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

Endovascular Treatment of Ruptured Thoracic Aortic Aneurysm in Patients Older than 75 Years

AbstractObjectivesTo investigate the outcomes of thoracic endovascular aortic repair (TEVAR) for ruptured descending thoracic aortic aneurysm (rDTAA) in patients older than 75 years.MethodsWe retrospectively identified all patients treated with TEVAR for rDTAA at seven referral centres between 2002 and 2009. The cohort was stratified according to age ≤75 and >75 years, and the outcomes after TEVAR were compared between both groups.ResultsNinety-two patients were identified of which 73% (n = 67) were ≤75 years, and 27% (n = 25) were older than 75 years. The 30-day mortality was 32.0% in patients older than 75 years, and 13.4% in the remaining patients (p = 0.041). Patients older than 75 years suffered more frequently from postoperative stroke (24.0% vs. 1.5%, p = 0.001) and pulmonary complications (40.0% vs. 9.0%, p = 0.001). The aneurysm-related survival after 2 years was 52.1% for patients >75 years, and 83.9% for patients ≤75 years (p = 0.006).ConclusionsEndovascular treatment of rDTAA in patients older than 75 years is associated with an inferior outcome compared with patients younger than 75 years. However, the mortality and morbidity rates in patients above 75 years are still acceptable. These results may indicate that endovascular treatment for patients older than 75 years with rDTAA is worthwhile

Dynamics of the aorta and its sidebranches : implications for endovascular treatment of aortic disease

The main objective of this thesis is to critically evaluate the clinical results of emerging aortic endovascular therapies and then to utilize dynamic imaging modalities [EKG gated dynamic computerized tomographic angiography (CTA) and magnetic resonance angiography (MRA)] to understand the limitations of these technologies and potential source of any complications. The first published mid-term results of aneurysm repair with fenestrated and branched endografts from a European center of excellence is described in Chapter 2. The use of fenestrated and branched devices for difficult re-operative aortic surgery as a salvage procedure was examined in Chapter 3. These two clinical trials revealed new complications specific to fenestrated and branched devices. For example, fractured or bent side-branches and occluded renal branch vessels were observed. The potential of repeated dynamic stresses related to the cardiac cycle was postulated as a source of the problems. The dynamic effect of placing a relatively stiff endograft into a compliant, pulsatile aorta was examined in Chapter 4 through EKG-gated cine CTA. The cardiac based dynamics of the aorta was confirmed in a separate cohort of patients in Chapter 5 using the different modality of EKG-gated cine MRA. Furthermore, stent-graft design specific differences in compliance of the aorta and endograft were noted following EVAR. The renal arteries are the most commonly preserved aortic branch vessels using a fenestrated or branched technique. Furthermore, the complications identified in the fenestrated and branched clinical papers were typically related to the renal arteries. Therefore, we focused our attention on the effects of EVAR on renal artery motion in Chapter 6. Based on earlier work noting differences in stent-graft design on aortic dynamics, we evaluated the effect of three stent-graft designs (infra-re-nal fixation, supra-renal fixation, and branched) on renal artery motion in Chapter 7. Clinicians are increasingly placing thoracic endografts for 'off-label' indications such as traumatic aortic rupture in an effort to provide a less invasive and more effective treatment for these seriously injured poly-trauma patients. Chapter 8 is a systematic analysis of anatomic factors which may predict the rare, potentially devastating complication of thoracic endoprosthesis collapse. Based in part on dynamic CT imaging of thoracic endoprosthesis collapse outlined in Chapter 8, an examination of normal descending aortic pulsatility was undertaken. The results are presented in Chapter 9 and provide insight into the local environment into which these thoracic stent-grafts are being placed. Chapter 10 provides a summary of the most important findings

Meta-analysis of open versus endovascular repair for ruptured descending thoracic aortic aneurysm

Introduction: Ruptured descending thoracic aortic aneurysm (rDTAA) is associated with high mortality rates. Data supporting endovascular thoracic aortic aneurysm repair (TEVAR) to reduce mortality compared with open repair are limited to small series. We investigated published reports for contemporary outcomes of open and endovascular repair of rDTAA. Methods: We systematically reviewed all studies describing the outcomes of rDTAA treated with open repair or TEVAR since 1995 using MEDLINE, Cochrane Library CENTRAL, and Excerpta Medica Database (EMBASE) databases. Case reports or studies published before 1995 were excluded. All articles were critically appraised for relevance, validity, and availability of data regarding treatment outcomes. All data were systematically pooled, and meta-analyses were performed to investigate 30-day mortality, myocardial infarction, stroke, and paraplegia rates after both types of repair. Results: Original data of 224 patients (70% male) with rDTAA were identified: 143 (64%) were treated with TEVAR and 81 (36%) with open repair. Mean age was 70 \ub1 5.6 years. The 30-day mortality was 19% for patients treated with TEVAR for rDTAA compared 33% for patients treated with open repair, which was significant (odds ratio [OR], 2.15, P = .016). The 30-day occurrence rates of myocardial infarction (11.1% vs 3.5%; OR, 3.70, P < .05), stroke (10.2% vs 4.1%; OR, 2.67; P = .117), and paraplegia (5.5% vs 3.1%; OR, 1.83; P = .405) were increased after open repair vs TEVAR, but this failed to reach statistical significance for stroke and paraplegia. Five additional patients in the TEVAR group died of aneurysm-related causes after 30 days, during a median follow-up of 17 \ub1 10 months. Follow-up data after open repair were insufficient. The estimated aneurysm-related survival at 3 years after TEVAR was 70.6%. Conclusion: Endovascular repair of rDTAA is associated with a significantly lower 30-day mortality rate compared with open surgical repair. TEVAR was associated with a considerable number of aneurysm-related deaths during follow-up

Anatomic factors associated with acute endograft collapse after Gore TAG treatment of thoracic aortic dissection or traumatic rupture.

OBJECTIVE: The potentially devastating complication of total or near total thoracic endoprosthesis collapse has been described with the TAG device (W. L. Gore & Associates, Flagstaff, Ariz). This rare complication has resulted in a warning to clinicians and speculation about the etiology of this problem. This report evaluates potential causative anatomic factors that may increase the probability of endoprosthesis collapse in patients undergoing endovascular thoracic aneurysm repair (TEVAR). METHODS: Preoperative and postoperative computed tomography scans were collected worldwide representing six patients who had experienced radiologically confirmed TAG endoprosthesis collapse. These were compared with a matched cohort of five patients with a TAG endoprosthesis in the same anatomic position in which no collapse occurred. Anatomic variables of aortic arch angulation, apposition, intraluminal lip length, proximal aortic diameter, distal aortic diameter, intragraft aortic diameter, percentage of oversizing, and angle of the proximal endograft to the aortic arch were compared between groups. Differences between groups were determined using the Student t test, with P <.05 considered significant. RESULTS: The two groups (collapse vs no collapse) were evenly matched demographically, and all underwent endoluminal treatment with the TAG device, with no differences in gender, graft position in the aorta, operative indication, or age (P = NS). Distal sealing zone aortic diameter +/- standard deviation of 18.9 +/- 1.7 mm vs 22.7 +/- 2.7 mm and minimum aortic diameter within the endograft of 18.6 +/- 1.7 mm vs 22.4 +/- 3.1 mm predicted collapse (P <.05). Proximal aortic diameter, apposition, intraluminal lip length, aortic arch angle, and angle of proximal endograft to aortic arch did not predict collapse (P = NS). CONCLUSION: Thoracic endograft collapse is an exceedingly rare event. In this series, endoprosthesis collapse occurred in patients who were treated outside the manufacturer's instructions for use for minimum required aortic diameter. Although distal aortic diameter and minimum intragraft aortic diameter predicted collapse, other variables may also influence this complication but were not significant owing to potential type II statistical errors. In the future, caution should be exercised when contemplating TEVAR in patients with small