Aortic Neck Diameter Research Articles

Endovascular versus open repair of ruptured abdominal aortic aneurysms with hostile neck anatomy

ObjectiveAneurysm neck anatomy in ruptured abdominal aortic aneurysms (rAAAs) is often complex, limiting the feasibility of endovascular repair (EVAR). The objective of this study was to compare the outcomes of EVAR and open surgical repair (OSR) for treatment of rAAAs in patients with hostile neck anatomy (HNA). The secondary aim was to review the clinical characteristics and anatomic risk factors predictive of mortality. MethodsA multi-center retrospective review was performed to identify patients with rAAAs and HNA between 2004 and 2021. HNA was defined as infrarenal aortic neck diameter >28 mm, infrarenal neck length <15 mm or angulation >60 degrees. The primary end point was 30-day all-cause mortality. Secondary end points included 90-day, 1-year and 5-year mortality. Preoperative computed tomography was analyzed using an Aquarius workstation. The Kaplan-Meier method was used to estimate survival, and univariate and multivariate Cox proportional hazard regression analysis was used to assess variables that influenced survival. Results137 patients with rAAAs and HNA underwent infrarenal EVAR or OSR. Overall mean age was 74 ± 10 years and 72% were male. 85 patients (62%) underwent infrarenal EVAR and 52 (38%) underwent OSR. Mean aneurysm size at the time of rupture was 86 ± 22 mm. Patients who underwent OSR were more likely to present with a higher Garland preoperative risk score (P = .05), have a lower pH (P < .001), lower SBP (P < .001) and higher lactate (P = .005). Patients with an infrarenal neck length <15 mm were more likely to undergo OSR (EVAR 64% vs. OSR 87%, P = .004) and patients with an infrarenal neck angle >60 degrees were more likely to undergo EVAR (60% vs. 39%, P = .01). EVAR was associated with lower 30-day (17% vs. 27%; OR 0.6; 95% CI, 0.3-1.2; P = .14) and 90-day (22% vs. 33%; HR 0.6; 95% CI, 0.3-1.2; P = .17) all-cause mortality, however, this was not statistically significant. The overall median follow-up time was 19 (2-66) months. 1-year survival for EVAR and OSR were 75% and 64% (Log-rank P = .14) and 5-year survival for EVAR and OSR were 65% and 55% (Log-rank P = .28). Hemoglobin (P = .009), increasing calcification score (P = .002) and infrarenal neck length <10 mm (P = .01) were associated with all-cause mortality at 30-days for EVAR on multivariate Cox regression analysis. Lactate (P <.001) was the only variable associated with all-cause mortality at 30-days for OSR on multivariate Cox analysis. ConclusionEarly and long-term survival favored EVAR in comparison to OSR in patients with rAAAs and HNA, however, this was not statistically significant. Calcification of the infrarenal neck and neck length <10 mm were associated with increased 30-day mortality for EVAR while no anatomic variables were specifically associated with 30-day mortality for OSR.

Midterm Outcomes for Funnel-EVAR.

The funnel technique, the hybrid assembly of a thoracic and abdominal aortic endograft, is advantageous for frail patients where efficient oversizing is not possible for infrarenal wide aortic necks over 34 mm. We sought to determine the advantages and disadvantages of the Funnel-endovascular aneurysm repair (EVAR) technique using 60 mm length thoracic endograft. This retrospective study included 22 patients, all frail with high comorbidities, who were operated on with the Funnel technique using the 60 mm Lifetech Ankura thoracic endograft, in 7 urgent and 15 elective cases from January 2018. There were no exclusion criteria except having an age 60 years. Primary endpoints were the technical success and early mortality and morbidity; secondary endpoints were late outcomes such as endoleak, migration, late open surgical conversion, successful sac shrinkage, and enlargement at the infrarenal aortic neck diameter. The patients' mean age was 72.6 7.3 years (62-86 years), with a mean aneurysm diameter of 83.2 16.8 mm and mean infrarenal aortic diameter of 38.7 2.4 mm. There was no early mortality. Technical success was 100%. 21 standard bifurcated and one aorto-uni-iliac abdominal endograft were deployed. The mean fluoroscopy time was 14.3 5.2 minutes. Mean follow-up was 32.8 19.6 months, with no endovascular complications. There was no Type-1a or Type-3 endoleak, migration, infrarenal aortic neck diameter enlargement, or aneurysm sac enlargement. During the follow-up, three patients died, but there was no aneurysm-related mortality. Funnel-EVAR is effective and safe for patients with a wide infrarenal aortic neck diameter when assessing midterm outcomes. Therefore, it should be part of the armamentarium of a vascular surgeon in patients with wide aortic necks 34 mm.

Predictive Factors for Iliac Limb Occlusions After Endovascular Abdominal Aneurysm Repair: Determined from Aortoiliac Anatomy, Endovascular Procedures, and Aneurysmal Remodeling.

Iliac limb occlusion (ILO) is a serious complication of endovascular abdominal aneurysm repair (EVAR). This study aimed to identify predictive factors for ILO derived from aortoiliac morphology, endovascular procedure-related parameters, and aneurysmal remodeling characteristics. Patient demographics, pre-EVAR anatomical characteristics of the aneurysm, endovascular procedure details, and post-EVAR aneurysmal remodeling outcomes were analyzed and compared using univariate analysis. Statistically significant factors were subsequently subjected to Cox regression and Kaplan-Meier analyses. Between January 2013 and April 2022, 66 patients were included in this study. Fourteen patients presented with ILO and were compared with 52 control patients with patent endograft limb over at least 1-year of follow-up. The tortuosity indices of the common iliac artery (CIA) and endograft iliac limb to vessel oversizing were significantly larger in the ILO group than in the patent endograft limb group. The CIA index of tortuosity ≥1.08, and endograft iliac limb to vessel oversizing ≥18.8% were independent predictors for ILO. During the follow-up of all patients, the proximal aortic neck and CIA diameters increased, aneurysm sac diameter decreased, and aortic neck and aortic length increased. The aortoiliac length increased over time in patients with patent endograft limb but not in patients with ILO. A change in the lowest renal artery-left iliac bifurcation distance ≦0.07 mm increased the risk of ILO. ILO is predisposed to occur when the CIA index of tortuosity ≥1.08 and endograft iliac limb to vessel oversizing ≥18.8% are present. Significant aortoiliac remodeling, including proximal aortic neck dilatation, neck straightening, aneurysmal sac regression, iliac artery enlargement, and aortic lengthening, occurs after EVAR. Aortoiliac elongation was observed in patients with patent endograft limb, but not in patients with ILO. ILO was associated with a change in the lowest renal artery-left iliac bifurcation from the postoperative measurements ≦ 0.07 mm.

Use of physician-modified inverted limb in conjunction with Zenith fenestrated stent graft to rescue failed previous endovascular and open repair

ObjectiveTo evaluate outcomes and performance of inverted limbs (ILs) when used in conjunction with Zenith fenestrated stent grafts (Zfens) to treat patients with short distance between the lowest renal artery (RA) and aortic or graft bifurcation (A/GB). MethodsThis study was a multicenter, retrospective review of prospectively maintained database of patients with complex aortic aneurysms, failed endovascular aneurysm repair (EVAR), or open surgical repair (OSR) with short distance between LRA and A/GB treated using a combination of Zfen and an IL between 2013 and 2023. Endpoints included technical success, aneurysm sac regression, long-term device integrity, and target vessel patency. We defined technical success as implantation of the device with no endoleak, conversion to an aorto-uni-iliac or OSR. ResultsDuring this time, 52 patients underwent endovascular rescue of failed repair. Twenty (38.5%) of them required relining of the failed repairs using IL due to lowest RA to A/GB length restrictions. Two patients had undergone rescue with a fenestrated cuff alone but developed type III endoleaks. One patient with no previous implant had a short distance between the lowest RA and aortic bifurcation to accommodate the bifurcated distal device, and two patients had failed OSR or anastomotic pseudoaneurysms. The majority (94%) were men with a mean age of 76.8 ± 6.1 years. The mean aortic neck diameter and aneurysm size were 32 ± 4 cm and 7.2 ± 1.3 cm, respectively. The median time laps between initial repair and failure was 36 months (interquartile range [IQR], 24-54 months). Sixteen patients (80%) were classified as American Society of Anesthesiologists class III, whereas four were class IV. Seventy-eight vessels were targeted and successfully incorporated. Technical success was 100%, and median estimated blood loss was 100 mL (IQR, 100-200 mL). Mean fluoroscopy time and dose were 61 ± 18 minutes and 2754 ± 1062 mGy, respectively. Average hospital length of stay was 2.75 ± 2.15 days. Postoperative complication occurred in one patient who required lower extremity fasciotomy for compartment syndrome. At a median follow-up of 50 months (IQR, 18-58 months), there were no device migration, components separation, aneurysmal related mortality, and type I or type III endoleak. Aneurysm sac regression (95%) or stabilization (5%) was observed in all patients, including in four patients (25%) with type II endoleak. ConclusionsThe use of IL in conjunction with Zfen to treat patients with short distance between the lowest RA and A/GB is safe, effective, and has excellent long-term results. The technique expands the indication of Zfen, especially in patients with failed previous EVAR.

The impact of large proximal aortic neck on endovascular aneurysm repair outcomes

Background: This study aims to investigate the effect of large proximal aortic neck diameter on post-endovascular aneurysm repair clinical outcomes. Methods: A total of 180 patients (168 males, 12 females; mean age: 69.9±7.4 years; range, 46 to 88 years) who underwent elective endovascular aneurysm repair between June 2016 and September 2021 were retrospectively analyzed. According to the proximal infrarenal aortic neck diameter, the patients were divided into two groups: Group 1 (&lt;25 mm; normal aortic neck) and Group 2 (≥25 mm; pre-aneurysmatic aortic neck). Patient characteristics, proximal infrarenal aortic neck diameter measurements with computed tomography angiography, and clinical outcomes were recorded. The primary endpoint was to assess post-endovascular aneurysm repair aortic neck dilatation, mortality, endoleaks, overall survival, type 1a endoleaks-free survival, and eventfree survival regarding the groups. Results: There was no statistically significant difference in early mortality (p=0.55) and type 1a endoleak incidence between the groups (p=0.55). In Group 1, the mean change in diameter A (proximal infrarenal level) was 2.89±1.74 mm (p=0.01), and it was 2.31±2.1 mm in diameter B (proximal pre-aneurysm-sac level) (p=0.01). The mean change in Group 2 was 2.8±3.4 mm for diameter A (p&lt;0.01) and 2.22±2.3 mm for diameter B (p&lt;0.01). Aortic neck dilatation rates were similar between the groups (p=0.82 for diameter A; p=0.78 for diameter B). The five-year survival, event-free survival, and type 1a endoleak-free survival were also similar (p=0.54, p=0.26, p=0.24, respectively). Conclusion: Our study results showed that patients with &lt;25 mm and ≥25-mm aortic neck diameters had similar mid-term results and aortic neck dilatation ratio. Endovascular aneurysm repair outcomes can be improved with careful patient and graft selection, and early intervention for complications.

Early outcomes of the Conformable endograft in severe neck angulation from the Triveneto Conformable Registry

ObjectiveThe study reports retrospective evaluation of early outcomes from a multicentric experience with the Excluder conformable endograft with active control system (CEXC Device) in the treatment of abdominal aortic aneurysms. Its design allows more flexibility, given by proximal unconnected stent rows and a bending wire within the delivery catheter enables control of proximal angulation. This study specifically focuses on the severe neck angulation (SNA) subgroup (≥60°). MethodsAll patients treated with CEXC Device in nine vascular surgery centers of Triveneto area (Northeast Italy) between January 2019 and July 2022 were enrolled prospectively and analyzed retrospectively. Demographic and aortic anatomical characteristics were evaluated. Endovascular aneurysm repair in SNA were selected for analysis. Major investigated outcomes were technical success, endoleaks, morbidity, mortality, and reinterventions at 30 days and during follow-up. Endograft migration and postoperative aortic neck angulation changes were also analyzed. ResultsA total of 129 patients were enrolled. An infrarenal angle of ≥60° was observed in 56 patients (43%) (SNA group) and their data analyzed. The mean patient age was 78.9 ± 5.9 years and median abdominal aortic aneurysm diameter 59 mm (range, 45-94 mm). Median aortic infrarenal neck length, angulation and diameter were 22 mm (range, 13-58 mm), 77° (range, 60°-150°), and 22.0 ± 3.5 mm respectively. Analysis revealed a technical success rate of 100% and perioperative major complication rate of 1.7%. Intraoperative and perioperative morbidity and mortality rates were 3.5% (one buttock claudication and one inguinal surgical cutdown) and 0%, respectively. No perioperative type I endoleaks were observed. The median follow-up was 13 months (range, 1-40 months). Five patients died during follow-up from aneurysm-unrelated causes. Two reinterventions occurred (3.5%): one conversion for a type IA endoleak and one sac embolization for a type II endoleak. Aneurysm sac shrinkage was observed in 15 patients (26%) and aneurysm stability in 35 patients (62%), respectively. Estimated freedom from reinterventions at 24 months was 92%. Aortic neck median postoperative angulation was 75° (range, 45°-139°). ConclusionsThe Triveneto Conformable Registry shows good early results of the CEXC device in severely angulated aortic infrarenal necks. These data need confirmation on longer follow-up and a wider cohort of patients to further increase endovascular aneurysm repair eligibility in SNA.

Suprarenal vs Infrarenal Graft Fixation Does Not Affect Outcomes After Endovascular Aortic Aneurysm Repair in Patients with Favorable Neck Anatomy

The decision to choose an endograft with or without suprarenal fixation for the treatment of aortic aneurysm remains highly debatable. Literature to date has focused on quantifying the risk of suprarenal graft fixation on renal function. This study aims to assess the effect of graft fixation on renal function as well as other intra- and postoperative outcomes. The Vascular Quality Initiative was queried from 2012 to 2022 to identify patients undergoing EVAR for infrarenal aortic aneurysms. Patients with hostile neck were excluded (aortic neck diameter >28 mm, neck length <15, angulation >60°). Patients were stratified on suprarenal vs infrarenal graft fixation. Primary outcomes were postoperative complications and aortic reintervention. Of the patients identified, 2357 (21.1%) and 8837 (78.9%) underwent suprarenal vs infrarenal graft fixation, respectively. Patients who underwent suprarenal graft fixation were more likely to be on an aspirin (68.1% vs 63.5%; P < .001) or a beta-blocker (52.1% vs 49.5%; P = .026). Otherwise, comorbidities and medications were similar between the cohorts (Table). Suprarenal grafts were more likely to be performed electively (90.5% vs 88.2%; P = .002). On completion angiogram, suprarenal, as compared to infrarenal, graft fixation was associated with endoleak (27.8% vs 21.8%; P < .001), but there was no difference in type Ia endoleaks (2.0% vs 2.1%; P = .760). At 1 year, there was a higher reintervention rate among the suprarenal cohort (5.2% vs 3.5%; P = .003); however, there was no difference in interventions for type Ia endoleak. There was a higher rate of renal artery coverage in the suprarenal cohort (2.8% vs 1.8%; P = .001), but no difference in rate of re-intervention for renal artery stenosis/occlusion (0.4% vs 0.2%; P = .170) or difference in creatinine elevation at follow-up (0.08 ± 0.67 vs 0.06 ± 0.51; P = .43). Patients who underwent EVAR with suprarenal graft fixation were more likely to have an endoleak on completion angiogram, however, there was no difference in type Ia endoleak. As such, higher rates of reintervention seen in the suprarenal graft fixation group was not found to be driven by proximal leaks. Although renal artery encroachment and/or coverage was more commonly observed after suprarenal graft fixation, there was no significant difference in creatinine elevation, reintervention rates for renal artery occlusion or dialysis dependence. Given the equivalent outcomes, surgeon preference and experience should dictate decision to use suprarenal or infrarenal fixation in patients with favorable neck anatomy.TableDemographics and comorbiditiesVariableInfrarenal graftSuprarenal graftP valueMale7320 (82.8)1941 (82.4).581Age, years72.9 ± 8.873.8 ± 8.8.859Current smoker2725 (30.8)683 (29).082Hypertension7226 (81.8)1912 (81.1).469Diabetes1769 (20)465 (19.7).753Coronary artery disease2569 (29.1)689 (29.3).870Congestive heart failure1053 (11.9)262 (11.1).286Hemodialysis76 (0.9)15 (0.6).283Preoperative aspirin5605 (63.5)1604 (68.1)<.001Preoperative P2Y inhibitor1145 (13)288 (12.2).344Preoperative statin6214 (70.3)1704 (72.4).052Preoperative beta-blocker4373 (49.5)1223 (52.1).026Preoperative angiotensin-converting enzyme inhibitor4047 (45.8)1070 (45.5).744Preoperative anticoagulant1250 (14.1)312 (13.2).262Values are mean ± standard deviation or number (%). Open table in a new tab

Anatomical feasibility of fenestrated stent graft to treat complex abdominal aortic aneurysms from a Korean single institute database.

This study aims to investigate the feasibility of Zenith Fenestrated AAA Endovascular Graft (Z-FEN, Cook Medical) from a single Korean institution database by evaluating the vascular anatomy of Korean abdominal aortic aneurysm (AAA) patients with hostile aortic neck. This is a retrospective study on patients with AAA who underwent endovascular aortic repair (EVAR) and open surgery repair between January 2012 and December 2021 (n = 211). The anatomic characteristics of the aortic neck were evaluated using 3-dimensional reconstructed computed tomographic scans. For the juxtarenal AAA patients (n = 39), feasibility of fenestrated stent graft was evaluated under the protocol of fenestrated EVAR. For those who were not suitable for the application of Z-FEN, the reasons for unsuitability were analyzed. Among 211 AAA patients, 108 patients (51.2%) had complex aortic neck, and 39 (18.5%) had insufficient aortic neck length (<15 mm) for conventional EVAR. Of the 39 patients with juxtarenal AAAs, 13 (33.3%) were determined feasible for Z-FEN. Twenty-six patients (66.7%) were noncandidate for Z-FEN due to severe neck angulation, short aortic neck length, inadequate iliac artery anatomy, large aortic neck diameter, and severe calcification and thrombosis. Proximal aortic neck length of the non-feasible group was significantly shorter than that of the feasible group (P = 0.002). Z-FEN was applicable to 33.3% of the juxtarenal AAA patients. As recent studies confirm, the effectiveness and safety of fenestrated EVAR, Z-FEN can be an option for AAA patients with short aortic neck.

Effect of Two Years of Doxycycline Treatment on Infrarenal Aortic Neck Diameter

Effect of Two Years of Doxycycline Treatment on Infrarenal Aortic Neck Diameter

One-year safety and effectiveness of the Alto abdominal stent graft in the ELEVATE IDE trial

ObjectiveThis study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the polymer based Endologix Alto Stent Graft System in treating abdominal aortic aneurysms (AAAs), with sealing 7 mm below the top of the fabric in aortic neck diameters from 16 to 30 mm. MethodsSeventy-five patients were treated with Alto devices between March 2017 and February 2018 in 16 centers in the United States for infrarenal AAAs (max diameter ≥5.0 cm in diameter or size increase by 0.5 cm in 6 months or diameter ≥1.5 times the adjacent normal aorta). Patients were followed for 30 days, 6 months, and 1 year by clinical evaluation and computed tomography and abdominal x-ray imaging. Treatment success was defined as technical success and freedom from AAA enlargement, migration, type I or III endoleak, AAA rupture or surgical conversion, stent graft stenosis, occlusion, kink, thromboembolic events, and stent fracture attributable to the device requiring secondary intervention through 12 months. Preoperative characteristics, perioperative variables, follow-up clinical evaluations, and radiographic examination results through the first 1 year were analyzed. ResultsThe mean patient age was 73 years, with 93% of patients being male. The 30-day major adverse event rate was 5.3%. At 1 year, the primary endpoint was met with a treatment success rate of 96.7%. Through 1-year post-treatment, all-cause mortality was 4.0%. No AAA-related mortality occurred. AAA enlargement was 1.6%, type I endoleak rate was 1.4%, with 100% freedom from type III endoleaks, device migration, device fracture, stent occlusion, or AAA rupture. The device-related secondary intervention rate was 2.7%. ConclusionsThis prospective study demonstrates the Endologix Alto is safe and effective in treating AAAs with appropriate anatomy at 1 year. The safety endpoint is met by a 5.3% 30-day major adverse event rate, whereas the effectiveness endpoint is met by a treatment success rate of 96%.

Late Neck Related Adverse Events are Rare Among Patients with Wide Aortic Neck Undergoing Endovascular Aneurysm Repair with the Ovation Endograft

Patients with wide aortic necks undergoing Endovascular Aneurysm Repair (EVAR) have been shown to be at a higher risk for neck-related complications. We aim to examine outcomes of EVAR with an endograft exerting minimal outward pressure (Ovation-Endologix) in patients with a large baseline neck diameter. We performed a retrospective single center study, including consecutive patients undergoing EVAR with the Ovation system from May 2011 to April 2021. Patients were divided in Groups 1 and 2 if the 20, 23, 26, 29 mm or the 34mm proximal diameter main body was used, respectively. According to the instructions for use of the device, for neck diameters 27-30mm the 34mm main body is required. Primary endpoint was rate of neckrelated complications during follow-up, (type Ia endoleak, migration >10mm and neck-related re-interventions) and rate of aortic neck dilatation (AND). AND was determined based on multiple aortic neck diameters that were recorded and compared between the 1-month computed tomography angiography (CTA) after EVAR and the last available follow-up CTA.Secondary endpoints were peri-procedural and follow-up outcomes such as endoleaks, reinterventions and overall mortality. In total 281 patients were included, 222 in Group 1 and 59 in Group 2. Patients in Group 2 presented significantly shorter neck length, higher neck angulation and more common reversed tapered configuration. Median follow-up was 36months (Range: 6-106). Early and late type Ia endoleak was observed in 4 and 2 patients in each group, respectively (P=0.063 and P=0.195, respectively). Distal migration was observed in 2 patients in Group 2 and AND was recorded in 2 patients in each group (P=0.195). Freedom from the primary endpoint was estimated at 98%, 94%, 94% at 12-, 36-, 60-months for Group 1 and at 98%, 95%, 86% for Group 2 (P-Value 0.266). Probability of survival was 95%, 86%, 75% at 12-, 36-, 60-months for Group 1 and 83%, 77%, 72% for Group 2 (P-Value 0.226).Multivariate regression analysis identified neither Group 1 versus Group 2 nor absolute value of aortic neck diameter as significant predictors of neck-related adverse events. Neck diameters did not display significant differences over time in any of the levels evaluated. EVAR with the Ovation endograft results in low rates of late neck related complications which is also true for patients with wide baseline aortic necks.

Supra- and Infra-Renal Aortic Neck Diameter Increase after Endovascular Repair of a Ruptured Abdominal Aortic Aneurysm.

Hypovolemia-induced hypotension may lead to an aortic diameter decrease in patients with a ruptured abdominal aortic aneurysm (rAAA). This study investigates the changes in supra- and infra-renal aortic neck diameters before and after endovascular aortic aneurysm repair (EVAR) for rAAA and the possible association with endograft apposition. A retrospective cohort study was conducted including 74 patients treated between 2010 and 2019 in two large European vascular centers. Outer-to-outer wall diameters were measured at +40, +10, 0, −10, and −20 mm relative to the lowest renal artery baseline on the last pre- and first post-EVAR computed tomography angiography (CTA) scan in a vascular workstation. Endograft apposition was determined on the first post-EVAR CTA scan. The post-operative diameter was significantly (p < 0.001) larger than the preoperative diameter at all aortic levels. The aortic diameter at +40 mm (supra-renal) and −10 mm (infra-renal) increased by 6.2 ± 7.3% and 12.6 ± 9.8%, respectively. The aortic diameter at +40 mm increased significantly more in patients with low preoperative systolic blood pressure (<90 mmHg; p = 0.005). A shorter apposition length was associated with a higher aortic diameter increase (R = −0.255; p = 0.032). Hypovolemic-induced hypotension results in a significant decrease in the aortic diameter in patients with an rAAA, which should be taken into account when oversizing the endograft.

Abdominal aortic aneurysm neck dilatation and sac remodeling in fenestrated compared to standard endovascular aortic repair.

Contemporary commercially available endovascular devices for the treatment of abdominal aortic aneurysm (AAA) include standard endovascular aortic repair (sEVAR) or fenestrated EVAR (fEVAR) endografts. However, aortic neck dilatation (AND) can occur in nearly 25% of patients following EVAR, resulting in loss of proximal seal with risk of aortic rupture. AND has not been well characterized in fEVAR, and direct comparisons studying AND between fEVAR and sEVAR have not been performed. This study aims to analyze AND in the infrarenal and suprarenal aortic segments, including seal zone, and quantify sac regression following fEVAR implantation compared to sEVAR. A retrospective review of prospectively collected data on 20 consecutive fEVAR patients (Cook Zenith® Fenestrated) and 20 sEVAR (Cook Zenith®) patients was performed. Demographic data, anatomic characteristics, procedural details, and clinical outcome were analyzed. Pre-operative, post-operative (1month), and longest follow-up CT scan at an average of 29.3months for fEVAR and 29.8months for sEVAR were analyzed using a dedicated 3D workstation (iNtuition, TeraRecon Inc, Foster City, California). Abdominal aortic aneurysm neck diameter was measured in 5mm increments, ranging from 20mm above to 20mm below the lowest renal artery. Sub-analysis comparing the fEVAR to the sEVAR group at 12months and at greater than 30months was performed. Standard statistical analysis was done. Demographic characteristics did not differ significantly between the two cohorts. The fEVAR group had a larger mean aortic diameter at the lowest renal artery, shorter infrarenal aortic neck length, increased prevalence of nonparallel neck shape, and longer AAA length. On follow-up imaging, the suprarenal aortic segment dilated significantly more at all locations in the fEVAR cohort, whereas the infrarenal aortic neck segment dilated significantly less compared to the sEVAR group. Compared to the sEVAR cohort, the fEVAR patients demonstrated significantly greater positive sac remodeling as evident by more sac diameter regression, and elongation of distance measured from the celiac axis to the most cephalad margin of the sac. Device migration, endoleak occurrence, re-intervention rate, and mortalities were similar in both groups. Compared to sEVAR, patients undergoing fEVAR had greater extent of suprarenal AND, consistent with a more diseased native proximal aorta. However, the infrarenal neck, which is shorter and also more diseased in fEVAR patients, appears more stable in the post-operative period as compared to sEVAR. Moreover, the fEVAR cohort had significantly greater sac shrinkage and improved aortic remodeling. The suprarenal seal zone in fEVAR may result in a previously undescribed increased level of protection against infrarenal neck dilatation. We hypothesize that the resultant decreased endotension conferred by better seal zone may be responsible for a more dramatic sac shrinkage in fEVAR.

Effect of Stent-Graft Active Fixation and Oversizing on Aortic Neck Dilation After Endovascular Aneurysm Exclusion For Infrarenal Aortic Aneurysm

IntroductionAortic neck dilation post endovascular aneurysm repair (EVAR) has been implicated in the long-term development of endoleak and the subsequent re-intervention. Optimal endograft sizing is a vital aspect to successful repair. This study looked at percentage of graft oversizing as well as type of fixation on aortic neck dilation. MethodsWe retrospectively evaluated all EVARs completed at Loyola's University from 2006 to 2015 after IRB approval. Patients without follow-up scans within a year were excluded. We collected demographics, comorbidities, graft type, size, aortic neck diameter, maximum sac size diameters from the pre-operative and follow-up scans. We reviewed and collected data on 432 patients but analyzed 154. We measured the largest aortic diameter on axial images 1 cm above and 1 cm below the lowest renal artery. Change in supra and infrarenal aortic measurements were evaluated by calculating the mm difference from each scan compared to the pre-operative scan. Linear mixed effects models were used to estimate patients’ mean differences over time. ResultsWe compared three groups of neck fixation grafts. Those with active suprarenal fixation had a significant change in suprarenal aortic diameter at four-year follow-up (1.86 mm, CI:0.65–3.06), compared to those with active infrarenal (0.22 mm, CI: -0.67 to -1.11) or passive suprarenal fixation (1.52 mm, CI: -0.11 to -3.15) (Fig. 1). Those with active suprarenal fixation were the only ones to have significant increase in suprarenal aortic diameter (P = 0.0026). Degree of oversizing was also divided into three groups. Oversizing by <10% had less impact on the suprarenal aorta than >15% oversizing at 4 years (0.41 mm, CI: -0.31 to -1.14 vs. 3.26 mm, CI: 1.63–4.88, P < 0.001) (Fig. 2). Oversizing had a more pronounced effect on the infrarenal aorta: 3.01 mm, CI: 2.18–3.83; 5.95 mm, CI: 3.26–8.64; and 5.05 mm, CI: 3.41–6.69 for <10%, 10–15%, and >15% oversizing at four years, respectively. ConclusionStent-grafts with active fixation below the renal arteries as well as oversizing by <10% seem to have the least effect on aortic neck dilation over time. These factors should be considered when performing EVARs, as aortic neck dilation could lead to endoleak and need for further intervention. Further research defining the optimal stent-graft type, self-expanding versus balloon expandable, type of fixation and degree of oversizing.

Endograft apposition and infrarenal neck enlargement after endovascular aortic aneurysm repair

Sufficient apposition and oversizing of the endograft in the aortic neck are both essential for durable endovascular aneurysm repair (EVAR). These measures are however not regularly stated on post-EVAR computed tomography angiography (CTA) scan reports. In this study endograft apposition and neck enlargement (NE) after EVAR with an Endurant II(s) endograft were analyzed and associated with supra- and infrarenal aortic neck morphology. In 97 consecutive elective patients, the aortic neck morphology was measured on the pre-EVAR CTA scan on a 3mensio vascular workstation. The distance between the lowest renal artery and the proximal edge of the fabric (shortest fabric distance, SFD), and the shortest length of circumferential apposition between endograft and aortic wall (shortest apposition length, SAL) were determined on the early post-EVAR CTA scan. NE, defined as the aortic diameter change between pre- and post-EVAR CTA scan, was determined at eight levels: +40, +30, +20, +15, +10, 0, -5 and -10 mm relative to the lowest renal artery baseline. The aortic neck diameter and preoperative oversizing were correlated to NE with the Pearson correlation coefficient. The effective post-EVAR endograft oversizing is calculated from the nominal endograft diameter and the post-EVAR neck diameter where the endograft is circumferentially apposed. The median time (interquartile range, IQR) between the EVAR procedure and the pre- and post-EVAR CTA scan was 40 (25, 71) days and 36 (30, 46) days, respectively. The Endurant II(s) endograft was deployed with a median (IQR) SFD of 1.0 (0.0, 3.0) mm. The SAL was <10 mm in 9% of patients and significantly influenced by the pre-EVAR aortic neck length (P=0.001), hostile neck shape (P=0.017), and maximum curvature at the suprarenal aorta (P=0.039). The median (interquartile range) SAL was 21.0 (15.0, 27.0) mm with a median (IQR) pre-EVAR infrarenal neck length of 23.5 (13.0, 34.8) mm. The median (IQR) difference between the SAL and neck length was -5.0 (-12.0, 2.8) mm. Significant (P<0.001) NE of 1.7 (0.9, 2.5) mm was observed 5 mm below the renal artery baseline, which resulted in an effective post-EVAR endograft oversizing <10% in 43% of the patients. No correlation was found between NE and aortic neck diameter or preoperative oversizing. Circumferential apposition between an endograft and the infrarenal aortic neck, SAL, and NE can be derived from standard postoperative CT scans. These variables provide essential information about the post-procedural endograft and aortic neck morphology regardless of the preoperative measurements. Patients with SAL<10 mm or effective oversizing <10% due to NE may benefit from intensified follow-up, but clinical consequences of SAL and NE should be evaluated in future longitudinal studies with longer term follow-up.

The retroperitoneal approach for contemporary open abdominal aortic aneurysm surgery: The anatomical reasoning.

In current practice, the place of open surgery in managing abdominal aortic aneurysm is a contentious issue. The principal reason being greater applications of endovascular techniques treating increasingly complicated aortic disease. Development of branched and fenestrated devices enabled this, with numbers increasing annually. This meant a good risk patient with a long infrarenal aortic neck and normal diameter non-tortuous iliac arteries may be suitable for both endovascular and open techniques. However, indications for open surgery are becoming increasingly unclear nowadays due to short-term gains in morbidity and mortality. Exact aortic anatomical morphologies optimum for open or endovascular techniques remains unclear. As graft technology evolves, possibilities for endovascular options are expanding. Currently, establishing optimum treatment plans for complicated abdominal aortic aneurysm (little or no infrarenal neck) is difficult without considering general fitness of the patient. Hence, two sets of possible postoperative complications and follow-up protocols must be explained to patients before either approach. Complicating matters is the optimum surgical approach used for any open repair. The standard approach for open abdominal aortic aneurysm surgery has been transperitoneal as this provides excellent access to the infrarenal aorta and iliac arteries. However, although less commonly used, the retroperitoneal approach has advantages particularly when location of proximal aortic disease indicates suprarenal clamp might be optimum. This paper scrutinises benefits of the retroperitoneal approach performed purely for anatomical reasons where stent graft may be considered complicated. Also, long-term outcomes are examined in terms of endo-leak and subsequent development of true and false aneurysm following both endovascular and open repair.

Risk Factors, Dynamics, and Clinical Consequences of Aortic Neck Dilatation after Standard Endovascular Aneurysm Repair

Aortic neck dilatation (AND) occurs after endovascular aneurysm repair (EVAR) with self expanding stent grafts (SESs). Whether it continues, ultimately exceeding the endograft diameter leading to abdominal aortic aneurysm (AAA) rupture, remains uncertain. Dynamics, risk factors, and clinical relevance of AND were investigated after EVAR with standard SESs. All intact EVAR patients treated from 2000 to 2015 at a tertiary institution were included. Demographic, anatomical, and device related characteristics were investigated as risk factors for AND. Outer to outer diameters were measured at a single standardised aortic level on reconstructed computed tomography (CT) images. A total of 460 patients were included (median follow up 5.2 years, interquartile range [IQR] 3.0, 7.7 years; CT imaging follow up 3.3 years, IQR 1.3, 5.4). Baseline neck diameter was 24 mm (IQR 22, 26) and increased 11.1% (IQR 1.5%, 21.9%) at last CT imaging. Endograft oversizing was 20.0% (IQR 13.6, 28.0). AND was greater during the first year (5.2% [IQR 0, 11.7]) decreasing subsequently (two to four years to 1.4%/year [IQR 0.0, 4.5%], p ≤ .001) and was associated with suprarenal fixation endografts (t value = 7.9, p < .001) and oversizing (t value = 4.4, p < .001). AND exceeding the endograft was 3.5% (95% CI 2.2% – 4.8%) and 14.4% (95% CI 11.0% – 17.8%) at five and eight years, respectively. Excessive AND was associated with baseline neck diameter (OR 1.2/mm, 95% CI 1.05 – 1.41) while the Excluder endograft had a protective effect (OR 0.15, 95% CI 0.04 – 0.58). Excessive AND was associated with type 1A endoleak (HR 3.3, 95% CI 1.1 – 9.7) and endograft migration > 5 mm (HR 3.1, 95% CI 1.4 – 6.9). AND after EVAR with SES is associated with endograft oversizing and radial force but decelerates after the first post-operative year. Baseline aortic neck diameter and suprarenal stent bearing endografts were associated with an increased risk of AND beyond nominal stent graft diameter. However, it remains unclear whether patient selection, differences in endograft radial force or the suprarenal stent are accountable for this difference.

A Five-Year Computed Tomography Follow-up Study of Proximal Aortic Neck Dilatation After Endovascular Aortic Repair Using Four Contemporary Types of Endograft.

This study analysed the progression of proximal aortic neck diameter in patients with asymptomatic abdominal aortic aneurysms, treated by endovascular aortic repair using four different, contemporary types of endograft. This is a retrospective study of four cohorts of 30 patients presenting with asymptomatic abdominal aortic aneurysms and treated with endovascular aortic repair using four different types of contemporary endografts, namely Endurant® (Medtronic), Excluder® (W.L. Gore), Zenith® (Cook Medical) and Ovation® (Endologix) endografts. Patients' demographics and aortic aneurysm measurements, including suprarenal aortic, proximal infrarenal neck and maximum aortic aneurysmal diameter, were gathered from the patients' electronic medical records, pre- and post-interventional computed tomography studies, respectively. Diameter measurements were modelled as a function of endograft type; an interaction test was used to test whether the evolutions over time were different between the four types of endograft. Suprarenal aortic diameter increased over time (P = 0.0235) and maximum aortic aneurysm diameter decreased over time (P = 0.0008) in the four types of endograft. The progressive increase in proximal neck diameter from preoperative baseline up to five years of follow-up was 1.20mm for Endurant (P = 0.0054), 1.72mm for Ovation (P = 0.0006), 1.14mm for Excluder (P = 0.0102) and 2.83mm for Zenith (P < 0.0001), respectively. Five patients (4%) presented with a late-type 1a endoleak: Endurant (n = 1); Ovation (n = 2) and Zenith (n = 2). All endografts were associated with a progressive dilatation of the proximal aortic neck over a time interval of five years and may be associated with late-type 1a endoleak.

Funnel technique for wide infrarenal aneurysm neck with Lifetech Ankura™ Stent Graft System.

Background In this study, we present our mid-term results in patients undergoing treatment with the funnel technique and describe technical issues for this bailout technique in extra-wide infrarenal necks. Methods Between January 2018 and June 2020, a total of seven male, symptomatic patients (median: 74.5 years; range, 64 to 84 years) who had comorbidities and were in the American Society for Anesthesiologists Class IV and treated by the funnel technique in an endovascular fashion were included. Pre- and post-procedural data of the patients, early mortality and technical success rates were evaluated. Results There was no early mortality. Technical success rate was 100%. There was no type I or III endoleaks at the completion angiography. All patients were discharged without any problem on the second or third day of the procedure. The median follow-up was 13 (range, 6 to 28) months. The aneurysm sac shrinkage was achieved in all patients over six months of follow up. During the follow-up period, no proximal endoleak or infrarenal aortic neck diameter enlargement was found. Conclusion Based on our limited experience, the funnel technique may be considered more than a bailout procedure under special circumstances.

Risk Factors, Dynamics, and Clinical Consequences of Aortic Neck Dilatation after Standard Endovascular Aneurysm Repair

Aortic neck dilatation (AND) occurs after endovascular aneurysm repair (EVAR) with self expanding stent grafts (SESs). Whether it continues, ultimately exceeding the endograft diameter leading to abdominal aortic aneurysm (AAA) rupture, remains uncertain. Dynamics, risk factors, and clinical relevance of AND were investigated after EVAR with standard SESs. All intact EVAR patients treated from 2000 to 2015 at a tertiary institution were included. Demographic, anatomical, and device related characteristics were investigated as risk factors for AND. Outer to outer diameters were measured at a single standardised aortic level on reconstructed computed tomography (CT) images. A total of 460 patients were included (median follow up 5.2 years, interquartile range [IQR] 3.0, 7.7 years; CT imaging follow up 3.3 years, IQR 1.3, 5.4). Baseline neck diameter was 24 mm (IQR 22, 26) and increased 11.1% (IQR 1.5%, 21.9%) at last CT imaging. Endograft oversizing was 20.0% (IQR 13.6, 28.0). AND was greater during the first year (5.2% [IQR 0, 11.7]) decreasing subsequently (two to four years to 1.4%/year [IQR 0.0, 4.5%], p ≤ .001) and was associated with suprarenal fixation endografts (t value= 7.9, p < .001) and oversizing (t value= 4.4, p < .001). AND exceeding the endograft was 3.5% (95% CI 2.2% - 4.8%) and 14.4% (95% CI 11.0% - 17.8%) at five and eight years, respectively. Excessive AND was associated with baseline neck diameter (OR 1.2/mm, 95% CI 1.05 - 1.41) while the Excluder endograft had a protective effect (OR 0.15, 95% CI 0.04 - 0.58). Excessive AND was associated with type 1A endoleak (HR 3.3, 95% CI 1.1 - 9.7) and endograft migration > 5 mm (HR 3.1, 95% CI 1.4 - 6.9). AND after EVAR with SES is associated with endograft oversizing and radial force but decelerates after the first post-operative year. Baseline aortic neck diameter and suprarenal stent bearing endografts were associated with an increased risk of AND beyond nominal stent graft diameter. However, it remains unclear whether patient selection, differences in endograft radial force or the suprarenal stent are accountable for this difference.