OBJECTIVES:

To assess the influence of different table feeds (TFs) on vascular enhancement and image quality in patients with an abdominal aortic aneurysm (AAA) undergoing computed tomography (CT) angiography of the lower extremities (run-off CTA).

METHODS:

Seventy-nine patients (71 ± 8 years) with an AAA (>30 mm) who underwent run-off CTA between January 2004 and August 2011 were included in this retrospective institutional review board-approved study. Run-off CTA was conducted using 16- and 64-row CT. The range of TFs was 30-86 mm/s and was categorised in quartiles TF1 (32.6 ± 1.9 mm/s), TF2 (38.9 ± 0.9 mm/s), TF3 (43.9 ± 3.1 mm/s) and TF4 (57.4 ± 10.5 mm/s). Image quality was rated independently by two radiologists and vessel enhancement was assessed.

RESULTS:

Image quality was diagnostic at all aortic, pelvic and almost all thigh levels. Below the knee, the number of diagnostic levels was highest for TF1 and decreased to TF4. Arterial enhancement between the aorta and fibular trunk was not different in all TF groups, P > 0.05. At the calf and foot strongest arterial enhancement was noted for TF1 and TF2 and decreased to TF4, P < 0.01.

CONCLUSION:

Results indicate that the highest image quality of run-off CTA in patients with an AAA may be obtained using table feeds measuring 30-35 mm/s. KEY POINTS : • CTA has become a key investigation for peripheral vascular disease. • Run-off CTA is more complex in patients with an abdominal aortic aneurysm. • Run-off CTA is feasible with a short bolus of intravenous contrast medium. • A constant 30-35 mm/s table feed provides the highest likelihood of diagnostic images.

BACKGROUND:

Examination of a large collective combined with individual case analyses may give new insights into mechanisms and prevention of spinal cord ischemia (SCI) after thoracic endovascular repair.

METHODS:

In an 11-year period, stent-grafts were implanted in 406 patients for various aortic pathologic conditions. The mean age was 63 years (15-91 years) and 300 (74%) patients were men; 58 patients underwent staged thoracic stent-graft procedures. The length of aorta covered was between 75 and 584 mm (mean, 204 mm). Thoracoabdominal branched or fenestrated stent-grafts were implanted in 11 patients. The left subclavian artery was occluded in 161 patients (39%); this occurred in half of them (n = 78) after protective revascularization. Prophylactic cerebrospinal fluid (CSF) drainage was used selectively in 4 cases; no neuromonitoring was used.

RESULTS:

The incidence of SCI was 2.7% (n = 11); 6 patients (1.5%) had major permanent deficits. Conditions that had a potential influence on SCI were analyzed. Statistical correlation was found for previous conventional or endovascular abdominal aortic aneurysm repair (odds ratio [OR], 4.8), coverage of the entire descending thoracic aorta (OR, 3.6), and implantation of thoracoabdominal branched and fenestrated stent-grafts (OR, 9.5). Individual analyses revealed other conditions that might have played a role, such as embolization into the segmental arteries, severe visceral ischemia, profound hemorrhagic shock, and heparin-induced thrombocytopenia.

CONCLUSIONS:

The incidence of SCI is unexpectedly low despite extensive sacrifice of intercostal arteries. Extended coverage of the thoracic and thoracoabdominal aorta seems to have a higher risk, but other factors may contribute to the individual disaster.

Dissection of the aorta is a rare yet potentially serious complication following endovascular abdominal aortic aneurysm (EVAR). These can lead to visceral branch hypoperfusion, compromise of aneurysm exclusion, arterial dilation or rupture. Intimal injury and dissection in the context of EVAR may be associated with a number of risk factors that include adverse infrarenal neck morphology, device oversizing, barbed fixation and wire manipulation in the proximal aorta. Herein, we describe three cases of type B aortic dissection following EVAR and discuss possible causes. As the applicability of endovascular technology widens, clinicians are reminded of the importance of early recognition and detection of unusual sequelae following EVAR.

BACKGROUND:

We evaluated the occurrence and treatment of aortic aneurysms in coarctation patients.

METHODS:

During 1962 to 2011, 943 cases of coarctation were repaired. Aortic aneurysms were identified in 55 patients (5.8%). Forty-eight had prior coarctation repair (median 23 years earlier, interquartile range 18 to 26 years). Forty-two aneurysms were found in the descending thoracic aorta (76.4%), 18 in the ascending aorta (32.7%), 8 in the left subclavian artery (14.5%), and 1 each (1.8%) in the abdominal aorta, iliac artery, and innominate artery. Twenty-three patients (41.8%) had multiple aneurysms. Twenty-five patients (45.4%) had a bicuspid aortic valve.

RESULTS:

Fifty-three patients' aneurysms were treated surgically. Thirty-five (66.0%) had descending thoracic aortic repair, of whom 11 had aorto-left subclavian bypass. Aortic cross-clamping alone was used in 23 patients, left heart bypass in 4, and circulatory arrest in 8. Eleven patients underwent endovascular repair (20.8%). Proximal aortic aneurysms were repaired in 7 patients (13.2%); 1 had simultaneous antegrade endostent delivery. Four patients had ascending-to-descending aortic bypass (7.3%). Concomitant valve-sparing root repair was performed in 2 patients, Bentall in 4, aortic valve replacement in 3, and coronary artery bypass in 1. One 30-day death occurred (1.9%). Three patients (5.7%) had transient neurologic deficits, 2 (3.8%) required tracheostomy, and 11 (20.8%) had vocal cord paralysis.

CONCLUSIONS:

Coarctation is a marker for aortic aneurysm formation in adults and merits long-term surveillance. Anatomic complexity and associated conditions can complicate the surgical repair. Various open, extra-anatomic, and endovascular techniques may be used.

: Aortic dissection(AD) is an acute process of large blood vessels characterized by dangerous pathogenic conditions and high disability and high mortality. The pathogenesis of AD remains debated. Matrix metalloproteinase-12 (MMP-12) participates in many pathological processes such as abdominal aortic aneurysm, atherosclerosis, emphysema and cancer. However, this elastase has rarely been assessed in the presence of AD. The aim of the present study was to investigate the expression of MMP-12 in aortic tissue so as to offer a better understanding of the possible mechanisms of AD.

METHODS:

The protein expression levels of MMP-12 were analyzed and compared in aorta tissue and the blood serum samples by reverse transcription polymerase chain reaction(RT-PCR), Western blotting, immuno-histochemistry, fluorescence resonance energy transfer ( FRET ) activity assay and enzyme-linked immuno sorbent assay ( ELISA ), respectively. Ascending aorta tissue specimens were obtained from 12 patients with an acute Stanford A-dissection at the time of aortic replacement, and from 4 patients with coronary artery disease (CAD) undergoing coronary artery bypass surgery. Meanwhile, serum samples were harvested from 15 patients with an acute Stanford A-dissection and 10 healthy individuals who served as the control group.

RESULTS:

MMP-12 activity could be detected in both AD and CAD groups, but the level in the AD group was higher than those in the CAD group (P < 0.05). MMP-12 proteolysis existed in both serum samples of the AD and healthy groups, and the activity level in the AD group was clearly higher than in the healthy group (P < 0.05). For AD patients, MMP-12 activity in serum was higher than in the aorta wall (P < 0.05). MMP-12 activity in the aortic wall tissue can be inhibited by MMP inhibitor v (P < 0.05).

CONCLUSION:

The present study directly demonstrates that MMP-12 proteolytic activity exists within the aorta specimens and blood samples from aortic dissection patients. MMP-12 might be of potential relevance as a clinically diagnostic tool and therapeutic target in vascular injury and repair.

Outcomes of abdominal aortic aneurysm (AAA) repair have improved in the 2 decades since the emergence of endovascular aneurysm repair (EVAR). However, EVAR is considered a contraindication for shaggy aorta because of the high risk of shower embolization. Recently, statins have been implicated in preventing embolization in patients with shaggy aorta via its pleiotropic effects, including atheroma reduction and coronary artery stabilization. We selected pitavastatin, a statin with potent effects, discovered and developed by a Japanese company because it has shown excellent pleiotropic effects on atheromatous arteries in the Japanese population. A randomized comparison study of dose-dependent effects of pitavastatin in patients with AAA with massive atheromatous aortic thrombus (PROCEDURE study) has begun. PROCEDURE has an enrollment goal of up to 80 patients with AAA with massive aortic atheroma (excluding intrasac atheroma), randomly allocated into 2 groups receiving pitavastatin at a dose of 1 or 4 mg/day. The endpoints of the PROCEDURE study include change in atheroma volume, major adverse events related to shower embolization after aneurysm repair, and lipid-lowering effects. When complete, results of the PROCEDURE study should provide objective evidence to use statins preoperatively for AAA with massive aortic atheroma.

Aortoenteric fistula (AEF) developed after treatment for an abdominal aortic aneurysm (AAA) is a rare but usually fatal complication. We report a rare case of AEF bleeding after endovascular stent grafting for AAA which was managed angiographically. An 81-year-old man presented with hematochezia and acute abdominal pain for 1 day ago. Four years ago, an aortic stent was implanted in the infrarenal aorta for AAA. Endoscopies were performed to evaluate the hematochezia. Evidence of gastrointestinal bleeding was observed, but a clear bleeding point was not detected on upper endoscopy and colonoscopy. Contrast-enhanced computed tomography performed subsequently showed that the bleeding point was located in the fourth portion of the duodenum as an AEF caused by an inflammatory process in the stent-graft. Intra-arterial angiography showed a massive contrast leakage into the bowel via a small fistula from around the aortic stent graft site. Embolization was successfully performed by injecting a mixture of glue and lipiodol into the AEF tract. The patient was discharged with no evidence of gastrointestinal bleeding after the embolization. (Korean J Gastroenterol 2013;61:230-233).

We present the case of a 68 year old Caucasian woman, in extremis, with left hemiparesis and right hemothorax, in hypovolemic shock, secondary to a blow-out of a large penetrating ulcer at the junction of innominate trunk and aortic arch. She underwent interposition graft replacement of innominate trunk and repair of aortic arch, on cardiopulmonary bypass, employing total circulatory arrest and selective antegrade cerebral perfusion and had total resolution of hemiparesis. She, however, represented, 6 months later, with threatened exsanguination after a sternal wire cheese-wired through the sternum and perforated the anteriorly lying innominate graft. Following successful repair, she was found to have an old intramural hematoma of distal arch and descending thoracic aorta and changes suggestive of chronic dissection of the whole of abdominal aorta. This was managed conservatively.We believe this patient's presentation initially with a spontaneous innominate blow-out, cardiogenic shock, hemothorax and hemiparesis, and later with cheese-wire perforation of the innominate graft is unique. Her surgical rescue at both presentations was equally unusual, and without surgical precedent to the best of our knowledge. Was the initial innominate blow-out the result of localised innominate dissection, or more unusually, part of retrograde descending thoracic dissection with skip penetration of innominate artery and sparing of the intervening arch? Was it secondary to the minor fall she had sustained 1 week prior to the event, resulting in a false aneurysm or a contained hematoma next to the innominate artery? More intriguingly, did diffuse aortopathy underpin these diverse etiologies and result in penetrating intimal ulcer with blow out in the innominate artery, intramural hematoma in the arch and descending thoracic aorta and dissection in abdominal aorta at different points in time?We review the current literature for these unusual afflictions of innominate trunk and its origin from the arch of aorta.

The prevalence of abdominal aortic aneurysm (AAA) and its risk factors are well known in Western countries but few data are available from low- and middle- income countries. We are not aware of systematically collected population- based data on AAA in the African region. We evaluated the prevalence of AAA in a population- based cardiovascular survey conducted in the Republic of Seychelles in 2004 (Indian Ocean, African region). Among the 353 participants aged 50 to 64 years and screened with ultrasound, the prevalence of AAA was 0.3% (95% CI: 0- 0.9) and the prevalence of ectatic dilatations of the abdominal aorta was 1.5% (95% CI: 0.2- 2.8). The prevalence of AAA in the general population seemed lower in Seychelles than in Western countries, despite a high prevalence in Seychelles of risk factors of AAA, such as smoking (in men), high blood pressure and hypercholesterolaemia.

Abdominal aortic aneurysms (AAAs) are defined as abnormal dilatation of the abdominal aorta and are potential to catastrophic complications. With the advent of multidetector computed tomography (MDCT), this diagnostic modality has virtually replaced conventional angiography in many circumstances and has become an integral part of the evaluation of AAA. Its ability to assess the peri-aortic soft tissue and the exact extension of aneurysm as well as its excellent vascular opacification and multiplanar reconstruction make computed tomography angiography the best suited imaging modality for not only detecting AAA but also evaluating its various complications. In this pictorial essay, we intend to demonstrate the spectrum of MDCT findings in AAA and its various consequences including impending rupture, contained rupture, rupture, aorto-caval fistula, aorto-left renal vein fistula, aorto-enteric fistula, and infection. Familiarity with the characteristic imaging features of AAA is essential for clinical radiologists and also referring physicians for the prompt diagnosis of life-threatening complications.