Tuberculous Aneurysm of the Abdominal Aorta: Endovascular Repair Using Stent Grafts in Two Cases

Tuberculous aneurysm of the aorta is exceedingly rare. To date, the standard therapy for mycotic aneurysm of the abdominal aorta has been surgery involving in-situ graft placement or extra-anatomic bypass surgery followed by effective anti-tuberculous medication. Only recently has the use of a stent graft in the treatment of tuberculous aortic aneurysm been described in the literature. We report two cases in which a tuberculous aneurysm of the abdominal aorta was successfully repaired using endovascular stent grafts. One case involved is a 42-year-old woman with a large suprarenal abdominal aortic aneurysm and a right psoas abscess, and the other, a 41-year-old man in whom an abdominal aortic aneurysm ruptured during surgical drainage of a psoas abscess.     

Intraluminal calcification and occlusion of the abdominal aorta above the renal arteries

In a 38-year-old man, severe hypertension was caused by a calcified thrombotic occlusion of the abdominal aorta above the renal arteries. Dense calcification in the abdominal aorta was demonstrated on plain radiographs and computed tomography. The location of the occlusion was confirmed by angiography. The possible causes included aortitis, trauma, rubella syndrome, and atherosclerosis.     

Angiography and magnetic resonance imaging of aortic dissection

This review article describes and illustrates the role of angiography and magnetic resonance imaging in the evaluation of aortic dissection. Clinical findings, complications, classification, and treatment of dissection are reviewed as well.     

Fatal abdominal aortic compression associated with thoracic vertebral fracture-dislocation after a short fall

Abdominal aortic injury after blunt trauma is a rare event, as these injuries occur much less frequently than do those of the thoracic aorta. We present an unusual case of fatal abdominal aortic compression with presumed compression associated with a fracture-dislocation of the T11 vertebral body after a short fall, which to our knowledge is the first reported case of this type.     

Mycotic aneurysm of the aorta: MRI and MRA features

Mycotic aneurysms of the abdominal aorta are potentially fatal but uncommon. We report the MRI and MRA features of an abdominal aortic mycotic aneurysm in a patient who presented with nonspecific low back pain. By delineating the saccular nature of the aneurysm and identifying the coexistence of vertebral enhancement, MRI was crucial for the final diagnosis. A potential pitfall of contrast-enhanced MRA is also demonstrated.     

Right cervical aortic arch with subaortic left brachiocephalic vein: MRI findings

A case of a right cervical aortic arch associated with a subaortic left brachiocephalic vein is reported. CT and MRI findings were correlated to the angiogram. The mechanism responsible for the coexistence of these two abnormalities is discussed. Correspondence to: C. Beigelman     

Immediate postgadolinium spoiled gradient-echo MRI for evaluating the abdominal aorta in the setting of abdominal MR examination

To assess the reproducibility and image quality of immediate postgadolinium chelate spoiled gradient-echo MRI in demonstrating disease of the abdominal aorta. All patients (27 patients: 21 men, 6 women) with substantial disease of the abdominal aorta, who underwent abdominal MR examinations at 1.5 T between 1991 and 1995, were entered in the study. Patients were referred for evaluation of suspected aortic disease (14 patients) or other abdominal diseases (13 patients). Three experienced investigators manually measured luminal and external aortic wall diameters and rated image quality, definition of inner and outer walls, extent of disease, and presence of other abdominal abnormalities, in an independent fashion. A cardiovascular surgeon then rated all studies to determine whether clinical management could be based on the MR findings alone. There was 98 to 99% agreement in measurements of luminal and external wall diameter between the three investigators. Overall image quality was rated as good in 77.8 to 88.9% of patients. A total of 31 additional nonaortic abdominal abnormalities were detected by all observers. The cardiovascular surgeon rated 25 of 27 studies as adequate to determine clinical management based on MR findings alone. Immediate postgadolinium spoiled gradient-echo MRI is a reproducible technique for the demonstration of abdominal aortic disease and possesses good image quality. Advantages of this technique include simultaneous evaluation of other nonvascular diseases of the abdomen, short examination time, and easy implementation as part of routine abdominal MRI scanning protocol.     

Double aortic arch: An orifice projection using angled cineangiography

Double aortic arches are usually shown angiographically by an injection of contrast in the aortic root with filming in the frontal (PA) and lateral projections. This is not completely satisfactory, however, as superimposition may mask the site of an associated atresia, which dictates the point at which the narrower arch should be divided. An angled view of the orifice of the ring, obtained in a six-week-old boy, showed the complete anatomy of the malformation.     

Measurement of collateral blood flow in a porcine model of aortic coarctation by velocity-encoded cine MRI

The purpose of this study was to investigate the time course of development of collateral blood flow in an animal model of aortic coarctation. A juxtaductal aortic stenosis (model coarctation) was surgically created in five juvenile pigs. MRI was performed preoperatively, 1 to 2 days postoperatively, and 2 to 10 weeks postoperatively. Aortic blood flow was measured by velocity-encoded cine MR (VENC-MR). The percent change in aortic blood flow (ΔBF) from proximal to distal descending thoracic aorta was calculated, and a multiple-comparison paired t test used to assess changes in ΔBF over time. Invasive flow measurements were obtained in one animal before sacrifice using an ultrasonic probe. ΔBF preoperatively was ?2 ± 8% (mean ± SE). ΔBF increased to 32 ± 7% (mean ± SE, P = .022) 2 days postoperatively and 55 ± 19% (P = .032) 2 to 8 weeks postoperatively. Invasive measurements were in qualitative agreement with the VENC-MR data. VENC-MR is an accurate noninvasive method of measuring collateral blood flow in aortic coarctation. Recruitment and development of collateral flow pathways occur rapidly in an animal model.     

Infrarenal aortic stents: Initial clinical experience and angiographic follow-up

From March 1990 to May 1991, arterial stents were placed in seven patients because of a tight stenosis (five patients) or a total chronic occlusion (two patients) located in the infrarenal aorta. In one case, the aortic occlusion extended to both common iliac arteries. After balloon dilatation, aortic stents were successfully positioned in all cases. Bilateral common iliac recanalization and stent placement were performed in one case. No complications occurred in any of the patients. Follow-up data were derived from clinical assessments and angiographic results. After a 15.1-month mean follow-up period (range 12–24 months), the seven aortic stents remained patent. Three iliac artery procedures were performed in two of the patients as well. Claudication recurred in three of the seven patients which was related to a common iliac occlusion (one case) or distal progression of atherosclerosis (two cases). Aortic stents seem to be suitable for treating failed angioplasty of aortic lesions but the procedure remains technically difficult when there is associated severe atherosclerosis of the proximal common iliac arteries. Nevertheless, considering the morbidity rate (0%) and the patency rate in this series, this technique could become an alternative to surgical treatment for infrarenal aortic occlusive lesions.     

Percutaneous transluminal aortic angioplasty: Early and late results

Percutaneous transluminal angioplasty of the infrarenal abdominal aorta (13 patients) and its bifurcation (15 patients) was performed in 28 patients with a total of 32 dilatation procedures. The group consisted of 16 female and 12 male patients and initial successful dilatation was achieved in all Recurrence within 1 month requiring bypass surgery occurred in 1 patient. Three patients were lost to follow-up. Long-term follow-up in the remaining 24 patients ranged from 1 to 9 years with a mean of 4.5 years. During the follow-up period, repeat angioplasty of the original stenosis was performed in 3 patients and another patient underwent dilatation of a new lesion which developed in the aorta. According to clinical and noninvasive studies, these 4 patients, as well as the other 20, have maintained patency of the treated lesions and are symptom free. No immediate complications requiring surgery occurred. We conclude that angioplasty is the initial treatment of choice in focal lesions of the distal abdominal aorta and its bifurcation.     

Flow pattern analysis in the abdominal aorta with velocity-encoded cine MR imaging

The sites of deposition of atherosclerotic plaque on the aortic wall are considered to be influenced by secondary and retrograde flow patterns that cause regions of altered shear stress. To detect secondary flow patterns and areas of retrograde flow in the abdominal aorta, velocity-encoded cine (VEC) magnetic resonance (MR) imaging was performed at five different levels of the abdominal aorta in nine healthy volunteers. Net retrograde flow (expressed as a percentage of antegrade flow) increased from proximal to distal levels and was maximal (13.8% ± 11.8) just distal to the origin of the renal arteries. An increase in the duration of retrograde flow over the cardiac cycle was observed from proximal to distal levels. Whereas retrograde flow was present at end systole and early diastole in each volunteer at every level, the duration and amount of retrograde flow during diastole showed high interindividual variation. Such differences suggest the possibility of variable vascular geometric risk factors in the population for the development of atherosclerotic plaque. The location of retrograde flow in the abdominal aorta demonstrated in vivo with VEC MR imaging was close to that obtained with in vitro flow visualization studies in models of the abdominal aorta.     

Serial aortography assesses stability of “Atypical” aortic arch ruptures

The victim of a high speed motor vehicle accident sustained an ascending aortic laceration as well as avulsion of the left subclavian artery. Initial management of the tears was conservative. The case is typical of “atypical” aortic arch tears except that the patient survived without emergent surgery. Serial aortography proved useful in assessing stability of the tears, providing opportunity to observe the natural history of these injuries angiographically. The distribution of aortic arch injuries following blunt trauma is reviewed.     

Use of through-and-through guidewire for delivering large stent-grafts into the distal aortic arch

The availability of large diameter stent-grafts is now allowing the endovascular treatment of thoracic aortic aneurysms. Most aneurysms are closely related to the distal arch and it is thus necessary to pass the delivery systems into the arch to effectively cover the proximal neck. Even with extra-stiff guidewires in position, it may still be difficult to achieve this, as a result of tortuosity at the iliac arteries and the aorta. We detail a technique where a stiff guidewire is passed from a brachial entry point through the aorta and out at the femoral arteriotomy site. This allows extra-support and may enable the delivery system to be passed further into the aortic arch than it could with just the regular guidewire position.     

Aortic dissection with “normal” chest roentgenogram

Two patients were studied who had aortic dissections and chest roentgenograms not suggestive of that diagnosis. Since a normal chest roentgenogram does not necessarily exclude this diagnosis, aortography is indicated, if aortic dissection is strongly suspected clinically.     

双源CT对主动脉壁内血肿影像诊断

目的：评价双源CT（DSCT）诊断主动脉壁内血肿的价值。方法：采用西门子DSCT扫描机,连续容积增强扫描,对25例主诉急性胸背痛患者进行DSCT检查并诊断为主动脉壁内血肿。结果：25例按Stanford分型：A型7例,B型18例。DSCT所见主动脉壁内血肿的直接征象：主动脉壁呈新月形或环形增厚≥5mm,无内膜破裂形成的主动脉征象。间接征象：钙化内移7例,穿透性溃疡征12例,主动脉壁粥样硬化改变18例,内膜渗漏5例。并发征象：心包积液5例,胸腔积液14例,主要分支血管受累5例,主动脉夹层3例,主动脉瘤4例。结论：DSCT能为主动脉壁内血肿的诊断和治疗提供重要信息,且便于治疗后随诊观察。     

不典型主动脉夹层的多层螺旋CT诊断价值

目的:回顾性分析不典型主动脉夹层(atypical aortic dissection,AAD)的CT表现,探讨螺旋CT诊断AAD的价值。方法:25例AAD患者,全部行平扫及增强扫描,并结合多平面重组、曲面重组等方法显示AAD及穿透溃疡,根据Stan-ford分类法分型。结果:25例AAD,A型7例,B型18例。主要CT表现:主动脉壁呈新月型或环形增厚,无内膜破裂形成的双腔主动脉征象,增强扫描假腔无强化。内膜钙化向内移位7例,穿透性溃疡征3例。并发心包、纵隔及胸腔积液和积血共10例。经内科保守治疗后,6例完全吸收,3例部分不典型吸收,2例无明显变化。结论:螺旋CT清楚显示夹层的部位、范围及并发症,可作为主动脉夹层的首选检查及随访方法。     

64层螺旋CT低剂量对比剂主动脉成像的可行性研究

目的：探讨64层螺旋C T主动脉血管成像中使用低剂量对比剂的可行性。方法60例主动脉血管成像患者,随机分为A、B、C三组：A组对比剂量80ml＋生理盐水20ml冲洗;B组对比剂量70ml＋生理盐水30ml冲洗;C组对比剂量60ml＋生理盐水40ml冲洗。注射速率均为5ml/s ,扫描延迟时间采用自动触发技术。原始数据均传至工作站,进行图像重组,并测量升主动脉、T7及L2水平降主动脉、主动脉分叉处CT 值。由主治医师及副主任医师各一名共同阅片,对血管强化程度、主要分支血管显示清晰度进行评价。结果 A、B、C三组血管强化程度、主要分支血管显示清晰度均无统计学差异。结论在64层螺旋CT主动脉血管成像中,应用低剂量对比剂60ml＋生理盐水40ml冲洗,图像质量满意,可以满足临床诊断要求。     

Congenital subclavian steal associated with an unusual type of right aortic arch

A case of congenital subclavian steal caused by a previously unreported aortic arch anomaly was demonstrated by angiography. The patient was shown to have a right aortic arch with a retroesophageal segment, a stenotic proximal portion of the left subclavian artery, and a left descending aorta.     

Exercise-related changes in aortic flow measured with spiral echo-planar MR velocity mapping

Spiral echo-planar magnetic resonance (MR) velocity mapping was used to measure exercise-related changes in flow in the descending thoracic aorta in 10 healthy volunteers. Flow was measured at rest and Immediately after dynamic exercise, with a 0.5-T imager with a surface receiving coil and electrocardiographic triggering. Supine exercise was performed with a home-built pedaling apparatus. Spiral velocity mapping was performed in a transverse plane through the descending thoracic aorta with the subject at rest. The subject was then asked to perform maximum exercise, stop, and hold his breath during a four-heartbeat acquisition time. Eight cine frames with a temporal resolution of 50 msec were acquired through systole. Each image was acquired in 40 msec during spiral acquisition of k-space data, starting at the center, 6 msec after the excitation pulse. Reproduclbility of the technique was established by repeating the flow measurement in four consecutive heartbeats. At rest, the heart rate (mean ± standard deviation), mean aortic flow, peak aortic flow, and time to peak flow were 68 beats per minute ± 6, 41 mllliliters per beat ±8, 107 mL/sec ± 20, and 175 msec ± 25, respectively. After exercise, the heart rate and mean and peak aortic flow were significantly increased (P < 0.001), measuring 101 beats per minute ±12, 57 milliliters per beat ± 11, and 158 mL/sec ±29, respectively, while the time to peak flow (115 msec ±32) was significantly reduced (P < 0.001). The four sets of values obtained for the first four consecutive heartbeats measured at rest were similar, as were those obtained for the first four heartbeats after exercise.