The mechanism and therapy of aortic aneurysms.

Aortic aneurysm is a chronic aortic disease affected by many factors. Although it is generally asymptomatic, it poses a significant threat to human life due to a high risk of rupture. Because of its strong concealment, it is difficult to diagnose the disease in the early stage. At present, there are no effective drugs for the treatment of aneurysms. Surgical intervention and endovascular treatment are the only therapies. Although current studies have discovered that inflammatory responses as well as the production and activation of various proteases promote aortic aneurysm, the specific mechanisms remain unclear. Researchers are further exploring the pathogenesis of aneurysms to find new targets for diagnosis and treatment. To better understand aortic aneurysm, this review elaborates on the discovery history of aortic aneurysm, main classification and clinical manifestations, related molecular mechanisms, clinical cohort studies and animal models, with the ultimate goal of providing insights into the treatment of this devastating disease. The underlying problem with aneurysm disease is weakening of the aortic wall, leading to progressive dilation. If not treated in time, the aortic aneurysm eventually ruptures. An aortic aneurysm is a local enlargement of an artery caused by a weakening of the aortic wall. The disease is usually asymptomatic but leads to high mortality due to the risk of artery rupture.

Hospital incidence and mortality of patients treated for abdominal aortic aneurysms in Switzerland - a secondary analysis of Swiss DRG statistics data.

AIM OF THE STUDY: To analyse hospital incidence and in-hospital mortality of patients treated for abdominal aortic aneurysms in Switzerland. METHODS: Secondary data analysis of case-related hospital discharge data of the Swiss Federal Statistical Office for the years 2009-2018. Patients who were hospitalised and surgically treated for nonruptured abdominal aortic aneurysms or hospitalised and treated for ruptured abdominal aortic aneurysms were included in the analysis. Standardised annual incidences rates were calculated using the European standard population 2013. In-hospital all-cause mortality rates were calculated as raw values and standardised for age, sex, and the van Walraven comorbidity score. RESULTS: A total of 10,728 cases were included in this study, of which 87.1% were male. Overall, 22.7% of the patients presented with a ruptured abdominal aortic aneurysm; 46% of these cases were surgically treated whereas 54% received conservative therapy. The age-standardised cumulative hospital incidences for treatment of nonruptured abdominal aortic aneurysms were 2.6 (95% confidence interval 2.5-2.8) and 19.7 (19.2-20.1) per 100,000 for women and men, respectively; for ruptured aneurysms it was 0.4 (0.3-2.4) per 100,000 in women, and 2.7 (2.6-2.9) in men. The annual incidence rates were stable in the decade observed. The adjusted mortality rates for treatment of nonruptured aneurysms decreased from 5.5% (2.6-11.2%) in 2009 to 1.4% (0.5-3.6%) in 2018 in women, and from 2.4% (1.3-4.5%) in 2009 to 0.6% (0.2-1.5%) in 2018 in men. The adjusted mortality rates for treatment of ruptured abdominal aortic aneurysms remained high without relevant improvements for either sex over time: for women 32.4% (24.1-42.1%), for men 19.7% (16.8-22.8%). CONCLUSIONS: The hospital incidence rates for nonruptured and ruptured abdominal aortic aneurysms remained unchanged in the decade observed. Compared with Germany, there was no evidence for a decrease in the annual incidence rates for ruptured abdominal aortic aneurysms in Switzerland. Mortality rates in the elective setting were low and decreased in the last decade but remained high in patients treated for ruptured aneurysms. Efforts to reduce the incidence of ruptured abdominal aortic aneurysms are needed to reduce aneurysm-related mortality in Switzerland.

Induction of CD73 prevents death after emergency open aortic surgery for a ruptured abdominal aortic aneurysm: a randomized, double-blind, placebo-controlled study.

Mortality remains high after emergency open surgery for a ruptured abdominal aortic aneurysm (RAAA). The aim of the present study was to assess, if intravenous (IV) Interferon (IFN) beta-1a improve survival after surgery by up-regulating Cluster of differentiation (CD73). This is a multi-center phase II double-blind, 2:1 randomized, parallel group comparison of the efficacy and safety of IV IFN beta-1a vs. placebo for the prevention of death after open surgery for an infra-renal RAAA. All study patients presented a confirmed infra-renal RAAA, survived the primary emergency surgery and were treated with IFN beta-1a (10 µg) or matching placebo for 6 days after surgery. Major exclusion criteria included fatal hemorrhagic shock, chronic renal replacement therapy, diagnosed liver cirrhosis, severe congestive heart failure, advanced malignant disease, primary attempt of endovascular aortic repair (EVAR), and per-operative suprarenal clamping over 30 min. Main outcome measure was all-cause mortality at day 30 (D30) from initial emergency aortic reconstruction. The study was pre-maturely stopped due to a reported drug-drug interaction and was left under-powered. Out of 40 randomized patients 38 were included in the outcome analyses (27 IFN beta-1a and 11 placebo). There was no statistically significant difference between treatment groups at baseline except more open-abdomen and intestinal ischemia was present in the IFN beta-1a arm. D30 all-cause mortality was 22.2% (6/27) in the IFN beta-1a arm and 18.2% (2/11) in the placebo arm (OR 1.30; 95% CI 0.21-8.19). The most common adverse event relating to the IFN beta-1a was pyrexia (20.7% in the IFN beta-1a arm vs. 9.1% in the placebo arm). Patients with high level of serum CD73 associated with survival (P = 0.001) whereas the use of glucocorticoids and the presence of IFN beta-1a neutralizing antibodies associated with a poor CD73 response and survival. The initial aim of the trial, if postoperative INF beta-1a treatment results on better RAAA survival, could not be demonstrated. Nonetheless the anticipated target mechanism up-regulation of CD73 was associated with 100% survival. According to present results the INF beta-1a induced up-regulation of serum CD73 was blocked with both use of glucocorticoids and serum IFN beta-1a neutralizing antibodies. The study was pre-maturely stopped due to interim analysis after a study concerning the use if IV IFN beta-1a in ARDS suggested that the concomitant use of glucocorticoids and IFN beta-1a block the CD73 induction. Trial registration: ClinicalTrials.gov NCT03119701. Registered 19/04/2017 (retrospectively registered).

Culture-Negative Mycotic Aortic Aneurysms Probably Have a Less Severe Clinical Nature Than Culture-Positive Counterparts.

BACKGROUND: Mycotic aortic aneurysm constitutes a potentially devastating disease that necessitates prompt suspicion and diagnosis. There is no exact consensus for treatment, but removal of infected tissues and prolonged use of antimicrobials based on the identified causative microorganisms seem widely acceptable and have been similarly practiced worldwide. However, some patients still show no identified microorganisms. In this study, we sought to determine whether there are any clinical significance or differences of note in culture-negative mycotic aortic aneurysms. METHODS: Between October 2003 and August 2018, 71 patients were identified as treated for mycotic aortic aneurysms at a single tertiary institution. Review of medical records and imaging studies were completed to collect the following information: demographics, previous medical/surgical history regarding potential infection sources, laboratory and radiologic findings, clinical presentations, treatment method, and morbidity and mortality rates. For analysis, patients were categorized into two groups: the blood and/or tissue culture-positive (CP) group and the blood and/or tissue culture-negative (CN) group. The latter was further divided as CN with identified microorganism by molecular biologic methods [CN(+)] and CN with no identified microorganism [CN(-)]. RESULTS: More patients in the CP group were symptomatic than were in the CN(+) group (100% vs. 80%; P = 0.034). However, identification of causative microorganisms did not result in a difference in symptom status upon comparing the [CP + CN(+)] and [CN(-)] groups. Inflammatory markers were the most elevated in the CP group and least elevated in the CN(-) group. The aneurysm growth rate seemed slower in the CN(-) group than in the CN(+) and CP groups (1.3 vs. 3.4 vs. 9 mm/month respectively). Aneurysm rupture at initial presentation was more prevalent in the CP group (33.3%). 18F-Fluorodeoxyglucose-positron emission tomography showed increased uptake regardless of whether or not the microorganisms were identified. Early mortality and disease-specific mortality rates during the follow-up period were higher in the CP group but without statistical significance. CONCLUSIONS: Compared with the CP group, the CN groups appeared clinically less severe, and also exhibited a relatively less devastating course as exhibited by the slower aneurysm expansion rate and smaller number of ruptured aneurysms at the initial presentation.

Late outcomes after endovascular and open repair of large abdominal aortic aneurysms.

OBJECTIVE: The risk of aortic abdominal aneurysm (AAA) rupture increases with an increasing aneurysm diameter. However, the effect of the AAA diameter on late outcomes after aneurysm repair is unclear. Therefore, we assessed the association of a large AAA diameter with late outcomes for patients undergoing open and endovascular AAA repair. METHODS: We identified all patients who had undergone elective open or endovascular infrarenal aneurysm repair from 2003 to 2016 in the Vascular Quality Initiative linked to Medicare claims for long-term outcomes. A large AAA diameter was defined as a diameter >65 mm. We assessed the 5-year reintervention, rupture, mortality, and follow-up rates. We constructed propensity scores and used inverse probability-weighted Kaplan-Meier estimations and Cox proportional hazard models to identify independent associations between large AAA repair and our outcomes. RESULTS: Of the 21,119 aneurysm repairs identified, 15.2% were for large AAAs. Of the 21,119 repairs, 19,017 were endovascular and 2102 were open. The large AAA cohort was less likely to have undergone endovascular aneurysm repair (EVAR; 84.9% vs 91%; P < .001), more likely to be older (median age, 76 vs 75 years; P < .001), and were less likely to be women (16.2% vs 21.7%; P < .001). After EVAR, patients with large AAAs had had lower adjusted 5-year freedom from reintervention (73.9% vs 84.6%; P < .001), freedom from rupture (88.5% vs 93.6%; P < .001), survival (58.0% vs 66.4%; P < .001), and freedom from loss to follow-up (77.7% vs 83.3%; P < .001) compared with patients with smaller AAAs. However, after open repair, the adjusted 5-year freedom from reintervention (95.8% vs 93.3%; P = .11), freedom from rupture (97.4% vs 97.8%; P = .32), survival (70.4% vs 74.0%; P = .13), and loss to follow-up (60.5% vs 62.8%; P = .86) were similar to the results for patients with smaller AAAs. For patients with large AAAs, the adjusted 5-year survival was lower after EVAR than that after open repair (55.3% vs 63.7%) but not after smaller AAA repair (67.3% vs 70.6%). CONCLUSIONS: The 5-year adjusted reintervention, ruptures, mortality, and loss to follow-up rates for patients who had undergone large AAA EVAR were higher than those for patients who had undergone small AAA EVAR and large AAA open repair. Therefore, for patients with large AAAs who are medically fit, open repair should be strongly considered. Furthermore, these findings highlight the necessity for rigorous long-term follow-up after EVAR.

Midterm single-center results after endovascular aneurysm sealing reveal a high rate of stent graft migration, secondary aneurysm ruptures, and device-related reinterventions.

OBJECTIVE: To report procedural results and mid-term follow-up outcomes of patients treated with endovascular aneurysm sealing (EVAS) for abdominal aortic disease. METHODS: In this retrospective observational study, all patients treated with EVAS between March 2013 and January 2018 for abdominal aortic aneurysm (AAA) or abdominal penetrating aortic ulcer were included. The datasets included demographics, aneurysm morphology, and procedural and clinical surveillance outcomes. Furthermore, patients treated within the original instructions for use (IFU-group) were compared with patients treated outside the IFU (non-IFU-group) with regard to survival, reintervention-free survival, freedom from type I endoleak, and freedom from stent graft migration. RESULTS: Seventy patients were included (67 male; median age, 72.5 years). Sixty-five patients were treated for AAA and 5 patients for abdominal penetrating aortic ulcer. Sixty-nine cases were treated electively (98.6%). Technical success was achieved in 68 cases (97.1%). The median clinical follow-up was 50.5 months (interquartile range, 29.3-62.7 months) with a median computed tomography angiographic follow-up of 38.5 months (interquartile range, 17.1-60.2 months). There were five deaths during the study period (7.1%), four of which were aneurysm related (5.7%). Five secondary AAA ruptures were detected (7.1%). Overall, 25 of 70 patients (35.7%) underwent 35 reinterventions, mostly owing to thrombotic complications (18.6%), stent graft migration (17.1%), and type I endoleak (12.9%). Fifteen patients were treated outside of the IFU (non-IFU-group) (21.4%). The estimated reintervention-free survival for the entire cohort at 30 days and 1, 3, and 5 years was 94.3%, 88.5%, 72%, and 56.9%, respectively. Freedom from stent graft migration at 1, 3, and 5 years was 98.6%, 82.0%, and 47.3%, respectively. The estimated freedom from type I endoleak at 30 days and 1, 3, and 5 years in the IFU-group was 100%, 100%, 94.9% and, 91.1% and significantly different when compared with the non-IFU-group with 79.5%, 72.2%, 72.2%, and 72.2% (P = .012). CONCLUSIONS: Although the technical and initial results were satisfying, the mid-term results were disappointing. The enforcement of a close follow-up protocol for all patients treated with EVAS, especially vigilant for stent graft migration to prevent secondary type I endoleak and rupture, is strongly recommended.

Venoarterial Extracorporeal Membrane Oxygenation for Ruptured Sinus of Valsalva Aneurysm.

Sinus of Valsalva aneurysm rupture is a potentially fatal condition that requires urgent surgical intervention. We report a case of right sinus of Valsalva aneurysm rupture into the right atrium in a patient with a monocuspid aortic valve successfully managed with femoral venoarterial extracorporeal membrane oxygenation after pulseless electrical activity cardiac arrest to facilitate complete surgical repair. The patient made a full recovery and was discharged home with no neurologic deficit and had no limitations at the 1-year follow-up. This case highlights the utility of venoarterial extracorporeal membrane oxygenation in facilitating successful surgical repair when patients present in extremis.

Surgical outcomes of acute type A aortic dissection in patients undergoing cardiopulmonary resuscitation.

OBJECTIVES: The surgical indications for acute type A aortic dissection (AAAD) in patients in cardiopulmonary arrest remain controversial. Outcomes of AAAD for patients who underwent cardiopulmonary resuscitation (CPR) were evaluated. METHODS: Between 2004 and 2018, of the 519 patients who underwent AAAD repair, 34 (6.6%) required CPR before or on starting AAAD repair. The patients were divided into 2 groups, survivors (n = 13) and nonsurvivors (n = 21), to compare the early operative outcomes, including mortality and neurological events. RESULTS: The major cause of cardiovascular collapse requiring CPR was aortic rupture/cardiac tamponade (n = 21 [61.8%]), followed by coronary malperfusion (n = 12 [35.3%]) and acute aortic valve regurgitation (n = 3 [8.8%]). There were 3 (23.1%) patients in the survivors group and 11 (52.4%) in the nonsurvivors group who required ongoing CPR at the beginning of AAAD repair (P = .039). Of these patients, 1 survivor and 6 nonsurvivors could not achieve return of spontaneous circulation after pericardiotomy (P = .045). Although the duration from onset or arrival to the operating room was similar (P = .35 and P = .49, respectively), overall duration of CPR was shorter in survivors (10 minutes [range, 7.5-16 minutes] vs 16.5 minutes [range, 15-20 minutes]; P = .044). All survivors without any neurological deficits showed return of spontaneous circulation after pericardiotomy. Multivariate regression modeling showed that CPR duration >15 minutes was a significant risk factor for in-hospital mortality (P = .0040). CONCLUSIONS: CPR duration beyond 15 minutes may be a contraindication for AAAD repair. Moreover, we should reconsider surgery for patients who cannot achieve return of spontaneous circulation after pericardiotomy.

Midterm outcomes for 605 patients receiving Endologix AFX or AFX2 Endovascular AAA Systems in an integrated healthcare system.

BACKGROUND: Endologix issued important safety updates for the AFX Endovascular AAA System in 2016 and 2018 owing to the risk of type III endoleaks. Outcomes with these devices are limited to small case series with short-term follow-up. We describe the midterm outcomes for a large cohort of patients who received an Endologix AFX or AFX2 device. STUDY DESIGN: Data from an integrated healthcare system's implant registry, which prospectively monitors all patients after endovascular aortic repair, was used for this descriptive study. Patients undergoing endovascular aortic repair with three AFX System variations (Strata [AFX-S], Duraply [AFX-D], and AFX2 with Duraply [AFX2]) were identified (2011-2017). Crude cumulative event probabilities for endoleak (types I and III), major reintervention, conversion to open, rupture, and mortality (aneurysm related and all cause) were estimated. RESULTS: Among 605 patients, 375 received AFX-S, 197 received AFX-D, and 33 received AFX2. Median follow-up for the cohort was 3.9 (interquartile range, 2.5-5.1) years. The crude 2-year incidence of overall endoleak, any subsequent reintervention or conversion, and mortality was 8.8% (95% confidence interval [CI], 6.3-12.3), 12.0% (95% CI, 9.1-15.9), and 8.8% (95% CI, 6.3-12.2) for AFX-S. Respective estimates for AFX-D were 7.9% (95% CI, 4.8-13.0), 10.6% (95% CI, 6.9-16.1), and 9.7% (95% CI, 6.3-14.7); for AFX2, they were 14.1% (95% CI, 4.7-38.2), 16.2% (95% CI, 6.4-37.7), and 21.2% (95% CI, 10.7-39.4). CONCLUSIONS: The midterm outcomes of a large U.S. patient cohort with an Endologix AFX or AFX2 System demonstrate a concerning rate of adverse postoperative events. Patients with these devices should receive close clinical surveillance to prevent device-related adverse events.

Amplatzer Vascular Plug Embolization in Two Patients with Ruptured Infrarenal Aortic Aneurysm and Aortoiliac Occlusive Disease.

Mortality for ruptured abdominal aortic aneurysm (AAA) is known to be high. When left untreated, it is nearly always fatal. Standard treatment options include open surgery and endovascular aneurysm repair (EVAR), but both techniques have limitations. Owing to comorbidities and anatomical constraints, some patients are deemed unsuitable for both open surgery and EVAR. In these patients, alternative treatment strategies can be of special interest. To our knowledge, these are the first two cases reported using an Amplatzer Vascular Plug II for aortic embolization in patients with coexisting aneurysmatic and aorto-bi-iliac occlusive disease requiring urgent treatment for contained AAA rupture. Successful aneurysm exclusion was noted at follow-up ranging from 5 months to 3 years, and no procedure-related complications occurred. We therefore believe that in selected patients, this could be an elegant alternative in life-threatening situations with sustained occlusion in the mid-term.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) for Use in Temporizing Intra-Abdominal and Pelvic Hemorrhage: Physiologic Sequelae and Considerations.

REBOA has been used for several years by acute care surgeons for temporization of intra-abdominal, pelvic, and junctional hemorrhage. The physiology and consequences of aortic occlusion in these patients are largely unstudied.

A Late Post-EVAR Rupture in a 102-Year-Old Patient Related to a Type II Endoleak.

PURPOSE: Endovascular abdominal aortic aneurysm repair (EVAR) is progressively being applied in the elderly population. Type II endoleaks are common and mostly benign, but they are related to more aneurysm sac expansion after EVAR. They may lead to rupture in <1% of cases. We present a case of a centenarian with a post-EVAR rupture, related to type II endoleak, and discuss the use of EVAR on the management of this type of endoleak in an extremely old patient. CASE PRESENTATION: A 102-year-old man with a history of EVAR 12 years earlier, presented to the emergency department with a drop of consciousness. A computed tomography revealed a ruptured abdominal aortic aneurysm. Angiography showed a type II endoleak related to patent lumbar arteries deriving from collateral branches of the right internal iliac artery. Embolization was not successful and subsequently the ostium of the iliolumbar artery was overstented, obliterating the feeding branch. The postoperative course was complicated by a deterioration of chronic obstructive pulmonary disease and patient was discharged home on the seventh postprocedural day; nonetheless, he died on postoperative day sixteenth due to respiratory complications. CONCLUSION: Complications following EVAR are a real threat and emphasize the need for follow-up. The current case report shows that age per se should not be a contraindication for EVAR nor for follow-up. Also, late ruptures due to type II endoleaks could be treated in the very elderly population although larger series are required for robust conclusions.

Feasibility and Safety of Sac Embolization Using N-Butyl Cyanoacrylate in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysms or Isolated Iliac Artery Aneurysms.

PURPOSE: To evaluate the feasibility and safety of sac embolization with N-butyl cyanoacrylate (NBCA) in emergency endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (AAA) and iliac artery aneurysm (IAA) in comparison to EVAR without sac embolization. MATERIALS AND METHODS: Between February 2012 and December 2019, among 44 consecutive patients with ruptured AAA or IAA, 29 underwent EVAR. Of these, 22 patients (median age 77.5 years; 18 men) had concomitant sac embolization using NBCA; the remaining 7 patients (median age 88 years; 6 men) underwent EVAR without sac embolization and form the control group. The technical success, clinical success (hemodynamic stabilization), procedure-related complications, and mortality were compared between the groups. RESULTS: All EVAR procedures and embolizations were successful. The clinical success rates in the NBCA and control groups were 95% (21/22) and 71% (5/7), respectively (p=0.14). There was no complication related to the procedure. Type II endoleak occurred in 4 of 21 patients (19%) in the NBCA group vs none of the control patients. One patient (5%) died in the NBCA group vs 3 (43%) in the controls (p=0.034). CONCLUSION: Sac embolization using NBCA in emergency EVAR appears to be feasible and safe for ruptured AAA and IAA.

Inherited Thoracic Aortic Disease: New Insights and Translational Targets.

Inherited thoracic aortopathies denote a group of congenital conditions that predispose to disease of the thoracic aorta. Aortic wall weakness and abnormal aortic hemodynamic profiles predispose these patients to dilatation of the thoracic aorta, which is generally silent but can precipitate aortic dissection or rupture with devastating and often fatal consequences. Current strategies to assess the future risk of aortic dissection or rupture are based primarily on monitoring aortic diameter. However, diameter alone is a poor predictor of risk, with many patients experiencing dissection or rupture below current intervention thresholds. Developing tools that improve the risk assessment of those with aortopathy is internationally regarded as a research priority. A robust understanding of the molecular pathways that lead to aortic wall weakness is required to identify biomarkers and therapeutic targets that could improve patient management. Here, we summarize the current understanding of the genetically determined mechanisms underlying inherited aortopathies and critically appraise the available blood biomarkers, imaging techniques, and therapeutic targets that have shown promise for improving the management of patients with these important and potentially fatal conditions.

Spontaneous Aortoesophageal Fistula And Ruptured Aortic Aneurysm - A Case Report On Combined Aortic And Esophageal Prosrhesis Palliative Treatment.

Aortoesophageal fistulas are uncommon, dreadful vascular events, most frequently found in the setting of thoracic aorta aneurysms. Patients usually present with thoracic pain, dysphagia and sentinel hematemesis - the Chiari triad - followed by life threatening hematemesis. Emergent open surgery with debridement of necrotic tissue and in situ aortic graft repair is currently the best strategy. However, in patients which cannot withstand surgery, endovascular repair is currently gaining acceptance as a palliative treatment or as a bridge to surgery. We present a case of a 55-year-old female with a past of heavy alcohol abuse and a previously unknown massive aortic aneurysm, who presented to the emergency department complai- ning of acute dysphagia and epigastric pain. An abdominal ultrasound revealed left pleural effusion and suspected clots in the pleural space. A thoracic CTA was promptly done, where a spontaneous ruptured aortic aneurysm with aortoesophageal fistula was discovered. The team, fearing open surgery due to poor cardiac function, opted for a thoracic endovascular aortic repair. The aortoesophageal fistula dissected the esophageal wall in all of its thickness without rupture into the lumen. This was complicated with esophageal ischemia, aneurysmal sac infection and mediastinitis. Because the patient was in shock, in order to help control the infection, an esophageal prosthesis was placed, followed by proximal esophagostomy, distal esophageal closure and gastrostomy. Six months after initial presentation, the patient died at the emergency room, shortly after reentering with massive hematemesis and hypovolemic shock of undetermined origin.

Management of ruptured sinus of valsalva for device closure in a patient with haemophilia.

The association of Hemophilia A and ruptured aneurysm of sinus of valsalva (RSOV) has never been reported to the best of our knowledge. We report the case of a 29-year-old male patient with Hemophilia type A who presented with a RSOV into right atrium (RA). The patient underwent device closure off the RSOV and received Factor VIII infusions to decrease blood loss. The peri-procedural management is being presented in this case report.

Outcomes of target vessel endoleaks after fenestrated-branched endovascular aortic repair.

OBJECTIVE: The objective of this study was to determine the incidence rate, outcomes, and risk factors of target vessel-related endoleaks after fenestrated-branched endovascular aortic repair (F-BEVAR) for pararenal aneurysms or thoracoabdominal aortic aneurysms (TAAAs). METHODS: We reviewed consecutive patients treated by F-BEVAR between 2007 and 2017. Target vessel endoleaks were identified by computed tomography angiography (CTA). Follow-up included CTA and duplex ultrasound before discharge, at 2 months, at 6 months, and annually thereafter. Primary endoleaks were detected by predismissal CTA; secondary endoleaks were absent on the first CTA and were identified during follow-up. End points were spontaneous resolution of primary endoleaks, secondary interventions, and aneurysm rupture. Multivariable analyses were performed for risk factors of target vessel endoleaks and predictors of spontaneous resolution. RESULTS: A total of 382 patients (mean age, 75 ± 8 years; 75% male) underwent F-BEVAR for 195 pararenal aneurysms and 187 TAAAs with 1204 renal-mesenteric arteries targeted by 981 fenestrations and 223 directional branches. Fifty-two target vessel endoleaks were identified in 41 patients; 41 were type IIIC (interattachment), 10 were type IC (distal bridging stent sealing zone), and 1 was type IIIB (bridging stent fabric tear). Thirty-three patients (9%) had primary target vessel endoleaks in 41 target vessels (3%). Eight patients (2%) developed 11 secondary target vessel endoleaks. Directional branches were more prone to primary endoleaks (13/223 [6%]) in comparison to fenestrations (28/981 [3%]; P = .03). However, branch endoleaks resolved more often spontaneously (11/14 [79%]) compared with fenestration endoleaks (14/38 [37%]; P = .008). Other risk factors for target vessel endoleaks included inner aortic diameter ≥30 mm at the target vessel origin, four or more targeted vessels, TAAA (for primary endoleaks), and physician-modified endograft (for secondary endoleaks). Four patients with primary endoleaks underwent successful reintervention before discharge, and 29 were observed with a mean follow-up of 24 ± 21 months. Of the 41 primary endoleaks, 25 resolved spontaneously in 20 patients (61%) at first follow-up with no recurrences. Of the observed endoleaks, 11 persisted in 9 patients, and 8 of those endoleaks were treated in 7 patients. All secondary target vessel endoleaks required reintervention. There was one possible aneurysm rupture attributed to persistent secondary target vessel endoleak. CONCLUSIONS: Target vessel endoleak on CTA at discharge occurs in 1 of 10 patients treated by F-BEVAR. Of these, two-thirds resolve spontaneously, especially those affecting directional branches. Among patients with a persistent endoleak, endovascular reintervention is usually successful and aneurysm rupture is rare.