Mycotic Pseudoaneurysm After Kidney Transplantation: Two Case Reports.

BACKGROUND: Vascular complications after kidney transplantation may cause allograft loss. Here, we describe 2 patients with extrarenal mycotic pseudoaneurysm after kidney transplantation. PATIENTS: Patient 1 was a 54-year-old man who developed pseudoaneurysm 60 days after transplantation, and patient 2 was a 48-year-old woman who was diagnosed with a pseudoaneurysm 5 months after transplantation. RESULTS: Patient 1 had a deceased-donor kidney transplant with end-to-side external iliac arterial anastomosis that was reconstructed 8 days after transplantation owing to rupture and major bleeding. At 60 days after transplantation, he had high serum creatinine level and Doppler ultrasonography showed a pseudoaneurysm of the arterial graft anastomosis and postanastomotic renal artery stenosis. Treatment included surgical excision of the pseudoaneurysm, vascular reconstruction, and fluconazole, with mycologic culture of the resected pseudoaneurysm showing Candida albicans. Patient 2 developed nondisabling intermittent claudication at 5 months after kidney transplantation, with a pseudoaneurysm subsequently observed on Doppler ultrasonography and computerized tomographic angiography. Treatment included renal artery thrombectomy and common iliac bypass to the hilar donor renal artery with inverted ipsilateral long saphenous vein. Operative samples showed C albicans, and she was treated with fluconazole. Both patients had satisfactory outcomes, and both kidney allografts were preserved. CONCLUSIONS: Extrarenal mycotic pseudoaneurysms after kidney transplantation require a high index of suspicion for early diagnosis, and preservation of the kidney graft may be achieved with the use of surgical treatment and antifungal therapy.

Acute acalculous cholecystitis as a rare manifestation of chronic mesenteric ischemia. A case report.

INTRODUCTION: Symptomatic chronic mesenteric ischemia (CMI) is an uncommon condition that usually presents with intestinal angina, sitophobia and unintentional weight loss. Acute acalculous cholecystitis (AAC) has very rarely been described in the settings of CMI. PRESENTATION OF CASE: We describe a case of a 73year old man that developed an AAC as a complication of CMI. The patient underwent a simultaneous cholecystectomy and open aortic revascularization which was successful. At 24 months of follow-up the patient is clinically well and regained weight. DISCUSSION: Ischemia has been considered an important etiology for the development of AAC. In the settings of CMI, an AAC might develop has a herald sign of progression to acute mesenteric ischemia and infarction, as the cystic artery is a terminal artery with no collateral network. Performing the aortic revascularization simultaneously with the cholecystectomy might prevent this possible fatal outcome. CONCLUSION: This case reinforces aortic and visceral occlusive disease as a possible risk factor for the development of AAC, and discusses the treatment controversies when managing both conditions simultaneously.

Atherosclerotic plaque tissue characterization in 2D ultrasound longitudinal carotid scans for automated classification: a paradigm for stroke risk assessment.

In the case of carotid atherosclerosis, to avoid unnecessary surgeries in asymptomatic patients, it is necessary to develop a technique to effectively differentiate symptomatic and asymptomatic plaques. In this paper, we have presented a data mining framework that characterizes the textural differences in these two classes using several grayscale features based on a novel combination of trace transform and fuzzy texture. The features extracted from the delineated plaque regions in B-mode ultrasound images were used to train several classifiers in order to prepare them for classification of new test plaques. Our CAD system was evaluated using two different databases consisting of 146 (44 symptomatic to 102 asymptomatic) and 346 (196 symptomatic and 150 asymptomatic) images. Both these databases differ in the way the ground truth was determined. We obtained classification accuracies of 93.1 and 85.3 %, respectively. The techniques are low cost, easily implementable, objective, and non-invasive. For more objective analysis, we have also developed novel integrated indices using a combination of significant features.

ESVS guidelines. Invasive treatment for carotid stenosis: indications, techniques.

The European Society for Vascular Surgery brought together a group of experts in the field of carotid artery disease to produce updated guidelines for the invasive treatment of carotid disease. The recommendations were rated according to the level of evidence. Carotid endarterectomy (CEA) is recommended in symptomatic patients with >50% stenosis if the perioperative stroke/death rate is <6% [A], preferably within 2 weeks of the patient's last symptoms [A]. CEA is also recommended in asymptomatic men <75 years old with 70-99% stenosis if the perioperative stroke/death risk is <3% [A]. The benefit from CEA in asymptomatic women is significantly less than in men [A]. CEA should therefore be considered only in younger, fit women [A]. Carotid patch angioplasty is preferable to primary closure [A]. Aspirin at a dose of 75-325 mg daily and statins should be given before, during and following CEA. [A] Carotid artery stenting (CAS) should be performed only in high-risk for CEA patients, in high-volume centres with documented low peri-operative stroke and death rates or inside a randomized controlled trial [C]. CAS should be performed under dual antiplatelet treatment with aspirin and clopidogrel [A]. Carotid protection devices are probably of benefit [C].

Echolucency of carotid plaques correlates with plaque cellularity.

OBJECTIVE: To analyse the relationship between carotid plaque echolucency and cellularity. METHODS: Carotid plaques (14 symptomatic and 16 asymptomatic) were snap frozen after endarterectomy and defined on the basis of their grey-scale-median (GSM), obtained from pre-operative high-definition ultrasonography, as either echolucent (<32) or echogenic (>or=32). DNA and total soluble protein were determined to assess cellularity. RESULTS: After correcting for wet weight, symptomatic plaques had significantly more DNA (0.400 +/- 0.07 vs 0.335 +/- 0.07 mg/g; p = 0.03) and soluble protein (34.1 +/- 6.6 vs 29.7 +/- 3.4 mg/g; p = 0.03) than asymptomatic plaques. Predominantly echolucent (Grey-Weale classification) plaques had more DNA (0.404 +/- 0.06 vs 0.332 +/- 0.08 mg/g; p = 0.03) than echogenic plaques. Plaques with GSM < 32 also had more DNA (0.386 +/- 0.08 vs 0.319 +/- 0.06 mg/g; p = 0.04) and soluble protein (34.7 +/- 7.3 vs 29.6 +/- 4.2 mg/g; p = 0.03) than those with GSM >or= 32. Inverse relations were found between GSM and plaque DNA (r = -0.47; p = 0.02) and soluble protein (r = -0.45; p = 0.02) as well as between age and DNA (r = 0.39; p = 0.04) and soluble protein (r = -0.50; p = 0.003). CONCLUSIONS: Echolucency of carotid plaques as assessed by ultrasonography reflects plaque cellularity. This observation support the notion that ultrasonography can be used to identify high-risk plaques and evaluate effect of interventions on plaque structure.

Ultrasonographic risk score of carotid plaques.

OBJECTIVE: to determine the relative significance of ultrasonographic parameters of carotid plaques to develop an Activity Index (AI) which could correlate with clinical findings. METHOD: two hundred and fifteen plaques in 141 patients underwent ultrasonography and computer-assisted structural analysis. In half the patients (group 1), plaques were classified as either homogeneous and heterogeneous and ultrasonographic appearances related symptomatic (SP) or asymptomatic (AP) station. The probability of SP for each ultrasound parameter was used to define an Activity Index (AI). The AI was then applied the second half of patients (Group 2) to assess the value of AI in determining symptomatic station. RESULTS: the parameters with highest morbility were surface disruption, severe stenosis and low grey scale median and, additionally in heterogenous plaques heterogeneity and the presence of a juxta-luminal echolucent area. The power in group 2 of AI to identify symptomatic plaques was determined. Mean AI was for SP-75 (41-100) and for AP-43 (22-100); 78% of SP have AI>60 and 70% of AP have AI<50. The cut-off point between the two groups was 52. ROC curve analysis of the AI were obtained to determine its diagnostic accuracy. CONCLUSION: Activity Index is an objective parameter of plaque echostructure that positively correlates with symptoms. AI may contribute to better selection for treatment of patients with carotid artery disease.

Computer-assisted carotid plaque analysis: characteristics of plaques associated with cerebrovascular symptoms and cerebral infarction.

OBJECTIVE: to correlate the echostructural characteristics of carotid plaques with neurological symptoms and cerebral infarcts. MATERIALS: one hundred and five plaques were studied in 74 patients by colour-flow duplex ultrasound: 39 were symptomatic and 37 were associated with brain infarction on CT scanning. METHODS: the images were digitalised for computer-assisted image standardisation and divided in homogenous (n=67) and heterogenous (n=38) groups. Parameters of the plaque image were analysed. RESULTS: global echogenicity was significantly lower in symptomatic and in CT(+)plaques (p<0.05). For homogenous plaques, an echogenic cap (EC) was visualised in 8.3% of symptomatic vs. 33.9% of asymptomatic (p<0. 05) and in 7.7% for plaques that were CT(+)vs. 37.7% for CT(-)(p<0. 05). Surface disruption was visualised in 50% of symptomatic vs. 8. 5% of asymptomatic (p=0.002) and in 46% of CT(+)vs. 9.4% of CT(-)plaques (p=0.002). For heterogenous plaques, the echolucent region was juxtaluminal in 67% of symptomatic and CT(+)plaques vs. 33% in asymptomatic and CT(-)(p<0.01). CONCLUSION: echolucent plaques are associated with a higher neurological risk. In homogenous plaques the absence of an echogenic cap and disruption of the plaque surface also correlates with symptoms. In heterogenous plaques, juxtaluminal location of the echolucent region is an additional marker of increased risk.

[Atheroma plaque of the carotid bifurcation: how to identify an "active" lesion?]. / Placa de ateroma da bifurcação carotídea: como identificar a lesão "activa"?

UNLABELLED: The identification of carotid atheromatous plaques associated to a higher neurologic risk may be important in therapeutic decision making for asymptomatic patients and symptomatic patients with 50%-70% stenosis. The introduction of high-definition ultrasonography (HDU) and computer-assisted image analysis provides the possibility of a standard, objective and detailed characterization of the structure of the carotid plaque. The aim of this study is to analyse the relationship between the ultrasonographic characteristics of a group of plaques and the risk of associated cerebrovascular events and cerebral infarction. MATERIAL: One hundred carotid bifurcation plaques (in 68 patients) were studied for the presence of ipsilateral cerebrovascular events. In 61 patients (87 plaques), a correlation with CT scan for the presence of cerebral infarction was possible. METHOD: The lesions were studied by HDU (ATL-HDI 3000) and digitalized for computer-assisted standardization of the image. The analysis included the appreciation of the histogram of the image gray-scale pixel distribution by use of commercial software Adobe Photoshop 3.0. The parameters analysed for global echogenicity were the median of the histogram and the percentage of percentile 40 hypoechogenic pixels (40). Statistical analysis was made with STATA 4.0 software with categorical variables analysed by chi-square and Fisher's exact test and continuous variables analysed by variance analysis and Student's t test. RESULTS: Thirty eight (38%) plaques were symptomatic and 34 (39.1%) were associated to cerebral infarction. The degree of stenosis was > 70% in 51%; between 50 and 69% in 27% and < 50% in 22%. The mean of the median and P40 values was 33.9 and 60.3% in the symptomatic and 46.8 (p = 0.005) and 46.6% (p = 0.001) in the asymptomatic plaques respectively. In the plaques associated to cerebral infarction, it was 32.7 and 61.6% respectively, and in the ones with negative CT scan, it was 44.6 (p = 0.005) and 48.1% (p = 0.002). The mean of the median in the plaques vs. degree of stenosis was: > 70%--33.3; 50-69%--45.1; < 49%--57.7 (p < 0.001). In the series the cut-off point for the median value was 32 and for P40 it was 43 (for any degree of stenosis): G1--plaques < 32 (echolucent); G2--plaques > 32 (echogenic). In G1 symptoms occurred in 60% of the plaques and in 26% of the plaques in G2 (p = 0.0001). CT scan was positive in 66% of the echolucent plaques and in 25% of the echogenic plaques (p = 0.0238). CONCLUSION: 1. The more echolucent plaques are associated with a significantly higher neurological risk. 2. The plaques associated with higher degrees of stenosis are more echolucent. 3. The use of a standard and objective methodology in the analysis of the echographic structure of carotid plaques is important and limits the known intra and inter-observer variability of subjective appreciation.

[Endovascular surgery: recanalization technics and stent(s)]. / Cirurgia endovascular: técnicas de recanalização e stent(s).

Endovascular surgery has experimented a great development in the last years owing to the technologic advances in fields as mechanical and Laser recanalization technics, low profile catheters, Stents and diagnostic image. In a review work we discuss the role of this therapeutic modality in the treatment of vascular disease. To the vascular surgeon it becomes essential to be prepared to perform this procedures; to the general practitioner it becomes important to know about endovascular surgery potentialities. We discuss historical and technical aspects as also two important and polemic subjects in endovascular interventions: recanalization technics and stents. The authors personal experience, which is the first in Portugal in the fields of laser recanalization technics and stents placements, has been presented in several meetings and here is illustrated with one of our cases.

[Neodymium--Yag laser in the recanalization of arterial occlusions]. / Neodymium--Yag Laser na recanalização das oclusões arteriais.

Failure of the guide-wire to recanalize some arterial total occlusion does not preclude balloon angioplasty. Nowadays there are recanalization devices such as the mechanical atherectomy and Lasers. The following report describes the successful use of the Nd: YG Laser in the recanalization of a common iliac artery total occlusion in a patient with claudication, rendering possible balloon angioplasty and a Palmaz Stent implantation, which is the first case performed in our country.

[The role of stents in endovascular surgery]. / O stent na cirurgia endovascular.

Stent appears as the most recent and revolutionary acquisition in Endovascular Surgery. It represents the percutaneous permanent placement of a Vascular prosthesis. We discuss its background and evolution, the several types as well as some of its characteristics as biocompatibility, trombogenicity and biomechanics. We also describe practical aspects concerning the placement procedure. It is also discussed the present day prespectives and the future.

[Carotid artery surgery in extracranial occlusive disease and cerebral ischemia. Early and late results]. / Cirurgia carotídea na doença oclusiva extracraneana e isquemia cerebral. Resultados precoces e tardios.

Carotid artery surgery became an established procedure for the treatment of cerebrovascular insufficiency associated with carotid artery stenosis and for the prevention of Stroke. 180 patients were consecutively treated because of occlusive disease of the carotid arteries: 152 (84%) had TIA's or reversible deficits, 11 (6.1%) had strokes with partial recovery, 16 (8.8%) asymptomatic carotid disease and 1 patient (0.5%) had global cerebral ischemia. The severity of occlusive disease was assessed by ECHO-DOPPLER, with or without colour mapping and by angiography: 21 had minimal lesions (less than 20%), 58 stenosis between 21-75%, 92 stenosis between 76-99% and 7 had complete occlusion of the carotid artery; 2 patients had aneurysmal disease 196 operations were performed; early mortality (less than 30 days) was 2.2% (4/180) and neurological morbidity 1.6% (3/180), the operative risk being 3.8%. Longterm results were assessed during a follow-up period extending to 132 months and were assessed by life-table analysis. Survival was 52.5%, 79.3% of the patients were fully asymptomatic during the follow-up but 89.2% were stroke-free, the incidence of stroke being 0.97%/year. These results compare favorably with data available from the natural history and confirm the efficacy of carotid artery reconstructive surgery for the prevention of stroke.

Intermittent sequential pneumatic compression of the legs in the prevention of venous stasis and postoperative deep venous thrombosis.

The optimal stimulus which produced the maximum increase in blood velocity in the femoral vein during compression of the lower limb with a sequential compression device (six chambers) was determined using Doppler ultrasound in 10 normal limbs. Pressures of 35, 30, and 20 mm Hg at the ankle, calf, and thigh, respectively, applied sequentially for 12 seconds produced a 240% increase in the peak blood velocity. Higher pressures did not increase velocity any further. A nonsequential device (one chamber) inflated at 35 mm Hg for 12 seconds produced only a180% increase in blood velocity. The efficacy of the sequential device to prevent deep venous thrombosis then was tested and compared with a single chamber device and small-dose subcutaneous heparin in a randomized, controlled clinical trial using the 125I-fibrinogen test. The results suggest that the sequential compression device is as effective as heparin during the period when it is used (the first 24 hours after operation) and more effective than a nonsequential device in preventing deep venous thrombosis proximal to the calf.