Intravascular Ultrasound and Peripheral Endovascular Interventions

In recent years the interest in minimal invasive surgery has been growing and the same trend can be observed in vascular surgery, leading to what is commonly referred to as lIendovascular surgery". Although the 1990s represent an era of technical revolution in vascular surgery, it is a misunderstanding to consider endovascular treatment a recent development. In 1947 J050 Cid dos Santos described the thrombo-endarterectomy'; this technique was modified by Vollmar in 1964, to a semi-closed endarterectomy using ringstrippers'> In the same year other pioneers, including Dotter and Judkins, published prelinlinary results on what they called "angioplasty" of the femoropopliteal artery using coaxial eatheters.3 This technique was later modified by Griintzig in 1974, who replaced the coaxial catheters with dilatation balloons.' In the early 1990s, Volodos and Parodi introduced the endovascular treatment of the abdominal aortic aneurysm with a device composed of a Dacron graft and Palmaz stents.5 ,6 The collaboration between interventional radiologists and vascular surgeons has been of eminent importance for further evolution of endovascular teclmiques. Nowadays a great variety of obstmctive and aneurysmal peripheral vascular diseases can be treated with catheter-guided, endovascular and, therefore, less invasive techniques. The development of these endovascular techniques prompted the need for improved vascular imaging and better diagnostics. Since angiography displays only a "lumenogram II of the vessel, tills prechldes qualitative evaluation of atherosclerotic plaque and quantitative assessment of plaque and vessel. Sophisticated modalities such as colour duplex, computed tomographic angiography and magnetic resonance imaging can be important in the pre- and postintervention assessment of vascular disease. These techniques, however, do not always give accurate information on the dimensions of the vessel or the extent of the disease and at the present time cannot be used during intervention.7 Intravascular ultrasound depicts both the vascular lumen and vascular wall: thus, inform

Familial predisposition of thoracic outlet syndrome:does a familial syndrome exist? Report of cases and review of literature

Introduction: Neurogenic thoracic outlet syndrome (NTOS) is caused by compression of the brachial plexus. The clinical presentation of NTOS is characterized by symptoms of pain, paresthesia, numbness or muscle weakness in the neck, arm or hand. Methods: In this case report, five patients were diagnosed with NTOS. They all had a first degree relative with NTOS as well. Conlusions: These cases show familial predisposition in thoracic outlet syndrome. Could a form of familial TOS exist?

Intravascular ultrasonography allows accurate assessment of abdominal aortic aneurysm: An in vitro validation study

AbstractObjective: The objective of this study was to acquire insight into the interpretation of intravascular ultrasound images of the abdominal aorta and to assess to what extent this technique can provide useful parameters for the endovascular treatment of patients with abdominal aortic aneurysm. Study Design: This was a descriptive study. Methods: Fifteen abdominal aortic specimens (normal, atherosclerotic, or aneurysmal) were studied. Ultrasonic images and corresponding histologic sections were compared for vessel wall characteristics, lesion morphologic characteristics, and lumen diameter. The length of the aneurysm and the length of the proximal and distal neck were measured and compared with external measurements. Tomographic images were reconstructed to a three-dimensional format. Results: Normal aortic wall was seen as a two- or three-layered structure corresponding with intima, media, and adventitia. A distinction could be made among fibrous lesion, calcified lesion, and thrombus and between normal and aneurysmal aorta. Correlation between the histologic specimens and intravascular ultrasonography for lumen diameter measurements was high (r = 0.93; p < 0.001). In a similar fashion, correlation between external measurements and intravascular ultrasound measurements on the length of the aneurysm and its proximal and distal neck was high (r = 0.99; p < 0.001). Three-dimensional analysis enhanced interpretation of the tomographic images by visualizing the spatial position of anatomic structures and contributed to understanding the shape and dimensions of the aneurysm. Conclusions: Intravascular ultrasonography provides accurate information on the vessel wall, lesion morphologic characteristics, and quantitative parameters of the abdominal aorta. Spatial information supplied by three-dimensional analysis contributes to a more realistic interpretation of the tomographic images. (J Vasc Surg 1998;27:347-53.

3D-Ultrasound Based Mechanical and Geometrical Analysis of Abdominal Aortic Aneurysms and Relationship to Growth

The heterogeneity of progression of abdominal aortic aneurysms (AAAs) is not well understood. This study investigates which geometrical and mechanical factors, determined using time-resolved 3D ultrasound (3D + t US), correlate with increased growth of the aneurysm. The AAA diameter, volume, wall curvature, distensibility, and compliance in the maximal diameter region were determined automatically from 3D + t echograms of 167 patients. Due to limitations in the field-of-view and visibility of aortic pulsation, measurements of the volume, compliance of a 60 mm long region and the distensibility were possible for 78, 67, and 122 patients, respectively. Validation of the geometrical parameters with CT showed high similarity, with a median similarity index of 0.92 and root-mean-square error (RMSE) of diameters of 3.5 mm. Investigation of Spearman correlation between parameters showed that the elasticity of the aneurysms decreases slightly with diameter (p = 0.034) and decreases significantly with mean arterial pressure (p &lt; 0.0001). The growth of a AAA is significantly related to its diameter, volume, compliance, and surface curvature (p &lt; 0.002). Investigation of a linear growth model showed that compliance is the best predictor for upcoming AAA growth (RMSE 1.70 mm/year). To conclude, mechanical and geometrical parameters of the maximally dilated region of AAAs can automatically and accurately be determined from 3D + t echograms. With this, a prediction can be made about the upcoming AAA growth. This is a step towards more patient-specific characterization of AAAs, leading to better predictability of the progression of the disease and, eventually, improved clinical decision making about the treatment of AAAs

The year in cardiology 2014: peripheral circulation

In 2014, the debate on the indication of revascularization in case of asymptomatic carotid disease continued, while another one regarding the use of surgery vs. stenting addressed some new issues regarding the long-term cardiac risk of these patients. Renal arteries interventions trials were disappointing, as neither renal denervation nor renal artery stenting was found associated with better blood pressure management or outcome. In contrast, in lower-extremities artery disease, the endovascular techniques represent in 2014 major alternatives to surgery, even in distal arteries, with new insights regarding the interest of drug-eluting balloons. Regarding the aorta, the ESC published its first guidelines document on the entire vessel, emphasizing on the role of every cardiologist for screening abdominal aorta aneurysm during echocardiography. Among vascular wall biomarkers, the aorta stiffness is of increasing interest with new data and meta-analysis confirming its ability to stratify risk, whereas carotid intima-media thickness showed poor performances in terms of reclassifying patients into risk categories beyond risk scores. Regarding the veins, new data suggest the interest of D-dimers and residual venous thrombosis to help the decision of anti-coagulation prolongation or discontinuation after the initial period of treatment for deep vein thrombosi

Enabling strain imaging in realistic Eulerian ultrasound simulation methods

Cardiovascular strain imaging is continually improving due to ongoing advances in ultrasound acquisition and data processing techniques. The phantoms used for validation of new methods are often burdensome to make and lack flexibility to vary mechanical and acoustic properties. Simulations of US imaging provide an alternative with the required flexibility and ground truth strain data. However, the current Lagrangian US strain imaging models cannot simulate heterogeneous speed of sound distributions and higher-order scattering, which limits the realism of the simulations. More realistic Eulerian modelling techniques exist but have so far not been used for strain imaging. In this research, a novel sampling scheme was developed based on a band-limited interpolation of the medium, which enables accurate strain simulation in Eulerian methods. The scheme was validated in k-Wave using various numerical phantoms and by a comparison with Field II. The method allows for simulations with a large range in strain values and was accurate with errors smaller than −60 dB. Furthermore, an excellent agreement with the Fourier theory of US scattering was found. The ability to perform simulations with heterogeneous speed of sound distributions was demonstrated using a pulsating artery model. The developed sampling scheme contributes to more realistic strain imaging simulations, in which the effect of heterogenous acoustic properties can be taken into account

Endovascular repair versus open surgery in patients with ruptured abdominal aortic aneurysms: Clinical outcomes with 1-year follow-up

ObjectiveTo compare the clinical outcomes of treatment after endovascular repair and open surgery in patients with ruptured infrarenal abdominal aortic aneurysms (AAAs), including 1-year follow-up.MethodsAll consecutive conscious patients with ruptured infrarenal AAAs who presented to our tertiary care teaching hospital between January 1, 2001, and December 31, 2005, were included in this study (n = 55). Twenty-six patients underwent endovascular repair, and 29 patients underwent open surgery. Patients who were hemodynamically too unstable to undergo a computed tomography angiography scan were excluded. Outcomes evaluated were intraoperative mortality, 30-day mortality, systemic complications, complications necessitating surgical intervention, and mortality and complications during 1-year follow-up. The statistical tests we used were the Student t test, χ2 test, Fisher exact test, and Mann-Whitney U test (two sided; α = .05).ResultsThirty-day mortality was 8 (31%) of 26 patients who underwent endovascular repair and 9 (31%) of 29 patients who underwent open surgery (P = .98). Systemic complications and complications necessitating surgical intervention during the initial hospital stay were similar in both treatment groups (8/26 [31%] and 5/26 [19%] for endovascular repair, respectively, and 9/29 [31%] and 8/29 [28%] for open surgery, respectively; P > .40). During 1-year follow-up, two patients initially treated with endovascular repair died as a result of non–aneurysm-related causes; no death occurred in the open surgery group. Complications during 1-year follow-up were 1 (5%) of 20 for endovascular repair and 4 (16%) of 25 for open surgery (P = .36).ConclusionsOn the basis of our study with a highly selected population, the mortality and complication rates after endovascular repair may be similar compared with those after open surgery in patients treated for ruptured infrarenal AAAs

Evaluation of a dedicated dual phased-array surface coil using a black-blood FSE sequence for high resolution MRI of the carotid vessel wall

Purpose: To investigate the ability of magnetic resonance imaging (MRI) to visualize the carotid vessel wall using a phased-array coil and a black-blood (BB) fast spin-echo (FSE) sequence. Materials and Methods: The phased-array coil was compared with a three-inch coil. Images from volunteers were evaluated for artifacts, wall layers, and wall signal intensity. Signal intensity and homogeneity of atherosclerosis were assessed. Lumen diameter and vessel area were measured. Results: Comparison between the phased-array coil and the three-inch coil showed a 100% increase in signal-to-noise ratio. BB-FSE imaging resulted in good delineation between blood and vessel wall. Most volunteers had a two-layered vessel wall with a hyperintense inner layer. MRI showed both homogeneous hyperintense and heterogeneous plaques, which consisted of a main hyperintense part with hypointense spots and/or intermediate regions. MRI lumen and area measurements were performed easily. Conclusion: High resolution MRI of carotid atherosclerosis is feasible with a phased-array coil and a BB-FSE sequence

Accurate assessment of abdominal aortic aneurysm with intravascular ultrasound scanning: Validation with computed tomographic angiography

AbstractPurpose: The purpose of this study was to assess the accuracy of intravascular ultrasound (IVUS) parameters of abdominal aortic aneurysm, used for endovascular grafting, in comparison with computed tomographic angiography (CTA). Methods: This study was designed as a descriptive study. Between March 1997 and March 1998, 16 patients with abdominal aortic aneurysms were studied with angiography, IVUS (12.5 MHz), and CTA. The length of the aneurysm and the length and lumen diameter of the proximal and distal neck obtained with IVUS were compared with the data obtained with CTA. The measurements with IVUS were repeated by a second observer to assess the reproducibility. Tomographic IVUS images were reconstructed into a longitudinal format. Results: IVUS results identified 31 of 32 renal arteries and four of five accessory renal arteries. A comparison of the length measurements of the aneurysm and the proximal and distal neck obtained with IVUS and CTA revealed a correlation of 0.99 (P < .001), with a coefficient of variation of 9%. IVUS results tended to underestimate the length as compared with the CTA results (0.48 ± 0.52 cm; P < .001). A comparison of the lumen diameter measurements of the proximal and distal neck derived from IVUS and CTA showed a correlation of 0.93 (P < .001), with a coefficient of variation of 9%. IVUS results tended to underestimate aneurysm neck diameter as compared with CTA results (0.68 ± 1.76 mm; P = .006). Interobserver agreement of IVUS length and diameter measurements showed a good correlation (r = 1.0; P < .001), with coefficients of variation of 3% and 2%, respectively, and no significant differences (0.0 ± 0.16 cm and 0.06 ± 0.36 mm, respectively). The longitudinal IVUS images displayed the important vascular structures and improved the spatial insight in aneurysmal anatomy. Conclusion: Intravascular ultrasound scanning results provided accurate and reproducible measurements of abdominal aortic aneurysm. The longitudinal reconstruction of IVUS images provided additional knowledge on the anatomy of the aneurysm and its proximal and distal neck. (J Vasc Surg 1999;29:631-8.

Geometric Analysis of the Gore Excluder Conformable Endoprosthesis in the Infrarenal Aortic Neck: One Year Results of the EXCeL Registry

Objective: The Gore Excluder Conformable Endoprosthesis (CEXC) is designed to treat challenging infrarenal anatomy because of its active angulation control, repositionability, and enhanced conformability. This study evaluated 30 day and one year position and apposition of the CEXC in the infrarenal neck. Methods: Patients treated with the CEXC between 2018 and 2022 with an available 30 day computed tomography angiogram (CTA) were selected from four hospitals in a prospective registry. Endograft apposition (shortest apposition length [SAL]) and position (shortest fabric distance [SFD]) were assessed on the 30 day and one year CTAs. Maximum infrarenal aortic curvature was compared between the pre- and post-operative CTAs to evaluate conformability of the CEXC. Results: There were 87 patients with a 30 day CTA, and for 56 of these patients the one year CTA was available. Median (interquartile range [IQR]) pre-operative neck length was 22 mm (IQR 15, 32) and infrarenal angulation was 52° (IQR 31, 72). Median SAL was 21.2 mm (IQR 14.0, 29.3) at 30 days for all included patients. The SAL in 13 patients (15%) was &lt; 10 mm at 30 days, and one patient had a SAL of 0 mm and a type Ia endoleak. There was no significant difference in SAL between patients within and outside instructions for use. The SAL significantly increased by 1.1 mm (IQR −2.3, 4.7; p =.042) at one year. The SAL decreased in seven patients (13%), increased in 13 patients (23%), and remained stable in 36 patients (64%). Median SFD was 2.0 mm (IQR 0.5, 3.6) at 30 days, which slightly increased by 0.3 mm (IQR −0.5, 1.8; p =.019) at one year. One patient showed migration (SFD increase ≥ 5 mm). Median endograft tilt was 15.8° (IQR 9.7, 21.4). Pre-operative maximum infrarenal curvature was 36 m −1 (IQR 26, 56) and did not significantly change thereafter. Conclusion: In most patients, the CEXC was implanted close to the renal arteries, and sufficient (≥ 10 mm) post-operative apposition was achieved at 30 days, which slightly increased at one year. Post-operative endograft tilt was relatively low, and aortic geometry remained unchanged after implantation of the CEXC, probably due to its high conformability.</p