Aortic Length Research Articles

Influence of Anatomic Angulations in Chimney and Fenestrated Endovascular Aneurysm Repair

The lack of widespread availability of Fenestrated endovascular aneurysm repair (F-EVAR) encouraged alternative strategies. Hence, Chimney graft (CG)-EVAR spread when costs, manufacturing delays, or anatomy preclude F-EVAR. Our objective is to evaluate CG- and F-EVAR outcomes depending on the angulation of target renal arteries and hostility of iliac accesses in order to determine the potential impact of a choice made between both techniques on the basis of preoperative anatomic criteria. Consecutive patients treated by CG-EVAR or F-EVAR, from January 2010 to January 2015, were considered for inclusion. Anatomic parameters were defined by preoperative computed tomography angiography. A subgroup analysis was performed depending on renal arteries' angulation (cut-off: -30°) and iliac arteries' hostility (cut-off: diameter<6mm, tortuosityindex=3). Twenty-six patients were included the CG group (mean age 74.7±6.9years, 30 target vessels) and 66 in the F-EVAR group (71.7±7.9years, 133 target vessels). Infrarenal aortic neck length was significantly longer for CG-EVAR (3.3±3.7 vs. 1.8±3.2mm, P=0.04), while the distance between the superior mesenteric artery and highest renal artery was shorter in the CG group (11.7±6.2mm vs. 14.1±5.9mm, P=0.06). Longitudinal angulation of the right renal artery was not statistically different between both groups, while the left renal artery presented with a significantly more downward angulation in the CG group (-32.0±15.3 vs. -19.0±19.6, P=0.003). There were significantly more grade 3 iliac tortuosity indexes for CG-EVAR (P=0.03) with significantly smaller external iliac diameters (7.8±1.7 vs. 8.8±1.6mm, P=0.0009). There was 1 renal artery early occlusion in the <-30° CG subgroup and 2 in the <-30° F-EVAR subgroup where severe downward angulation crushed the stents, with a tendency toward higher early occlusions compared with the ≥-30° F-EVAR subgroup (P=0.054). Mean follow-up duration was 20months in the CG group and 14 in the F-EVAR group. Kaplan-Meier estimates showed no significant difference in terms of overall survival, freedom from reintervention, freedom from type I or III endoleak, or patency. In the CG group, 14 patients (53.8%) presented with hostile iliac accesses without any significant difference in terms of limb events. CG-EVAR is a complementary strategy to F-EVAR, and understanding which technique is applicable to which patient is important to improve outcomes. Our results suggest that considering renal artery angulation and diameter, iliac artery hostility, and aortic neck length among other parameters may help the surgeon make a decision toward the endovascular strategy that seems best suited for each specific patient.

Does the Traversing Length of the Aorta Change After Closing Wedge Osteotomy for Ankylosing Spondylitis Patients With Thoracolumbar Kyphosis?: A Magnetic Resonance Imaging Investigation.

A prospective magnetic resonance imaging (MRI) study. To investigate the change in aortic traversing length in patients with thoracolumbar kyphosis secondary to ankylosing spondylitis (AS) after closing wedge osteotomy (CWO). The CWO has been widely adopted for the correction of thoracolumbar kyphosis caused by AS. During this procedure, the aorta may be elongated in the instrumented area, which implies a potential risk of the aortic injury. To date, no reports have been specifically published using MRI to investigate the alteration in aortic traversing length in patients with AS undergoing CWO. From June 2013 to July 2015, 24 patients with AS with thoracolumbar kyphosis with a mean age of 38.1 years were recruited in the present study. All patients underwent single-level CWO. MRI examinations were performed before and 2 weeks after surgery. For each subject, the aortic diameter and length were measured on the MRI. Radiographic measurements included the global kyphosis, thoracic kyphosis, lumbar lordosis, local kyhosis, angle of fusion levels, and anterior height of the osteotomized vertebra. The height of these patients was also recorded. The aortic traversing length significantly increased by an average of 2.0 cm after surgery. Significant changes in height, global kyphosis, lumbar lordosis, local kyphosis, and angle of fusion levels were observed (P < 0.01), whereas the anterior height of the osteotomized vertebra was comparable before and after surgery (P > 0.05). In addition, the correlation analysis revealed a significant correlation between the aortic traversing length and changes in global kyphosis, lumbar lordosis, local kyphosis, angle of fusion levels, and height (P < 0.01). The stretch of the aorta after CWO for the correction of thoracolumbar kyphosis was quantitatively verified by MRI investigation in the present study. Spine surgeons should be aware of the potential vulnerability of aortic injury in patients with AS undergoing CWO. 4.

Midterm Results of Proximal Aneurysm Sealing With the Ovation Stent-Graft According to On- vs Off-Label Use

Purpose: To compare the use of the Ovation stent-graft according to the ≥7-mm neck length specified by the original instructions for use (IFU) vs those treated off-label (OL) for necks <7 mm long. Methods: A multicenter retrospective registry (TriVascular Ovation Italian Study) database of all patients who underwent endovascular aneurysm repair with the Ovation endograft at 13 centers in Italy was interrogated to identify patients with a minimum computed tomography (CT) follow-up of 24 months, retrieving records on 89 patients (mean age 76.4±2.4 years; 84 men) with a mean follow-up of 32 months (range 24–50). Standard CT scans (preoperative, 1-month postoperative, and latest follow-up) were reviewed by an independent core laboratory for morphological changes. For analysis, patients were stratified into 2 groups based on proximal neck length ≥7 mm (IFU group, n=57) or <7 mm (OL group, n=32). Outcome measures included freedom from type Ia endoleak, any device-related reintervention, migration, and neck enlargement (>2 mm). Results: At 3 years, there was no aneurysm-related death, rupture, stent-graft migration, or neck enlargement. There were no differences in terms of freedom from type Ia endoleak (98.2% IFU vs 96.8% OL, p=0.6; hazard ratio [HR] 0.55, 95% CI 0.02 to 9.71 or freedom from any device-related reintervention (92.8% IFU vs 96.4% OL, p=0.4; HR 2.42, 95% CI 0.34 to 12.99). In the sealing zone, the mean change in diameters was −0.05±0.8 mm in the IFU group and −0.1±0.5 mm in the OL group. Conclusion: Use of the Ovation stent-graft in patients with neck length <7 mm achieved midterm outcomes similar to patients with ≥7-mm-long necks. These midterm data show that the use of the Ovation system for the treatment of infrarenal abdominal aortic aneurysm is not restricted by the conventional measurement of aortic neck length, affirming the recent Food and Drug Administration–approved changes to the IFU.

Aortic length measurements for pulse wave velocity calculation: manual 2D vs automated 3D centreline extraction

BackgroundPulse wave velocity (PWV) is a biomarker for the intrinsic stiffness of the aortic wall, and has been shown to be predictive for cardiovascular events. It can be assessed using cardiovascular magnetic resonance (CMR) from the delay between phase-contrast flow waveforms at two or more locations in the aorta, and the distance on CMR images between those locations. This study aimed to investigate the impact of different distance measurement methods on PWV. We present and evaluate an algorithm for automated centreline tracking in 3D images, and compare PWV calculations using distances derived from 3D images to those obtained from a conventional 2D oblique-sagittal image of the aorta.MethodsWe included 35 patients from a twin cohort, and 20 post-coarctation repair patients. Phase-contrast flow was acquired in the ascending, descending and diaphragmatic aorta. A 3D centreline tracking algorithm is presented and evaluated on a subset of 30 subjects, on three CMR sequences: balanced steady-state free precession (SSFP), black-blood double inversion recovery turbo spin echo, and contrast-enhanced CMR angiography. Aortic lengths are subsequently compared between measurements from a 2D oblique-sagittal plane, and a 3D geometry.ResultsThe error in length of automated 3D centreline tracking compared with manual annotations ranged from 2.4 [1.8-4.3] mm (mean [IQR], black-blood) to 6.4 [4.7-8.9] mm (SSFP). The impact on PWV was below 0.5m/s (<5%). Differences between 2D and 3D centreline length were significant for the majority of our experiments (p < 0.05). Individual differences in PWV were larger than 0.5m/s in 15% of all cases (thoracic aorta) and 37% when studying the aortic arch only. Finally, the difference between end-diastolic and end-systolic 2D centreline lengths was statistically significant (p < 0.01), but resulted in small differences in PWV (0.08 [0.04 - 0.10]m/s).ConclusionsAutomatic aortic centreline tracking in three commonly used CMR sequences is possible with good accuracy. The 3D length obtained from such sequences can differ considerably from lengths obtained from a 2D oblique-sagittal plane, depending on aortic curvature, adequate planning of the oblique-sagittal plane, and patient motion between acquisitions. For accurate PWV measurements we recommend using 3D centrelines.

Quantification of motion of the thoracic aorta after ascending aortic repair of type-A dissection.

To quantify cardiac and respiratory deformations of the thoracic aorta after ascending aortic graft repair. Eight patients were scanned with cardiac-resolved computed tomography angiography during inspiratory/expiratory breath-holds. Aortic centerlines and lumen were extracted to compute the arclength, curvature, angulation, and cross-section shape. From systole to diastole, the angle of graft[Formula: see text]arch increased by 2.4[Formula: see text] ± 1.8[Formula: see text] (P < 0.01) and the angle of arch[Formula: see text]descending aorta decreased by 2.4[Formula: see text] ± 2.6[Formula: see text] (P < 0.05), while the effective diameter of the proximal arch decreased by 2.4 ± 1.9% (P < 0.01), a greater change than those of the graft or distal arch (P < 0.05). From inspiration to expiration, the angle of graft[Formula: see text]arch increased by 2.8[Formula: see text] ± 2.6[Formula: see text] (P < 0.02) with the peak curvature increase (P < 0.05). Shorter graft length was correlated with greater cardiac-induced graft[Formula: see text]arch angulation, and longer graft length was correlated with greater respiratory-induced arch [Formula: see text] descending aorta angulation (R [Formula: see text] 0.50). The thoracic aorta changed curvature and angulation with cardiac and respiratory influences, driven by aortic root and arch motion. The thoracic aortic geometry and deformation are correlated with the ascending aortic graft length.

Age-related changes of thoracic aorta geometry used to predict the risk for acute type B dissection

AimsRisk models that use a single aortic diameter threshold have failed to successfully predict acute type B aortic dissection (TBAD). We sought to identify meaningful age-indexed anatomical variables to predict TBAD risk. Methods and resultsA geometric deformable model, consisting of virtual elastic balloons that inflate inside a vessel lumen, was developed to quantify thoracic aorta geometry. In the presence of TBAD, true and total artery lumen morphology were assessed. A stepwise logistic model was built to predict TBAD risk. Initial covariates included age, gender, body mass index and all anatomic variables not directly related to the dissected segment. Patients with acute TBAD (n=34, 62±12years old, 57% male gender) were compared with subjects with symptoms of dissection, but with a subsequent negative diagnosis (n=51, 62±12years old, 76% male gender). Patient risk factors did not differ between groups. Most aortic anatomical variables were age-dependent. Aortic size was larger in every segment of the dissected with respect to non-dissected aortas (p<0.001). Variables entering the TBAD risk prediction model were aortic arch diameter, thoracic aorta length and age (predictability=0.9764, r=0.85), confirmed by a bootstrap internal validation. In dissected aortas, the true lumen volume was correlated to age (r=0.72). ConclusionsTBAD probability increases with a larger aortic arch diameter and a longer thoracic aorta, whereas threshold values increase with age. The aortic morphology was age-dependent. After dissection, true lumen volume correlated to age. The use of threshold values indexed to age should be encouraged to better prevent and eventually treat TBAD.

Retroperitoneal paraganglioma presenting as hypertension and paraparesis in young

Paragangliomas(PGL) are rare tumours that arise from extra-adrenal paraganglia. Extra-adrenal paragangliomas account for only 5 to 10% of all paragangliomas and may present incidentally as a mass. Typical triad of fluctuating hypertension, headache, and sweating is not always present which makes the diagnosis sometimes difficult. Extraadrenal retroperitoneal PGLs are functionally active more often than previously reported and that they are readily detected by soft tissue masses closely associated with the entire length of abdominal aorta. However, no CT feature was found that was unique for PGL.1 Herein we describe the clinical, radiological and pathological features in young patient presented for hypertension and paraparesis, and later on diagnosed as malignant abdominal paraganglioma with vertebral and lymph node metastasis.

Thoracic Endovascular Aortic Repair Migration and Aortic Elongation Differentiated Using Dual Reference Point Analysis

We evaluated patients using two reference points as a means for differentiating stent graft migration from aortic elongation. Conventional standards define migration as an absolute change in the distance from the distal graft ring to a distal landmark ≥10 mm compared with baseline measurement. Aortic elongation occurs over time in both healthy individuals and patients with aortic disease. Aortic elongation in patients with stent grafts may result in increased distal thoracic aortic lengths over time. These patients meet the standard definition for migration even if the stent has not moved in relation to the elongating aorta. This retrospective study evaluated the aortic length of 23 patients who were treated with the conformable Gore TAG thoracic endoprosthesis (W. L. Gore & Associates, Flagstaff, Ariz) in three clinical trials (dissection, traumatic injury, and aneurysm). Patients were selected having met the standard definition for migration. A standardized protocol was used to measure aortic centerline lengths, including the innominate artery (IA) to the most distal device ring, the IA to the celiac artery (CA), and the distal ring to the CA (Fig). Baseline lengths obtained from the first postoperative image were compared with length measurements obtained from the first interval at which they met standard definition for migration. The conventional standards for migration using a single reference point were compared with the use of dual reference points. Twenty of the 23 patients with endograft changes were deemed to have aortic elongation rather than true migration. The remaining three patients were deemed to have migration based on the IA to distal ring position compared with the IA to CA length change. The IA to CA interval length change was markedly greater in those with elongation than migration (Table). The distal ring to CA interval length change can be found in the Table. The IA to distal ring length was similar for elongation and migration (Table). These results highlight the dynamic changes that can occur in the aorta as a natural consequence of age. Employing two landmarks can account for these changes and proves to be an important factor, among others, in the differentiation of aortic elongation from true stent graft migration.TableInterval changes in aortic distancesMigration (n = 4)Elongation (n = 16)IA – CA change, mm−3.5 ± 5.423.8 ± 8.4IA – Distal ring change, mm2.5 ± 3.24.7 ± 5.5Distal ring – CA change, mm−9.8 ± 5.418.5 ± 6.6IA-CA and distal ring-CA lengths increased substantially in patients with elongation compared to those with migration. There was no apparent difference in length change between the IA – distal ring measurements. Open table in a new tab

Endovascular Aneurysm Sealing

Purpose: To report the early and 12-month results of a global registry of patients treated with endovascular aneurysm sealing (EVAS) for abdominal aortic aneurysms (AAAs). Methods: The EVAS FORWARD Global Registry was a postmarket, multicenter, open-label, single-arm registry that enrolled 277 patients (mean age 75 years; 228 men) treated with the Nellix EVAS system for nonruptured AAAs at 18 sites over a 1-year period. The cohort had challenging aortic anatomy, with 17% having a proximal aortic neck length <10 mm, 8% a neck angulation >60°, and 20% an iliac diameter >25 mm. Baseline and follow-up computed tomography images were assessed by an independent core laboratory, and major adverse events were reviewed by an independent safety committee. Results: Three patients died within 30 days of the procedure (none device-related). There were 13 endoleaks recorded in this time frame: 8 type Ia, 1 type Ib, and 5 type II. Root cause analysis demonstrated that the majority of type Ia endoleaks were due to technical error (low device placement and underfilling of the endobags). Between 30 days and 1 year, there were 4 new type Ia endoleaks; all were treated. There was also 1 type III endoleak between a Nellix device and a distal extension limb. At 1 year, the persistent endoleak rate was 0.7% (1 type Ia and 1 type II). The Kaplan-Meier estimates of freedom from types I and II endoleak at 12-month follow-up were 96% and 98%, respectively. The estimate of freedom from open conversion (n=7) was 98% at 12 months and the rate of freedom from any reintervention was 92%. The need for secondary intervention was associated with aortic morphology; for patients meeting the requirements of the instructions for use (IFU), the freedom from reintervention at 12 months was 98% compared with 86% when the implant was outside the IFU (p=0.009). At 1 year, the estimates of freedom from aortic-related and all-cause mortality were 98% and 95%, respectively. Conclusion: The EVAS FORWARD Global Registry documents the 12-month outcome of EVAS in an unselected group of patients with challenging aortic morphology. The results at present appear acceptable with regard to perioperative outcomes and complications. The type II endoleak rate is low. The place of EVAS in the armamentarium of techniques to treat AAAs will be defined by durability data in the longer term.

Results of standard suprarenal fixation endografts for abdominal aortic aneurysms with neck length ≤10 mm in high-risk patients unfit for open repair and fenestrated endograft

The aim of this study was to evaluate long-term outcomes of endovascular aneurysm repair (EVAR) using a standard suprarenal fixation endograft in abdominal aortic aneurysms (AAAs) with infrarenal neck length ≤10mm (short-neck AAA [SN-AAA]). From 2005 to 2010, data of high-risk patients with SN-AAA, unfit for open repair (OR) and fenestrated EVAR, were prospectively collected. Follow-up was performed by duplex ultrasound and contrast-enhanced ultrasound or computed tomography angiography at 1month, 6months, and 12months and yearly thereafter. The primary end point was AAA-related mortality. Secondary end points were proximal type I endoleak, freedom from reintervention, and AAA shrinkage (>5mm). Sixty patients (mean age, 74.9± 6.2years; American Society of Anesthesiologists class 3 [85%] and class 4 [15%]) were enrolled. The mean aneurysm diameter and neck length and diameter were 60.4± 12.2mm, 8.4± 1.6mm, and 23.5± 3mm, respectively. Four (7%) patients were symptomatic and 15 (25%) had rapid AAA enlargement (>5mm/6months). Cook Zenith Flex (Cook Medical, Bloomington, Ind) endografts (32) and Medtronic Endurant (Medtronic, Santa Rosa, Calif) endografts (28) were implanted. The mean follow-up was 51± 18months. Survival at 5years was 70%. There were three (5%) type I endoleaks. One was sealed by endovascular reintervention, and two (3%) underwent conversion to OR for AAA rupture at 8 and 36months. Both patients died (2/60; 3% AAA-related mortality). Reinterventions were necessary for another five (8%) patients, and they were not proximal neck related. Freedom from reintervention at 5years was 90%. In 49 (82%) cases, there was AAA shrinkage; the AAA diameter remained stable in nine (15%) and increased in two (3%) cases. Severe proximal angle (α neck angle ≥60 degrees) was associated with type Iendoleak (P= .010) and reinterventions (P= .010). The neck length<7mm(P= .030) was associated with reinterventions (P= .017). Suprarenal fixation EVAR in SN-AAA with a straight, not wide neck and 7- to 10-mm aortic neck length can be considered safe and effective in patients who are unfit for OR and fenestrated EVAR. For these cases, long-term data showed acceptable results in preventing aneurysm rupture and related mortality.

Migration of the Nellix endoprosthesis

This study reports the incidence and sequelae of migration of the Nellix (Endologix Inc, Irvine, Calif) endoprosthesis after endovascular aneurysm sealing. A review was performed of the follow-up imaging of all endovascular aneurysm sealing patients in a university hospital endovascular program who had a minimum follow-up of 1year. The first postoperative and latest follow-up computed tomography scans were used to measure the distances between the proximal and distal borders of the stent grafts relative to reference vessels using a previously validated technique. Device migration was based on previously established criteria and defined as any stent graft movement of ≥4mm related to a predefined reference vessel. Device movement in a caudal direction was given a positive value, and movement in a cranial direction was denoted by a negative value. Eighteen patients (35 stent grafts) were eligible for inclusion in this retrospective review. The mean preoperative abdominal aortic aneurysm diameter was 57mm (standard deviation [SD], 5; range, 50-67mm) and aortic neck length was 30mm (SD, 16; range, 6-62mm). Proximal migration, according to study definitions, was identified in six stentgrafts (17%), all in a caudal direction. At 1year the mean proximal migration distance was+6.6mm (SD, 1.6; range,+4.7-+9.2mm). Migration occurred in a single stent graft in four patients and bilaterally in one. No distal migration occurred. Proximal migration of the Nellix endoprosthesis does occur and was without any sequelae in our series. Further investigations into the long-term positional stability of the Nellix device, together with a more thorough understanding of the etiology and consequences of migration, are required.

Ascending aortic elongation and the risk of dissection.

Unlike aneurysm formation, the role of ascending aortic elongation in the pathogenesis of Type A aortic dissection (TAD) is largely unclear. We investigated the morphology of healthy, dissected and predissection aortas with a focus on ascending aortic length. We retrospectively compared clinical and computer tomography angiography (CTA) data from TAD patients (n = 130), patients who developed a TAD in the further clinical course (preTAD, n = 16) and healthy control patients who received a CTA for non-aortic emergencies (n = 165). The length of the ascending aorta was defined as the distance between the sinotubular junction (STJ) and the brachiocephalic trunk (BCT) at the central line, the outer and inner curvature as well as the direct distance in the frontal and sagittal planes. Additionally, the aortic diameters were analysed. In the healthy controls, we found a positive correlation of age with the aortic diameter (r = 0.57) and aortic length (r = 0.42). The correlation of the respective parameters with the body size was negligible (r < 0.2). The median ascending aortic diameter at the height of the pulmonary artery in TAD (50 mm) was significantly (P < 0.001) larger compared with the respective diameter of the healthy aortas (34 mm). The diameter of the preTAD aortas (40 mm) was also significantly larger compared with the healthy controls. These proportions were similar in all the aortic diameters. The midline length of the healthy ascending aortas was 71 mm. In the preTAD and TAD aortas, the same values were 81 mm and 92 mm, respectively (both P < 0.001). We evaluated the linear distance between the STJ and the BCT in the frontal plane as an easy-to-measure parameter of aortic length. In the TAD aortas (108 mm) and preTAD aortas (97 mm), this distance was significantly longer compared with the healthy aortas (84 mm). Aortic diameter might not be an optimal parameter to predict dissection. Most aortas dissect at diameters below 55 mm. Both the TAD and preTAD aortas were elongated compared with the healthy controls. Thus, aortic elongation may play a role in the pathogenesis of and may be a risk factor for TAD.

Volume analysis of true and false lumens in acute complicated type B aortic dissections after thoracic endovascular aortic repair with stent grafts alone or with a composite device design

This study compared the 12-month evolution of the aortic volume in patients who underwent thoracic endovascular aortic repair (TEVAR) with stent grafts alone or a composite device (Zenith TX2 stent graft and Zenith Dissection stent; Cook Medical, Bloomington, Ind) for acute (≤2weeks from onset) complicated type B aortic dissection. This was a retrospective analysis comparing prospectively collected data from 45 patients who underwent standard TEVAR repair at three European institutions (TEVAR group) and 39 patients in the Study of Thoracic Aortic type B Dissection using Endoluminal Repair (STABLE I) study who received a composite device (STABLE group). The analysis included consecutive patients treated for acute, complicated type B dissection and with available baseline and 12-month computed tomography imaging. Volume analysis was performed by using a semiautomated centerline algorithm. Baseline demographics, medical history, extent of dissection, and clinical indications were largely similar between the two groups. There was no difference in the length of aorta covered by stent grafts (167± 47mm in STABLE and 184± 49mm in TEVAR; P= .11). The STABLE group had an initial larger false lumen volume in the thoracic (203± 72cm(3) vs 162± 74cm(3); P= .01) and abdominal aorta (63± 29cm(3) vs 36± 27cm(3); P< .001). In the thoracic aorta, each group exhibited a significant increase in true lumen volume and a significant decrease in false lumen volume through 12months. The total aortic volume increased significantly in the STABLE group (P< .001) but not in the TEVAR group. In the abdominal aorta, only the STABLE group exhibited a significant increase in the true lumen volume (P< .001) and a significant decrease in the false lumen volume (P= .004) postoperatively. At 12months, the true lumen continued to increase significantly in the STABLE group (P= .03). However, no statistically significant difference was detected when the two groups were compared for the overall changes in the true lumen and false lumen volumes from preprocedure to 12months, and both groups exhibited a statistically significant increase in total abdominal aortic volume at 12months. There was no statistical difference between the two groups in the proportions of patients who experienced >10% changes in the thoracic or abdominal total lumen volume after TEVAR. Patients in the two groups (all survived 12months) had similar clinical outcomes, including rupture, conversion, and reinterventions. According to this volume analysis, thoracic endografting for acute complicated type B dissections promotes significant thoracic aortic remodeling. The use of bare-metal dissection stents leads to significant true lumen expansion and false lumen regression in the early follow-up and to subsequent continued true lumen expansion in the abdominal aorta; however, a definitive benefit in aortic remodeling over TEVAR alone was not demonstrated at 1year.

Supraceliac Aortic Clamping for Repair of Ruptured Abdominal Aortic Aneurysm in Patients with Short Aortic Neck Length

Objective: Prompt bleeding control with proximal aortic clamping and subsequent aortic repair are very important for ruptured abdominal aortic aneurysm. However, unsuitable anatomy, such as short aortic neck length, not only disturbs the means to an expeditious repair, but may also increase morbidity and mortality. In the present study, we aimed to evaluate the efficacy of supraceliac aortic clamping for improving surgical outcomes for patients with ruptured abdominal aortic aneurysm, who have a short aortic neck length. Method: Between April 2010 and September 2015, eighteen patients underwent emergent open surgical repair of ruptured abdominal aortic aneurysm. Eight patients with a short aortic neck length underwent supraceliac aortic clamping, and 10 underwent infrarenal aortic clamping. Results: The mean supraceliac aortic clamping time was 30 ± 7 minutes. There was 1 operative death in the infrarenal aortic clamping group due to respiratory failure, and the overall operative mortality was 6%. There were no significant differences between the 2 groups with respect to postoperative complication rates or mortality. Furthermore, there were no significant differences in variables of renal function between the 2 groups, through-out the study period. Conclusion: Supraceliac aortic clamping was associated with minimal mortality and morbidity, but not with harmful effects on postoperative renal function. Thus, supraceliac aortic clamping can be safely applied for ruptured abdominal aortic aneurysm with short aortic neck length.

Atheroprotective effects of pure tocotrienol supplementation in the treatment of rabbits with experimentally induced early and established atherosclerosis

BackgroundAtherosclerosis is the main cause of coronary artery disease -related deaths worldwide. The atheroprotective properties of pure tocotrienols (T3) in the absence of alpha-tocopherol (α-TCP) in vitamin E has not been extensively examined.AimTo determine the atheroprotective properties of T3 in early and established atherosclerosis rabbits.MethodsThirty New Zealand white rabbits were divided into two groups, B1 and B2 which represent early [fed 1% high cholesterol diet (HCD) for 2 weeks] and established (fed 1% HCD for 8 weeks) atherosclerosis. Each group was subdivided into three intervention arms: 1) T3–4 mg/kg, 2) T3–15 mg/kg and 3) vehicle without T3 (T3 negative) for 8 weeks. Serial fasting blood samples were obtained for lipid profile, and whole lengths of aorta were used to determine tissue markers of endothelial activation, inflammation and plaque stability.ResultsIn B1, atherosclerotic lesion in T3–4 mg/kg group was significantly reduced (p=0.008), while aortic tissue expression of vascular cellular adhesion molecule 1 (VCAM-1), interleukin-6 (IL-6) and matrix metalloproteinase (MMP-12) was reduced in T3–4 mg/kg compared to T3-negative rabbits group (0.2±0.1 vs. 28.5±3.1%; 3.0±1.6 vs. 14.0±1.7%; and 5.2±2.2 vs. 27.7±0.8%, respectively, p<0.05). T3–15 mg/kg group showed reduction in VCAM-1, E-selectin, IL-6 and MMP-12 (3.9±1.9 vs. 28.5±3.1%; 10.3±0.5 vs. 59.8±8.5%; 2.6±1.7 vs. 14.0±1.7%; and 16.2±3.2 vs. 27.7 0.8%, respectively, p<0.05). In B2, T3–4 mg/kg group reduced aortic tissue expression of intercellular adhesion molecule 1 (ICAM-1), E-selectin, IL-6, MMP-12 and MMP-9 compared to T3-negative rabbits group (29.9±2.4 vs. 55.3±1.3%; 26.7±1.5 vs. 60.5±7.6%; 15.7±0.7 vs. 27.7±4.8%; 34.8±2.7 vs. 46.5±3.4%; and 25.89±3.9 vs. 45.9±1.7%, respectively, p<0.05). T3–15 mg/kg group showed reduced VCAM-1, ICAM-1, E-selectin, IL-6, MMP-12 and MMP-9 (20.5±3.3 vs. 35.6±2.5%; 24.9±1.3 vs. 55.3±1.3%; 29.9±6.7 vs. 60.5±7.6; 11.3±2.2 vs. 27.7±4.8%; 23.0±1.7 vs. 46.5±3.4%; and 17.6±1.9 vs. 45.9±1.7%, respectively, p<0.05.ConclusionThese findings suggest the possible atheroprotective role T3 plays as an adjunct supplementation to standard treatment in the prevention of CAD.

Endovascular approach to complex aortic arch pathologies: state of the art.

Aortic geometry changes during life [1]. After relatively dynamic aortic length and diameter growth in the first two decades of life, it continuous to grow, attaining diameters 20 to 30% larger in the 7th than in the 2nd decade. Arterial hypertension, atherosclerosis, and still poorly-defined genetic risk factors add to natural aortic anatomy changes leading to rapid aortic segmental growth and ultimately aneurysms. Aortic arch aneurysms together with arch dissections and penetrating atherosclerotic ulcers are the most common arch pathologies requiring further therapy. New technologies give us an excellent opportunity to broaden the surgical armamentarium. Thoracic endovascular aortic repair (TEVAR) has dramatically changed aortic surgery within the last 15 years. It is not only a far less invasive approach than open surgery, but it also provides excellent results for complex pathologies in certain patients and may be applied even in those ineligible for open surgery [2, 3]. Thoracic endovascular aortic repair became the treatment of choice for traumatic aortic injury and acute complicated type B dissection. Aortic arch pathologies due to the arch's key role in maintaining cerebral perfusion usually require complex treatment. Several hybrid surgical techniques have been developed in the last decade, which combine an endovascular and open approach to obtain better results. The hybrid approach includes hybrid surgical procedures (TEVAR combined with surgical rerouting of supraaortic vessels) and the hybrid devices originating from traditional prostheses employed during open and endovascular procedures. The hybrid approach to the aortic arch is associated with less trauma, usually no need for the heart-lung-machine, no need for hypothermia or artificial cerebral perfusion, and no risk or recurrent nerve paresis. The complications related to hybrid procedures include retrograde aortic dissection type A, endoleaks, and stentgraft migration. According to the Penn classification, there are three types of hybrid approach to aortic arch pathologies [4]. Type I includes supraaortic vessels debranching using a 4 limb branched graft anastomosed to the very proximal ascending aorta (just above the sinotubular junction) and on the other side to all supraaortic vessels. The fourth branch is used to insert the stent graft in antegrade direction into the aortic arch. Type I is being performed only sporadically since it carries a relatively large risk of retrograde aortic dissection type A. Type I hybrid approach is contraindicated in case the ascending aorta diameter exceeds 3.8 cm. More popular is type II hybrid approach consisting of creating a zone 0 landing zone by replacing the ascending aorta in an open fashion and debranching the supraaortic vessels similar to type I, followed by the TEVAR procedure [5]. Its main advantage is that it is not associated with the risk of retrograde dissection. However, it necessitates sternotomy and the heart-lung-machine. Penn type III hybrid approach is a frozen-elephant-trunk procedure that includes total aortic arch replacement and stentgraft implantation in the proximal descending thoracic aorta using a hybrid prosthesis. Total endovascular arch replacement is now feasible, and two similar devices are already available. Both include one main stent graft specifically for implantation starting in the ascending and ending in the proximal thoracic descending aorta (Fig. 1). Both have 2 internal tunnels (inner branches) that are extended with stent grafts into the brachiocephalic trunk and the carotid artery. This operation requires prior carotid-subclavian bypass on the left side [6]. The ascending aorta diameter should not exceed 3.8 cm. Fig. 1 Double inner branched stent graft in the aortic arch of the patient with penetrating atherosclerotic ulcer. A – aortic stent graft, B – brachiocephalic trunk, C – left carotid artery, D – carotid-subclavian bypass The open-surgical approach to the aortic arch is the gold standard. Further development of less invasive endovascular treatment options is mandatory, since they may be beneficial for older patients with significant comorbidities who may not tolerate prolonged cross-clamp and circulatory arrest times. Transcatheter aortic valve implantation technology has not reduced the number of conventional aortic valve replacement procedures. Similarly, although endovascular aortic arch replacement is not likely to replace open surgery, it will expand our armamentarium and enable us to recruit new patients undergoing medical treatment only due to their excessive risk of conventional arch replacement.

Long-Term Changes in Aortic Length after Thoracic Endovascular Aortic Repair

PurposeTo study long-term changes to the thoracic aorta following thoracic endovascular aortic repair (TEVAR) for treatment of different aortic pathologic conditions. Materials and MethodsThis retrospective study included 53 consecutive patients (mean age, 58.8 y ± 14; 13 female and 40 male) in whom TEVAR was performed between October 2002 and May 2010. The mean duration of follow-up was 21.1 months (range, 0.5–96 mo). Statistical analysis was performed with the Friedman test and Conover–Iman test. ResultsNineteen patients with aortic aneurysm (group 1), 25 patients with type B dissection (group 2), and 9 patients with other pathologic conditions (group 3) were treated with TEVAR. The mean overall aortic lengths (from the origin of the left subclavian artery to the origin of the celiac trunk) before TEVAR were 271.4 mm, 268.6 mm, and 233.6 mm in groups 1, 2, and 3, respectively. At 12-month follow-up, the lengths were 282.8 mm, 294.4 mm, and 237.5 mm in groups 1, 2, and 3, respectively. The changes in aortic lengths following TEVAR were statistically significant (P < .001). A second intervention was required in 14 patients, and 6 patients died during follow-up. ConclusionsA significant change in the overall aortic length was observed following TEVAR. The changes in aortic length reached statistical significance after 12 months.

Aorta-to-arm pulse wave transit time ratio: Better prediction of coronary artery disease and stroke than pulse wave velocity

The major limitation of carotid-femoral pulse wave velocity (cfPWV) is the less accurate and non-standardized method of measuring the pulse wave travel length along the aorta. Many researchers used different methods and devices to measure the travel length [ 1 Laurent S. Cockcroft J. Van Bortel L. Boutouyrie P. Giannattasio C. Hayoz D. et al. Expert consensus document on arterial stiffness: methodological issues and clinical applications. Eur. Heart J. 2006; 27: 2588-2605 Crossref PubMed Scopus (4465) Google Scholar , 2 Huybrechts S.A. Devos D.G. Vermeersch S.J. Mahieu D. Achten E. de Backer T.L. et al. Carotid to femoral pulse wave velocity: a comparison of real travelled aortic path lengths determined by MRI and superficial measurements. J. Hypertens. 2011; 29: 1577-1582 Crossref PubMed Scopus (96) Google Scholar ]. The different methods used to measure travel length may influence the absolute value of pulse wave velocity, which made it difficult to compare studies. The variances of measured pulse wave travel length resulted in a significant difference in cfPWV [ [3] Rajzer M.W. Wojciechowska W. Klocek M. Palka I. Brzozowska-Kiszka M. Kawecka-Jaszcz K. Comparison of aortic pulse wave velocity measured by three techniques: complior SphygmoCor and Arteriograph. J. Hypertens. 2008; 26: 2001-2007 Crossref PubMed Scopus (245) Google Scholar ]. Furthermore, the contour of the body and a tortuous aorta may influence the measurement of real travel length. We hypothesized that the power of pressure wave analysis would be improved if pulse wave pass lengths were not used, and we evaluated the power of aorta-to-arm (carotid–femoral to carotid–radial) pulse wave transition time ratio (PWTTR) in the prediction of patients with cardiovascular disease (CVD). Corrigendum to “Aorta-to-arm pulse wave transit time ratio: Better prediction of coronary artery disease and stroke than pulse wave velocity” [International Journal of Cardiology 204 (2016), 1–3]International Journal of CardiologyVol. 217PreviewThe authors would like to apologise for any inconvenience caused. Full-Text PDF

Endograft Shortening During Endovascular Repair of Abdominal Aortic Aneurysms in Severe Aortoiliac Tortuosity

Severely tortuous aortoiliac anatomy can influence the deployment of the endograft during endovascular abdominal aortic aneurysm repair (EVAR) and have a negative impact on distal fixation. The purpose of this study was to determine how severe aortoiliac tortuosity can change an aortic endograft's length and how it affects distal fixation. A retrospective review of a prospectively collected vascular surgery database at a university-affiliated medical center was used to identify the study patients. The goal was to identify patients who underwent EVAR with the main body device deployed to a severely tortuous iliac artery. Severe aortoiliac tortuosity was defined as aortoiliac or iliac angulation of <90°. Patients were excluded if more than one device was deployed distal to the main body device, which made accurate lengths measurements difficult. A total of 469 patients underwent EVAR between 2008 and 2014. Of the 171 patients with severe aortoiliac tortuosity, in only 18 patients was the main body placed on the side of severe tortuosity without an extension limb. The mean length of the main body for EVAR was 169 mm, and this length significantly shortened to 147 mm once it was placed in the severely tortuous AAA (P < .001). Treatment length of the main body side measured from the lowest renal artery to the iliac bifurcation also significantly shortened from 179 mm to 170 mm (P = .001). The most angulated portion of the artery on the main body side became significantly less post-EVAR, changing from 86° to 114° (P < .001). Analysis of the nontortuous side showed a nonsignificant change in treatment length (P = .859) and angulation (P = .195). Severe aortoiliac tortuosity can cause significant shortening of endografts, which can negatively impact distal fixation during EVAR. Consideration for a longer main body or an extension limb should be given in tortuous aneurysms.

Results of the Nellix system investigational device exemption pivotal trial for endovascular aneurysm sealing

The Nellix EndoVascular Aneurysm Sealing system (Endologix, Inc, Irvine, Calif) is a novel approach to abdominal aortic aneurysm (AAA) endovascular repair whereby biocompatible polymer is employed to exclude and to seal the AAA sac. We report 30-day results of the U.S. pivotal trial. Consecutive, eligible, consenting patients were enrolled at 29 sites in the United States and Europe. Inclusion criteria required an asymptomatic infrarenal AAA, with aortic neck length ≥10 mm and angle to the sac ≤60 degrees, aortic neck diameter of 18 to 32 mm, aneurysm blood lumen diameter ≤6 cm, common iliac artery lumen diameter of 9 to 35 mm, access artery diameter ≥6 mm, and serum creatinine level ≤2 mg/dL. Follow-up at 30 days included clinical assessment and computed tomography angiography evaluation of endoleaks and device integrity as assessed by a core laboratory. The primary safety end point is the incidence of independently adjudicated 30-day major adverse events (MAEs), with success defined as superiority with reference to the Society for Vascular Surgery open repair control group (56%). Between January and November 2014, 150 trial patients having a mean AAA diameter of 5.8 cm were enrolled and treated with the Nellix system with 100% procedural success. One early death (0.7%) occurred secondary to multisystem organ failure. All 149 surviving patients completed 30-day follow-up. There were no aneurysm ruptures, conversions, limb thromboses, stent fractures, or stent kinking. Five early MAEs occurred in four patients (2.7%) and included one death, bowel ischemia (1), renal failure (2), and respiratory failure (1). One (0.7%) secondary intervention to treat inadvertent coverage of a renal artery was performed. The core laboratory identified nine (6%) endoleaks (one type I, eight type II) on 30-day computed tomography angiography. Freedom from MAE was 97.3% (95% confidence interval, 93.3%-99.0%). In selected patients, perioperative outcomes with the Nellix system for endovascular aneurysm sealing are encouraging, with very low 30-day morbidity and mortality and high procedural success. The primary safety end point has been achieved. Longer term follow-up is in progress.