Management of Difficult Access during Endovascular Aneurysm Repair

Systematic review and meta-analysis of incidence, indications, and outcomes of early open conversions after EVAR for abdominal aortic aneurysms

INTRODUCTION

The purpose of this study is to report incidence, indications, and outcomes of early open conversions (EOC) after endovascular aortic repair (EVAR), defined as surgical conversion performed within 30 days from the initial EVAR.

EVIDENCE AQUISITION

A systematic review of the literature was performed (database searched: PubMed, Web of Science, Scopus, Cochrane Library; last search April 2023). Articles reporting EOC after EVAR comprising at least five patients were included. Meta-analyses of proportions were performed using a random-effects model.

EVIDENCE SYNTHESIS

Seventeen non-randomized studies, published between 1999 and 2022, were included. A total of 35,970 patients had previously undergone EVAR, of these 438 patients underwent EOC. Estimated incidence of EOC was 1.4% (95% CI 1.1-1.4; I2=81.66%). Specifically, in the works published before 2010 the incidence was 1.8% (95% CI 1.3-2.4; I2=74.25) while for subsequent ones it was 0.9% (95% CI 0.6-1.1; I2=69.82). Weighted mean age was 74.91 years (95% CI 72.42-77.39; I2=83.11%). Estimated rate of cause determining EOC were: access issue in 27.7% of patients (95% CI 13.8-41.6; I2=88.14%), incorrect placement of the endograft in 20.1% (95% CI 10.2-30.0; I2=76,9%), problems with "delivery system" in 9.0% (95% CI 4.9-13.1; I2=0%), aorto-iliac rupture in 8.6% (95% CI 4.5-12.6; I2=0%), endoprosthesis migration in 7.9% of cases (95% CI 3.3-12.4; I2=22.96%), failure in engaging the contralateral gate in 4.8% (95% CI 1.6-8; I2=0%), "kinking" or "twisting" of endoprosthesis in 3.3% (95% CI 0.6-5.9; I2=0%), graft thrombosis in 3.2% (95% CI 0.6-5.7; I2=0%), type Ia endoleak in 2.9% (95% CI 0.4-5.4; I2=0%), type III endoleak in 2.8% (95% CI 0.3-5.3; I2=0%) and endograft infection in 2.7% (95% CI 0.3-5.2; I2=0%). Intraoperative conversion rate was 91.1% (95% CI 85.8-96.4; I2=66.01%). Early mortality rate after EOC was 14.5% (95% CI 9.1-19.9; I2=48.31%). Mean length of stay (LOS) was 11.94 days (95% CI 6.718-17.172; I2=92.34%).

CONCLUSIONS

The incidence of EOC seems to decrease over time. Causes of EOC were mainly related to access problems and incorrect positioning of the endograft. Most of the EOC were performed intraoperatively carrying a high mortality rate.

Impact of iliac access in elective and non-elective endovascular repair of abdominal aortic aneurysm

Endovascular aortic repair (EVAR) is nowadays the establishment treatment for patients with abdominal aortic aneurysm (AAA) both in elective and urgent setting. Despite the large applicability and satisfactory results, the presence of hostile iliac anatomy affects both technical and clinical success. This narrative review aimed to report the impact of iliac access and related adjunctive procedures in patients undergoing EVAR in elective and non-elective setting. Hostile iliac access can be defined in presence of narrowed, tortuous, calcified, or occluded iliac arteries. These iliac characteristics can be graded by the anatomic severity grade score to quantitatively assess anatomic complexity before undergoing treatment. Literature shows that iliac hostility has an impact on device navigability, insertion and perioperative and postoperative results. Overall, it has been correlated to higher rate of access issues, representing up to 30% of the first published EVAR experience. Recent innovations with low-profile endografts have reduced large-bore sheaths related issues. However, iliac-related complications still represent an issue, and several adjunctive endovascular and surgical strategies are nowadays available to overcome these complications during EVAR. In urgent settings iliac hostility can significantly impact on particular time sensitive procedures. Moreover, in case of severe hostility patients might be written off for EVAR repair might be inapplicable, exposing to higher mortality/morbidity risk in this urgent/emergent setting. In conclusion, an accurate anatomical evaluation of iliac arteries during preoperative planning, materials availability, and skilled preparation to face iliac-related issues are crucial to address these challenges.

Novel Strategies for the Hostile Iliac Artery during Endovascular Aortic Aneurysm Repair

Successful endovascular aneurysm repair can be achieved with favorable aortic and iliac arterial anatomies. However, patients with challenging iliac anatomy, such as stenotic, calcified, tortuous arteries, or concomitant iliac artery aneurysms, are commonly encountered. Such a hostile iliac anatomy increases the risk of intraprocedural complications and worsens long-term outcomes. This review addresses various technical options for treating patients with a hostile iliac anatomy, including innovative endovascular solutions, physician-modified endografts, and hybrid procedures. These considerations demonstrate the wide scope of therapies that may be offered to patients with an unfavorable iliac anatomy.

Early and Midterm Outcomes of Endovascular Aneurysm Repair With Zenith Alpha Abdominal Stent-Graft: Results From a Multicenter Retrospective Tuscany Registry

PURPOSE

Zenith Alpha Abdominal (Cook Medical, Bloomington, IN, USA) is one of the new-generation low-profile stent-grafts with demonstrated satisfactory early and midterm clinical outcomes for endovascular treatment of abdominal aortic aneurysms (AAAs). The aim was to evaluate early and midterm results of this device in the framework of a multicenter regional retrospective registry, with the analysis of morphological factors affecting outcomes, including different limb configurations.

MATERIALS AND METHODS

Between January 2016 and November 2021, 202 patients with AAA underwent elective endovascular aneurysm repair (EVAR) with implantation of a Zenith Alpha Abdominal in 7 centers. Early (30 day) outcomes in terms of technical and clinical success were assessed. Estimated 5 year outcomes were evaluated in terms of survival, freedom from type I/III endoleak, freedom from surgical conversion, freedom from limb graft occlusion, freedom from any device-related reintervention, and graft infection evaluation by life-table analysis (Kaplan-Meier test). A comparative analysis between different limb configurations (Zenith Spiral Z AAA iliac legs, codes ZISL vs ZSLE) was performed in terms of limb graft occlusion.

RESULTS

The 30 day technical and clinical success rates were 97.5% and 99.5%, respectively. Median follow-up period was 25.5 months (interquartile range [IQR]: 12-43.25). The 5 year survival rate was 73.6%. The estimated 5 year outcomes in terms of freedom from type I/III endoleak, freedom from surgical conversion, freedom from limb graft occlusion, freedom from any device-related reintervention, and freedom from graft infection were 88.6% (95% CI [confidence interval]: 83.4%-93.1%), 95.8% (95% CI: 92.7%-97.1%), 93.6% (95% CI: 90.2%-96.8%), 87% (95% CI: 83.3%-91.6%), and 97.7% (95% CI: 95.1%-98.9%), respectively. About limb configuration, no differences were found in terms of 5 year freedom from limb graft occlusion (ZSLE 93.4% [95% CI: 89.8%-95.5%] vs ZISL 94.3% [95% CI: 90.1%-95.9%], p=0.342; log-rank 0.903).

CONCLUSION

Zenith Alpha Abdominal in elective EVAR offered satisfactory early and 5 year outcomes with low complication rates. Limb graft occlusion continued to be an issue. Limb configuration did not affect outcomes.

CLINICAL IMPACT

The authors describe satisfactory early and 5 year outcomes of Zenith Alpha Abdominal in elective endovascular aortic repair in the framework of a multicenter regional retrospective registry. At 5 years freedom from type I endoleak was 88.6%, and rate of endograft infections and conversions to open repair were very low. in the present study. Hot topic about about Zenith stent-graft still remains the limb graft occlusion with a 30-day overall rate of 2%, and estimated 5-year freedom from limb graft occlusion of 93.6%. Limb graft configuration did not affect limb graft occlusion rate. A standardized protocol including iliac stenting should be adopted to reduce kimb graft occlusion.

The Incraft stent graft for the treatment of abdominal aortic aneurysms: an iliac-friendly device with an effective conventional proximal sealing mechanism

INTRODUCTION

The Incraft aortic stent graft (Cordis, Bridgewater, NJ, USA) is a trimodular endovascular stent graft with a conventional suprarenal active fixation specifically designed to overcome the anatomic limitation of small, stenotic, and tortuous iliac vessels.

AREAS COVERED

The present article provides a complete description of the Incraft stent graft, its clinical performance, its technical characteristics as well as a comparison with other competitive endografts.

EXPERT OPINION

The Incraft stent graft is an EVAR ultra low-profile device initially designed for overcoming the limitation of the hostile iliac anatomy. Recently, the device is being increasingly used in real-world conditions and not only in complex iliac anatomies with good mid-term results. Whether it remains a useful EVAR toolbox or will become a workhorse endograft is yet to be determined.

Female Sex and Outcomes after Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm: A Propensity Score Matched Cohort Analysis

OBJECTIVE

Previous studies have showed a potential disadvantage of female patients who underwent abdominal aortic aneurysm (AAA) repair. The current study aims to determine sex-specific perioperative and long-term outcomes using propensity score matched unselected nationwide health insurance claims data.

METHODS

Insurance claims from a large German fund were used, covering around 8% of the insured German population. Patients who underwent endovascular aortic repair (EVAR) for intact AAA from 1 January 2011 to 30 April 2017 were included in the cohort. A 1:2 female to male propensity score matching was applied to adjust for confounding variables. Perioperative and long-term outcomes after 5 years were determined using matching and regression methods.

RESULTS

Among a total of 3736 patients (19.3% females, mean 75 years) undergoing EVAR for intact AAA, we identified 1863 matched patients. Before matching, females were more likely to be previously diagnosed with hypothyroidism, electrolyte disorders, rheumatoid disorders, and depression, while males were more often diabetics. In the matched sample, 23.4% of the females and 25.8% of the males died during a median follow-up of 776 and 792 days, respectively. Perioperatively, females were more likely to exhibit acute limb ischemia (5.3% vs. 3.2%, p = 0.031) and major bleeding (22.0% vs. 15.9%, p = 0.001) before they were discharged to rehabilitation (5.5% vs. 1.5%, p < 0.001) when compared to males. No statistically significant difference in perioperative (odds ratio 1.12, 95% CI 0.54-2.16) or long-term mortality (hazard ratio 0.91, 95% CI 0.76-1.08) was observed between sexes. This was also true regarding aortic reintervention rates after 1 year (2.0% vs. 2.9%) and 5 years (10.9% vs. 8.1%).

CONCLUSION

The current retrospective matched analysis of insurance claims revealed high early access-related morbidity in females when compared to their male counterparts. Short-term or long-term survival and reintervention outcomes were similar between sexes.

Open Surgical Repair of Abdominal Aortic Aneurysms Maintains a Pivotal Role in the Endovascular Era

Since the advent of endovascular aortic repair (EVAR) nearly three decades ago, there has been a paradigm shift in the treatment of the abdominal aortic aneurysm (AAA) to favor EVAR due to its reduced operative mortality, less invasive nature, and faster recovery times. However, more recently there has been an accumulation of data from large meta-analyses and randomized clinical trials revealing that EVAR has no survival benefit after approximately 2 years and is associated with substantially higher rates of reintervention and aneurysm rupture in the long term. These findings call into question the durability of EVAR compared with open aortic repair and emphasize the need for surgeons to remain competent with open aortic surgery in the modern era. This article will provide comprehensive review of a large body of literature comparing endovascular repair to open aortic surgery for the management of AAAs, and it will offer an overview of the open surgical repair technique for AAAs.

The Efficacy of a Protocol of Iliac Artery and Limb Treatment During EVAR in Minimising Early and Late Iliac Occlusion

OBJECTIVE

Iliac limb occlusion (ILO) is a complication of endovascular aortic repair (EVAR) and requires re-intervention in most cases. Attention to any intra-operative defect of iliac limbs and arteries may prevent ILO. The study aimed to analyse the long term effect of an intra-operative protocol of iliac limb treatment during EVAR on ILO.

METHODS

Patients treated from 2012 to 2017 for abdominal aortic aneurysm (AAA) with standard EVAR were collected prospectively. Pre-operative computed tomography angiography anatomical characteristics were evaluated. The protocol for intra-operative iliac limb management was: a. pre-EVAR angioplasty of common/external iliac artery stenosis; b. precise contralateral iliac limb deployment at the same level of the flow divider; c. iliac limb kissing ballooning with high pressure non-compliant balloons; d. iliac limb stenting for residual tortuosity/kink and adjunctive external iliac stenting for residual stenosis/dissection after EVAR. ILO was evaluated at 30 days and at follow up, which was performed by duplex ultrasonography before discharge, at three, six, and 12 months and yearly thereafter. Kaplan-Meier and Cox linear regression were used.

RESULTS

Four hundred and forty-two patients and 884 iliac limbs were included in the study. Severe iliac tortuosity and calcification were present in 15% (132/884) and 8% (70/884), respectively. External iliac angioplasty and stenting of iliac limb were performed in 2% (18/884) and 9.5% (84/884) of limbs. The thirty day mortality was 1.6%, with no ILO. At a mean follow up of 33 ± 12 months, ILO occurred in 7/884 (0.8%) limbs of six patients. Five ILO were treated by endovascular relining, two surgically: one by femorofemoral bypass and one by surgical explant. On univariable analysis, sac shrinkage was significantly associated with ILO (HR 1, 95% CI 0.8-2.5, p = .043).

CONCLUSION

A protocol of aggressive iliac limb treatment in EVAR leads to a very low rate of late ILO. The role of sac shrinkage in ILO should be investigated further.

Five-year results of the INSPIRATION study for the INCRAFT low-profile endovascular aortic stent graft system

OBJECTIVE

We present the 5-year results of a prospective regulatory study of the INCRAFT device, a low-profile endovascular stent graft system for repair of abdominal aortic aneurysms.

METHODS

This was an open-label prospective nonrandomized single-arm study enrolling in centers in the United States and Japan. The primary effectiveness outcome was successful aneurysm treatment and the primary safety outcome was the incidence of major adverse events at 30 days after the procedure. Major long-term outcomes were mortality, reintervention, adverse limb outcomes, and suprarenal stent fracture.

RESULTS

One hundred and ninety patients (mean age, 73.8 ± 7.6 years; 90% male; 69% white and 30% Asian) were enrolled from 32 centers throughout the United States and Japan. Minimal access vessel size was less than 7 mm on both sides in 43.9% of the study cohort. Thirty-day major adverse events occurred in 3.2% of patients (6/190). Periprocedural technical success was 94.1% (176/187). Successful aneurysm treatment was 100% at 30 days and 87.9% at 1 year. Two patients required open conversion for thromboembolic complications, 3 developed new type I or III endoleaks, and 7 experienced graft or limb occlusion. Freedom from graft occlusion was 96 ± 2% at 1 year and 94 ± 2% at 5 years. Freedom from stent fracture was 97 ± 1% at 1 year and 87 ± 3% at 5 years. Freedom from aneurysm-related mortality was 99 ± 1% at 1 and 5 years.

CONCLUSIONS

This study demonstrates good efficacy and safety and a very low rate of aneurysm related deaths with the INCRAFT device in a population with a high proportion of challenging anatomy.

Development of a Magnetic Kissing Guidewire and Animal Experiment: a Preliminary Study

Endovascular therapy has been the first option for many vascular diseases. Due to the increasing development of endovascular devices and techniques in recent decades, endovascular procedures could be applied in treating those cases with complex anatomy. Two or three vascular access routes are required to establish through-and-through access in endovascular therapy for arterial occlusive disease and complex aortic aneurysm. Guidewire snaring with a snare kit is essential but sometimes time-consuming in the establishment of through-and-through access. To simplify the procedure, we design the magnetic kissing guidewire (MKG) with a magnetic tip that attracts each other to establish a guidewire route that meets the needs of clinical practice. We conducted the in vitro test to evaluate its magnetic force and the in vivo test to assess its performance in the arteries of twelve sheep. The results revealed that this novel guidewire significantly simplified the establishment of through-and-through access.

Genetic and epigenetic regulation of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are focal dilations of the aorta that develop from degenerative changes in the media and adventitia of the vessel. Ruptured AAAs have a mortality of up to 85%, thus it is important to identify patients with AAA at increased risk for rupture who would benefit from increased surveillance and/or surgical repair. Although the exact genetic and epigenetic mechanisms regulating AAA formation are not completely understood, Mendelian cases of AAA, which result from pathologic variants in a single gene, have helped provide a basic understanding of AAA pathophysiology. More recently, genome wide associated studies (GWAS) have identified additional variants, termed single nucleotide polymorphisms, in humans that may be associated with AAAs. While some variants may be associated with AAAs and play causal roles in aneurysm pathogenesis, it should be emphasized that the majority of SNPs do not actually cause disease. In addition to GWAS, other studies have uncovered epigenetic causes of disease that regulate expression of genes known to be important in AAA pathogenesis. This review describes many of these genetic and epigenetic contributors of AAAs, which altogether provide a deeper insight into AAA pathogenesis.

Use of a balloon-expandable sheath for transfemoral complex endovascular aortic repair

Authors' Note: On April 30, 2019, Terumo Medical Corporation issued a voluntary product recall for and discontinued manufacturing of the SoloPath Balloon Expandable Sheath System, the device used for the procedures outlined in this article. Data collection, data analysis, and manuscript submission occurred prior to notice of this recall. The authors of this article were unaware of adverse events associated with this device and the 15 procedures reviewed for this series were free of events related to the reason for this device recall. Management of iliac artery disease remains a challenging problem in the setting of complex endovascular aortic procedures. In spite of the nonavailability of the device outlined in this article, the authors feel that the value of innovative solutions to this clinical problem (including the use of a balloon expandable sheath) merits public review of this technique and its results. Vascular access complications contribute to the morbidity of fenestrated endovascular aneurysm repair (FEVAR). As the ability to perform these procedures progresses, new techniques emerge to overcome difficult peripheral vascular anatomy and to minimize these complications. We describe our use of a balloon-expandable sheath to accommodate the multiple accesses needed for bridging stent placement during FEVAR in patients with highly calcified, tortuous, or small-diameter access vessels. We used this sheath for successful completion of FEVAR in 15 patients with challenging iliofemoral disease. There was one iliofemoral complication and no limb loss. Given the significant source of morbidity that vascular access complications contribute to endovascular procedures, we believe that a balloon-expandable sheath is a useful adjunct in FEVAR with complex iliac anatomy.