Effect of antiplatelet therapy on aneurysmal sac expansion associated with type II endoleaks after endovascular aneurysm repair

Practice patterns of antiplatelet and anticoagulant therapy after fenestrated/branched endovascular aortic repair

OBJECTIVE

Antiplatelet and/or anticoagulant therapy are commonly prescribed after fenestrated/branched endovascular aortic repair (F/BEVAR). However, the optimal regimen remains unknown. We sought to characterize practice patterns and outcomes of antiplatelet and anticoagulant use in patients who underwent F/BEVAR.

METHODS

Consecutive patients enrolled (2012-2023) as part of the United States Aortic Research Consortium (US-ARC) from 10 independent physician-sponsored investigational device exemption studies were evaluated. The cohort was characterized by medication regimen on discharge from index F/BEVAR: (1) Aspirin alone OR P2Y12 alone (single-antiplatelet therapy [SAPT]); (2) Anticoagulant alone; (3) Aspirin + P2Y12 (dual-antiplatelet therapy [DAPT]); (4) Aspirin + anticoagulant OR P2Y12 + anticoagulant (SAPT + anticoagulant); (5) Aspirin + P2Y12 + anticoagulant (triple therapy [TT]); and (6) No therapy. Kaplan-Meier analysis and Cox proportional hazards modeling were used to compare 1-year outcomes including survival, target artery patency, freedom from bleeding complication, freedom from all reinterventions, and freedom from stent-specific reintervention.

RESULTS

Of the 1525 patients with complete exposure and outcome data, 49.6% were discharged on DAPT, 28.8% on SAPT, 13.6% on SAPT + anticoagulant, 3.2% on TT, 2.6% on anticoagulant alone, and 2.2% on no therapy. Discharge medication regimen was not associated with differences in 1-year survival, bleeding complications, composite reintervention rate, or stent-specific reintervention rate. However, there was a significant difference in 1-year target artery patency. On multivariable analysis comparing with SAPT, DAPT conferred a lower hazard of loss of target artery patency (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.27-0.84; P = .01). On sub-analyses of renal stents alone or visceral stents alone, DAPT no longer had a significantly lower hazard of loss of target artery patency (renal: HR, 0.66; 95% CI, 0.35-1.27; P = .22; visceral: HR, 0.31; 95% CI, 0.05-1.9; P = .21). Lastly, duration of DAPT therapy (1 month, 6 months, or 1 year) did not significantly affect target artery patency.

CONCLUSIONS

Practice patterns for antiplatelet and anticoagulant regimens after F/BEVAR vary widely across the US-ARC. There were no differences in bleeding complications, survival or reintervention rates among different regimens, but higher branch vessel patency was noted in the DAPT cohort. These data suggest there is a benefit in DAPT therapy. However, the generalizability of this finding is limited by the retrospective nature of this data, and the clinical significance of this finding is unclear, as there is no difference in survival, bleeding, or reintervention rates amongst the different regimens. Hence, an "optimal" regimen, including the duration of such regimen, could not be clearly discerned. This suggests equipoise for a randomized trial, nested within this cohort, to identify the most effective antiplatelet/anticoagulant regimen for the growing number of patients being treated globally with F/BEVAR.

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.

Factors Influencing on the Aneurysm Sac Shrinkage after Endovascular Abdominal Aortic Aneurysm Repair by the Analysis of the Patients with the Aneurysm Sac Shrinkage and Expansion

Objectives: The aneurysmal sac shrinkage has been reported as the strong predictor of favorable long-term outcome after endovascular aneurysm repair (EVAR). We evaluated the effects of perioperative and intraoperative factors on the aneurysm sac shrinkage. Methods: EVAR was performed for 296 patients during August 2009-December 2021. Nine patients with type Ia, Ib, or III; 69 patients with the sac diameter change less than 5 mm; and five patients with sac re-expansion after shrunk more than 5 mm were excluded. Thus, patients with sac shrinkage 5 mm or more (79 patients, shrinkage group) and with sac expansion 5 mm or more (18 patients) were included in this study. Antifibrinolytic therapy with tranexamic acid (TXA) 1500 mg/day for 6 months after EVAR was introduced in March 2013 and patent aortic side branches were coil embolized during EVAR since July 2015. Patients' background and patent aortic side branches at the end of EVAR were evaluated. Results: Univariate analysis for comparison between patients with sac shrinkage and sac expansion revealed that males (82.3% vs. 55.6%, p = 0.021), without antiplatelet therapy (40.5% vs. 66.7%, p = 0.044) and TXA (79.8% vs. 38.9%, p <0.001), were significantly associated with sac shrinkage. By multivariate analysis, the odds ratio of sac shrinkage was 11.7 for males, 0.1 for the patients on antiplatelet therapy, and 6.5 for the patient who received TXA. The patients with patent inferior mesenteric artery (IMA) were less in the shrinkage group (20.3% vs. 77.8%, p <0.001) and with two or less patent lumbar arteries (LAs) were more in the shrinkage group (82.3% vs. 33.3%, p < 0.001). The odd ratio of sac shrinkage was 7.8 for occluded IMA and 3.9 for two or less patent LAs. Conclusion: The possibility of sac shrinkage would be high for the patient with occluded IMA and two or less patent LA at the end of EVAR, and that patient received TXA after EVAR. (This is a translation of Jpn J Vasc Surg 2022; 31: 291-297.).

Thrombosis in the pathogenesis of abdominal aortic aneurysm

Background

Abdominal aortic aneurysms (AAAs) are a relatively common vascular pathology of the elderly with high morbidity potential. Irreversible degeneration of the aortic wall leads to lethal rupture if left untreated. Nearly all AAAs contain intraluminal thrombus (ILT) to a varying degree, yet the mechanisms explaining how thrombosis is disturbed in AAA are relatively unknown. This review examined the thrombotic complications associated with AAA, the impact of thrombosis on AAA surgical outcomes and AAA pathogenesis, and the use of antithrombotic therapy in the management of this disease.

Methods

A literature search of the PubMed database was conducted using relevant keywords related to thrombosis and AAAs.

Results

Thrombotic complications are relatively infrequent in AAA yet carry significant morbidity risks. The ILT can impact endovascular aneurysm repair by limiting anatomic suitability and influence the risk of endoleaks. Many of the pathologic mechanisms involved in AAA development, including hemodynamics, inflammation, oxidative stress, and aortic wall remodeling, contain pathways that interact with thrombosis. Conversely, the ILT can also be a source of biochemical stress and exacerbate these aneurysmal processes. In animal AAA models, antithrombotic therapies have shown favorable results in preventing and stabilizing AAA. Antiplatelet agents may be beneficial for reducing risks of major adverse cardiovascular events in AAA patients; however, neither antiplatelet nor anticoagulation is currently used solely for the management of AAA.

Conclusions

Thrombosis and ILT may have detrimental effects on AAA growth, rupture risk, and patient outcomes, yet there is limited understanding of the pathologic thrombotic mechanisms in aneurysmal disease at the molecular level. Preventing ILT using platelet and coagulation inhibitors may be a reasonable theoretical target for aneurysm progression and stability; however, the practical benefits of current antithrombotic therapies in AAA are unclear. Further research is needed to demonstrate the extent to which thrombosis impacts AAA pathogenesis and to develop novel pharmacologic strategies for the medical management of this disease.

Research advances in drug therapy for abdominal aortic aneurysms over the past five years: An updated narrative review

BACKGROUND

Abdominal aortic aneurysms (AAA) rupture can lead to patient death. Surgical treatment is currently the optimal treatment for AAA with large diameter (≥50 mm). For AAA with small diameter (30-50 mm), how to administer effective pharmacological treatment to reduce aneurysm expansion rate and rupture risk is the current focus in the field of vascular surgery. There is still no effective drug for the treatment of asymptomatic AAA.

METHODS

This article searches the PubMed, Web of Science, Embase, and Cochrane databases for clinical studies on the drug treatment of abdominal aortic aneurysms in the past 5 years. The latest progress in the drug treatment of AAA was reviewed, including antibiotics, antihypertensive drugs, antiplatelet drugs, hypoglycemic drugs, hypolipidemic drugs, mast cell inhibitors and corticosteroids.

RESULTS

25 studies were included in this narrative review. Among them, metformin revealed therapeutic effect in 2 prospective cohort study and 3 retrospective cohort study. The therapeutic effect of statins was controversial in 3 retrospective cohort study. However, the definite therapeutic effects of antihypertensive agents, antibiotics, mast cell inhibitors, antiplatelet agents and corticosteroids on abdominal aortic aneurysms have not been verified in prospective studies.

CONCLUSION

Metformin provided a positive effect in reducing expansion rate, rupture risk, and perioperative mortality. The therapeutic effect of statins was controversial, which warrant further validation in prospective cohorts. However, there is still a lack of effective agents for the treatment of AAA based on recent studies.

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.

Platelet function changes in patients undergoing endovascular aortic aneurysm repair: Review of the literature

Patients with abdominal aortic aneurysm (AAA) have a higher risk of cardiovascular (CV) events, which seems to be associated with disturbed platelet (PLT) function. Endovascular aneurysm repair (EVAR) is an emerging, less-invasive treatment alternative to surgical AAA repair. Both platelet function abnormalities in patients with AAA and the effect of EVAR on platelet function are poorly understood. In this review, we aim to fill the gap regarding the effect of EVAR on PLT function in AAA patients by discussing PLT function disturbances in patients with AAA, PLT function changes after EVAR, evidence from clinical studies regarding PLT function before and after EVAR, and antiplatelet or and antithrombotic treatment in patients undergoing EVAR. The goal of our review is to summarize the contemporary knowledge and initiate further studies to better understand PLT function changes in patients undergoing EVAR, optimize the pharmacotherapy before and after EVAR and further improve outcomes in this group of patients.

Platelet olfactory receptor activation limits platelet reactivity and growth of aortic aneurysms

As blood transitions from steady laminar flow (S-flow) in healthy arteries to disturbed flow (D-flow) in aneurysmal arteries, platelets are subjected to external forces. Biomechanical platelet activation is incompletely understood and is a potential mechanism behind antiplatelet medication resistance. Although it has been demonstrated that antiplatelet drugs suppress the growth of abdominal aortic aneurysms (AAA) in patients, we found that a certain degree of platelet reactivity persisted in spite of aspirin therapy, urging us to consider additional antiplatelet therapeutic targets. Transcriptomic profiling of platelets from patients with AAA revealed upregulation of a signal transduction pathway common to olfactory receptors, and this was explored as a mediator of AAA progression. Healthy platelets subjected to D-flow ex vivo, platelets from patients with AAA, and platelets in murine models of AAA demonstrated increased membrane olfactory receptor 2L13 (OR2L13) expression. A drug screen identified a molecule activating platelet OR2L13, which limited both biochemical and biomechanical platelet activation as well as AAA growth. This observation was further supported by selective deletion of the OR2L13 ortholog in a murine model of AAA that accelerated aortic aneurysm growth and rupture. These studies revealed that olfactory receptors regulate platelet activation in AAA and aneurysmal progression through platelet-derived mediators of aortic remodeling.

Factors Associated With Spontaneous Sac Shrinkage in Patients With Persistent Type 2 Endoleaks After EVAR

PURPOSE

Despite controversy surrounding the management of type 2 endoleaks (T2ELs) after endovascular aortic aneurysm repair (EVAR), the current European guidelines recommend reintervention for T2ELs when the aneurysm expands by ≥10 mm. Meanwhile, sac shrinkage ≥10 mm can be considered low risk for failure even with T2ELs, and the guidelines suggest less frequent follow-up delayed until 5 years after EVAR. This study reviewed patients with persistent T2ELs to identify predictors of spontaneous sac shrinkage (SpS) within 5 years.

METHODS

A retrospective review of elective EVAR for infrarenal aortic aneurysms between June 2007 and December 2017. Patients with >1 year follow-up and persistent T2ELs, defined as T2ELs confirmed at both the 6 and 12 month follow-up with contrast-enhanced computed tomography (CT), were included. Any reintervention or type 1 or 3 endoleaks within 12 months were excluded. SpS was defined as a ≥10 mm reduction in diameter without any reintervention. Aneurysm enlargement (AnE) was defined as a ≥5 mm increase in diameter. Factors associated with SpS within 5 years were analyzed. The clinical outcomes were reviewed.

RESULTS

Among 726 patients, 162 patients had persistent isolated T2ELs. After excluding 21 patients, 141 patients were enrolled. During a median follow-up of 43 months (interquartile range [IQR], 26-60), 28 SpS and 39 AnE were observed, and 31 reinterventions were performed. The cumulative rates of SpS were 14.2%±2.9% and 25.6%±5.1% at 1 and 5 years. Cox regression analysis revealed that the presence of ≥6 patent lumbar arteries had a significant negative correlation with SpS (p=0.036). During further follow-up after SpS, 2 reinterventions for type 1a and 3b endoleaks were required at 49 and 45 months.

CONCLUSIONS

Patients with fewer patent lumbar arteries were likely to experience SpS within 5 years, even in the presence of persistent T2ELs. Follow-up imaging studies were advisable earlier than 5 years, even after SpS.

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.

Platelet Count Recovery after Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

Objective: To find a new predictor of endoleak (EL) and aneurysm sac expansion after endovascular aneurysm repair (EVAR), we evaluated the platelet count recovery (PCR) process after EVAR.

Materials and Methods: Two hundred five patients treated with elective EVAR from 2007 to 2015 were retrospectively analyzed. We compared the platelet count ratio until postoperative day (POD) 7 to the presurgical baseline between patients with and without persistent EL (≥ 6 months). Subsequently, we calculated the optimal platelet count ratio for distinguishing persistent EL using receiver-operating characteristics analysis. A platelet count ratio on POD7 ≥118% was defined as the PCR. We evaluated the PCR’s influence on the cumulative aneurysm sac expansion rate.

Results: The average platelet count ratio on POD7 rose above baseline (112%), and the ratio was attenuated by persistent EL (103%). Of 205 patients, 126 (61%) were assigned to the disturbed PCR group (PCR(−) group). Cumulative aneurysm sac expansion rate was higher in the PCR(−) group than the PCR(+) group (34.4% vs. 12.8% in 5 years, p=0.01).

Conclusion: Disturbed PCR after EVAR may be associated with ELs and eventual aneurysm sac expansion.

Platelets reflect the fate of type II endoleak after endovascular aneurysm repair

OBJECTIVE

The management of type II endoleak (T2E) remains controversial because of the heterogeneous outcome. For blood-based screening to detect malignant T2E, we focused on platelets after endovascular aneurysm repair (EVAR) and compared them with the prognosis of T2Es.

METHODS

From 2007 to 2015, there were 249 patients treated with EVAR for abdominal aortic aneurysm who were evaluated retrospectively. The mean follow-up period was 3.5 ± 0.2 years. T2Es that had aneurysm sac enlargement or converted to type I or type III endoleak were defined as malignant; the other T2Es were considered benign. Cases without any complications, including T2E, were defined as completed. We compared the platelet count on postoperative days (PODs) 1 to 7 with preoperative baseline values among the three groups. Sequentially, we calculated the cutoff of the platelet ratio on POD 7 to the baseline value in relation to malignant T2E using receiver operating characteristic analysis, and the cutoff ratio was 113% (sensitivity, 79%; specificity, 58%). We then reclassified T2E patients into T2E-high platelet (T2E-HP; ≥113%) or T2E-low platelet (T2E-LP; <113%) groups. The influence of platelets on T2E was evaluated with reintervention rate and cumulative aneurysm sac enlargement rate using the Kaplan-Meier method.

RESULTS

T2Es were found in 70 patients (28%), and 179 patients were assigned to the completed group. Malignant and benign T2Es were found in 33 and 37 patients, respectively. No difference was found in the preoperative baseline values. On POD 7, the platelet count in the malignant T2E group was significantly lower than that in the completed and benign T2E groups (168 × 10³/μL vs 207 × 10³/μL and 201 × 10³/μL; P = .0124). Then, 27 and 43 patients were assigned to the T2E-HP and T2E-LP groups, respectively. The reintervention-free survival rate in the T2E-LP group was lower than that in the completed group (at 3 years, 66.4% ± 8.0% vs 71.9% ± 4.0%; P = .0031). Among T2E patients, the cumulative aneurysm sac enlargement rates in the T2E-LP group were significantly higher than those in the T2E-HP group (at 3 years, 34.6% ± 8.2% vs 20.6% ± 8.2%; P = .0105). Univariate Cox proportional hazards analysis for the cumulative aneurysm sac enlargement rates among T2E patients showed that sex, dual antiplatelet therapy, and lower platelet ratio (<113%) were significant predictors; multivariate analysis showed that T2E-LP was the only significant predictor (hazard ratio, 2.60; P = .0355).

CONCLUSIONS

The platelet count of patients with malignant T2Es on POD 7 was definitively lower than that of patients with completed EVAR or with benign T2Es. The lower platelet count on POD 7 could be a risk factor for aneurysm sac enlargement among patients with T2Es.

Results of Transarterial Embolization for Treating Type 2 Endoleaks: A Single-Center Experience

BACKGROUND

Type 2 endoleaks (T2Es) are the main cause of reintervention after endovascular repair of abdominal aortic aneurysms (EVAR). The objective of this study is to quantify success rates of T2E treatment.

METHODS

This study involves a retrospective analysis of a prospectively maintained database containing data on all consecutive patients treated for a T2E between 2003 and 2017 in a single center. Technical success was defined as absence of endoleak in the final angiographic control after treatment. Clinical success was defined as absence of sac growth over 5 mm in the contrast-enhanced computed tomography performed a year thereafter. Statistics included Kaplan-Meier survival estimates.

RESULTS

A total of 528 elective EVARs were performed in the period. Thirty-six of these (6.8%) developed a T2E requiring reintervention, a median of 37.9 months after EVAR. Twenty-five percent of the treatments were performed more than 5 years after intervention. Twenty-eight of the 36 treatments were performed via transarterial embolization. For this technique, technical success was 71.4% and clinical success was 62.5%. A subsequent reintervention was required in 35.7% of patients. In this cohort, the rate of aneurysm rupture was 10.7% (n = 3/28), open surgical conversion was needed in 2 of 28 cases (7.1%), and rate of aneurysm-related death was 14.3% (n = 4/28) over follow-up.

CONCLUSIONS

A high percentage of patients are at risk of adverse outcomes after T2E treatment. Strict imaging follow-up is still needed in this population.

Post-EVAR aneurysm sac shrinkage is prognostically favorable, but does not justify withholding follow-up

BACKGROUND

One of the main drawbacks of endovascular aortic aneurysm repair (EVAR) compared to open aortic surgery is the possibility of developing endoleaks and secondary aneurysm rupture, requiring frequent imaging follow-up. This study aims to identify prognostic factors that could be incorporated in follow-up protocols, which might lead to better personalized, lower cost and safe EVAR follow-up.

METHODS

A retrospective study was performed including all patients who underwent elective EVAR from January 2000 to December 2015. Follow-up data were gathered by reviewing medical files for radiographic imaging. Linear and logistic regressions were used to assess predictive factors for aneurysm shrinkage.

RESULTS

In 361 patients, aneurysm sac shrinkage of 10 mm or more was measured in 152 (42.1%) patients. Patients with ≥10-mm aneurysm shrinkage had fewer endoleaks (4.3% vs. 24.6%, P<0.0001) and fewer re-interventions for endoleak (3.0% vs. 10.1%, P=0.007). Aneurysm sac shrinkage was correlated with the absence of endoleak development (OR 0.36, 95% CI 0.19-0.66, P=0.001). In patients who had achieved ≥10-mm shrinkage of the aneurysm sac, no further significant growth was seen, compared to 38 (15.3%) patients who did not attain size reduction (P<0.001).

CONCLUSIONS

Once patients achieve ≥10-mm aneurysm sac shrinkage, they are less prone to developing subsequent aneurysm growth and have significantly lower risk of requiring surgery for endoleaks. However, a small number of patients remain at risk of requiring endoleak surgery after aneurysm shrinkage. Therefore, we would not recommend ceasing life-long imaging follow-up after significant aneurysm sac shrinkage, though it might be safe to increase the interval of follow-up.

Perioperative factors associated with aneurysm sac size changes after endovascular aneurysm repair

PURPOSE

To identify the perioperative factors associated with aneurysm size changes after endovascular aortic aneurysm repair (EVAR).

METHODS

Between August, 2008 and December, 2014, 187 patients underwent EVAR treatment in our institution. The subjects of this study were 135 of these patients without peripheral artery disease, who were followed up with computed tomography (CT) for 3 years. Significant aneurysm size change was defined as sac size change of more than 5 mm from the baseline.

RESULTS

Sac enlargement was identified in 25 patients (18.5%) and sac shrinkage was identified in 59 (43.7%) patients. The factors associated with sac enlargement were postoperative pulse wave velocity (OR: odds ratio 3.80, p = 0.047), prevalence of a type 2 endoleak 1 week after surgery (OR 4.26, p = 0.022), inner diameter (OR 1.10, p = 0.005), and distance from the lower renal artery to the terminal aorta (OR 1.05, p = 0.017). The factors associated with sac shrinkage were prevalence of a type 2 endoleak (OR 0.09, p < 0.001) and preoperative pulse wave velocity (OR 0.32, p = 0.022). The factors independently associated with type 2 endoleak were the use of an Excluder device (OR 3.99, p = 0.002) and the length of the aneurysm (OR 1.02, p = 0.027).

CONCLUSION

Inner diameter, treatment length, perioperative pulse wave velocity, and type 2 endoleak were associated with sac size changes after EVAR.