Instructions For Use Criteria Research Articles

A Retrospective Analysis of Late Open Conversions Following Failed Endovascular Aneurysm Repair.

The incidence of late open surgical conversions (OSCs) has recently increased. Vascular surgeons face additional technical challenges in late conversion surgery of failed endovascular aneurysm repair (EVAR) due to the presence of a previously deployed endograft. Based on our institutional experience, this study aimed to delineate methods to improve late open conversion outcomes, proposing solutions for technical challenges. All preoperative OSC data on failed EVARs operated in our Cardiovascular Surgery Clinic between January 2017 and January 2024 were evaluated retrospectively. Study endpoints included early (30-day or in-hospital) and late follow-up outcomes. Early outcomes included perioperative mortality and morbidities, intensive care unit (ICU) period, and length of hospital stay (LOS). The main outcome of interest during follow-up was overall survival. Sixteen patients in our hospital, comprising eight elective and eight emergency procedures, underwent OSCs following EVAR. The difference between the 30-day mortality rates for the elective and urgent late conversions was significant (p < 0.001). Of these patients, 15 were male, with a mean age of 70.8 years (range: 62-80). Preoperative cardiac shock status and low hematocrit level (<20%) were independent mortality factors (p < 0.001). The ICU period was 8.7 ± 5.3 days (2-20 days) on average, and LOS was 17.3 ± 8.4 (6-29 days) days on average. The mean time to open surgical conversion in this cohort was 44.4 ± 16.8 months. The 5-year overall survival rate was 43.75%. The incidence of open surgical conversion is notably growing. Emergent open surgical conversions exhibit poorer mortality outcomes compared to elective procedures. Further data are essential to evaluate the ramifications of expanding the use of EVAR beyond the instructions for use (IFU) guidelines. The procedures involving patients who challenge the IFU criteria should be conducted at experienced centers and require close monitoring. Open surgical repair (OSR) as the initial treatment opportunity could be an alternative strategy for improving outcomes in this patient cohort.

Endovascular repair in type A aortic dissection: Anatomic candidacy for currently manufactured stentgrafts and conceptual valve-carrying devices for an Endo-Bentall procedure.

Endovascular treatment has been suggested as alternative for open surgery as treatment for type A aortic dissection, but current devices have severe anatomic limitations. This study assesses computed-tomography-based anatomic suitability of currently manufactured stent grafts as well as two embodiments of valve-carrying devices. In a retrospective single-center cohort of 200 consecutive ascending/arch operations between 2009 and 2018, 112 type A aortic dissection patients were identified and evaluated for endovascular candidacy based on locations of entries, landing zone diameters/lengths and supra-aortic vessel origins according to the anatomical instructions for use criteria of 6 commercially available, (tubular, branched or fenestrated) stentgrafts. Two suggested valve-carrying devices with inner branches or fenestrations for the coronary arteries and branches for the supra-aortic vessels were also evaluated. The anatomic feasibility for commercial stentgrafts ranged from 4% to 21%. The main limitations was proximal landing zone diameter (considering oversizing <15%) and length due to dilatation and an entry too close to the sinotubular junction. For the valve-carrying conduits, anatomical feasibility was between 31% and 80%. with the main limiting factors the diameter of the aortic annulus and its distance to the coronary arteries. Anatomic applicability of currently manufactured stentgrafts for the treatment of type A aortic dissection is mainly limited by the absence of a suitable proximal landing zone in the ascending aorta and might substantially be improved by anchoring in the aortic annulus using a valve-carrying device which employs either fenestrations or branches for the coronary arteries.

Endovascular Repair of Abdominal Aortic Aneurysms is a Valid Alternative to Open Repair also in Patients Treated Outside of Instructions for Use Criteria

PurposeIt remains unclear whether endovascular aneurysm repair, in the long term, is less effective than open surgery due to need for reinterventions and close monitoring. We aimed to evaluate this matter in a real-life cohort.MethodsWe collected consecutive patients treated with EVAR or OSR between January 2005 and December 2013. Primary outcomes were 30-day, 90-day and long-term all-cause mortality. Secondary outcomes were 30-day reintervention rate and reintervention-free survival. We evaluated also a subpopulation who did not adhere to IFU.ResultsThe inclusion criteria were met by 416 patients. 258 (62%) received EVAR, while 158 (38%) underwent OSR. The 30- or 90-day mortality was similar between groups (p = 0.272 and p = 0.346), as ARM (p = 0.652). The 30-day reintervention rate was higher in the OSR group (p < 0.001), but during follow-up, it was significantly higher in the EVAR group (log-rank: 0.026).There were 114 (44.2%) non-IFU patients in the EVAR group, and we compared them with OSR group. There was no significant difference in all-cause mortality at 30 or 90 days, nor in the long term (p = 1; p = 1 and p = 0.062). ARM was not affected by the procedure technique (p = 0.136). The short-term reintervention rate was higher in the OSR group (p = 0.003), while in the long-term EVAR, patients experienced more reinterventions (log-rank = 0.0.43).ConclusionNo significant difference in survival was found between EVAR and OSR, independent of adherence to IFU. EVAR may be considered for surgical candidates.

Long-term outcomes of endovascular aneurysm repair according to instructions for use adherence status

ObjectiveEndovascular aneurysm repair (EVAR) has become the standard treatment for abdominal aortic aneurysms (AAAs). Endovascular device manufacturers have defined specific anatomic criteria for the aneurysm characteristics that should be observed as instructions for use (IFU) for specific grafts. In clinical practice, the prevalence of performing EVAR outside the IFU has been high. In the present study, we aimed to determine the effects of nonadherence to the IFU on the outcomes. MethodsPatients who had undergone EVAR for an infrarenal AAA between 2005 and 2013 were included. IFU nonadherence was defined as any violation of device-specific IFU criteria and was compared with IFU adherence. The primary outcomes were all-cause mortality, aneurysm-related mortality, AAA rupture, graft-related adverse events (GRAEs), including limb-related adverse events, and type Ia endoleaks. A second aim was to study whether the prevalence of EVAR performed outside the IFU has increased over time. ResultsA total of 258 patients were included, 144 (55.8%) of whom had been treated according to the IFU and 114 (44.2%) outside the IFU. In the IFU nonadherence group, all-cause mortality (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.02-1.89; P = .037) and aneurysm-related mortality (HR, 5.1; 95% CI, 1.4-18.6; P = .015), and the incidence of AAA rupture (HR, 5.4; 95% CI, 1.1-26.6; P = .036) and GRAEs (HR, 1.7; 95% CI, 1.1-2.8; P = .025). No significant association was found between the incidence of type Ia endoleaks and neck-related IFU or limb-related adverse events and iliac-related IFU. However, neck length was a risk factor for type Ia endoleaks (HR, 18.2, 95% CI, 6.3-52.2; P < .001), aneurysm-related mortality (HR, 8.7; 95% CI, 1.8-41.6; P = .007), AAA rupture (HR, 21.7; 95% CI, 2.8-166; P = .003), and GRAEs (HR, 4.4; 95% CI, 2.0-9.7; P < .001). An IFU violation regarding neck angulation was also a risk factor for all-cause mortality (HR, 2.0; 95% CI, 1.1-3.7; P = .032), aneurysm-related mortality (HR, 7.6; 95% CI, 1.4-42.8; P = .021), AAA rupture (HR, 79.4; 95% CI, 6.3-999; P = .001), and GRAEs (HR, 4.3; 95% CI, 1.9-9.5; P < .001). The prevalence of EVAR performed outside the IFU did not increase over time. ConclusionsPerforming EVAR outside the IFU had a negative effect on outcomes, including all-cause mortality, aneurysm-related mortality, AAA rupture, and GRAEs. Neck angulation and neck length seemed to be the most crucial aneurysm characteristics.

Anatomical suitability and off-label use of contemporary transcatheter heart valves

BackgroundDespite excellent procedural results in a broad clinical population, certain anatomical or clinical conditions are still challenging for transcatheter aortic valve replacement (TAVI). Whether the adherence to the instructions for use (IFU) or the use of a clinically suitable device is a prerequisite for procedural success has not been well characterized. AimsThe anatomical and clinical suitability of new-generation transcatheter heart valves (THV) was evaluated in an all-comers population (n = 540) at a high-volume center. MethodsConformity with anatomical IFU criteria was evaluated in each implanted THV. In addition, the suitability of the implanted THV was verified in each case according to clinical and anatomical criteria, which had been previously defined according to the results of an international survey including 20 renowned TAVI operators. Furthermore, criteria of clinical suitability and adherence to IFU of each THV were applied to the overall cohort to analyze the proportion of patients in whom the use of the respective THV would have been judged to be unsuitable or off-label. ResultsAn off-label use of THV based on anatomical considerations was found in 20% of all procedures, whereas the implantation of a THV deemed to be clinically unsuitable was noted in 16.3% of all procedures. Clinical suitability and conformity with IFU were present to a varying extent across the THV systems. Neither clinical suitability, nor conformity with IFU were associated with device failure or periprocedural mortality. On multivariable analysis, aortic tortuosity, mean transaortic gradient and ascending aorta diameter were identified as independent predictors of device failure (VARC-3). ConclusionsOff-label TAVI and the use of clinically unsuitable THVs were common, but did not affect procedural outcomes. The variety of clinical and anatomical coverage of the different THV systems emphasizes the importance of an individualized THV selection.

Long-term implications of elective evar that is non-compliant with clinical practice guideline diameter thresholds

ObjectiveCompliance with Society for Vascular Surgery (SVS) abdominal aortic aneurysm (AAA) clinical practice guideline (CPG)-diameter thresholds is variable for endovascular aneurysm repair (EVAR). To evaluate the implications and appropriateness of repairs that are noncompliant with current guidelines, we investigated the long-term outcomes, adherence to imaging follow-up, and associated health care costs in patients undergoing EVAR for AAA who do or do not meet recommended diameter thresholds. MethodsAll patients receiving elective EVAR from 2003 to 2016 in the SVS Vascular Quality Initiative with linked Medicare claims were reviewed. Weekend procedures and isolated iliac aneurysms, as well as symptomatic and ruptured presentations, were excluded. Diameter thresholds for noncompliant repairs were defined as: men <55 mm; women <50 mm who did not have an iliac diameter ≥30 mm. We evaluated adherence to postoperative imaging surveillance, reimbursement amounts, reintervention, rupture, and all-cause mortality. We defined an EVAR quality metric as performance of the index procedure with freedom from conversion to open repair, 5-year rupture-free survival, and adherence to minimum imaging surveillance (at least one computed tomography scan documented between 6 and 24 months postoperatively). ResultsAmong 19,018 elective EVARs, 35% did not meet CPG diameter thresholds (26% within 5 mm of threshold). The rate of noncompliant repairs increased over time (24% in 2003 vs 36% in 2016; P < .001). Patients undergoing noncompliant repairs were younger, less likely to have multiple comorbidities, and more likely to receive EVAR with adherence to instructions for use criteria (89% vs 79%; P < .001). Patients undergoing noncompliant repairs had greater 5-year freedom from reintervention (86% vs 81%; P < .001), rupture-free survival (94% vs 92%; P = .01), and overall survival rates (71% vs 61%; P < .001) compared with repairs that complied with CPG diameter thresholds. Although noncompliant repairs had higher rates of 1-year imaging surveillance, overall differences were modest (68% vs 65%; P = .003). Importantly, for the entire cohort, follow-up imaging surveillance decreased over time (93% in 2003 vs 63% in 2014; P < .001). Notably, although noncompliant repairs had higher rates of achieving the composite quality metric compared with compliant repairs (43% vs 38%; P < .001), failure occurred with a significant majority of all repairs. ConclusionsCompliance with SVS-endorsed CPG diameter thresholds for elective EVAR is poor, and rates of noncompliance are increasing. Noncompliant repairs appear to be offered more commonly to patients with fewer comorbidities and favorable anatomy, and these repairs are associated with improved rates of reintervention, rupture, and survival compared with procedures meeting CPG diameter thresholds. Importantly, noncompliant repairs fail to meet minimum quality standards in a majority of cases, which underscores the need for further policies to improve the overall quality and appropriateness of AAA care delivery nationally.

Contemporary Indications for Open Abdominal Aortic Aneurysm Repair in the Endovascular Era

Despite the emergence of endovascular abdominal aortic aneurysm repair (EVAR) as the most common approach to repair, open aneurysm repair (OAR) remains a critical option. We sought to define the indications for OAR in the EVAR era and how these indications affect the outcomes. We performed a retrospective review of all OAR cases at a single institution from 2004 to 2020. Preoperative computed tomography scans and operative records were assessed to determine the indications for OAR. These reasons were categorized into anatomic contraindications, systemic factors (ie, connective tissue disorders, contraindication to contrast dye), and patient and/or surgeon preference (candidates for both EVAR and OAR). The perioperative and long-term outcomes were compared. A total 370 patients were included in the analysis. Of the 370 patients, 265 (71.6%) had at least one anatomic contraindication to EVAR (36% had two or more contraindications). The most common anatomic contraindications were a short aortic neck length (51.6%), an inadequate distal seal zone (19.2%), and inadequate access vessels (15.7%). The major perioperative complication rate was 18.1%, and the 30-day mortality was 3.6%. No single anatomic factor was identified as a predictor of perioperative complications. Sixty-one patients (16.5%) had undergone OAR by patient and/or surgeon preference. These patients were younger, had a lower incidence of coronary artery disease and chronic obstructive pulmonary disease, and were less likely to require suprarenal cross-clamping than were the patients who had had anatomic and/or systemic contraindications to EVAR. The patient/surgeon preference group had a lower incidence of perioperative major complications (8.2% vs 20.1%; P = .034), a shorter length of stay (6 vs 8 days; P < .001), and no 30-day mortality. The multivariable adjusted risk for 15-year mortality was lower for the patient/surgeon preference group (19.7% vs 39.5%; adjusted hazard ratio, 0.44; 95% confidence interval, 0.24-0.80; P = .007) than for the anatomic/systemic contraindications group (Table). Within a population of patients who did not meet the instructions for use criteria for EVAR, no single anatomic contraindication was a marker for worse outcomes after OAR. Patients who were candidates for both aortic repair approaches but who had elected to undergo OAR had 30-day mortality of 0% and superior perioperative morbidity and long-term survival rates.TableShort- and long-term outcomes stratified by OAR indicationVariableSurgeon/patient preference (n = 61)Anatomical/systemic contraindication (n = 309)P valueEstimated blood loss, mL1177 ± 9531656 ± 1653.060ICU LOS, days2 (1-2)2 (1-4).14Hospital LOS, days6 (6-9)8 (6-11)<.00130-day mortality0 (0)11 (3.6).22Long-term outcomes, adjusted 15-Year death12 (19.7)122 (39.5).007ICU, Intensive care unit; LOS, length of stay; OAR, open aneurysm repair.Data presented as mean ± standard deviation, median (interquartile range), or number (%). Open table in a new tab

Aortic Neck IFU Violations During EVAR for Ruptured Infrarenal Aortic Aneurysms are Associated with Increased In-Hospital Mortality

Vascular surgeons treating patients with ruptured abdominal aortic aneurysm must make rapid treatment decisions and sometimes lack immediate access to endovascular devices meeting the anatomic specifications of the patient at hand. We hypothesized that endovascular treatment of ruptured abdominal aortic aneurysm (rEVAR) outside manufacturer instructions-for-use (IFU) guidelines would have similar in-hospital mortality compared to patients treated on-IFU or with an infrarenal clamp during open repair (ruptured open aortic aneurysm repair [rOAR]). Vascular Quality Initiative datasets for endovascular and open aortic repair were queried for patients presenting with ruptured infrarenal AAA between 2013-2018. Graft-specific IFU criteria were correlated with case-specific proximal neck dimension data to classify rEVAR cases as on- or off-IFU. Univariate comparisons between the on- and off-IFU groups were performed for demographic, operative and in-hospital outcome variables. To investigate mortality differences between rEVAR and rOAR approaches, coarsened exact matching was used to match patients receiving off-IFU rEVAR with those receiving complex rEVAR (requiring at least one visceral stent or scallop) or rOAR with infrarenal, suprarenal or supraceliac clamps. A multivariable logistic regression was used to identify factors independently associated with in-hospital mortality. 621 patients were treated with rEVAR, with 65% classified as on-IFU and 35% off-IFU. The off-IFU group was more frequently female (25% vs. 18%, P = 0.05) and had larger aneurysms (76 vs. 72 mm, P= 0.01) but otherwise was not statistically different from the on-IFU cohort. In-hospital mortality was significantly higher in patients treated off-IFU vs. on-IFU (22% vs. 14%, P= 0.02). Off-IFU rEVAR was associated with longer operative times (135 min vs. 120 min, P= 0.004) and increased intraoperative blood product utilization (2 units vs. 1 unit, P= 0.002). When off-IFU patients were matched to complex rEVAR and rOAR patients, no baseline differences were found between the groups. Overall in-hospital complications associated with off-IFU were reduced compared to more complex strategies (43% vs. 60-81%, P< 0.001) and in-hospital mortality was significantly lower for off-IFU rEVAR patients compared to the supraceliac clamp group (18% vs. 38%, P= 0.006). However, there was no significantly increased mortality associated with complex rEVAR, infrarenal rOAR or suprarenal rOAR compared to off-IFU rEVAR (all P> 0.05). This finding persisted in a multivariate logistic regression. Off-IFU rEVAR yields inferior in-hospital survival compared to on-IFU rEVAR but remains associated with reduced in-hospital complications when compared with more complex repair strategies. When compared with matched patients undergoing rOAR with an infrarenal or suprarenal clamp, survival was no different from off-IFU rEVAR. Taken together with the growing available evidence suggesting reduced long-term durability of off-IFU EVAR, these data suggest that a patient's comorbidity burden should be key in making the decision to pursue off-IFU rEVAR over a more complex repair when proximal neck violations are anticipated preoperatively.

Early results of expanding the anatomical indications for using a Gore Iliac branch endoprosthesis to treat aortoiliac and iliac aneurysms.

To assess the safety and anatomical suitability of using a Gore Iliac Branch Endoprosthesis (IBE) in aortoiliac and iliac aneurysm repair. Between 2017 and 2020, 20 patients underwent endovascular aneurysm repair (EVAR) with a Gore IBE device (bilateral IBE, n = 1) after expanding the instructions for use (IFU) criteria. We evaluated the early clinical outcomes and suitability of the IFU criteria, retrospectively. Six patients (30%) met all the IFU criteria. Anatomical suitability according to the IFU criteria for the collective total of 21 IBE limbs was confirmed for 10 (47.6%) proximal common iliac arteries, 21 (100%) external iliac arteries, 18 (85.7%) internal iliac arteries, and in the length from the lowest renal artery to the iliac bifurcation in 15 (71.8%) patients. Assisted primary technical success was achieved in all patients with various bail-out techniques. One patient (5%) required a bare-stent insertion 7days after EVAR for severe stenosis in the ipsilateral limb caused by a small terminal aorta. There was no case of occlusion of an iliac branch component device. Gore IBEs were implanted safely and effectively with various bail-out techniques to repair aortoiliac and iliac aneurysms in our Japanese patients with a low rate of inclusion IFU criteria.

Utility of Single-Branched Thoracic Endograft in Patients Requiring Zone 2 Seal During Thoracic Endovascular Aortic Repair

Single-branched thoracic endografts (SBTEs) are under investigation for treatment of thoracic aortic disease that requires zone 2 seal during thoracic endovascular aortic repair (TEVAR). A variety of anatomic criteria must be met for their effective implantation. Our aim was to analyze anatomic suitability for SBTE. We performed a retrospective review of 103 TEVAR procedures in 88 patients at our academic referral center between 2017 and 2019. Proximal seal was achieved in zone 3 or zone 4 (n = 37 [36%]), zone 2 (n = 30 [29%]), or zone 0 or zone 1 (n = 36 [35%]). We analyzed the zone 2 group’s operative angiograms and preoperative computed tomography angiograms using centerline software to measure arterial diameters and length in relation to the left common carotid artery, left subclavian artery (LSA), and proximal extent of aortic disease to determine whether patients met anatomic criteria using the instructions for use (IFU) of the Navion Mona LSA (Medtronic, Santa Rosa, Calif; Table I). Average age in the zone 2 group was 64 years (range, 26-85 years); 17 were male (57%). Indications (Table II) were acute type B dissection (ATBD; n = 13 [43%]), aneurysm (n = 15 [50%]), and blunt aortic injury (n = 2 [7%]). The LSA was revascularized in 20 (67%): carotid subclavian bypass or transposition, n = 17; laser fenestration, n = 3. Overall, 14 (47%) of the zone 2 patients met the IFU. Reasons for failure are listed in Table I. Of the 16 who did not meet IFU, 9 had multiple exclusion criteria. Inadequate aortic diameter excluded only the two blunt aortic injury patients. The proportion of patients who met IFU criteria by indication are listed in Table II. Fewer ATBDs (5/13 [38%]) met IFU than aneurysms (9/15 [60%]), but this was not statistically significant (P = .26). Of the eight ATBD patients who failed to meet criteria, seven had dissection at or into the origin of the LSA. If dissection into the LSA origin was allowed in ATBD, three of the seven would have otherwise qualified. Approximately half of patients who require TEVAR seal in zone 2 meet criteria for this SBTE. The device may offer the ability to provide flow to the LSA without the need for adjuvant revascularization procedures. Patients with aneurysms more often met the IFU than those with acute dissection. A modification to the IFU to allow dissection up to the LSA origin would increase eligibility in ATBD by >50%. Clinical efficacy data, however, are needed to determine whether this would be effective.Table IAnatomic criteria for the Navion Mona LSAAnatomic criteriaCriteria to meet IFUMean ± SD, mmNo. (%) failing to meet criteriaAortic diameter at proximal seal zoneDissection: 28-44 mm Aneurysm/PAU: 25-42 mm30.2 ± 3.82 (7)LSA diameter8-13 mm9.47 ± 1.30 (0)Distance between orifices of LCCA to LSA≥10 mm10.9 ± 6.012 (40)Distance of LCCA to aortic disease≥20 mm22.1 ± 10.111 (37)Distance of LSA to aortic disease≥0 mm (presence of nondiseased aorta distal to LSA)5.6 ± 6.311 (37)IFU, Instructions for use; LCCA, left common carotid artery; LSA, left subclavian artery; PAU, penetrating aortic ulcer; SD, standard deviation. Open table in a new tab Table IIThoracic endovascular aortic repair (TEVAR) indications and proportion that met the instructions for use (IFU)IndicationNo.No. (%) meeting criteriaAcute type B dissection135 (38)Aneurysm or penetrating ulcer96 (67)Aneurysm in chronic dissection63 (50)Blunt aortic injury20 (0) Open table in a new tab

Endovascular Aneurysm Sealing Therapy with the Nellix System in Patients Not Suitable for Conventional EVAR – A Single Centre Experience

Objective: Endovascular aneurysm sealing (EVAS) therapy with the Nellix system was introduced in 2013. In January 2019, the Medicines and Healthcare Regulatory Authority issued a Field Safety Notice to desist use. The aim was to review experience in the use of the Nellix device in a specific cohort of patients. Methods: A prospective study of 27 patients who underwent EVAS with the Nellix system in the Belfast Trust between December 2013 and January 2016. Use of the Nellix system was approved by the Trust Standards and Guidelines Committee. All cases were deemed not suitable for conventional endovascular aneurysm repair and judged suitable for EVAS by the product specialists as per the 2013 instructions for use criteria. Results: Up to April 2019, 17/27 patients had died. Three with confirmed ruptured AAA within an average of 1.8 years. The others were non-AAA related deaths. Four of 27 (14.8%) patients had a type I endoleak on first surveillance imaging, increasing to 10/27(37%) patients on follow up imaging. One out of 27 (3.7%) developed sac expansion. Of the 10 surviving patients, seven have an aneurysm related complication (six endoleaks and one sac expansion). One patient went on to rupture with successful conversion to open repair. Three patients were deemed not suitable or declined further intervention. The remainder of surviving patients will continue on yearly surveillance or await clinical review. Conclusion: The Nellix system is associated with unacceptably high morbidity and mortality rates in this specific cohort. While new technology is essential to progressing healthcare, specialised consent and stringent surveillance strategies are required when adopting new techniques.

Suitability of the Aortic Neck Anatomy for Endovascular Aneurysm Repair in Korean Patients with Abdominal Aortic Aneurysm.

PurposeTo evaluate the aortic neck anatomy in Korean patients with abdominal aortic aneurysms (AAAs).Materials and MethodsWe examined computed tomography scans of 343 patients with AAAs (≥5.5 cm for men or ≥5 cm for women) between 2009 and 2018. Eligibility of neck anatomy for endovascular aneurysm repair (EVAR) was assessed with the standard instructions for use (IFU) (length ≥15 mm, suprarenal angulation (SRA) ≤45°, infrarenal angulation (IRA) ≤60°, and diameter 18-32 mm) and the extended IFU (length ≥10 mm, SRA ≤60°, IRA ≤75°, and diameter 17-32 mm).ResultsThere were 71 women (20.7%), and 61 patients (17.8%) with rupture. Women had smaller neck diameters (21.3 vs. 23.4 mm, P<0.001 for proximal neck; 22.2 vs. 24.5 mm, P<0.001 for distal neck), and higher angulations (51.5° vs. 37.8°, P<0.001 for SRA; 77.7° vs. 57.0°, P<0.001 for IRA) than men. However, the neck length was not significantly different. Patients with ruptured AAAs had shorter neck lengths (21.0 vs. 26.8 mm, P=0.005) than those with intact AAAs. However, the neck diameters and angulations were not significantly different. EVAR eligibility for standard and extended IFUs was found in 37.5% and 55.1% of men, and 11.3% and 25.4% of women (P<0.001 for both IFUs); neck anatomy was eligible in 34.0% of intact AAAs and 23.0% of ruptured AAAs (P=0.098).ConclusionA significant proportion of the Korean patients did not meet the IFU for EVAR, mainly due to the angulated neck. Women, and patients with ruptured AAAs, were less likely to meet the IFU criteria.

Impact of Compliance with Anatomical Guidelines of "Bell-Bottom" Iliac Stent Grafts for Ectatic or Aneurysmal Iliac Arteries.

To evaluate the impact of compliance with anatomical guidelines on outcomes of endovascular aortic aneurysm repair using "bell-bottom" stent grafts (BBSGs). This is a retrospective review from January 1999 to May 2012 of patients who underwent endovascular infrarenal abdominal aneurysm repair and whose iliac limbs were greater than 18mm in diameter. Computed tomography angiography was utilized for compliance with anatomical guidelines as stated in manufacturer's instructions for use (IFU). The primary outcome observed was iliac limb events. The secondary outcome observed was the need for re-intervention due to BBSG failure. Of the 376 BBSGs,55 (15%) in 27 patients met IFU. Aneurysm exclusion was achieved in all patients.The mean follow-upwas 44 ± 30months. Twenty-eight patients (11%) had 29 iliac limb events (12 type 1b endoleaks, 4 aneurysm sac growth, 4 stenosis/kink, 4 retrograde migrations, 2 component separations, 2 ruptures and 1 limb occlusion); all among patients treated outside of IFU (p < 0.04). The rate of aneurysm sac enlargement was similar between both groups, at 56%, respectively, between those treated within and those treated outside of IFU. On multivariate regression analysis, largercommon iliac artery (CIA)(HR 1.088, 95% CI 1.016-1.166, p = 0.016), greater CIA tortuosity (HR 2.352, 95% CI 1.004-5.509, p = 0.048) and limbs with more than two characteristics that did not meet IFU criteria (HR 3.84, 95% CI 1.15-12.83, p = 0.03) were associated with higher rates of BBSG events and re-interventions. BBSGs effectively seal ectatic CIAs. But rates of iliac limb events and re-interventions are higher among patients who do not meet IFU criteria. The larger CIA diameter, the greater CIA tortuosity and more than two criteria not met by IFU were associated with BBSG failure and re-intervention.

Long-term survival after endovascular and open repair in patients with anatomy outside instructions for use criteria for endovascular aneurysm repair

BackgroundRandomized controlled trials of long-term survival for infrarenal abdominal aortic aneurysms have compared open surgical repair (OSR) with endovascular aneurysm repair (EVAR) in patients with suitable aortic anatomy for EVAR. However, in clinical practice, patients who do not meet instructions for use (IFU) criteria are often still treated by EVAR despite that some studies show higher graft-related adverse events. The goal of this study was to compare the long-term survival of EVAR and OSR in patients with anatomy outside IFU criteria for EVAR. MethodsThis multicenter retrospective cohort study included patients with at least one anatomic IFU violation for EVAR undergoing either elective EVAR or elective OSR for abdominal aortic aneurysm. Demographics, anatomic data, and follow-up data of patients were collected from three academic centers from 2003 to 2016. Device-specific IFU were used for EVAR patients, whereas generic IFU for EVAR were applied to the OSR patients. The primary outcomes were 30-day mortality and long-term all-cause mortality. Secondary outcomes were aneurysm-related mortality and perioperative complications at 30 days. Kaplan-Meier survival and Cox proportional hazards modeling were performed. Inverse propensity score weights were used to adjust for differences in treatment selection. ResultsThe study population included 202 EVAR patients and 224 OSR patients with at least one anatomic IFU violation for EVAR. EVAR patients were older (78.1 ± 7.3 vs 70.9 ± 7.0 years; P < .001) and less likely to be hypertensive (69.3% vs 79.0%; P = .02) compared with OSR patients. OSR patients were more likely to have proximal aortic neck IFU violations (75.0% vs 47.1%; P < .001) and were less likely to have iliac IFU violations (65.2% vs 79.2%; P < .001). All-cause mortality was 37.6% in the EVAR group and 24.1% in the OSR group with a median follow-up time of 5.2 (3.5-7.2) and 5.4 (2.8-9.3) years, respectively (P < .002). Kaplan-Meier survival analysis revealed a significant association between patients undergoing OSR and increased long-term survival (log-rank P < .0001). When adjusted for possible confounders and weighted for propensity for treatment through Cox hazard modeling, the association remained significant (hazard ratio, 0.6; 95% confidence interval, 0.4-0.9). Aneurysm-related mortality was 3.5% in the EVAR group and 2.2% in the OSR group during long-term follow-up (P < .001). ConclusionsOur study identified that patients with IFU violations have higher overall long-term survival with open surgery compared with EVAR. Caution should be applied in considering standard EVAR for patients with anatomy outside of IFU.

Anatomic eligibility for transcarotid artery revascularization and transfemoral carotid artery stenting

ObjectiveTranscarotid artery revascularization (TCAR) has emerged as an alternative to transfemoral carotid artery stenting (tfCAS). We investigated the proportion of carotid arteries undergoing revascularization procedures that would be eligible for TCAR based on anatomic criteria and how many arteries at high anatomic risk for tfCAS would be amenable to TCAR. MethodsWe performed a retrospective review of consecutive patients who underwent carotid endarterectomy or carotid stenting between 2012 and 2015. Patients were excluded if computed tomography angiography of the neck was not performed within 6 months of the procedure. We assessed TCAR eligibility on the basis of the instructions for use of the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical, Sunnyvale, Calif) and high anatomic risk for tfCAS on the basis of anatomic factors known to make carotid cannulation more difficult or hazardous. ResultsOf the 118 patients and 236 carotid arteries identified, 12 carotid arteries were excluded for presence of an occluded internal carotid artery (ICA). Of the remaining 224 carotid arteries, 72% were eligible for TCAR on the basis of the instructions for use criteria; 100% had 4- to 9-mm ICA diameters, 100% had ≥6-mm common carotid artery (CCA) diameter, 75% had ≥5-cm clavicle to carotid bifurcation distance, and 96% lacked significant CCA puncture site plaque. In addition, 7% of carotid arteries had bifurcation anatomy unfavorable for stenting; thus, of the entire cohort of arteries examined, 68% were eligible for TCAR. Hyperlipidemia (odds ratio [OR], 6.7; 95% confidence interval [CI], 1.7-26; P < .01), chronic obstructive pulmonary disease (OR, 3.5; 95% CI, 1.5-8.3; P < .01), and older age (OR, 1.1; 95% CI, 1.0-1.1; P < .01) were independently associated with TCAR ineligibility, whereas white race (OR, 0.2; 95% CI, 0.0-1.0; P = .048) and beta-blocker use (OR, 0.3; 95% CI, 0.1-0.7; P < .01) were independently associated with TCAR eligibility. In addition, 24% of carotid arteries were considered to be at high risk for tfCAS for the presence of a type III aortic arch (7.6%), severe aortic calcification (3.3%), tandem CCA lesions (7.1%), moderate to severe stenosis at the carotid ostium (8.9%), and tortuous distal ICA precluding embolic filter placement (4.5%). Active smoking (OR, 4.4; 95% CI, 1.9-10; P < .01), hyperlipidemia (OR, 4.0; 95% CI, 1.2-14; P = .03), and older age (OR, 1.1; 95% CI, 1.0-1.1; P = .02) were independently associated with tfCAS ineligibility, whereas preoperative aspirin (OR, 0.1; 95% CI, 0.0-0.4; P < .001) or clopidogrel (OR, 0.3; 95% CI, 0.1-0.8; P = .01) use was associated with tfCAS eligibility. Of the arteries that were considered to be at high risk for tfCAS, 69% were eligible for TCAR. ConclusionsThe majority of carotid arteries in individuals selected for revascularization meet TCAR eligibility, making TCAR a viable treatment option for many patients.

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

BackgroundThe 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. MethodsComprehensive 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. ResultsFreedom 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). ConclusionsConsistent 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.

Outcomes of Endovascular Aneurysm Repair using the Ovation Stent Graft System in Adverse Anatomy

The aim was the evaluation of mid-term efficacy and safety outcome measures for the Ovation (Endologix, Santa Rosa, CA, USA) stent graft system in the management of infrarenal abdominal aortic aneurysms (iAAA) with adverse anatomy. A retrospective observational study of all patients undergoing elective iAAA repair was carried out from 2012 to 2017 using Ovation Prime or iX stent grafts with a minimum of 3 months follow-up at a single UK vascular centre. Post-operative surveillance involved computed tomography scans at 3 months and 1 year, with duplex ultrasound yearly thereafter. Outcome measures were established with retrospective analysis of pre- and post-operative imaging, and included peri-operative mortality, major adverse events, limb complications, aneurysm diameter change, and endoleak rates. All patients were within Ovation instructions for use (IFU), and assessment was made to determine whether aneurysms had anatomical features considered adverse for other commonly used stent graft platforms. Ovation stent grafts were implanted in 52 patients (79% male, mean age 75.7 years) with a mean aneurysm diameter of 62.5mm (range 55-107mm). There was 100% technical deployment success. The 30 day mortality was 0% and there was no aneurysm related mortality during follow-up (median 24 months, range 3-48 months). There were no type I or III endoleaks, but 19% developed type II endoleaks with one patient requiring re-intervention. No iliac limb occlusions were identified but one case required relining for limb kinking. All 52 cases were within the IFU for Ovation but only 12% met the IFU criteria for the Cook and Medtronic devices. The mid-term experience with Ovation demonstrates safe, durable treatment of iAAAs, including those with unfavourable anatomy, frequently off IFU for other commonly used devices.

Anatomic characteristics of abdominal aortic aneurysms presenting with delayed rupture after endovascular aneurysm repair

Endovascular aneurysm repair (EVAR) has become the mainstay of treatment for abdominal aortic aneurysms (AAAs) requiring repair. Delayed rupture after EVAR represents a rare but potentially fatal complication. The purpose of this study was to review the frequency and characteristics of patients presenting with secondary rupture and to define the relationship between rupture after EVAR and initial compliance with instructions for use (IFU). This is a retrospective study of a prospectively maintained database. Patients presenting with delayed rupture after EVAR were identified from January 2002 to December 2014. Medical records and imaging were reviewed to define anatomic characteristics and compliance with IFU criteria. Demographics, comorbidities, preoperative imaging, and long-term outcomes were analyzed. Patients were divided into two groups according to compliance with IFU criteria. Outcomes included type of repair (open vs secondary endovascular) as well as perioperative morbidity and mortality. A total of 3081 patients underwent EVAR for AAA from 2002 to 2014. Of the 3081 patients, 45 experienced delayed rupture after EVAR. The mean time interval between initial repair and rupture was 38months. All patients with delayed ruptures had a type Ia endoleak. Mean follow-up after secondary repair was 44.1months, and overall mortality was 6.7% (n= 3). Patients were divided in two groups according to compliance with IFU criteria: within the IFU and outside the IFU. There was no significant difference in comorbidities between the two groups except smoking, which was more frequent in the outside the IFU group (25% vs 21%; P= .03). Patients repaired outside the IFU had a higher incidence of type Ia endoleak before presenting with a rupture (44% vs 6%; P= .001), more frequently required open repair (44% vs 12%; P= .002), and had higher perioperative mortality (10.3% vs 0%; P= .01). On review of preoperative computed tomography scans, the outside the IFU group had larger aneurysm sac diameters (7.2 vs 5.6cm; P= .04), larger proximal neck diameters (28 vs 24mm; P= .01), shorter proximal necks (12 vs 21mm; P= .007), and a higher degree of neck angulation >40 degrees (56 vs 11%; P< .001). Delayed rupture after EVAR is a rare but potentially fatal complication. In patients presenting with secondary rupture, EVAR performed outside the IFU was associated with higher perioperative mortality and need for open repair. Careful selection of patients based on AAA anatomy and adherence to the IFU criteria may reduce the incidence of delayed rupture.

No major difference in outcomes for endovascular aneurysm repair stent grafts placed outside of instructions for use

Studies have shown that a sizable percentage of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) is performed outside the instructions for use (IFU). We report our long-term outcomes after EVAR with respect to device-specific IFU. Computed tomography angiography data from a cohort of 566 patients meeting inclusion criteria who underwent elective EVAR between 2003 and 2014 were examined. Preoperative anatomic measurements for each patient were taken and compared with device-specific IFU. Primary outcomes included all-cause mortality and AAA-related mortality. Secondary outcomes were late-onset rupture, need for reintervention, endoleaks, aneurysm sac enlargement, and intraoperative and perioperative complications. Nine different stent grafts were placed in this set of patients with a mean follow-up of 3.54± 2.65years. Most patients (465; 82.2%) were male, and the mean age was 74.8± 8.70years. Overall, 176 patients (31.1%) fit all IFU anatomic criteria, and 535 patients (94.5%) fit at least half of IFU criteria. In patients, iliac artery diameter was most commonly outside of IFU (253; 44.7%). A total of 1114 iliac arteries were treated, with 463 (41.6%) treated outside of iliac artery diameter IFU; the majority of these (374; 80.7%) were larger than IFU. Demographics and comorbidities were comparable between the groups within and outside of IFU. AAA-related mortality and all-cause mortality were similar between these two groups, as was late-onset rupture, need for reintervention, rates of endoleak, aneurysm sac enlargement, and major intraoperative and perioperative complications. The sole statistically significant difference in secondary outcomes was increased perioperative blood transfusion needed in those treated outside the IFU, 13.2% vs 6.2% in those treated within IFU (P= .02); however, this was not associated with decreased access vessel diameter or iliac artery rupture. Despite most EVAR patients being treated outside of IFU, there was no difference in outcomes with respect to all-cause mortality or aneurysm-related mortality. In addition, with the exception of perioperative blood transfusions, there was no association between IFU adherence and late-onset rupture, need for reintervention, rates of endoleak, aneurysm sac enlargement, or most other major complications.

Management of Aortic Aneurysms: Is Surgery of Historic Interest Only?

Since its advent in 1991, endovascular aortic aneurysm repair (EVAR) has become a mainstay of treatment for abdominal aortic aneurysms (AAA). Studies such as the comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR 1) trial, have demonstrated the effectiveness of EVAR in reducing perioperative mortality. Technological improvements in graft design and delivery account for an increasing utilization of endovascular repair. Newer branch and fenestrated graft designs have allowed for treatment of patients with complex aortic anatomy that previously could not be treated with EVAR. Endovascular repair, while dominant, is unlikely to eliminate the need for open repair or to relegate open surgery for AAA to historical interest only. The unprecedented adoption of EVAR has led to complications and modes of failure that were not seen with open repair. The rate of failure is markedly increased when endografts are used outside of the instructions for use (IFU). The long-term durability of fenestrated and investigational branch devices remains to be established. The demand for an endovascular approach by patients and the willingness of physicians to place endografts outside the anatomic IFU criteria may have resulted in the pendulum swinging too far away from open surgical management. The consequence of reduced open aortic surgeries is a concern for both patient care as well as training for vascular surgery fellows. Vascular surgery training programs will require innovative changes in training to assure that vascular surgery trainees will have the requisite skill and experience required to competently perform open surgical repair on what will undoubtedly be some of the most complex aortic pathology.