Endovascular Repair of Juxtarenal and Pararenal Abdominal Aortic Aneurysms Using a Novel Low-Profile Fenestrated Custom-Made Endograft: Technical Details and Short-Term Outcomes.

INTRODUCTION: The aim of this study is to share preliminary experiences and outcomes with a novel custom-made fenestrated TREO® Abdominal Stent-Graft System to treat juxtarenal and pararenal abdominal aortic aneurysms (AAAs). METHODS: Juxtarenal and pararenal AAA patients treated with the custom-made fenestrated TREO® Abdominal Stent-Graft System were included from 4 high-volume European academic medical centers from June 2021 to September 2023. Technical success and 30-day/in-hospital mortality and complications were analyzed. Technical success was defined as successful endovascular implantation of the stent graft with preservation of antegrade flow to the target vessels, and absence of type 1 or 2 endoleak (EL) at the first postoperative computed tomography angiography (CTA). RESULTS: Forty-two consecutive patients were included. The majority of the devices were constructed with 2 (N=4; 9.5%), 3 (N=9; 21.4%), or 4 (N=27; 64%) fenestrations. In 1 case, the device was constructed with a single fenestration (2.4%) and 1 device contained 5 fenestrations (2.4%); 17% had previous AAA repair. Target vessel cannulation with placement of a bridging stent was successful in all but 1 vessel (99, 3%). One aneurysm-related death occurred in the direct postoperative period and 2 limb occlusions necessitated reintervention during admission. In the median follow-up period of 101 (2-620) days, 3 more patients died due to non-aneurysm-related causes. Technical success was achieved in 90% of the cases. Nineteen ELs were seen on the first postoperative CT scan: 1 type 1b EL (N=1; 2%), 15 type 2 ELs (N=15; 36%), and 3 type 3 ELs (N=3%). Eleven patients received more than 1 CT scan during a median follow-up of 361 days (82-620): 3 type 2 ELs resolved and 1 type 3 EL was treated in this period. In the follow-up, 1 patient had a coagulation disorder that caused occlusions of the branches. CONCLUSION: The results of the first experiences using the custom-made fenestrated TREO® Abdominal Stent-Graft System in Europe are promising. There was a low short-term mortality and morbidity rate in these patients of which 17% had previous AAA repair. Mid-term and long-term follow-up data are needed to evaluate endograft durability and performance. CLINICAL IMPACT: This study shows the first experiences and short-term results of a novel low-profile custom-made device: the custom-made fenestrated TREO® Abdominal Stent-Graft System. Showing these results and experiences can help the physicians in clinical decision-making for their patients.

Three-Dimensional Characterization of Aortic Root Motion by Vascular Deformation Mapping.

The aorta is in constant motion due to the combination of cyclic loading and unloading with its mechanical coupling to the contractile left ventricle (LV) myocardium. This aortic root motion has been proposed as a marker for aortic disease progression. Aortic root motion extraction techniques have been mostly based on 2D image analysis and have thus lacked a rigorous description of the different components of aortic root motion (e.g., axial versus in-plane). In this study, we utilized a novel technique termed vascular deformation mapping (VDM(D)) to extract 3D aortic root motion from dynamic computed tomography angiography images. Aortic root displacement (axial and in-plane), area ratio and distensibility, axial tilt, aortic rotation, and LV/Ao angles were extracted and compared for four different subject groups: non-aneurysmal, TAA, Marfan, and repair. The repair group showed smaller aortic root displacement, aortic rotation, and distensibility than the other groups. The repair group was also the only group that showed a larger relative in-plane displacement than relative axial displacement. The Marfan group showed the largest heterogeneity in aortic root displacement, distensibility, and age. The non-aneurysmal group showed a negative correlation between age and distensibility, consistent with previous studies. Our results revealed a strong positive correlation between LV/Ao angle and relative axial displacement and a strong negative correlation between LV/Ao angle and relative in-plane displacement. VDM(D)-derived 3D aortic root motion can be used in future studies to define improved boundary conditions for aortic wall stress analysis.

The effect of menaquinone-7 supplementation on vascular calcification in patients with diabetes: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Vitamin K occurs in the diet as phylloquinone and menaquinones. Observational studies have shown that both phylloquinone and menaquinone intake might reduce cardiovascular disease (CVD) risk. However, the effect of vitamin K on vascular calcification is unknown. OBJECTIVES: The aim of this study was to assess if menaquinone supplementation, compared to placebo, decreases vascular calcification in people with type 2 diabetes and known CVD. METHODS: In this double-blind, randomized, placebo-controlled trial, we randomly assigned men and women with type 2 diabetes and CVD to 360 µg/d menaquinone-7 (MK-7) or placebo for 6 mo. Femoral arterial calcification at baseline and 6 mo was measured with 18sodium fluoride positron emission tomography (18F-NaF PET) scans as target-to-background ratios (TBRs), a promising technique to detect active calcification. Calcification mass on conventional computed tomography (CT) scan was measured as secondary outcome. Dephosphorylated-uncarboxylated matrix Gla protein (dp-ucMGP) concentrations were measured to assess compliance. Linear regression analyses were performed with either TBR or CT calcification at follow-up as the dependent variable, and treatment and baseline TBR or CT calcification as independent variables. RESULTS: We randomly assigned 35 patients to the MK-7 group (33 completed follow-up) and 33 to the placebo group (27 completed follow-up). After the 6-mo intervention, TBR tended to increase in the MK-7 group compared with placebo (0.25; 95% CI: -0.02, 0.51; P = 0.06), although this was not significant. Log-transformed CT calcification mass did not increase in the intervention group compared with placebo (0.50; 95% CI: -0.23, 1.36; P = 0.18). MK-7 supplementation significantly reduced dp-ucMGP compared with placebo (-205.6 pmol/L; 95% CI: -255.8, -155.3 pmol/L). No adverse events were reported. CONCLUSION: MK-7 supplementation tended to increase active calcification measured with 18F-NaF PET activity compared with placebo, but no effect was found on conventional CT. Additional research investigating the interpretation of 18F-NaF PET activity is necessary. This trial was registered at clinicaltrials.gov as NCT02839044.

Volumetric assessment of extracranial carotid artery aneurysms.

The extracranial carotid artery aneurysm (ECAA) is a rare pathology for which clinical treatment guidelines are lacking. In general, symptoms or growth of the aneurysm sac are thought to indicate intervention. ECAAs may present in a large variety of shapes and sizes, and conventional diameter measurements fail to indicate geometrical differences. Therefore, we propose a protocol to measure ECAA size by 3D volumetric assessment. The volumes of 40 ECAAs in computed tomography angiography (CTA) images were measured through manual segmentation, by two independent operators. Volumes of the entire internal carotid artery (ICA) and the ECAA were measured separately. Excellent inter- and intraoperator reliability was found for both ICA and ECAA volumes, with all intraclass correlation coefficients above 0.94. Bland-Altman analysis revealed normal differences for both inter- and intraoperator agreement. For all volumes, similarity of the segmentations was excellent. Outliers were explained by presence of intraluminal ECAA thrombus, which hampered identification of the aneurysm outer wall. These results implicate robustness of our protocol, which is designed as a step-up towards (semi)automatic volumetric measurements to monitor patients with ECAA. Future (semi)automatic volumetric assessments are recommended and such techniques can be developed and validated using the proposed protocol and manual reference segmentations.

Extensibility and Distensibility of the Thoracic Aorta in Patients with Aneurysm.

OBJECTIVES: Reference values of aortic deformation during the cardiac cycle can be valuable for the pre-operative planning of thoracic endovascular aortic repair (TEVAR) and for facilitating computational fluid dynamics. This study aimed to quantify normal aortic extensibility (longitudinal extension) and distensibility (radial expansion), as well as pulsatile strain, in a group of 10 (>60 years) individuals with abdominal or thoracic aortic aneurysms. METHODS: ECG gated CT images of the thoracic aorta were reconstructed into virtual 3D models of aortic geometry. The centre lumen line length of the thoracic aorta and three longitudinal segments, and the aortic diameter and luminal areas of four radial intersections were extracted with a dedicated software script to calculate extensibility, longitudinal strain, distensibility, and circumferential area strain. RESULTS: Mean extensibility and longitudinal strain of the entire thoracic aorta were 3.5 [1.3-6.8] × 10-3 N-1, and 2.7 [1.0-4.5]%, respectively. Extensibility and longitudinal strain were most pronounced in the ascending aorta (20.6 [5.7-36.2] × 10-3 N-1 and 15.9 [6.6-31.9]%) and smallest in the descending aorta (4.4 [1.6-12.3] × 10-3 N-1 and 2.2 [0.7-4.7]%). Mean distensibility and circumferential area strain were most pronounced at the sinotubular junction (1.7 [0.5-2.9] × 10-3 mmHg-1 and 11.3 [3.3-18.5]%, respectively). Distensibility varied between 0.9 [0.3-2.5] × 10-3 mmHg-1 and 1.2 [0.3-3.3] × 10-3 mmHg-1 at the intersections in the aortic arch and descending aorta. CONCLUSIONS: Pulsatile deformations in both longitudinal and circumferential directions are considerable throughout the thoracic aorta. These findings may have implications for pre-operative TEVAR planning and highlight the need for devices that can mimic the significant aortic longitudinal and circumferential strains.

(18)F-FDG PET scanning of abdominal aortic aneurysms and correlation with molecular characteristics: a systematic review.

PURPOSE: The purpose of this study is to give an overview of studies investigating the role of fludeoxyglucose F18 ((18)F-FDG) positron emission tomography (PET) scanning in patients with aortic aneurysms with a focus on molecular characteristics of the aneurysm wall. METHODS: MEDLINE, EMBASE, and the Cochrane database were searched for relevant articles. After inclusion and exclusion, we selected 18 relevant articles reporting on (18)F-FDG PET scanning of aortic aneurysms. RESULTS: The sample size of studies is limited, and there are no standardized imaging protocols and quantification methods. (18)F-FDG PET scanning was shown to display molecular characteristics of the aortic wall. Different studies showed contradictory findings of aortic (18)F-FDG uptake in aneurysm patients compared to controls. CONCLUSIONS: Non-invasively determining molecular characteristics of aortic wall weakening might lead to better rupture and growth prediction. This might influence the decision of the surgeon between conservative and surgical treatment of aneurysms. To date, there is conflicted evidence regarding the use of (18)F-FDG PET scanning to predict aneurysm rupture and growth. The role of (18)F-FDG PET scanning in rupture risk prediction needs to be further investigated, and standardized imaging protocols and quantification methods need to be implemented.

Magnetic Resonance Imaging with a Weak Albumin Binding Contrast Agent can Reveal Additional Endoleaks in Patients with an Enlarging Aneurysm after EVAR.

OBJECTIVES/BACKGROUND: To examine the additional diagnostic value of magnetic resonance imaging (MRI) after administration of a weak albumin binding contrast agent in post-endovascular aneurysm repair (EVAR) patients with aneurysm growth with no or uncertain endoleak after computed tomography angiography (CTA). METHODS: This was a prospective diagnostic cross sectional study carried out between April 2011 and August 2013. MRI was performed in all patients with aneurysm growth≥5 mm after EVAR implantation and no or uncertain endoleak on CTA, or the inability, on CTA, to identify the source of a visible endoleak. All MRI scans were performed on a 1.5 T clinical MRI scanner after administration of a weak albumin binding contrast agent. The presence of endoleaks was assessed by visually comparing pre- and post-contrast T1-weighted images with fat suppression. Post-contrast images were acquired 5 and 15 minutes after contrast administration. RESULTS: Twenty-nine patients (26 men; 90%) with a median age of 74 years (interquartile range [IQR] 67-76) were included. The median interval between EVAR and MRI was 39 months (IQR 20-50). The median increase in maximum aneurysm diameter during total follow up after EVAR was 11 mm (IQR 6-17). At CTA, 16 patients (55%) had no detectable endoleak, five patients (17%) had suspected but uncertain endoleak, and eight patients had a definite endoleak (28%). On the post-contrast MRI images, endoleak was observed in 24 patients (83%). In all patients with uncertain endoleak on CTA, endoleak was detected with MRI. For type II endoleaks, feeding vessels were detected in 22/23 patients (96%) and these were all, except one, lumbar arteries. CONCLUSION: In patients with enlarging aneurysms of unknown origin after EVAR, MRI with a weak albumin binding contrast agent has additional value for both the detection and determination of the origin of the endoleak.

Catheter-directed thrombolysis for acute upper extremity ischemia.

AIM: Acute nontraumatic upper extremity ischemia has significant chronic disability when not treated adequately and timely. As surgical treatment can be challenging, this study evaluates catheter-directed thrombolysis as first-line treatment for acute upper extremity ischemia. METHODS: Between January 2006 and December 2010, 28 patients (22 women; mean age, 63±16 years) underwent catheter-directed thrombolysis for acute upper extremity ischemia, Rutherford class I or IIa. Proximal extent of the occlusion was in the subclavian (32%), axillary (7%), brachial (25%) and forearm arteries (36%). Median occlusion length was 18 cm (range, 12-43). Causes were embolus (14%), thrombus (39%), thoracic outlet syndrome (14%), paraneoplastic (4%), or unknown (29%). RESULTS: Technical success was 96%, radiologic success (>95% clot lysis) 61%, and clinical success 68%. Median duration of thrombolysis was 24 hours (range, 18-96). Of the 11 radiologically unsuccessful patients (39%), five were treated conservatively and six underwent surgical intervention. In-hospital amputation-rate was 7%. Four complications occurred: embolization to the lower extremity, a transient ischemic attack, a subcapsular splenic hematoma and a pseudoaneurysm. Cumulative amputation-free survival at six months was 93%, standard error (SE) 4.87 and at one year 88%, SE 6.50. CONCLUSION: These results show that catheter-directed thrombolysis is effective in over 60% of patients as first-line treatment of extensive acute upper extremity ischemia and can prevent surgical intervention in these patients.

Mid-Term Results of EVAR in Severe Proximal Aneurysm Neck Angulation.

OBJECTIVE: To determine if mid-term outcome following endovascular aneurysm repair (EVAR) with the Endurant Stent Graft (Medtronic, Santa Rosa, CA, USA) is influenced by severe proximal neck angulation. METHODS: A retrospective case-control study was performed using data from a prospective multicenter database. All measurements were obtained using dedicated reconstruction software and center-lumen line reconstruction. Patients with neck length >15 mm, infrarenal angle ß > 75°, and/or suprarenal angle α > 60°, or neck length >10 mm with ß > 60°, and/or α > 45° were compared with a matched control group. Primary endpoint was primary clinical success. Secondary endpoints were freedom from rupture, type 1A endoleak, stent fractures, freedom from neck-related reinterventions, and aneurysm-related adverse events. Morphological neck variation over time was also assessed. RESULTS: Forty-five patients were included in the study group and were compared with a matched control group with 65 patients. Median follow-up time was 49.5 months (range 30.5-58.4). The 4-year primary clinical success estimates were 83% and 80% for the angulated and nonangulated groups (p = .42). Proximal neck angulation did not affect primary clinical success in a multivariate model (hazard ratio 1.56, 95% confidence interval 0.55-4.41).Groups did not differ significantly in regard to freedom from rupture (p =.79), freedom from type 1A endoleak (p = .79), freedom from neck-related adverse events (p = .68), and neck-related reinterventions (p = .68). Neck angle reduction was more pronounced in patients with severe proximal neck angulation (mean deltaα -15.6°, mean deltaß -30.6°) than in the control group (mean deltaα -0.39°, mean deltaß -5.9°) (p < .001). CONCLUSION: Mid-term outcomes following EVAR with the Endurant Stent Graft were not influenced by severe proximal neck angulation in our population. Despite the conformability of the device, moderate aortic neck remodeling was identified in the group of patients with angulated neck anatomy on the first computed tomography scan after implantation with no important further remodeling afterwards. No device integrity failures were encountered.

Spontaneous delayed sealing in selected patients with a primary type-Ia endoleak after endovascular aneurysm repair.

OBJECTIVE: Direct additional therapy is advised for type-Ia endoleaks detected on completion angiography after endovascular aneurysm repair (EVAR). Additional intraoperative endovascular procedures are, however, often challenging or not possible, and direct open conversion is unattractive. The results of a selective, conservative strategy for patients with primary type-Ia endoleak has been analysed. METHODS: This was a retrospective, single-centre study (UMC, Utrecht, NL). From 2004 to 2008, all patients with a primary type-Ia endoleak and suitable anatomy for EVAR, stentgraft oversizing ≥15%, and optimal deployment were included. Complications during follow-up were studied and all sequential CTA scans were reviewed. These were compared with the remaining patients, treated during the same period. RESULTS: Fifteen patients were included (14 male, median age 77, range 67-85) with a median aneurysm diameter of 60 mm (48-80), an aneurysm neck diameter of 26 mm (21-32), a neck length of 29 mm (11-39), and infrarenal angulation of 49° (31-90). One patient suffered rupture 2 days after EVAR - leading to the only AAA-related death. Eight of the 15 type-Ia endoleaks disappeared spontaneously on the first postoperative CTA, obtained within 1 week of EVAR. On the second postoperative CTA, obtained a median of 5 months (1-12) after EVAR, all remaining endoleaks had sealed. One recurrence occurred at 4.85 years. During a median follow-up of 3.3 years, there were five secondary interventions. Compared with controls, there were more secondary (or recurrent) type-1a endoleaks (13% vs. 4%), endograft migrations (13% vs. 3%), sac growths (33% vs. 16%), and secondary interventions (33% vs. 23%). None of these differences however, were statistically significant. CONCLUSIONS: All but one of the primary type-Ia endoleaks sealed spontaneously. Until sealing, the risk of rupture persisted, but subsequently only one recurrence of type-Ia endoleak was seen. In selected patients, a conservative approach for primary type-Ia endoleaks may be justified.

Magnetic resonance imaging is more sensitive than computed tomography angiography for the detection of endoleaks after endovascular abdominal aortic aneurysm repair: a systematic review.

OBJECTIVES: The purpose of this systematic review was to examine whether magnetic resonance imaging (MRI) or computed tomography angiography (CTA) is more sensitive for the detection of endoleaks in patients with abdominal aortic aneurysm (AAA) after EVAR. DESIGN: Systematic review. MATERIALS AND METHODS: A systematic electronic search was performed. Articles were included when post-EVAR patients were evaluated by both MRI as index test and CTA as comparison. Methodological quality was assessed with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Primary outcome was the proportion of patients in whom MRI detected additional endoleaks, which were not seen with CTA. RESULTS: Eleven articles were included. The overall methodological quality of the articles was good. In total, 369 patients with 562 MRI and 562 CTA examinations were included. A total of 146 endoleaks were detected by CTA; MRI detected all but two of these endoleaks. With MRI 132 additional endoleaks were found. CONCLUSIONS: MRI is more sensitive compared to CTA for the detection of post-EVAR endoleaks, especially for the detection of type II endoleaks. MRI should be considered in patients with continued AAA growth and negative or uncertain findings at CTA.

Surgical treatment of infected aortic grafts.

An infection of an aortic prosthesis is a severe condition with high morbidity and mortality rates. Surgical treatment of an infected aortic graft or infected aortic stent-graft focuses on treatment of the infection and maintaining or restoring perfusion of the lower limbs. Over the years various reconstruction options have been introduced, each claiming to be the most successful in securing lower limb perfusion. Consensus about the optimum treatment strategy is lacking. The frail patient population and the relative rarity of the disease limits research on this topic which is an important reason for this lack of consensus. In order to determine which of the various treatment options is the most suitable to treat aortic graft infections, this systematic review was conducted of the available literature of the last 20 years. The search strategy and data collection were based on the guidelines of the Meta-analysis Of Observational Studies in Epidemiology (MOOSE). Appropriate inclusion and exclusion criteria were defined. A total of 862 possibly relevant papers were identified. After applying the in- and exclusion, data on mortality, morbidity and complications were extracted from a total of 93 papers. This review covers the various surgical treatment options available in the treatment of infected aortic (stent) grafts. Strategies concerning graft excision are discussed as are the advantages and disadvantages of the extra-anatomic reconstruction and its counterpart, the in situ reconstruction (using antibiotic-impregnated grafts, autologous vein grafts, fresh or cryopreserved allografts, and silver impregnated grafts). Available evidence was summarized and used to construct a clinical decision flowchart. All reconstruction options seem to have their pros and cons, and all have their use in specific situations. The treatment of infected aortic grafts must therefore be tailor-made.

Surgical treatment of infected aortic grafts.

An infection of an aortic prosthesis is a severe condition with high morbidity and mortality rates. Surgical treatment of an infected aortic graft or infected aortic stent-graft focuses on treatment of the infection and maintaining or restoring perfusion of the lower limbs. Over the years various reconstruction options have been introduced, each claiming to be the most successful in securing lower limb perfusion. Consensus about the optimum treatment strategy is lacking. The frail patient population and the relative rarity of the disease limits research on this topic which is an important reason for this lack of consensus. In order to determine which of the various treatment options is the most suitable to treat aortic graft infections, this systematic review was conducted of the available literature of the last 20 years. The search strategy and data collection were based on the guidelines of the Meta-analysis Of Observational Studies in Epidemiology (MOOSE). Appropriate inclusion and exclusion criteria were defined. A total of 862 possibly relevant papers were identified. After applying the in- and exclusion, data on mortality, morbidity and complications were extracted from a total of 93 papers. This review covers the various surgical treatment options available in the treatment of infected aortic (stent) grafts. Strategies concerning graft excision are discussed as are the advantages and disadvantages of the extra-anatomic reconstruction and its counterpart, the in situ reconstruction (using antibiotic-impregnated grafts, autologous vein grafts, fresh or cryopreserved allografts, and silver impregnated grafts). Available evidence was summarized and used to construct a clinical decision flowchart. All reconstruction options seem to have their pros and cons, and all have their use in specific situations. The treatment of infected aortic grafts must therefore be tailor-made.

Clinical outcome of intra-arterial embolization for treatment of patients with pelvic trauma.

Purpose. To analyse the technical success of pelvic embolization in our institution and to assess periprocedural hemodynamic status and morbidity/mortality of all pelvic trauma patients who underwent pelvic embolization. Methods. A retrospective analysis of patients with a pelvic fracture due to trauma who underwent arterial embolization was performed. Clinical data, pelvic radiographs, contrast-enhanced CT-scans, and angiographic findings were reviewed. Subsequently, the technical success and peri-procedural hemodynamic status were evaluated and described. Results. 19 trauma patients with fractures of the pelvis underwent arterial embolization. Initially, 10/19 patients (53%) were hemodynamically unstable prior to embolization. Technical success of embolization was 100%. 14/19 patients (74%) were stable after embolization, and treatment success was high as 74%. Conclusion. Angiography with subsequent embolization should be performed in patients with a pelvic fracture due to trauma and hemodynamic instability, after surgical intervention or with a persistent arterial blush indicative of an active bleeding on CT.

Final results of the prospective European trial of the Endurant stent graft for endovascular abdominal aortic aneurysm repair.

OBJECTIVES: The Endurant Stent Graft System (Medtronic Vascular, Santa Rosa, CA) is specifically designed to treat patients with abdominal aortic aneurysm, including those with difficult anatomies. This is the 1-year report of a prospective, non-randomised, open-label trial at 10 European centres. METHODS: Between November 2007 and August 2008, 80 patients were enrolled for elective endovascular aneurysm repair (EVAR) with the Endurant; 71 with moderate (≤ 60°) and nine with high (60-75°) infrarenal aortic neck angulation. Safety and stent-graft performance were assessed throughout a 1-year follow-up period. RESULTS: The device was successfully delivered and deployed in all cases. All-cause mortality was 5% (4/80), with one possibly device-related death. Serious adverse events were comparable between the high and moderate angulation groups. There were no device migrations, stent fractures, aortic ruptures or conversions to open repair. Maximal aneurysm diameter decreased >5 mm in 42.7% of cases. A total of 28 endoleaks were observed (26 type II, two undetermined). Three secondary endovascular procedures were performed for outflow vessel stenosis, graft limb occlusion and iliac extension, resulting in a secondary patency rate of 100%. No re-interventions were required in the high angulation group. CONCLUSIONS: The Endurant Stent Graft was successfully delivered and deployed in all cases and performed safely and effectively in all patients, including those with unfavourable proximal neck anatomy.

Quantitative analysis of the anterolateral ossification mass in diffuse idiopathic skeletal hyperostosis of the thoracic spine.

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic condition leading to ossification of spinal ligaments and has been shown to behave similarly to ankylosing spondylitis (AS) often leading to unstable hyperextension fractures. Currently, no quantitative data are available on the spatial relationship between the bridging anterolateral ossification mass (ALOM) and the vertebral body/intervertebral disc to explain the propensity in DISH to fracture through the vertebral body instead of through the intervertebral disc as more often seen in AS. Furthermore, no reasonable explanation is available for the typical flowing wax morphology observed in DISH. In the current study, a quantitative analysis of computed tomography (CT) data from human cadaveric specimens with DISH was performed to better understand the newly formed osseous structures and fracture biomechanics. Additionally, the results were verified using computed tomography angiography data from ten patients with DISH and ten controls. Transverse CT images were analyzed to obtain ALOM area and centroid angle relative to the anteroposterior axis; intervertebral disc and adjacent cranial and caudal levels. The ALOM area at the mid-vertebral body level averaged 57.9 ± 50.0 mm(2); at the mid-intervertebral disc space level it averaged 246.4 ± 95.9 mm(2). The mean ALOM area at the adjacent level caudal to the mid-vertebral body level was 169.6 ± 81.3 mm(2); at the adjacent cranial level, it was 161.7 ± 78.2 mm(2). The main finding was the significant difference between mean ALOM area at the mid-vertebral body level and other three levels (p < 0.0001). The subsequent verification study showed the presence of vertebral segmental arteries at the mid-vertebral body level in nearly all images irrespective of the presence of DISH. A larger area of ALOM seemed associated with increased counter-clockwise rotation (away from the aorta) of the centroid relative to the anteroposterior axis. The results from the present study suggest a predisposition for fractures through the vertebral body and a role for the arterial system in the inhibition of soft tissue ossification.

Severe proximal aneurysm neck angulation: early results using the Endurant stentgraft system.

OBJECTIVE: Angulation of the proximal aneurysm neck has been associated with adverse outcome after EVAR. We aim to investigate the influence of angulation on early results when using the Endurant Stentgraft System. METHODS: A retrospective analysis of a prospective multicentre database identified 45 elective patients treated with the Endurant stentgraft with severe angulation of the proximal neck, which were compared to a control group without significant angulation. Endpoints were early technical and clinical success, deployment accuracy and differences in operative details. RESULTS: Mean age was 74 with 86.4% males. Mean infrarenal angle (ß) was 80.8° ± 16 and mean suprarenal angle (α) was 51.4° ± 21. Patients in the angulated group had larger aneurysms (mean 309 cc vs. 187 cc), shorter necks (mean 27 mm ± 14 vs. 32.6 mm ± 13) and 74% (vs. 56%) were ASA III/IV. Technical success was 100%, with one patient requiring an unplanned proximal extension. No differences were found regarding early type-I endoleaks (0% vs. 0%), major postoperative complications (6.7% vs. 6.2%; p = 0.77) or early survival (97.8% vs. 96.9%, p = 0.79). Distance from lowest renal artery to prosthesis was 2.4 mm ± 2.7 vs. 2.3 mm ± 4.8, p = 0.9. Operative details were equivalent for both groups. CONCLUSIONS: Treatment with the Endurant stentgraft is technically feasible and safe, with satisfactory results in angulated and non-angulated anatomies alike. No sealing length was lost in extremely angulated cases, confirming the device's high conformability. Mid- and long-term data are awaited to verify durability, but early results are promising and challenge current opinion concerning neck angulation.