Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm: A Comprehensive Review

Abdominal aortic aneurysm (AAA) can be defined as an abnormal, progressive dilatation of the abdominal aorta, carrying a substantial risk for fatal aneurysmal rupture. Endovascular aneurysmal repair (EVAR) for AAA is a minimally invasive endovascular procedure that involves the placement of a bifurcated or tubular stent-graft over the AAA to exclude the aneurysm from arterial circulation. In contrast to open surgical repair, EVAR only requires a stab incision, shorter procedure time, and early recovery. Although EVAR seems to be an attractive solution with many advantages for AAA repair, there are detailed requirements and many important aspects should be understood before the procedure. In this comprehensive review, fundamental information regarding AAA and EVAR is presented.

Diagnosis and Treatment of Lower Extremity Deep Vein Thrombosis: Korean Practice Guidelines

Lower extremity deep vein thrombosis is a serious medical condition that can result in death or major disability due to pulmonary embolism or post-thrombotic syndrome. Appropriate diagnosis and treatment are required to improve symptoms and salvage the affected limb. Early thrombus clearance rapidly resolves symptoms related to venous obstruction, restores valve function and reduces the incidence of post-thrombotic syndrome. Recently, endovascular treatment has been established as a standard method for early thrombus removal. However, there are a variety of views regarding the indications and procedures among medical institutions and operators. Therefore, we intend to provide evidence-based guidelines for diagnosis and treatment of lower extremity deep vein thrombosis by multidisciplinary consensus. These guidelines are the result of a close collaboration between interventional radiologists and vascular surgeons. The goals of these guidelines are to improve treatment, to serve as a guide to the clinician, and consequently to contribute to public health care.

A Case of Pulmonary Capillary Hemangiomatosis-Like Lesion Followed for Seven Years / 결핵및호흡기질환

Pulmonary capillary hemangiomatosis (PCH) is a rare disease of unknown etiology that is characterized by nodules composed of infiltrating capillary blood vessels. Herein, we describe a case of a PCH-like lesion that was detected by chest computed tomography. Transthoracic needle aspiration resulted in life-threatening hemorrhage. The patient was followed for seven years. He remained in good health and a follow up image showed little interval change.

Retrograde Tempofilter II(TM) Placement within the Superior Vena Cava in a Patient with Acute Upper Extremity Deep Venous Thrombosis: the Filter Stands on Its Head

The Tempofilter II is a widely used temporary vena cava filter. Its unique design, which includes a long tethering catheter with a subcutaneous anchor, facilitates the deployment and retrieval of the device. Despite this, the Tempofilter II has been used only in the inferior vena cava of patients with lower extremity deep venous thrombosis. In this article, we present a case of superior vena cava filtering using the Tempofilter II in patients with upper extremity deep venous thrombosis.

Endovascular Stent Placement for the Treatment of Superficial Femoral Artery Stenoses and Occlusions

PURPOSE: The aim of this study was to evaluate effectiveness of an endovascular stent placement in the treatment of superficial femoral artery stenoses and occlusions. MATERIALS AND METHODS: An angioplasty and stent placement was performed in forty four patients (42 men and 2 women; mean age: 71.2 years; age range: 50-82 years). A total of 27 patients were diagnosed with intermittent claudication, in addition to 8 patients with resting pain, and 9 patients with gangrene. A follow-up evaluation accompanied with a physical examination, catheter angiography, and a color Doppler sonography was performed. The patency rates were analyzed after 3 months, 6 months, 1 year and 2 years. The predictors of restenosis, according to the clinical and anatomical classification, risk factors, as well as the correlation of stent fracture and restenosis were analyzed. RESULTS: Initial technical success was achieved in all patients. The stent placement resulted in an initial improvement of the clinical category in more than one level for 95.5% of cases. Over the course of the follow-up period (mean: 17 months; range, 1-106 months), restenosis occurred in 16 patients (36.4%). The highest patency rates were 87.9% after 3 months, 81.5% after 6 months, 78.0% after 1 year, 54.2% after 2 years, and 46.0% after 3 years. No significant difference was found for the patency rates as a function of the clinical and anatomical classifications, or the risk factors. A stent fracture was identified on only two occasions; however, no clinical symptoms or good intra-stent blood flow was observed in a follow-up angiography. CONCLUSION: A mid-term patency after the stent placements for superficial femoral artery stenoses and occlusions was found to be unfavorable despite an initial success rate. Consequently, greater clinical experience and analysis is necessary.

The Effects of Trimetazidine on the Enhancement Pattern of Multi-detector Computed Tomography in a Porcine Myocardial Infarction Model

BACKGROUND AND OBJECTIVES: There is increasing evidence to suggest that trimetazidine (TMZ) has the ability to improve ischemic heart failure by way of optimizing the heart's energy metabolism. The aim of this study was to examine the changes of the myocardial enhancement pattern by using two-phase, contrast enhanced, ECG-gated, multi-detector computed tomography (MDCT) after the administration of TMZ in a porcine myocardial infarction model. SUBJECTS AND METHODS: The porcine myocardial infarction model was created by balloon occlusion of the left anterior descending coronary artery. We randomized the swine into two groups: group I (n=7: aspirin only) and group II (n=7: aspirin plus 1 mg/kg TMZ for 4 weeks). Echocardiography and MDCT were performed and the ejection fraction (EF, %), end-systolic volume (ESV, mL) and end-diastolic volume (EDV, mL) were measured at 28 days after induction of myocardial infarction. Three enhancement patterns, including the early arterial phase defect (ED), the 4-min late enhancement (LE) and the residual defect (RD), were also investigated and those were described as class I [ED (-), RD (-), LE (+/-)], class II [ED (+), RD (-), LE (+)], and class III [ED (+), RD (+), LE (+)]. We performed histopathologic examination after sacrificing the animals. RESULTS: The baseline and follow-up echocardiography at 4 weeks after the induction of MI demonstrated no significant differences between the two groups. The LV indices by MDCT were also similar between the two groups (group I: EF, ESV and EDV=46.0+/-12.5%, 35.9+/-23.0 mL and 69.0+/-40.2 mL, respectively, group II: EF, ESV and EDV=49.8+/-13.2%, 43.8+/-23.1 mL and 82.8+/-24.6 mL, respectively, p=NS). The percent wall thickness was similar (69.1+/-19.6% vs. 64.9+/-10.5%, respectively, p=NS), but the enhancement pattern was different between the two groups (group I: class I, II and III=0 (0%), 0 (0%): and 7 (100%) respectively, group II: class I, II and III=0 (0%), 2 (28.6%) and 5 (71.4%), respectively, p<0.001). The volume of tissue that lacked triphenyl tetrazolium chloride was similar between two groups (8.4+/-1.9% vs. 7.3+/-2.6%, respectively, p=NS). CONCLUSION: TMZ administration produced different enhancement patterns on MDCT. This result suggests that TMZ administration can reduce the residual defect in a porcine myocardial infarction model. Although further experiments are needed for determining the effect of TMZ on reducing the irreversible area of infarcted myocardium, this is the first report that proved the beneficial effect of TMZ by performing MDCT.

Hepatic Perfusion Disorders: A Pictorial Review of CT and MR Imaging

The liver has a unique dual blood supply through the portal vein and the hepatic artery. There are several communications between these two vessels under various conditions such as in hepatic tumors, trauma and liver cirrhosis, vascular compromise, among others. When vascular compromise occurs, this dual blood supply system can cause changes in the volume of blood flow in individual vessels or even in the direction of blood flow. With rapid image acquisition and increased resolution available in multislice CT and MR imaging, hepatic perfusion disorders are now more frequently encountered than in the past. Familiarity with imaging findings of these perfusion disorders will be helpful in characterizing focal hepatic lesions and will also help to avoid false positive diagnoses.

Radio-frequency Ablation in Patients with Malignant Hepatic Tumor and Experimental Model: Comparison of Expandable Needle and Water-Cooled Needle

PURPOSE: The purpose of this study was to compare the shape and volume of the radio-frequency induced lesions produced by two commercially available radio-frequency ablation (RFA) systems, the expandable and cooled-tip needles, in clinical patients and an experimental model. MATERIALS AND METHODS: A twelve-array anchor expandable needle electrode and a single cooled-tip needle electrode were used to treat hepatic tumors with a single session in 23 patients (20 hepatocellular carcinomas and 3 hepatic metastases) and fourteen patients (10 hepatocellular carcinomas and 4 hepatic metastases), respectively. Twenty RFA induced lesions were created with each system in 10 explanted bovine livers. The shape of the RFA induced lesions were divided into oval lesions along or perpendicular to the axis of the electrode and spherical lesions, and we then calculated the volumes of the RFA induced lesions. RESULTS: Fourteen (61%) lesions of the 23 patients treated with the expandable system were oval perpendicular to the axis of the electrode and nine (39%) of the lesions were spherical. All the lesions (100%) of the 14 patients treated with the cooled-tip needle were oval along the axis of the electrode. In the ex vivo bovine livers, the shape of the all RFA induced lesions was oval perpendicular to the axis of the electrode for the expandable needle, and oval along the axis of the electrode for the cooled-tip needle. The mean diameter and volume of the RFA induced lesions in the patients were 3.35+/-0.56cm and 19.9+/-6.53 cm3, respectively, for the expandable needle and 3.58+/-0.78 cm and 23.19+/-5.27 cm3, respectively, for the cooled-tip needle. In the ex vivo model, the mean diameter and volume of RFA induced lesions were 3.41+/-0.59 cm and 26.59+/-8.02 cm3, respectively, for the expandable needle, and 4.04+/-0.65 cm and 33.82+/-6.16 cm3, respectively, for the cooled-tip needle (p<0.05). CONCLUSION:These results indicate that the shape of RFA induced lesions with the expandable needle were oval perpendicular to the axis of the electrode but those with the cooled-tip needle were oval along the axis of the electrode in both the clinical and experimental models. The cooled-tip needle induced significantly larger lesions than the expandable needle in the clinical patients and the experimental model. We need to consider these characteristic findings for RFA when we are performing such procedures.

Diagnostic Usefulness of Perilesional Edema around Intracerebral Hemorrhage in Predicting Underlying Causes

PURPOSE: We attempted to evaluate the diagnostic usefulness of the degree of perilesional edema around intracerebral hematoma in predicting the underlying cause. MATERIALS AND METHODS: This study included 54 patients with intracerebral hematoma for whom the underlying cause was confirmed by biopsy, radiological or clinical methods. Cases of subarachnoid hemorrhage, hemorrhagic transformation of cerebral infarction and intraventricular hemorrhage were excluded. The lesion size was defined as the average value of the longest axis and the axis perpendicular to this. The size of the perilesional edema was defined as the longest width of the edema. In all cases, the sizes of the lesion and edema were measured on the T2 weighted image. We defined the edema ratio as the edema size divided by the lesion size. RESULTS:23 cases were diagnosed as intracerebral hemorrhage due to neoplastic conditions, such as metastasis (n=17), glioblastoma (n=5), hemangioblastoma(n=1). 31 cases were caused by non-neoplastic conditions, such as spontaneous hypertensive hemorrhage (n=23), arteriovenous malformation (n=4), cavernous angioma (n=3), and moya-moya disease (n=1). In fourteen cases, which were confirmed as malignant intracerebral hemorrhage, the edema ratio was more than 100%. Of the other cases, only 8 were confirmed as malignant intracerebral hemorrhage. It was found that the larger the edema ratio, the more malignant the intracerebral hemorrhage, and this result was statistically significant (p<0.001). CONCLUSION: Measurement of perilesional edema and the intracerebral hematoma ratio may be useful in predicting the underlying causes.

Acute Cerebral Infarction in a Rabbit Model: Perfusion and Diffusion MR Imaging

PURPOSE: The present study was undertaken to evaluate the usefulness of cerebral diffusion (DWI) and perfusion MR imaging (PWI) in rabbit models with hyperacute cerebral ischemic infarction. MATERIALS AND METHODS: Experimental cerebral infarction were induced by direct injection of mixture of Histoacryl glue, lipiodol, and tungsten powder into the internal cerebral artery of 6 New-Zealand white rabbits, and they underwent conventional T1 and T2 weighted MR imaging, DWI, and PWI within 1 hour after the occlusion of internal cerebral artery. The PWI scan for each rabbit was obtained at the level of lateral ventricle and 1cm cranial to the basal ganglia. By postprocessing using special imaging software, perfusion images including cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps were obtained. The detection of infarcted lesion were evaluated on both perfusion maps and DWI. MTT difference time were measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. RESULTS: In all rabbits, there was no abnormal signal intensity on T2WI. But on DWI, abnormal high signal intensity, suggesting cerebral infarction, were detected in all rabbits. PWI (rCBV, CBF, and MTT map) also showed perfusion defect in all rabbits. In four rabbits, the calculated square of perfusion defect in MTT map is larger than that of CBF map and in two rabbits, the calculated size of perfusion defect in MTT map and CBF map is same. Any rabbits do not show larger perfusion defect on CBF map than MTT map. In comparison between CBF map and DWI, 3 rabbits show larger square of lesion on CBF map than on DWI. The others shows same square of lesion on both technique. The size of lesion shown in 6 MTT map were larger than DWI. In three cases, the size of lesion shown in CBF map is equal to DWI. But these were smaller than MTT map. The calculated square of lesion in CBF map, equal to that of DWI and smaller than MTT map was three. And in one case, the calculated square of perfusion defect in MTT map was largest, and that of DWI was smallest. CONCLUSION: DWI and PWI may be useful in diagnosing hyperacute cerebral ischemic infarction and in evaluating the cerebral hemodynamics in the rabbits.

Functional MR Imaging Using BOLD Technique in Patients with Brain Tumors

PURPOSE: To reveal clinical usefulness of functional MRI (fMRI) using sensorymotor and language stimuli for demonstrating anatomic relationship between sensorimotor or language cortices and lesions in the planning of brain tumor surgery. MATERIALS AND METHODS: This study included 12 right-handed patients with brain tumors in or around sensorimotor or language cortices. Eleven patients were evaluated with primary motor and sensory stimuli. Of these patients, six patients were also evaluated with language stimuli. One patient was evaluated with language stimuli only. For fMR imaging, a 1.5T scanner was used and the EPI BOLD technique was employed. For postprocessing image, the SPM99 program and a program made by our department was utilized. We evaluated whether sensorimotor and language stimuli activate sensorimotor and language cortices. And also, clinical efficacy of revealing anatomic relationship between cerebral cortices and lesions for planning neurosurgical operation were evaluated. Finally, we compared post-operative neurologic function with pre-operative neurologic function in same patients. RESULTS: The fMRI examination was successful in identifying the functional cortices and depicting anatomic relationship between functional cortices and lesions in all patients. In nine patients of 11 patients with identified sensorimotor cortices, postoperative grade of manual motor test was not changed, compared with preoperative grade. Whereas postoperative improved than preoperative grade in one patient of remaining two patients, postoperative aggravated than preoperative grade in the other. This result was due to atherosclerotic lacunar infarction, regardless of tumor resection. Postoperative deficit of language function was not found in seven patients with identified language cortices. CONCLUSION: fMRI could be a helpful method for determining the best approach to neurosurgical treatment in patients with brain tumors in or around sensorimotor or language cortices.

Diffusion-Weighted MR Imaging of Spinal Cord Infarction

PURPOSE: To evaluate the usefulness of diffusion-weighted imaging(DWI) and quantitative apparent diffusion coefficient (ADC) maps in the patients with spinal cord infarction. MATERIALS AND METHODS: We studied 6 patients presented symptoms with spinal cord infarction, retrospectively(3 men and 3 women). We obtained multi-shot echo planar-based, DWI using 1.5T MR scanner at 5.4 mean days after the onset of ischemic symptoms. In six patients, signal intensity was acquired at conventional b value (1000s/mm2). The ADC value for the normal spinal cord and for infarcted lesions was measured from the trace ADC maps by using regions of interest positioned over the spinal cord. We analyzed signal intensity of lesion on MRI and DWI, and compared with ADC values in infarcted lesions and normal site. RESULTS: T1-weighted MR image showed iso-signal intensity in four of six patients and low signal intensity in two of six. T2-weighted MR image demonstrated high signal intensity in all of six. All DWI were considered to be diagnostic. All of six depicted a bright signal intensity on DWI. ADC values of infarcted lesion were measured lower than that of normal spinal cord on ADC map. The differences in ADC values between infarcted and normal spinal cord were significantly different (p<0.05). CONCLUSION: It is possible to obtain DWI and ADC map of the spinal cord and DWI may be useful in the early diagnosis and localization of lesion site in patients with spinal cord infarction.