Chimney Grafts in Aortic Stent Grafting: Hazardous or Useful Technique? Systematic Review of Current Data

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 thoracic endovascular aortic repair with physician-manufactured partial micropore stent grafts for aortic arch pathologies

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has been used extensively in the management of thoracic aortic diseases. Numerous efforts have been made to enhance clinical outcomes through the use of stent grafts. This study aimed to investigate the effectiveness and safety of physician-manufactured partial micropore stent grafts (PSMGs) in TEVAR.

METHODS

Between December 2017 and June 2022, data were collected from 56 patients who underwent TEVAR using physician-manufactured PSMGs. The evaluation encompassed technical success, perioperative and follow-up morbidity and mortality, stroke incidence, and branch artery patency.

RESULTS

In this investigation, 56 patients received treatment with physician-manufactured PSMGs. Of these patients, 46 were male, with a mean age of 62.1 ± 11.2 years. Aortic pathologies comprised aortic dissection (n = 31 [55.4%]), aortic aneurysms (n = 10 [17.9%]), penetrating aortic ulcer (n = 8 [14.3%]), and intramural hematoma (n = 7 [12.5%]). During a median follow-up of 18 months (interquartile range, 13-25 months), the stroke rate, supra-aortic branch patency rate, and endoleak rate were 0%, 100%, and 7.1%, respectively. There were no occurrences of all-cause mortality, stroke, or the necessity for open conversion.

CONCLUSIONS

TEVAR with physician-manufactured PSMGs is a viable alternative for addressing aortic arch pathologies in proficient medical centers. The approach demonstrates favorable branch patency, a low complication rate, and minimal postoperative mortality.

Preclinical Evaluation of a Modular Inner-Branched Stent Graft to Reconstruct the Left Subclavian Artery in Thoracic Endovascular Aortic Repair: Experimental Study in Pigs

PURPOSE

In approximate 40% of thoracic endovascular aortic repair (TEVAR) procedures, the left subclavian artery (LSA) needs to be covered to obtain sufficient proximal sealing zone. To preserve the LSA during the TEVAR for type B aortic dissection (TBAD) adjacent to LSA, our team designed a modular single inner-branched stent graft. This study was performed to evaluate the safety and feasibility of deploying a modular single inner-branched stent graft in a porcine model.

MATERIALS AND METHODS

Modular inner-branched stent grafts were implanted in 14 pigs via right femoral and right carotid arterial access. Computed tomography angiography (CTA) and angiography were performed in all pigs to appraise the morphological characteristics of the stent grafts at the end of follow-up. The pigs were then euthanized, and tissues were collected for gross and histological examination.

RESULTS

The technical success rate was 100% (14/14). One pig suddenly died 5 hours after operation, and 1 pig died after completing the follow-up CTA. During the follow-up period, all surviving pigs showed good mental state, normal diets and activities. Computed tomography angiography examinations showed that all stent grafts were intact without fracture. All bridging covered stents were patent. Angiography showed that the position, shape, and adhesion of the stent grafts were good, and no obvious endoleaks were found. Histological examination showed that the biocompatibility of the stent grafts was good.

CONCLUSIONS

This study's outcomes demonstrate that it is safe and feasible to deploy a modular single inner-branched stent graft in a porcine model.

CLINICAL IMPACT

This device is the first modular device designed to treat TBAD adjacent to LSA in China. This device is a modular two-component system consisting of a thoracic aortic stent graft with a retrograde inner branch and a bridging covered stent. The modular design and the retrograde inner branch are the two important innovations of this device. Theoretically, the device could make it easier and safer for clinicians to treat TBAD adjacent to the LSA.

Cleaning Up the Chimney: Early Renal Stent Graft Thrombosis Following Endovascular Treatment of a Juxtarenal Aortic Aneurysm With the Chimney Technique

The endovascular management of juxtarenal aortic aneurysms with the chimney technique (ch-EVAR) has gained popularity in recent years. It provides an alternative to open repair, allowing treatment of challenging anatomies with devices readily available in any vascular suite. The primary drawback persists as the occurrence of type-Ia endoleak from gutters and renal stent thrombosis. We present two cases of early renal stent graft thrombosis following chimney endovascular aneurysm repair. The first patient was an 80-year-old man who underwent single ch-EVAR and came back on the fifth post-op day with renal stent graft thrombosis. He was re-operated for recanalization and additional stenting of his chimney graft. The patient recovered well with no complications. The second case involved a 72-year-old man with a juxtarenal aneurysm, treated with ch-EVAR on both renal arteries. Unfortunately, on the 10th post-op day, he was referred to our department due to lumbar pain and acute renal failure due to chimney graft thrombosis bilaterally. The left renal chimney graft was recanalized by endovascular means. On the contrary, despite efforts of the endovascular and open approach, the right chimney graft and the right renal artery remained occluded. While ch-EVAR is a viable and off-the-shelf solution for urgent and complex juxtarenal aortic aneurysms, it should be performed with awareness of the potential for graft thrombosis and persistent endoleaks. Despite these complications, the chimney technique can still be a viable treatment option. A better understanding of the indications and advancements in the devices used can lead to better long-term results.

Results of the Chimney Technique in a Community Hospital

BACKGROUND

The chimney technique, fenestrated or branched endovascular aortic repair are endovascular options in patients with a juxtarenal, suprarenal or type IV thoraco-abdominal aneurysm. The chimney technique has specific advantages and disadvantages. A retrospective single center study was performed to describe the results.

PATIENTS AND METHODS

All consecutive patients in whom the chimney technique was used between 1th January 2011 and 31th December 2020 were included. We excluded patients who needed a revision of an existing EVAR and patients with a para-anastomotic aneurysm. Outcomes were reported in accordance with the reporting standards.

RESULTS

38 Patients were included in the study, a total of 59 chimney grafts were deployed. At a median follow-up duration of 26.6 months, there were 9 patients with occlusion of the chimney graft. In 1 patient an iliac renal bypass was performed. In the other patients the renal function stabilized and no further therapy was necessary. All chimneys in the mesenteric arteries remained patent. Gutter endoleak was seen in 5 patients, 3 patients were successfully treated and in the other 2 patients the gutter endoleak disappeared spontaneously.

CONCLUSIONS

Conclusions should be drawn carefully as this is a retrospective non-comparative study. Results from 38 patients treated with the chimney technique are presented. Chimney graft occlusion rate was 15.3% at the end of follow-up. However, the majority (77.8%) of the occluded stents were self-expandable stents, stressing the importance of selecting the right devices.

Bibliometric analysis of the top 100 most-cited articles on branch reconstruction in endovascular aortic repair

With the global acceptance of endovascular aortic repair (EVAR) for aortic diseases, one of the most common issues in EVAR is the preservation of critical aortic branches. Despite the fact that many studies on EVAR-assisted endovascular branch reconstruction techniques have been published. There were few bibliometric analyses that focused on branch rebuilding in endovascular aortic repair. In this study, we aim to analyze the characteristics of the 100 most-cited articles on branch reconstruction in Endovascular Aortic Repair. The most popular articles retrospectively searched on the Web of Science were published between 1999 and 2018, with 10480 citations in total (an average of 551.58 citations per year). The top-cited article was 281 citations. The peak years of citations was 2019 (1051 citations). Journal of Vascular Surgery published the most articles (46 articles) and was the most-cited journal (5055 citations), and the United States was the country with the greatest number of publications (43 articles). Cleveland Clinic was the most influential institution with 20 articles. Fenestration technique was the major topic area of interest and trend (63 articles mentioned). Customised device was the most widely used endograft (52 articles mentioned). Renal artery was the most frequently reconstructed branch of aorta (70 articles mentioned). Our analysis showed the endovascular branch reconstruction in EVAR developed rapidly over the past 20 years. Continued exploration and cooperation between specialties and manufacturers on endograft design and modifications will further enhance knowledge of disease intervention and treatment.

Preliminary Outcomes of Zone 2 Thoracic Endovascular Aortic Repair Using Castor Single-Branched Stent Grafts: A Single-Center Experience

In the context of thoracic endovascular aortic repair (TEVAR), the reconstruction of the left subclavian artery (LSA) has emerged as a crucial component in establishing a sufficient proximal landing zone. However, the technical difficulty of these procedures raises the possibility of endoleaks and neurological consequences. Single-branched stent grafts offer good anchoring and LSA flow for these patients. This study evaluates the feasibility of utilizing novel single-branched stent grafts in the treatment of distal aortic arch disease, identifying good results in the short and medium term. From September 2019 to March 2023, TEVAR and revascularized LSA were performed on ten patients at the Ospedale del Cuore-FTGM in Massa, Italy, using Castor single-branched thoracic aortic stent grafts (Microport Medical, Shanghai, China). The authors' first findings demonstrated that, after an average follow-up of one year, the Castor branching aortic stent graft system was safe and achieving an appropriate proximal landing zone and maintaining sufficient LSA perfusion was possible. With regard to the endovascular treatment of distal aortic arch diseases, this product offers a compelling substitute for surgery. For the purpose of assessing the long-term effectiveness of this approach, the follow-up period should be extended.

Chimney Technique and Single-Branched Stent Graft for the Left Subclavian Artery Preservation During Zone 2 Thoracic Endovascular Aortic Repair for Type B Acute Aortic Syndromes

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of zone 2 thoracic endovascular aortic repair assisted by the chimney technique or single-branched stent graft for the preservation of the left subclavian artery, and summarize our single-center experience with the techniques.

MATERIALS AND METHODS

From February 2017 to June 2020, 137 patients who underwent left subclavian artery revascularization during zone 2 thoracic endovascular aortic repair were enrolled. Patients had acute type B aortic dissection and penetrating aortic ulcer associated with intramural hematoma. The chimney technique was performed in 68 patients (group A), and single-branched stent graft was deployed in 69 patients (group B). All procedures were performed during the acute phase. Primary technical success, immediate postoperative endoleak, neurologic complications (stroke or spinal cord ischemia), 30-day mortality, 1-year technical success, all-cause mortality, patency of the left subclavian artery, and reintervention were analyzed. Comparing the occurrence of the Bird-Beak Configuration, defined as a gap between the aortic wall and the sent graft with stent protrusion into the aortic lumen more than 5 mm, was also performed.

RESULTS

Primary technique success was achieved in 66 and 67 patients in groups A and B, respectively. The incidence of immediate postoperative endoleak, neurologic complications (stroke or spinal cord ischemia), and 30-day mortality were 5.9%, 1.5%, and 4.4% in group A, and 2.9%, 2.9%, and 2.9% in group B, respectively. During follow-up, the 1-year technical success rate was similar in both groups. All-cause mortality was similar in both groups (3.1% in group A and 4.5% in group B). The patency of the left subclavian artery was not significantly different between the 2 groups with 2 and 3 occlusions in groups A and B, respectively. The rate of reintervention was higher in group B (3.1% vs 1.6%, p=0.536), with a non-significant difference. Bird-Beak Configuration was more prominent in group B with the incidence of 59.42%.

CONCLUSIONS

Acting as minimally invasive alternatives, both techniques are feasible for left subclavian artery preservation during zone 2 thoracic endovascular aortic repair for type B acute aortic syndromes with encouraging mid-term outcomes. Long-term follow-up is required to confirm these findings.

Brazilian Society for Angiology and Vascular Surgery guidelines on abdominal aortic aneurysm

The Brazilian Society of Angiology and Vascular Surgery, through the Guidelines Project, presents new Abdominal Aortic Aneurysm Guidelines, on the subject of care for abdominal aortic aneurysm patients. Its development prioritized descriptive guidelines, using the EMBASE, LILACS, and PubMed databases. References include randomized controlled trials, systematic reviews, meta-analyses, and cohort studies. Quality of evidence was evaluated by a pair of coordinators, aided by the RoB 2 Cochrane tool and the Newcastle Ottawa Scale forms. The subjects include juxtarenal aneurysms, infected aneurysms, and new therapeutic techniques, especially endovascular procedures. The current version of the guidelines include important recommendations for the primary topics involving diagnosis, treatment, and follow-up for abdominal aortic aneurysm patients, providing an objective guide for medical practice, based on scientific evidence and widely available throughout Brazil.

Fenestrated Physician-Modified Endografts for Preservation of Main and Accessory Renal Arteries in Juxtarenal Aortic Aneurysms

BACKGROUND

There is a paucity of reporting outcomes of complex aortic aneurysm treatment such as juxtarenal abdominal aortic aneurysms, where additional techniques to preserve renal artery perfusion are required.

METHODS

Retrospective analysis of consecutive patients who underwent emergent and elective aortic repair with fenestrated PMEGs between March 2019 and January 2023. Endpoints were technical success, reinterventions, secondary reinterventions and target vessel patency.

RESULTS

Forty-seven target vessels in 37 patients (23 male, median age 75 years) were targeted, of which 44 were renal arteries (RAs) with a mean diameter of 5.4 ± 1.0 mm. Thirteen were accessory RAs and six had a diameter ≤ 4 mm. Technical success rate was 87% overall; 97% for main and 62% for accessory RAs respectively. Target vessel patency and freedom from secondary reintervention was 100% and 97% at 30 days and 96% and 91% at one year, respectively. There was no 30-day mortality.

CONCLUSION

Fenestrated physician-modified endografts are safe and effective for the treatment of patients with juxtarenal abdominal aortic aneurysms when incorporating main renal arteries. Limited technical success may be expected when targeting accessory renal arteries, especially when small in diameter. Long-term follow-up is needed to confirm durability of PMEGs for renal artery preservation.

Complete zone 0-10 aortic endovascular reconstruction

To the best of our knowledge, the present report is the first on the safety and efficacy of complete endovascular aortic reconstruction from zone 0 to 10 using a standardized approach and parallel stent graft configurations in high-risk patients considered unfit for surgery. During a 7-year period, five patients with complex thoracoabdominal aortic aneurysms and dissections involving zone 0-10 presented with rupture (n = 1; 20%), were symptomatic (n = 2; 40%), or had an aortic pseudoaneurysm (n = 2; 40%) and underwent complete endovascular zone 0-10 reconstruction using off-the-shelf stent grafts in parallel configurations that included chimneys, periscopes, and endovascular docking stations. The zone 0-5 complete arch chimney thoracic endovascular repair included chimneys that extended from the ascending thoracic aorta to the innominate, left common carotid, and left subclavian arteries and a thoracic stent graft extending from zone 0 to 5. The zone 5-10 aortic reconstructions were staged. Stage 1 included either thoracic stent graft and antegrade four visceral chimney placement or abdominal aortic stent graft and retrograde four visceral chimney placement. Stage II included completion of the remainder of the aortic reconstruction with cerebrospinal fluid drainage. A total of 15 aortic procedures included 34 chimneys (14 aortic arch and 20 visceral). Two patients (40%) underwent zone 0-5 aortic reconstruction first, and three patients (60%) underwent zone 5-10 aortic reconstruction first. The incidence of 30-day mortality, spinal cord ischemia, myocardial infarction, stroke, and visceral ischemia was 0%. At a mean follow-up of 4.5 ± 3.1 years, the aortic reconstruction-related mortality was 0%. All-cause mortality was 20%; one patient had died of pneumonia at 3 years postoperatively. Two endoleaks each occurred in zone 0-5 and zone 5-10 (40% for both groups). All endoleaks were treated with coil embolization. Complete endovascular zone 0-10 aortic reconstruction using parallel stent grafts with a docking station is a feasible and relatively safe technique that offers the ability to customize off-the-shelf devices for the treatment of high-risk patients with limited morbidity and mortality.

Mid-term outcomes of left subclavian artery revascularization with Castor stent graft in treatment of type B aortic dissection in left subclavian artery

Background

Here we analyzed mid-term data of thoracic endovascular aneurysm repair (TEVAR) surgery with Castor single-branched stent graft placement for the management of Stanford type B aortic dissection (STBAD) involving the left subclavian artery (LSA).

Methods

Between April 2014 and February 2019, 32 patients with STBAD involving a Castor single-branched stent graft were included. We analyzed their outcomes, including technical success rate (TSR), surgical duration (SD), presence of ischemia, perioperative complications, LSA patency, and survival rate (SR), using computed tomography angiography and clinical evaluation during mid-term follow-up.

Results

The mean patient age was 54.63 ​± ​12.37 years (range, 36-83 years). The TSR was 96.88% (n ​= ​31/32). The mean SD was 87.44 ​± ​10.89 with a mean contrast volume of 125.31 ​± ​19.30 ​mL. No neurological complications or deaths occurred during the study period. The patients had a mean hospital stay of 7.84 ​± ​3.20 days. At a mean follow-up of 68.78 ​± ​11.26 months, four non-aortic deaths (12.5%) were observed. The LSA patency rate was 100% (n ​= ​28/28). There was only one case of type I endoleak immediately after surgery (3.12%) (type I from LSA). However, none of the patients experienced type II endoleaks, and there were no cases of retrograde type A aortic dissection or stent graft-driven new distal entry. Finally, all patients exhibited good LSA patency.

Conclusion

TEVAR using a Castor single-branched stent graft may be a highly feasible and efficient procedure for the management of STBAD involving the LSA.

Efficacy of left subclavian artery revascularization strategies during thoracic endovascular aortic repair in patients with type B dissection: A single-center experience of 105 patients

Background

Left subclavian artery (LSA) revascularization during thoracic endovascular aortic repair (TEVAR) is necessary to reduce postoperative complications in patients with Stanford type B aortic dissection and an insufficient proximal anchoring area. However, the efficacy and safety of different LSA revascularization strategies remain unclear. Here, we compared these strategies to provide a clinical basis for selecting an appropriate LSA revascularization method.

Methods

In this study, we included 105 patients with type B aortic dissection who were treated using TEVAR combined with LSA reconstruction in the Second Hospital of Lanzhou University from March 2013 to 2020. They were divided into four groups according to the method used for LSA reconstruction, namely, carotid subclavian bypass (CSB; n = 41), chimney graft (CG; n = 29), single-branched stent graft (SBSG; n = 21), and physician-made fenestration (PMF; n = 14) groups. Finally, we collected and analyzed the baseline, perioperative, operative, postoperative, and follow-up data of the patients.

Results

The treatment success rate was 100% in all the groups, and CSB + TEVAR was the most commonly used procedure in emergency settings compared with the other three procedures (P < 0.05). The estimated blood loss, contrast agent volume, fluoroscopic time, operation time, and limb ischemia symptoms during the follow-up were significantly different in the four groups (P < 0.05). Pairwise comparison among groups indicated that the estimated blood loss and operation time in the CSB group were the highest (adjusted P < 0.0083; P < 0.05). The contrast agent volume and fluoroscopy duration were the highest in the SBSG groups, followed by PMF, CG, and CSB groups. The incidence of limb ischemia symptoms was the highest in the PMF group (28.6%) during the follow-up. The incidence of complications (except limb ischemia symptoms) during the perioperative and follow-up periods was similar among the four groups (P > 0.05) The median follow-up time of CSB, CG, SBSG, and PMF groups was significantly different (P < 0.05), and the CSB group had the longest follow-up.

Conclusion

Our single-center experience suggested that the PMF technique increased the risk of limb ischemia symptoms. The other three strategies effectively and safely restored LSA perfusion in patients with type B aortic dissection and had comparable complications. Overall, different LSA revascularization techniques have their advantages and disadvantages.

Surgical treatment patterns and clinical outcomes of type B aortic dissection involving the aortic arch

OBJECTIVE

In the present report, we have described the outcomes of endovascular repair, hybrid arch repair, and open surgical repair for type B dissection involving the aortic arch (B_{1-2, D}).

METHODS

Cases of endovascular repair, hybrid arch repair, and open surgical repair performed between January 2015 and December 2019 for aortic dissection designated as B_{1-2, D} by the Society for Vascular Surgery/Society of Thoracic Surgeons classification were retrospectively analyzed. The primary end point was all-cause mortality at follow-up. The secondary end points included early mortality, early morbidities, and aortic-related late events. Kaplan-Meier curves were created to analyze survival from all-cause mortality and freedom from aortic-related late events in the endovascular, hybrid, and open groups. Propensity score matching and stratification (stratified by proximal dissection extension: B_{1, D} and B_{2, D}) were performed as sensitivity analyses to compare the outcomes among the three treatment patterns after controlling for major confounders.

RESULTS

The present study included 151 patients (men, 79.5%; mean age, 47.3 ± 10.5 years), with 72 (47.7%) in the endovascular group, 46 (30.5%) in the hybrid group, and 33 (21.8%) in the open group. No significant difference was noted in early mortality between the endovascular, hybrid, and open groups (1.4% vs 2.2% vs 3.0%; P = .791). The incidence of early endoleak was significantly greater (33.3% vs 13.0% vs 6.1%; P = .002) and the incidence of renal function deterioration was less (4.2% vs 26.1% vs 24.2%; P = .001) after endovascular repair vs hybrid arch repair and open surgery. After a median follow-up of 40.0 months (range, 0-84.0 months), no significant differences were found in all-cause mortality (5.6% vs 4.3% vs 3.0%; P = 1.0), aortic-related late events (16.7% vs 15.2% vs 12.1%; P = .834), or late endoleak (9.7% vs 4.3% vs 6.1%; P = .630) after endovascular, hybrid, and open surgery. The propensity score matching and stratification analyses displayed consistent outcomes for early mortality, all-cause mortality, and aortic-related late events among the three groups.

CONCLUSIONS

The mid- to long-term outcomes after endovascular repair, hybrid arch repair, and open surgical repair for type B dissection involving the aortic arch (B_{1-2, D}) were favorable and comparable in selected patients. Extensive experience and multidisciplinary teamwork are prerequisites for individualized strategies for repair of B_{1-2, D}.

Endovascular repair using parallel grafts to treat a suprarenal pancreatitis-related abdominal aortic pseudoaneurysm

Arterial pseudoaneurysms represent an uncommon complication of acute pancreatic inflammation or chronic pancreatitis. We describe a contained rupture of a suprarenal abdominal aortic pseudoaneurysm. An aorto-uni-iliac stent-graft was adopted as the aortic main body and was combined with two chimneys and two periscope stents for celiac/superior mesenteric artery and renal arteries, respectively. The procedure was complicated by the entrapment of the celiac sheath into the barbs of the aortic stent-graft and the attempts to remove the sheath resulted in an upward migration of the stent-grafts. A bail-out endovascular procedure was used to reline the stent-grafts and the pseudoaneurysmal sac was embolized with coils.

Chimney Stenting Versus Surgical Debranching for the Treatment of Aortic Arch Pathologies-A Propensity-Matched Analysis

BACKGROUND

Endovascular repair of aortic arch lesions requires revascularization of epiaortic vessels in case of coverage. The objective of this study was to compare the outcomes of surgical bypass versus endovascular reconstruction with a chimney graft.

METHODS

A retrospective analysis of a multicenter register between January 2005 and December 2019 was performed. A total of 127 patients were included and divided into 2 groups: thoracic endovascular aortic repair + surgical debranching (n = 72) and thoracic endovascular aortic repair + chimney stenting (n = 55). The main end points were major neurologic sequelae and type IA endoleak. Propensity score matching was performed to analyse baseline variables related to these outcomes.

RESULTS

The mean follow-up was 35.6 months for the debranching group and 34.1 for the chimney group (P = 0.65). The incidence of stroke was higher in the chimney group although not statistically significant (7.3% vs. 4.1%; P = 0.46); for both groups, a wide angle between the ostium of the target vessel and the aorta and landing in Ishimaru Zone 0 was found to be the main predictors for major neurologic sequelae (P = 0.002 and P = 0.003, respectively). During follow-up, 9 (12.5%) type IA endoleaks occurred in the debranching group and 12 (21.8%) in the chimney group (P = 0.14). Aortic diameter larger than 66 mm and arch angle >46° had a strong association with proximal endoleak incidence (P = 0.001 and P = 0.011, respectively) CONCLUSIONS: Surgical debranching showed better results than chimney stenting in terms of major neurologic events incidence and type IA endoleak, although the difference between the groups was not statistically significant. Further research with larger cohorts is needed to establish the indications for these procedures.

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.

Hybrid and endovascular approaches to the aortic arch

PURPOSE OF REVIEW

The gold standard treatment for aneurysms and dissections involving the aortic arch remains open total arch replacement. High-risk operative candidates may benefit from hybrid or completely endovascular techniques to reduce the risk of perioperative mortality and morbidity.

RECENT FINDINGS

Numerous endografts are available for investigational use in the aortic arch as part of investigational device exemption (IDE) programs. Some are fenestrated or scalloped, whereas others are branched, ranging from single branch to triple branch stent-grafts. Initial results for completely endovascular repair of the aortic arch are encouraging. Current data estimates that rates of successful deployment of arch endografts ranges from 84.2% to 100%, whereas operative mortality may be as high as 13.2%, with stroke rates being as high as 20% and spinal cord ischemia being as high as 3.1%.

SUMMARY

More data are necessary to compare hybrid and endovascular stent-grafting of the aortic arch to conventional open total arch replacement. Longitudinal follow-up is also lacking, which will determine the long-term durability of endografts in the aortic arch. However, endovascular repair represents an important opportunity for improving outcomes in high-risk patients with complex aneurysms and dissections of the aortic arch.

Comparison of techniques for left subclavian artery preservation during thoracic endovascular aortic repair: A systematic review and single-arm meta-analysis of both endovascular and surgical revascularization

Background

Currently, the optimal technique to revascularize the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR) remains controversial. Our study seeks to characterize early and late clinical results and to assess the advantages and disadvantages of endovascular vs. surgical strategies for the preservation of LSA.

Methods

PubMed, Embase and Cochrane Library searches were conducted under the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analyses) standards. Only literature published after January 1994 was included. Studies reporting on endovascular revascularization (ER), surgical revascularization (SR) for LSA preservation were included. 30-day mortality and morbidity rates, restenosis rates, and rates of early and late reintervention are measured as outcomes.

Results

A total of 28 studies involving 2,759 patients were reviewed. All articles were retrospective in design. Single-arm analysis found no significant statistical differences in ER vs. SR in terms of 30-day mortality and perioperative complication rates. The mean follow-up time for the ER cohort was 12.9 months and for the SR cohort was 26.6 months, respectively. Subgroup analysis revealed a higher risk of perioperative stroke (4.2%) and endoleaks (14.2%) with the chimney technique compared to the fenestrated and single-branched stent approaches. Analysis of the double-arm studies did not yield statistically significant results.

Conclusion

Both ER and SR are safe and feasible in the preservation of LSA while achieving an adequate proximal landing zone. Among ER strategies, the chimney technique may presents a greater risk of neurological complications and endoleaks, while the single-branched stent grafts demonstrate the lowest complication rate, and the fenestration method for revascularization lies in an intermediate position. Given that the data quality of the included studies were relatively not satisfactory, more randomized controlled trials (RCTs) are needed to provide convincing evidence for optimal approaches to LSA revascularization in the future.

Single-center experience with a unibody single-branched stent graft for zone 2 thoracic endovascular aortic repair

To provide an adequate proximal landing zone, left subclavian artery (LSA) reconstruction has become an important part of thoracic endovascular aortic repair (TEVAR). This study evaluates the short and medium term efficacy of a novel unibody single-branched stent graft for zone 2 TEVAR. Fifty-two patients (mean age, 56 ± 10.9 years; 42 men) with distal aortic arch lesions requiring LSA reconstruction received unibody single-branched stents from September 2019 to March 2021. Computed tomography angiography was performed 6, 12, and 24 months after surgery to observe stent morphology, branch patency, endoleaks, stent-related adverse events, and changes in the diameter of true and false lumens. All stents were deployed adequately, and the technical success rate was 100%. The mean operation time was 121.8 ± 47.0 min. The mean postoperative hospital stay was 6.2 ± 3.7 days, and the mean follow-up was 16.8 ± 5.2 months (range, 12–24 months). During follow-up, there were no deaths and complications such as stent displacement or fracture, stenosis, fracture, occlusion, and type Ia endoleaks. The patency rate of the branched segment was 100%. In 42 patients with aortic dissection (AD), the true lumen diameter of the aortic isthmus was 29.4 ± 2.9 mm after surgery, significantly larger than before surgery (20.6 ± 5.4 mm, P < 0.05). Postoperative aortic isthmus false lumen diameter was significantly smaller than that before operation (6.1 ± 5.2 mm vs. 16.0 ± 7.6 mm, P < 0.05). The new unibody single-branched stent for zone 2 TEVAR is safe and accurate, and its efficacy is good in the short and medium term.

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.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

OBJECTIVE

Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes.

METHODS

We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected.

RESULTS

Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality.

CONCLUSIONS

Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

Mid-term Comparison of One-Piece Branched Stent-Graft and Chimney Technique Treating Aortic Arch Pathologies

PURPOSE

We compared the mid-term outcomes of a one-piece branched stent-graft with the chimney technique in the treatment of aortic arch pathologies.

METHODS

Between August 2012 and December 2017, a retrospective analysis of 279 patients with thoracic aortic dissection (TAD) or aneurysm (TAA) who underwent thoracic endovascular aortic repair with b-TEVAR (n = 69, 58 TAD and 11 TAA) or c-TEVAR (n = 210, 151 TAD and 59 TAA) was performed.

RESULTS

Forty-five double-chimney for the left subclavian artery (LSA) and left common carotid artery LCCA and 165 single-chimney for the LSA were performed in chimney-TEVAR (c-TEVAR) and 69 branched-TEVAR (b-TEVAR) with 36 single-branched stent-grafts and 33 branched stent-grafts combined with fenestration technique. The c-TEVAR group experienced more in-hospital complications than the b-TEVAR group (19.5 vs. 7.2%, p = 0.017), primarily because the c-TEVAR group experienced more in-hospital cerebral ischemia events (6.2 vs. 0%, p = 0.043) and intra-operative type I endoleaks (31.9 vs. 5.8%, p < 0.01). There were significantly more follow-up type I endoleaks (21.9 vs. 4.3%, p = 0.002), cerebral ischemia events (11.0 vs. 2.9%, p = 0.042), and re-interventions (12.9 vs. 4.3%, p = 0.048) in the c-TEVAR group than in the b-TEVAR group. However, follow-up mortality was not significantly different between the c-TEVAR and b-TEVAR groups (5.2 vs. 2.9%, p = 0.638).

CONCLUSION

In patients with aortic pathologies involving the arch branches, customized b-TEVAR may result in fewer cerebral ischemia events and endoleaks than c-TEVAR. However, c-TEVAR should be considered an off-the-shelf treatment option for patients in need of emergency treatment.

LEVEL OF EVIDENCE

Level 4, Case Series.

A Novel Solution for Distal Dilation of Chronic Dissection After Repair Involving Visceral Branches: The Road Block Strategy

Aim

Notwithstanding that unprecedented endovascular progress has been achieved in recent years, it remains unclear what is the best strategy to preserve the blood perfusion of abdominal visceral arteries and promote positive aortic remodeling in patients with distal dilatation of chronic aortic dissection in abdominal visceral part (CADAV) after aortic repair. The present study developed a Road Block Strategy (RBS) to solve this conundrum.

Methods and Results

This prospective single-center clinical study included patients suffering from symptomatic distal dilatation of CADAV after aortic repair treated with RBS from January 2015 to December 2019 and followed up regularly for at least 2 years. Stent grafts were implanted first to cover distal tears and expand the true lumen. Device embolization was performed to induce proximal and distal segmental false lumen thrombosis (FLT) apart from the level of the ostia of vital branches. Successful RBS was performed in 13 patients. Significant differences were found in maximum true lumen diameter (p < 0.05), blood flow area in false lumen (FL) (p < 0.001), and the ratio of blood lumen to FL area (p < 0.05) between the pre-procedure and the latest follow-up results. No aortic rupture, vital branches occlusion, thoracic and abdominal pain, or death occurred during hospitalization and follow-up.

Conclusions

Our findings suggest that RBS is feasible in treating distal dilatation of chronic aortic dissection after prior proximal repair, inducing false lumen thrombosis, preventing deterioration of aortic dissection, and maintaining the patency of abdominal visceral arteries.

Parallel grafts and physician modified endografts for endovascular repair of the aortic arch

Aortic arch aneurysms are a challenging clinical problem especially in high-risk patients. Open aortic arch replacement, even in the best of centers, carries significant risk of stroke or death in this high-risk population. Many high-risk patients are deemed inoperable and not offered repair. Branched and fenestrated thoracic endografts are currently undergoing clinical trials in the United States but are not yet commercially available. Many elderly and frail patients have significant brachiocephalic occlusive disease or anatomy excluding them for consideration for such clinical trials. These patients also present with acute aortic syndromes requiring urgent or emergent repair and are unable to participate in clinical trials due to the time required to have such devices available. Alternative endovascular therapies, including parallel stent grafts (including Chimneys, Snorkels and Periscopes) and physician modified thoracic endografts, have been used to treat such high-risk patients combined with commercially available thoracic endovascular aneurysm repair (TEVAR) devices. This paper aims to review the techniques and current reported outcomes from parallel stent grafts and physician modified devices used to treat high risk patients undergoing repair for aortic arch pathologies.

Short-term results of chimney stent revascularization of left subclavian artery and Zone 2 thoracic endovascular aortic repair for patients with aortic dissection or transection

Background

In this study, we present the short-term results of revascularization of left subclavian artery with the chimney technique in patients with aortic dissection or transection who underwent Zone 2 thoracic endovascular aortic repair.

Methods

A total of 11 patients (6 males, 5 females; mean age: 56.4±11.5 years; range, 38 to 76 years) who underwent Zone 2 thoracic endovascular aortic repair procedure and left subclavian artery revascularization with the chimney technique between April 2017 and January 2020 in our clinic were retrospectively analyzed. All patients were followed at one, three, six months and one year with computed tomography angiography.

Results

The mean follow-up was 19.7±14.5 (range, 6.3 to 45.8) months. Endoleak occurred in one (9%) patient and gutter leak occurred in three (27%) patients. The mean endoleak-free (including gutter leak) time was 19.9±5.4 (95% confidence interval: 9.36-30.34) months. No mortality occurred in any of the patients. No occlusion occurred in the chimney grafts.

Conclusion

The chimney revascularization technique is an alternative to other revascularization techniques of the left subclavian artery during thoracic endovascular aortic repair.

Use of Chimney Technique Does Not Improve the Outcome of Endovascular Aneurysm Repair in Patients With a Hyperangulated and Short Proximal Aortic Neck

PURPOSE

We hypothesized that extending the proximal landing zone with the chimney technique could be beneficial in patients with a hyperangulated proximal aortic neck, defined as more > 60 degrees.

MATERIAL AND METHODS

We retrospectively analyzed the outcome of prospectively collected data of patients treated by endovascular aneurysm repair (EVAR) for infrarenal aortic aneurysm with a hyperangulated proximal aortic neck. In all, 104 out of 130 patients were treated without (Group A) and 24 with the chimney endovascular aortic repair (ChEVAR, Group B). Primary outcome was technical and clinical success according to the reporting standards of the Society of Vascular Surgery.

RESULTS

The use of the chimney technique was associated with a significantly longer operation duration (167 vs. 93 min, p < .001), longer fluoroscopy time (44 vs.30 min, p = < .001), and larger amount of contrast medium used (149 vs. 127 ml, p = .03) but did not significantly improve technical (79.2% vs. 87.7%) and clinical success (54.2% vs. 68.9%). Aneurysm-related mortality was higher in group B (8.3% vs. = 0%, p < .001). Type IA endoleak was high in both groups at completion angiography (11.3% in Group A vs. 12.5% in Group B) and at follow-up (10.4% in Group A vs. 4.5% in Group B) without significant difference between the groups.

CONCLUSIONS

Our data did not show a benefit of the primary use of the chimney technique in patients with a hyperangulated and short neck, although more studies are required to support this conclusion. Other strategies or new technologies are required for improving EVAR results in aneurysm patients with severe angulated proximal and short neck.

Pre-Loaded Fenestrated Thoracic Endografts for Distal Aortic Arch Pathologies: Multicentre Retrospective Analysis of Short and Mid Term Outcomes

OBJECTIVE

To determine short and midterm outcomes of a pre-loaded fenestrated thoracic endograft (f-TEVAR) for exclusion of distal aortic arch pathologies.

METHODS

This was a multicentre, retrospective study including consecutive patients from six experienced European vascular centres undergoing f-TEVAR for distal arch pathologies. Primary endpoints included peri-operative mortality and peri-operative stroke and/or spinal cord ischaemia rates. Secondary outcomes were technical success and mid to late events, including death and re-interventions. Statistical analysis was performed with SPSS 26. Mid to late term events were calculated using Kaplan-Meier survival analysis.

RESULTS

One hundred and eight patients were included (mean age 68 ± 11 years, 70% men). A total of 38% (n = 42) had a prior history of aortic dissection, and 24% (n = 26) prior aortic surgery. The mean aneurysm diameter was 59 ± 12 mm and the most frequent indication for treatment was post-dissection aneurysms (n = 42, 39%). Technical success was 99% (n = 107) despite intra-operative wire entanglement occurring in 29% (n = 31). The 30 day mortality rate was 3.7% (n = 4), with a 5.6% major stroke incidence (n = 6) and 3.7% (n = 4) spinal cord ischaemia rate. Three cases of retrograde dissection occurred (two of which were fatal), all in post-type B dissecting aneurysm patients without prior aortic surgery (three of 19, 15.8%). Median follow up was 12 months (range, 1 - 26). Endoleaks were documented during follow up, with 3.5% type Ia (4/104) and 2.9% type Ib (3/104) as a result of persistent false lumen perfusion. The one, two, and three year survivals and freedom from re-intervention rates were 93.2% and 92.1%, 89.1% and 86.3%, and 84.4% and 73%, respectively.

CONCLUSION

This multicentre study shows that treatment of the distal aortic arch by f-TEVAR is feasible, with promising 30 day mortality, stroke, and spinal cord ischaemia rates.

Long-term results of total endovascular repair of arch-involving aortic pathologies using parallel grafts for supra-aortic debranching

OBJECTIVE

We evaluated the long-term morphologic and clinical outcomes after thoracic endovascular aortic repair combined with parallel grafts (PG-TEVAR) for arch-involving aortic pathologies.

METHODS

We performed a retrospective analysis of perioperative and follow-up data of patients who had undergone PG-TEVAR at a single vascular surgery center from November 2010 to April 2018. Patients with prior or simultaneous open chest or cervical debranching procedures or arch repair were excluded. The primary endpoint was freedom from overall PG-TEVAR-related reintervention. The secondary endpoints were parallel graft sealing zone failure (presence of gutter-related type I or Ic endoleak), PG failure (occlusion or reintervention), stroke, and 30-day and overall PG-TEVAR-related and all-cause mortality. Kaplan-Meier curves were used to estimate the freedom from reintervention and survival. Receiver operating characteristics curves were used to find the optimal cutoff to prevent type Ia endoleak-related reintervention.

RESULTS

A total of 33 patients, including 8 women, with a median age of 74 years (interquartile range, 67-79 years) had undergone PG-TEVAR (chimney, periscope, and sandwich in 20, 15, and 13 patients, respectively) with proximal landing in Ishimaru zone 0, 1, or 2 in 4, 5, and 24 patients, respectively. The aortic pathologies included type B aortic dissection (acute and chronic, eight and six, respectively), degenerative aneurysm (n = 10), type Ia endoleak (n = 3), para-anastomotic/patch aneurysm (n = 4), left subclavian artery aneurysm (n = 1), and traumatic rupture (n = 1). The perioperative stroke rate and 30-day mortality was 6% and 9%, respectively. Direct postoperative computed tomography revealed 28 endoleaks (gutter-related type Ia, 12; gutter-related type Ib, 9; type Ia, 2; type Ic, 2; type III, 1; undetermined, 2) in 27 patients. The technical and clinical success rate was 37% and 30%, respectively. The mean follow-up for survival was 48 ± 31 months. The latest radiologic follow-up demonstrated 12 remaining and 1 new endoleak. The early and overall PG sealing zone failure and PG failure was 73% and 36% and 9% and 18%, respectively. The overall PG-TEVAR-related reintervention rate was 33% (n = 11). The estimated freedom from overall PG-TEVAR-related reintervention was 68% at 60 months. The main graft oversizing and length oversizing rates were not significantly associated statistically with the type Ia endoleak-related reintervention rate. The PG-TEVAR-related and all-cause mortality were 18% and 34%, respectively.

CONCLUSIONS

PG-TEVAR for total endovascular repair of arch-involving aortic pathologies resulted in a high rate of type I endoleaks and the need for long-term reintervention. Gutter-related endoleaks might be more frequent than reported and should not be underestimated because they can lead to sac enlargement and reintervention. Frequent radiologic surveillance is mandatory. Further studies comparing PG-TEVAR to other total endovascular alternatives are required to confirm these findings.

Physician-modified Endograft with Left Subclavian Artery Fenestration for Ruptured Type B Aortic Dissection

A 56-year-old male patient was transferred to our institution with acute chest and back pain and deteriorating vital signs for 3 days. Emergent computed tomography angiography (CTA) revealed ruptured type B aortic dissection with large left hemothorax. The dissection extended into the left subclavian artery (LSA). Immediate endovascular aortic repair with LSA coverage to extend the proximal landing zone was planned. Fenestrated thoracic endovascular repair (fTEVAR) was performed using a physician-modified endograft (PMEG) to maintain LSA perfusion. The thoracic endograft was modified on a back table while anesthesia was given, and arterial accesses were acquired. FTEVAR was performed smoothly without any complication. Completion angiogram showed no evidence of endoleak or active bleeding. Chest tube was then placed, and the left lung gradually expanded. Postoperative hospital courses were uneventful. Follow-up CTA showed the thoracic endograft and the LSA stent were in good position, and the rupture thoracic aorta was completely sealed. Chest tube was removed on postoperative day (POD) 7. He was discharged home on POD 20 without any complications. Detailed techniques of PMEG for LSA fenestration are described.

Endovascular repair of the aortic arch: State of the art

BACKGROUND

Open total arch replacement remains the gold standard treatment for aneurysms and dissections involving the aortic arch. However, high-risk surgical candidates may benefit from endovascular techniques to reduce the risk of perioperative mortality and morbidity, especially neurologic complications. Numerous endografts are available for investigational use in the aortic arch as part of investigational device exemption (IDE) programs. Some devices are fenestrated or scalloped, while others are branched, ranging from single branch to triple branch stent-grafts. Furthermore, chimney techniques and in situ fenestration may be utilized in bailout or emergent situations.

RESULTS

Initial results describing outcomes of complete endovascular repair of the aortic arch are encouraging, with current data estimating that technical success ranges from 84.2% to 100%. Moreover, operative mortality may be as high as 13.2%, while neurologic complications also remain common, with stroke rates being as high as 20% and spinal cord ischemia being as high as 3.1%. However, more data are necessary to determine the comparative treatment effect of endovascular stent-grafting of the aortic arch, compared with conventional open and hybrid repairs. Longitudinal follow-up is also lacking, which will determine the long-term durability of endografts in the aortic arch. Nevertheless, endovascular repair represents an important opportunity for improving outcomes in patients with complex and potentially devastating pathologies of the aortic arch.

What are the endovascular options and outcomes for repair of ascending aortic or aortic arch pathology?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'in patients with ascending aortic or aortic arch disease what are the outcomes with endovascular repair in terms of survival, complications and reintervention?' Altogether 585 papers were found using the reported search, of which 9 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We found that the endovascular operative techniques with the greatest evidence were ascending aortic chimney grafts (AACs), branched thoracic endovascular aortic repair (bTEVAR) aortic grafts and fenestrated TEVAR (fTEVAR) aortic grafts. The best evidence available were small case-series or retrospective cohort studies (n < 100), with 1 systematic review, at a short follow-up period (range 0-5 years). Intraoperatively, these techniques have a high technical success rate (84-100%). We found rates of endoleak comparable between AAC (7.4-16%) and bTEVAR/fenestrated TEVAR (11.1-21.4%). Stroke rates are higher in bTEVAR (3.1-42% vs 1-26% in AACs), attributed to more proximal pathology and technically challenging procedures. Following the immediate postoperative period, the 30-day mortality is 0-10.8% and patency is 97-100%. Stroke and reintervention rates remain higher in the bTEVAR group (3.1-42.0% and 0.5-33.3%) compared to the AAC group (1.0-11.1% and 6.7-16.7%). The 3- and 5-year survival ranges from 59% to 90%, but is driven by non-aortic pathology in a high-risk population; 3-year freedom from aortic death is 93-97%. Patency is 97-100% at up to 3 years, conformation and supra-aortic occlusions thereafter remain unknown. We conclude that AACs, bTEVARs and fenestrated TEVARs are safe endovascular options in high-risk elective patients, with results comparable to open or hybrid repair. They remain unverified in acute settings or in patients fit for open intervention.

Open repair versus evar with parallel grafts in patients with juxtarenal abdominal aortic aneurysm excluded from fenestrated endografting

BACKGROUND

We compared the outcomes of open surgical repair (OSR) versus EVAR with parallel graft technique (PG) in patients with juxtarenal abdominal aortic aneurysm (JAAA) excluded from fenestrated endovascular aortic repair (FEVAR) due to clinical, anatomical, technical or manufacturing time reasons.

METHODS

A single-center analysis of consecutive patients who underwent elective and urgent (within 24-48 hours) repair of JAAA from January 2010 to January 2019 was performed. Two groups were compared: patients excluded from FEVAR and respectively treated by OSR or by PG for JAAA. Perioperative clinical, anatomic and operative data were collected in a dedicated database. The endpoints were primary technical success, changes in renal function, early and long-term mortality, freedom from aortic related reinterventions (ARRs) and aortic related mortality (ARM).

RESULTS

118 consecutive patients were treated for JAAA, 32 of them (27.1%) with FEVAR. 86 patients were enrolled in the study (OSR group=61; PG group= 25). The mean age was 77.4 ± 6.5 years for PG group and 71.1 ± 6.7 years for OSR group (p=.0001); the average comorbidity score of the Society for Vascular Surgery was higher for patients treated by PG (10.2 ± 4.8 vs 5.5 ± 0.4, p=.0001), with no differences for hypertension and renal score. After propensity score matching, 42 patients (OSR=27 ; PG=15) without differences in the preoperative risk factors were selected. Conical shape and neck mural thrombus were respectively more represented in the OSR group (95.1% vs 56.0%; 63.9% vs 36.0%). Aortic clamp site was supraceliac for 12 patients (19.7%), suprarenal for 21 (34.4%) and trans-renal for 28 patients (45.9%). In the PG group, 16 patients (64%) were treated with a single renal chimney. Primary technical success was similar in the two groups (100.0% vs 92.0%, p=.08), with an higher rate of procedure achieved by assisted technical success for the PG group after propensity score matching analysis (20.0% vs 0%, p=.04). Deterioration of renal function occurred for both groups of patients, with a significant creatinine increasing 12 months after surgery in the PG group compared with OSR group (1.72 ± 0.66 vs 1.18 ± 0.40, p=.006). Multiple logistic regression shows no independent predictor of peri-operative medical complication among demographics and pre-operative relevant clinical factors between the two cohorts. No difference in terms of early mortality was observed between the groups (1.6 % vs 0%, p=1.00). At 5 years, overall survival was lower for patients treated by PG (53.5% vs 70.2%, p=.007), such as freedom from ARRs (64.6 vs 90.5%, p=.03). Freedom from ARM at 5 years did not show significant differences among the two groups (100% vs 98.4%, p=1.00).

CONCLUSIONS

PG represents a feasible procedure for patients excluded from FEVAR due to clinical, anatomical, technical or device manufacturing time reasons, ensuring low rates of ARM. However, ARRs during the follow-up remain the Achilles heel of this technique. OSR is still the most durable procedure in the endovascular era, allowing the treatment of proximal "hostile necks" with low rates of reoperation and a similar impact on the renal function compared to PG.

Outcomes of chimney/snorkel endovascular repair for symptomatic and ruptured abdominal aortic aneurysms

OBJECTIVE

Symptomatic and ruptured abdominal aortic aneurysms (AAAs) are increasingly being managed with endovascular aneurysm repair (EVAR). We aimed to identify the outcomes of symptomatic and ruptured AAAs that had undergone EVAR with a chimney or snorkel technique (ChEVAR).

METHODS

A retrospective cohort study was performed using the Vascular Quality Initiative registry from March 2013 to July 2019. All patients with symptomatic and ruptured AAAs with a proximal aortic zone of disease from 6 to 9 who had undergone ChEVAR were included. The outcomes were analyzed in accordance with the Society for Vascular Surgery reporting standards for EVAR.

RESULTS

ChEVAR was performed in 77 patients (ruptured, 35 [45.5%]; symptomatic, 42 [54.5%]). The median age was 73.0 years (interquartile range [IQR], 67.0-81.0 years), and 54 patients (70.1%) were men. The median maximum aneurysm diameter was 67.5 mm (IQR, 54.5-83.3 mm). All patients had American Society of Anesthesiologists class ≥III. For the patients with ruptured AAAs, the mean lowest preoperative systolic blood pressure was 95.3 ± 29.3 mm Hg. The fluoroscopy time was 57.4 minutes (IQR, 41.2-79.0 minutes). The proximal aortic zone of disease was zone 6 in 9 (11.7%), zone 7 in 21 (27.3%), zone 8 in 36 (46.8%), and zone 9 in 11 (14.3%) patients. ChEVAR involved more than one vessel in 55 patients (71.4%). No significant difference was found in 30-day mortality between the patients with ruptured vs symptomatic AAAs (11.4% vs 7.1%; P = .695). Reintervention was required for 10 patients (13.0%) at a median of 9 postoperative days, 2 (20.0%) of whom died. Postoperatively, 31 patients (40.3%) had experienced a major complication. A type I endoleak had occurred in nine patients (11.7%), two (22.2%) of whom died. Long-term follow-up data were available for 38 patients (49.4%) at a median of 406.5 days (IQR, 326.8-602.0 days) postoperatively. Of the 18 patients with long-term radiographic data, sac growth was detected in 4 (22.2%). A total of 14 patients had died at a median of 26.5 days (IQR, 3.0-468.5 days).

CONCLUSIONS

ChEVAR for symptomatic and ruptured AAAs can be performed with acceptable rates of morbidity and mortality. Long-term data are needed to determine the durability.

Technical Aspects of Fenestrated Arch TEVAR With Preloaded Fenestration

Fenestrated thoracic endovascular aortic repair (f-TEVAR) has expanded the possibilities of endovascular arch repair, allowing treatment of pathologies involving the aortic arch that require sealing in Ishimaru zones 1 and 2. The growing number of implantations has increased physician experience and helped identify critical procedural points, mainly wire entanglement and device malrotation. Herein we describe a step-by-step approach to a f-TEVAR procedure with the Zenith fenestrated preloaded thoracic endograft, identifying potential pitfalls and suggesting problem-solving solutions.

Endovascular Aortic Repair With Castor Single-Branched Stent-Graft in Treatment of Acute Type B Aortic Syndrome and Aberrant Right Subclavian Artery

OBJECTIVE

In this retrospective study, we presented the results of Castor single-branched stent-graft in a small series of patients with acute type B aortic syndrome and aberrant right subclavian artery (ARSA).

METHODS

Between January 2019 and November 2019, 5 patients were diagnosed with acute type B aortic syndrome and ARSA (4 patients with intramural hematoma and ARSA, 1 patient with type B aortic dissection and ARSA). All the patients underwent thoracic endovascular aortic repair (TEVAR) using Castor single-branched stent-graft. In-hospital and 3-month outcomes were collected.

RESULTS

The mean operative time was 116 ± 20.43 minutes (range 90-145). All the TEVAR procedures were successfully performed without conversion to open surgery (100% success rate). All the ARSAs of the 5 patients were revascularized in situ by Castor single-branched stent-grafts. No deaths and complications were observed in the 3-month follow-up. The maximal diameters of diseased aortas in the 4 patients with IMH decreased 3 months after TEVAR. The false lumen in the graft-covered segment was completely thrombosed in the patient with type B aortic dissection.

CONCLUSIONS

Castor single-branched stent-graft may be a good choice in treatment of acute type B aortic syndrome and aberrant right subclavian artery.

Midterm Outcomes of Zone 0 Antegrade Endograft Implantation During Type I Hybrid Aortic Arch Repair

OBJECTIVE

Type I hybrid arch repair has become popular as a procedure that is less invasive than total arch replacement. The major advantage of this technique is that antegrade endograft implantation can be performed during the procedure, thereby avoiding the complications of introducing the endograft from the groin. The aim of this study was to assess the midterm outcomes of type I hybrid aortic arch repair with antegrade endograft implantation.

METHODS

Thirty consecutive patients who underwent type I hybrid repair with antegrade endograft implantation from 2009 to 2015 were reviewed retrospectively. Patient demographics, and peri-operative and late results were collected from a prospective database and analysed.

RESULTS

Four patients (13%) were female and the median age was 78 years. Median aneurysm size was 64 mm. Six patients (20%) developed stroke, and the 30 day mortality rate was 3%. Two patients suffered aortic dissection at the site of debranching anastomosis. The median follow up was 5.2 years. All aneurysms remained stable or had decreased in size at three years, and 82% were stable at five years. Overall survival was 79% at three years and 71% at five years. The rates of freedom from aorta related death were 86% at three and five years, respectively. During the follow up period, three additional left subclavian artery embolisations and one endograft relining due to type IIIb endoleak were required.

CONCLUSION

Midterm outcomes of type I hybrid aortic arch repair with antegrade endograft implantation for aortic arch aneurysms are reported. Although the incidence of peri-operative stroke was high, late sac behaviour was acceptable.

Early Outcomes of Left Subclavian Artery Revascularization Using Castor Single-Branched Stent-Graft in the Treatment of Type B Aortic Dissection or Intramural Hematoma

Background: More evidence was required to guide the management of left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR). The present study aimed to compare the outcomes of LSA coverage with LSA revascularization. Another purpose of this study was to share our experience of LSA revascularization with castor single-branched stent-graft.

Methods: From January 2016 to December 2019, 134 patients with type B aortic dissection (TBAD) or intramural hematoma (IMH) were enrolled and divided into two groups, the LSA-covered group (n = 61) and the LSA-revascularized group (with castor single-branched stent-graft, n = 73). The results, such as in-hospital and 30-day mortality, stroke, paraplegia, left arm ischemia, operation time, endoleak, were compared between the two groups.

Results: The incidence of 30-day stroke in the LSA-covered group (8.2%) was significantly higher compared with the LSA-revascularized group (0%, P = 0.018). 30-day ischemia of left arm occurred in more patients in the LSA-covered group (11.5%, P = 0.003). No statistical difference was found in the incidences of paraplegia, endoleak, in-hospital mortality, and 30-day mortality.

Conclusions: LSA should be revascularized during TEVAR to reduce the incidences of stroke and left arm ischemia. Castor single-branched stent-graft was feasible and safe for treating TBAD or IMH.

Complications and Management of the Thoracic Endovascular Aortic Repair

Endovascular treatment in thoracic aortic diseases has increased in use exponentially since Dake and colleagues first described the use of a home-made transluminal endovascular graft on 13 patients with descending thoracic aortic aneurysm at Stanford University in the early 1990s. Thoracic endovascular aneurysm repair (TEVAR) was initially developed for therapy in patients deemed unfit for open surgery. Innovations in endograft engineering design and popularization of endovascular techniques have transformed TEVAR to the predominant treatment choice in elective thoracic aortic repair. The number of TEVARs performed in the United States increased by 600% from 1998 to 2007, while the total number of thoracic aortic repairs increased by 60%. As larger multicenter trials and meta-analysis studies in the 2000s demonstrate the significant decrease in perioperative morbidity and mortality of TEVAR over open repair, TEVAR became incorporated into standard guidelines. The 2010 American consensus guidelines recommend TEVAR to be “strongly considered” when feasible for patients with degenerative or traumatic aneurysms of the descending thoracic aorta exceeding 5.5 cm, saccular aneurysms, or postoperative pseudoaneurysms. Nowadays, TEVAR is the predominant treatment for degenerative and traumatic descending thoracic aortic aneurysm repair. Although TEVAR has been shown to have decreased early morbidity and mortality compared with open surgical repair, endovascular manipulation of a diseased aorta with endovascular devices continues to have significant risks. Despite continued advancement in endovascular technique and devices since the first prospective trial examined the complications associated with TEVAR, common complications, two decades later, still include stroke, spinal cord ischemia, device failure, unintentional great vessel coverage, access site complications, and renal injury. In this article, we review common TEVAR complications with some corresponding radiographic imaging and their management.

Trends and outcomes of thoracic endovascular aortic repair with open concomitant cervical debranching

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has become the most common surgical procedure for treatment of descending thoracic aortic pathology. Cervical debranching in the form of carotid-subclavian bypass or transposition (CSBT) and carotid-carotid bypass (CCB) has enabled the use of TEVAR for the treatment of more complex anatomy involving the arch. The present study examined the effects of concomitant cervical bypass on the perioperative outcomes of TEVAR.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program files (2005-2017) were reviewed. Using the Current Procedural Terminology codes, all patients who had undergone TEVAR were identified and were divided into three groups: TEVAR, TEVAR with one bypass (CSBT or CCB), and TEVAR with two bypasses (CSBT and CCB). The patient characteristics and perioperative outcomes of the three groups were compared. Multivariable analysis was performed to determine the factors associated with mortality.

RESULTS

A total of 3281 patients had undergone TEVAR and 10% had also undergone one or more debranching procedure (one bypass, 9%; two bypasses, 1%). The frequency of debranching had increased from 3.4% to 10.9% (P = .01) during the study period. Significant differences were found among the three groups in age, sex, smoking history, urgency of surgery, and anesthesia technique. The patients who had undergone TEVAR with cervical debranching had had significantly greater morbidity, longer operating times, and longer hospital stays compared with those who had undergone TEVAR alone. The mortality of TEVAR with two bypasses (22.6%) was significantly greater than that of TEVAR alone (7.5%) and TEVAR with one bypass (6.8%; P < .01). The total morbidity (30.9% vs 35.1% vs 67.7%; P < .001) and stroke rate (3% vs 7.5% vs 12.9%; P < .0001) increased with the increasing number of bypasses. A subgroup analysis of patients who had undergone TEVAR with one bypass showed no significant differences in mortality between TEVAR plus CSBT (6.6%) vs TEVAR plus CCB (8.8%; P = .63). Multivariable analysis showed that TEVAR with two bypasses was associated with significantly increased mortality compared with TEVAR alone (odds ratio [OR], 4.33; 95% confidence interval [CI], 1.75-10.73) and TEVAR with one bypass (OR, 3.44; 95% CI, 1.24-9.51). Older age (OR, 1.74; 95% CI, 1.42-2.13), dependent functional status (OR, 1.48; 1.00-2.19), dialysis (OR, 2.61; 95% CI, 1.57-4.33), and emergent status (OR, 3.66; 95% CI, 2.73-4.90) were also associated with mortality.

CONCLUSIONS

TEVAR with concomitant cervical debranching has been increasingly used to treat complex aortic pathology but is associated with significantly worse outcomes than TEVAR alone. As advanced endovascular technology to treat the aortic arch emerges, the outcomes of open surgical debranching in the present study constitute an important benchmark for comparison.

Current assessment and management of endoleaks after advanced EVAR: new devices, new endoleaks?

INTRODUCTION

In recent years there has been an increasing application of advanced EVAR techniques to tackle complex clinical and anatomical scenarios. In a bid to overcome the limitations of the traditional stent-grafts, newer EVAR endografts and techniques have been developed and introduced into clinical practice, permitting endovascular management of difficult infrarenal, juxta-renal and thoracoabdominal aneurysms for which previously there was no endovascular solution. As a consequence, we are now confronted with unique patterns of endoleak requiring customized clinical-radiological assessment and treatment. Despite the increasing body of evidence regarding new EVAR techniques and related endoleaks, current guidelines do not specifically address these issues.

OBJECTIVES

Our review aims to assess risk factors, development, and management strategies of these endoleaks, in the most recent infrarenal EVAR devices and in more complex fenestrated EVAR (FEVAR) and Chimney EVAR (Ch-EVAR).

EXPERT OPINION

Most new devices have demonstrated types of endoleaks that need specific imaging and treatment, as in EVAS, FEVAR, and ChEVAR. Knowledge of specific stent-graft characteristics and the nature of endoleaks associated with the various procedures facilitates the application of relevant useful imaging. In addition, it should aid development of a customized and practically relevant approach to patient management during intervention and follow-up.

Endovascular Aortic Arch Reconstruction with Parallel Grafts: A Dilemma of Excessive Endograft Oversizing

Background

Preservation of supra-aortic branches in thoracic endovascular aortic repair plays a role in associated neurological outcomes, and the strategy varies.

Objectives

This study aimed to evaluate the safety and efficacy of a parallel graft technique to reconstruct the aortic arch.

Methods

From August 2014 to July 2018, a total of 25 patients with thoracic aortic pathologies requiring arch reconstruction were included. All patients underwent thoracic aortic endovascular repair (TEVAR) with a zone 1 landing aortic stent graft, a chimney graft to preserve the left common carotid artery, and a periscope graft to preserve the left subclavian artery. The associated outcomes and complications were reported.

Results

Eighteen patients presented with aortic dissection, 4 with a thoracic aortic aneurysm, 1 with a penetrating aortic ulcer, 1 with a traumatic aortic injury, and 1 case of re-TEVAR. The technical success rate was 96% (24/25), but the case of immediate failure died of retrograde type A dissection. Over a mean follow-up of 32.33 months, another retrograde type A aortic dissection was detected in 1 month, and a case of early failure (< 1 year) and 3 cases of late failure (> 1 year) whose primary aortic problems recurred were detected.

Conclusions

This study demonstrates a total endovascular approach to preserve supra-aortic branches with a parallel graft technique. However, the dilemma of excessive graft oversizing was disclosed due to the risk of retrograde type A dissections and an unsatisfactory durability in this small series.

Short-term results in canines of novel stent-graft design for chimney technique in TEVAR

Introduction

Parallel stent-stent grafting is a major endovascular technique used to preserve the supra-aortic branches during thoracic endovascular aortic repair (TEVAR) of aortic pathologies involving the aortic arch. The short- and mid-term results of this technique are satisfactory; however, endoleak remains a major concern. Thus, here we designed a new chimney stent-graft to decrease the endoleak rate.

Aim

To testify the feasibility and safety of the new chimney stent-graft system in a canine model.

Material and methods

Six Labrador retrievers were used. Pre-operative data were collected and all operations were performed under general anesthesia. The main and chimney stent-grafts were implanted through the abdominal aorta and left subclavian artery approaches, respectively. Completion digital subtraction angiography (DSA) was performed to confirm the immediate outcomes. All dogs were fed separately for 6 months and sacrificed after aortic angiography. The thoracic aorta and the main and chimney stent-grafts were harvested for histopathologic examination.

Results

No complications were found in follow-up DSA. All branch arteries were patent. Inflammatory responses were observed around the stent-grafts in 3 experimental animals, and slight hyperplasia was observed in the surrounding tissues compared with the normal vessels. There was no mural thrombus in the stent, endothelial cells were noted on the inner surface of the stent, and thrombus was formed in the outer skirt and gutter area. The histopathologic examinations revealed similar results to those of gross necropsy observations.

Conclusions

This study demonstrated the feasibility and safety of the Longuette stent-graft and the first to report a revised stent-graft specific for chimney technique.

Endovascular stent graft repair with chimney technique of an abdominal aortic aneurysm with concomitant horseshoe kidney

A 68-year-old male patient was referred to our clinic for treatment of an infrarenal abdominal aortic aneurysm. Computed tomography angiography revealed a horseshoe kidney overlying the aneurysm. The patient had an accessory renal artery arising from the anterior aspect of the aneurysm. Endovascular aneurysm repair was performed and the accessory renal artery could be revascularized successfully by chimney technique without any morbidity. Postoperative computed tomography angiography revealed complete exclusion of the aneurysm with no endoleak and a patent chimney graft.

The Jailed Coiling Technique for the Treatment of Penetrating Ulcers and Saccular Aneurysms of the Aortic Arch

OBJECTIVE

To evaluate the technical success and short-term outcome of patients with penetrating aortic ulcers (PAUs) and saccular aneurysms (SAs) of the aortic arch treated with the jailed coiling technique.

METHODS

A retrospective review of 9 patients (mean age 70 years, 9 males) treated for PAUs and SAs of the aortic arch between 2018 and 2019 at our institution. Treatment included thoracic endovascular aneurysm repair (TEVAR) with a short (1cm) proximal landing zone, followed by coiling of aneurysm through a jailed extraluminal catheter.

RESULTS

All 9 patients underwent TEVAR followed by jailed coiling of the lumen of the aneurysms. Debranching of supra-aortic vessels was performed in 4 patients in order to create a proximal landing zone of at least 10 mm. Technical success was achieved in all cases. Coils were placed accurately within the aneurysm lumen in all patients. No distal embolization occurred. One patient expired in the perioperative period from a cardiac event. No patient developed spinal cord ischemia or stroke in the perioperative period. Mean follow-up was 10 months (range 3-18). On follow-up imaging, complete thrombosis of the aneurysm lumen was seen in all patients. None experienced enlargement of ulcer dimensions and none required reintervention.

CONCLUSION

PAUs and SAs of the aortic arch with a very short landing zone can be treated successfully by jailed coiling of the aneurysm and TEVAR. The procedure is technically feasible and can be performed with minimal morbidity. Long-term durability of the repair needs to be determined.

Gutter Characteristics and Stent Compression of Self-Expanding vs Balloon-Expandable Chimney Grafts in Juxtarenal Aneurysm Models

Purpose: To assess in silicone juxtarenal aneurysm models the gutter characteristics and compression of different types of chimney graft (CG) configurations. Materials and Methods: Fifty-seven combinations of Excluder C3 or Conformable Excluder stent-grafts (23, 26, and 28.5 mm) were deployed in 2 silicone juxtarenal aneurysm models with 3 types of CGs: Viabahn self-expanding (VSE; 6 and 13 mm) or Viabahn balloon-expandable (VBX; 6, 10, and 12 mm) stent-grafts and Advanta V12 balloon-expandable stent-grafts (ABX; 6 and 12 mm). Setups were divided into 4 groups on the basis of increasing CG and main graft (MG) diameters. Two independent observers assessed gutter size and type as well as CG compression on computed tomography scans using postprocessing software. Results: In the smaller diameter combinations (6-mm CG and 23-, 26-, and 28.5-mm MGs), both VSE (p=0.006 to 0.050) and ABX (p=0.045 to 0.050) showed lower gutter areas and volumes compared with VBX. In turn, the VBX showed a nonsignificant tendency to decreased compression, especially compared to ABX. Use of the Excluder C3 showed a 6-fold increase in type A1 gutters (related to type Ia endoleak) as compared to the Conformable Excluder (p=0.018). Balloon-expandable stent-grafts (both ABX and VBX) showed a 3-fold increase in type A1 gutters in comparison with self-expanding stent-grafts (p=0.008). Conclusion: The current study suggests that use of the Conformable Excluder in combination with VSE chimney grafts is superior to the other tested CG/MG combinations in terms of gutter size, gutter type, and CG compression.