Hybrid Arch Aneurysm Repair With Ascending Aortic Wrap and TEVAR

Introduction

Thoracic aorta aneurysms are not an uncommon pathology, they are found in 10.4 per 100 000 persons per year. ¹ Historically, aortic arch aneurysms requiring treatment has been managed by open surgical repair,^2,3 through a thoracotomy or a sternotomy. These repairs have shown worst outcome in high-risk patients, with higher mortality at 30 days and 1 year. ⁴

These high-risk patients can now be offered an endovascular arch repair (arch BEVAR) with supra-aortic trunk vessel (SAV) branches. There is a subset of patients who are not candidates for such repair, due to nonfavorable proximal seal zone (ascending aorta [AA] diameter >38mm or short proximal seal length <30mm).

We believe that for this subset of patients, the answer might be an ascending aorta wrap (AW) associated with endovascular repair of the arch. The wrap is created to optimize the proximal landing zone by reducing the diameter to less than 38mm, which is the largest diameter to obtain a proximal seal according to the instructions for use from thoracic endograft manufacturers. This technique does not require cardiopulmonary bypass (CPB) support, neither aortic cross-clamping.

Methods and Materials

Technique of AW and Surgical Debranching

This procedure is performed by a senior cardiothoracic surgeon. These cases are done off cardiac pump; however, potential cannulation sites are prepared, CPB lines are on the field and heparin available in case conversion to be on pump is required, as dissection of the posterior wall of the AA to separate it from the right pulmonary artery can be challenging. Continuous monitoring with an arterial line is mandatory. When the SAV are successively clamped, blood pressure is monitored from the femoral artery. After a median sternotomy, dissection of the SAV is performed. Under controlled hypotension with systolic blood pressure <75mmHg, the AA is dissected from the pulmonary trunk, right pulmonary artery and arch concavity until 3 fingers can be passed behind the AA. ⁷ The left atrium roof is dissected from the noncoronary sinus of the aorta. When debranching of the SAV is concomitantly performed (Figure 1), after injecting 50 units/kg of heparin, a lateral curved clamp is applied at the side or the front of the very proximal AA. An arteriotomy is performed, then an 8 or 10mm Dacron tube is anastomosed in a side to end fashion. The Dacron tube is clamped distally and passed behind the innominate vein. The systolic blood pressure is then increased to >140mmHg before anastomosing the SAV. First is the brachiocephalic artery (BCA), which is divided from the arch by a stapler device, then anastomosed to the Dacron tube in an end to side fashion. Next the left subclavian artery (LSA) anastomosis is performed in an end-to-end fashion. Last is the left common carotid artery (LCCA), anastomosed to the Dacron graft in an end to side fashion. The AA wrap is next performed, with a target maximum diameter of 38mm. The technique has been thoroughly described in a previous publication. ⁸ From a 15 × 15cm Teflon sheet (Bard Inc, Murray Hill, NJ), using the 2ΠR equation, we fashion a piece that is wrapped around the AA and sutured using a running mattress suture (3-0 prolene). The Teflon sheet is not tacked to the aorta. Another piece of Teflon is then cut to cover the aortic arch. If the wrap is performed with no debranching, the Teflon cut will be accommodating for the native SAV vessels to go through. If debranching of the SAV was performed, the stumps of the innominate and left common carotid arteries are covered by the proximal arch wrapping. Large hemostatic clips can be placed close to the proximal anastomosis of the Dacrcon prosthesis to help locate the origin of the debranching prosthesis under fluoroscopy during the TEVAR procedure.

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Figure 1.

Intra operative view (A) and anatomy sketch (B) of an ascending aorta and arch wrap with surgical debranching of the supra-aortic trunk vessels. The overlap between the wrapped ascending aorta and thoracic endograft is visualized on the postoperative CTA multiplanar reconstruction (C).

The TEVAR is performed in our hybrid room (Discovery, GE Healthcare) under fusion guidance. Similarly to a TAVR procedure, access to the left ventricle through the aortic valve is required to position a double curved Lunderquist (Cook Medical) wire at the apex. Endograft delivery is performed under rapid pacing. We aim at maximum overlap with the wrapped AA (10% oversizing). Distal sealing zone (>30mm, 20% oversizing) was obtained in nondiseased descending thoracic aorta. Two or 3 endografts were implanted in 8/12 patients, with large (>55mm) overlapping zones. In a subset of patients, the SAV debranching was performed with an endovascular approach with CMD arch BEVAR (2 or 3 branches with various designs, the most recent configuration consisting of an antegrade branch for the innominate artery and 2 retrograde branches for the left CCA and LSCA, Cook Medical) (Figure 2).

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Figure 2.

Changes in the aortic landing zone post-WA for the same patient.

Results

From 2013 to 2024, 12 patients were treated with AW and zone 0 TEVAR (Table 1). Nine patients presented with large arch aneurysms and underwent concomitant or staged AA wrap TEVAR (group A), and 3 patients presented with a dissecting arch aneurysm depicted during FU after AW for acute type A dissection (51.5 months on average between the wrap and the TEVAR) (group B).

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Table 1.

Patients Characteristics (n=12).

Variable	Value
Age, years	73 (61-84)
Male sex	6 (50%)
Boby mass index, kg/m2	30 (21-41)
Comorbidities
High blood pressure	11 (92%)
Ischemic cardiomyopathy	2 (17%)
Arrythmia	4 (33%)
Pulmonary embolism	2 (17%)
Diabetes melitus	1 (8%)
CKD	3 (25%)
COPD	1 (8%)
Tobacco use (active or historic)	2 (17%)
Aortic history
Dissecting arch aneurysm	7 (58%)
Atherosclerotic arch aneurysm	4 (33%)
Ruptured or contained rupture	2 (17%)
Horton disease	1 (8%)

Group A patients had an average age of 71.5 years, 5 were females (56%), 2 patients presented with thoracic arch rupture in the left pleural space. Patient’s characteristics are summarized in Table 1.

Six (67%) patients in Group A had their AA wrap and TEVAR staged with an average 2.4 days between the 2 procedures. Overall, 27 SAV were debranched, 26 surgically, and 1 LSA by laser fenestration. The average diameter of the AA prewrap was 46.5 (41.3-56) mm, and 34.7 (31.9-37.8) mm after the wrap. The average maximum aortic arch sac diameter was 69mm. The other 3 patients of group A had a concomitant repair (AW and TEVAR during the same procedure). All 9 patients (100%) had technical success with deployment of the thoracic endografts, no type 1 or type 3 endoleaks were depicted on completion angiogram. The wrap provided an average proximal seal length of 75.6mm (54.2-97.4). The average ICU stay after the AA wrap was 3.4 days. One patient with Horton disease died within 30 days after the endovascular repair most probably from myocardial infarction.

Early FU (<30 days):

During FU (average FU was 28.4 months), 1 patient with diagnosed left vertebral artery steal underwent a carotid-subclavian bypass 8 weeks after the index surgery. Maximum aortic arch sac diameter went from 69 mm before interventions, to an average of 64.6 mm after interventions on FU CTA. None of the patients had sac growth (>5mm), and all patients discharged (8/9) are still alive.

In Group B (n=3) with prior AW for acute type A aortic dissection, and arch progression during FU, average duration between the wrap and the debranching and TEVAR was 51.5 months. Two patients received arch BEVAR, 1 patient with triple branched arch BEVAR, and the second had a left carotid subclavian bypass and double branched arch BEVAR. The design of arch-branched devices has evolved over time, initially with 2 antegrade branches for the innominate artery and the LCCA (requiring an LSA bypass), then to antegrade branches for the BCT and the LCCA and 1 retrograde branch to the LSA, and finally to an antegrade branch for the BCT and 2o retrograde branches to the LSA and LCC. A total of 7 SAV were debranched. Ascending aorta diameter went from 53mm (49-57) to 38.1mm (35.6-43) after the wrap; the wrap provided a proximal seal zone length of 44.2mm on average. No type 1 or type 3 endoleaks were depicted following TEVAR on completion angiogram. Average FU was 9.7 months, 1 type 2 endoleak was depicted on FU CT scan. None of these patients had stroke and 1 patient died 8 months after surgery from unknown cause. During FU, aortic arch diameter remained stable.

All details regarding the implanted thoracic endografts are included in Table 2.

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Table 2.

TEVAR Details.

Patient	Manufacturer	Proximal diameter	Distal diameter	Number of stentgrafts	Length #1	Length #2	Length #3
1	COOK	46	30	1	243	N/A	N/A
2	COOK	38	38	1	256	N/A	N/A
3	GORE	40	45	1	150	200	N/A
4	COOK	38	38	2	217	217	N/A
5	COOK	42	38	2	225	173	N/A
6	MEDTRONIC	40	34	1	200	N/A	N/A
7	COOK	42	24	2	225	217	N/A
8	COOK	38	38	3	217	225	225
9	COOK	32	46	2	201	N/A	N/A
10	MEDTRONIC	36	36	2	207	150	N/A
11	GORE	40	45	2	200	200	N/A
12	COOK	36	30	2	161	161	N/A
Mean		39	37	1.7	214	197	225

In summary, for the whole cohort, no stroke and 1 death occurred during the perioperative period. Reintervention was required in 3/12 patients in the early postoperative period, and in 1 patient during FU. No type I or III endoleaks were depicted at any time.

Discussion

In our study, we managed to treat aortic arch aneurysms in 12 patients, who were considered at high risk for open replacement of aorta arch and also not candidate for complete endovascular arch repair (arch BEVAR). We performed ascending AW with debranching of the SAV followed by TEVAR. In our practice, this technique is rarely used, because we prefer standard open repair with FET in young patients, especially those with connective tissue disorders, and endovascular branched repair in patients at high risk for a standard open repair. But in this later group, if the AA diameter precludes an exclusive endovascular repair, we propose this alternative hybrid approach.

None of the patients developed clinically a stroke in the postoperative period following AW and TEVAR. One patient died in the perioperative period, she had Horton disease and developed a cardiac arrest 1 week after the TEVAR. This paper showed that surgical or endovascular debranching of supra-aortic trunk vessels with AA wrap associated with TEVAR can be proven as a safe option in this early experience with no stroke, low mortality and reintervention rates. This procedure should be performed in 2 stages, whenever possible, to reduce the cumulative risks associated with the 2 procedures. A single-stage approach was only performed in patients with rupture or symptomatic aneurysms, when immediate aneurysm exclusion is mandatory.

Historically, the gold standard management of arch aneurysms has been open surgical repair,^2,3 through a sternotomy, to perform a frozen elephant trunk repair when distal arch involvement occurs, in 10% of the cases. ⁹ These open repairs have shown worst outcome in high-risk patients, with higher mortality at 30 days (8.8% vs 1.4%; P<0.01) and 1 year (18.1%vs 4.2%, P<0.01). ⁴ Rylski et al ¹⁰ showed that redo open arch repair with underlying coronary artery disease had significantly lower 1-year and 10-year survival. Murana et al ¹¹ showed that frozen elephant trunk repair in high-risk patients can be associated with perioperative risk of stroke up to 18%, spinal ischemia incidence up to 8.2%, and mortality as high as 38% during FU.

Endovascular repair extending to Ishimaru zone 0 with branches to the supra-aortic trunk vessels is an alternative option for these high-risk patients. Multiple studies showed that this repair is associated with low early mortality and acceptable midterm mortality,^12,13 excellent target vessel patency (98%),^14,15 and low reintervention rates (9%). ¹⁶ There is a subset of patients who are high risk for open arch repair, and not candidates for endovascular repair, due to nonfavorable proximal seal zone. Burke et al, assessed the anatomical suitability of the cook zenith branch endograft in 60 patients with nonruptured arch pathology. They found than only 45% had favorable anatomy to accommodate the graft. Large AA diameter and short proximal seal length were the primary reasons for non-feasibility. ¹⁷ Milne et al assessed the suitability of the Cook Zenith branched device in 73 patients with prior open AA replacement for type A dissection. They reported that 71.2% of patients had favorable anatomy. Proximal seal zone was the only cause of exclusion, whether the AA graft was too short (71.4%), graft had a major kink (23.8%), or the graft diameter was too large (4.8%). ¹⁸

In the subgroup of high-risk patients with no appropriate proximal landing zone in the AA, provided that they do not have major aortic valve insufficiency, we believe that a viable option in our armamentarium, is to perform wrapping of the AA and concomitant or staged TEVAR. SAV debranching can be performed with lateral clamping of the AA during the wrap procedure, or endovascularly with an arch BEVAR. In our study, the average diameter of the AA (proximal seal zone diameter) went from 47.7 (41.3-57) mm to 35.6 (31.9-43) mm after the wrap. The wrap provided an average proximal seal length of 68.5 (38.4-97.4) mm. We totally relined the landing zone created by the AA wrap to avoid type IA endoleaks, by implantion of the proximal TEVAR just distal to the SAV debranching proximal suture or to the sino-tubular junction. This required positioning the stiff wire into the left ventricular and right ventricle rapid pacing. Also, we always performed aggressive overlaping between the 2 thoracic endografts (>55mm) to avoid type 3 endoleaks. This is mandatory because of the arch challenging anatomy. Finally, the choice between SAV debranching with a bypass during the AA wrap, or with branches or fenestrations during the endovascular repair was made after preoperative CT scan assessment. Dilated and dissected SAV were best managed by open debranching which was also considered in ruptured or very large aneurysms when the manufacturing delay for a custom-made device was not an option.

As described earlier in details, when performing the AA wrap, the CPB lines and heparin are primed ready on the field during dissection in case there is an aortic or pulmonary artery injury. A previous published study showed that the Teflon sheet provided snug fitting and that prevented its migration. During FU, no sheet migration was observed. Cardiopulmonary bypass was required in 1/35 patients treated for acute type A dissection. ⁸

Pecoraro et al, ¹⁹ in a study involving 26 high risk patients with aortic arch aneurysms, who have nonsuitable proximal seal zone in the AA, showed that AA wrap, supra-aortic vessels (SAVs) debranching and TEVAR technique was associated with 7.7% perioperative mortality, 11.5% neurological events, and 11.5% reintervention rates. One patient developed type 1a endoleak after TEVAR and LSA chimney graft. They reported at 5 years, 82.3% freedom from reintervention and 96% patency of debranched SAVs, and 71.7% survival rate. The difference in their wrapping technique was the use of a polyprolene mesh sutured to the aorta; we used a Teflon sheet, that does not need the tacking suture to the aorta, and therefore lowers the risk of suturing a dilated aorta, referring to a meta-analysis showing lower hospital mortality of 1.5% and reintervention rates on 1.8% when the mesh was not sutured to the aorta. ²⁰ The other difference in that paper, they used chimney technique for nonsurgically debranched vessels, we used laser fenestration and branches, and we believe this is more stable and eliminates the risk of gutter endoleaks.

Preventza el al ²¹ reported their experience of 29 patients with aortic arch aneurysms who are high risk for open replacement with a standard technique under CPB. They performed surgical debranching and zone 0 TEVAR, with aortic wrap performed only in 2 patients with AA diameter between 40 and 45mm. Postoperative mortality and neurological rates was 6.9% and 10.3%, respectively. Overall survival was 79.3% after 58weeks of FU. They reported 1 type1a endoleak 9 months after surgery and 1 type 3 endoleak after 4 years.

The small group of patients and the retrospective design of the study are the main limitations. Owing to the limited number of patients, survival analysis and subgroup comparisons were not performed. Also, there is no comparison with (high risk matched) open arch repair groups, as well as, no comparison to conservative management in high risk matched patients. In a previous publication evaluating aortic wrapping for acute type A dissections, with a mean 36-month FU period for 34 patients, no complications such as dislocation or dilation were observed; long-term data are however not yet available.

Conclusion

Ascending aorta wrap technique with surgical or endovascular debranching of SAVs and zone 0 TEVAR might be good option in patients at high risk for open repair of the arch and with unfavorable proximal seal zone for total endovascular repair.