A national census for the off-label treatment of complex aortic aneurysms.

OBJECTIVE: Despite regulatory challenges, device availability, and rapidly expanding techniques, off-label endovascular repair of complex aortic aneurysms (cAAs) has expanded in the past decade. Given the lack of United States Food and Drug Administration-approved endovascular technology to treat cAAs, we performed a national census to better understand volume and current practice patterns in the United States. METHODS: Targeted sampling identified vascular surgeons with experience in off-label endovascular repair of cAAs. An electronic survey was distributed with institutional review board approval from the University of Rochester to 261 individuals with a response rate of 38% (n = 98). RESULTS: A total of 93 respondents (95%) reported off-label endovascular repair of cAAs. Mean age was 45.7 ± 8.3 years, and 84% were male. Most respondents (59%) were within the first 10 years of practice, and 69% trained at institutions with a high-volume of off-label endovascular procedures for complex aortic aneurysms with or without a physician-sponsored investigational device exemption (PS-IDE). Twelve respondents from 11 institutions reported institutional PS-IDEs for physician-modified endografts (PMEGs), in-situ laser fenestration (ISLF), or parallel grafting technique (PGT), including sites with PS-IDEs for custom-manufactured devices. Eighty-nine unique institutions reported elective off-label endovascular repair with a mean of 20.2 ± 16.5 cases/year and ∼1757 total cases/year nationally. Eighty reported urgent/emergent off-label endovascular repair with a mean of 5.7 ± 5.4 cases/year and ∼499 total cases/year nationally. There was no correlation between high-volume endovascular institutions (>15 cases/year) and institutions with high volumes of open surgical repair for cAAs (>15 cases/year; odds ratio, 0.7; 95% confidence interval, 0.3-1.5; P = .34). Elective techniques included PMEG (70%), ISLF (30%), hybrid PMEG/ISLF (18%), and PGT (14%), with PMEG being the preferred technique for 63% of respondents. Techniques for emergent endovascular treatment of complex aortic disease included PMEG (52%), ISLF (40%), PGT (20%), and hybrid-PMEG/ISLF (14%), with PMEG being the preferred technique for 41% of respondents. Thirty-nine percent of respondents always or frequently offer referrals to institutions with PS-IDEs for custom-manufactured devices. The most common barrier for referral to PS-IDE centers included geographic distance (48%), longitudinal relationship with patient (45%), and costs associated with travel (33%). Only 61% of respondents participate in the Vascular Quality Initiative for complex endovascular aneurysm repair, and only 57% maintain a prospective institutional database. Eighty-six percent reported interest in a national collaborative database for off-label endovascular repair of cAA. CONCLUSIONS: Estimates of off-label endovascular repair of cAAs are likely underrepresented in the literature based on this national census. PMEG was the most common technique for elective and emergent procedures. Under-reported off-label endovascular repair of cAA outcomes data appears to be limited by non-standardized PS-IDE reporting to the United States Food and Drug Administration, and the lack of Vascular Quality Initiative participation and prospective institutional data collection. Most participants are interested in a national collaborative database for endovascular repair of cAAs.

Most privately insured patients do not receive federally recommended abdominal aortic aneurysm screening.

OBJECTIVE: Since 2005, the United States Preventative Services Task Force has recommended abdominal aortic aneurysm (AAA) ultrasound screening for 65- to 75-year-old male ever-smokers. Integrated health systems such as Kaiser Permanente and the Veterans Affairs (VA) health care system report 74% to 79% adherence, but compliance rates in the private sector are unknown. METHODS: The IBM Marketscan Commercial and Medicare Supplemental databases (2006-2017) were queried for male ever-smokers continuously enrolled from age 65 to 75 years. Exclusion criteria were previous history of AAA, connective tissue disorder, and aortic surgery. Patients with abdominal computed tomographic or magnetic resonance imaging from ages 65 to 75 years were also excluded. Screening was defined as a complete abdominal, retroperitoneal, or aortic ultrasound. A logistic mixed-effects model utilizing state as a random intercept was used to identify patient characteristics associated with screening. RESULTS: Of 35,154 eligible patients, 13,612 (38.7%) underwent screening. Compliance varied by state, ranging from 24.4% in Minnesota to 51.6% in Montana (P < .05). Screening activity increased yearly, with 0.7% of screening activity occurring in 2008 vs 22.2% in 2016 (P <.05). In a logistic mixed-effects model adjusting for state as a random intercept, history of hypertension (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.03-1.13), coronary artery disease (OR, 1.17; 95% CI, 1.10-1.22), congestive heart failure (OR, 1.14; 95% CI, 1.01-1.22), diabetes (OR, 1.1; 95% CI, 1.06-1.16), and chronic kidney disease (OR, 1.4; 95% CI, 1.24-1.53) were associated with screening. Living outside of a census-designated metropolitan area was negatively associated with screening (OR, 0.92; 95% CI, 0.87-0.97). CONCLUSIONS: In a private claims database representing 250 million claimants, 38.7% of eligible patients received United States Preventative Services Task Force-recommended AAA screening. Compliance was nearly one-half that of integrated health systems and was significantly lower for patients living outside of metropolitan areas. Efforts to improve early detection of AAA should include targeting non-metropolitan areas and modifying Medicare reimbursement and incentivization strategies to improve guideline adherence.

Female sex is independently associated with reduced inpatient mortality after endovascular repair of blunt thoracic aortic injury.

BACKGROUND: Female sex has been associated with decreased mortality after blunt trauma, but whether sex influences the outcomes of thoracic endovascular aortic repair (TEVAR) for traumatic blunt thoracic aortic injury (BTAI) is unknown. METHODS: In this retrospective study of a prospectively maintained database, the Vascular Quality Initiative registry was queried from 2013 to 2020 for patients undergoing TEVAR for BTAI. Univariate Student's t-tests and χ2 tests were performed, followed by multivariate logistic regression for variables associated with inpatient mortality. RESULTS: Of 806 eligible patients, 211 (26.2%) were female. Female patients were older (47.9 vs 41.8 years, P < .0001) and less likely to smoke (38.3% vs 48.2%, P = .044). Most patients presented with grade III BTAI (54.5% female, 53.6% male), followed by grade IV (19.0% female, 19.5% male). Mean Injury Severity Scores (30.9 + 20.3 female, 30.5 + 18.8 male) and regional Abbreviated Injury Score did not vary by sex. Postoperatively, female patients were less likely to die as inpatients (3.8% vs 7.9%, P = .042) and to be discharged home (41.4% vs 52.2%, P = .008). On multivariate logistic regression, female sex (odds ratio [OR]: 0.05, P = .002) was associated with reduced inpatient mortality. Advanced age (OR: 1.06, P < .001), postoperative transfusion (OR: 1.05, P = .043), increased Injury Severity Score (OR: 1.03, P = .039), postoperative stroke (OR: 9.09, P = .016), postoperative myocardial infarction (OR: 9.9, P = .017), and left subclavian coverage (OR: 2.7, P = .029) were associated with inpatient death. CONCLUSIONS: Female sex is associated with lower odds of inpatient mortality after TEVAR for BTAI, independent of age, injury severity, BTAI grade, and postoperative complications. Further study of the influence of sex on postdischarge outcomes is needed.

Validity of the Global Vascular Guidelines in Predicting Outcomes Based on First-Time Revascularization Strategy.

BACKGROUND: The Global Vascular Guidelines (GVG) recommend selecting an endovascular versus open-surgical approach to revascularization for chronic limb-threatening ischemia (CLTI), based on the Global Limb Anatomic Staging System (GLASS) and wound, ischemia, and foot infection (WIfI) classification systems. We assessed the utility of GVG-recommended strategies in predicting clinical outcomes. METHODS: We conducted a single-center, retrospective review of first-time lower-extremity revascularizations within a comprehensive limb-preservation program from 2010 to 2018. Procedures were stratified by (1) treatment concordance with GVG-recommended strategy (concordant versus nonconcordant groups), (2) GLASS stages I-III, and (3) endovascular versus open strategies. The primary outcome was 5-year freedom from major adverse limb events (FF-MALE), defined as freedom from reintervention or major amputation, and secondary outcomes included 5-year overall survival, freedom from major amputation, freedom from reintervention, and immediate technical failure (ITF) during initial revascularization. Kaplan-Meier (KM) survival analysis and multivariate analysis with Cox proportional hazard models were performed on the primary and secondary outcomes. RESULTS: Of 281 first-time revascularizations for CLTI, 251 (89.3%) were endovascular and 186 (66.2%) were in the concordant group, with a mean clinical follow-up of 3.02 ± 2.40 years. Within the concordant group alone, 167 (89.8%) of revascularizations were endovascular. The concordant group had a higher rate of chronic kidney disease (60.8% vs. 45.3%, P = 0.02), WIfI foot infection grade (0.81 ± 1.1 vs. 0.56 ± 0.80, P = 0.03), and WIfI stage (3.1 ± 0.79 vs. 2.8 ± 1.2, P < 0.01) compared to the non-concordant group. After both KM and multivariate analyses, there were no significant differences in 5-year FF-MALE or overall survival between concordant and non-concordant groups. There was higher freedom from major amputation in the non-concordant group on KM analysis (83.9% vs. 74.2%, P = 0.025), though this difference was non-significant on multivariate analysis (hazard ratio [HR]: 0.49, 95% confidence interval [CI]: 0.21-1.15, P = 0.10). The open group had lower MALE compared to the endovascular group (HR: 0.39, 95% CI: 0.17-0.91, P = 0.029) attributed to a lower reintervention rate in the open group (HR: 0.31, 95% CI: 0.11-0.87, P = 0.026). GLASS stage was not associated with significant differences in outcomes, but the severity of GLASS stage was associated with ITF (2.1% in stage 1, 6.4% in stage 2, and 11.7% in stage 3, P = 0.01). CONCLUSIONS: In this study, CLTI treatment outcomes did not differ significantly based on whether treatment was received in concordance with GVG-recommended strategy. There was no difference in overall survival between the endovascular and open groups, though there was a higher reintervention rate in the endovascular group. The GVG guidelines are an important resource to help guide the management of CLTI patients. However, in this study, both concordance with GVG guidelines and GLASS staging were found to be indeterminate in differentiating outcomes between complex CLTI patients treated primarily with an endovascular-first approach. The revascularization approach for a CLTI patient is a nuanced decision that must take into account patient anatomy and clinical status, as well as physician skill and experience and institutional resources.

Cardiac efficiency and Starling's Law of the Heart.

The formulation by Starling of The Law of the Heart states that 'the [mechanical] energy of contraction, however measured, is a function of the length of the muscle fibre'. Starling later also stated that 'the oxygen consumption of the isolated heart … is determined by its diastolic volume, and therefore by the initial length of its muscular fibres'. This phrasing has motivated us to extend Starling's Law of the Heart to include consideration of the efficiency of contraction. In this study, we assessed both mechanical efficiency and crossbridge efficiency by studying the heat output of isolated rat ventricular trabeculae performing force-length work-loops over ranges of preload and afterload. The combination of preload and afterload allowed us, using our modelling frameworks for the end-systolic zone and the heat-force zone, to simulate cases by recreating physiologically feasible loading conditions. We found that across all cases examined, both work output and change of enthalpy increased with initial muscle length; hence it can only be that the former increases more than the latter to yield increased mechanical efficiency. In contrast, crossbridge efficiency increased with initial muscle length in cases where the extent of muscle shortening varied greatly with preload. We conclude that the efficiency of cardiac contraction increases with increasing initial muscle length and preload. An implication of our conclusion is that the length-dependent activation mechanism underlying the cellular basis of Starling's Law of the Heart is an energetically favourable process that increases the efficiency of cardiac contraction. KEY POINTS: Ernest Starling in 1914 formulated the Law of the Heart to describe the mechanical property of cardiac muscle whereby force of contraction increases with muscle length. He subsequently, in 1927, showed that the oxygen consumption of the heart is also a function of the length of the muscle fibre, but left the field unclear as to whether cardiac efficiency follows the same dependence. A century later, the field has gained an improved understanding of the factors, including the distinct effects of preload and afterload, that affect cardiac efficiency. This understanding presents an opportunity for us to investigate the elusive length-dependence of cardiac efficiency. We found that, by simulating physiologically feasible loading conditions using a mechano-energetics framework, cardiac efficiency increased with initial muscle length. A broader physiological importance of our findings is that the underlying cellular basis of Starling's Law of the Heart is an energetically favourable process that yields increased efficiency.

Predictors of sac regression after fenestrated endovascular aneurysm repair.

OBJECTIVE: Aneurysm sac regression after standard endovascular aortic repair is associated with improved outcomes, but similar data are limited after fenestrated endovascular aortic repair (FEVAR). We sought to evaluate sac regression after FEVAR, and identify any predictors of this favorable outcome. METHODS: Patients undergoing elective FEVAR using the commercially available Zenith Fenestrated device (ZFEN; Cook Medical, Bloomington, IN) from 2012 to 2018 at a single institution were reviewed retrospectively. The maximal aortic diameter was compared between the preoperative scan and those obtained in follow-up. Patients with of 5 mm or more sac regression were included in the regression (REG) group, with all others in the nonregression (NONREG) group. Outcomes were compared between groups using univariate analysis, and logistic regression analysis was performed to identify any predictive factors for sac regression. RESULTS: We included 132 patients undergoing FEVAR in the analysis. At a mean follow-up of 33.1 months, 65 patients (49.2%) had sac regression of 5 mm or more and comprised the REG group (n = 65 [49.2%]). The REG group had smaller diameter devices, and were less likely to have had concomitant chimney grafts placed (P < .05). The NONREG group had a higher incidence of type II endoleak (35.8% vs 12.3%; P = .002). Sac regression was associated with a significant mortality benefit on Kaplan-Meier analysis (log rank P = .02). Multivariate analysis identified adjunctive parallel grafting (odds ratio [OR], 0.01; 95% confidence interval [CI], 0.03-0.36; P < .01), persistent type II endoleak (OR, 0.13; 95% CI, 0.02-0.74; P < .01), and a greater number of target vessels (OR, 0.25; 95% CI, 0.10-0.62; P = .002) as independent predictors of failure to regress. CONCLUSIONS: Sac regression after FEVAR occurred in nearly one-half of patients, but seems to be less common in patients with persistent type II endoleaks and those undergoing concomitant parallel grafting. Sac regression was associated with a significant survival advantage, and can be used as a clinical marker for success after FEVAR.

Reintervention does not affect long-term survival after fenestrated endovascular aneurysm repair.

OBJECTIVE: Fenestrated endovascular aneurysm repair (FEVAR) is increasingly used in the treatment of juxtarenal aortic aneurysms and short-neck infrarenal aneurysms. Reinterventions (REIs) occur frequently, contributing to patient morbidity and resource utilization. We sought to determine whether REI affects long-term survival after FEVAR. METHODS: A single-institution retrospective review of all Cook Zenith fenestrated (ZFEN; Cook Medical, Inc, Bloomington, IN) repairs was performed. Patients with ≥6 months of follow-up and without adjunctive branch modifications were included. REI was defined as any aneurysm, device, target branch, or access-related intervention after the index procedure. REIs were categorized as early (<30 days) or late (≥30 days), by indication (ie, branch, endoleak, limb related, access related, other), and by target branch or device components. Patients were stratified into REI vs no REI groups and branch REI vs non-branch REI groups. RESULTS: Of 219 consecutive ZFEN repairs from 2012 to 2021, 158 patients met the inclusion criteria. Of these 158 patients, 41 (26%) required a total of 51 REIs (10 early and 41 late) during a mean follow-up of 33.9 months. The most common indication for REI was branch-related (31 of 51; 61%), with the renal arteries the most frequently affected (26 of 51; 51%). The only differences found in baseline, aneurysm, and device characteristics were a higher mean Society for Vascular Surgery comorbidity score (9.6 vs 7.9; P = .04) and larger suprarenal neck angle (23.3° vs 17.1°; P = .04) in the no REI group. In contrast, the REI group had a larger mean proximal seal zone diameter (26.3 mm vs 25.1 mm; P = .03) and device diameter (31.9 mm vs 30.0 mm; P = .002) compared with the no REI group. Technical success and operative characteristics were similar between the groups, except for a longer mean fluoroscopy time (74.9 minutes vs 60.8 minutes; P = .01) and longer median length of stay (2 vs 2 days; P = .006) for the REI group. Although the rate of early (<30 days) major adverse events was greater for the REI group (24.4% vs 6.0%; P = .001), the difference in 30-day mortality was not statistically significant (4.9% vs 0.9%; P = .10). On Kaplan-Meier analysis, freedom from REI at 1 and 5 years was 85.7% and 62.6%, respectively, for the overall cohort. No difference was found in the estimated 5-year survival between the REI and no REI groups (62.8% vs 63.5%; log-rank, P = .87) and branch REI and non-branch REI groups (71.8% vs 49.9%; log-rank, P = .16). On multivariate analysis, REI was not an independent predictor for mortality. However, age, Society for Vascular Surgery comorbidity score, and preoperative maximum aneurysm diameter each increased the hazard of death (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.02-1.12 [P = .007]; HR, 1.10; 95% CI, 1.01-1.18 [P = .02]; HR, 1.05; 95% CI, 1.02-1.08 [P = .003], respectively). CONCLUSIONS: After ZFEN, 41 patients (26%) had required a total of 51 REIs, with most occurring ≥30 days after the index procedure, and 61% were branch related, with no influence on 5-year survival. Age, comorbidity, and baseline aneurysm diameter independently predicted mortality. The use of FEVAR mandates lifelong surveillance and protocols to maintain branch patency. Despite their relative frequency, REIs did not influence 5-year postprocedural survival.

Hierarchical semantic composition of biosimulation models using bond graphs.

Simulating complex biological and physiological systems and predicting their behaviours under different conditions remains challenging. Breaking systems into smaller and more manageable modules can address this challenge, assisting both model development and simulation. Nevertheless, existing computational models in biology and physiology are often not modular and therefore difficult to assemble into larger models. Even when this is possible, the resulting model may not be useful due to inconsistencies either with the laws of physics or the physiological behaviour of the system. Here, we propose a general methodology for composing models, combining the energy-based bond graph approach with semantics-based annotations. This approach improves model composition and ensures that a composite model is physically plausible. As an example, we demonstrate this approach to automated model composition using a model of human arterial circulation. The major benefit is that modellers can spend more time on understanding the behaviour of complex biological and physiological systems and less time wrangling with model composition.

Fenestrated Aortic Aneurysm Repair in Patients Treated Inside Versus Outside of Instructions for Use.

OBJECTIVES: The aim of this study was to compare outcomes of patients treated with the Cook Zenith Fenestrated (ZFEN) device for juxtarenal aortic aneurysms inside versus outside the IFU. METHODS: We retrospectively reviewed our institutional ZFEN database for cases performed between 2012 and 2018, with analysis performed in 2020 in order to report midterm outcomes. The cohort was stratified based on treatment inside (IFU group) and outside (non-IFU group) the IFU for criteria involving the proximal neck: neck length 4 to 14 mm, neck diameter 19 to 31 mm, and neck angulation ≤45°. Patients with thoracoabdominal aneurysms or concurrent chimney grafting were excluded. The primary outcomes in question were mortality, type 1a endoleak, and reintervention. Univariate and multivariate analyses were performed to determine associations between adherence to IFU criteria and outcomes. RESULTS: We identified 100 consecutive patients (19% female, mean age 73.6 years) for inclusion in this analysis. Mean follow-up was 21.6 months. Fifty-four patients (54%) were treated outside the IFU because of inadequate neck length (n=48), enlarged neck diameter (n=10), and/or excessive angulation (n=16). Eighteen patients were outside IFU for two criteria, and one patient was outside IFU for all three. Non-IFU patients were exposed to higher radiation doses (3652 vs 5445 mGy, p=0.008) and contrast volume (76 vs 95 mL, p=0.004). No difference was noted between IFU and non-IFU groups for 30-day mortality (0% vs 3.7%, p=0.18), or type 1a endoleak (0% vs 1.9%, p=0.41). Reintervention was also similar between cohorts (13% vs 27.8%, p=0.13). Being outside IFU for neck diameter or length was each borderline significant for higher reintervention on univariate analysis (p=0.05), but this was not significant on multivariate Cox proportional hazard modeling (HR 1.82 [0.53-6.25]; 2.03 [0.68-7.89]), respectively. No individual IFU deviations were associated with the primary outcomes on multivariate analysis, nor being outside IFU for multiple criteria. CONCLUSIONS: Patients with juxtarenal aortic aneurysms may be treated with the ZFEN device with moderate deviations from the IFU. While no differences were seen in mortality or proximal endoleak, larger studies are needed to examine the potential association between IFU nonadherence and reinterventions and close follow-up is warranted for all patients undergoing such repair.

Fenestrated Endovascular Repair With Large Device Diameters (34-36 mm) is Associated With Type 1 and 3 Endoleak and Reintervention.

BACKGROUND: Patients with abdominal aortic aneurysms undergoing EVAR with larger device diameters (34-36 mm) have worse outcomes due to proximal fixation failure and need for reintervention. We examine outcomes relating to standard fenestrated repair (FEVAR) with larger device diameters, and investigate whether a similar relationship exists. METHODS: Retrospective review of a prospectively maintained, single institution database of patients treated with the Cook ZFEN device between 2012-2017. Outcomes were stratified by device diameter into normal-diameter (ND,≤ 32 mm) and large-diameter (LD,34-36 mm). Primary endpoints were need for reintervention and composite type I/III endoleak. RESULTS: One-hundred consecutive patients treated were identified for inclusion. Overall mean age was 73.6 years and mean aortic diameter was 59.1 mm. Mean follow-up was 22 months. A total of 26 (26%) patients were treated with LD devices. Number of target vessels per patient was 2.8 in both groups. Infrarenal neck length and diameter were significantly different in the LD and ND patients, respectively (2.6 mm vs. 4.7 mm (P < 0.01) and 30.1 mm vs. 23.4 mm (P < 0.01)). Percent graft oversizing was lower in the LD cohort (19% vs. 24%; P = 0.006). No difference was seen in overall mortality at 30-days (0% vs. 2%; P = 0.4) or at latest follow up (6% vs. 14%; P = 0.6). Reinterventions were not significantly different at 30 days, but were significantly higher over the follow-up period in the LD cohort (46.2 vs. 17.6%; P = 0.002). LD diameter was associated with reintervention on univariate (HR 1.19, 95% CI 1.04-1.37), but not multivariate analysis. The composite endpoint of type I/III endoleak was higher in the LD cohort (15.4% vs. 2.7%; P = 0.004). CONCLUSIONS: FEVAR requiring 34- or 36-mm device diameters is associated with an increased risk of composite type I/III endoleak and reintervention. Patients undergoing fenestrated repair requiring LD devices should be closely monitored, with consideration for proximal or open repair.

Anatomic Factors Contributing to External Iliac Artery Endofibrosis in High-Performance Athletes.

BACKGROUND: External iliac artery endofibrosis (EIAE) classically presents in cyclists with intimal thickening of the affected arteries. We investigated possible anatomical predisposing factors including psoas muscle hypertrophy, arterial tortuosity, inguinal ligament compression, and arterial kinking via a case-control comparison of symptomatic and contralateral limbs. METHODS: All patients with unilateral EIAE treated surgically at our institution were reviewed. Each patient's symptomatic side was compared with their contralateral side using paired t-tests. Psoas hypertrophy was quantified by the transverse cross-sectional area (CSA) at L4, L5, and S1 vertebral levels, and inguinal ligament compression was measured as the anterior-posterior distance between the inguinal ligament and underlying bone. Tortuosity index for diseased segments and arterial kinking were measured on TeraRecon. RESULTS: Of 33 patients operated on for EIAE from 2004 to 2021, 27 with available imaging presented with unilateral disease, more commonly left-sided (63%). Most (96%) had external iliac involvement and 26% had ≥2 segments affected: 19% common iliac artery, 15% common femoral artery. The symptomatic limb had greater mean L5 psoas CSA (1,450 mm2 vs. 1,396 mm2, mean difference 54 mm2, P = 0.039). There were no significant differences in L4 or S1 psoas hypertrophy, tortuosity, inguinal ligament compression, or arterial kinking. 63% underwent patch angioplasty, and 85% underwent additional inguinal ligament release. 84% reported postoperative satisfaction, which was associated with a greater difference in psoas hypertrophy at L4 (P = 0.022). CONCLUSIONS: Psoas muscle hypertrophy is most pronounced at L5 and is associated with symptomatic EIAE. Preferential hypertrophy of the affected side correlates with improved outcomes, suggesting psoas muscle hypertrophy as a marker of disease severity.

Large Fenestrations Versus Scallops for the Superior Mesenteric Artery during Fenestrated Endovascular Aneurysm Repair: Does it Matter?

BACKGROUND: Fenestrated endovascular aneurysm repair is an established customized treatment for aortic aneurysms with 3 current commercially available configurations for the superior mesenteric artery (SMA)-a single-wide scallop, large fenestration, or small fenestration, with the scallop or large fenestration most utilized. Outcomes comparing SMA single-wide scallops to large fenestrations with the Zenith fenestrated (ZFEN) device are scarce. As large fenestrations have the benefit of extending the proximal seal zone compared to scalloped configurations, we sought to determine the differences in seal zone and sac regression outcomes between the 2 SMA configurations. METHODS: We retrospectively reviewed our prospectively maintained complex endovascular aneurysm repair database and included all patients treated with the Cook ZFEN device with an SMA scallop or large fenestration configuration at its most proximal build. All first postoperative computed tomography scans (1-30 days) were analyzed on TeraRecon to determine precise proximal seal zone lengths, and standard follow-up anatomic and clinical metrics were tabulated. RESULTS: A total of 234 consecutive ZFEN patients from 2012 to 2021 were reviewed, and 137 had either a scallop or a large fenestration for the SMA as the proximal-most configuration (72 scallops and 65 large fenestrations) with imaging available for analysis. The mean follow-up was 35 months. The mean proximal seal zone length was 19.5 ± 7.9 mm for scallop versus 41.7 ± 14.4 mm for large fenestration groups (P < 0.001). There was no difference in sac regression between the scallop and large fenestration at 1 year (10.1 ± 10.9 mm vs. 11.0 ± 12.1, P = 0.63). Overall, 30-day mortality (1.3% vs. 2.5%, P = 0.51) and all-cause 3-year mortality (72.5% vs. 81.7%, P = 0.77) were not significantly different. Reinterventions within 30 days were primarily secondary to renal artery branch occlusions, with only 1 patient in the scallop group requiring reintervention for an SMA branch occlusion. CONCLUSIONS: Despite attaining longer proximal seal lengths, large SMA fenestrations were not associated with a difference in sac regression compared to scalloped SMA configurations at a one-year follow-up. There were no significant differences in reinterventions or overall long-term survival between the 2 SMA strategies.

Quantification of suprarenal aortic neck dilation after fenestrated endovascular aneurysm repair.

OBJECTIVE: Suprarenal aortic neck dilation (AND) after fenestrated endovascular aneurysm repair (FEVAR) with commercially available devices has not yet been well characterized. The aim of this study was to measure diameter changes in the supravisceral aorta after FEVAR. METHODS: This is a single-center retrospective review involving patients with juxtarenal aneurysms treated with Cook ZFEN devices (Cook Medical, Bloomington, Ind). Patients with at least 1 year of cross-sectional radiologic follow-up were included. AND was defined as ≥3 mm at any measured location. Aortic diameter, defined as the average outer to outer diameter on three-dimensional centerline imaging, was measured at seven locations along the length of the ZFEN device from the proximal fixation struts to the bottom of the second seal stent. The first postoperative CT scan (≤1 month) served as a baseline from which subsequent measurements at annual intervals were compared. RESULTS: A total of 43 patients who underwent FEVAR from 2012 to 2018 met inclusion criteria, with a total of 119 target vessels (83 renal stents, 41 superior mesenteric artery scallops or large fenestrations). Mean follow-up time was 30.3 months. Any AND was found to occur in 32 (74.4%) patients. Aortic diameter dilation at latest follow-up was found to occur at all measured locations from the top of the fixation struts (1.9 ± 2.4 mm; P < .0001) to the middle of the second seal stent (1.3 ± 3.8 mm; P < .01). Diameter growth was most pronounced in the middle of the first seal stent, with mean AND of 3.6 ± 3.2 mm. At this location, the aorta experienced nearly linear annual growth of 0.99 mm (95% confidence interval, 0.7-1.28 mm) per year. Increasing device oversizing relative to the native visceral aorta was the strongest predictor of postoperative neck diameter growth (1.34 mm per 10% increase in oversizing; P = .02), whereas increasing proximal seal length was protective of growth (-1.82 mm per 10-mm increase in seal length; P = .016). Proximal seal lengths ≥3 cm were associated with less neck dilation compared with <3 cm (2.6 mm vs 4.9 mm; P = .022). Type IA endoleak in this cohort was rare (n = 1) and not associated with AND (P = .256). CONCLUSIONS: Dilation of the suprarenal aorta is a common finding in midterm follow-up after FEVAR and not associated with proximal endoleak. Aggressive device oversizing is predictive of dilation, whereas longer seal lengths are associated with less dilation along the suprarenal seal zone. These results support the continued use of FEVAR for juxtarenal aneurysms, particularly in patients in whom ≥3 cm of healthy seal length can be obtained.

Respiratory-induced changes in renovisceral branch vessel morphology after fenestrated thoracoabdominal aneurysm repair with the BeGraft balloon-expandable covered stent.

OBJECTIVE: We evaluated the respiratory-induced changes in branch vessel geometry after thoracoabdominal fenestrated endovascular aneurysm repair (fEVAR) with the Bentley BeGraft graft (Innomed GmbH, Hechingen, Germany) as the covered bridging stent. METHODS: Patients treated with fEVAR for thoracoabdominal aortic aneurysms with a custom-made Zenith fenestrated endograft (Cook Medical Europe Ltd, Limerick, Ireland) and Bentley BeGraft peripheral stents were prospectively recruited. Using SimVascular software (Open-Source Medical Software Corp, San Diego, CA), the pre- and postoperative aortic and branch contours were segmented from computed tomography angiograms performed during inspiratory and expiratory breath-holds. The centerlines were extracted from the lumen contours, from which the branch take-off angles, distal stent angles, and peak branch curvature changes were computed. Paired, two-tailed t tests were performed to compare the pre- and postoperative deformations. RESULTS: Renovisceral vessel geometry was evaluated in 12 patients undergoing fEVAR with a total of 46 target vessels (10 celiac arteries, 12 superior mesenteric arteries [SMAs], 24 renal arteries). Implantation of BeGraft bridging stents was associated with a significant reduction in respiration-induced changes in vessel branch angulation (Δ5.3° ± 3.9° vs Δ12.0° ± 8.3° [postoperative vs preoperative]; P = .001) and mean curvature (0.72 ± 0.22 cm-1 vs 0.53 ± 0.18 cm-1) in the renal arteries, without significant changes in the celiac arteries or SMAs. No significant difference was found in end-stent angle motion in the renal arteries (P = .77), celiac arteries (P = .34), or SMAs (P = .55). The maximum local vessel curvature change decreased after fEVAR in the SMAs (Δ0.28 cm-1 vs Δ0.47 cm-1; P = .04) but was unchanged in the celiac (P = .61) and renal (P = .51) arteries. CONCLUSIONS: Implantation of the BeGraft as a bridging stent in fEVAR was associated with decreased respiratory-induced deformation in the renal branch take-off angulation and mean renal artery curvature, with reduced maximum curvature bending in the SMA compared with the preoperative anatomy. However, the BeGraft allowed for celiac and renal artery bending similar to that in the native preoperative state. These findings suggest that the use of BeGraft peripheral stents with fEVAR will closely mimic the native arterial branch geometry and vessel conformability caused by relatively aggressive respiratory motion.

Long-term chimney/snorkel endovascular aortic aneurysm repair experience for complex abdominal aortic pathologies within the PERICLES registry.

OBJECTIVE: The early and short-term efficacy of the snorkel/chimney technique for endovascular aortic aneurysm repair (ch-EVAR) have been previously reported. However, long-term ch-EVAR performance, vessel patency, and patient survival remain unknown. Our study evaluated the late outcomes to identify possible predictors of failure within the PERICLES (performance of the chimney technique for the treatment of complex aortic pathologies) registry. METHODS: Clinical and radiographic data from patients who had undergone ch-EVAR from 2008 to 2014 in the PERICLES registry were updated with an extension of the follow-up. Regression models were used to evaluate the relevant anatomic and operative characteristics as factors influencing the late results. We focused on patients with ≥30 months of follow-up (mean, 46.6 months; range, 30-120 months). RESULTS: A total of 517 patients from the initial PERICLES registry were included in the present analysis, from which the mean follow-up was updated from 17.1 months to 28.2 months (range, 1-120 months). All-cause mortality at the latest follow-up was 25.5% (n = 132), with an estimated patient survival of 87.6%, 74.4%, and 66.1% at 1, 3, and 5 years, respectively. A subgroup of 244 patients with 387 chimney grafts placed (335 renal arteries, 42 superior mesenteric arteries, 10 celiac arteries) and follow-up for ≥30 months was used to analyze specific anatomic and device predictors of adverse events. In the subgroup, the technical success was 88.9%, and the primary patency was 94%, 92.8%, 92%, and 90.5% at 2.5, 3, 4, and 5 years, respectively. The mean aneurysm sac regression was 7.8 ± 11.4 mm (P < .0001). Chimney graft occlusion had occurred in 24 target vessels (6.2%). Late open conversion was required in 5 patients for endograft infection in 2, persistent type Ia endoleak in 2, and endotension in 1 patient. The absence of an infrarenal neck (odds ratio, 2.86; 95% confidence interval, 1.32-6.19; P = .007) was significantly associated with long-term device-related complications. A sealing zone diameter >30 mm was significantly associated with persistent or late type Ia endoleak (odds ratio, 4.86; 95% confidence interval, 1.42-16.59; P = .012). CONCLUSIONS: The present analysis of the PERICLES registry has provided the missing long-term experience for the ch-EVAR technique, showing favorable results with more than one half of the patients surviving for >5 years and a chimney graft branch vessel patency of 92%. The absence of an infrarenal neck and treatment with a sealing zone diameter >30 mm were the main anatomic long-term limits of the technique, requiring adequate preoperative planning and determination of the appropriate indication.

Evaluation of Acute Postoperative Pain Management During an Injectable Opioid Shortage.

BACKGROUND: Drug product shortages, including injectable opioids, are common and have the potential to adversely affect patient care. OBJECTIVE: To evaluate the impact of an injectable opioid shortage for hospitalized adult patients in the acute postoperative setting. METHODS: A single-center, retrospective cohort study of noncritically ill hospitalized, postoperative patients requiring opioids for acute pain management was conducted. Patient cohorts were compared preshortage and postshortage for proportion of total intravenous (IV) opioids used, proportions of specific pain medications used, subjective pain scores, 30-day mortality, respiratory depression, need for opioid reversal, hospital length of stay, and opioid equivalent doses. RESULTS: A total of 275 patients were included, 130 patients in the preshortage cohort and 145 in the postshortage cohort. The proportion of total IV opioid doses was lower in the postshortage cohort versus the preshortage cohort (16.6% vs 20.5%; P < 0.01). Specific medications used were significantly different between the cohorts. The proportion of severe pain scores was lower in the postshortage cohort versus the preshortage cohort (55.6% vs 58.5%; P = 0.04). No significant differences were seen in the overall proportion of nonopioid analgesic use, 30-day mortality, respiratory depression, need for emergent opioid reversal, hospital length of stay, or opioid equivalent doses between cohorts. CONCLUSION AND RELEVANCE: In hospitalized, postoperative adults, an injectable opioid shortage was associated with significant decreases in IV opioid use and severe pain scores but no significant differences in nonopioid analgesic use, safety outcomes, or opioid equivalent doses. These results may assist clinicians in developing strategies for injectable opioid shortages and generating hypotheses for future studies.

Unique Complications and Failure Modes of Iliac Branch Devices.

OBJECTIVES: Iliac branch devices (IBDs) are modular, bifurcated endografts designed to preserve hypogastric flow during endovascular aortoiliac aneurysm repair. We report our single center outcomes, and describe the unique complications of these devices: inability to cannulate the hypogastric artery (technical failure), occlusion of the internal branch, and type III endoleak from separation of components between the main body and IBD. METHODS: A prospectively maintained institutional database of patients undergoing IBD implantation between 2014 and 2019 was reviewed. Technical and clinical outcomes were evaluated. We then identified patients having one of the IBD-specific complications and patient, anatomic, and procedural data were analyzed to identify factors associated with these failures. RESULTS: Sixty-four IBDs were placed in 59 patients during the study period. Mean age was 71.2 ± 8.6, and 92% were male. A 74.6% of patients had a current or prior abdominal aortic aneurysm, and 9.4% had a hypogastric aneurysm. Technical success was achieved in 60/64 cases (93.8%); prior endovascular aortic repair was associated with technical failure (P = 0.04). There were 5 instances of component separation between the main body and the IBD: 3 occurred intraoperatively and were repaired with additional bridging components, and 2 occurred on late follow-up and required reintervention. Increased tortuosity index of both aortoiliac (1.7 ± 0.4 vs. 1.3 ± 02, P = 0.04) and iliac-specific (3.9 ± 2.4 vs. 1.9 ± 0.9, P = 0.03) segments were significantly associated with component separation, as was the use of larger internal iliac components (13.9 ± 2.4 vs. 11.1 ± 2.3 mm, P = 0.04). Internal branch occlusions occurred in 4 patients (6.7%). Two were successfully reopened with endovascular procedures, with two being asymptomatic. No specific factors were found to be predictive of branch occlusion. CONCLUSIONS: IBD-specific complications occur rarely. History of prior endovascular aortic repair is associated with technical failure, while increased aortic and iliac tortuosity are predictive of component separation and type III endoleak. Severe tortuosity should be carefully considered when planning for IBD.

Renal Stent Complications and Impact on Renal Function after Standard Fenestrated Endovascular Aneurysm Repair.

BACKGROUND: To report renal outcomes including long-term patency, secondary interventions, and related renal function after fenestrated endovascular aortic repair (fEVAR). METHODS: Single-center retrospective review of patients undergoing fEVAR between 2012 and 2018 using the Cook ZFEN device. Renal stent complications, defined as any stenosis, occlusion, kink, renal stent-related endoleak, and reinterventions were tabulated. Estimated glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease formula. RESULTS: During the study period, 114 patients underwent elective fEVAR. Of 329 total target vessels, 193 renal arteries were stented (133 Atrium iCAST, 60 Gore VBX). Technical success was achieved in 97.4%, and the mean follow-up was 23.3 months. Seventeen renal complications occurred in 14 patients (12.3%), including 4 occlusions, 9 stenosis, 3 dislocations, and 1 type III endoleak. All stent complications underwent endovascular reintervention with a median hospital stay of 1 day (0-10) and a technical success of 94.2%. One patient suffered renal hemorrhage that warranted embolization. Patients with occlusion were treated the day of diagnosis, and mean time from diagnosis to intervention for stenosis was 21.5 days. Estimated primary patency was 92.1 % and 81.5% at 24 and 48 months, respectively. On multivariate analysis, larger native renal artery diameter was the only independent protective factor against patency loss (HR 0.23 (0.09-0.59)). Secondary patency at latest follow-up was 99.4%. Mean eGFR was not significantly different at latest follow-up between patients with renal complications versus those without (43.75 vs. 55.58 mL/min/1.73 m2, P = 0.09). Comparing patients with and without renal stent complications, 81.4% and 72.7% of patients had stable or improved renal disease by chronic kidney disease staging compared with baseline (P = 0.51). CONCLUSIONS: fEVAR is a durable option for the treatment of juxtarenal aortic aneurysms and is associated with excellent secondary patency. Renal stent complications have no significant impact on renal function, but smaller native renal arteries are at higher risk of stent-graft complications.

Thoracic Aortic Dilation after Endovascular Repair of Blunt Traumatic Aortic Injury.

BACKGROUND: Thoracic endovascular aneurysm repair (TEVAR) has become the current standard of care for emergent treatment of traumatic blunt thoracic aortic injuries (BTAI). Although aortic dilation (AD) of the infrarenal neck after EVAR for aortic aneurysms has been studied, changes in aortic diameter after TEVAR for BTAI is not well understood. This study aims to characterize changes in thoracic aortic diameter after stent-graft placement in the setting of nonaneurysmal traumatic aortic injury. METHODS: A single-center, retrospective review was performed involving patients presenting with BTAI treated with TEVAR. Only patients with at least 12 months follow-up were included. Aortic diameter, defined as the outer-to-outer diameter on 3D center-line imaging, was measured at six locations along the proximal and mid thoracic aorta. The first postoperative CT (≤1 month) served as a baseline from which interval measurements were compared. RESULTS: Twenty patients with BTAI treated from 2011 to 2017 had adequate imaging available for review and were included in this study cohort. Median follow-up time was 46.8 (12-80, range) months. At the latest follow-up, AD occurred at all measured locations within the endograft, starting from the proximal graft edge (0.62 ± 0.69 mm, P = 0.027) to the distal graft edge (1.21 ± 1.28 mm, P = 0.003). AD was most pronounced in the distal graft segment 2 cm proximal to the distal graft edge, with a mean AD of 1.32 ± 1.59 mm (+5.3%, P < 0.001). At this location, AD was found to increase in a linear manner with an estimated rate of 0.67 ± 0.20 mm/year (P = 0.006). The native aorta proximal and distal to the endograft was not found to significantly dilate during follow-up (P = 0.280-0.897). Seventy percent of the patients were found to have AD >5%. The amount of AD was not found to be associated with either graft oversizing (P = 0.151) or age (P = 0.340). There were no cases of graft migration, erosion, or endoleak. CONCLUSIONS: AD is a common benign finding after TEVAR for BTAI. AD is most pronounced at the near the distal end of the stent graft. In late-term follow-up, there are no known associated complications related to AD.

Paclitaxel exposure and long-term mortality of patients treated with the Zilver PTX drug-eluting stent.

OBJECTIVES: Paclitaxel-eluting stents have demonstrated improved patency over balloon angioplasty and bare metal stenting for endovascular interventions in the femoral-popliteal segment. Recently, concerns have arisen regarding the safety of paclitaxel use and its association with mortality. This study aims to examine real-world, long-term mortality, and patency of patients treated with the Zilver PTX drug-eluting stent. METHODS: Patients treated with the PTX stent after FDA approval between 2013 and 2015 were identified from an institutional database. Demographic, procedural, and device information was collected and initial- and lifetime-exposure dose of paclitaxel was calculated. The primary outcome was all-cause mortality and its association with paclitaxel exposure. Long-term patency was also evaluated. RESULTS: Seventy-nine procedures involving PTX placement were performed on 64 individual patients during the study period, with 15 (23.4%) having bilateral procedures. Average age was 70 years, and 71.9% were male. Forty-five patients (70.3%) were claudicants, and 19 (29.7%) had chronic, limb-threatening ischemia. An average of 2.3 PTX stents, totaling 203 mm in length, were placed per procedure. Paclitaxel exposure was 1.87 mg/procedure initially (range 0.38-4.03 mg), and average lifetime exposure was 4.65 mg/patient (range 0.38-27.91 mg). Average follow-up was 59.6 months. Kaplan-Meier estimated survival was 96.9%, 81.2% and 71.7% at one , three, and five years. On multivariate analysis, no specific factors were associated with overall morality including initial paclitaxel dose (HR 0.99, 95% CI 0.99-1.00) and lifetime paclitaxel exposure (HR 0.98, 95% CI 0.89-1.08). Kaplan-Meier primary patency was 76.2%, 60.1%, and 29.3% at one, two, and five years, respectively. Secondary patency was 92.2%, 85.4%, and 75.2% at the same intervals. CONCLUSIONS: At a mean follow-up of five years, exposure to higher doses of paclitaxel from Zilver PTX does not appear to be associated with increased mortality compared to lower doses in real-world patients. Long-term patency rates confirm the efficacy of Zilver PTX, and further investigation may be warranted before abandoning paclitaxel use altogether.