Early and Late Clinical Outcomes of Endovascular Aneurysm Repair in Patients with an Angulated Neck

Influence of severe neck angulation on hemodynamic and clinical outcomes following endovascular aneurysm repair: a hemodynamic analysis and a retrospective cohort study

BACKGROUND

For patients with severe neck angulation (SNA), hemodynamic and clinical outcomes following endovascular aneurysm repair (EVAR) are still unclear. This study aimed to explore the influence of SNA on hemodynamic and clinical outcomes following EVAR.

METHODS

This study included a hemodynamic analysis and a retrospective cohort study from West China Hospital of Sichuan University between January 2011 and December 2020. The Cox regression model, inverse probability of treatment weighting (IPTW) analysis, sensitivity analysis, and subgroup analysis were applied. Primary outcome was type IA endoleak (T1AEL).

RESULTS

In this hemodynamic analysis, nine non-severe neck angulation (nSNA) and 16 SNA idealized models were constructed. We found a significant difference in drag force between SNA and nSNA models (7.016 ± 2.579 N vs. 4.283 ± 1.460 N, P = 0.008), and proximal neck angles were significantly associated with the magnitude of drag force (F = 0.082 × α-0.006 × β + 2.818, α: 95% confidence interval [CI] 0.070-0.094; P = 0.001; β: 95% CI -0.019 to 0.007; P = 0.319). In our cohort study, 514 nSNA patients (71.5 ± 8.5 years; 459 males) and 208 SNA patients (72.5 ± 7.8 years; 135 males) were included, with a median follow-up duration of 34 months (16-63 months). All baseline characteristics were well balanced after IPTW matching. We found that SNA was associated with a significant risk of adverse limb event (hazard ratio [HR] 2.18, 95% CI 1.09-3.12), yet was not associated with T1AEL, overall survival, or reintervention. In patients without proximal or distal additional procedures (DAP), subgroup analyses suggested a significant risk of T1AEL (Proximal: HR 5.25, 95% CI 1.51-18.23; Distal: HR 5.07, 95% CI 1.60-16.07) and adverse limb event (Proximal: HR 2.27, 95% CI 1.01-5.07; Distal: HR 2.91, 95% CI 1.30-6.54) in SNA patients. However, no noticeable difference was observed in patients with proximal or DAP.

CONCLUSIONS

SNA has a critical influence on hemodynamic and clinical outcomes following EVAR. Appropriate additional procedures may be of great benefit to SNA patients.

Pre-operative Aortic Neck Characteristics and Post-operative Sealing Zone as Predictors of Type 1a Endoleak and Migration After Endovascular Aneurysm Repair: A Systematic Review and Meta-Analysis

OBJECTIVE

Establishing the predictive value of neck characteristics and real achieved sealing zone is essential to foster risk stratified procedure selection and imaging surveillance. This systematic review provides an overview of pre-operative aortic neck characteristics and post-operative real achieved sealing zone and their respective risk of type 1a endoleak and migration after endovascular aneurysm repair (EVAR).

METHODS

In agreement with PRISMA guidelines, MEDLINE, Embase, and Cochrane CENTRAL were searched. Data on neck characteristics, sealing zone, and EVAR outcome were extracted. Meta-analyses were performed to investigate the effect of neck diameter, angulation, and shape on type 1a endoleak (total, early ≤ 90 days, and late > 90 days) and migration in patients who underwent EVAR. A qualitative summary was also provided.

RESULTS

Thirty-three studies were included. Patients with a larger neck diameter had an increased risk of total type 1a endoleak (nine studies: OR 3.32, 95% CI 2.38 - 4.63), early type 1a endoleak (six studies: OR 2.64, 95% CI 1.27 - 5.48), late type 1a endoleak (six studies: OR 3.26, 95% CI 2.12 - 5.03), and migration (seven studies: OR 2.88, 95% CI 1.32 - 6.26). An angulated neck increased the risk of total type 1a endoleak (seven studies: OR 4.27, 95% CI 1.55 - 11.78) and late type 1a endoleak (seven studies: OR 5.56, 95% CI 2.19 - 14.13). Neck shape was not associated with type 1a endoleak. Neck length and real achieved sealing zone on post-EVAR computed tomography were identified as risk factors for type 1a endoleak and migration through qualitative summary.

CONCLUSION

There seems to be some consistent evidence that aortic neck diameter, angulation, and length are associated with the development of type 1a endoleak or migration. Real achieved sealing zone might be an important addition during follow up. However, a small number of studies, with serious limitations, could be included, and there was considerable variability in reporting patients and outcomes. A proposal for standardisation of aortic and EVAR data in future studies is provided.

A meta-analysis of safety and efficacy of endovascular aneurysm repair in aneurysm patients with severe angulated infrarenal neck

Objectives

A growing number of abdominal aortic aneurysms with severe angulated neck anatomy is treated by endovascular means. However, contradictory early and late outcomes have been reported. Our review and outcome analysis attempted to evaluate the available literature and provide clinicians with a base for clinical implementation and future research.

Materials and methods

A systematic review of the literature was undertaken to identify the outcomes of endovascular aneurysm repair in patients with severe infrarenal neck angulation (SNA ≥ 60°) vs non-severe neck angulation (NSNA). Outcome measures included perioperative complications, type 1a endoleak, neck-related secondary procedures, stent graft migration, aneurysm rupture, increase (>5mm) in sac diameter, all-cause and aneurysm-related mortality (PROSPERO Nr.: CRD42021233253).

Results

Six observational studies reporting on 5981 patients (1457 with SNA and 4524 with NSNA) with a weighted mean follow-up period of 1.8 years were included. EVAR in SNA compared with NSNA was associated with a higher rate of type 1a endoleak at 30 days (4.0% vs 1.8%; p< 0.00001), at 1 year (2.8% vs 1.9%; p<0.03), at 2 years (4.9% vs 2.1%; p< 0.0002), at 3 years (5.6% vs 2.6%; p< 0.0001). The rate of neck-related secondary procedures was significantly higher at 1 year (6.6% vs 3.9%; p<0.05) and at 3 years (13.1% vs 9%; p<0.05). Graft migration, aneurysm sack increase, aneurysm rupture and all-cause mortality were not statistically different at mid-term.

Conclusions

The use of EVAR in severely angulated infrarenal aortic necks is associated with a high rate of early and mid-term complications. However, aortic related and all-causes mortality are not higher compared to patients with NSNA. Therefore, EVAR should be cautiously used in patients with SNA.

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.

Prognostic Role of Severe Infrarenal Aortic Neck Angulation in Endovascular Aneurysm Repair

OBJECTIVE

To investigate whether patients with severe infrarenal aortic neck angulation have worse outcomes than those without severe angulation after endovascular aneurysm repair (EVAR).

DATA SOURCES

The HDAS (Healthcare Database Advanced Search) interface developed by NICE (National Institute for Health and Care Excellence) was used to search electronic bibliographic databases.

REVIEW METHODS

Studies comparing outcomes of standard EVAR in patients with and without severe neck angulation were considered. Pooled outcome estimates were calculated using the odds ratio (OR) or hazard ratio (HR) and 95% confidence interval (CI), using the Mantel-Haenszel or inverse variance method, as appropriate. Random effects models of meta-analysis were applied. The GRADE (Grading of Recommendation, Assessment, Development, and Evaluation) methodology was used to assess the certainty of evidence.

RESULTS

Ten studies reporting a total of 7 371 patients (1 576 with severe neck angulation and 5 795 without) were included. The studies reported medium term follow up. No statistically significant difference was found for the primary outcomes (overall mortality: HR 1.27, 95% CI 0.88 - 1.85, low certainty; aneurysm related mortality: HR 1.07, 95% CI 0.80 - 1.44, moderate certainty; aneurysm rupture: HR 1.41, 95% CI 0.66 - 2.99, low certainty). The hazard of type Ia endoleak (HR 1.86, 95% CI 1.32 - 2.61) and re-intervention was higher in patient with severe angulation (HR 1.24, 95% CI 1.01 - 1.54), but there was no significant difference in the odds of adjunctive procedures (OR 1.23, 95% CI 0.48 - 3.11), or the hazard of sac expansion (HR 0.83, 95% CI 0.44 - 1.55) or stent migration (HR 1.22, 95% CI 0.78 - 1.92). Meta-analysis of studies that conducted multiple Cox regression analysis showed no significant difference for any of the primary outcomes.

CONCLUSION

Severe neck angulation may not be a poor prognostic indicator for overall/aneurysm related mortality and rupture in the medium term after EVAR but may increase the risk of late type 1 endoleaks and re-intervention; therefore, patients require close surveillance.

Early and late outcomes of endovascular aneurysm repair to treat abdominal aortic aneurysm compared between severe and non-severe infrarenal neck angulation

Background

Abdominal aortic aneurysm with severe infrarenal neck angle (>60°) has long been thought to be an obstacle to endovascular aneurysm repair. However, some previous studies reported endovascular aneurysm repair to be safe and efficacious for treating abdominal aortic aneurysm in patients with severe neck angulation. The aim of this study was to investigate the early and late outcomes of endovascular aneurysm repair to treat abdominal aortic aneurysm compared between patients with severe and non-severe infrarenal neck angulation.

Methods

Fifty-four severe and 144 non-severe neck angulation patients who were treated at Siriraj Hospital (Bangkok, Thailand) during January 2010–October 2013 were recruited. The primary endpoints were intraoperative neck complications (e.g., type 1A endoleak or proximal graft migration) and immediate adjunct aortic neck procedures. The secondary endpoints included perioperative mortality, overall survival, and the proportion of patients that were reintervention-free at five years compared between the severe and non-severe groups.

Results

Severe angulation patients were significantly older than non-severe angulation patients (77 ± 6.3 vs. 74 ± 7.9 years; p =  0.021). The median proximal angle was significantly greater in the severe group (82° vs. 13.5°; p <  0.001). Intraoperative proximal neck complications developed in 29.6% of patients in the severe angulation group compared with 9.0% in the non-severe group ( p <  0.001). Significantly more patients in the severe group required intraoperative adjunct procedures (29.6% vs. 7.6%; p <  0.001). There was no significant difference in perioperative mortality between groups. At the five-year follow-up, there was no significant difference between groups for overall survival or the proportion of patients that remained reintervention-free.

Conclusions

Endovascular aneurysm repair to treat abdominal aortic aneurysm in patients with severe proximal neck angulation is technically feasible and safe Although the severe angulation group had a higher rate of intraoperative neck complications and immediate adjunct neck procedures than the non-severe group, there was no significant difference between groups for 30-day mortality, overall survival or the proportion of patients who remained reintervention-free at five years.

Advanced endografting techniques: snorkels, chimneys, periscopes, fenestrations, and branched endografts

The anatomy of aortic aneurysms from the proximal neck to the access vessels may create technical challenges for endovascular repair. Upwards of 30% of patients with abdominal aortic aneurysms (AAA) have unsuitable proximal neck morphology for endovascular repair. Anatomies considered unsuitable for conventional infrarenal stent grafting include short or absent necks, angulated necks, conical necks, or large necks exceeding size availability for current stent grafts. A number of advanced endovascular techniques and devices have been developed to circumvent these challenges, each with unique advantages and disadvantages. These include snorkeling procedures such as chimneys, periscopes, and sandwich techniques; "homemade" or "back-table" fenestrated endografts as well as manufactured, customized fenestrated endografts; and more recently, physician modified branched devices. Furthermore, new devices in the pipeline under investigation, such as "off-the-shelf" fenestrated stent grafts, branched stent grafts, lower profile devices, and novel sealing designs, have the potential of solving many of the aforementioned problems. The treatment of aortic aneurysms continues to evolve, further expanding the population of patients that can be treated with an endovascular approach. As the technology grows so do the number of challenging aortic anatomies that endovascular specialists take on, further pushing the envelope in the arena of aortic repair.

Treatment of Hostile Proximal Necks During Endovascular Aneurysm Repair

Endovascular aneurysm repair (EVAR) is a therapy that continues to evolve rapidly as advances in technology are incorporated into new generations of devices and surgical practice. Although EVAR has emerged as a safe and effective treatment for patients with favorable anatomy, treatment of patients with unfavorable anatomy remains controversial and is still an off-label indication for endovascular treatment with some current stent-grafts. The proximal neck of the aneurysm remains the most hostile anatomic barrier to successful endovascular repair with long-term durability. Open surgery for unfavorable necks is still considered the gold standard treatment in contemporary practice, despite the increased mortality and morbidity attributed to suprarenal cross-clamping, particularly in high-risk patients. Evolving technology may overcome the obstacles preventing endovascular treatment of unfavorable proximal neck anatomy; current approaches include purely endovascular as well as hybrid approaches, and generally include strategies that either extend the length of the short neck, move the proximal neck more proximally, or keep the short neck intact. These approaches include the use of debranching techniques, banding, chimneys, fenestrated and branched devices, filling the sac with endobags, endoanchors, and other novel devices. These newer-generation devices appear to have promising short- and midterm results. However, lack of good evidence of efficacy with long-term results for these newer approaches still precludes wide dissemination of endovascular solutions for the hostile proximal neck.

Endovascular aortic aneurysm repair with chimney and snorkel grafts: indications, techniques and results

The chimney technique in endovascular aortic aneurysm repair (Ch-EVAR) involves placement of a stent or stent-graft parallel to the main aortic stent-graft to extend the proximal or distal sealing zone while maintaining side branch patency. Ch-EVAR can facilitate endovascular repair of juxtarenal and aortic arch pathology using available standard aortic stent-grafts, therefore, eliminating the manufacturing delays required for customised fenestrated and branched stent-grafts. Several case series have demonstrated the feasibility of Ch-EVAR both in acute and elective cases with good early results. This review discusses indications, technique, and the current available clinical data on Ch-EVAR.

Thromboembolic complications after endovascular repair of abdominal aortic aneurysm with neck thrombus

OBJECTIVE

To evaluate outcomes after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) with neck thrombus.

METHODS

We retrospectively reviewed patients who underwent EVAR for AAA at our institution from 2007 to 2011. Patients with ruptured AAA, chronic renal failure, or hostile neck characteristics other than thrombus were excluded. Patients were divided into 2 groups: group T (with neck thrombus) and group N (without neck thrombus). We compared complications and mid-term outcomes.

RESULTS

There were no differences in success rates between the groups, but there were higher rates of thromboembolic complications such as distal embolization (20% vs 0%, P = .02) and renal dysfunction (36.8% vs 11.1%, P = .03) in group T than in group N. Suprarenal thrombus and suprarenal fixation in the presence of suprarenal thrombus were associated with postoperative renal dysfunction (P = .01).

CONCLUSION

The EVAR for AAA with neck thrombus is associated with thromboembolic complications.

Coupling bifurcated stent-grafts to overcome anatomic limitations of endovascular repair of abdominal aortic aneurysms

PURPOSE

To evaluate the effectiveness of the coupling stent-graft technique and outcomes on contrast-enhanced computed tomography (CT).

MATERIALS AND METHODS

All patients who underwent endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) between 2007 and 2010 at a single institution were retrospectively analyzed. Of the 161 cases, 19 patients who had coupling stent-grafting because of AAA proximal neck angulation greater than 60°, conical neck, or iliac tortuosity were included. Patient age ranged from 62 to 87 years (mean, 73.3 y). Mean follow-up was 18.7 months (range, 1-36 mo). The coupling stent-graft technique was defined by the use of suprarenal fixation device main bodies (Zenith or Talent) with one or more EXCLUDER limbs to adapt tortuous and angulated iliac arteries. Pretreatment contrast-enhanced CT was analyzed based on three-dimensional and multiplanar reformatted images. Follow-up contrast-enhanced CT was also analyzed.

RESULTS

Mean aneurysm diameter was 68.9 mm ± 14.0, neck length was 32.7 mm ± 15.1, and neck angulation was 68.9° ± 11.5. Conical neck shapes were present in four patients (21.1%) and ruptured AAAs were present in two (10.5%). Among 38 iliac arteries, the mean iliac artery tortuosity index was 1.52 ± 0.27 and iliac angle was 106.8° ± 18.1. Three patients (15.8%) underwent repeat intervention: placement of a balloon-expandable stent in the proximal neck for type I endoleak (n = 1), endovascular embolization for proximal type I endoleak (n = 1), and percutaneous approach following endovascular embolization for type II endoleak (n = 1). No type III endoleak, limb occlusion, limb kinking, or stent-graft migration developed.

CONCLUSIONS

The coupling stent-graft technique is technically feasible, with acceptable midterm outcomes in EVAR of AAA in patients with unfavorable neck and iliac anatomies.

Alternative Technique for Endovascular Treatment of an Abdominal Aortic Aneurysm With a Severely Angulated Neck

An 86-year-old female was incidentally discovered with an asymptomatic 5.3 cm infrarenal aortic aneurysm. Preoperative imaging demonstrated the aortic neck to have severe suprarenal and infrarenal angulation. The patient was deemed unfit for open aortic repair due to multiple medical comorbidities. Endovascular treatment was performed with a modified Zenith bifurcated graft using a Zenith TX2 endograft as a proximal aortic cuff. There were no perioperative complications, and postoperative imaging demonstrated aneurysm exclusion with no migration or major endoleaks. The patient died of unrelated causes at 21 months. The use of a thoracic endograft as a proximal cuff is an alternative technique in the endovascular treatment of abdominal aortic aneurysms with a severely angulated neck.

Long-term outcome of open or endovascular repair of abdominal aortic aneurysm

Study objective: To evaluate long-term outcomes of endovascular or open abdominal aortic aneurysm (AAA) repair in patients who were enrolled in the Dutch Randomized Endovascular Aneurysm Repair (DREAM) study.

Study population: Patients were eligible for DREAM if they had an AAA measuring at least 50 mm in diameter, and were considered candidates for either mode of repair. Patients were excluded if they required emergency aneurysm repair, had inflammatory aneurysms, anatomic variations precluding repair, connective tissue disease, previous organ transplantation or a life expectancy of less than 2 years. Suitability for endovascular repair was primarily based on anatomic criteria. Patients were deemed suitable for open repair based on the opinion of a cardiologist or internist.

Design and methods: This study is a secondary analysis of long-term outcomes of patients enrolled in the DREAM study, a multi-centered, randomized, clinical trial. Randomization initially occurred in a 1:1 ratio via computer algorithm, and was stratified according to center in a permuted-block sequence of four patients. While the original analysis of DREAM examined short-term mortality and complications, the primary outcomes outlined in this analysis were long-term death from any cause and the need for repeat intervention. A reintervention was defined as a repeat procedure related to the initial repair secondary to a graft (e.g. prosthesis infection or type 1 endoleak), wound (e.g. incisional hernia or wound infection), or local or systemic complication. The primary analysis was intention to treat. After the second year of enrollment, patients received biannual questionnaires evaluating physical health and utilization of medical resources, with additional data collected based on routine clinical care. At the conclusion of the study period, follow-up was attempted on all patients either directly, or through their relatives or physicians.

Results: The DREAM study randomly enrolled 178 patients to undergo open repair and 173 patients to undergo endovascular repair. Data collection for this analysis was stopped after a mean follow-up of 6.4 years (CI: 5.1 to 8.2). Baseline characteristics were similar in both groups regarding associated cardiac disease and cardiovascular risk factors. Long-term follow-up was high in both the open repair group (99.3%) and endovascular group (99.7%). At the conclusion of the study, overall survival rates were 69.9% in the open repair group and 68.9% in the endovascular group ( p = 0.97, 95% confidence interval (CI): —8.8 to 10.8). Freedom from reintervention was significantly higher in the open repair group compared to the endovascular group (81.9% vs 70.4%, p = 0.03; 95% CI: 2.0 to 21.0). The most common cause for reintervention in the endovascular group was endograft related (75.0%). Patients in the open group most commonly underwent reintervention for an incisional hernia (46.7%).

Conclusions: Endovascular and open repair for AAA have similar survival outcomes at 6 years. There is an increased rate of reintervention associated with endovascular repair, primarily due to graft-related complications.