Incidence and prognostic factors related to major adverse cerebrovascular events in patients with complex aortic diseases treated by the chimney technique

Brazilian Angiology and Vascular Surgery Society Guidelines for the treatment of extracranial cerebrovascular disease

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

Latest evidence on chimney endovascular repair of abdominal aortic aneurysms and the renal artery angulation pitfall

This article summarizes the key findings in literature up to date on the endovascular treatment of complex abdominal aortic aneurysms (AAAs) employing the chimney technique. Additionally, an unexplored pitfall is described regarding the target vessel angulation. Although balloon-expandable covered stents present more favorable configuration in downward-oriented target vessels, transverse and upward-oriented target vessels may benefit from other endovascular techniques imploring careful case planning and further investigation on the topic.

Chimney endovascular aneurysm repair (ChEVAR) for hostile neck complex aneurysm

OBJECTIVE

Recent guidelines recognize the role of chimney endovascular aneurysm repair (ChEVAR) in the treatment of complex aortic disorders. The optimal configuration and number of visceral vessels that can be incorporated is still controversial. We aim to review outcomes from a multi-institutional decade-long experience with ChEVAR.

METHODS

Patients undergoing ChEVAR with multiple (≥2) chimney branches were selected from a prospectively maintained database at the two academic university hospitals. All patients were poorly suited for fenestrated or branched endograft repair (F/BEVAR) and deemed poor-risk for open surgery.

RESULTS

Forty-nine multiple ChEVAR were performed in 44 men and 5 women, with complete outcome data at a mean follow-up of 18 months. Overall, 2 patients died during follow-up (4%) with no aneurysm-related mortality and two ruptures after ChEVAR (4.1%) due to a type Ib endoleak from iliac limb pullout and persistent gutter-flow, both repaired with endovascular means. No stroke or spinal cord ischemia was noted during the follow-up period. Reintervention was undertaken in eight patients (16.3%) with five reinterventions for persistent gutter-flow and four chimney graft-associated. Three-vessel ChEVAR was performed in 16 patients, with two-vessel ChEVAR in 33 patients for a total of 114 chimney branches (mean 2.3 chimneys per patient). There were 21 superior mesenteric artery (SMA), 45 right renal, 46 left renal artery (LRA), and two accessory LRA chimneys placed. Antegrade configuration of chimney branches was chosen in 43 patients (88%). There were no significant differences between three-vessel and two-vessel ChEVAR upon univariate analysis in aneurysm size (65.6 vs 60.5 mm; p = 0.059), iliac diameter (7.3 vs 7.1 mm; p = 0.85), or endograft oversizing (30 vs 32.5%; p = 0.43). Three-vessel ChEVAR was associated with a larger aneurysm neck diameter (28.4 vs 25.0 mm; p = 0.021), shorter native infrarenal neck (0.5 vs 3.37 mm; p = 0.002) as well as longer seal zone (36.33 vs 22.67 mm; p = 0.005) compared with two-vessel ChEVAR. At follow-up, there were no significant differences in gutter area between three-vessel and two-vessel ChEVAR (18.9 vs 15.7 mm³; p = 0.73) nor the rate of persistent gutter-flow (12.5 vs 9.1%; p = 0.71).

CONCLUSION

Reintervention to multiple chimney grafts and for persistent gutter-flow is higher compared to single chimneys and demands close surveillance. However, based upon this combined transantlantic experience, we believe multiple ChEVAR provides a reasonable and safe option for complex aortic aneurysm repair when open or custom endografts are not available or indicated based on their Instructions For use, even when triple chimney grafts are required. The optimal configuration for multiple ChEVAR still warrants further study, although theoretical preliminary advantages may exist for a combination of antegrade and retrograde chimneys.

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.

Use of Stainless-Steel, Balloon-Expandable Chimney Grafts Is Durable Though Caution Is Required When Lining Angulated Renal Arteries

Purpose:

To analyze the overall performance of flexible nitinol stents used to line chimney grafts (CGs) during chimney endovascular aneurysm repair (chEVAR) of pararenal pathologies.

Materials and Methods:

A retrospective review was conducted of all 116 elective patients (mean age 74.3±7.2 years; 103 men) who underwent chEVAR with balloon-expandable Advanta V12/iCAST CGs in combination with the Endurant stent-graft between January 2009 and December 2017 at a single center. CG lining with a nitinol stent was electively performed in 43 target vessels of 32 patients. The Kaplan-Meier method was used to estimate the primary outcomes of CG patency and freedom from reintervention (FFR) at the patient level and according to the use of a stent to line the CG. Estimates are reported with the 95% confidence interval (CI). Adjusted odds ratios (ORs) were calculated to identify any confounding effect between the presence/absence of a stent lining or according to the number of CGs.

Results:

The mean radiological follow-up was 27.3 months (range 22.1–32.6). During this time, 8 CGs (4.7%) became occluded, 6 of them were lined with stents. Restoration of patency was possible in 3 of the 4 occluded stents that were associated with symptoms. First-year primary patency estimates were 96.9% (95% CI 92.5% to 100%) for the unlined group vs 77.1% (95% CI 58% to 95.3%; p=0.001) for the lined group, while FFR was 87.6% (95% CI 79.9% to 95.2%) vs 83.4% (95% CI 68.1% to 98.6%; p=0.82), respectively. Lining represented an independent risk factor for CG occlusion (OR 9.9, p=0.006).

Conclusion:

CG lining performed mainly in angulated renal arteries during chEVAR was significantly associated with CG occlusion. These findings highlight the importance of not having the distal part of the CG impinge on the angulated segment of the target vessel.

Simultaneous endovascular treatment of synchronous symptomatic acute type B aortic dissection and large infrarenal aortic aneurysm. Technical tips and case report

INTRODUCTION

Data from the literature suggest that in patients with acute type B aortic dissection (ATBAD), associated with AAA, rupture risk is higher at the confluence tract than isolated lessions. Herein, we report a case of ATBAD and AAA managed with simultaneous intervention.

CASE PRESENTATION

We report a complicated case of a symptomatic patient presenting with a type B aortic dissection and false lumen extension into superior mesenteric artery (SMA) with an infrarenal abdominal aortic aneurysm (AAA). Severe back pain and hypertension were the patient's initial complaints. This patient underwent endovascular repair with a thoracic and infrarenal aortic endograft.

DISCUSSION

AAA rupture has been detected at admission in three-fourths of patients with ATBAD that extended to or involved a coexisting unoperated atherosclerotic aneurysms. Prompt surgical intervention is essential to deal with this dreadful aortic emergency.

CONCLUSION

In our experience a totally endovascular solution to treat a complicated ATBAD plus AAA was a rapid solution with low invasivity, no complication and complete healing of patients.

Parallel graft techniques for urgent complex aortic diseases: Mid-term results of 12 cases

OBJECTIVES

Open repair is still the first choice for thoraco-abdominal and para-renal aortic aneurysms, but surgical treatment is burdened by significant morbidity and mortality, especially in urgent setting. Endovascular treatment by fenestrated or branched endografts is feasible and safe; but in urgent/emergent settings, custom-made endografts are hardly available in due time, and the repair with standard multibranched devices is still debated in cases with complex anatomy. Parallel grafting, on the other hand, which exploits covered stents to preserve patency of the visceral vessels, has been shown as a valuable option and can be performed in urgency, though some concerns still remain regarding its durability and complications. The purpose of this case series is to review the outcomes of all consecutive cases of complex aortic diseases treated with this technique in emergent/urgent setting.

MATERIALS AND METHODS

All cases of endovascular aortic repair of thoraco-abdominal and para-thoraco-abdominal performed in urgency or emergency from 2016 to June 2019 were retrospectively reviewed, recording clinical records, operative technique, primary technical success, and long-term outcomes. Each patient was followed-up by computed tomography angiography three months after the procedure and yearly thereafter.

RESULTS

Twenty consecutive patients (median age: 68, range: 47-89, male/female ratio: 16:4) affected by para-thoraco-abdominal (12) or thoraco-abdominal (8) were treated in urgent or emergent setting by chimney and/or periscope technique. A total number of 37 visceral vessels were stented (29 renal arteries, 1 polar artery of the kidney, 3 superior mesenteric arteries, and 4 coeliac trunks). Primary technical success was 100%, with one perioperative death. One patient died on post-operative month III for unrelated cause. Two type II endoleaks were detected at the first post-operative imaging studies and were managed conservatively. One type IB endoleak was treated by endovascular repair with a custom-made endograft (overall re-intervention rate: 5%). Over a median 22 months follow-up (range: 4-40, interquartile range: 12 months), all stentgrafts were patent.

CONCLUSION

Parallel graft is a feasible and safe option that should be considered in urgent and emergent treatment of para-thoraco-abdominal and thoraco-abdominal, when fenestrated and branched endografts cannot be used.

Multicentre Experience with the Chimney Technique for Abdominal Aortic Aneurysms in French University Hospitals

OBJECTIVE

The chimney technique (ChEVAR) allows for proximal landing zone extension for endovascular repair of complex aortic aneurysms. The aim of the present study was to assess ChEVAR national outcomes in French university hospital centres.

METHODS

All centres were contacted and entered data into a computerised online database on a voluntary basis. Clinical and radiological data were collected on all consecutive ChEVAR patients operated on in 14 centres between 2008 and 2016. Patients were deemed unfit for open repair. Factors associated with early (30 day or in hospital) mortality and type 1 endoleak (Type I EL) were calculated using multivariable analysis.

RESULTS

In total, 201 patients with 343 target vessels were treated. There were 94 juxtarenal (46.8%), 67 pararenal (33.3%), 10 Crawford type IV thoraco-abdominal (5%) aneurysms, and 30 (15.1%) proximal failures of prior repairs. The pre-operative diameter was 66.8 ± 16.7 mm and 28 (13.9%) ChEVAR were performed as an emergency, including six (2.9%) ruptures. There were 23 (11.7%) unplanned intra-operative procedures, mainly related to access issues. The rate of early deaths was 11.4% (n = 23). The elective mortality rate was 9.8% (n = 17). Nine patients (4.5%) presented with a stroke. The rate of early proximal Type I EL was 11.9%. Survival was 84.6%, 79.4%, 73.9%, 71.1% at 6, 12, 18, and 24 months, respectively. The primary patency of chimney stents was 97.4%, 96.7%, 95.2%, and 93.3% at 6, 12, 18, and 24 months, respectively. Performing unplanned intra-operative procedures (OR 3.7, 95% CI 1.3-10.9) was identified as the only independent predictor of post-operative death. A ChEVAR for juxtarenal aneurysm was independently associated with fewer post-operative Type I ELs (OR 0.17, 95% CI 0.05-0.58).

CONCLUSION

In this large national ChEVAR series, early results were concerning. The reasons may lie in heterogeneous practices between centres and ChEVAR use outside of current recommendations regarding oversizing rates, endograft types, and sealing zones. Future research should focus on improvements in pre-operative planning and intra-operative technical aspects.

The role of fEVAR, chEVAR and open repair in treatment of juxtarenal aneurysms: a systematic review

INTRODUCTION

Open repair (OR), fenestrated endovascular aneurysm repair (fEVAR) and endovascular exclusion using parallel graft (chEVAR) are complementary procedures used for treatment of juxtarenal abdominal aortic aneurysm (jrAAA). The aim of our study was to assess available literature and analyze dispersion of OR, fEVAR and chEVAR procedures among reported papers related to treatment of jrAAA.

EVIDENCE ACQUISITION

The PubMed database was systematically searched using predefined strategy and key words related to treatment of jrAAA on September 28th, 2019. Studies were assessed for eligibility using the inclusion and exclusion criteria with at least five patients treated with at least one of the procedures while systematic reviews, meta-analysis, reviews, comments, editorials and letters were excluded as well as studies without clear classification of the location of the aneurysm, studies not specifying the number of patients treated with each of the techniques or not discriminated between aortic pathologies (juxtarenal, paravisceral and thoracoabdominal), hybrid procedures, endoanchors or with branched stent-graft.

EVIDENCE SYNTHESIS

Overall, 1533 papers were identified while papers that met inclusion criteria were either representing experience of single institution (87 papers) or from multicenter studies (6 papers), national or international registries (18 papers). In the period between January 1977 and December 2017, treatment of 5664 patients with jrAAA was reported in 87 papers as a single institution report. Out of them 2531 (45%) were treated with OR, 2592 (46%) with fEVAR and 541 (9%) with chEVAR. Out of 29 institutions reporting OR, there were 11 (37.9%) with more than 100 treated patients while 21 (41.1%) out of 51 institutions that reported more than 50 jrAAA treated with fEVAR. Only four institutions reported results of all three treatment modalities.

CONCLUSIONS

Based on the results reported in the literature, regardless of its complexity and costs, fEVAR for jrAAA has been accepted in substantial number of hospitals worldwide, while number of reported procedures is reaching OR.

Cerebrovascular Complications After Upper Extremity Access for Complex Aortic Interventions: A Systematic Review and Meta-Analysis

PURPOSE

The purpose of this study was to review the risk of developing cerebrovascular complications from upper extremity access during endovascular treatment of complex aortic aneurysms.

METHODS

A systematic review and meta-analysis were conducted according to the PRISMA guideline. An electronic search of the public domains Medline (PubMed), Embase (Ovid), Web of Science and Cochrane Library was performed to identify studies related to the treatment of aortic aneurysms involving upper extremity access. Meta-analysis was used to compare the rate of cerebrovascular event after left, right and bilateral upper extremity access. Results are presented as relative risk (RR) and 95% confidence intervals (CIs).

RESULTS

Thirteen studies including 1276 patients with complex endovascular treatment of aortic aneurysms using upper extremity access were included in the systematic review. Left upper extremity access (UEA) was used in 1028 procedures, right access in 148 and bilateral access in 100 procedures. The rate of cerebrovascular complications for patients treated through left UEA was 1.7%, through right UEA 4% and through bilateral UEA 5%. In the meta-analysis, we included seven studies involving 645 patients treated with a left upper extremity access, 87 patients through a right and 100 patients through a bilateral upper extremity access. Patients, who underwent right-sided (RR 5.01, 95% CI 1.51-16.58, P = 0.008) or bilateral UEA (RR 4.57, 95% CI 1.23-17.04, P = 0.02), had a significantly increased risk of cerebrovascular events compared to those who had a left-sided approach.

CONCLUSION

Left upper extremity access is associated with a significantly lower rate of cerebrovascular complications as compared to right or bilateral upper extremity access.

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.

FEVAR/BEVAR have limitations and do not always represent the preferred option for juxtarenal reconstruction

Following the definition given by the recent ESVS guidelines, juxtarenal abdominal aortic aneurysm (JAAA) is defined as an aneurysm extending up to but not involving the renal arteries, necessitating suprarenal aortic clamping for open surgery, i.e. a short neck (<10 mm). JAAA repair always represents a challenge intervention, either by open or endovascular means, mostly related to the renal arteries involvement. Concerning endovascular repair, different options can be considered. Among them, fenestrated endografts (FEVAR) should be considered as a first option1, due to their reported safety and efficacy. However, when the anatomy is not favorable or when FEVAR devices are not available in an emergency setting for instance, other alternatives can be considered like parallel graft or chimney technique (ChEVAR). Do nothing is the last alternative when medical and anatomical circumstances are absolutely poor. In the following pages, we will review the limitations of FEVAR and branched endografts, the better indications and anatomical conditions for a successful repair with ChEVAR technique and its current clinical results reported in the literature.

The use of a low-profile stent graft with a polymer ring sealing technology combined with bare renal stent (vent technique) in patients with juxtarenal aneurysm not eligible for open surgery and fenestrated endograft

OBJECTIVE

In cases of juxtarenal abdominal aortic aneurysm (jAAA), endovascular aneurysm repair (EVAR) involves the use of custom-made fenestrated stent grafts, which usually need large-diameter access vessels, superior costs, and a certain time between graft planning and delivery. We report our preliminary experience using the bare renal stent technique (called vent) in combination with the ultralow-profile stent graft Ovation (Endologix, Irvine, Calif) to seal jAAAs in patients evaluated to be unfit for open surgery and not suitable for fenestrated endograft.

METHODS

A single-center retrospective review of jAAAs treated by Ovation vent technique from January 2015 to December 2018 was conduced. The vent procedure consisted of a modified, off-label deployment of the sealing ring of the ultralow-profile Ovation stent graft close to renal orifices in combination with short bare-metal stents. The exclusion criterion was a diameter >31 mm at the level of the lowest renal artery. Early technical and clinical results, estimated midterm survival, renal artery patency, freedom from type IA endoleak, freedom from reintervention, and freedom from neck enlargement (>2 mm) were reported.

RESULTS

Overall, 38 patients had jAAA and were considered unfit for open repair and not eligible for fenestrated EVAR. The proximal neck was <5 mm in all cases (mean, 3.3 ± 1.2 mm). Vent renal stents were implanted bilaterally in 16 patients. Primary technical success was 94.7% (36/38), with satisfactory cannulation of all renal arteries and sealing of the aneurysm in all but two cases because of type IA endoleaks that were treated immediately with success. Primary clinical success at 1 month was 100%. During a median follow-up period of 22.4 ± 3.6 months (range, 1-46 months), no abdominal aortic aneurysm-related deaths occurred, and no patient was lost to follow-up. The survival curve at 1 year and 2 years was, respectively, 96.4% and 91.6% (standard error, 0.57%). There were no cases of neck dilation or endograft migration. Freedom from reintervention at 12 months and 24 months was 100% and 89.5%, respectively (standard error, 0.7%); freedom from type IA endoleak was 100% and patency of the renal artery was 100% at 2 years.

CONCLUSIONS

The described technique includes the use of a low-profile stent graft with a polymer ring sealing technology combined with bare renal stents that are not competing for the same room. This early experience shows that the vent technique is safe and feasible and increases the range of treatment of those patients with jAAA who are unfit for open repair and for fenestrated EVAR because of several anatomic constraints.