Distal Aortic Diameter Research Articles

Intravascular Ultrasound May Not Impact Graft Sizing in Endovascular Repair of Blunt Thoracic Aortic Injury.

Thoracic endovascular aortic repair (TEVAR) is the preferred treatment for severe blunt thoracic aortic injuries (BTAI). Successful outcomes rely on accurate endograft sizing, but initial imaging may underestimate aortic diameters. This study examines the impact of intravascular ultrasound (IVUS) on endograft sizing and clinical outcomes in BTAI patients. A prospectively collected multi-institutional dataset from the Aortic Trauma Foundation was analyzed. Patients with BTAI undergoing TEVAR with IVUS were compared to patients who underwent TEVAR alone. Demographics and operative variables were compared, focusing on IVUS effects on endograft sizing by examining maximal proximal and distal aortic diameter on initial CT imaging compared to the graft diameters used during TEVAR. 293 patients underwent TEVAR for BTAI with IVUS utilized in 124 cases (42.3%). The average graft size in the IVUS and non-IVUS groups were similar proximally (26.91 ± 4.3mm IVUS vs 27.77 ± 4.7mm non-IVUS, P = 0.116) and distally (25.96 ± 4.7mm IVUS vs 26.51 ± 4.7mm non-IVUS). IVUS did not impact the difference between graft size and initial CT measurements proximally (4.32 ± 4.8mm IVUS vs 4.23 ± 3.9mm non-IVUS, P = 0.859) or distally (4.17 ± 5.9mm IVUS vs 4.50 ± 4.3mm non-IVUS, P = 0.606). Although delayed hemorrhagic and ischemic stroke occurred less frequently in IVUS patients (0.8% IVUS vs 7.1% non- IVUS, P = 0.024), in-hospital mortality was similar between groups (5.6% IVUS vs 7.7% non-IVUS, P = 0.581). IVUS is not associated with significant changes in endograft sizing compared to sizing based on CT scan alone in BTAI patients. IVUS was not associated with differences in mortality but was associated with a decrease in delayed hemorrhagic and ischemic stroke. Routine IVUS in BTAI patients may not be necessary for accurate sizing, but there may be a relationship between IVUS and stroke.

Distal Repair After Total Aortic Arch Replacement With Frozen Elephant Trunk in Patients With Chronic Multilevel Thoracic Aortic Disease

To examine the management of distal aortic disease after total arch replacement with the frozen elephant trunk (TAR+ FET) in patients with chronic thoracic aortic disease. Two centre retrospective study of consecutive patients treated between January 2010 and December 2019. The primary endpoint was 30 day or in hospital death. The secondary endpoint was midterm survival. Data are presented as median (interquartile range [IQR]). The χ2 or Fisher's exact test was used as appropriate. Estimated survival (standard error) was assessed by calculating the Kaplan-Meier product limit estimator with right censoring of survival data. A p value of < .050 was considered statistically significant. STROBE guidelines were followed. A total of 158 patients (72 men; median age 70 years, IQR 64, 75; median distal aortic diameter 58 mm, IQR 46, 68; 127 aneurysmal disease, 31 chronic dissection) underwent TAR+ FET. The peri-operative mortality rate was 10.1% (9/107 elective, 7/51 non-elective). Of 74 (46.8%) patients with a primary distal seal, seven (9.5%) died peri-operatively, the distal seal was maintained during follow up in 51, nine underwent late distal repair (two planned, seven unplanned; one open, eight endovascular; one peri-operative death) with a median interval to unplanned repair of 777 days (IQR 462, 1480), and seven with loss of seal had no intervention. Distal seal failed in 2/28 (7%) patients with a distal seal length > 30 mm and device oversizing > 10%, compared with 12/39 (31%) patients who did not meet these criteria (p= .031). In 84 patients without a primary distal seal, nine (10.7%) died peri-operatively, the distal aorta remained below the size threshold for repair during follow up in 12 patients, 44 had distal repair (median aortic diameter 64 mm, IQR 60, 75; eight open, one hybrid, 35 endovascular repairs; no deaths) at a median of 256 days (IQR 135, 740), and 19 did not have distal repair at the end of the follow up period: six died before planned repair at a median interval of 115 days (IQR 85, 120); eight were considered unfit; one was assessed as fit but declined; and four patients were awaiting assessment. Median follow up was 46 months (IQR 26, 75): no patients were lost to follow up. Estimated ± standard error five year survival was 61.5 ± 4.1%: elective 70.6 ± 4.7%, non-elective 43.2 ± 7.2%. TAR+ FET achieved primary distal seal in 47% of patients, but late failure occurred in 21%. Distal repair was ultimately indicated in 84% of survivors without a primary distal seal and of these 70% underwent repair, almost 10% died before planned repair, and 13% were considered unfit. Earlier distal endovascular repair and better assessment of patient fitness may improve midterm outcomes.

Surgical Treatment for Branched Endograft Thrombosis of the Abdominal Aorta

Introduction. Endovascular intervention was firstly introduced for repairing aortic aneurysms in the early 1990s. The greatest advantage of endovascular aneurysm repair (EVAR) is its minimally-invasive character, thus implying shorter post-operative period. The operative mortality rate comprises 3.3 % (95 % CI 2.9–3.6); however, according to recent studies, the rate has declined to 1.4 % due to a rapid improvement in outcomes. According to the DREAM-trial, the incidence of a branched endograft thrombosis accounts for 6.4% within the first 30 days. The EVAR trial reports an incidence of 2.6% after the first year of follow-up. Stent bending and small distal aortic diameters (less than 20 mm) are believed to be the most common causes of endograft thrombosis.Aim. To identify the causes of complications following the abdominal aortic stent-graft repair and to determine the optimal treatment strategy.Materials and methods. The paper presents a case of 71-year-old patient with late complication after endovascular abdominal aortic repair of an infrarenal aortic aneurysm. The patient was admitted to the hospital on January 05, 2020 as an emergency due to the pain in the left lower limb. On December 03, 2019 the patient underwent endovascular abdominal aortic repair. Angiography of January 06, 2020 revealed thrombosis of the left branch of the stent graft. Thrombectomy of the brunched left stent graft, left iliac artery and balloon dilatation of the brunched left stent-graft were performed.Results and discussion. Endovascular abdominal aortic repair stands as the first choice for patients with appropriate aortic anatomy and those with significant comorbidity. Despite the significant progress in endovascular abdominal aortic repairing, the EVAR procedure is followed by a nearly fivefold increase in the 30-day reintervention rate as compared to open surgery which comprises 9.8 % according to the EVAR-I, and 18 %, according to the EVAR-II trials.Conclusion. Our multidisciplinary team consisted of vascular and endovascular surgeons managed to perform hybrid surgery, thus eliminating the EVAR-associated complication together with its cause.

Fate of the distal aorta following root replacement in Marfan syndrome: a propensity score matched study.

The aortic root is the most frequent segment involved in Marfan syndrome. However, Marfan syndrome is a systemic hereditary connective tissue disorder, and knowledge regarding the outcomes of the native distal aorta after prophylactic aortic root surgery is limited. From April 2010 to December 2020, 226 patients with Marfan syndrome and 1,200 patients without Marfan syndrome who underwent Bentall procedures were included in this study. By propensity score matching, 134 patients were assigned to each group. Clinical manifestations and follow-up data were acquired from hospital records and telephone contact. The cumulative incidence of aortic events was estimated in Marfan and non-Marfan patients with death as a competing risk. Patients with and without Marfan syndrome had similar baseline characteristics after propensity score matching. Differences in the aortic root (62.25 ± 11.96 vs. 54.03 ± 13.76, P < .001) and ascending aorta (37.71 ± 9.86 vs. 48.16 ± 16.01, P < .001) remained after matching. No difference was observed in the frequency of aortic adverse events between the two groups (10.5% vs. 4.6%, P = 0.106). The cumulative incidence of aortic events was not different between Marfan and non-Marfan patients (15.03% ± 4.72% vs. 4.18% ± 2.06%, P = 0.147). Multivariate Cox regression indicated no significant impact of Marfan syndrome on distal aortic events (HR: 1.172, 95% CI: 0.263-5.230, P = 0.835). Descending and abdominal aortic diameter above normal at the initial procedure were associated with the risk of distal aortic events (HR: 20.735, P = .003, HR: 22.981, P = .002, respectively). New-onset events of the residual aorta in patients undergoing Bentall procedures between the Marfan and non-Marfan groups were not significantly different. Distal aortic diameter above normal at initial surgery was associated with a higher risk of adverse aortic events.

Longitudinal follow-up by MR angiography reveals progressive dilatation of the distal aorta after aortic root replacement in Marfan syndrome.

To define and compare growth rates of the distal aorta in Marfan patients with and without aortic root replacement using serial MR angiography (MRA). We retrospectively included 136 Marfan patients with a total of 645 MRAs who underwent a median of five MRAs (range: 2-13) at 1.5T and 3T in annual intervals. Of these, 41 patients (34.8 ± 12years) had undergone aortic root replacement. The remaining 95 patients (29.0 ± 17years) still had a native aorta and served as the control group. Thoracic aortic diameters were independently measured at eleven predefined levels. Estimated growth rates were calculated using a mixed effects model adjusted for sex, age, BMI, and medication. Marfan patients with aortic root replacement revealed the highest mean estimated growth rate in the proximal descending aorta (0.77mm/year, CI: 0.31-1.21). Mean growth rates at all levels of the distal thoracic aorta were significantly higher in patients with aortic root replacement (0.28-0.77mm/year) when compared to patients without aortic root replacement (0.03-0.07mm/year) (all p < 0.001). Antihypertensive medication, gender, and BMI had no significant impact on the distal aortic growth rates. Distal thoracic aortic diameters increase at a significantly higher rate in Marfan patients with aortic root replacement compared to Marfan patients without aortic root replacement. Further studies are warranted to investigate if the increased growth rate of the distal thoracic aorta after aortic root replacement is caused by altered hemodynamics due to the rigid aortic root graft or due to the general genetic disposition of post-operative Marfan patients. High growth rates of the distal aorta after aortic root replacement underline the need for careful life-long aortic imaging of Marfan patients after aortic root replacement. • Aortic growth rates in Marfan patients with aortic root replacement are highest in the mid-aortic arch, the proximal- and mid-descending aorta. • Growth rates of the distal thoracic aorta are significantly higher in Marfan patients with aortic root replacement compared to Marfan patients without aortic root replacement. • Antihypertensive medication, gender, and BMI have no significant impact on distal aortic growth rates in Marfan patients.

When even luck matters: a compendium of all possible complications during hybrid repair of a dissecting TAAA occurred in a single patient

Purpose. A 73-year-old woman, already submitted to repair of the ascending aorta and subsequently to aortic valve substitution in redo sternotomy, presented to our attention with a dissecting TAAA with a distal aortic arch diameter of 6 cm. Our goal was to offer this extremely fragile patient the least invasive surgical treatment as possible. Technique. We treated this patient in two stages. In the first stage we performed a carotid-carotid-subclavian bypass. In the second stage we performed a TEVAR in zone 1, extending from the brachiocephalic artery to the celiac trunk. Left subclavian artery was previously occluded with a plug. CSFD was not adopted by default. Conclusion. This patient reported some extremely rare and unexpected complications that brought us to report this case. Hybrid techniques represent an extremely appealing opportunity to treat fragile patients affected by complex aortic diseases with relatively little invasive strategies, however, serious complications can occur.

Early outcomes with a hybrid technique for repair of a non-A non-B aortic dissection

ObjectiveThis study reports the early outcomes of patients with acute non-A non-B aortic dissection that involved the aortic arch but not the ascending aorta. MethodsFrom January 2013 to December 2018, 825 patients presented with aortic dissection. Of these, 28 patients with non-A non-B dissection (classified as dissection extending into the aortic arch with entry between the left common carotid artery and the left subclavian arteries) underwent a novel hybrid surgery. Self modified stent-grafts (Micropart Corp, Shanghai, China) were implanted via median sternotomy. Clinical presentation, postoperative data, and early outcomes were recorded. ResultsAll patients underwent an emergency operation. There were no in-hospital mortalities, reexplorations for hemorrhage, reports of paraplegia, cerebral infarctions, endoleaks, or left subclavian artery occlusions. No blood products were required during or after the operations. During the early follow-up at 39.12 ± 15.04 months (6.0-74.0 months), 1 patient was lost to follow-up, and 1 patient died suddenly. Computed tomography angiography showed false lumen patency persisted in the aortic arch and descending aorta without any symptoms. The 6-month computed tomography angiography showed significantly smaller distal aortic arch diameters (31.94 ± 6.95 mm) and descending aorta diameters (34.84 ± 4.15 mm) than measured preoperatively (36.76 ± 4.15 mm and 37.31 ± 4.7 mm, respectively). No paraplegia, cerebral infarction, upper limb ischemia, or left subclavian artery ischemia events were reported. ConclusionsOur inclusion aortic arch technique is a safe, effective, and simple treatment for non-A non-B aortic dissections that can avoid endoleaks, requires no blood products, and has satisfactory early outcomes.

Preoperative distal aortic diameter is a significant predictor of late aorta-related events after endovascular repair for chronic type B aortic dissection.

Long-term therapeutic effects of thoracic endovascular aortic repair (TEVAR) for chronic type B aortic dissection remain controversial. This study aimed to evaluate the possible predictors of late aortic rupture and re-interventions after TEVAR. We retrospectively reviewed the operative outcomes of 40 patients who underwent TEVAR for chronic type B aortic dissection at Kyushu University Hospital. During a mean follow-up period of 39.2months, we assessed aortic morphology via computed tomography and then employed a multivariable Cox regression analysis in an attempt to identify the predictors of late aorta-related events. The early success rate of TEVAR was 100%. During the follow-up, however, three patients died from aortic rupture. Eight patients required aortic re-intervention, including thoraco-abdominal aortic graft replacement, repeated TEVAR, total arch replacement and EVAR. Multivariable Cox regression analysis revealed that the preoperative maximum distal aortic diameter was a significant predictor of late aorta-related events. The cutoff value of the distal aortic diameter was 40mm. Freedom from aorta-related events was 94.6% at 1year and 78.3% at 3years. The survival rate was not significantly different despite the re-intervention. TEVAR is an effective treatment for chronic type B dissection, with acceptable mid-term results. The preoperative distal aortic diameter is a significant risk factor for late aorta-related events. When the maximum distal aortic diameter is ≥ 40mm, a therapeutic strategy should be developed taking into consideration the possible need for aortic re-intervention.

In Situ Fenestration to Convert an Aorto-Uni-Iliac Into a Bifurcated Endograft

Introduction - Narrow distal aorta and severely calcified aorto-iliac occlusive disease (AOID) represent conditions at risk of failure during endovascular aortic repairs. In such situations, an aorto-uni-iliac repair associated with a crossover femoro-femoral bypass (CFFB) may be preferable. We here present the results of an in situ fenestration (ISF) technique that allows conversion of an aorto-uni-iliac endograft (AUIE) into a bifurcated repair. Methods - Between January 2014 and January 2017, 163 patients underwent standard EVAR in our department. Among them, 20 patients (12%) underwent ISF of AUIE. All were considered at high surgical risk. After AUIE deployment, ISF was performed through the contralateral common iliac artery with a transjugular intrahepatic access set. The fabric hole was enlarged with a cutting balloon, and kissing iliac covered stents were positioned to convert the AUIE into a bifurcated repair. Data was collected prospectively. Results are presented as median with range. Results - The series included 13 males (65%) and 7 females (35%), aged 77 year-old (range, 37-88). Distal aortic diameter was 13 mm (range, 9-17). CFFB was felt at risk for complication in all cases for various reasons (radiation therapy, corticosteroids, small external iliac arteries, calcified femoral arteries, obesity). Indication for ISF was (1) an abdominal aortic aneurysm (AAA) with a narrow distal aorta (<14mm), (2) bilateral severely calcified AOID and (3) ruptured AAA in 10 (50%), 8 (40%) and 2 (10%) patients, respectively. The punctured graft was made of Dacron in 14 cases (70%) and a PTFE in 6 cases (30%). Technical success was 90%. The two failures were patients who had prior iliac ligation. Fluoroscopy time was 28 minutes (range, 15-46) and 90 cc (range, 70-140) of contrast product were necessary. There was no death or systemic complication, especially no postoperative bleeding. Hospitalization duration was 6 days (2-14). With a follow-up of 12 months (range, 1-20), all repairs were patent on last CT-scan. No endoleak was observed at the ISF site. Conclusion - This technique represents another application of ISF. Although it remains an off-label technique, it provides a bifurcated repair in cases where it is usually considered at risk. ISF use in other aortic sites, such as the visceral aorta, remains to be evaluated.

Sleep apnea and the impact on cardiovascular risk in patients with Marfan syndrome.

BackgroundMarfan syndrome (MFS) is an inherited connective tissue disorder characterized by ectopia lentis, aortic root dilation and dissection and specific skeletal features. Obstructive sleep apnea (OSA) in MFS has been described earlier but the prevalence and its relation with the cardiovascular risk is still controversial. This study aimed to further investigate these aspects.MethodsIn this prospective longitudinal study, we performed an attended polysomnography in 40 MFS patients (60% women, 37 ± 12.8 years) and evaluated several cardiovascular parameters through echocardiography, resting electrocardiogram, 24 hr‐Holter monitoring and serum NT‐ProBNP measurements.ResultsWe found that OSA was present in 42.5% of the patients and that higher body mass index was the most important factor associated with the presence of OSA. We observed that overweight was present in 27.5% of the patients in the whole cohort and in 55.6% if >40 years. Furthermore, when evaluating the impact of OSA on the cardiovascular system, we observed that patients with OSA tended to have higher systolic blood pressure, larger distal aortic diameters and a higher prevalence of ventricular arrhythmia. These differences were, however, not significant after adjusting for confounders.ConclusionsOur study shows a high prevalence of OSA and a high prevalence of overweight in MFS patients. We found some trends between OSA and cardiovascular features but we could not establish a solid association. Our study, however might be underpowered, and a multicenter collaborative study could be very useful to answer some important open questions.

Off-Pump Plicating Ascending Aortoplasty With External Wrapping: Magnum in Parvo

Isolated, fusiform aneurysms, exclusively affecting the tubular portion of the ascending aorta, are rare. Surgical treatment aims to change their natural course, reducing individual and cumulative risks of rupture, dissection and death. Open tubular graft replacement still remains the procedure of choice, despite significant risks. In permanent pursuit for optimal, alternative surgical strategy in high-risk patients, less invasive and off-pump plicating ascending aortoplasty with modified external Dacron graft wrapping seems to be a reliable choice. Two (2) consecutive patients were operated on. The same preoperative calculations and slightly different operative techniques were applied regarding surgical exposure and wrapping graft orientation. Immediate and late follow-up (5 years) results were compared. Absolute and indexed target ascending aortic diameters remained acceptable (<2.1cm/m2 considered the upper normal range for adults). There were no significant changes in proximal and distal aortic diameters. Ascending aortic silhouette on contrast enhanced multi-detector CT was better with Dacron wrapping graft tailored to have its grooves in the longitudinal direction. Upper mini-sternotomy was quite appropriate for this procedure, from a surgical point of view, and was safe for the patient. Careful patient selection and using the current model of preoperative calculations and surgical technique resulted in acceptable and stable ascending aortoplasty in high-risk patients 5 years after surgery.

RF25 HYBRID PALLIATION ALLOWS THE HYPOPLASTIC LEFT VENTRICLE FOR A CHANCE OF BIVENTRICULAR REPAIR: ECHO-SURVEILLANCE ON LEFT HEART GROWTH

Background: Several parameters of LV adequacy are available, however, it is now clear that the timing of decision plays a crucial role in the fate of the borderline LV, because the longer the ventricle is allowed to grow, the higher the probability to achieve functional independence. Aim of the study: Our aim is to describe the growth potential of borderline left ventricles after pulmonary arteries banding (PAB) and arterial duct stenting (ADS). Methods: 44 patients (mean weight 3 Kg, from 1,9 to 4,2 Kg), who were born with different hypoplastic LV variants underwent hybrid palliation at 3,6 days (1 to 7) in our institution between October 2011 and January 2018. We divided 36 patients into 3 groups according to the severity of LV hypoplasia: 14 pts with MA or MS and AoA, who are not supposed to show any growth of LH structures over time, 6 pts with IAoA and VSD whose LV is usually suitable for biventricular repair, and 16 pts with intermediate features. The latter group included pts with MS/AS, right unbalanced AVSD or Shone complex, all of them with severely underdeveloped LV, expressed by LV mass below -2 Z scores. Among this 16 pts we further distinguished three subgroups, according to the subsequent surgical treatment they underwent after the interstage period and potential LV growth: group 1 had single ventricle staged palliation (5 patients), group 2 biventricular repair (8 patients) and group 3 early death occurrence (3 patients). Two-dimensional echocardiograms of patients from group 1 and 2 were retrospectively reviewed, comparing examination recorded at birth with those obtained 4 months after hybrid palliation. Results: Aortic annulus, aortic root, mitral and tricuspid annulus, LV systolic and diastolic dimension, systo-diastolic volumes and mass, LV long-axis to heart long-axis ratio (LAR), transverse and distal arch and aortic isthmus diameters were used. LV mass and volumes are critically small in both groups at birth. Although a trend towards growth can be seen for almost all the analyzed parameters, a significant change of LV mass and volumes from pre- to post-hybrid procedure is evident in group 2, which is absent in group 1. Conversely, parameters like aortic annulus, aortic root and LAR in group 1, already at birth, were significantly smaller than they were in group 2. Conclusion: The goal in the treatment of borderline LV is to postpone the decision until the time LV has fully expressed its growth potential: then, many more biventricular repairs will be reached than at the time of first evaluation.

Anatomic and clinical characterization of the narrow distal aorta and implications after endovascular aneurysm repair

ObjectiveThe purpose of this analysis was to compare 1-year clinical outcomes after endovascular repair of abdominal aortic aneurysms with the EXCLUDER device in patients with standard and narrow aortic bifurcations (AOBs). MethodsData were prospectively collected from a 1055-participant subset of the multicenter Global Registry for Endovascular Aortic Treatment (GREAT) treated for abdominal aortic aneurysm repair between August 2010 and September 2015. There were 117 patients with a narrow AOB (NB; defined as <16 mm) and 938 patients with a standard bifurcation (SB). The 30-day and 1-year morbidity, mortality, and reintervention outcomes were analyzed, with Kaplan-Meier survival curve analysis conducted on freedom from mortality and freedom from reintervention. ResultsThe mean distal aortic neck diameter was 12.4 mm in the NB cohort and 25.3 mm in the SB cohort (P < .001), with NB patients also exhibiting significantly smaller diameter proximal aortic necks (P < .001). Patients in the NB cohort were more often female (25.6% vs 15.1%; P = .004) and with more severe comorbidity burden. There was a significantly higher rate of surgical cutdown access in the NB cohort (P < .001). Procedural survival was 100% in both groups. The 30-day mortality and safety outcomes were similar; however, all-cause mortality was significantly higher in the SB cohort through 1 year (P = .02). The 1-year freedom from mortality was estimated as 92.1% in the SB cohort and 99.1% in the NB cohort. Freedom from reintervention was estimated as 95.1% in the SB cohort and 92.8% in the NB cohort at 1 year. Through 1-year follow-up, 24 SB patients (2.6%) and 4 NB patients (3.4%) exhibited an endoleak requiring reintervention (P > .99). Type II endoleaks represented 72% and 60% of treated endoleaks, respectively. Through 1 year, 10 SB patients (1.0%) and 2 NB patients (1.7%) exhibited occlusive/thrombotic events (P = .54). There were no reported instances of kinking, migration, fracture, compression, or dissection through 1 year in either cohort. One SB patient experienced thoracic aortic aneurysm rupture. ConclusionsThe 1-year outcomes after endovascular aneurysm repair with the EXCLUDER device were comparable in the NB and SB cohorts. A narrow AOB was not found to be associated with a higher incidence of later limb occlusions or endoleaks. Female patients were disproportionately more likely to have a narrow AOB, which correlated with narrowed proximal necks and access vessels, and a more severe comorbidity burden.

Point-of-Care Ultrasound Performed by a Medical Student Compared to Physical Examination by Vascular Surgeons in the Detection of Abdominal Aortic Aneurysms

The use of point-of-care ultrasound (POCUS) has become increasingly prevalent in medical practice as a non-invasive tool for focused bedside diagnosis. Consequently, some medical schools have begun implementing POCUS training as a standard in their medical school curriculum. The feasability and value of introducing POCUS training at the medical student level to screen for abdominal aortic aneurysms (AAA) should be explored. Given this, the objective of our study was to determine the test characteristics of point-of-care ultrasonography performed by a medical student versus physical examination by vascular surgeons compared to a gold standard reference scan for the detection of AAAs. We conducted a prospective, observer-blinded study recruiting patients from an outpatient vascular surgery clinic. Participants were screened for AAAs by standardized physical examination by a blinded vascular surgeon, followed by a POCUS examination by a blinded medical student. The student underwent prior training by a vascular sonographer and emergency physician on 60 patients (16 were supervised). Ultrasonography was used to visualize and measure the proximal, mid, and distal aortic diameters. The maximal aortic diameter was noted and compared with measurements obtained by the reference scan (computed tomography scan or vascular sonographer-performed ultrasound). Reference scans were completed within 3months of the recruitment visit. A total of 57 patients were enrolled over a 5-month period between October 2015 and March 2016. Mean age of recruited patients was 71years, and 61% were male. Mean body mass index was 27.9±4.3, and mean waist-to-hip ratio was 0.96±0.10. Sixteen AAAs were detected by the reference scan, with an average maximal aortic diameter of 44.9mm. Physical examination by a vascular surgeon detected 11 of 16 AAAs with 2 false positives (sensitivity and specificity of 66.7% [95% confidence interval [CI], 38.4-88.2] and 94.4% [95% CI, 81.3-99.3], respectively). POCUS detected 15 of 16 AAAs (sensitivity and specificity of 93.3% [95% CI, 68.1-99.8] and 100% [95% CI, 88.4-100], respectively). Seven of the 64 POCUS scans were indeterminate (>1cm of the aorta was not visualized). Average time to conduct the physical examination was 35sec versus 4.0min for point-of-care ultrasonography. There was a strong linear correlation (R2=0.95) between maximal aortic diameter measured by point-of-care ultrasonography versus reference scan with a mean absolute difference of 2.6mm. Point-of-care ultrasonography performed by a medical student is highly accurate and more effective in detecting AAAs than physical examination by vascular surgeons. The introduction of POCUS training at the medical student level and its wide-scale implementation as an extension to physical examination may lead to improved detection of AAAs.

Abstract 334: Collateral Development in Swine after Ligation of Native Leg Arteries

Introduction: The development of collateral vasculature is a key mechanism compensating for arterial occlusions in patients with Peripheral Artery Disease (PAD). We aimed to examine the development of collateral pathways after ligation of native vessels in a porcine model of PAD. Methods: Right hindlimb ischemia was induced in domestic swine (N=11, male, 26-57 kg) using two different versions of arterial ligation. Version 1 (N=6) consisted of ligation/division of the right external iliac, profunda femoral (RPFA) and superficial femoral arteries (RSFA). Version 2 (N=5) consisted of the ligation of Version 1 with additional ligation/division of the right internal iliac artery (RIIA). Development of collateral pathways was evaluated with standard angiography at baseline (prior to arterial ligation) and at termination (4-8 weeks later). Relative luminal diameter of the arteries supplying the ischemic right hindlimb were determined by 2D angiography, as percent of the size of the distal aortic diameter. Results: The pathway connecting the RIIA to the RPFA and RSFA/popliteal artery of the ischemic limb was the dominant collateral pathway in version 1. Mean luminal diameter (± standard error) of the RIIA at termination increased by 39.4± 5.5% (P&lt;0.01) compared to baseline. There were two co-dominant collateral pathways in version 2. The first pathway connected the common internal iliac trunk and left internal iliac artery to the reconstituted RIIA which then supplied the RPFA and RSFA/popliteal arteries. The second pathway connected the left profunda artery to the reconstituted RPFA. Mean diameter (± standard error) of the common internal iliac trunk and left profunda artery increased at termination by 23.7± 7.6% and 24.8± 7.4%, respectively (p &lt; 0.05). Conclusion: Two versions of hindlimb ischemia induction (right ilio-femoral artery ligation with and without right internal iliac artery ligation in swine produced differing collateral pathways along with changes to the diameter of the inflow vessels. Radiographic and anatomical data of the collateral formation in this porcine model has value in investigation of the pathophysiology of hindlimb ischemia, and assessment of angiogenic therapies as potential treatments for PAD.

Double fixation for abdominal aortic aneurysm repair using AFX body and Endurant proximal aortic cuff: mid-term results.

Our goal was to evaluate the use of an AFX main body combined with an Endurant proximal aortic cuff to treat selected patients with an abdominal aortic aneurysm (AAA) associated with anatomical challenges, such as a small distal aortic diameter and a hostile aortic neck. A retrospective analysis of prospectively collected data from 2 vascular institutions identified 14 elective patients with an AAA (all men, 73.5 ± 5.1 years) treated with the AFX main body combined with an Endurant proximal aortic cuff. Patients had a small distal aortic diameter (median 19 mm) and a short or angulated proximal aortic neck (median length 20 mm, range 9-26 mm, median angulation 41.5°, range 23-80°). Six patients (42.9%) had an aortic neck that did not meet the indications for use of the AFX proximal aortic cuff. Primary technical success was achieved in all patients with no 30-day device-related complications or deaths. During a median follow-up period of 13 months (range 6-28 months), no re-intervention was needed. The diameter of the aneurysmal sac decreased from 57.6 ± 5.6 mm preoperatively to 50.4 ± 4.9 mm (P < 0.001) postoperatively. There were no aneurysm-related deaths or ruptures. No migration, disconnection or type I or III endoleak was observed. In 5 of the 6 patients, the initial type II endoleak spontaneously resolved during follow-up, whereas that in the remaining patient persisted without any change in the diameter of the aneurysmal sac. In patients with complex AAA anatomical configurations combining a hostile aortic neck and a narrow aortic bifurcation, the use of an AFX main body combined with an Endurant proximal aortic cuff seems to be feasible with favourable mid-term results.

Posttraumatic Resuscitation Affects Stent Graft Sizing in Patients with Blunt Thoracic Aortic Injury

Patients with blunt aortic injury often present to the emergency department in a relatively hypovolemic state. These patients undergo extensive inhospital resuscitation. The effect of posttraumatic resuscitation on aortic diameter has implications for stent graft sizing. The potential utility of repeat aortic imaging after resuscitation remains unclear. A retrospective chart review of all adult patients presenting to a Level I trauma center between the years 2007 and 2013 was performed. Fifty-three patients were identified with a diagnosis of traumatic aortic injury. Of those, 10 had 2 CT scans before aortic repair and were selected as the study population for analysis. After resuscitation, there was a significant increase in aortic diameter both proximal and distal to the aortic injury: proximal aortic diameter increase of 1.97 mm and distal aortic diameter increase of 1.48 mm. This retrospective study shows that after resuscitation, there is a significant increase in proximal and distal aortic diameter. Interval reimaging of the thoracic aorta may be beneficial after adequate stabilization of the patient's other injuries. In certain cases, more appropriate sizing may prevent a device-related complication.

Endovascular aortic aneurysm repair in patients with narrow aortas using bifurcated stent grafts is safe and effective

Narrowing of the distal aortic bifurcation can result in stent graft compression or arterial disruption during endovascular aortic aneurysm repair (EVAR). The aim of our study was to evaluate results of EVAR in patients with narrow distal aortic bifurcations. We reviewed the clinical data of 1070 patients who underwent EVAR between 2000 and 2011. Digital computed tomography angiograms were analyzed using centerline of flow measurements to determine aortic diameters. Patients with a distal aortic bifurcation diameter <18 mm were included in the study. End points were technical success, aortic disruption with retroperitoneal hemorrhage, stent graft complications (endoleaks, migration, sac enlargement, stenosis), reintervention, and iliac limb patency. EVAR was used to treat 112 patients (84 men and 28 women; mean age, 75 years) with aortic bifurcation <18 mm, including 34 (30%) who had diameter of <14 mm. Mean outer and inner aortic bifurcation diameter was 16 ± 3 and 14 ± 2 mm, respectively. Bifurcated stent grafts were used in 106 patients (95%). Six patients (5%) had planned aortouniiliac converters with femoral crossover graft. The aortic bifurcation was dilated after placement of bifurcated stent grafts using kissing balloon angioplasty in 80 patients (75%). All bifurcated stent grafts were successfully implanted, with no conversions to open repair or aortouniiliac converters. There were two early deaths (1.8%), and 12 patients (11%) developed early complications. No aortic disruptions or retroperitoneal hematomas occurred in the group treated with bifurcated grafts. After a median follow-up of 35 months, 11 patients (11%) treated by bifurcated stent grafts required reintervention to treat endoleak (n = 6) or iliac limb stenosis/occlusion (n = 5). One patient (17%) treated by aortouniiliac converter developed critical stenosis of an aortouniiliac graft limb, which was successfully treated with balloon angioplasty 29 months after the initial surgery. At 1 and 5 years, freedom from reintervention was 91% ± 3% and 84% ± 4%, respectively, for bifurcated stent grafts and 100% and 83% ± 10%, respectively, for aortouniiliac converters. Primary and secondary iliac limb patency was 98% ± 3% and 100%, respectively, for bifurcated stent grafts and 83% ± 10% and 100%, respectively, for aortouniiliac converters. EVAR with bifurcated stent grafts is safe and effective in patients with a narrow distal aortic diameter, even when the aortic bifurcation measures <14 mm. Adjunctive balloon dilatation did not result in any bleeding complications from aortic disruption, and limb patency was excellent. Aortouniiliac converters are rarely needed for this indication.

Reoperation for enlargement of the distal aorta after initial surgery for acute type A aortic dissection

We investigated the long-term outcomes of repair for acute type A aortic dissection on the basis of false lumen status and assessed treatment modalities for the enlarged downstream aorta. Between January 1990 and March 2013, 534 patients underwent surgery for acute type A aortic dissection. In-hospital mortality was 9.3% (50/534), and follow-up was 98% (472/484). Of the 472 hospital survivors, 451 (96%) underwent contrast-enhanced computed tomography within 1 month of surgery. Risk-adjusted survival and distal aortic events were investigated in these 451 patients. Surgical outcomes of distal reoperations were assessed in 37 patients. Postoperative false lumen patency was 62% (280/451). Eighteen patients died of aortic rupture, 17 (94%) with a patent false lumen. A patent false lumen decreased survival (hazard ratio [HR], 1.70; P=.012) and increased distal aortic events (HR, 4.11; P=.001). Other predictors identified were age (HR, 1.07; P<.001) and male sex (HR, 1.89; P=.002) for late mortality, and Marfan syndrome (HR, 6.6; P<.001), distal aortic diameter greater than 45 mm (HR, 4.4; P<.001), and nonresection of the primary entry (HR, 2.3; P=.005) for distal aortic events. Distal reoperations comprised open repair of the arch (n=13), descending aorta (n=16), or thoracoabdominal aorta (n=7) or thoracic endovascular aortic repair (n=7), with no in-hospital death or paraplegia. Although thoracic endovascular aortic repair yielded false lumen thrombosis around the stent graft in 80% of patients (4/5), complete false lumen thrombosis was achieved in 20% (1/5). False lumen patency influences the late outcomes of acute type A aortic dissection repair. Outcomes of distal reoperation were acceptable; thus, careful follow-up and timely reoperation may improve the late outcomes.

966Using Carotid-subclavian artery Index and Isthmus-descending Aorta ratio with cardiac MR for detection of coarctation

Objective: Coarctation of the aorta is one of the most common congenital heart diseases. Its diagnosis may be difficult in the presence of complex cardiac defects, congenital disease or of a poor echocardiographic window. In the preset study we demonstrate the carotid-subclavian artery index (CSA index) and the isthmus—descending aorta ratio (I/D ratio), two recently described indexes, are effective in detection of isolated and complex aortic coarctation in patients using cardiac MR. Many study using these index by echocardiography but there is a few study concerning using MR for detection of coarctation. Method: This is a retrospective cohort study in a tertiary care cardiac hospital. Review of all MR (0-40 aged) with a diagnosis of coarctation seen at our institution between 2010 and 2011. An age- and sex-matched control group without coarctation was constituted. Offline MR measurements of the aortic arch were performed in order to calculate the CSA index and I/D ratio. The CSA index is the ratio of the distal aortic arch diameter to the distance between the left carotid artery and the left subclavian artery. It is highly suggestive of a coarctation when it is <1.5. The I/D ratio defined as the diameter of the isthmus to the diameter of the descending aorta, suggests an aortic coarctation when it is less than 0.64. Results: Sixty-five patients included in coarctation group, 84 in control group. Patients I n coarctation groups had a significantly lower CSA index than patients in the control group (1.27 + 0.06 vs. 2.82 + 0.9, p < 0.05). I/ D ratio (0.4 + 0.14) were significantly lower than the cut- off in comparison to the previous study (0.64). Associated cardiac defects, age and sex did not alter on the CSI index or I/ D ratio. Cut-off pint of 1.5 was considered 96% as sensitivity and 76% specificity in detection of coarctation of aorta. The positive and negative predictive value was 84.4% and 94.1% respectively. Conclusion: The association of both indexes improves sensitivity and permits diagnosis of coarctation in all patients based solely on a cardiac MR measurement. We have demonstrated that CSI and I/ D ratio index, are independently of clinical status, associated anomalies age and sex, and are useful tools for detecting of aortic coarctation with cardiac MR. Keywords: Aortic Coarctation; CSI index, I/ D index, cardiac MR, congenital heart defect