables complete false lumen elimination by reapposing the dissection flap to the aortic wall. During the study period, approximately 40% of patients who survived the acute phase of TAAD underwent endovascular completion treatment.

The present study demonstrates high technical success rates and a favorable safety profile of this approach. No 30-day deaths occurred, and technical success was achieved in all cases. Major adverse events occurred in 6.2%, with no spinal cord ischemia. These findings are consistent with previously reported series.^9,22, 23, 24

Five-year survival in this cohort was high (90.3%) when compared with other reports describing midterm outcomes of patients who survived TAAD repair.^10,25,26 This favorable survival was observed in the context of high rates of complete aortic remodeling (81.2% in both the thoracic and visceral segment), low rates of aortic growth and low rate of major reintervention (10.9% at 5 years). Although follow-up is still limited and the study was not designed to demonstrate a difference in survival, these results support the hypothesis that the risks associated with routine completion treatment in patients with residual dissection and high-risk features might be offset by potential long-term benefits in terms of survival, aneurysmal degeneration, and major reintervention. However, this potential effect remains hypothetical and should be confirmed by comparative studies. Furthermore, it should be considered that achieving complete remodeling does not necessarily predict lifelong freedom from aneurysmal degeneration. In this study, 2 of the 5 patients who developed aortic growth had complete false lumen remodeling. During the study period, several technical refinements were introduced. First, the 46-mm BMS was abandoned in favor of the 36-mm device after some patients who received the former exhibited visceral aortic growth despite complete remodeling. Second, greater attention was paid to the overlap between stent graft and BMS during both preoperative planning and intraoperative molding to prevent SINE creation and persistent false lumen perfusion. Third, we progressively increased the use of branched devices for LSA revascularization instead of surgical debranching. Finally, DEEVAR indications were restricted to selected patients after 2 cases of in-hospital infrarenal and iliac rupture requiring open repair.

Statistical subgroup analysis comparing patients treated in the subacute and early chronic phases did not demonstrate significant differences. However, these findings should be interpreted cautiously, given the small patient population. In our experience, the dissection flap behaves similarly during STABILISE in both groups. This may support postponing endovascular completion in selected patients, allowing further clinical recovery and sufficient time for custom-made endograft planning and manufacture, thereby enabling a patient-specific, fully endovascular approach to the aortic arch.

Limitations

First, this is a retrospective study with a relatively small number of patients; therefore, the results should be validated in larger, prospective randomized studies, although such studies are difficult to conduct in this patient population. Second, there are currently no well-defined criteria to accurately identify patients with residual TAAD who are truly at high risk for adverse evolution. Most available data are extrapolated from studies on primary type B aortic dissection, which is known to have a different natural history. This represents an area that warrants further investigation to better define indications for intervention. Third, restricting the study to patients who survived surgical treatment for type A aortic dissection and met predefined inclusion criteria inevitably introduced selection bias, limiting comparisons with the existing literature. Finally, our results require further validation with longer follow-up. The time interval between 5 and 10 years after the initial repair is likely the most informative for comparing reintervention rates and mortality between patients undergoing endovascular completion and those managed conservatively.

Conclusions

Endovascular completion of high-risk residual dissection after type A repair is associated with favorable early and mid-term outcomes, including low rates of major reintervention and high rates of aortic remodeling. This strategy may potentially translate into improved long-term survival, although this remains a hypothesis that requires validation in larger cohorts with longer follow-up.

Ethics Declaration

Written informed consent to take part in the study and to publish the article has been obtained from all participants or their legal representatives. The privacy rights of participants have been observed.

This study was performed in compliance with relevant laws, regulatory frameworks and guidelines where the research took place. This study was approved by the Local Ethics Committee (Comitato etico Brianza). (Approval No. 0024559)

Conflict of Interest Statement

The authors reported no conflicts of interest.

The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.