Aortic Length Research Articles

Neuroprotective Strategies Can Prevent Permanent Paraplegia in the Majority of Patients Who Develop Spinal Cord Ischaemia After Endovascular Repair of Thoracoabdominal Aortic Aneurysms

Spinal cord ischaemia (SCI) following endovascular thoracoabdominal aortic aneurysm (TAAA) repair is a devastating and unpredictable complication. This study describes a single unit's experience of SCI in patients who have had endovascular TAAA repair. A prospectively maintained database of patients having endovascular TAAA repair using branched and fenestrated stent grafts between 2008 and 2014 at a single high volume centre was reviewed. Patients who developed neurological symptoms and signs related to SCI were identified and factors associated with onset and recovery of neurology were analysed. Sixty-nine patients (median age 73 years, 52 male; Crawford classification type I [n=4], type II [n=11], type III [n=33], type IV [n=14], type V [n=7]) underwent endovascular TAAA repair. Twelve patients developed neurological symptoms/signs related to SCI but this was successfully reversed in eight patients, leaving four (5.8%) with permanent paraplegia. The median length of aorta covered was not significantly different in the 12 patients who developed SCI compared with the cohort that did not. Eleven of the patients who developed SCI had an intraoperative mean arterial pressure (MAP) below 80mmHg. Cutaneous atheroemboli were noted in half of the patients in the SCI group compared with 11% of the non-SCI group (p<.05). Strategies used to reverse SCI included raising MAP, cerebrospinal fluid drainage, angioplasty of stenosed internal iliac arteries, and restoring perfusion to the aneurysm sac. This series highlights some of the risk factors associated with the development of SCI after endovascular repair of TAAAs. It also illustrates the importance of a dedicated institutional protocol aimed at ensuring the early diagnosis of SCI and prompt intervention to reverse permanent paraplegia in the majority of cases.

Tissue expander stimulated lengthening of arteries (TESLA) induces early endothelial cell proliferation in a novel rodent model

BackgroundWe examine the mechanism of aortic lengthening in a novel rodent model of tissue expander stimulated lengthening of arteries (TESLA). MethodsA rat model of TESLA was examined with a single stretch stimulus applied at the time of tissue expander insertion with evaluation of the aorta at 2, 4 and 7day time points. Measurements as well as histology and proliferation assays were performed and compared to sham controls. ResultsThe aortic length was increased at all time points without histologic signs of tissue injury. Nuclear density remained unchanged despite the increase in length suggesting cellular hyperplasia. Cellular proliferation was confirmed in endothelial cell layer by Ki-67 stain. ConclusionsAortic lengthening may be achieved using TESLA. The increase in aortic length can be achieved without tissue injury and results at least partially from cellular hyperplasia. Further studies are required to define the mechanisms involved in the growth of arteries under increased longitudinal stress.

Topographic Anatomy as a Surrogate Measure of Aortic Length for Resuscitative Endovascular Balloon Occlusion of the Aorta Catheter Insertion

Topographic Anatomy as a Surrogate Measure of Aortic Length for Resuscitative Endovascular Balloon Occlusion of the Aorta Catheter Insertion

Aortic Arch Morphology and Aortic Length in Patients with Dissection, Traumatic, and Aneurysmal Disease

To assess aortic arch morphology and aortic length in patients with dissection, traumatic injury, and aneurysm undergoing TEVAR, and to identify characteristics specific to different pathologies. This was a retrospective analysis of the aortic arch morphology and aortic length of dissection, traumatic injury, and aneurysmal patients. Computed tomography imaging was evaluated of 210 patients (49 dissection, 99 traumatic injury, 62 aneurysm) enrolled in three trials that received the conformable GORE TAG thoracic endoprosthesis. The mean age of trauma patients was 43±19.6 years, 57±11.7 years for dissection and 72±9.6 years for aneurysm patients. A standardized protocol was used to measure aortic arch diameter, length, and take-off angle and clockface orientation of branch vessels. Differences in arch anatomy and length were assessed using ANOVA and independent t tests. Of the 210 arches evaluated, 22% had arch vessel common trunk configurations. The aortic diameter and the distance from the left main coronary (LMC) to the left common carotid (LCC) were greater in dissection patients than in trauma or aneurysm patients (p<.001). Aortic diameter in aneurysm patients was greater compared with trauma patients (p<.05). The distances from the branch vessels to the celiac artery (CA) were greater in dissection and aneurysm patients than in trauma patients (p<.001). The take-off angle of the innominate (I), LCCA, and left subclavian (LS) were greater, between 19% and 36%, in trauma patients than in dissection and aneurysm patients (p<.001). Clockface orientation of the arch vessels varies between pathologies. Arch anatomy has significant morphologic differences when comparing aortic pathologies. Describing these differences in a large sample of patients is beneficial for device designs and patient selection.

Modified closing-opening wedge osteotomy for the treatment of sagittal malalignment in thoracolumbar fractures malunion

Background ContextMany techniques have been described for the surgical treatment of rigid posttraumatic thoracolumbar kyphosis, but none is well adapted to the modified shape of the wedged vertebra. PurposeThe study aimed to describe the modified closing-opening wedge osteotomy (MCOWO), a new osteotomy technique that adapts to the triangular shape of the wedged apical vertebra of the deformity. Study DesignA retrospective assessment of the degree of correction before and after the MCOWO was carried out. Patient SampleTen patients presenting rigid posttraumatic thoracolumbar kyphosis were enrolled in this study. Outcome MeasuresWe used preoperative and postoperative whole spine radiographs to assess the sagittal plane parameters, and computed tomography scan for measurement of the vertebral segment height at the osteotomy level, spinal cord length, aorta length, and fusion rate. MethodsTen patients underwent the MCOWO at T12 or L1. The procedure involves removing the postero-superior triangular corner of the wedged vertebra and transforming it to a shape similar to a trapezoid. ResultsThe patients' mean age was 36.6±7.5 years, the mean time between the fracture and the surgery was 12.2±5.6 months, and the mean follow-up was 30.6±5 months. In all patients, statistically significant improvement was observed in the sagittal plane after surgery. The thoracolumbar angle improved from 52±6° preoperatively to 7.1±5.7° at the last follow-up. Mean osteotomy angle was 38.1±2.6°, mean spinal cord shortening was 1.2±0.2 cm, and mean aorta lengthening was 2.3±0.4 cm. All the patients showed complete fusion at 2 years, and none required revision surgery. Two patients presented a temporary unilateral weakness that recovered completely within 3 months after the surgery. ConclusionsThe MCOWO is an interesting procedure for patients with posttraumatic thoracolumbar kyphosis. The modified osteotomy is adapted to the modified shape of the compressed vertebra. Spinal cord shortening and aorta lengthening were well tolerated in all patients.

Trends in Endovascular Aortic Aneurysm Repair Length of Stay over a Decade at a Tertiary Academic Institution

Length of stay (LOS) is used as a quality metric to reduce cost and improve value of delivery of care. We sought to analyze trends in endovascular aortic aneurysm repair (EVAR) LOS at a tertiary academic institution over the last decade. A retrospective review of prospectively collected data was performed. Infrarenal EVARs from 2001 to 2013 were divided into 3 groups: group I (2001-2004), EVARs were performed as part of clinical trials; group II (2005-2008), EVARs were referred to a tertiary referral center with the most experience with EVAR; group III (2009-2013), EVARs were referred to academic institutions in the presence of severe patient comorbidities. Trends in LOS and correlation with severity of illness (SOI) as based on All Patient Refined Diagnosis Related Groups and admission and/or disposition status were analyzed. LOS index (LOSI) at our institution was then compared with University HealthSystem Consortium (UHC) Hospitals over the past 3 years. A total of 1,265 EVARs were performed during this time period: 325 in group I, 547 in group II, and 393 in group III. The median LOS was 4 days (inter quartile range [IQR], 2-6) vs. 3 days (IQR, 2-5) ± 0.28 vs. 4 days (IQR, 3-7), respectively (P < 0.01). Although moderate SOI was fairly constant over time (P = 0.66), major and/or extreme SOI constituted a greater proportion of patients in group I, was reduced in group II, and was again increased in group III, P < 0.01. The complication rate paralleled this pattern (group I, 15.2%; group II, 8.6%; group III, 10.4%; P = 0.02). The percentage of patients discharged to nursing home and/or rehab was 5.7% in group I, 8.2% in group II, 11.5% in group III (P = 0.03). Cases that were performed urgently and/or emergently increased over time: 11.6% in group I, 14.9% in group II, 21.6% in group III (P = 0.01). The risk-adjusted LOSI at our institution was significantly greater (1.25) when compared with UHC hospitals (0.75). Our study suggests a relationship between time period of EVAR, SOI, complications, admission status, and LOS. Attention to these trends could be used to decrease LOS in an increasingly complex patient population.

Endovascular repair of Stanford B aortic dissection using two stent grafts with different sizes

The objective of this study was to introduce a novel strategy for thoracic endovascular aortic repair of Stanford B aortic dissection using two-stent graft implantation (TSI), in which the proximal stent and distal stent with different sizes are sequentially deployed, and to summarize our experience with this technique. A retrospective study was conducted of 72 consecutive patients (61 men; mean age, 55 ± 7 years; range, 41-67 years) with Stanford type B aortic dissection who underwent TSI treatment between January 2012 and May 2013. Among all patients, 43 (59.7%) involved the infrarenal aorta and 29 (40.3%) involved the whole thoracic and abdominal aorta; mean aortic involvement length was 226 ± 13 mm (range, 182-312 mm). Eight cases were for acute dissection (within 2 weeks from onset of symptoms), 11 cases were for chronic dissection (>3 months after initial dissection), and 53 cases were for subacute dissection (between 2 weeks and 3 months). Twenty-two cases (30.6%) were uncomplicated type and 50 cases (69.4%) were complicated type. Follow-up was performed postoperatively at 1 month, 6 months, and yearly thereafter. Technique success, aorta morphology, and procedure-related complications were evaluated. Technical success was achieved in 100%; 72 pairs of stent grafts (144 thoracic stent grafts) and 10 left subclavian artery chimney stents were used. The mean aortic length coverage by the stent grafts was 197.6 ± 20.3 mm, and mean taper diameter span was 7.5 ± 1.8 mm. All patients were followed up from 6 to 16 months (mean, 10 ± 4 months); 95.8% (69 of 72) had a thrombosed false lumen in the aortic coverage, and the true lumen expanded on average 57% ± 11% (23%-100%). No significant changes were found in aortic diameters of the proximal and distal ends of the two stent grafts and the angles between centerlines of the distal end of the stent and the aorta during follow-up. Procedure-related complications included transient paraplegia (coverage of the left subclavian artery without revascularization and extensive coverage of aorta >220 mm) due to acute spinal cord ischemia (n = 1) and malapposition of the distal stent (primary tear closed, true lumen expansion led to oversize rate insufficient in distal stent diameter; n = 1). No death or malperfusion complications were observed during the perioperative period and follow-up. Short-term outcomes showed TSI to be a flexible and effective approach to accurately repair Stanford B aortic dissection that could potentially address the limitations of currently available stent grafts. Further prospective clinical studies are warranted to evaluate its long-term efficacy.

Immediate Change in Suprarenal Neck Angulation After Endovascular Aneurysm Repair

Purpose: To compare the immediate suprarenal neck angulation change between the Ovation stent-graft, with its inflatable sealing rings, and a stent-graft with a conventional sealing mechanism. Methods: A case-control study was conducted in which 30 consecutive patients (mean age 67 years; all men) with abdominal aortic aneurysm (AAA) treated with the Ovation stent-graft (group O) were retrospectively compared with 24 patients (mean age 77 years; all men) contemporaneously treated with the Endurant stent-graft (group E) at 3 high-volume tertiary vascular centers. The variables recorded were the aortic neck length, preoperative and postoperative angulation, minimum and maximum diameters of the infrarenal neck, as well as the maximum AAA diameter. All patients had undergone preoperative and postoperative (within 30 days) computed tomographic angiography. Multiple regression analysis compared the relative contribution to neck angulation change of each geometric parameter and the type of endograft. Data are presented as the mean ± standard deviation. Results: The mean preoperative suprarenal neck angulation in group O was 23.2°±18.0° compared with 23.8°±22.9° in group E (t test, p=0.91). The neck lengths were 29.2±14.6 and 23.2±11.0 mm in groups O and E, respectively (p=0.1). Similarly, the minimum and maximum neck diameters were 22.4±2.6 and 25±3.5 mm, respectively, in group O vs 23.3±3.6 mm and 27.0±5.7 mm, respectively, in group E (p=0.3 and 0.12, respectively). The maximum transverse diameters of the AAA in the 2 groups were comparable, that is, 57.0±9.0 mm in group O vs 53.2±11.1 mm in group E (p=0.17). The Ovation stent-graft caused greater decrease in the aortic neck angulation postoperatively compared with the Endurant device (13.2°±16.1° vs 6.1°±5.9°, p=0.04). Multiple regression analysis revealed that preoperative neck angulation (β coefficient 0.37, p<0.001) and the type of endograft (β coefficient −7.91, p=0.01) had significant influence on the postoperative neck angulation change. The intraclass correlation coefficient ranged from 0.951 to 0.990 for the preoperative measurements and from 0.911 to 0.999 for the postoperative measurements for each examiner or the total of estimates at the measurement time points. Conclusion: The Ovation stent-graft induces greater postoperative reduction in the AAA neck angulation compared to an endograft with stent-supported graft seal. Expanded research to infrarenal angle as well to greater angles and correlation to clinical events is justified.

Late aortic remodeling persists in the stented segment after endovascular repair of acute complicated type B aortic dissection

Thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissection (AD) promotes early positive aortic remodeling. However, little is known about the long-term effect of TEVAR on the dissected aorta, which is the goal of this study. Between August 2005 and August 2009, 31 patients with complicated type B AD were treated with TEVAR and had >1-year follow-up imaging. Computed tomography angiograms obtained at 1 month, 1 year, and long term (average, 42 months) were compared with baseline scans. The largest diameters of the stented thoracic aorta, stented true lumen, and stented false lumen were recorded at each time point, as were the values in the unstented distal thoracic aorta and the abdominal aorta. Changes over time were evaluated by a mixed effect analysis of variance model of repeated measures. The average age of the cohort was 56 years, and 74% were male. Indications for TEVAR were as follows: 61% malperfusion, 32% refractory hypertension, 45% impending rupture, and 32% persistent pain; 58% had more than one indication. All patients were treated in the acute phase within 7 days of the initial presentation. The average length of aorta covered was 19 cm. Observation of the stented segment over time showed that the maximum diameter of the stented thoracic aorta was stable (P = NS), the diameter of the stented true lumen increased (P < .001), and the diameter of the stented false lumen decreased (P < .001); 84% had complete false lumen obliteration across the stented aortic segment. Observation of the uncovered thoracic aorta over time showed that the maximum diameter increased (P = .014), as did the visceral segment of the aorta (P < .001). The average growth of the visceral segment was 31% in patients with a patent false lumen vs 3% in those with a thrombosed false lumen (P = .004). One patient had aneurysmal degeneration of the false lumen and required an additional endograft at 18 months. TEVAR of acute AD promotes long-term remodeling across the stented segment, with false lumen obliteration in 84% of patients. However, false lumen obliteration beyond the stented segment appears necessary to prevent late aneurysmal degeneration of the distal aorta.

SS10. Endovascular Treatment of Failed Open Surgical and Bifurcated Stent Grafts and Short-Length Infrarenal Aortic Aneurysms Using Fenestrated-Branched Endografts With Distal Inverted Iliac Limbs

Objectives: Open aortoiliac grafts have been constructed with a short aortic bifurcation sewn near or to the visceral vessels to avoid limb kinking. Similarly, the majority of endovascular bifurcated stent grafts have short aortic main body ranging from 4 to 5 cm. In these patients and in those with short infrarenal aortic lengths, endovascular salvage with fenestrated-branched stent grafts is technically challenging because of the short distance between the renal arteries and the flow divider of the graft. Custom-manufactured fenestrated-branched stent grafts can be extended into the prior open surgical graft or stent graft using a short distal bifurcated stent graft with inverted iliac limb (Fig) for the contralateral gate. The aim of this study was to evaluate outcomes of patients treated with fenestrated-branched stent grafts coupled with inverted iliac limbs for salvage of failed open surgical and endovascular stent grafts. Methods: The clinical data of three high-volume, complex aortic referral centers using fenestrated-branched stent grafts were entered into prospectively maintained databases from January 2011 to June 2014. All patients had investigational manufactured devices under physician-sponsored investigational device exemption protocols. In addition to the proximal fenestrated-branched component, all patients received custom-manufactured distal bifurcated devices constructed with a main body<70 mm and an inverted iliac limb to dock the contralateral gate. End points were technical success, 30-day or in-hospital mortality, type I or III endoleak, limb occlusion, and secondary reintervention. Results: There were 56 patients, 41 males (73%) and 15 females (27%), with mean age of 75 years (range, 5986 years) treated by fenestrated-branched stent grafts using distal bifurcated devices with inverted iliac limbs. Fortyseven patients (84%) had a previous aortic repair with a short main body device and nine had short distances between the native renal artery and aortic bifurcation requiring inverted limbs. A total of 184 visceral arteries were targeted by fenestrations or branches (mean, 3.3 vessels/patient). Technical success was 96.4%, with no 30-day or in-hospital deaths. At a mean follow-up of 11 months, six patients developed endoleaks; however, there were no device migration, occlusions, or complications associated with the inverted limb. On the inverted limb side there were three complications. Two patients developed type IB endoleaks treated by limb extension and angioplasty, and one patient developed distal limb ischemia treated by thrombectomy. Reintervention was successful in all of these patients. Conclusions: Patients with a short distance between the renal arteries and the aortic bifurcation can be challenging for endovascular treatment using currently available devices. The use of inverted limb custom-manufactured devices avoids the need for aortouniiliac repair, with femoralfemoral bypass preserving antegrade contralateral limb perfusion. The device was associated with no migration, component separations, or type III endoleaks. In the short-term, rates of type III endoleak or limb occlusion are similar to what has been reported for universal bifurcated devices with noninverted iliac limbs.

49. Gender Differences In Aortic Neck Morphology In Patients With Abdominal Aortic Aneurysms Undergoing EVAR

Introduction and Objectives: Prior studies have alluded to gender differences in aortic neckmorphology resulting in anatomic exclusion of some women from EVAR. The objective of this study is to correlate gender differences in aortic neck morphology and changes in the neck and aneurysm sac after EVAR. Methods: A retrospective review of consecutive EVARs performed for infrarenal AAA was conducted from 2004 to 2013 at a single institution. Preand post-operative imaging studies were utilized to measure aortic neck length and diameter, shape, and angulation, aneurysm sac diameter. Volumetric analysis of neck thrombus burden was performed using TeraRecon . Results: 146 patients met inclusion criteria 21% were women with a mean age of 75.5 (p1⁄40.724) with comparable baseline comorbidities to men. Neck angulation was greater in women 23.9 vs 13.5 (P<0.028). The percent thrombus of the aortic neck was greater in female patients at 35.7% vs 30%(P1⁄40.02). Preoperative AAA diameter

Urgent endovascular repair for ruptured aortic aneurysm using computed tomography image fusion

Abdominal aortic aneurysm rupture remains a cardiovascular catastrophe with strikingly high morbidity and mortality rates. Endovascular aneurysm repair management has recently emerged as a valuable treatment modality for ruptured abdominal aortic aneurysm, but better outcomes have to be reached. Image fusion may potentially improve perioperative outcomes in selected patients, guiding navigation and device implantation and limiting contrast dosage during interventions. We report an 83-year-old man presenting with an 80-mm infrarenal aortic aneurysm rupture suitable for endovascular aneurysm repair. Endovascular navigation and stent graft deployment were achieved using computed tomography image fusion for the first reported case in English.

0368 : Aortic impedance in older subjects: MR and applanation tonometry study by wave intensity analysis

Central pressure waveform can be decomposed into pressure transmission and reflection waves. Zc, characteristic impedance of aorta can be measured through the recording of pulse pressure and aortic flow signals and reflects structural and functional properties of elastic central and peripheral muscular arteries. This study proposes a novel method using wave intensity analysis to assess reflected waves by decomposition of magnetic resonance imaging central aortic flow and central aortic pressure waveform measured by tonometry in 30 older subjects allowing to obtain the aortic characteristic impedance in the time domain and reflection index (IR) and reflection magnitude (MR). Elderly patients were mean aged of 75.25±5.85 years (14 female, 16 male). Mean Zc value was 424.34±94.41 DSC for the whole aging population. We found a strong negative association between Zc and LVET (r=–0.53, p=0.004). We found also a trend of negative association between Zc and aortic diameter, at the aortic root, (r=–0.36, p=0.05), and pressure augmentation (r=–0.36, p=0.06), and also with Aix (r = –0.32, p=0.09). Zc was positively associated with PPA (r = 0.41, p=0.02), and also strongly with HR (r= 0.54, p=0.003). Association between RM and IR were positively significant with aorta length measure by MRI, respectively (r=0.41, p=0.03) for RM and (r=0.42, p=0.03) for IR. RM associated positively with thoracic aorta length (r2 = 0.15, p=0.04) after adjustment to age and height, IR also associated positively with thoracic aorta length (r2 = 0.16, p=0.04) after adjustment to age and height. This automatic signal treatment of aortic flow and pulse pressure waveform is a good method for assessment of wave reflections in older subjects allowing obtaining reflection magnitude. Aortic characteristic impedance is inversely correlated to left ventricular ejection time and aortic diameter as new insights suggest.

Aortoiliac Elongation after Endovascular Aortic Aneurysm Repair

Aortoiliac elongation after endovascular aortic aneurysm repair (EVAR) is not well studied. We sought to assess the long-term morphologic changes after EVAR and identify potentially modifiable factors associated with such a change. An institutional review board-approved retrospective review was conducted for 88 consecutive patients who underwent EVAR at a single academic center from 2003 to 2007 and who also had at least 2 follow-up computed tomography angiograms (CTAs) available for review up to 5 years after surgery. Standardized centerline aortic lengths and diameters were obtained on Aquarius iNtuition 3D workstation (TeraRecon Inc., San Mateo, CA) on postoperative and all-available follow-up CTAs. Relationships to aortic elongation were determined using Wilcoxon rank-sum test or linear regression (Stata version 12.1, College Station, TX). Changes in length over time were determined by mixed-effects analysis (SAS version 9.3, Cary, NC). The study cohort was composed of mostly men (88%), with a mean age of (76 ± 8) and a mean follow-up of 3.2 years (range, 0.4-7.5 years). Fifty-seven percent of patients (n = 50) had devices with suprarenal fixation and 43% (n = 38) had no suprarenal fixation. Significant lengthening was observed over the study period in the aortoiliac segments, but not in the iliofemoral segments. Aortoiliac elongation over time was not associated with sex (P = 0.3), hypertension (P = 0.7), coronary artery disease (P = 0.3), diabetes (P = 0.3), or tobacco use (P = 0.4), but was associated with the use of statins (P = 0.03) and the presence of chronic obstructive pulmonary disease (P = 0.02). Significant aortic lengthening was associated with increased type I endoleaks (P = 0.03) and reinterventions (P = 0.03). Over the study period, 4 different devices were used; Zenith (Cook Medical Inc., Bloomington, IN), Talent (Medtronic, Minneapolis, MN), Aneuryx (Medtronic), and Excluder (W. L. Gore and Associates Inc., Flagstaff, AZ). After adjusting for differences in proximal landing zone, significant differences in aortic lengthening over time were observed by device type (P = 0.02). Significant aortoiliac elongation was observed after EVAR. Such morphologic changes may impact long-term durability of EVAR, warranting further investigation into factors associated with these morphologic changes.

Outcome-based anatomic criteria for defining the hostile aortic neck

There is abundant evidence linking hostile proximal aortic neck anatomy to poor outcome after endovascular aortic aneurysm repair (EVAR), yet the definition of hostile anatomy varies from study to study. This current analysis was undertaken to identify anatomic criteria that are most predictive of success or failure at the aortic neck after EVAR. The study group comprised 221 patients in the Aneurysm Treatment using the Heli-FX Aortic Securement System Global Registry (ANCHOR) clinical trial, a population enriched with patients with challenging aortic neck anatomy and failure of sealing. Imaging protocols were not protocol specified but were performed according to the institution's standard of care. Core laboratory analysis assessed the three-dimensional centerline-reformatted computed tomography scans. Failure at the aortic neck was defined by type Ia endoleak occurring at the time of the initial endograft implantation or during follow-up. Receiver operating characteristic curve analysis was used to assess the value of each anatomic measure in the classification of aortic neck success and failure and to identify optimal thresholds of discrimination. Binary logistic regression was performed after excluding highly intercorrelated variables, creating a final model with significant predictors of outcome after EVAR. Among the 221 patients, 121 (54.8%) remained free of type Ia endoleak and 100 (45.2%) did not. Type Ia endoleaks presented immediately after endograft deployment in 58 (58.0%) or during follow-up in 42 (42.0%). Receiver operating characteristic curve analysis identified 12 variables where the classification of patients with type Ia endoleak was significantly more accurate than chance alone. Increased aortic neck diameter at the lowest renal artery (P = .013) and at 5 mm (P = .008), 10 mm (P = .008), and 15 mm (P = .010) distally; aneurysm sac diameter (P = .001), common iliac artery diameters (right, P = .012; left, P = .032), and a conical (P = .049) neck configuration were predictive of endoleak. By contrast, increased aortic neck length (P = .050), a funnel-shaped aortic neck (P = .036), and neck mural thrombus content, as measured by average thickness (P = .044) or degrees of circumferential coverage (P = .029), were protective against endoleak. Binary logistic regression identified three variables independently predictive of type Ia endoleak. Neck diameter at the lowest renal artery (P = .002, cutpoint 26 mm) and neck length (P = .017, cutpoint 17 mm) were associated with endoleak, whereas some mural neck thrombus content was protective (P = .001, cutpoint 11° of circumferential coverage). A limited number of independent anatomic variables are predictive of type Ia endoleak after EVAR, including aortic neck diameter and aortic neck length, whereas mural thrombus in the neck is protective. This study suggests that anatomic measures with identifiable threshold cutpoints should be considered when defining the hostile aortic neck and assessing the risk of complications after EVAR.

The compatibility of p-branch “off-the-shelf” fenestrated endovascular graft in Asian patients with juxtarenal aortic aneurysm

The Zenith pivot branch (p-branch) fenestrated endovascular graft (Cook Medical, Bloomington, Ind) is a new "off-the-shelf" device to treat patients with juxtarenal aortic aneurysms (JRAs). Two options are currently available, which appear to suit >70% of white patients. This study investigates the anatomic applicability of the p-branch fenestrated graft in a cohort of Asian patients with JRA. Computed tomography images of 51 consecutive Asian patients with JRA (43 men; mean age, 76.8 years) were analyzed on an Aquarius workstation (TeraRecon, San Mateo, Calif) and matched to two current configurations of the p-branch (options A and B: single superior mesenteric artery [SMA] and two renal fenestrations, and a celiac axis scallop). With use of the SMA as reference, the anatomic positions of both renal arteries and the celiac axis were figured together with their diameters on a template generated on MATLAB (MathWorks, Natick, Mass), and then they were matched with two graft configurations. The renal artery origins were assessed for three classes of "closeness of fit" based on diameter: perfect match, marginal match, and mismatch, respectively, defined as the renal artery origins being located entirely inside, partially inside, and completely outside their corresponding fenestrations. The suitability of the p-branch graft design to the aneurysms was then evaluated. A total of 31 JRA patients (60.8%) were regarded as suitable candidates for one or both p-branch stent grafts (20 with option A, 22 with option B, and 11 with both options). In 35 patients (68.6%), both renal arteries could be aligned with the fenestrations. Among them, 16 patients (31.4%) were perfectly matched, whereas 19 patients (37.2%) were only marginally suitable. The major reason for exclusion was the misalignment of the renal fenestrations. In 16 patients with unsuitable renal fenestrations, 8 were attributed to the right renal origins being located too distally compared with their corresponding fenestrations. Another reason for exclusion was the position of the celiac axis scallop in four patients (7.84%), and insufficient aortic length for the graft was encountered in another four. If the right renal fenestration of option B was adjusted to 20 mm caudal to the SMA fenestration (level with the left fenestration), the match of renal fenestration could reach 78.4% (40 of 51). The present design of the p-branch off-the-shelf fenestrated graft is feasible for a good proportion of JRA patients in Asia. Further refinement of design may improve the anatomic match, especially a lower right renal artery origin.

Chronic aortic root pressure-loading assessment model.

Percutaneous placement of transcatheter prosthetic aortic valves without cardiopulmonary bypass (CPB) continues to gain clinical acceptance. However, information on pressure-loading characteristics of the aortic root/annular areas is limited. For this reason, we designed a preclinical model, implanting an aortic root load transducer with a power source/telemetry system for chronic, conscious, loading data acquisition. This research study was conducted to determine whether an animal model could accurately measure in vivo loading. Preoperatively, echocardiography and magnetic resonance imaging were used to determine both aortic annular and sinotubular junction dimensions, as well as ascending aortic length. Six adult sheep were placed on CPB, aortic root and ascending aorta were skeletonized and the origins of both coronary ostia were identified. Cardiac arrest with myocardial protection with cold coronary blood cardioplegia was instituted. A properly sized aortic root load-sensing device, consisting of a transcatheter aortic valve with a ring load transducer was implanted via a left apical ventriculotomy. Verification of position was determined before closure of the ventriculotomy. Each animal was weaned from CPB, and closed in routine fashion with the power source of the device placed in a subcutaneous pocket. There were no operative deaths or significant postoperative complications. Serial pressure-load sensing assessments in a conscious state produced reproducible proprietary data. This animal model allowed successful serial pressure-load sensing assessment of the aortic root/annular areas, providing a better physiological understanding of these anatomical inter-relationships. This added information could aid in future device designs with potential improved clinical outcomes.

IABP ballooning in chinese patients

Introduction: The ischaemic disorders as a complication of intra-aortic balloon pump counterpulsation (IABP) could be deleterious in critically ill patients with myocardial failure and cardiogenic shock. Tis study is a pilot to predict the length of the descending aorta to select the optimum IABP size for Asian patients. Methods: The somatometric features from 80 Chinese patients were used: gender, age, height, body mass index, body surface area, trans-pyloric plane. Moreover, the aortic length from the origin of left subclavian artery to the orifice of the celiac trunk (LSA-CT) measured from tomographic scan examination. The variables to predict the length from the LSA-CT were studied in four types of predictive statistical analysis: nonlinear regression analysis, tree model, linear regression, and loglinear regression. The model was defined by obtaining the R square. Results: Tere were 59 males (mean age 53.9 years SD 13.2, height 170.8cm SD 4.0) and 21 females (mean age 58.7 years SD 7.8, height 160.2 cm SD 6.8). LSA-CT distance was found to be 279.5 SD 31.34 mm. The length of distance from the jugular notch to trans-pyloric plane was 273.8cm SD 12.5. The body mass index was 25.6 Kg/m2 SD 3.8 and the body surface area 1.8 m2 SD 0.1. The tree model for predicting the distance to the left subclavian artery to the celiac axis was chosen due to obtained an R2 square of 0,829. The comparison between the tomographic values and results of the tree model was realized with a nonparametric test. Wilcoxon signed-rank test showed that the values of computed tomograhy scan did not show a statistically significant difference with the results of the tree model (Z = -0.827 p =0.408). Conclusion: The tree model for predicting the distance from the left subclavian artery to the celiac trunk, could be an accurate guide to choosing an adequate catheter length of intra-aortic balloon pump counterpulsation in Asian patients.

Aortic Arch Morphology and Aortic Length in Patients with Dissection, Traumatic, and Aneurysmal Disease

Aortic Arch Morphology and Aortic Length in Patients with Dissection, Traumatic, and Aneurysmal Disease

Endoleak Outcomes of Suprarenal vs. Infrarenal Endovascular Aneurysm Repairs Outside Instructions for Use Standards

Purpose To determine if there are any differences in outcomes between infrarenal fixation (IF) and suprarenal fixation (SF) for the endovascular treatment of abdominal aortic aneurysms (AAAs) with aortic neck lengths ( Material and Methods A retrospective review of 561 endovascular aneurysm repairs (EVAR) procedures performed from 2004 to 2011 at a single institution. The charts and radiographic images of all patients were reviewed. Patients who underwent EVAR with AAA with short proximal neck lengths were stratified into 2 groups of IF (Gore Excluder) and SF (Cook Zenith). The primary end point of the study was the presence of endoleaks. The secondary end points were graft migration, postoperative rupture, and death. Results A total of 561 EVARs were performed during this study period with 52 identified as having a short proximal aortic neck. Seventeen patients were in the IF group and 34 in the SF group. The mean follow up period was 33.9 months for the IF group and 23.4 months for the SF group. There was no difference in the average proximal neck length (8.8 mm IF vs. 9.9 mm SF; p = not significant [NS]) or the preoperative AAA size (23.7 mm IF vs. 25.2 mm SF; p = NS). There were no significant differences in age (74.7 years IF vs. 78.2 years SF; p = NS), gender (IF 94% male vs. SF 88% male; p = NS) or length of stay (2.2 days IF vs. 3 days SF; p = NS). There was one type II endoleak in both the IF and SF groups at 90-day follow up. At 1 year, the type II endoleak in the IF group persisted while the 1 patient with a type II endoleak in the SF group died. There were no migrations noted in either group. There were no ruptures in the IF group and 1 rupture in the SF group (p = NS). There were 5 deaths in the IF group and 5 deaths in the SF group (p = NS). Conclusions There was no significant difference in endoleak rates between SF and IF for patients with short aortic neck lengths outside IFU standards.