A Single-Institution Case Series of Total Endovascular Relining for Type 3 Endoleaks in Traditional Endovascular Aneurysm Repair (EVAR) Grafts with Raised Bifurcations.

BACKGROUND: The endovascular repair of infrarenal abdominal aortic aneurysms can be performed with a wide variety of devices. Many of these grafts elevate the aortic bifurcation which can limit future repairs if the graft material fails thereby creating a type III endoleak to aorto-uniliac grafts. Many manufacturers have grafts susceptible to this, but we have seen this in the Medtronic AneuRx graft. Our goal is to provide technical details and outcomes regarding a novel technique to reline these grafts while maintaining inline flow to the iliac arteries. METHODS: This was a single-institution review of patients who had endoleaks requiring intervention after a previously placed graft with an elevated aortic bifurcation. Primary outcomes included technical success defined as placement of all planned devices, resolution of type III endoleak, aneurysm size at follow-up, and requirement of reintervention. Secondary outcomes included 30-day complications, aneurysm-related mortality, and all-cause mortality. Technical details of the operation include back-table deployment of an Ovation device, modification of the deployment system tether and pre-emptive placement of an up and over 0.014″ wire. The wire is placed up and over and hung outside the contralateral gate. Once the main body is introduced above the old graft, the 0.014" is snared from the contralateral side and externalized. The main body is then able to be seated at the bifurcation as the limb is not fully deployed and then device deployment is completed per instructions for use. RESULTS: Our study consists of 4 individuals, 3 of which had an abdominal aortic aneurysm initially managed with an AneuRx endovascular aneurysm repair and 1 with a combination of Gore and Cook grafts. All 4 patients were male with an average age of 84.5 years at time of reline. All patients had at least 10 years between initial surgery and reline at our institution. Primary outcomes revealed no type 1 or 3 endoleaks at follow-up, technical success was 100% and 1 patient required reintervention for aneurysm growth and type 2 endoleak. In terms of our secondary outcomes, there was 1 postoperative complication which was cardiac dysfunction secondary to demand ischemia, aneurysm-related mortality was 0% and all-cause mortality was 25% at average follow-up of 2.44 years. CONCLUSIONS: As individuals continue to age, there are more patients who would benefit from less invasive reinterventions following endovascular aneurysm repair. Whether this is due to aortic degeneration, stent migration, or stent material damage is not always known. In this study, we present an endovascular approach to treating type III endoleak patients with a previous graft and elevated aortic bifurcation using Ovation stent grafts and found no evidence of type 1 or 3 endoleaks on follow-up imaging. This approach may allow patients with type III endoleak the option of a minimally invasive, percutaneous approach where they previously would not have had one.

Upper Extremity Access Has Worse Outcomes in F/BEVAR Using the VQI Dataset.

BACKGROUND: Physician-modified endografts and custom-manufactured devices use branched and fenestrated techniques (F/BEVAR) to repair complex aneurysms. Traditionally, many of these are deployed through a combination of upper and lower extremity access. However, with newer steerable sheaths, you can now simulate upper extremity (UEM) access from a transfemoral approach. Single-institution studies have demonstrated increased risks of access site complications and stroke when UEM access is used. This study compares outcomes after F/BEVAR in a national database between total transfemoral (TTF) access and mixed UEM access. METHODS: This study is an analysis of the Vascular Quality Initiative for all patients who underwent F/BEVAR from 2014 to 2021. Patients were stratified based on a TTF delivery of all devices versus any UEM access for deployment of target vessel stents. Primary outcomes included stroke, myocardial infarction (MI), and perioperative death. Secondary outcomes included access site hematoma, occlusion or embolization, operative time, fluoroscopy time, and technical success. Multivariable linear and logistic regression analyses were performed. RESULTS: Three thousand one hundred forty six patients underwent an F/BEVAR: 2,309 (73.4%) TTF and 837 (26.6%) UEM. Logistic regression analysis indicated a two-fold increased risk of death and MI and a three-fold increased risk of stroke in the UEM group. Furthermore, there is decreased operative time (221 vs. 297 min, P < 0.001) and fluoroscopy time (62 vs. 80 min, P < 0.001) in the TTF group and no difference in technical success between groups (96% vs. 97%, P = 0.159). Finally, there was a decrease in access site hematoma 2.54% vs. 4.31% (P = 0.013), access site occlusion 0.61% vs. 1.91% (P = 0.001), and extremity embolization 2.17% vs. 3.58% (P = 0.026) in the TTF versus UEM group. CONCLUSIONS: This study using Vascular Quality Initiative data demonstrates that patients who undergo an F/BEVAR using UEM access have an increased risk of perioperative MI, death, and stroke compared to TTF access.

Use of surgical augmented intelligence maps can reduce radiation and improve safety in the endovascular treatment of complex aortic aneurysms.

OBJECTIVE: The introduction of endovascular procedures has revolutionized the management of complex aortic aneurysms. Although repair has traditionally required longer operative times and increased radiation exposure compared with simple endovascular aneurysm repair, the recent introduction of three-dimensional technology has become an invaluable operative adjunct. Surgical augmented intelligence (AI) is a rapidly evolving tool initiated at our institution in June 2019. In our study, we sought to determine whether this technology improved patient and operator safety. METHODS: A retrospective review of patients who had undergone endovascular repair of complex aortic aneurysms (pararenal, juxtarenal, or thoracoabdominal), type B dissection, or infrarenal (endoleak, coil placement, or renal angiography with or without intervention) at a tertiary care center from August 2015 to November 2021 was performed. Patients were stratified according to the findings from intelligent maps, which are patient-specific AI tools used in the operating room in conjunction with real-time fluoroscopic images. The primary outcomes included operative time, radiation exposure, fluoroscopy time, and contrast use. The secondary outcomes included 30-day postoperative complications and long-term follow-up. Linear regression models were used to evaluate the association between AI use and the main outcomes. RESULTS: During the 6-year period, 116 patients were included in the present study, with no significant differences in the baseline characteristics. Of the 116 patients, 76 (65.5%) had undergone procedures using AI and 40 (34.5%) had undergone procedures without AI software. The intraoperative outcomes revealed a significant decrease in radiation exposure (AI group, 1955 mGy; vs non-AI group, 3755 mGy; P = .004), a significant decrease in the fluoroscopy time (AI group, 55.6 minutes; vs non-AI group, 86.9 minutes; P = .007), a decrease in the operative time (AI group, 255 minutes; vs non-AI group, 284 minutes; P = .294), and a significant decrease in contrast use (AI group, 123 mL; vs non-AI group, 199 mL; P < .0001). No differences were found in the 30-day and long-term outcomes. CONCLUSIONS: The results from the present study have demonstrated that the use of AI technology combined with intraoperative imaging can significantly facilitate complex endovascular aneurysm repair by decreasing the operative time, radiation exposure, fluoroscopy time, and contrast use. Overall, evolving technology such as AI has improved radiation safety for both the patient and the entire operating room team.

A Single Center Review of a Total Transfemoral Approach to Upper Extremity Access in Branched and Fenestrated Physician Modified Endografts.

BACKGROUND: Aortic aneurysms are normally treated by an endovascular approach. Due to the lack of devices and increasing experience, there is a growing number of complex aneurysms undergoing repair by physician modified endografts (PMEGs). Previously, our practice was to target visceral vessels exclusively through upper extremity access. We have since then shifted to an all transfemoral approach when possible. This study aims to show the operative benefits of transfemoral only approaches. METHODS: Patients who underwent a PMEG at a tertiary center between 2015 and 2020 were included. Patients were stratified into 2 groups based on branched vessel approach-transfemoral only versus axillary or composite (axillary and femoral). Forty-one patients had a pararenal or type IV thoracoabdominal aortic aneurysm (TAAA) and 15 patients had more complex TAAA. Primary outcomes were operative time, radiation exposure, fluoroscopy time, contrast, and blood loss. Secondary outcomes were 30-day mortality and major adverse events. Linear regression models were used to evaluate the association between approach type and the main outcomes. RESULTS: Fifty-six patients were included with 48% (n = 27) in the transfemoral group and 52% (n = 29) in the axillary/composite group. Baseline characteristics were similar between the groups. Intraoperative outcomes revealed significant increase in the average operative time (418 vs. 246 min, P < 0.001), in radiation exposure (2,755 vs. 1,740 mGy, P = 0.03), in fluoroscopy time (108 vs. 74 min, P = 0.01) and in blood loss (579 vs. 202 cc, P = 0.002) in the axillary/composite group compared to the transfemoral group. There was no significant difference in 30-day mortality or major adverse events including stroke. CONCLUSIONS: This study shows a transfemoral approach to complex endovascular aortic aneurysm repair as opposed to axillary/composite approach has decreased operative time, radiation exposure, and fluoroscopy time and no significant differences in 30-day mortality or major adverse events. When treating complex aneurysms, improving efficiency is important to minimize morbidity to patients and operators.

Resurrection of Chronically Occluded Prosthetic Bypass Grafts in a Single Stage with Suction Thrombectomy and Intervention.

BACKGROUND: Peripheral arterial occlusive disease (PAOD) continues to be a vexing problem despite the advent of endovascular techniques augmenting traditional open repair. At our institution, we have found there is a growing number of patients with PAOD who are vein-challenged and have undergone prosthetic bypass previously for infrainguinal arterial reconstruction. When occluded, these grafts have been abandoned for a new bypass strategy or amputation. We present a novel technique of reestablishing flow through chronically occluded prosthetic bypass grafts. METHODS: A retrospective review of a prospectively maintained database compiled at 2 institutions between 2016 and 2019 was performed. Six patients had previous prosthetic bypass grafts with 4 patients having femoral to popliteal grafts, 1 patient with a femoral to femoral graft, and 1 with a femoral to posterior tibial bypass graft. All patients had an attempted single-stage intervention to clear chronically occluded grafts. RESULTS: A total of 6 patients were included in the study. Indications for intervention were chronic, critical limb ischemia with tissue loss (3), severe claudication (2), and acute on chronic limb ischemia (1). Average time from bypass to suction thrombectomy was 29 months (6-60 months). Mean patency duration is 13 months (1-28 months). Adjunctive procedures include overnight lysis to improve outflow in 1 patient (16.6%), drug-coated balloon angioplasty (83.3%), or stents (83.3%). There were no embolic complications during these procedures. All (2) wounds healed and all are maintained on full-dose anticoagulation and/or antiplatelet therapy. CONCLUSIONS: Often, the timing of bypass graft occlusion is unknown, and the risk of embolism with lysis for chronically occluded bypass grafts is concerning with traditional peripheral intervention techniques. We report a new and unique minimally invasive approach to resurrect chronically occluded prosthetic bypass grafts often successful in just one stage. This tool offers an alternative technique for limb salvage in complex patients and as use increases, requires further interrogation.

Common Iliac Artery Aneurysm Repair with Hypogastric Preservation via Balloon-Expandable Covered Stents Using the Eyelet Technique-Iliac Branched Devices Still Inappropriate in Many Patients.

BACKGROUND: Common iliac artery aneurysms (CIAAs) are seen in 20-40% of patients with abdominal aortic aneurysms. Historically treated with sacrifice of the hypogastric artery, which can result in significant morbidity related to pelvic ischemia, new devices have made hypogastric artery preservation more feasible but are only applicable to a small subset of aneurysm anatomy. We sought to assess the safety and efficacy or a novel technique for hypogastric artery preservation applicable to a wider variety of patients with CIAAs. METHODS: We conducted a retrospective review of a prospectively maintained database of all patients with CIAAs treated with a novel endovascular technique at the UC San Diego Sulpizio Cardiovascular Center or the San Diego Veterans Affairs Hospital between March 2016 and December 2017. The endovascular technique involved stent placement in both the internal and external iliac arteries, with balloon expansion to minimize gutters between the endografts. Primary end points included technical success, limb patency, and presence of endoleaks (ELs). RESULTS: A total of 14 limbs (12 patients) were treated for CIAAs with 100% technical success and limb patency at an average of 6.8 months of follow-up. No patients experienced type I or type III ELs or evidence of pelvic ischemia. Two patients required reintervention, and one patient died of causes unrelated to the procedure. CONCLUSIONS: This technique was performed with excellent short- and mid-term safety in patients with varying aneurysm anatomy. The high rates of technical success and low rate pelvic ischemia represent improvement over conventional techniques that sacrifice the hypogastric artery and warrant further testing in a larger patient series with longer term follow-up.

Vertebral Artery Stump Syndrome Due to Chronic Complicated Aortic Dissection.

BACKGROUND: Vertebral artery (VA) stump syndrome arises when thrombi of an occluded proximal VA propagate to the brain and cause posterior circulation strokes. This phenomenon has been described in limited reports to date. CASE DESCRIPTION: A 39-year-old man with a remote history of endovascular repair of a type B aortic dissection experienced type Ia endoleak causing expansion of the false lumen associated with the dissection. This required combined open debranching and endovascular reconstruction of the thoracic aortic arch. He experienced recurrent posterior circulation strokes 6 months postoperatively. The left VA origin was occluded and remained sequestered to the proximal subclavian artery, in continuity with the false lumen of the dissection. We suspected the aortic dissection extended into the VA and caused the occlusion, while pressure from the false lumen propelled thrombi from the occluded VA stump into the posterior circulation. Repeat imaging shortly after symptom onset showed spontaneous recanalization of the VA. Open surgical ligation of the proximal left VA led to symptom resolution. CONCLUSIONS: We describe a unique mechanism of VA stump syndrome due to VA occlusion and pressure waves from an aortic dissection and present the first report of VA stump syndrome treatment by surgical exclusion of the VA.

Midterm evaluation of perigraft arterial sac embolization in endovascular aneurysm repair.

OBJECTIVE: Management of clinically significant endoleaks (ELs) remains costly, time-consuming, and morbid. Unresolved ELs can result in rupture and mortality after endovascular aneurysm repair (EVAR). Perigraft arterial sac embolization (PASE) has been used to treat ELs diagnosed at the time of EVAR or during surveillance. METHODS: A retrospective review of prospectively maintained databases was conducted. The databases were compiled from two institutions between 2006 and 2016. PASE was performed for type I, type II, or type III EL with a thrombin, contrast medium, and Gelfoam (Pfizer, New York, NY) slurry prepared as previously described. PASE was administered either at the time of EVAR (primary) or during surveillance (secondary). Safety end points included nontarget embolization, defined as neurologic or enteric clinical sequelae from lumbar artery or visceral artery embolization, allergic reaction, peripheral embolization, or rupture. Efficacy end points included successful resolution of EL and cessation of aneurysm sac growth on computed tomography (CT) scans with contrast enhancement. RESULTS: A total of 66 patients included in the study were treated with PASE. Primary PASE was performed in 38 patients (58%) and secondary in 28 (42%). Within the total cohort, the average clinical and CT scan follow-up was 1.7 years (0.1-11.6 years). Four patients required open repair for residual high-pressure ELs (one type IIIB and three type I; 6%). Of the 95% of patients who did not require open conversion, aneurysm growth did not occur during the follow-up period. In the overall cohort, PASE was successful in 88% of type I EL and 73% of patients with type II EL. There was no evidence of recanalization after thrombosis of culprit vessel for EL. No patients suffered nontarget embolization, spinal ischemia, allergic reaction, post-EVAR rupture, or colonic ischemia. CONCLUSIONS: Primary and secondary PASE proved to be a safe, effective, and durable tool in sac management in conjunction with EVAR. Treating ELs during or after EVAR with PASE has minimized the incidence of EL on CT scan and halted aneurysm growth in our cohort. Further studies are needed to confirm the long-term durability of PASE in reducing secondary interventions after EVAR.

Proper technical procedures improved outcomes in a retrospective analysis of EVAS FORWARD IDE trial 3-year results.

OBJECTIVE: Adverse outcomes observed late in the Nellix EndoVascular Aneurysm Sealing (EVAS) System (Endologix, Inc, Irvine, Calif) investigational device exemption trial prompted refinement of the anatomic instructions for use (IFU). This study aimed to investigate the association of procedural factors during Nellix endograft deployment and patient outcomes. METHODS: We retrospectively reviewed 1-month imaging of 333 patients enrolled in the prospective, multicenter EVAS investigational device exemption trial between January 2014 and September 2016. Initial observations of those patients who met revised anatomic IFU yet still experienced late adverse events suggested that inadequate seal and low graft placement were common among these patients. Key procedural variables identified from a univariate analysis were applied to construct four cohorts stratified by procedural technical performance (technically adequate [P+] or technically inadequate [P-]) and the revised anatomic indications for use (anatomically within IFU [A+] or anatomically outside of IFU [A-]) and to compare them for aneurysm-related outcomes. A logistic regression analysis was performed to identify significant predictors of sac expansion or migration. RESULTS: Proximal and distal seal zones and low graft placement were identified by logistic regression analysis as significant predictors of sac expansion or migration. Accordingly, acquisition of ≥10-mm proximal and distal seal zones and the position of the lowest stent within 10 mm of the lowest renal artery were clinically justified as thresholds for a technically adequate procedure. Patients who did not achieve these parameters were deemed to have a technically inadequate procedure. By use of the proposed procedural adequacy criteria and established anatomic criteria, patients were stratified into four cohorts: A+/P+ (n = 77), A+/P- (n = 54), A-/P+ (n = 71), and A-/P- (n = 131). Three-year estimates of freedom from migration of 10 mm were 98.6% in A+/P+, 95.9% in A+/P-, 85.8% in A-/P+, and 80.1% in A-/P-; freedom from type IA endoleak estimates were 98.6% in A+/P+, 100% in A+/P-, 96.4% in A-/ P+, and 90.3% in A-/P- cohorts. Freedom from sac expansion and secondary intervention were 96.9% and 90.6% in A+/P+, 86.0% and 93.6% in A+/P-, 87.1% and 83.1% in A-/P+, and 80.5% and 79.8% in A-/P- groups, respectively. Two early deaths (aneurysm-related mortality) on days 4 and 12 postoperatively were reported within the A+/P- group. Kaplan-Meier estimates of freedom from all-cause mortality and aneurysm-related mortality at 3 years were similar between cohorts. CONCLUSIONS: This post hoc analysis suggests that achieving a 10-mm proximal and distal seal with adequate positioning of the endograft with respect to the renal arteries is associated with improved patient outcomes.

Hospital Volume Impacts the Outcomes of Endovascular Repair of Thoracoabdominal Aortic Aneurysms.

BACKGROUND: Few centers in the United States have the expertise to manage patients with a thoracoabdominal aortic aneurysm (TAAA). The purpose of this study is to use a nationally representative vascular database to assess the role of hospital volume on outcomes in patients undergoing endovascular repair for TAAA. METHODS: All patients undergoing complex endovascular repair (cEVAR) for TAAA were identified in the Vascular Quality Initiative (VQI) database (2012-2018). The total mean number of cases per year was identified at each center and were used to group into three quantiles containing an equal number of patients (Low [LVH], Medium [MVH], High [HVH]). Standard univariate and multivariable (logistic regression) analyses were performed to evaluate the patient's characteristics and short-term outcomes. RESULTS: A total of 2,115 patients from 118 centers (Low - 92, Medium - 19, High - 7) were identified in VQI from 2012 to 2018. The annual mean (S.D.) number of cases at HVH, MVH, LVH were 22.7 (4.7), 9.6 (3.0), 3.6 (1.4), respectively. The repair of Type III TAAA was slightly higher in HVH versus MVH versus LVH (22.5% vs. 21.0% vs. 15.1%), while Type I was more common among LVH versus MVH versus HVH (13.7% vs. 11.5% vs. 3.7%) (Both P < 0.001). Custom/modified devices were more likely to be used in HVH versus MVH versus LVH (67.9% vs. 27.6% vs. 27.2%) (P < 0.001). Additionally, HVH and MVH utilized fenestrated/branched or chimney/snorkel options more frequently, whereas surgical bypasses were common in LVH for revascularization of visceral arteries. In univariate analysis, HVH were associated with significantly lower mortality (2.2% vs. 5.1% and 6.5%), failure to rescue [FTR] (3.5% vs. 11.6% and 12.1%) and any complication (24.6% vs. 27.1% and 31.2%) compared to LVH and MVH (All P < 0.001). After adjusting for potential confounders, both LVH and MVH were associated with 2-4 fold increase in the odds of mortality [OR (95% CI): 2.30 (1.20-4.41) and 2.14 (1.16-3.93)] and FTR [OR (95% CI): 4.42 (1.86-10.54) and 4.08 (1.73-9.62)] compared to HVH. CONCLUSIONS: Our study demonstrates significantly lower morbidity and mortality in high volume hospitals performing cEVAR for TAAA, despite operating on older patients with more complex TAAA types. This is likely due to better rescue phenomenon in addition to more experienced operators. Complex endovascular repair of TAAA can be performed safely in high volume aortic centers of excellence.

Endovascular Aneurysm Sealing is Associated with Higher Medium-Term Survival than Traditional EVAR.

BACKGROUND: Endovascular aneurysm repair (EVAR) is the dominant treatment modality for abdominal aortic aneurysm (AAA). Periprocedural risks are low, and cardiovascular events are the principle determinants of long-term survival. Recently, the concept of endovascular aneurysm sealing (EVAS) has been introduced into clinical investigation. In previous cohort studies, EVAS has been associated with a lower all-cause mortality than expected despite device issues. We used a propensity weighted approach to investigate whether EVAS was associated with lower all-cause mortality after aneurysm repair. METHODS: We compared 333 patients in the Nellix United States Investigational Device Exemption trial to 15,431 controls from the Vascular Quality Initiative between 2014 and 2016 after applying the exclusion criteria from the investigational device exemption (hemodialysis, creatinine > 2.0 mg/dL, or rupture). We calculated propensity scores and applied inverse probability weighting to compare risk adjusted medium-term survival using Kaplan-Meier and Cox regression. RESULTS: After weighting, patients treated with the Nellix EVAS system experienced higher 3-year survival than controls from the Vascular Quality Initiative (93% vs. 88%, respectively). This corresponded to a 41% lower risk of mortality for EVAS compared with EVAR (HR 0.59 [0.38-0.92], P = 0.02). Subgroup analysis demonstrated that the association between EVAS and higher survival was strongest in the subgroup of patients with aneurysms over 5.5 cm (P for interaction < 0.001). In this subgroup, EVAS patients experienced half the rate of mortality as those patients treated with EVAR, with 3-year survival of 92% compared with 86% (HR 0.5 [0.3-0.9], P = 0.02). CONCLUSIONS: In this select group of patients, EVAS was associated with higher medium-term survival than traditional EVAR. Although issues with the device have recently surfaced, this exploratory analysis shows that the concept of sac sealing may hold promise. Further study is needed to confirm this finding and determine whether EVAS is associated with lower rates of cardiovascular events.

External Iliac Occlusion Does Not Preclude Endovascular Management of Aortoiliac Disease-Technique and Evolution of Therapy.

BACKGROUND: Controversy remains over how to best manage chronic total occlusions of the aortoiliac (AI) system. Uncovered stents are the traditional choice but offer less durability in theory with the risk of stent ingrowth. External iliac artery (EIA) occlusions are challenging due to access difficulty. METHODS: We performed a retrospective study of patients who had undergone endovascular AI intervention between December, 2014 and March, 2017 for Trans-Atlantic Inter-Society Consensus D lesions. The primary study end point was overall survival. Secondary end points included primary assisted or secondary patency and procedural complications. RESULTS: Twenty-one patients were identified in the 22-month period that underwent recanalization of at least 1 iliac segment, using Atrium iCAST in the aorta and common iliac segments and/or Viabahn stents in the external iliac arteries. Overall AI patency was 100% (mean 6.8 months). Six AI bifurcation advancements were performed (primary patency 100%, mean 8 months). Eight patients with EIA occlusion underwent total percutaneous revascularization (primary patency 88%, secondary patency 100% mean 6 months). Five outflow procedures were performed concurrent to the AI recanalization. Two patients (15.4%) died of cardiovascular events. No access site complications were observed in the cohort. CONCLUSIONS: AI occlusive disease remains a surgical challenge. Although uncovered stents are a common therapy for revascularization of this vascular bed, our experience with balloon-expanding and self-expanding covered stents suggests they may be used to good effect with minimal complications in the intermediate term.

Endovascular Management of a Large Persistent Sciatic Artery Aneurysm.

The persistent sciatic artery (PSA) is a remnant of the fetal circulatory system that is preserved in less than 0.1% of the population. Up to 60% of patients with this vascular anomaly will go on to development of a PSA aneurysm (PSAA), which can produce a variety of symptoms including neuropathy, claudication, and acute limb-threatening ischemia. Historical management is by open operation and interposition grafting, which can be highly morbid. We describe successful management of a large, symptomatic PSAA by endovascular stent grafting with intermediate term follow-up.

Refinement of anatomic indications for the Nellix System for endovascular aneurysm sealing based on 2-year outcomes from the EVAS FORWARD IDE trial.

BACKGROUND: The Nellix System (Endologix, Inc, Irvine, Calif) for endovascular aneurysm sealing (EVAS) is a novel approach to abdominal aortic aneurysm treatment and conceptually different from endovascular aneurysm repair, whereby polymer is employed to fill and actively manage the abdominal aortic aneurysm sac. One-year safety and effectiveness results of the Nellix pivotal trial demonstrated encouraging outcomes with very low morbidity and mortality and high procedural and treatment success. Two-year imaging revealed a signal of migration, leading to a field safety notification issued by the manufacturer on October 21, 2016, and a dedicated root cause analysis, resulting in refinements to the instructions for use (IFU). We report the 2-year results of the investigational device exemption pivotal trial stratified according to the new and original criteria for selection of patients. METHODS: Comprehensive engineering evaluations, statistical analyses, and clinical assessments were conducted looking at patients enrolled in the pivotal trial (N = 150), roll-in cohort (N = 29), and continued access program (N = 154). All patients in all cohorts were treated on-IFU at the time of enrollment. Logistic regression models supported the mechanism that migration with Nellix is associated with a small aortic flow lumen relative to a large aneurysm thrombus burden and large aortic neck diameters. Based on these findings, refinements to the IFU criteria were applied, excluding patients with a thrombus index (maximum aneurysm sac/maximum flow lumen diameter) >1.4, aortic neck diameter >28 mm, and aortic neck conicity (>10% diameter change along the infrarenal neck) and requiring a 10-mm distal seal zone in the iliac artery. RESULTS: Freedom from all-cause mortality at 2 years was 94%. Patient outcomes were then stratified on the refined morphologic criteria and analyzed retrospectively. Two-year freedom from composite endoleak was high among both cohorts (95% on-IFU vs 92% off-IFU). Freedom from migration was 97.7% on-IFU vs 93.2% off-IFU (P = .0125). Freedom from aneurysm enlargement was 98.1% on-IFU vs 93.5% off-IFU (P value is not available because of failure of log-rank test assumptions). Composite freedom from migration, type IA endoleak, or aneurysm expansion was 95.9% among the on-IFU cohort vs 85.1% in the off-IFU cohort (P = .0017). CONCLUSIONS: Consistent with the introduction of a novel therapy, the presentation of failure modes of EVAS over time was inevitable. Using detailed imaging as well as engineering and statistical analysis, we were able to understand risk factors for adverse events specific to EVAS and defined those patients best suited for Nellix. With this EVAS-specific approach to defining IFU, on-IFU patients were identified as those with large aneurysms with little thrombus that would be prone to type II endoleaks and sac expansion with traditional devices. When treated with Nellix, these patients were predicted to experience exceptional results, especially with regard to a low composite endoleak rate and low all-cause mortality.

Dialysis Access Hemorrhage: Access Rescue from a Surgical Emergency.

BACKGROUND: Hemorrhage from a dialysis access can be a life-threatening condition. This study details our experience using access rescue strategies, including in situ graft replacement, primary repair, or conversion to an autogenous fistula, coupled with treatment of central vein occlusion to maintain access usage in patients presenting with conduit hemorrhage. METHODS: During a 3-year period (2012-2014), 26 patients (14 women, 12 men) on chronic hemodialysis were treated for access conduit bleeding (n = 18) or life-threatening hemorrhage (n = 8), located in the upper extremity (n = 23) or thigh (n = 3). All patients had developed bleeding from a skin eschar/ulcer over a bovine (n = 9) or polytetrafluoroethylene (n = 9) bridge graft, or aneurysmal autogenous fistula (n = 8). A retrospective review of outcome relative to clinical signs, etiology of conduit bleeding (infection, wall erosion), and the type of rescue procedure(s) was performed. Duplex ultrasound testing was used to guide therapy based on the presence of aneurysmal degeneration, perigraft fluid, or access flow pattern indicative of venous outflow obstruction. RESULTS: One-half of the patients were taken emergently to the operating room for hemorrhage control or impending rupture of an infected false aneurysm, the remaining repaired on an urgent basis. In 18 patients, emergency room personnel attempted control of access site bleeding by suturing (n = 14) or tourniquet (n = 4). Dialysis access salvage was achieved in 22 (85%) of 26 patients by in situ conduit replacement using a rifampin-soaked polytetrafluoroethylene conduit (n = 19) or primary repair (n = 3). Two patients with sepsis and ruptured, infected false aneurysm were treated by ligation, and 2 patients with nonsalvable access had conversion to an autogenous fistula. One-third of rescued accesses (n = 7) had staged endovascular treatment of central vein stenosis. One patient died within 30 days. All dialysis access revisions remained patent and used for immediate dialysis (n = 5), within 4-5 weeks (n = 19), or after vein maturation (n = 2). One replaced graft was revised for infection. Positive blood or bleeding site cultures were obtained from 9 (45%) of 20 patients tested. CONCLUSIONS: Salvage of a functional dialysis access is possible in the majority of patients presenting with conduit hemorrhage. Loss of wall integrity, infection, and venous hypertension were etiologic factors. Application of in situ graft replacement strategies known to be effective in the treatment of graft infection should be considered in the management of this surgical emergency.

Intervention after endovascular aneurysm repair: Endosalvage techniques including perigraft arterial sac embolization and endograft relining.

Endovascular aneurysm repair (EVAR) has revolutionized the treatment of abdominal aortic aneurysm (AAA). However, persistent AAA sac endoleak following EVAR can result in sac diameter increase requiring re-intervention in up to one-third of cases and even result in aneurysm rupture. In this case review, we summarize and detail endovascular re-interventions for each type of endoleak. We also detail specific options including stent-graft relining for indeterminate, Type III, and Type IV endoleaks and perigraft arterial sac embolization to induce thrombosis and resolve acute Type I, II, or III endoleaks. Endograft relining involves placement of a new stent-graft-elevating the bifurcation and extending the repair from renal artery to hypogastric arteries; perigraft arterial sac embolization involves placement of a catheter into the excluded sac from common femoral artery access, characterization of the inflow and outflow of the endoleak, and inducing cessation of the blood flow into the sac by the administration of thrombogenic material. Endoleaks range from low-pressure endoleaks, which can be safely monitored in a surveillance program to high-pressure endoleaks, which mandate intervention when associated with AAA sac diameter increase to protect from rupture. The evaluation of new devices and techniques to treat endoleak after EVAR remains an important issue in patient care after EVAR.

Congenital agenesis of inferior vena cava: a rare cause of unprovoked deep venous thrombosis.

Congenital anomalies of the inferior vena cava (IVC), although rare, are a risk factor for lower limb deep venous thrombosis (DVT). A 19-year-old male presented with a left flank and groin pain caused by iliofemoral venous thrombosis. Vascular imaging by computed tomography (CT) scanning and venography demonstrated agenesis of the IVC. Catheter-directed thrombolysis via a popliteal vein was attempted but did not alter the patency of the common femoral vein outflow collaterals into the retroperitoneal azygous venous system. The patient was anticoagulated using systemic heparin infusion and clinical symptoms resolved within 5 days. He was transitioned to oral Coumadin anticoagulation, and follow-up venous duplex testing demonstrated no infrainguinal DVT and phasic venous flow with respiration in the femoral vein indicating patent collateral veins. Anomalies of the IVC are present in 0.3-0.5% of otherwise healthy individuals. Agenesis of the IVC has an incidence of 0.0005-1% in the general population but is found in almost 5% of patients <30 years of age with unprovoked lower limb DVT. In adults, IVC agenesis anomaly can cause diagnostic problems in the paravertebral area because of the tumor-like appearance of the azygous venous collaterals on noncontrast CT imaging. In young adults presenting with unprovoked lower limb DVT, the presence of an IVC anomaly should be considered and evaluated for by venous duplex testing and if necessary CT venography.

Experience matters more than specialty for carotid stenting outcomes.

OBJECTIVE: The introduction of carotid stenting has led to a rapid rise in the number of vascular specialists performing this procedure. The Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) has shown that carotid stenting can be performed with an equivalent major event rate compared with carotid endarterectomy. However, there is still controversy about the appropriate training and experience required to safely perform this procedure. This observational study examined the performance of carotid stenting with regard to specialty and case volume. METHODS: From 2004 to 2011, inpatients diagnosed with carotid stenosis who had a carotid stenting procedure were extracted from the Nationwide Inpatient Sample database. The cohort was separated on the basis of the provider performing the procedure (surgeon vs interventionalist), hospital location, and volume. Surgeons were defined as providers who also performed either a carotid endarterectomy or femoral-popliteal bypass during the same time interval. Primary end points analyzed included stroke, myocardial infarction, and 30-day mortality. Length of stay and hospital costs were also analyzed as secondary outcomes. RESULTS: A total of 20,663 cases of carotid stenting were found; 15,305 (74%) cases were identified to be performed by a "surgeon," whereas 5358 (26%) were done by an "interventionalist." The majority of cases were done at hospitals in urban locations (96.51%) and designated teaching institutions (61.47%). Unadjusted outcomes were similar between surgeons and interventionalists in terms of stroke (4.33% and 4.41%), myocardial infarction (2.10% and 2.13%), and mortality (0.84% and 1.03%) respectively. Qualitatively, volume per 10 cases was shown to decrease the risk of stroke. Adjusted multivariate analysis demonstrated no statistical significance between primary end point outcomes. However, length of stay (2.81 vs 3.08 days) and total charges ($48,087.61 and $51,718.77) were lower for procedures performed by surgeons. CONCLUSIONS: Surgeons are performing the majority of carotid stent procedures in the United States. The volume of cases performed by a provider, rather than the provider's specialty, appears to be a stronger predictor of adverse outcomes for carotid stenting. There were, however, significant cost differences between surgeons and interventionalists, which needs to be further evaluated at an institutional level.

Staged Hybrid Endovascular Repair of a Ruptured Abdominal Aortic Aneurysm with Aortocaval Fistula.

There is a growing body of literature expanding the indication of endovascular aneurysm repair, from prophylactic treatment of aneurysms to other indications such as ruptured and complicated ruptured abdominal aneurysms. Concomitant aortocaval fistula is rare, and reports of open and endovascular repair exist. We report a unique hybrid approach to a case of a ruptured abdominal aortic aneurysm with aortocaval fistula, repaired primarily via endovascular approach in a hybrid, two-staged fashion. Representative images are presented in addition to a short review of this pathology.