Outcomes of the Chimney Technique for Endovascular Repair of Aortic Dissection Involving the Arch Branches

Mid-term results of a prospective study for aortic dissection with a gutter-plugging chimney stent graft

OBJECTIVES

Our goal was to access early and mid-term outcomes of a gutter-plugging chimney stent graft for treatment of Stanford type B aortic dissections in the clinical trial Prospective Study for Aortic Arch Therapy with stENt-graft for Chimney technology (PATENCY).

METHODS

Between October 2018 and March 2022, patients with Stanford type B aortic dissections were treated with the Longuette chimney stent graft in 26 vascular centres. The efficiency and the incidence of adverse events over 12 months were investigated.

RESULTS

A total of 150 patients were included. The technical success rate was 99.33% (149/150). The incidence of immediate postoperative endoleak was 5.33% (8/150, type I, n = 6; type II, n = 1; type IV, n = 1) neurologic complications (stroke or spinal cord ischaemia); the 30-day mortality was 0.67% (1/150) and 1.33% (2/150), respectively. During the follow-up period, the median follow-up time was 11.67 (5-16) months. The patent rate of the Longuette graft was 97.87%. Two patients with type I endoleak underwent reintervention. The follow-up rate of the incidence of retrograde A type aortic dissection was 0.67% (1/150). There was no paraplegia, left arm ischaemia or stent migration.

CONCLUSIONS

For revascularization of the left subclavian artery, the Longuette chimney stent graft can provide an easily manipulated, safe and effective endovascular treatment. It should be considered a more efficient technique to prevent type Ia endoleak. Longer follow-up and a larger cohort are needed to validate these results.

CLINICAL TRIAL REGISTRY NUMBER

NCT03767777.

Outcomes of Castor Single-Branched Stent Graft for Reconstruction of Multiple Supra-Aortic Branches in Aortic Arch Disease

PURPOSE

To report the outcomes of a combination of Castor single-branched stent grafts with other techniques for the reconstruction of multiple supra-aortic branches in aortic arch disease.

MATERIALS AND METHODS

Between December 2019 and December 2021, 20 patients with aortic arch disease underwent thoracic endovascular aortic repair (TEVAR) at our institution using a Castor single-branched stent graft combined with the fenestration, chimney, or bypass techniques. Thoracic endovascular aortic repair is indicated for complicated or acute type B aortic dissection (TBAD), nonruptured aneurysms with a maximum aneurysm diameter >5.5 cm or showing rapidly expanded, ruptured, or threatened aneurysms, and penetrating aortic ulcers (PAUs) with a maximal aortic diameter >5.5 cm or with PAUs >10 mm deep or >20 mm in diameter. Preoperative, intraoperative, and postoperative clinical data were recorded.

RESULTS

The median age of the patients was 56 (range=52-69 years) years, and 19 patients were men. Seven patients underwent the Castor single-branched stent graft and left common carotid artery (LCCA) chimney technique, 8 patients underwent the Castor single-branched stent graft and fenestration technique, and 5 patients underwent the Castor single-branched stent graft and bypass technique. The technical success rate was 100%. Major adverse events included 2 endoleaks, 1 spinal cord ischemia, and 1 early-stage retrograde type A aortic dissection. No cerebral stroke-related complications were observed. The mortality rate was 10% (2/20 patients). One patient with thoracic aortic aneurysm (TAA) died because of a sudden decrease in oxygen saturation and blood pressure after surgery. Relatives declined autopsy, and the cause of death was not determined. Another patient died of a retrograde type A dissection after surgery. The median follow-up period was 6 months (range=3.5-12 months). During follow-up, 1 patient with type I endoleak underwent thoracotomy again after a year. The remaining patients recovered well.

CONCLUSIONS

The combination of a Castor single-branched stent graft with fenestration, chimney, or bypass techniques may be an effective treatment for preserving multiple supra-aortic branches in aortic arch disease.

CLINICAL IMPACT

This study introduced three methods of reconstruction of multiple supra-aortic branches using a Castor single-branched stent graft (Castor single-branched stent graft combined with fenestration, chimney, or bypass technique) and analysed their advantages and shortcomings to provide experience for the future treatment of aortic arch diseases.

TEVAR for aortic arch lesions combining physician-modified endograft and in-situ fenestration

BACKGROUND

The aim of this retrospective study was to investigate the outcomes of combining physician-modified endograft (PMEG) and in-situ fenestration (ISF) for aortic arch repair.

METHODS

A retrospective analysis was performed in 12 patients with aortic arch pathologies who underwent thoracic endovascular aortic repair with PMEG and ISF between June 2019 and February 2020.

RESULTS

Revascularizations of supra-aortic arteries were successfully performed in 91.7% patients (11/12). One patient with aberrant right subclavian artery was unsuccessful because of tortuosity and sharp angle. One patient received endovascular exclusion by Viabahn due to artery injury of the femoral access. During the follow-up (mean 22.7 months), one patient underwent Bentall surgery because of retrograde type A aortic dissection, and one patient received coils embolization due to occurrence of a type I endoleak. In addition, one patient died of myocardial infarction 13 months after surgery. Results obtained after computed tomography angiography confirmed patency of all the supra-aortic arteries.

CONCLUSIONS

Combining PMEG and ISF could be a feasible option for aortic arch lesions in selected patients. Long-term durability concerns require further evaluation.

Single-Center Preliminary Experience with Gutter-Plugging Chimney Stent-Graft for Aortic Dissection

PURPOSE

To report the early 2-year results and experience of a novel gutter-plugging chimney stent-graft in a single center that participated in the clinical trial of Prospective Study for Aortic Arch Therapy with stENt-graft for Chimney technology.

MATERIALS AND METHODS

Patients diagnosed with aortic dissection were treated with the novel chimney stent-grafts named Longuette™ for the left subclavian artery revascularization. Primary study outcomes were the incidence of freedom from major adverse events within 30 days and success rate of the operation over 12 months.

RESULTS

A total of 34 patients were enrolled between September 2019 and December 2020. The immediate technical success rate (stent-grafts successfully deployed without fast-flow type Ia or type III endoleak intraoperatively) was 100%, and there were no conversions to open repair. Type Ia and type II endoleaks were noted in three patients (8.8%) and one patient (2.9%) at discharge, respectively. One patient (2.9%) with type Ia endoleak underwent coil embolization at 12 months because of false lumen dilation, and one (2.9%) case of type Ia endoleak resolved spontaneously at 24 months. One chimney stent (2.9%) was revealed with stenosis at discharge and occluded with thrombosis at 6 months postoperatively. During the 2-year follow-up, there was no death, rupture, stroke, paraplegia, left arm ischemia, retrograde dissection, stent-graft induced new entry, or stent migration.

CONCLUSION

The initial results of the Longuette™ stent-graft for revascularization of the left subclavian artery are encouraging with a high technical success rate. Further multicenter follow-up outcomes are required to assess the long-term durability.

LEVEL OF EVIDENCE

Level 4, Case Series.

Ascending Thoracic Aortic TEVAR with Chimney Stent Graft to Free Vein Coronary Bypass for Ruptured Type A Aortic Dissection

The standard treatment for ruptured type A aortic dissection is open surgical repair. We have described the case of a frail patient with home oxygen-dependent chronic obstructive pulmonary disease and prior free vein circumflex coronary artery bypass who had presented with a ruptured type A aortic dissection and was deemed too high risk for open surgery. On July 7, 2017, the patient underwent emergent endovascular ruptured ascending thoracic aortic aneurysm repair with a chimney stent graft to a free vein coronary bypass that originated from the ascending thoracic aorta. The procedure was uneventful, and the patient was discharged home on postoperative day 1.

Systematic Review on Customized and Non-customized Device Techniques for the Endovascular Repair of the Aortic Arch

PURPOSE

Open repair remains the standard of care for aortic arch pathologies. However, endovascular management became an attractive alternative for high-risk patients. This study aimed to assess the outcomes of the available endovascular techniques for aortic arch pathology management.

MATERIALS AND METHODS

A search of the English literature (2000-2022) using PubMed, EMBASE, via Ovid, and CENTRAL databases (February 1, 2022) was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Studies reporting on patients with aortic arch pathologies managed with custom-made devices ([CMDs] fenestrated or branched thoracic endovascular aortic repair [F/BTEVAR]) and non-CMDs (parallel graft or surgeon-modified FTEVAR) were eligible. Studies reporting on hybrid or open repair were excluded. Studies' quality was assessed using the Newcastle-Ottawa Scale. Primary outcomes were technical success, 30 day mortality, and cerebrovascular events (CVEs). Secondary outcomes were re-intervention and mortality during follow-up.

RESULTS

Thirty studies (2135 patients) were included. Treatment indications were mainly dissections (652 cases [48.0%, 652/1358]; 90 type A, 506 type B; 364 acute, 163 chronic) and aneurysms (46.9%, 582/1239). Five studies (211 patients) reported on FTEVAR and 10 (388 patients) on BTEVAR. For FTEVAR, technical success rate was 98.3%. Thirty-day mortality was 3.8% and CVE rate was 12.3%. Ten deaths (9.7%) and 19 re-interventions (9%) were recorded during follow-up (24 months). Regarding BTEVAR, technical success rate was 98.7%, and 30 day mortality and CVE rates were 5.4% and 11.0%, respectively. During follow-up (27 months), 64 deaths (18.7%) and 33 re-interventions (9.6%) were recorded. Parallel graft technique was reported in 11 studies (901 patients). Technical success rate was 76.4%. Thirty-day mortality was 3.9% and 32 (4.3%) CVEs were recorded. Thirty-five deaths (4.4%) and 43 re-interventions (5.5%) were reported during follow-up (27 months). Surgeon-modified FTEVAR was described in 5 studies (635 patients). Technical success rate was 91.6%. At 30 days, 15 deaths (2.3%) and 22 CVEs (3.5%) were recorded. During follow-up (19 months), 26 deaths (4.2%) and 21 re-interventions (3.6%) were detected.

CONCLUSIONS

Endovascular arch repair presented a variable technical success; >95% for F/BTEVAR; ≤90% for non-CMDs. Acceptable 30 day mortality rates were reported. Cerebrovascular event rates ranged up to 10%. These findings, adjacent to the estimated midterm mortality and re-interventions, set the need for further improvement.

CLINICAL IMPACT

Endovascular arch repair gains popularity as a valuable alternative, especially in patients considered unfit for open repair. According the available literature, any endovascular technique, including custom-made or off-the-shelf solutions, may be applied successfully, with acceptable early mortality. However, the perio-operative cerebrovascular event rate is still an issue, indicating the need for further advancements.

Type 1A Endoleak after TEVAR in the Aortic Arch: A Review of the Literature

Aortic arch repair is a challenging intervention. Open surgical repair is still considered the gold standard, but in high-risk patients, it is not always a reasonable option, making endovascular approaches an enticing, when not the only available, alternative for treatment. The strategies more commonly adopted are surgical supra-aortic trunk (SAT) rerouting followed by deployment of a standard thoracic endoprosthesis, chimney techniques, custom-made scalloped, fenestrated, and branched devices, and in situ or physician-modified fenestrations. If we excluded techniques involving SAT rerouting where the arch anatomy is surgically modified in order to make deployment in the aortic arch of a standard thoracic endoprosthesis possible, in the other techniques, one or more SATs are incorporated in the thoracic endoprosthesis. In these cases, no matter what solution is adopted, because of the morphology of the aorta at this level, achieving an ideal sealing is extremely difficult, and endovascular treatments of the arch are burdened by an increased risk of type IA endoleaks. PubMed, EMBASE, and Cochrane Library were searched. We identified 1277 records. After reading titles, abstracts, and full texts, we excluded 1231 records. Exclusion criteria were low-quality evidence, abstracts, case reports, conference presentations, reviews, editorials, and expert opinions. A total of 48 studies were included, for a total of 3114 patients. A type IA endoleak occurred in 248 patients (7.7%) with a mean incidence of 18.8% in chimney procedures, 4.8% and 3%, respectively, in fenestrated and branched devices, and 2.2% in in situ fenestration. We excluded from our analysis scalloped technology that is used when the target vessel originates from a healthy landing zone and represents a different anatomical setting. Type IA endoleaks are a concern with all types of endovascular aortic arch repair, and they can compromise the outcomes of the procedure. The rate of type IA endoleaks appears to be significantly higher in chimney procedures. In order to maximize sealing, whenever possible, endovascular repair of the arch should be achieved with custom-made fenestrated devices. However, chimney configurations are still a valuable solution particularly in the emergency setting, although in such a procedure, to guarantee accurate postoperative management and follow-up, an imaging protocol could be useful.

Outcomes of thoracic endovascular aortic repair with chimney technique for aortic arch diseases

Objective

This study aimed to summarize the long-term experience of using the chimney technique in thoracic endovascular aortic repair (TEVAR) for aortic arch diseases.

Methods

From November 2007 to June 2021, a total of 345 consecutive patients (mean age 56 ± 11.3 years, range 28–83, 302 men) with aortic arch pathologies underwent TEVAR combined with chimney technique (cTEVAR). Their medical data and follow-up results were retrospectively reviewed and analyzed.

Results

Among the 345 patients, 278 (80.6%) received single chimneys, 53 (15.4%) received double chimneys, 7 (2%) received triple chimneys, and 7 (2%) underwent cTEVAR accompanied by other techniques (two with extra-anatomical bypass, two with in situ fenestration, and three with physician modified fenestration). A total of 412 chimney stents were used, including 27 in the innominate artery (IA), 113 in the left common carotid artery, 270 in the left subclavian artery, and two in the aberrant right subclavian artery. Early type IA endoleaks were found in 38 (11%) patients, including 12 with the double or triple chimney technique. Early type II endoleak was found in nine (2.6%) patients. Early re-intervention occurred in two patients with double chimney technique, one for chimney stent migration and the other for compression of chimney stent. The 30-day mortality was 1.2% (4 in 345). During a mean follow-up of 42 ± 22 months (range 1–108 months), major stroke occurred in nine (2.6%) patients, chimney occlusion or stenosis occurred in six (1.7%), and retrograde type A aortic dissection occurred in four (1.2%). Fourteen (4.1%) patients received the secondary intervention. The all-cause mortality was 6.7% (23 in 345). Additionally, the total adverse event rate after cTEVAR was 13.9% (48 in 345).

Conclusion

TEVAR with chimney technique provides a minimally invasive alternative with good chimney graft patency and low postoperative mortality during follow-up. However, the double and triple chimney techniques should be used cautiously as they seem to have a higher risk for type IA endoleak and adverse events after the operation.

Aortic Dissection: Branched, Fenestrated, and Parallel Aortic Stent Grafts in the Ascending Aorta and Arch

Open surgical repair of dissections and post-dissection degenerative aneurysms involving the ascending thoracic aorta and aortic arch, whether in the acute or post-repair state, is associated with high rates of morbidity and mortality. Recent advancements in minimally invasive endovascular techniques have expanded the role of thoracic endovascular aortic repair (TEVAR) for dissections and dissection-related arch pathologies. Image-guided endovascular techniques, such as in situ fenestrated grafts, chimney and/or periscope grafts, along with newly developed commercially available branched aortic devices, have allowed for an increasing number of high-risk operative candidates to undergo definitive repair of aortic arch pathology who otherwise would have been destined for non-operative management. This paper reviews the data, pre-procedural planning, and technical considerations for complex TEVAR techniques for ascending and aortic arch dissections and dissection-related aneurysms.

Outcomes of Total Endovascular Aortic Arch Repair with Surgeon-Modified Fenestrated Stent-Grafts on Zone 0 Landing for Aortic Arch Pathologies

OBJECTIVES

This study evaluated the feasibility and safety of total endovascular aortic arch repair with surgeon-modified fenestrated stent-graft on zone 0 landing for aortic arch pathologies.

METHODS

Between June 2016 and October 2019, 37 consecutive patients underwent total endovascular arch repair with surgeon-modified fenestrated stent-grafts on zone 0 landing. Outcomes included technical success, perioperative and follow-up morbidity and mortality, and branch artery patency.

RESULTS

During the study period, 37 patients were treated with total endovascular aortic arch repair with surgeon-modified fenestrated stent-graft. Twenty-one (56.8%) patients were diagnosed with aortic dissections, 15 (40.5%) patients with aneurysms, and 1 (2.7%) patient required reintervention due to endoleak and sac expansion from previous thoracic endovascular aortic repair for thoracoabdominal aneurysm. The proximal landing zone for all patients were in zone 0, and all branch arteries of aortic arch were reconstructed. Technical success was achieved in 34 cases (91.9%). Three (8.1%) patients had fenestrations misaligned with target arteries, and the chimney technique was applied as a complementary measure. Thirty-day mortality rate was 5.4% (n=2). Thirty-day stroke rate was 5.4% (n=2). Thirty-day reintervention rate was 2.7% (n=1). At a median follow-up of 20 months (range, 3-49 months), 5 (13.5%) patients died, including 2 aortic-related deaths, 1 nonaortic-related death, and 2 deaths of unknown reason. One (2.7%) patient had stroke. Four patients (10.8%) had reintervention during the follow-up, including 2 cases of left subclavian artery occlusion and 2 cases of type II endoleak. The estimated survival (±SE) at 2 years was 72.4%±9.7% (95% CI 53.4%-91.4%). The estimated freedom from reintervention (±SE) at 2 years was 87.4%±5.9% (95% CI 75.84%-98.96%).

CONCLUSIONS

Total endovascular aortic arch repair with surgeon-modified fenestrated stent-grafts on zone 0 landing is an alternate option for the treatment of aortic arch pathologies in experienced centers.

Long-Term Outcomes of Thoracic Endovascular Repair for Aortic Arch Dissection Using Customized Single-Branched Fenestrated Stent-Graft

OBJECTIVES

To report outcomes of thoracic endovascular repair using customized single-branched fenestrated stent-grafts in treatment of aortic arch dissections.

MATERIALS AND METHODS

Between November 2009 and November 2011, 16 patients with aortic arch dissections underwent thoracic endovascular aortic repair utilizing customized unibody single-branched fenestrated stent-graft (UBFSG) in our institution.

RESULTS

All 16 patients were male with mean age of 54.50 ± 11.33. The technical success rate was 100%. 30-day mortality rate was 6.25% (n = 1). The median follow-up period was 98 months (range, 0-119). During follow-up, 4 nonaorta-related deaths were recorded. Two (2) cases of left subclavian artery occlusion were observed 12 and 14 months after the operation. Two (2) patients had another successful endovascular repair in time, including one case of type Ib endoleak occurred 100 months after the operation and one case of stent-graft induced new entry tear 38 months after the operation. No stroke and migration of stent-grafts were observed.

CONCLUSIONS

The branched fenestrated stent-graft may be an effective alternative treatment for aortic arch dissections unfit for open surgery.

Endovascular management of chronic post-dissection aneurysms of the aortic arch

This article reviews endovascular management of chronic post-dissection aneurysms of the aortic arch. Therapeutic strategies intended for this complex aortic condition are evolving rapidly to allow the treatment of various hostile aortic anatomy and frail patients. Principles, technical considerations, devices and outcomes of each technique are reviewed and summarized. Hybrid repair offer similar early mortality and stroke rates compared to open conventional surgery. Arch chimney and other parallel graft techniques present poor long term outcome, and should be limited to emergency situations where no other option is available. Fenestrated stent-grafting is subjected to many technical challenges in aortic arch due to difficulties in stent-graft orientation and fenestration positioning. In situ fenestration is an off-label technique that should only be used as an emergency bailout maneuver, considering that temporary coverage of supra aortic trunk vessel and its long-term durability raise concern. Finally, in experienced hands and appropriate anatomic conditions, arch branched graft technology has shown itself to be a safe and effective alternative to open conventional surgery. No randomized controlled trials have yet compared total endovascular aortic arch repair with hybrid techniques and open arch repair. The management of chronic post-dissection aneurysms of the aortic arch is challenging, decision-making and interventions should continue to be performed in high-volume centers with a dedicated aortic team with an expertise in both open and endovascular repairs.

Off-the-Shelf Devices for Treatment of Thoracic Aortic Diseases: Midterm Follow-up of TEVAR With Chimneys or Physician-Made Fenestrations

Purpose: To evaluate the midterm outcomes of thoracic endovascular aortic repair (TEVAR) using chimney grafts (ch-TEVAR) or thoracic stent-grafts with fenestrations made on the back table (f-TEVAR) to treat thoracic aortic dissection (TAD) and thoracic aortic aneurysm (TAA). Materials and Methods: A retrospective analysis was conducted of 474 consecutive patients (mean age 62.3±10.7 years; 346 men) treated with either f-TEVAR (n=110) or ch-TEVAR (n=364) for 352 TADs (81 f-TEVAR and 271 ch-TEVAR) or 122 TAAs (29 f-TEVAR and 93 ch-TEVAR) from 2008 to 2016. The primary endpoints at 30 days and during follow-up were overall mortality, aorta-related mortality, and major complications. The secondary endpoints were endoleak and reintervention. The patency of the target branches, cost of hospitalization, and the use of antiplatelet drugs were also analyzed. Results: Intraoperative type I endoleaks were treated in 69 (14.6%) cases (4 f-TEVAR and 65 ch-TEVAR, p<0.01) to achieve 100% technical success. Four (0.8%) patients died within 30 days [1 (0.9%) f-TEVAR and 3 (0.8%) ch-TEVAR]. Perioperative cerebral ischemia (1 fatal stroke) occurred in 9 (1.9%) patients: (1 f-TEVAR and 8 ch-TEVAR, p=0.39). During the mean follow-up of 50.6±20.0 months (49.5±18.3 months in f-TEVAR and 50.9±20.6 months in ch-TEVAR), 11 (2.3%) patients died of an aorta-related event. Type I endoleak was present in 40 (8.4%) patients (1 f-TEVAR and 39 ch-TEVAR, p<0.01). Eleven (2.3%) patients experienced stent-graft migration and 13 (2.7%) had a retrograde dissection. One hundred (16.9%) of the 593 branch stents occluded (4/75 in the f-TEVAR group and 96/518 in the ch-TEVAR group, p<0.01). The branch reintervention rate was 7.2% (34/474). The f-TEVAR group had a significantly higher probability of freedom from branch occlusion (92%) than the ch-TEVAR group (83%, p=0.007). Conclusion: Off-the-shelf techniques employing chimney grafts and homemade fenestrations are both suitable options for TAD and TAA involving the supra-aortic branches, with a low incidence of reintervention. Fenestrated TEVAR seems to have more favorable short- and midterm outcomes. Further study of these off-the-shelf techniques for aortic arch repair is warranted.

A Novel Internal and External Bypass Method to Safeguard Cerebral Blood Flow During Aortic Arch Endovascular Repair Requiring Triple In Situ Fenestrations

Purpose: To report a novel internal and external blood bypass method for cerebral protection during in situ triple-fenestrated stent-graft repair in the aortic arch. Technique: A method was devised to combine internal and external blood bypass circuits to preserve cerebral blood flow when all 3 supra-aortic branches are covered by the stent-graft. Long 14-F to 18-F introducers are placed retrogradely into the right and left common carotid arteries (CCAs). Smaller sheaths are placed antegradely into the internal carotid arteries (ICAs) bilaterally and into the right CCA introducer, which has had an aperture cut into it for flow to pass into the smaller sheath. The right CCA introducer is positioned in the ascending aorta to supply the innominate artery; the smaller sheath in the right CCA introducer is positioned at the aperture. The small sheath in the right CCA is connected to the left ICA sheath, and the left CCA fenestration is made and stented. The left ICA sheath is connected to the right ICA sheath, and the right CCA introducer is pulled back to the origin of the innominate artery and the smaller sheath removed. The fenestrations for the innominate and left subclavian arteries are opened sequentially. In 8 patients, complete bypass to maintain brain perfusion was performed for an average 17.6±6.9 minutes; intraoperative transcranial Doppler monitoring during flow bypass showed no notable decline in intracranial blood flow velocity. Two patients suffered stroke; one recovered completely. Conclusion: A cerebral protection strategy that integrates internal and external blood flow bypass techniques to maintain adequate brain blood flow is simple and feasible for in situ triple-fenestration aortic arch stent-graft repairs. However, neurological complications were not avoided with this method; thus, further research and development are required.