The PROTAGORAS 2.0 Study to Identify Sizing and Planning Predictors for Optimal Outcomes in Abdominal Chimney Endovascular Procedures

The Effect of EndoAnchors on Aneurysm Sac Regression for Patients Treated With Infrarenal Endovascular Repair With Hostile Neck Anatomies: A Propensity Scored Analysis

PURPOSE

To analyze sac evolution patterns in matched patients with hostile neck anatomy (HNA) treated with standard endovascular aneurysm repair (sEVAR) and endosutured aneurysm repair (ESAR).

METHODS

Observational retrospective study using prospectively collected data between June 2010 and December 2019. ESAR group data were extracted from the primary arm of the PERU registry with an assigned identifier (NCT04100499) at 8 centers and those from the sEVAR came from 4 centers. Suitability for inclusion required: no proximal endograft adjuncts (besides EndoAnchor use), ≤15 mm neck length and minimum of 12-months follow-up imaging. Bubble-shaped neck (noncylindrical short neck with discontinuous seal) aspect was analyzed. Both groups were analyzed using propensity score matching (PSM) for aortic neck length, width, angulation, and device fixation type. Main outcome assessed was sac evolution patterns (sac expansion and regression were defined as >5mm increase or decrease, of the maximum sac diameter respectively; all AAAs within this ±5 mm range in diameter change were considered stable) and secondary outcomes were type-Ia endoleaks; other endoleaks and mortality. A power analysis calculation >80% was confirmed for sac regression evaluation.

RESULTS

After exclusions, PSM resulted in 96 ESAR and 96 sEVAR patients. Mean imaging follow-up (months) was 44.4±21.3 versus 43.0±19.6 (p=0.643), respectively. The overall number of patients achieving sac regression was higher in the ESAR group (n=57, 59.4% vs n=31, 32.3%; p<0.001) and the cumulative sac regression achieved at 5 years was 65% versus 38% (p=0.003) in favor of the ESAR group. There were no statistically significant differences in type-Ia endoleak and/or other endoleaks. Univariate analysis for sac regression patients in the sEVAR and ESAR group individually showed the bubble-shape neck as a predictor of sac regression failure. There were no statistical differences in overall and aneurysm-related mortality.

CONCLUSION

Endosutured aneurysm repair provided improved rates of sac regression for patients with AAA and HNA when compared with sEVAR at midterm and up to 5 years, despite similar rates of type-Ia endoleaks, and the need to consider some important limitations. The presence of bubble-shaped neck was a predictor of sac regression failure for both groups equally.

CLINICAL IMPACT

The use of EndoAnchors aids and improves EVAR treatment in hostile neck anatomies by an increased rate of sac regression when compared to EVAR treatment alone in up to 5 year analysis. Moreover, a trend to reduced number of type Ia endoleaks is also achieved, although not significant in the present study. This data, adds to current and growing evidence on the usefulness of EndoAnchors for AAA endovascular treatment.

Renal intravascular shockwave lithotripsy in complex mono Ch-EVAR

BACKGROUND

Our objective is to present the Peripheral Intravascular Lithotripsy (IVL) System in the treatment of calcific renal artery stenosis (RAS) during Chimney Endovascular Aneurysm Repair (Ch-EVAR). The Ch-EVAR technique is a bail out procedure in treating aortic aneurysms with challenging anatomy regarding the proximal sealing zone. RAS typically involves varying degrees of calcification, and final treatment can be fraught with risk of vessel's damages and suboptimal results, particularly when renal angioplasty represents the only feasible course of action in Ch-EVAR.

METHOD

We present a case of a patient with a complex juxtarenal abdominal aortic aneurysm and a pre-obstructive chalky stenosis of the right renal artery who underwent mono ChEVAR associated to visceral Intravascular Lithotripsy shockwave angioplasty.

CONCLUSION

IVL is an attractive modality for the treatment of challenging, heavily calcified renal arteries that combines the calcium-disrupting capability of lithotripsy with the familiarity of balloon catheters to facilitate proper stent deployment.

RESULT

We propose the IVL system as an additional tool in the vascular surgeon's armamentarium not only to obtain large-bore access to enable Transaortic Valve Replacement (TAVR) and EVAR but also to perform angioplasty of severely calcified visceral arteries during Ch-EVAR.

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.

Protagoras 3.0: feasibility of current fenestrated endografts and chimney technique for complex abdominal aortic aneurysms

BACKGROUND

The aim of this study was to evaluate the anatomical feasibility of current available fenestrated endografts (FEVAR) and on-label chimney technique (EnChEVAR) in patients with complex abdominal aortic aneurysms (C-AAA).

METHODS

Feasibility of EnChEVAR (Endurant II/IIS CE-marked [Medtronic]) and 4 types of FEVAR (Zenith Fenestrated CE-marked, Zenith Fenestrated Low-Profile [LP] custom-made device [CMD] [Cook Medical], Fenestrated Anaconda LoPro90 CMD, Fenestrated Treo CMD [Terumo Aortic]) was assessed according to the manufacturer's instructions for use. Computed tomography angiograms of patients with C-AAA previously included in the Protagoras 2.0 study were retrospectively reviewed. The aortic coverage was ideally planned to involve a maximum of two chimney grafts or fenestrations.

RESULTS

Iliac access and aortic neck of 73 C-AAAs were analyzed. The overall feasibility was significantly different between EnChEVAR (33%) and FEVAR (Zenith Fenestrated 15%, Zenith Fenestrated LP 15%, Fenestrated Anaconda LoPro90 45%, Fenestrated Treo 48%). The iliac access feasibility was significantly lower for Zenith Fenestrated with standard profile compared to all other grafts. The aortic neck feasibility was significantly higher for EnChEVAR and both Terumo Aortic fenestrated stent grafts, compared to both Cook Medical grafts. The treatment using any of the three current available fenestrated grafts with lower profile (Zenith Fenestrated LP, Fenestrated Anaconda LoPro90, Fenestrated Treo) would have been feasible in 71% of the cases.

CONCLUSIONS

Most of the patients treated by ChEVAR would have not been treated by first generation fenestrated stent graft. The current available fenestrated endografts, with lower profile and suitable also for angulated necks, increase the anatomical feasibility.

Early multicentric outcomes of the on-label and CE-marked combination of the Endurant with the Radiant chimney graft for the chimney endovascular aortic repair (EnChEVAR): The LaMuR Registry

BACKGROUND

The aim of this study was to evaluate the early results of the CE-marked standardized device combination consisting of Endurant and the Radiant chimney graft (En-ChEVAR) for the treatment of juxtarenal aortic aneurysms.

METHODS

We analyzed multicentric non-industry sponsored case series evaluating the EnChEVAR technique for patients treated between December 2022 and February 2024. Clinical, perioperative procedure-related and radiological data were collected. The primary outcome measure was the freedom of a type Ia gutter-related endoleak at postoperative computed tomography angiography (CTA). Secondary outcome measures included early type Ia endoleak-related reinterventions, target vessel complications including dissection or loss of target vessel, major adverse events, and mortality. Continuous variables were presented as median (interquartile range [IQR]) and categorical variables as count and percentage.

RESULTS

Ten patients were included in the present study. Eight (80%) were males, in nine cases a single chimney was implanted, and the other one was a double chimney graft placement. The treated aneurysms had an infrarenal neck length of 3.4 (1.2) mm. The rate of main body oversizing was 30%. The new neck length after chimney graft placement was 18 (3) mm. The median procedural time was 130 (17) mm, contrast medium use was 109 (26) mL, radiation time was 45 (12) min. The technical success was 100%. No type Ia endoleak was detected at the postoperative CTA. There were no target vessel issues. No major adverse events or death were observed.

CONCLUSIONS

First reported cohort of patients treated with EnChEVAR demonstrated reproducible clinical and procedural outcomes within the 3 vascular centers with total exclusion of the aneurysms, patent renal arteries, and no evidence of gutter-related type IA endoleak. Further evidence with larger sample size of treated patients and longer follow-up are needed.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Incidence of endoleak type IA in patients undergoing chimney endovascular aortic repair (ChEVAR) vs. standard endovascular repair

Objectives

Almost half of endovascular aortic aneurysm repair (EVAR) procedures are performed in hostile anatomy, increasing the risk of procedure related complications such as type IA endoleaks, which may be prevented with the chimney technique in EVAR (ChEVAR). Our aim is to describe the differential characteristics between EVAR in favorable anatomy and ChEVAR in hostile necks.

Materials and methods

A cohort of patients with infrarenal abdominal aortic aneurysms (AAA) that were treated with EVAR or ChEVAR were included. The primary outcome was the incidence of type IA endoleak. Secondary outcomes were the rate of chimney occlusion, reintervention, migration, rupture, acute limb ischemia, sac growth, and aneurysm-related mortality during the follow-up period.

Results

. With a median follow-up of 11.5 months, 79 patients were treated with EVAR and 21 with ChEVAR. The overall age was 76.49 ± 7.32 years old, and 82% were male. The ChEVAR cohort had a higher prevalence of tobacco use than the EVAR cohort (38.1% vs. 17.7%, p = 0.041), and a shorter neck (7.88 mm ± 5.73 vs 36.28 mm ± 13.73, p<0.001). There were no differences in type IA endoleak incidence between the groups (a single endoleak type IA in the EVAR group, p = 0.309). One patient experienced an asymptomatic chimney occlusion in the ChEVAR group, and another patient required a reintervention due to chimney occlusion. Sac regression and reinterventions were not different between groups. There were no migration, rupture, acute limb ischemia, or aneurysm-related mortality events.

Conclusions

. In patients with abdominal aortic aneurysms, ChEVAR in hostile necks had similar event rates to EVAR in favorable necks.

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.

Anatomical feasibility of the current endovascular solutions for Juxtarenal aortic abdominal aneurysm repair

PURPOSE

Endovascular repair of juxta-renal aneurysms (JAAAs) can be achieved by fenestrated endografts (FEVAR), parallel-grafts (CHEVAR) and standard abdominal endografts + endoanchors (ESAR). Aim of this study was to evaluate the incidence of their anatomical feasibility in JAAAs.

MATERIALS AND METHODS

All patients submitted to JAAAs treatment from 2006 to 2019 were retrospectively analyzed, irrelevant of the procedure performed. Juxta-renal aneurysm was defined according with the current ESVS clinical practice guidelines. Preoperative computed tomography angiographies were analyzed to evaluate the anatomical feasibility of: FEVAR (Cook Zenith-platform; CE-marked or custom-made device), CHEVAR (Medtronic Endurant + Atrium Advanta - CE marked combination) and ESAR (Medtronic Endurant + Helifix - CE marked combination) according with the manufactures' instruction for use. The anatomical feasibility of these three endovascular solutions was assessed according with the proximal neck, target visceral vessels (TVVS) and iliac access characteristics.

RESULTS

Ninety-nine cases were considered. There were no cases of frank aortic rupture and in all patients at least one arterial access from above was available. Fenestrated endograft, CHEVAR, and ESAR were anatomically feasible in 93 (94%), 37 (37%), and 27 (27%) cases, respectively (p <. 001). Fenestrated endograft requires design with <3, three and >3 fenestrations in 29 (31%), 33 (36%), and 31 (33%) cases, respectively. Parallel graft technique have required 1 or 2 parallel graft configurations in 12 (12%) and 25 (25%) cases, respectively. Among the 14 cases with aneurysm diameter >70 mm, the anatomical feasibility of FEVAR, CHEVAR, and ESAR was 13(93%), 4(29%), and 4 (29%) cases, respectively (p < .001).

CONCLUSION

Fenestrated endograft is more frequently applicable than CHEVAR and ESAR as endovascular treatment of JAAAs. Since this difference is valid also in aneurysms with diameter >70 mm, the issue of a rapid availability is of paramount importance. The 6% of cases have not any endovascular solution and requires open surgery.

In Vitro Radiological Evaluation of Different Types of Chimney Stents Using a Silicon Flow Model with Adjustable Physiological Simulating Conditions

OBJECTIVE

To evaluate in vitro the performance of in vivo published covered or bare metal chimney stents (ChSs) in combination with the Endurant II abdominal endograft (Medtronic) as the only CE approved main graft (MG) in the treatment of juxtarenal abdominal aortic aneurysms with the chimney endovascular aneurysm repair (chEVAR) technique.

METHODS

Bench top experimental study. A silicon flow model with adjustable physiological simulating conditions and patient based anatomy was used to test nine different MG-ChS combinations: Advanta V12 (Getinge); BeGraft+ (Bentley); VBX (Gore & Associates Inc.); LifeStream (Bard Medical); Dynamic (Biotronik); Absolute Pro (Abbott); double Absolute Pro; Viabahn (Gore) lined with Dynamic; and Viabahn lined with EverFlex (Medtronic). Angiotomography was performed after each implantation. DICOM data were analysed blindly twice per observer by three independent experienced observers. Each blinded evaluation was performed at one month intervals. The main analysed parameters were the area of gutters, MG and ChS maximum compression, and the presence of infolding.

RESULTS

Bland-Altman analysis confirmed adequate results correlation (p < .05). Each employed ChS showed significantly different performance favouring the balloon expandable covered stent (BECS). The smallest gutter area was seen in the combination with Advanta V12 (0.26 cm2). MG infolding was observed in all tests. The lowest ChS compression was observed in the combination with BeGraft+ (compression 4.91%, D ratio 0.95). In our model, BECSs showed higher angulations than bare metal stents (BMSs) (p < .001).

CONCLUSION

This in vitro study shows the variability of performance with each theoretically possible ChS and explains the divergent ChS outcomes in the published literature. BECS in combination with the Endurant abdominal device confirms their superiority vs. BMS. The presence of MG infolding in each test underlines the need for prolonged kissing ballooning. Angulation evaluation and comparison with other in vitro and in vivo publications demands the need for further investigation in transversely or upwardly oriented target vessels.

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.

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.