Potential impact of therapeutic warfarin treatment on type II endoleaks and sac shrinkage rates on midterm follow-up examination

Systematic Review and Meta-Analysis of the Effect of Anticoagulation on Outcomes After Endovascular Aneurysm Repair

PURPOSE

Our objective was to investigate whether patients who receive anticoagulation therapy have different outcomes after endovascular aneurysm repair (EVAR) from those who do not.

MATERIALS AND METHODS

We conducted a systematic review of studies that compared outcomes of EVAR in patients who were on therapeutic anticoagulation vs those who were not. We developed and reported the review in accordance with the PRISMA guidelines with a registered protocol (CRD42022375894). The Ovid interface was used to search Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica Database (EMBASE), and Cochrane Central Register of Controlled Trials (CENTRAL) up to November 2022. The quality of studies was assessed with the Newcastle-Ottawa Scale (NOS) (maximum score=9), and the evidence was appraised with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. The hazard ratio (HR) and 95% confidence interval (CI) was the effect estimate in time-to-event meta-analyses, calculated using the inverse-variance statistical method and random-effects models.

RESULTS

Sixteen studies qualified for inclusion reporting a total of 35 739 individuals. Anticoagulated patients had a statistically significantly higher hazard of death (HR=1.93, 95% CI=1.03-3.63), endoleak (HR=2.13, 95% CI=1.55-2.93), reintervention (HR=1.79, 95% CI=1.27-2.52), and aneurysm sac expansion (HR=2.72, 95% CI=1.57-4.72) than patients not receiving anticoagulation therapy. The median score on the NOS was 7 (range=4-9). The certainty of evidence was very low for mortality and reintervention and low for endoleak and sac expansion.

CONCLUSIONS

Anticoagulation is a poor prognostic factor after standard EVAR and should be considered in decision-making, consent processes, and surveillance strategies.

CLINICAL IMPACT

The number of individuals who take anticoagulation treatment has been rapidly increasing over the recent years. We aimed to investigate the effect of such treatment on outcomes after endovascular aneurysm repair (EVAR). Anticoagulated patients were found to have increased mortality, endoleak, and reintervention rates after EVAR compared to their non-anticoagulated counterparts. Anticoagulation therapy has a prognostic role in EVAR and should be considered in decision making and EVAR surveillance. Anticoagulated patients need to be informed of the higher failure rates of EVAR, and intensified surveillance strategies may need to be implemented in this patient cohort.

Outcomes and Economic Impact of Hypogastric Artery Management During Elective Endovascular Aortic Repair for Aorto-Iliac Aneurysms

BACKGROUND

To analyze clinical outcomes and perform a macro-costing evaluation of endovascular aortic repair (EVAR) for aorto-iliac aneurysms.

METHODS

This is a retrospective, financially unsupported, physician-initiated observational cohort study. Patients with iliac artery involvement treated with EVAR between January 1st, 2014 and December 31st, 2021 were identified. Inclusion criteria were intact aneurysm, elective EVAR with at least 1 hypogastric artery (HA) treatment, use of bifurcated endograft (EG), and at least 6 months of follow-up. Primary outcomes of interest were overall survival, freedom from aneurysm-related mortality (ARM), freedom from EVAR-related reintervention, and overall EVAR(procedure)-related costs.

RESULTS

We studied 122 (9.1%) patients: 119 (97.5%) were male and 3 (2.5%) females. Median age of patients was 76 years (range, 68.75-81). Overall, 107 (87.7%) patients had both HAs preserved according to following strategy: 45 (36.9%) with flared limbs, 13 (10.6%) with bilateral branched device, and 49 (40.2%) with a combination of flared limb on 1 side and branched device on the contralateral side. Bilateral overstenting was performed in 15 (12.3%) patients. Estimated overall survival was not different between groups of EVAR (Log-rank, P = 0.561). There was only 1 (0.8%) ARM ascertained during the follow-up. Estimated freedom from EVAR-related reintervention was not different among groups (Log-rank, P = 0.464). During the follow-up, 9 (7.4%) patients developed buttock claudication (Society for Vascular Surgery (SVS) grade 1, n = 4, SVS grade 2, n = 5), more frequently in HA overstenting (hazard ratio (HR): 3.6; 95% confidence intervals (CIs): 0.96-13.5, P = 0.058). When all cots were included, branched EVAR still carried the highest burden (P = 0.001) in comparison with the mixed subgroup, the overstenting subgroup, and the flared limbs subgroup.

CONCLUSIONS

Early mortality and pelvic ischemic syndromes rate were acceptably low in all techniques. Hypogastric artery preservation showed lower complication rate in comparison with HA overstenting which, however, appears to be safe an effective for option with similar overall costs for patients who are not candidates for HA preservation based on aortic anatomy.

Antithrombotic Therapy for Aortic Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVES

The role of antithrombotic therapy in the management of aortic and peripheral aneurysms is unclear. This systematic review and meta-analysis aimed to assess the impact of antithrombotics on clinical outcomes for aortic and peripheral aneurysms.

METHODS

Medline, Embase, and CENTRAL databases were searched. Randomised controlled trials and observational studies investigating the effect of antithrombotic therapy on clinical outcomes for patients with any aortic or peripheral artery aneurysm were included.

RESULTS

Fifty-nine studies (28 with antiplatelet agents, 12 anticoagulants, two intra-operative heparin, and 16 any antithrombotic agent) involving 122 102 patients were included. Abdominal aortic aneurysm (AAA) growth rate was not significantly associated with the use of antiplatelet therapy (SMD -0.36 mm/year; 95% CI -0.75 - 0.02; p = .060; GRADE certainty: very low). Antithrombotics were associated with increased 30 day mortality for patients with AAAs undergoing intervention (OR 2.30; 95% CI 1.51 - 3.51; p < .001; GRADE certainty: low). Following intervention, antiplatelet therapy was associated with reduced long term all cause mortality (HR 0.84; 95% CI 0.76 - 0.92; p < .001; GRADE certainty: moderate), whilst anticoagulants were associated with increased all cause mortality (HR 1.64; 95% CI 1.14 - 2.37; p = .008; GRADE certainty: very low), endoleak within three years (OR 1.99; 95% CI 1.10 - 3.60; p = .020; I² = 60%; GRADE certainty: very low), and an increased re-intervention rate at one year (OR 3.25; 95% CI 1.82 - 5.82; p < .001; I² = 35%; GRADE certainty: moderate). Five studies examined antithrombotic therapy for popliteal aneurysms. Meta-analysis was not possible due to heterogeneity.

CONCLUSIONS

There was a lack of high quality data examining antithrombotic therapy for patients with aneurysms. Antiplatelet therapy was associated with a reduction in post-intervention all cause mortality for AAA, whilst anticoagulants were associated with an increased risk of all cause mortality, endoleak, and re-intervention. Large, well designed trials are still required to determine the therapeutic benefits of antithrombotic agents in this setting.

Anticoagulation and Antiplatelet Medications Do Not Affect Aortic Remodeling after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

OBJECTIVE

There is a lack of evidence regarding the effect of anticoagulation and antiplatelet medications on aortic remodeling for aortic dissection after endovascular repair. We investigated whether anticoagulation and antiplatelet medications affect aortic remodeling after thoracic endovascular aortic repair (TEVAR) for Type B aortic dissection (TBAD).

METHODS

Records of the Vascular Quality Initiative TEVAR registry (2012-2020) were reviewed. Procedures performed for TBAD were included. Aortic reintervention, false lumen thrombosis of the treated aorta and all-cause mortality at follow-up were compared between patients treated with and without anticoagulation medications. A secondary analysis was performed to assess the effect of antiplatelet therapy in patients not on anticoagulation. Cox proportional hazards models were used to estimate the effect of anticoagulation and antiplatelet therapies on outcomes.

RESULTS

1,210 patients (mean age, 60.7±12.2 years; 825 (68%) males) were identified with a mean follow-up of 21.2±15.7 months (range 1-94 months). 166 (14%) patients were on anticoagulation medications at discharge and at follow-up. Patients on anticoagulation were more likely to be older (mean age, 65.5 vs 60 years; P<.001) and Caucasian (69% vs 55%; P=.003), with higher proportions of coronary artery disease (10% vs 3%; P<.001), congestive heart failure (10% vs 2%; P<.001) and chronic obstructive pulmonary disease (15% vs 9%; P=.017). There were no differences in the mean preoperative thoracic aortic diameter or the number of endografts used. At 18-month, the rates of aortic reinterventions (8% vs 9% log-rank P=.873), complete false lumen thrombosis (52% vs 45%; P=.175) and mortality (2.5% vs 2.7%; P=.209) were similar in patients with and without anticoagulation, respectively. Controlling for covariates with the Cox regression method, anticoagulation use was not independently associated with a decreased rates of complete false lumen thrombosis (hazard ratio (HR) 0.74; 95% confidence interval (CI), 0.5-1.1; P=.132), increased need for aortic reinterventions (HR 1.02; 95% CI, 0.62-1.68; P=.934), and mortality (HR 1.25; 95% CI, 0.64-2.47; P=.514). On a secondary analysis, antiplatelet medications did not affect the rates of aortic reintervention, complete false lumen thrombosis and mortality.

CONCLUSIONS

Anticoagulation and antiplatelet medications do not appear to negatively influence the midterm endpoints of aortic reintervention or death in patients undergoing TEVAR for TBAD. Moreover, it did not impair complete false lumen thrombosis. Anticoagulation and antiplatelet medications do not adversely affect aortic remodeling and survival in this population at midterm.

The fate of endoleaks after endovascular aneurysm repair and the impact of oral anticoagulation on their persistence

BACKGROUND

The impact of anticoagulation on late endoleaks after endovascular aneurysm repair (EVAR) is unclear despite multiple investigators studying the relationship. The purpose of this study was to determine if long-term anticoagulation impacted the development of late endoleaks and if specific anticoagulants were more likely to exacerbate the development of endoleaks.

METHODS

Using the Society for Vascular Surgery Vascular Quality Initiative database, patients undergoing EVAR between 2003 and 2019 for abdominal aortic aneurysms were evaluated. Patients were divided into two groups: those without a late endoleak and those with a late endoleak. Bivariate analysis was performed to assess preoperative, intraoperative, postoperative, and long-term follow-up variables. A multivariable analysis was done to determine associations of independent variables with late endoleaks. Patients were further subcategorized based on anticoagulation status before and after EVAR, specific type of anticoagulation, and the presence of an index endoleaks (diagnosed at the time of EVAR) to determine the subsequent frequency of late endoleaks.

RESULTS

A total of 29,783 patients were analyzed with 2169 (7.3%) having a late endoleak identified. Several risk factors were related to late endoleaks, including anticoagulation before and after EVAR (odds ratio [OR], 4.23; 95% confidence interval [CI], 2.57-6.96; P < .001), anticoagulation after EVAR (OR, 1.88; 95% CI, 1.43-2.49; P < .001), and index endoleak (OR, 1.45; 95% CI, 1.26-1.66; P < .001). The frequency of late endoleaks in patients anticoagulated before and after EVAR and after EVAR as compared with those never anticoagulated was 16.89% and 14.40% vs 6.95%, respectively (both P > .001). No difference in late endoleaks were noted for patients treated with warfarin and novel oral anticoagulants. The most common type of index and late endoleak identified was type II, but patients with type I, type II, and type IV index endoleaks were more commonly found to have type I, type II, and type IV late endoleaks, respectively. The frequency of late endoleaks in patients with both an index endoleak and anticoagulation after EVAR was 20.42% as compared with patients with only anticoagulation after EVAR (14.63%; P = .0015) and with patients with index endoleaks not anticoagulated (10.06%; P < .00001).

CONCLUSIONS

Late endoleaks were more common in patients treated with anticoagulation after EVAR. No difference in late endoleak frequency was detected between anticoagulation with warfarin and novel oral anticoagulants. Patients on anticoagulation and those with an index endoleak were at a higher risk of having a late endoleak.

Arterial-portal fistula treated with hepatic arterial embolization and portal venous aneurysm stent-graft exclusion complicated by type 2 endoleak

Intrahepatic arterioportal fistulas may be complicated by portal hypertension. An associated portal venous aneurysm (PVA) may impinge upon adjacent structures or rupture. We present a 65-year-old man with an intrahepatic Intrahepatic arterioportal fistula and 6.4 × 5.8 cm right portal vein aneurysm extending within 0.4 cm of the hepatic margin, associated with pain concerning for impending rupture. The PVA was refractory to transarterial embolization due to recruitment of arterial collaterals. Therefore, it was additionally excluded from the portal vein with a 12 mm × 9.5 cm venous stent graft. Although endovascular therapy thrombosed the aneurysm and improved symptoms, it was complicated by a type 2 endoleak into the PVA.

Characteristics and Risk Factors for Type 2 Endoleak in an East Asian Population From a Japanese Multicenter Database

BACKGROUND

Clinically distinct differences exist between East Asian and Caucasian subjects, but data for type 2 endoleak (T2EL) are limited in the East Asian population. The aim of this study was to analyze the characteristics of East Asian T2EL using a Japanese multicenter database.

METHODS AND RESULTS

Retrospective analysis of 832 endovascular aneurysm repairs performed from 2008 to 2014 were conducted. T2EL was observed in 234 cases (28.1%), and in 32 cases (3.8%) it led to sac expansion >5 mm caused by isolated T2EL (median follow-up, 35.6 months). On univariate and multivariate analysis, non-smoker status (odds ratio [OR], 2.216; P<0.001), Excluder stent graft (OR, 2.027; P<0.001), and T2EL at final angiogram (OR, 2.080; P<0.001) were risk factors for T2EL. On multivariate analysis for isolated T2EL with sac expansion, only non-smoker status remained (OR, 2.671; P<0.001). Other than T1EL, isolated T2EL was the most significant risk factor for sac expansion (OR, 18.486; P<0.001). Furthermore, out of 11 transarterial embolization procedures initiated, 4 led to rupture during follow-up.

CONCLUSIONS

East Asian T2EL had a strong relationship with non-smoker status. Also, T2EL was a significant risk factor for sac expansion, which sometimes led to rupture even after intervention. Along with the high prevalence of T2EL observed, East Asian T2EL may not always be benign.

Type 2 Endoleaks Post-EVAR: Current Evidence for Rupture Risk, Intervention and Outcomes of Treatment

Type 2 endoleaks (EL2) are the most commonly encountered endoleaks following EVAR. Despite two decades of experience, there remains considerable variation in the management of EL2 with controversies ranging from if to treat, when to treat and how to treat. Here, we summarise the available evidence, describe the treatment techniques available and offer guidelines for management.

Type II endoleak after endovascular repair of abdominal aortic aneurysm: effectiveness of embolization

The purpose of this study was to report our experience in treating type II endoleaks after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms. Two hundred eighteen patients underwent EVAR with a Zenith stent-graft from January 2000 to December 2005. During a follow-up period of 4.5 + or - 2.3 years, solely type II endoleak was detected in 47 patients (22%), and 14 of them underwent secondary interventions to correct this condition. Ten patients had transarterial embolization, and four patients had translumbar/transabdominal embolization. The embolization materials used were coils, thrombin, gelatin, Onyx (ethylene-vinyl alcohol copolymer), and glue. Disappearance of the endoleak without enlargement of the aneurysm sac after the first secondary intervention was achieved in only five of these patients (5/13). One patient without surveillance imaging was excluded from analyses of clinical success. After additional interventions in four patients and the spontaneous disappearance of type II endoleak in two patients, overall clinical success was achieved in eight patients (8/12). One patient did not have surveillance imaging after the second secondary intervention. Clinical success after the first secondary intervention was achieved in two patients (2/9) in the transarterial embolization group and three patients (3/4) in the translumbar embolization group. The results of secondary interventions for type II endoleak are unsatisfactory. Although the small number of patients included in this study prevents reliable comparisons between groups, the results seem to favor direct translumbar embolization in comparison to transarterial embolization.

Predictive Factors, Morphologic Effects, and Proposed Treatment Paradigm for Type II Endoleaks after Repair of Infrarenal Abdominal Aortic Aneurysms

PURPOSE

To evaluate the predictive factors and outcome of type II endoleaks after endovascular repair of infrarenal abdominal aortic aneurysms with use of a Zenith endograft.

MATERIALS AND METHODS

Patients classified at high risk were enrolled in a prospective study and evaluated with serial cross-sectional imaging techniques. The effect of a type II endoleak on sac behavior and associated factors were analyzed. Type II endoleaks were categorized as absent, persistent, or transient, and the morphologic effects were determined. Logistic regression and classification tree were used to predict which patients may be at risk for persistent type II endoleaks.

RESULTS

A total of 273 patients were enrolled. Patients were excluded in the absence of a minimum of 6 months digital data or the presence of endoleak not classified as type II. Two hundred four patients met inclusion criteria, with a median follow-up period of 24 months (range, 6-60 months). Early type II endoleak was detected in 35 patients (17%), which resolved spontaneously in 17 cases. There were 18 patients with persistent endoleak, 17 patients with transient type II endoleak, and 169 patients with no endoleak. Aneurysm enlargement was detected in seven patients with persistent endoleak (39%), no patients with transient type II endoleak, and one patient with no endoleak. No variables were predictive of the development of persistent endoleak. The relative risk of aneurysmal growth was 77 with persistent endoleak. Successfully treated persistent endoleaks were not associated with any growth.

CONCLUSIONS

Persistent endoleaks are associated with sac growth. Transient type II endoleaks have a benign course and do not require treatment. Successful treatment of persistent endoleak ameliorates the risk of growth.

Reversible endotension associated with excessive warfarin anticoagulation

An aortic aneurysm was successfully treated with an endovascular stent graft, with no evidence of endoleak and documented progressive aortic diameter reduction during the first 23 months. At 29 months, the patient had documented enlargement of the aneurysm sac associated with excessive anticoagulation with warfarin. No evidence of endoleak could be demonstrated with any diagnostic modality. Progressive aneurysm sac diameter regression was documented after reversal of excessive anticoagulation to therapeutic levels (international normalized ratio of 2 to 3). Strict monitoring of coagulation profile in patients after endovascular aneurysm repair requiring anticoagulation with warfarin is recommended to avoid this complication, which to our knowledge has not been previously reported.

An 8-year experience with type II endoleaks: Natural history suggests selective intervention is a safe approach

OBJECTIVE

The treatment of type II endoleaks remains controversial because little is known about their long-term natural history and impact on changes in aneurysm morphology. This study reviews type II endoleaks occurring in patients after endovascular abdominal aortic aneurysm repair (EVAR) at a single-institution over an 8-year period.

METHODS

All patients undergoing EVAR who had type II endoleaks documented on follow-up imaging studies at our institution between January 1997 and March 2005 were reviewed. Data regarding patient demographics in addition to aneurysm size, device type, operative complications, and secondary interventions were reviewed. Outcomes evaluated included the rate of spontaneous sealing, freedom from secondary intervention, and aneurysm enlargement, rupture, or conversion.

RESULTS

Type II endoleaks were present in 154 of 965 patients (16.0%) undergoing EVAR. Mean follow-up time was 22.0 months (range, 1 to 72 months). Fifty-five patients (35.7%) with type II endoleaks sealed spontaneously in a mean time of 14.5 months. According to Kaplan-Meier analysis, approximately 75% of type II endoleaks sealed spontaneously within a 5-year period. Nineteen patients (12.3%) with type II endoleaks were treated at a mean time of 19.9 months at the operating surgeon's discretion, including 13 with sac enlargement >5 mm. Kaplan-Meier analysis estimated that approximately 65% of the patients remained free of intervention after a period of 4 years. Thirteen patients (8.4%) experienced aneurysm sac enlargement >5 mm. Kaplan-Meier analysis estimated that approximately 80% of patients with type II endoleaks remained free of sac enlargement >5 mm over a 4-year period. No patients with type II endoleaks experienced rupture or required conversion to open repair during their follow-up. Cox regression analysis showed that cancer, coronary artery disease, and chronic obstructive pulmonary disease were associated with earlier spontaneous closure of the type II endoleaks (P < .05).

CONCLUSIONS

We observed that type II endoleaks have a relatively benign course, and in the absence of sac expansion, can be followed for a prolonged course of time without the need for intervention. The rate of spontaneous seal continues to increase with time and, therefore, close follow-up of patients with type II endoleaks who show no signs of aneurysm expansion is a safe approach. For patients in whom the exact etiology of their endoleak is in question, dynamic imaging should be used to exclude the presence of a type I endoleak.

Factors predictive of early or late aneurysm sac size change following endovascular repair

OBJECTIVE

The purpose of this study was to determine the relationship between aneurysm sac size change at 1, 6, 12, and 24 months and a set of 10 independent "predictive" variables by using a general linear model analysis.

METHODS

In a multicenter trial, 351 patients received the Zenith tri-modular bifurcated endograft. The predictive variables used for this analysis were endoleak by type, age, gender, smoking status, and the preprocedure variables of maximum aneurysm major diameter, minor neck diameter, proximal neck length, neck plaque/thrombus, and neck shape; and patent inferior mesenteric artery at predischarge. The aneurysm change was calculated as the difference from the predischarge (< or = 7 days of implant) maximum aneurysm major diameter measurement to the maximum aneurysm major diameter measurement at follow-up examination periods of 1, 6, 12, and 24 months. The same 10 predictive variables were used to assess the absolute change in maximum aneurysm minor diameter and aneurysm area. Additionally, the percent change from predischarge was also assessed for the major diameter, minor diameter, and aneurysm area.

RESULTS

None of the independent variables were predictive of absolute sac size change or percent change at 1 month. At 6 months, the presence of an endoleak (P < .01) and preprocedure neck thrombus/plaque (P = .01) were significant predictors of absolute and relative aneurysm size change for all measurements (major diameter, minor diameter, and area) and were more likely to be associated with less sac shrinkage or to have sac growth. Additionally, preoperative maximum aneurysm major diameter was a significant predictor for absolute change in area (P < .01). Larger preprocedure aneurysm diameters were more likely to experience more shrinkage. The significant predictors of size change at 12 months included preprocedure maximum aneurysm major diameter, the presence of endoleak at 12 months, preoperative neck thrombus/plaque, and gender. At 24 months, significant predictors of aneurysm size change included preprocedure maximum aneurysm major diameter, endoleak at 24 months, and preprocedure neck thrombus/plaque. When the longitudinal model was used, the presence of an endoleak, thrombus/plaque within the proximal neck at preprocedure, and preprocedure maximum aneurysm major diameter were found to be significantly related to the size of the maximum aneurysm major diameter over time.

CONCLUSIONS

This study supports the concept that early and late sac size change following EVAR is influenced by identifiable independent predictive variables.

Does Chronic Oral Anticoagulation With Warfarin Affect Durability of Endovascular Aortic Aneurysm Exclusion in a Midterm Follow-up?

PURPOSE

To evaluate the effect of oral anticoagulation on durability of endovascular aortic aneurysm repair (EVAR).

METHODS

Retrospective review was conducted of 182 consecutive EVAR patients (169 men; mean age 75.3 years, range 53-89) between 1999 and 2003. Patients on warfarin anticoagulation (WA, n=21; International Normalized Ratio of 2 to 3) were compared against a control group (CG) with no postoperative anticoagulation (n=161). Death, aneurysm rupture, and reintervention were considered primary endpoints; endoleaks, endograft migration, and aneurysm remodeling were secondary endpoints.

RESULTS

Mean follow-up was 16.3+/-12.6 months. One-year mortality was 6.6% (9.5% WA versus 6.2% CG); overall mortality was 14.3% (p=0.414). No aneurysm rupture occurred. At 1, 2, and 3 years, respectively, cumulative reinterventions (20%/20%/20% WA versus 12%/15%/20% CG; p=0.633) and endoleak rates (25%/25%/25% WA versus 17%/22%/34% CG; p=0.649) were comparable. In both groups, most completion endoleaks resolved (42.9% WA versus 74.4% CG; p=0.474), but few de novo endoleaks did (0% WA versus 12.8% CG; p=0.538). Anticoagulation did not affect mean time to aneurysm sac shrinkage (1.3+/-0.3 WA versus 1.4+/-0.1 years CG; p=0.769).

CONCLUSIONS

After EVAR, anticoagulation appears safe and does not significantly alter mortality, risk for rupture, or the incidence of reintervention. Early endoleaks appear more common in anticoagulated patients, but anticoagulation does not preclude spontaneous endoleak resolution nor does it increase late endoleak rates. Irrespective of the anticoagulation status, early but not late endoleaks usually sealed spontaneously. Observing type II endoleaks appears safe in the absence of aneurysm enlargement.

Perirenal Fixation as an Independent Factor in Aortic Remodeling after Endovascular Aortic Aneurysm Repair

The purpose of our study was to evaluate the influence of perirenal fixation of endovascular aortic grafts on the rate of endoleak and aortic sac remodeling. Retrospective analysis of all patients (pts.) after undergoing endovascular aortic aneurysm repair (EVAR) at our institution was performed. Pre- and postoperative aortic dimensions were obtained from CT scans and angiograms. Intraoperative angiograms were reviewed and patients grouped by the proximity of the graft to the lowest renal arteries: group I: flush with the lowest renal artery; group II: < or = 5 mm distal to lowest renal artery; and group III: >5 mm distal to lowest renal artery. Of the 96 grafts placed between 2000 and 2002, 44 were AneuRx (Medtronic, Santa Rosa, CA) and 52 were Ancure (Guidant, Menlo Park, CA) devices. There were 39 pts. in group I, 42 in group II, and 11 in group III (data on 5 pts. were not obtained). At 6 months, the mean decrease in sac diameter for all groups was 0.42 +/- 0.08 cm (1: 0.56 +/- 0.11 cm; 11: 0.38 +/- 0.11 cm; III: 0.6 +/- 0.15 cm). There was no significant difference between each group. When perirenal fixation (group I) was compared with nonperirenal fixation (groups II and III), there was a significant difference in sac shrinkage at 6 months (p < 0.05, ANOVA). Group I had shorter necks and smaller aneurysms (2.2 +/- 0.1 cm and 5.3 +/- 0.1 cm) than those of groups II and III (2.7 +/- 0.1 cm and 5.7 +/- 0.1 cm, p < 0.05, ANOVA). There was no difference in aortic neck diameter or in aortic neck diameter to graft ratio. When controlled for the variables studied (AAA diameter, length of neck, diameter of neck, diameter of neck to graft ratio, and any endoleak by 6 months), logistic regression analysis identified perirenal fixation as the only significant factor in aortic sac shrinkage of >0.4 cm by 6 months (odds ratio = 16, p < 0.01). With the same variables, a linear regression model also identified perirenal fixation as the only predictive factor in aortic shrinkage (regression coefficient = 0.46, p < 0.05). The endoleak-free survival rate with perirenal fixation was 96 +/- 5% and without it was 80 +/- 7% (Kaplan Meier, p = 0.09, log rank). Perirenal placement of endovascular grafts is associated with a trend toward fewer endoleaks, and improved aortic sac shrinkage independent of aortic neck length, AAA diameter, diameter of neck, and endoleak. Failure to achieve perirenal placement of EVAG increased the likelihood of reduced or failed aortic sac shrinkage in this series.

Is a Type II Endoleak after EVAR a Harbinger of Risk? Causes and Outcome of Open Conversion and Aneurysm Rupture during Follow-up

OBJECTIVE

There is still debate whether type II endoleaks represent a risk for the patient after EVAR. Treatment policies vary from fairly conservative to active intervention. In this analysis risk factors for type II endoleak and adverse events during follow-up were assessed. In addition, risk factors and causes for conversion to open repair and for rupture post-EVAR were studied.

METHODS

The data of 3595 patients, who underwent operation between 1996 and 2002 in 114 European institutions that collaborated in the EUROSTAR Registry, were assessed. To accurately assess the influence of type II endoleaks patients with type I, III and combined endoleaks were excluded from the present study cohort.

RESULTS

A combined adverse outcome event consisting of aneurysmal growth, transfemoral reintervention, and transabdominal secondary procedures (including laparoscopic branch vessel clipping) occurred in 55% in patients with type II endoleak at 3 years, compared to 15% in patients without any endoleak (p<0.0001). Conversion to open repair or post-EVAR rupture was not significantly associated with type II endoleaks. An independent association of device migration and expansion of the aneurysm with late conversion was observed. The cumulative incidence of aneurysm rupture at 3 years of follow-up was 1.2% for an annual rate of 0.4%. Variables that significantly and independently correlated with rupture were size of the aneurysm at preoperative measurement and device migration during follow-up.

CONCLUSION

Endoleak type II may not be harmless as it was more frequently associated with enlargement of the aneurysm and reinterventions. Large aneurysms and migration of the device were the main risk factors for rupture. The clinical implications of these findings may involve more frequent surveillance visits for patients with type II endoleak. Aneurysm expansion is a clear indication for reintervention. Patients with large aneurysms, 65 mm or larger, may also benefit from a more comprehensive surveillance schedule.

Type II endoleak after endovascular abdominal aortic aneurysm repair: a conservative approach with selective intervention is safe and cost-effective

OBJECTIVES

The conservative versus therapeutic approach to type II endoleak after endovascular repair of abdominal aortic aneurysm (EVAR) has been controversial. The purpose of this study was to evaluate the safety and cost-effectiveness of the conservative approach of embolizing type II endoleak only when persistent for more than 6 months and associated with aneurysm sac growth of 5 mm or more.

METHODS

Data for 486 consecutive patients who underwent EVAR were analyzed for incidence and outcome of type II endoleaks. Spiral computed tomography (CT) scans were reviewed, and patient outcome was evaluated at either office visit or telephone contact. Patients with new or late-appearing type II endoleak were evaluated with spiral CT at 6-month intervals to evaluate both persistence of the endoleak and size of the aneurysm sac. Persistent (>or=6 months) type II endoleak and aneurysm sac growth of 5 mm or greater were treated with either translumbar glue or coil embolization of the lumbar source, or transarterial coil embolization of the inferior mesenteric artery.

RESULTS

Type II endoleaks were detected in 90 (18.5%) patients. With a mean follow-up of 21.7 +/- 16 months, only 35 (7.2%) patients had type II endoleak that persisted for 6 months or longer. Aneurysm sac enlargement was noted in 5 patients, representing 1% of the total series. All 5 patients underwent successful translumbar sac embolization (n = 4) or transarterial inferior mesenteric artery embolization (n = 4) at a mean follow-up of 18.2 +/- 8.0 months, with no recurrence or aneurysm sac growth. No patient with treated or untreated type II endoleak has had rupture of the aneurysm. The mean global cost for treatment of persistent type II endoleak associated with aneurysm sac growth was US dollars 6695.50 (hospital cost plus physician reimbursement). Treatment in the 30 patients with persistent type II endoleak but no aneurysm sac growth would have represented an additional cost of US dollars 200000 or more. The presence or absence of a type II endoleak did not affect survival (78% vs 73%) at 48 months.

CONCLUSIONS

Selective intervention to treat type II endoleak that persists for 6 months and is associated with aneurysm enlargement seems to be both safe and cost-effective. Longer follow-up will determine whether this conservative approach to management of type II endoleak is the standard of care.

A UK Multi-centre Experience with a Second-generation Endovascular Stent-graft: Results from the Zenith Users Group

BACKGROUND

Endovascular aneurysm repair has been criticised for high rates of technical failure and secondary intervention. Second generation stent-grafts have been developed in an attempt to reduce these problems. The results of a UK multi-centre experience with a second generation device (Zenith) are presented.

METHODS

Data were collected retrospectively from five experienced UK vascular centres in patients undergoing endovascular aneurysm repair with the Zenith stent-graft.

RESULTS

A total of 269 patients underwent attempted aneurysm repair with the Zenith device. Median aneurysm diameter was 65 (interquartile range 52-78) mm. There were no conversions to open repair. Peri-operative mortality was 4.1% (11/269). On the initial post-operative scan, 94.1% of aneurysms were successfully excluded. During a median follow-up of 363 (interquartile range 154-720) days there were 19 secondary interventions and two aneurysm ruptures.

CONCLUSIONS

Second generation endovascular stent-graft designs such as the Zenith are associated with low rates of intra-operative technical complications. Few secondary interventions have been necessary during follow-up; however, surveillance is essential to ensure they continue to perform.

Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysms

Endovascular repair of abdominal aortic aneurysms shows promising initial results. Endoleaks represent one of the unique causes of endovascular repair failure not seen with traditional abdominal aortic aneurysm repair. Endoleaks occur when there is blood flow outside the stent-graft lumen but within the aneurysm sac. They can be difficult to diagnose and treat, and their management is a source of continued controversy. This review further defines endoleaks and the clinical challenges that they create. Current methods for endoleak detection, classification, and management are reviewed.

The significance and management of different types of endoleaks

Development of endovascular abdominal aortic aneurysm repair (EVAR) has been accompanied by previously unencountered complications. The most challenging but least understood of these complications is the incomplete seal of the endovascular graft (endoleak), a phenomenon that has a variety of causes. An important consequence of endoleakage may be persistent pressurization of the aneurysm sac, which may ultimately lead to post-EVAR rupture. Data of 110 European centers were recorded in a central database (EUROSTAR). Patient, anatomic characteristics, and operative and device details were correlated with the occurrence of different types of endoleaks. Outcome events during follow-up, particularly expansion of the aneurysm, incidence of conversion to open repair, and post-EVAR rupture were assessed in the different categories of endoleaks and in a group of patients without any endoleak. Type I and III endoleak were associated with an increased frequency of open conversions or risk of rupture of the aneurysm. Device-related endoleaks also correlated with an increased need for secondary interventions. These types of endoleaks need to be treated without delay, and when no other possibilities are present, an open conversion to avert the risk of rupture should be considered. Type II endoleaks do not pose an indication for urgent treatment. However, they may not be harmless, because there was a frequent association with enlargement of aneurysm and reinterventions. Our findings suggest that more frequent surveillance examinations are indicated than in patients without collateral endoleak. The indication for intervention is primarily dictated by documented expansion of the aneurysm.

Controversies in the management of type II "branch" endoleaks following endovascular abdominal aortic aneurysm repair

Successful endovascular aortic aneurysm repair (EVAR) is often defined as complete exclusion of blood flow within the aneurysm sac. Perigraft flow, also known as endoleak, is the most common complication following EVAR. Attachment site related endoleaks (type I) are generally considered to warrant some form of intervention due to the belief that they represent a risk for future rupture. Management of type II endoleaks, also known as branch or collateral endoleaks, is more controversial. Some advocate a policy of watchful-waiting whereas others treat all type II endoleaks as soon as they are discovered. The following review explores the controversies pertaining to the management, diagnosis and surveillance imaging, and treatment of type II endoleaks.