Treatment of a common iliac aneurysm by endovascular exclusion using the amplatzer vascular plug and femorofemoral crossover graft.

We report our initial experience using the Amplatzer Vascular Plug II (AVP2) in the treatment of a left common iliac aneurysm. Following investigation by computerized tomographic angiography and catheter angiography, a 79-year-old man was found to have a markedly tortuous iliac system, with a left common iliac artery aneurysm that measured 48 mm in maximal diameter. Due to the patient's age and comorbidities the surgical opinion was that conventional open repair was not suitable. However, due to the tortuous nature of the aneurysm and iliac vessels, standard endovascular repair, using either a bifurcated or an aorto-uni-iliac stent graft, was also not possible. A combined approach was used by embolizing the ipsilateral internal iliac artery using coils and excluding the aneurysm using two AVP2 occlusion devices, followed by femorofemoral crossover grafting. Total aneurysm occlusion was achieved using this method and this allowed the patient to have a much less invasive surgical procedure than with conventional open repair of common iliac aneurysms, thus avoiding potential comorbidity and mortality.

The potential role of optical coherence tomography in the evaluation of vulnerable carotid atheromatous plaques: a pilot study.

PURPOSE: The decision to intervene surgically in patients with carotid artery disease is based on the presence of symptoms, along with the severity of carotid artery stenosis as assessed by ultrasound or X-ray computed tomography (CT). Optical coherence tomography (OCT) is a relatively new imaging technique that offers potential in the identification of, as well as the distinction between, stable and unstable atherosclerotic plaques. The purpose of our study was to evaluate whether OCT can be used as a noninvasive diagnostic tool to reveal the morphology of carotid stenosis from the adventitial surface of the carotid artery. To achieve this aim, excised atheromatous plaques were scanned by OCT from the external surface. METHODS: Plaques removed at carotid endarterectomy were scanned by OCT from the external surface within 72 hr of surgery and then examined histologically. The images of the histologic slides and the scans were then compared. RESULTS: We examined 10 carotid endarterectomy specimens and were able to identify calcification, cholesterol crystal clefts, and lipid deposits in the OCT images with histologic correlation. The strong light scattering from the calcified tissue and cholesterol crystal clefts limited the depth of light penetration, making observation of the intimal surface and the detail of the fibrous cap difficult. However, we were able to confidently identify the absence of an atherosclerotic plaque by OCT scans even from the external surface. CONCLUSION: The results of this pilot study demonstrate that OCT can reveal the main features of carotid stenosis but that plaque vulnerability cannot be reliably and precisely assessed if scanned from the external surface with OCT in its present form.

Relationship of matrix metalloproteinases and macrophages to embolization during endoluminal carotid interventions.

PURPOSE: To investigate if relationships exist among macrophage infiltration, plasma matrix metalloproteinase (MMP) levels, and the number of emboli generated during endoluminal carotid interventions. METHODS: Carotid endarterectomy specimens excised as intact cylinders (n=27) were subjected to a standardized angioplasty procedure under radiological guidance in an ex vivo pulsatile flow model. Emboli collected in distal filters were counted and sized using microscopy. Preoperative plasma gelatinase activity was determined by gelatin zymography and quantified using image analysis software. Levels of tissue inhibitors of metalloproteinases (TIMP) 1 and 2 were determined by ELISA. Macrophages within postangioplasty plaques were analyzed using immunohistochemical staining for CD68 antigen and graded by a blinded examiner. Statistical analysis was performed using Spearman's rank correlation. RESULTS: The median number of emboli recorded during angioplasty was 104 (interquartile range 33.75-242.5, absolute range 13-1090). Plasma MMP-9 and MMP-2 levels correlated with emboli number (r=0.544 [p=0.003] and r=0.412, [p=0.033], respectively), while TIMP-1 and TIMP-2 levels did not. Macrophage infiltration within the plaques correlated with emboli number (r=0.722, p<0.001) and the plasma MMP-9 level (r=0.489, p=0.010). CONCLUSIONS: These data indicate that plaque macrophage infiltration may play a role in the generation of emboli during endoluminal carotid intervention, possibly via modulation of protease activity.

Multislice CT angiography in renal artery stent evaluation: prospective comparison with intra-arterial digital subtraction angiography.

PURPOSE: To assess the role of multislice computed tomography angiography (MCTA) in the evaluation of renal artery stents, using intra-arterial digital subtraction angiography (DSA) as the gold standard. METHODS: Twenty consecutive patients (15 men, 5 women) with 23 renal artery stents prospectively underwent both MCTA and DSA. Axial images, multiplanar reconstructions and maximum intensity projection images were used for diagnosis. The MCTA and DSA images were each interpreted without reference to the result of the other investigation. RESULTS: The three cases of restenosis on DSA were detected correctly by MCTA; in 19 cases where MCTA showed a fully patent stent, the DSA was also negative. Sensitivity and negative predictive value (NPV) of MCTA were therefore 100%. In four cases, MCTA showed apparently minimal disease which was not shown on DSA. These cases are taken as false positive giving a specificity of 80% and a positive predictive value of 43%. CONCLUSION: The high sensitivity and NPV suggest MCTA may be useful as a noninvasive screen for renal artery stent restenosis. MCTA detected mild disease in a few patients which was not confirmed on angiography.