Oversizing of Aortic Stent Grafts for Abdominal Aneurysm Repair: A Systematic Review of the Benefits and Risks

Objective: Sizing of aortic endografts is an essential step in successful endovascular treatment of aortic pathology, although consensus regarding the optimal sizing strategy is lacking. Some proximal oversizing is necessary to obtain a seat between the stent graft and the aortic watt and to prevent the graft from migrating, but excessive oversizing might influence the results negatively. In this systematic review, we investigated the current literature to obtain an overview of the risks and benefits of oversizing and to determine the optimal degree of oversizing of stent grafts used for endovascular abdominal aortic aneurysm repair. Methods: PUBMED, EMBASE and Cochrane Library databases were searched for articles related to the impact of proximal endograft oversizing on complications after endovascular aneurysm repair. After in- and exclusion, 23 relevant articles reporting on 8415 patients remained for analysis and critical appraisal. Results: Most studies that investigated neck dilatation are flawed by poor methodology. No clear relationship between proximal oversizing and neck dilatation relative to the first postoperative scan was found. None of the studies described a positive relationship between the degree of oversizing and the incidence of endoleaks. On the contrary, oversizing up to 25% seems to decrease the risk of proximal endoleaks. There are conflicting data regarding the risk of graft migration when oversizing by more than 30%. Conclusions: Based on the best available evidence, the current standard of 10-20% oversizing regime appears to be relatively safe and preferable. Oversizing >30% might negatively impact the outcome after EVAR. Studies of higher quality are needed to further assess the relationship between proximal oversizing and the incidence of complications, particularly regarding the impact on aneurysm neck dilatation. (C) 2009 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved

Variation in Surgical Treatment of Abdominal Aortic Aneurysms With Small Aortic Diameters in the Netherlands

Objective: To evaluate reasons to deviate from aneurysm diameter thresholds, and focus on the difference in how Dutch vascular surgical units (VSUs) perceive their deviation and their actual deviation. Background: Guidelines recommend surgical treatment for asymptomatic abdominal aortic aneurysms (AAAs) with a diameter of at least 55 mm for men and 50 mm for women. We evaluate reasons to deviate from these guidelines, and focus on the difference in how Dutch vascular surgical units (VSUs) perceive their deviation and their actual deviation. Methods: All patients undergoing elective AAA repair between 2013 and 2016 registered in the Dutch Surgical Aneurysm Audit (DSAA) were included. Surgery at diameters of <55 mm for men and <50 mm for women were considered guideline deviations. National deviation and hospital variation in deviation were evaluated over time. Questionnaires were distributed among all Dutch VSUs, inquiring for acceptable reasons for guideline deviation. VSUs were asked to estimate the guideline deviation percentage in their hospital which was then compared with their DSAA percentage. Results: In all, 9039 patients were included. In 15%, we found guideline deviation, varying from 2% to 40% between VSUs. Over time, 21 VSUs were identified with a lower percentage of deviation than the national mean each year and 8 VSUs with a higher percentage. 44/60 VSUs completed the questionnaire. Most commonly reported reasons to deviate were concomitant large iliac diameter (91%) and saccular aneurysm (82%). The majority of the VSUs (77%) estimated their guideline deviation to be <5%. Eleven VSUs (25%) estimated their deviation concordant with their DSAA percentage, but 75% of VSUs underestimated their deviation. Conclusions: Dutch VSUs regularly deviate from the guidelines regarding aneurysm diameter, with variation between VSUs. Consensus exists amongst VSUs on acceptable reasons for guideline deviations; however, the majority underestimates their actual deviation percentage

Assessment of CardiOvascular Remodelling following Endovascular aortic repair through imaging and computation: the CORE prospective observational cohort study protocol

Thoracic aortic stent grafts are orders of magnitude stiffer than the native aorta. These devices have been associated with acute hypertension, elevated pulse pressure, cardiac remodelling and reduced coronary perfusion. However, a systematic assessment of such cardiovascular effects of thoracic endovascular aortic repair (TEVAR) is missing. The CardiOvascular Remodelling following Endovascular aortic repair (CORE) study aims to (1) quantify cardiovascular remodelling following TEVAR and compare echocardiography against MRI, the reference method; (2) validate computational modelling of cardiovascular haemodynamics following TEVAR using clinical measurements, and virtually assess the impact of more compliant stent grafts on cardiovascular haemodynamics; and (3) investigate diagnostic accuracy of ECG and serum biomarkers for cardiac remodelling compared to MRI

Outcomes in octogenarians and the effect of comorbidities after intact abdominal aortic aneurysm repair in the Netherlands: a nationwide cohort study

Objective: Age is an independent risk factor for mortality after both elective open surgical repair (OSR) and endovascular aneurysm repair (EVAR). As a result of an ageing population, and the less invasive nature of EVAR, the number of patients over 80 years (octogenarians) being treated is increasing. The mortality and morbidity following aneurysm surgery are increased for octogenarians. However, the mortality for octogenarians who have either low or high peri-operative risks remains unclear. The aim of this study was to provide peri-operative outcomes of octogenarians vs. non-octogenarians after OSR and EVAR for intact aneurysms, including separate subanalyses for elective and urgent intact repair, based on a nationwide cohort. Furthermore, the influence of comorbidities on peri-operative mortality was examined.Methods: All patients registered in the Dutch Surgical Aneurysm Audit (DSAA) undergoing intact AAA repair between 2013 and 2018, were included. Patient characteristics and peri-operative outcomes (peri-operative mortality, and major complications) of octogenarians vs. non-octogenarians for both OSR and EVAR were compared using descriptive statistics. Multivariable logistic regression analyses were used to examine whether age and the presence of cardiac, pulmonary, or renal comorbidities were associated with mortality.Results: This study included 12 054 EVAR patients (3 015 octogenarians), and 3 815 OSR patients (425 octogenarians). Octogenarians in both the EVAR and OSR treatment groups were more often female and had more comorbidities. In both treatment groups, octogenarians had significantly higher mortality rates following intact repair as well as higher major complication rates. Mortality rates of octogenarians were 1.9% after EVAR and 11.8% after OSR. Age >= 80 and presence of cardiac, pulmonary, and renal comorbidities were associated with mortality after EVAR and OSR.Conclusion: Because of the high peri-operative mortality rates of octogenarians, awareness of the presence of comorbidities is essential in the decision making process before offering aneurysm repair to this cohort, especially when OSR is considered.Development and application of statistical models for medical scientific researc

Dynamics of Endovascular Eneurysm Repair

Endovascular aneurysm repair (EVAR) was in 1996 started at the St. Antonius Hospital, Nieuwegein, The Netherlands, with use of the AneuRx stent-graft system (Medtronic AVE, Santa Rosa, CA, USA). All data were captured prospectively in a vascular database. In Chapter 2 a general overview of recent literature of EVAR is evaluated. Chapter 3 contains mid-term single-center results with the AneuRx device in the first 77 patients with a minimum follow-up of 12 months. In Chapter 4, the application of EVAR to repair paraanastomotic aneurysms (PAA's) is described. In our series of 14 patients, PAA's were successfully excluded with EVAR without perioperative mortality and with morbidity in one patient. Median follow-up was 12 months. In patients who were treated with bifurcated stent-grafts, no conversions were performed, and a secondary intervention was necessary in one patient. Reconstructions of proximal aortic anastomotic aneurysms with endovascular tube grafts were not durable, however. In Chapter 5, stent-graft explantation is discussed. In our series of 355 patients treated with stent-grafts, late conversion rate was 3.1%. Mortality rate for acute conversions was 50%. Of the six patients who needed elective conversion, mortality rate was 0% and morbidity rate was 67%; These results advocate timely explantation if EVAR-related problems occur cannot be solved with endovascular techniques. Chapter 6 focuses on the long-term single-center results with the AneuRx device which was used in 212 patients. Perioperative mortality rate was 2.4 %. Freedom from secondary interventions was 48% at 9 years. The aneurysm-related death rate was relatively small, with an annual risk of about 1%. Most secondary interventions were needed for fixation-related problems in the proximal aortic anchoring zone. Therefor we decided to start dynamic studies on the area of the proximal aortic neck by means of dynamic magnetic resonance angiography (MRA). Chapter 7 describes a study on dynamics of the proximal anchoring zone studied with dynamic MRA before and after EVAR in 11 patients. Preoperatively, mean diameter changes at each level were about 8%. These diameter changes differed between patients and even within each patient they varied over the studied axes. Pulsatility of the aneurysm neck appeared not to be influenced by stent-graft placement. In Chapter 8, wall stiffness of the aneurysm neck and the aneurysm sac were studied with dynamic MRA, before and after stent-graft placement in 11 patients. We measured an increased stiffness at the level of the aneurysm sac after EVAR Neither EVAR nor endoleaks resulted in changes of stiffness within the aneurysm neck. Stent-graft design did influence compliance at the level of the neck. Conclusion This thesis has shown acceptable results during mid-term and long-term follow-up for patients with severe comorbidities. Proximal fixation of the stent-graft was identified as the Achilles' heel of EVAR and therefore should be of major interest for further investigation and improvement. We presented new information on dynamic features of the aneurysm neck before and after stent-graft placement. This information gains insight into a whole new area for further studies and will have its effects on inclusion criteria and stent-graft designs

Dynamics of Endovascular Eneurysm Repair

Endovascular aneurysm repair (EVAR) was in 1996 started at the St. Antonius Hospital, Nieuwegein, The Netherlands, with use of the AneuRx stent-graft system (Medtronic AVE, Santa Rosa, CA, USA). All data were captured prospectively in a vascular database. In Chapter 2 a general overview of recent literature of EVAR is evaluated. Chapter 3 contains mid-term single-center results with the AneuRx device in the first 77 patients with a minimum follow-up of 12 months. In Chapter 4, the application of EVAR to repair paraanastomotic aneurysms (PAA's) is described. In our series of 14 patients, PAA's were successfully excluded with EVAR without perioperative mortality and with morbidity in one patient. Median follow-up was 12 months. In patients who were treated with bifurcated stent-grafts, no conversions were performed, and a secondary intervention was necessary in one patient. Reconstructions of proximal aortic anastomotic aneurysms with endovascular tube grafts were not durable, however. In Chapter 5, stent-graft explantation is discussed. In our series of 355 patients treated with stent-grafts, late conversion rate was 3.1%. Mortality rate for acute conversions was 50%. Of the six patients who needed elective conversion, mortality rate was 0% and morbidity rate was 67%; These results advocate timely explantation if EVAR-related problems occur cannot be solved with endovascular techniques. Chapter 6 focuses on the long-term single-center results with the AneuRx device which was used in 212 patients. Perioperative mortality rate was 2.4 %. Freedom from secondary interventions was 48% at 9 years. The aneurysm-related death rate was relatively small, with an annual risk of about 1%. Most secondary interventions were needed for fixation-related problems in the proximal aortic anchoring zone. Therefor we decided to start dynamic studies on the area of the proximal aortic neck by means of dynamic magnetic resonance angiography (MRA). Chapter 7 describes a study on dynamics of the proximal anchoring zone studied with dynamic MRA before and after EVAR in 11 patients. Preoperatively, mean diameter changes at each level were about 8%. These diameter changes differed between patients and even within each patient they varied over the studied axes. Pulsatility of the aneurysm neck appeared not to be influenced by stent-graft placement. In Chapter 8, wall stiffness of the aneurysm neck and the aneurysm sac were studied with dynamic MRA, before and after stent-graft placement in 11 patients. We measured an increased stiffness at the level of the aneurysm sac after EVAR Neither EVAR nor endoleaks resulted in changes of stiffness within the aneurysm neck. Stent-graft design did influence compliance at the level of the neck. Conclusion This thesis has shown acceptable results during mid-term and long-term follow-up for patients with severe comorbidities. Proximal fixation of the stent-graft was identified as the Achilles' heel of EVAR and therefore should be of major interest for further investigation and improvement. We presented new information on dynamic features of the aneurysm neck before and after stent-graft placement. This information gains insight into a whole new area for further studies and will have its effects on inclusion criteria and stent-graft designs

Endovascular treatment of internal iliac artery stenosis in patients with buttock claudication

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Potential value of aneurysm sac volume measurements in addition to diameter measurements after endovascular aneurysm repair.

Item does not contain fulltextPURPOSE:To investigate the value of aneurysm sac volume measurement in addition to diameter measurements based on computed tomographic angiography (CTA) after endovascular aneurysm repair (EVAR). METHODS:Interrogation of a vascular database identified 56 patients (51 men; median age 77 years, range 59-92), 28 with an endoleak and 28 without, who had digital CTA data available at baseline (first postoperative scan) and at 1 and 2 years after EVAR. Total aneurysm volume, transverse maximum diameter (TMD), and orthogonal maximum diameter (OMD; perpendicular to the aortic center lumen line) were compared for all patients and between those with and without endoleak. Differences of 5% for volume and 5 mm for diameters were considered a significant change. Kappa statistics were used to compare measurements. RESULTS:Volumetry detected aneurysm growth in 32 (24%) of 131 scans, which was reflected by TMD in 12 (38%) and by OMD in 14 (44%). Eighteen scans with increasing aneurysm volume were measured in patients with endoleaks, which was documented by TMD in 6 (33%) and by OMD in 8 (44%). Fourteen volume increases were measured in patients without endoleak; both TMD and OMD documented only 43%. Volumetry detected aneurysm shrinkage in 71 (54%) of 131 scans [detected by TMD in 38 (54%) and by OMD in 37 (52%)]. Thirty-two volume decreases were measured in patients with an endoleak, noted by TMD in 18 (56%) and OMD in 14 (44%). Thirty-nine scans showed decreasing volumes in patients without endoleaks; the TMD corresponded in 20 (51%) and the OMD in 23 (59%). The kappa agreements for volume increase were 0.42 (TMD) and 0.35 (OMD) and for volume decrease 0.48 (TMD) and 0.47 (OMD); different thresholds of change produced similar moderate-range kappa values (0.3-0.6). CONCLUSION:Volumetry detects sac size changes that are not reflected in diameter measurements. Vice versa, diameters can increase without a total volume increase, which might indicate a variety of morphological aneurysm changes. The agreement between volume and diameter measurements using different cutoff values is equally moderate. Volume measurements should be performed in addition to diameter measurements