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Arteriosclerosis, Thrombosis, and... Jun 2019Objective- Isolated common iliac artery aneurysms (CIAA) are rare. Their prognosis and influence on aortoiliac blood flow and remodeling are unclear. We evaluated the...
Objective- Isolated common iliac artery aneurysms (CIAA) are rare. Their prognosis and influence on aortoiliac blood flow and remodeling are unclear. We evaluated the hypotheses that morphology at and distal to the aortic bifurcation, together with the associated hemodynamic changes, influence both the natural history of CIAA and proximal aortic remodeling. Approach and Results- Twenty-five isolated CIAAs (15 intact, 10 ruptured), in 23 patients were reconstructed and analyzed with computational fluid dynamics: all showed abnormal flow. Then we studied a series of 24 hypothetical aortoiliac geometries in silico with varying abdominal aortic deflection and aortic bifurcation angles: key findings were assessed in an independent validation cohort of 162 patients. Wall shear stress in isolated unilateral CIAAs was lower than the contralateral common iliac artery, 0.38±0.33 Pa versus 0.61±0.24 Pa, inversely associated with CIAA diameter ( P<0.001) and morphology (high shear stress in variants distal to a sharp kink). Rupture usually occurred in regions of elevated low and oscillatory shear with a wide aortic bifurcation angle. Abdominal aortas deflected towards the CIAA for most unilateral isolated CIAAs (14/21). In silico, wider bifurcation angles created high focal regions of low and oscillatory shear in the common iliac artery. The associations of unilateral CIAA with aortic deflection and common iliac artery diameter with bifurcation angle were confirmed in the validation cohort. Conclusions- Decreasing wall shear stress is strongly associated with CIAA progression (larger aneurysms and rupture), whereas abnormal blood flow in the CIAA seems to promote proximal aortic remodeling, with adaptive lateral deflection of the abdominal aorta towards the aneurysmal side.
Topics: Adaptation, Physiological; Aneurysm, Ruptured; Aorta, Abdominal; Computer Simulation; Europe; Female; Hemodynamics; Humans; Hydrodynamics; Iliac Aneurysm; Iliac Artery; Male; Models, Cardiovascular; Retrospective Studies; Stress, Mechanical; Vascular Remodeling
PubMed: 31018660
DOI: 10.1161/ATVBAHA.119.312687 -
The Cochrane Database of Systematic... Jul 2020Endovascular aortic aneurysm repair (EVAR) is used to treat aorto-iliac and isolated iliac aneurysms in selected patients, and prospective studies have shown advantages...
BACKGROUND
Endovascular aortic aneurysm repair (EVAR) is used to treat aorto-iliac and isolated iliac aneurysms in selected patients, and prospective studies have shown advantages compared with open surgical repair, mainly in the first years of follow-up. Although this technique produces good results, anatomic issues (such as common iliac artery ectasia or an aneurysm that involves the iliac bifurcation) can make EVAR more complex and challenging and can lead to an inadequate distal seal zone for the stent-graft. Inadequate distal fixation in the common iliac arteries can lead to a type Ib endoleak. To avoid this complication, one of the most commonly used techniques is unilateral or bilateral internal iliac artery occlusion and extension of the iliac limb stent-graft to the external iliac arteries with or without embolisation of the internal iliac artery. However, this occlusion is not without harm and is associated with ischaemic complications in the pelvic territory such as buttock claudication, sexual dysfunction, ischaemic colitis, gluteal necrosis, and spinal cord injury. New endovascular devices and alternative techniques such as iliac branch devices and the sandwich technique have been described to maintain pelvic perfusion and decrease complications, achieving revascularisation of the internal iliac arteries in patients not suitable for an adequate seal zone in the common iliac arteries. These approaches may also preserve the quality of life of treated individuals and may decrease other serious complications including spinal cord ischaemia, ischaemic colitis, and gluteal necrosis, thereby decreasing the morbidity and mortality of EVAR.
OBJECTIVES
To assess the effects of internal iliac artery revascularisation versus internal iliac artery occlusion during endovascular repair of aorto-iliac aneurysms and isolated iliac aneurysms involving the iliac bifurcation.
SEARCH METHODS
The Cochrane Vascular Information Specialists searched the Cochrane Vascular Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library; MEDLINE; Embase; the Cumulative Index to Nursing and Allied Health Literature (CINAHL); and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 28 August 2019. The review authors searched Latin American Caribbean Health Sciences Literature (LILACS) and the Indice Bibliográfico Español de Ciencias de la Salud (IBECS) on 28 August 2019 and contacted specialists in the field and manufacturers to identify relevant studies.
SELECTION CRITERIA
We planned to include all randomised controlled trials (RCTs) that compared internal iliac artery revascularisation with internal iliac artery occlusion for patients undergoing endovascular treatment of aorto-iliac aneurysms and isolated iliac aneurysms involving the iliac bifurcation.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed identified studies for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions.
MAIN RESULTS
We identified no RCTs that met the inclusion criteria.
AUTHORS' CONCLUSIONS
We found no RCTs that compared internal iliac artery revascularisation versus internal iliac artery occlusion for endovascular treatment of aorto-iliac aneurysms and isolated iliac aneurysms involving the iliac bifurcation. High-quality studies that evaluate the best strategy for managing endovascular repair of aorto-iliac aneurysms with inadequate distal seal zones in the common iliac artery are needed.
Topics: Aortic Aneurysm, Abdominal; Embolization, Therapeutic; Endovascular Procedures; Humans; Iliac Aneurysm; Iliac Artery
PubMed: 32691854
DOI: 10.1002/14651858.CD013168.pub2 -
Journal of Vascular Surgery Oct 2022Iliac branch devices (IBDs) have been used in the treatment of aortoiliac and isolated iliac artery aneurysms. The aim of this systematic review and meta-analysis was to... (Meta-Analysis)
Meta-Analysis Review
A systematic review and meta-analysis of the clinical effectiveness and safety of unilateral versus bilateral iliac branch devices for aortoiliac and iliac artery aneurysms.
OBJECTIVE
Iliac branch devices (IBDs) have been used in the treatment of aortoiliac and isolated iliac artery aneurysms. The aim of this systematic review and meta-analysis was to investigate the clinical effectiveness and safety of IBDs.
METHODS
A systematic review of the literature was conducted by identifying studies in the Medline, EMBASE, and Cochrane databases regarding the outcomes of IBDs in aortoiliac or isolated iliac artery aneurysms between May 2006 and December 2020. Individual studies were evaluated for the following major outcomes: technical success, 30-day mortality, primary patency, endoleak, reintervention, and rates of pelvic ischemia. Furthermore, subgroup meta-analyses were performed to compare the pelvic ischemic events in patients with bilateral IBDs, unilateral IBDs, and bilateral internal iliac artery (IIA) embolization/coverage.
RESULTS
Forty-five studies with a total of 2736 patients undergoing unilateral or bilateral IBDs met inclusion criteria and were included in the analysis. The pooled technical success rate of IBDs was 98.0% (confidence interval [CI]: 97.3%-98.7%). After IBD treatment, the 30-day mortality rate was 0.4% (CI: 0.07%-0.70%); 30-day patency was 98.4% (CI: 97.7%-99.0%); buttock claudication developed in 1.84% (CI: 1.26%-2.41%); and endoleak occurred in 11.9% (CI: 9.2%-14.7%) and reintervention in 7.6% (CI: 5.65%-9.58%). Furthermore, in patients with bilateral iliac artery involvement, the pooled estimate rates of buttock claudication were 0.7% in the bilateral IBD group, 7.9% in unilateral IBD with contralateral IIA embolization patients, and 33.8% in bilateral IIA embolization/coverage patients, which were statistically significant among the three groups. Sexual dysfunction was 5.0% in the bilateral IIA occlusion group, which was significantly higher than that in IBD groups.
CONCLUSIONS
The utilization of IBDs in the treatment of aortoiliac or isolated iliac artery aneurysms is associated with high technical success rates as well as low incidences of pelvic ischemia. The risk of postoperative buttock claudication can be further decreased with both IIA preservation if patients are anatomically suitable for bilateral IBDs.
Topics: Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Endoleak; Endovascular Procedures; Humans; Iliac Aneurysm; Iliac Artery; Intermittent Claudication; Ischemia; Prosthesis Design; Stents; Treatment Outcome
PubMed: 35314303
DOI: 10.1016/j.jvs.2022.03.005 -
Journal of Vascular Surgery Feb 2023
Topics: Humans; Iliac Artery; Iliac Aneurysm; Diagnostic Imaging; Blood Vessel Prosthesis Implantation; Aortic Aneurysm, Abdominal; Stents
PubMed: 36681488
DOI: 10.1016/j.jvs.2022.08.044 -
European Journal of Vascular and... Apr 2018The objective was to summarise the lessons learned, and evolution in local practice over the last 7 years, in the investigation and surgical management of iliac artery...
OBJECTIVE/BACKGROUND
The objective was to summarise the lessons learned, and evolution in local practice over the last 7 years, in the investigation and surgical management of iliac artery endofibrosis.
METHODS
This was a retrospective case series. A case note review of consecutive patients investigated for suspected iliac artery endofibrosis by a single surgeon, over a 7 year period, was undertaken. Included were cases of first presentation and those who had previously undergone intervention.
RESULTS
Some 63 patients were referred with suspected endofibrosis in the period 2011-17, four of whom had previously undergone surgery for the condition. After investigation of both limbs, 50 symptomatic limbs in 46 patients had a confirmed diagnosis; amongst those 46 patients, iliac artery endofibrosis was found in a further six asymptomatic, contralateral limbs. Individuals were diagnosed at a median age of 36 years (range 18-52 years) and typically presented with thigh claudication, foot numbness, and limb weakness on exercise. The median delay to diagnosis was 3 years (range 0-14 years). Complete external iliac artery occlusion was a feature in three cases. Overall, 27 limbs in 25 patients underwent operative repair; a further five limbs in four patients underwent operative repair at other centres internationally. There were three post-operative superficial wound infections (11%) and one below knee deep vein thrombosis (4%). Symptoms resolved in 23 cases (85%) with a median follow up of 2.1 years (range 65 days-5.7 years). Of the four limbs developing recurrent symptoms, two had undergone surgery for an occluded external iliac artery.
CONCLUSION
Surgical repair in the medium term appears effective in resolving symptoms in most patients. Further investigation is needed to establish the durability of surgery and to delineate the natural history of the disease.
Topics: Adolescent; Adult; Angioplasty; Female; Fibrosis; Hemodynamics; Humans; Iliac Artery; Male; Middle Aged; Peripheral Arterial Disease; Postoperative Complications; Regional Blood Flow; Remission Induction; Retrospective Studies; Severity of Illness Index; Time Factors; Treatment Outcome; Vascular Surgical Procedures; Young Adult
PubMed: 29548540
DOI: 10.1016/j.ejvs.2018.01.018 -
Acta Biomaterialia Apr 2021Mechanical properties of vascular grafts likely play important roles in healing and tissue regeneration. Healthy arteries are compliant at low pressures but stiffen...
Mechanical properties of vascular grafts likely play important roles in healing and tissue regeneration. Healthy arteries are compliant at low pressures but stiffen rapidly with increasing load, ensuring sufficient volumetric expansion without overstretching the vessel. Commercial synthetic vascular grafts are stiff and unable to expand under physiologic loads, which may result in altered hemodynamics, deleterious cellular responses, and compromised clinical performance. The goal of this study was to develop an Elastomeric Nanofibrillar Graft (ENG) with artery-tuned nonlinear compliance and compare its healing responses to conventional expanded polytetrafluoroethylene (ePTFE) grafts in a porcine iliac artery model. Human and porcine iliac arteries were mechanically characterized, and an ENG with similar properties was created by utilizing residual strains within electrospun nanofibers. The ENG was tested for implantation suitability and implanted onto n = 5 domestic swine iliac arteries, with control ePTFE grafts implanted onto the contralateral iliac arteries. After two weeks in vivo, all iliac arteries and grafts remained patent with no signs of thrombosis or dilation. The mechanically tuned ENG implants exhibited a more confluent CD31-positive cell monolayer (1.53 ± 0.73 µm/mm vs 0.52 ± 0.55 µm/mm, p = 0.042) on the graft lumenal surface and a higher fraction of αSMA-positive cells (16.2 ± 8.6% vs 1.4 ± 0.7%, p = 0.018) within the graft wall than the ePTFE controls. Despite heavy cellular infiltration, the ENG retained its artery-like mechanical characteristics after two weeks in vivo. These short-term results demonstrate potential advantages of mechanically tuned biomimetic vascular grafts over standard ePTFE grafts. STATEMENT OF SIGNIFICANCE: Off-the-shelf synthetic vascular grafts are often the only option available for treating advanced stages of vascular disease. Despite significant efforts devoted to improving their biochemical characteristics, synthetic peripheral arterial grafts continue to demonstrate poor clinical outcomes leading to costly reinterventions. Here, we hypothesized that a synthetic vascular graft with elastomeric mechanical properties tuned to a healthy peripheral artery promotes better healing responses than a synthetic stiff graft. To test this hypothesis, we developed an Elastomeric Nanofibrillar Graft (ENG) with artery-tuned mechanical properties and compared its performance to a commercial ePTFE graft in a preclinical porcine iliac artery model. Our results suggest that mechanically tuned ENGs can offer better healing responses, potentially leading to better clinical outcomes for peripheral arterial repairs.
Topics: Animals; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Iliac Artery; Nanofibers; Polytetrafluoroethylene; Swine
PubMed: 33549808
DOI: 10.1016/j.actbio.2021.01.047 -
European Journal of Vascular and... Jul 2016Iliac endofibrosis is a rare condition that may result in a reduction of blood flow to the lower extremity in young, otherwise healthy individuals. The data to inform...
OBJECTIVE
Iliac endofibrosis is a rare condition that may result in a reduction of blood flow to the lower extremity in young, otherwise healthy individuals. The data to inform everyday clinical management are weak and therefore a Delphi consensus methodology was used to explore areas of consensus and disagreement concerning the diagnosis and management of patients with suspected iliac endofibrosis.
METHODS
A three-round Delphi questionnaire approach was used among vascular surgeons, sports physicians, sports scientists, radiologists, and clinical vascular scientists with experience of treating this condition to explore diagnosis and clinical management issues for patients with suspected iliac artery endofibrosis. Analysis is based on 18 responses to round 2 and 14 responses to round 3, with agreement reported when 70% of respondents were in agreement.
RESULTS
Initially there was agreement on the typical symptoms at presentation and the need for an exercise test in the diagnosis. Round 3 clarified that duplex ultrasound was a useful tool in the diagnosis of endofibrosis. There was consensus on the most appropriate type of surgery (endarterectomy and vein patch) and that endovascular interventions were inadvisable. The final round helped to inform aspects of the natural history and post-operative surveillance. Progression of the disease was likely with continued exercise but cessation may prevent progression. Surveillance after surgery is generally recommended yearly with at least a clinical assessment.
CONCLUSIONS
There is broad agreement about the presenting symptoms and the investigations required to confirm (or exclude) the diagnosis of iliac endofibrosis. There was consensus on the surgical approach to repair. Disagreement existed about the specific diagnostic criteria that should be applied during non-invasive testing and about post-operative care and resumption of exercise.
Topics: Delphi Technique; Disease Progression; Exercise Test; Fibrosis; Humans; Iliac Artery; Vascular Diseases; Vascular Surgical Procedures
PubMed: 27209899
DOI: 10.1016/j.ejvs.2016.04.004 -
Internal iliac artery preservation strategies in the endovascular treatment of aortoiliac aneurysms.International Angiology : a Journal of... Oct 2018Common iliac aneurysms are present in up to 40% of abdominal aortic aneurysms and frequently impair distal landing zones for endovascular aneurysm repair. Several... (Review)
Review
INTRODUCTION
Common iliac aneurysms are present in up to 40% of abdominal aortic aneurysms and frequently impair distal landing zones for endovascular aneurysm repair. Several techniques have been developed in order to overcome these issues, with different applications and conflicting results. Although long-term outcomes of hypogastric exclusion are favorable, the risks of pelvic ischemia and morbidity rates are high. We aim to review current hypogastric preservation strategies used in the endovascular treatment of aortoiliac aneurysms.
EVIDENCE ACQUISITION
A thorough non-systematic review of the literature was conducted using PubMed/Medline. Forty-five articles were included, according to their scientific relevance and relation with the subject.
EVIDENCE SYNTHESIS
The bell-bottom technique can be used in common iliac arteries with up to 24 mm of diameter. Although apparently effective in the short-term, long-term durability is questionable with reported type 1b endoleak rates varying from 3.4-7.8% and high reintervention rates reported. Iliac branches have better long-term outcomes, with 90.4% patency rates and 91.8% freedom from re-intervention at 10 years' follow-up. Nonetheless, its widespread application is limited by complex anatomies and increased costs. Finally, parallel graft techniques are an effective option for hostile anatomies unsuitable for other techniques. Endoleak due to gutter development remains the biggest limitation for its long-term durability and solid evidence regarding its application is still lacking.
CONCLUSIONS
When determining the appropriate hypogastric preservation strategy, several factors should be considered. Anatomic criteria, life expectancy as well as physical and sexual activity are the most important criteria. Procedure complexity and cost should also be accounted for.
Topics: Aortic Aneurysm, Abdominal; Blood Vessel Prosthesis Implantation; Clinical Decision-Making; Endovascular Procedures; Humans; Iliac Aneurysm; Iliac Artery; Postoperative Complications; Risk Factors; Treatment Outcome; Vascular Patency
PubMed: 30001612
DOI: 10.23736/S0392-9590.18.04004-X -
Journal of Vascular Surgery Jan 2023The purpose of the present study was to evaluate the technical and short-term clinical outcomes of internal iliac artery (IIA) reconstruction during endovascular aortic...
OBJECTIVE
The purpose of the present study was to evaluate the technical and short-term clinical outcomes of internal iliac artery (IIA) reconstruction during endovascular aortic repair (EVAR) with in situ laser-assisted fenestration in cases of abdominal aortic aneurysm (AAA) in which the iliac artery is unfit for an internal branched device (IBD).
METHODS
In the present single-institution retrospective study, we analyzed patients with AAAs who had undergone EVAR with in situ laser-assisted fenestration for IIA reconstruction between January 2018 and April 2021. The study included patients with iliac artery anatomy unfit for the use of commercial IBDs. The primary safety end point was freedom from major adverse events and unplanned reinterventions within 30 days. The primary efficacy end point was freedom from IIA restenosis, reintervention, and symptoms due to pelvic ischemia at 1 year after the procedure.
RESULTS
A total of 20 patients requiring IIA reconstruction but with anatomy unfit for IBD placement were treated with in situ laser-assisted fenestration during EVAR for aortoiliac aneurysms during the study period. The mean age of our patients was 72 years, and 90% were men. The technical success rate was 100%. No patient had died within 30 days after the procedure. A suspicious IIA perforation had occurred in one patient, which was treated with an additional covered stent, for a primary safety end point of 95.0%. After a mean follow-up of 11 months, all except for one of the reconstructed IIAs were patent. Three patients reported symptoms of buttock claudication on the IIA occluded side at their 3-month follow-up after the procedure. However, these symptoms had subsided in two of these patients at 6 months. Type II endoleaks without sac expansion had occurred in two patients owing to retrograde blood flow from the inferior mesenteric artery and lumbar artery. Both patients were kept under close surveillance. The rate of freedom from major adverse events and unplanned reinterventions within 30 days (primary efficacy end point) was 86.3% at 1 year after procedure.
CONCLUSIONS
In situ laser-assisted fenestration was found to be a safe and effective alternative method for IIA reconstruction during EVAR for aortoiliac aneurysms in patients with anatomy unfit for IBD.
Topics: Male; Humans; Aged; Female; Iliac Artery; Blood Vessel Prosthesis; Iliac Aneurysm; Endovascular Aneurysm Repair; Blood Vessel Prosthesis Implantation; Retrospective Studies; Endovascular Procedures; Treatment Outcome; Stents; Aortic Aneurysm, Abdominal; Aorta, Abdominal
PubMed: 35944730
DOI: 10.1016/j.jvs.2022.07.174 -
European Journal of Vascular and... May 2022The aims of the present study were to assess the relative proportion of collagen and elastin in the arterial wall and to evaluate the collagen microstructure from the...
OBJECTIVE
The aims of the present study were to assess the relative proportion of collagen and elastin in the arterial wall and to evaluate the collagen microstructure from the aortic root to the external iliac artery.
METHODS
Arterial wall tissue samples sampled during post-mortem examination from 16 sites in 14 individuals without aneurysm disease were fixed and stained for collagen and elastin. Stained sections were imaged and analysed to calculate collagen and elastin content as a percentage of overall tissue area. Scanning electron microscopy was used to quantify the collagen microstructure at six specific arterial regions.
RESULTS
From the aortic root to the level of the suprarenal aorta, the percentages (area fractions) of collagen (ascending, descending, and suprarenal aorta respectively with 95% confidence interval [CI] 37.5%, 31.7 - 43.2; 38.9%, 33.1 - 44.7; 44.8%, 37.4 - 52.1) and elastin (43.0%, 37.3 - 48.8; 40.3%, 34.8 - 46.1; 32.4%, 25.2 - 39.6) in the aortic wall were similar. From the suprarenal aorta to the internal iliac arteries, the percentage of collagen increased (abdominal aorta, common and internal iliac arteries and external iliac artery respectively with 95% CI 50.6%, 42.7 - 58.7; 51.2%, 45.5 - 56.9; 49.2%, 42.0 - 56.4) reaching a double percentage for elastin (23.6%, 15.7 - 31.6; 20.8%, 15.1 - 26.5; 22.2%, 14.9 - 29.5). Mean collagen fibre diameter (MFD) and average segment length (ASL) were significantly larger in the external iliac artery (MFD 6.03, 95% CI 5.95 - 6.11; ASL 22.21, 95% CI 20.80 - 23.61) than in the ascending aorta (MFD 5.81, 5.72 - 5.89; ASL 19.47, 18.07 - 20.88) and the abdominal aorta (MFD 5.92, 5.84 - 6.00; ASL 21.10, 19.69 - 22.50).
CONCLUSION
In subjects lacking aneurysmal disease, the aorta and iliac arteries are not structurally uniform along their length. There is an increase in collagen percentage and decrease in elastin percentage progressing distally along the aorta. Mean collagen fibre diameter and average segment length are larger in the external iliac artery, compared with the ascending and the abdominal aorta.
Topics: Aorta, Abdominal; Collagen; Elastin; Extracellular Matrix; Humans; Iliac Artery
PubMed: 35346566
DOI: 10.1016/j.ejvs.2022.02.005