Amount Of Contrast Medium Research Articles

Predictors for contrast media-induced nephropathy and long-term survival: Prospectively assessed data from the randomized controlled Dialysis-Versus-Diuresis (DVD) trial

Among the numerous studies concerning contrast media-induced nephropathy (CIN), there was no prospective trial that provided data on the long-term outcomes. To prospectively assess predictors of CIN and long-term outcomes of affected patients. Four hundred twelve consecutive patients with serum creatinine levels of 115 micromol/L to 309 micromol/L (1.3 mg/dL to 3.5 mg/dL) undergoing elective coronary angiography were included. Patients were randomly assigned to periprocedural hydration alone, hydration plus one-time hemodialysis or hydration plus N-acetylcysteine. Multivariate logistic regression identified the following as predictors of CIN within 72 h (equivalent to an increase in creatinine 44.2 micromol/L [0.5 mg/dL] or more) : prophylactic postprocedural hemodialysis (OR 2.86, 95% CI 1.07 to 7.69), use of angiotensin-converting enzyme inhibitors (OR 6.16, 95% CI 2.01 to 18.93), baseline glomerular filtration rate (OR 0.94, 95% CI 0.90 to 0.98) and the amount of contrast media given (OR 1.01, 95% CI 1.00 to 1.01). With regard to long-term outcome (mean follow-up 649 days), multivariate Cox regression models found elevated creatinine levels at 30 days (hazard rate ratio [HRR] 5.48, 95% CI 2.85 to 10.53), but not CIN within 72 h (HRR 1.12, 95% CI 0.63 to 2.02), to be associated with increased mortality. In addition, independent predictors for death during follow-up included left ventricular ejection fraction lower than 35% (HRR 4.01, 95% CI 2.22 to 7.26), serum phosphate (HRR 1.64, 95% CI 1.10 to 2.43) and hemoglobin (HRR 0.80, 95% CI 0.67 to 0.96). From the present prospective trial, performance of postprocedural hemodialysis, use of angiotensin-converting enzyme inhibitors, reduced baseline glomerular filtration rate and amount of contrast media were independent predictors of CIN within 72 h after catheterization. Assessing renal function after 30 days, rather than within 72 h, seemed to be more predictive for patients' long-term survival.

Abstract 893: Contrast Medium-Induced Renal Damage is Tightly Associated with Endothelial Injury in Patients

Background: Contrast-induced nephropathy (CIN) remains a common complication of radiographic procedures. We hypothesized that endothelial dysfunction is the main cause of CIN. To clarify whether contrast medium-induced renal damage is associated with endothelial injury, we measured microparticles derived from endothelial cells as markers of endothelial injury. Circulating microparticles are shed from cell surface respond to cell activation and apoptotic stimuli, reflecting the condition of damaged cells. Methods: Renal function of 35 adult patients was analyzed before and after the use of contrast medium for coronary angiography. Parameters for renal function and urinary 15-isoprostane F2t, a specific marker of oxidative stress were measured before and after radiocontrast administration. Flow cytometry was used to count circulating CD34 + microparticles, which is regarded as one of markers for endothelial damage. Results: The decrease of estimated glomerular filtration rate positively correlated with the amount of contrast medium (r=0.427; P=0.013). Urinary N-acetyl-beta-D-glucosaminidase, a marker of renal tubular injury, was increased after angiography (from 7.6+/− 6.8 to 9.1 +/− 6.0 U/g-CRE, P=0.011). Furthermore, urinary 15-isoprostane F2t positively correlated with the volume of contrast medium (r=0.421; P=0.012). CD34+ microparticle was significantly increased after angiography (1.3-fold increased from basal level, P=0.0017). The increase of CD34+ microparticle was associated with the insult of contrast medium, but not of the amount. Conclusion: Radiocontrast impaired renal function in accordant with the increase of oxidative stress. The release of CD34+ microparticle was also increased by use of radiocontrast. These data suggest that CIN is tightly associated with endothelial injury mediated by radiocontrast-induced oxidative stress.

Abstract 2275: The Association of Cardiac Catheterization Timing, Contrast Media Amount, and Preoperative Renal Function with Post Cardiac Surgery Acute Renal Failure and Mortality

Background The effect of cardiac catheterization timing, contrast media dose, and preoperative renal function on post cardiac surgery acute renal failure (ARF) prevalence is unclear. Methods and Results Data of 395 consecutive patients who underwent CABG were prospectively collected. Glomerular filtration rate (eGFR) was estimated by the CockcroftGault equation. Patients were divided into 3 groups according to the time between cardiac catheterization and surgery (Group I:≤1 day, Group II:>1 and ≤5 days, Group III:>5 days). Patients who underwent salvage operation, or were on dialysis before surgery were excluded. Multivariable analysis was used to identify risk factors for ARF (defined as 25% decrease from baseline of eGFR, and eGFR≤60ml/min on postoperative day 3). propensity score analysis was used to adjust differences in preoperative characteristics between groups. ARF developed in 13% of patients. Hospital mortality was 3.3% and was higher in patients who developed ARF (21%) vs those that did not (0.6%, p<0.001). Multivariable analysis identified operation within 24 hours of catheterization (OR=4), and eGFR<60ml/min up to 5 days from catheterization (OR=2.5) as independent predictors of ARF (p<0.05). The use of more than 1.4 ml/kg of contrast media in patients with eGFR<60ml/min predicted ARF as well (OR=5, p<0.001). Older age, lower weight, and lower preoperative hemoglobin levels were also associated with ARF. Conclusions Whenever possible, cardiac surgery should be delayed for at least 24 hours (preferably 5 days) from catheterization, especially in patients with low eGFR, and in those who received high dose of contrast media.

Ambulante, CT-gestützte lumbale Sympathikolyse bei Patienten mit schwerer pAVK: Einfluss auf die periphere Perfusion sowie die klinischen Beschwerden

The clinical improvements reported by patients after lumbar sympathicolysis have been verified and quantified by colour-coded duplex sonography (CCDS) in this study. CT-assisted lumbar sympathicolysis was performed on 136 patients (105 men, 31 women; mean age 66.1; range: 43-82 years) with PAOD (Fontaine stage II b-IV) on an outpatient basis after exhaustive surgical and interventional therapy. Puncture was performed via a dorsolateral approach, a 22 G Seibel-Grönemeyer Chiba biopsy needle was placed intercavovertebrally or interaortovertebrally at the level of the arch pedicle of the third lumbar vertebral body. A medication mixture consisting of 96% alcohol, 0.5% Carbostesin and added amounts of contrast medium was administered when the needle was correctly positioned. An average of 10 mL (6-12 mL) of the sympathicolytic agent was administered; in all cases only one side was treated per sitting. Before and around 120 min after the intervention, and 6 months post-intervention, the systolic and end-diastolic flow velocities, and blood volumes per minute were determined by CCDS. Additionally, the retroperitoneal space was examined by ultrasound after 6 months. The clinical outcome and the complications were assessed by a standardised questionnaire. In all patients, sympathicolysis was performed without technical complications. Starting on day 1 post-intervention, 4 patients complained of dysaesthesia in the inguinal and thigh area, another patient developed an erectile dysfunction although all these complications were completely reversible. 131/136 (96%) of the patients showed a significant increase in peripheral circulation immediately after the intervention, whereby a significant persistent effect was also seen in 120/136 (88%) after 6 months. In particular, patients in PAOD stages III and IV gained a clinical benefit. Lumbar sympathicolysis is a therapeutic option in severe PAOD that is low in complications, effective, minimally invasive and can be performed on an outpatient basis; it should be considered after angiographic-interventional and surgical measures have been exhausted. The significant clinical improvements can be explained in part by the improvement in perfusion as verified by CCDS.

Imaging of the Coronary Venous System: Validation of Three-Dimensional Rotational Venous Angiography Against Dual-Source Computed Tomography

Information on the anatomy of the cardiac venous system (CVS) is increasingly important for cardiac resynchronization therapy or percutaneous transvenous mitral valve annuloplasty. Three-dimensional (3D) imaging can further improve the understanding of the relationship of cardiac structures. This study was performed to validate the accuracy of rotational coronary sinus angiography (CSA) displaying the 3D anatomy of the CVS compared to ECG-gated, contrast-enhanced, cardiac dual-source computed tomography (DSCT). Five domestic pigs (60 kg) underwent DSCT using a standardized examination protocol. Using a standard C-arm for fluoroscopy, a rotational CSA was obtained and 3D-image reconstructions performed. Side branches were identified using both methods and enumerated. Vessel visibility was estimated for each side branch and great cardiac vein/anterior interventricular vein. Also, vessel diameters were measured at distinct landmarks, i.e., side branching. The amount of contrast medium was determined and the effective radiation exposure of both methods was calculated. There was no significant difference regarding the vessel diameter of the great cardiac vein/anterior interventricular vein or its side branches. Also, estimation of vessel visibility was not different between the two imaging modalities. Estimated radiation exposure and amount of contrast medium were lower for rotational CSA. In conclusion, a 3D reconstruction of rotational CSA images is possible. All parts of the CVS are well depicted, allowing a 3D overview of the CVS anatomy. On-site 3D visualization might improve decision making during cardiac interventions. In contrast to DSCT, rotational CSA does not demonstrate the anatomy of the mitral annulus or the course of the left circumflex artery.

Magnetic resonance angiography (MRA) in renally impaired patients: When and how

Magnetic resonance angiography (MRA) and NSF in renally impaired patients have a close relationship due to the frequent coincidence of vascular and renal pathologies, the relatively large amount of contrast media applied and the delayed excretion. The date of the first NSF cases described in literature falls into the development of multi-stationary MRA—an investigation that requested multiple bolus injections or one large bolus of the contrast agent. It is therefore easily understood that NSF was regarded initially as possible complication of MRA. A review on the history of MRA is presented and various techniques for MRA are described. While many neuroradiological indications can be solved by native MRA, most angiographic indications throughout the body rely on the application of intravenous contrast agents. The paper discusses options for alternative methods in vascular imaging and offers guidelines for patients with renal impairment. NSF must always be balanced versus the outcome of an investigation, respectively versus the outcome of a denied MRA. Moreover, in patients with chronic kidney disease (CKD) and a proper justification for a vascular investigation, neither CT angiography nor DSA should replace MRA. Restrictions in contrast media dose for CKD patients are mandatory and obviously reduce the risk of NSF. Gadolinium-based contrast agents with lower stability are now contraindicated in patients with reduced renal function. The role of blood pool agents is under evaluation. Since the awareness of the new disease grew over the last year, radiologists were able to reduce the number of newly diagnosed NSF cases by more careful consideration of contrast application and agent in renally impaired patients, which gives hope that NSF can be avoided by respecting some easy rules.

Influence of the Timing of Cardiac Catheterization and the Amount of Contrast Media on Acute Renal Failure After Cardiac Surgery

Postoperative acute renal failure (ARF) is not uncommon after cardiac surgery and after angiography. However, limited information exists regarding the influence of the interval between cardiac catheterization and subsequent cardiac surgery and amount of contrast agent used during this procedure on the occurrence of postoperative ARF. Data for 423 consecutive adult patients who underwent elective cardiac surgery after cardiac catheterization were examined retrospectively. The influence of interval between cardiac catheterization and cardiac surgery on postoperative ARF (defined as postoperative serum creatinine > or =2 times baseline and >2 mg/dl and/or need for renal replacement therapy) was evaluated using multivariable logistic regression. ARF occurred in 24 patients (5.7%). Median time to angiography was 2 days (interquartile range 1 to 4.5), and median dose of contrast used was 1.36 ml/kg (interquartile range 1.12 to 1.69). Surgery on the day of cardiac catheterization was independently associated with increased risk of ARF (adjusted odds ratio 3.1, 95% confidence interval 1.1 to 8.8). This risk of ARF was highest in patients who underwent surgery on the same day as angiography and with a dose of contrast higher than median (14.6%) and lowest when surgery was delayed beyond 1 day of angiography and contrast dose was median or less (2.4%; adjusted odds ratio for same-day surgery and dose higher than median 4.2, 95% confidence interval 1.2 to 14.2). Cardiac surgery performed on the day of cardiac catheterization and higher dose of contrast agent used were both independently associated with increased risk of postoperative ARF. In conclusion, these findings suggest that delaying cardiac surgery beyond 24 hours of exposure to contrast agents (when feasible) and minimizing the use of these agents have significant potential to decrease the incidence of postoperative ARF in patients undergoing elective cardiac surgery.

Contrast Enhancement in Cardiovascular MDCT: Effect of Body Weight, Height, Body Surface Area, Body Mass Index, and Obesity

The purpose of our study was to evaluate the effect of body weight, height, body surface area (BSA), body mass index (BMI), and obesity on aortic contrast enhancement in cardiac MDCT. Seventy-three consecutive patients underwent cardiac CT angiography on a 64-MDCT scanner. Seventy-five mL of contrast medium (350 mg I/mL) was injected at 4.5 mL/s, followed by a 40-mL saline flush at 4.5 mL/s. The scanning delay of CT was determined with a bolus tracking technique. Aortic attenuation was measured over the aortic-root lumen. BMI and BSA were calculated from the patient's body weight and height. The patients were divided into low-(BMI < 30) and high-(> or = 30) BMI groups. Associations of aortic attenuation with body weight, height, BMI, and BSA were evaluated with regression analysis and the Student's t test. Strong inverse correlations were seen between aortic attenuation and body weight (r = -0.73), height (r = -0.47), BMI (r = -0.63), and BSA (r = -0.74) (p < 0.001 for all). The regression formula of aortic attenuation versus body weight suggests that 1.0 mL/kg of contrast medium would yield a mean aortic attenuation of 355 H. The mean aortic attenuation was significantly higher in the low-BMI (352.6 +/- 59.1 H) than in the high-BMI (286.2 +/- 55.5 H) group. The regression formula for aortic attenuation on body weight was aortic attenuation = 586-3.1 body weight (p < 0.001) for the low-BMI group and aortic attenuation = 485-1.9 body weight (p < 0.001) for the high-BMI group, suggesting that the amount of contrast medium required with increased body weight is less in the high-BMI group. This group difference was less pronounced for the regression of aortic attenuation on BSA. To achieve a consistent contrast enhancement in cardiac CT angiography (CTA), contrast-medium dose should be adjusted with the body weight or the BSA (which accounts for both the body weight and height factors) to provide adjustment of iodine dose over a wide range of body sizes.

Adequacy of an early arterial phase low-volume contrast protocol in 64-detector computed tomography angiography for aortoiliac aneurysms

This retrospective study was conducted to determine whether a low-volume contrast medium protocol provides sufficient enhancement for 64-detector computed tomography angiography (CTA) in patients with aortoiliac aneurysms. Evaluated were 45 consecutive patients (6 women; mean age, 72 +/- 6 years) who were referred for aortoiliac computed tomography angiography between October 2005 and January 2007. Group A (22 patients; creatinine clearance, 64.2 +/- 8.1 mL/min) received 50 mL of the contrast agent. Group B (23 patients; creatinine clearance, 89.4 +/- 7.3 mL/min) received 100 mL of the contrast agent. The injection rate was 3.5 mL/s, followed by 30 mL of saline at 3.5 mL/s. Studies were performed on the same 64-detector computed tomography scanner using a real-time bolus-tracking technique. Quantitative analysis was performed by determination of mean vascular attenuation at 10 regions of interest from the suprarenal aorta to the common femoral artery by one reader blinded to type and amount of contrast agent and compared using the Student t test. Image quality according to a 4-point scale was assessed in consensus by two readers blinded to type and amount of contrast medium and compared using the Mann-Whitney test. Multivariable adjustments were performed using ordinal regression analysis. Mean total attenuation did not differ significantly between both groups (196.5 +/- 33.0 Hounsfield unit [HU] in group A and 203.1 +/- 44.2 HU in group B; P = .57 by univariate and P > .05 by multivariable analysis). Accordingly, attenuation at each region of interest was not significantly different (P > .35). Image quality was excellent or good in all patients. No significant differences in visual assessment were found comparing both contrast medium protocols (P > .05 by univariate and by multivariable analysis). Aortoiliac aneurysm imaging can be performed with substantially reduced amounts of contrast medium using 64-detector computed tomography angiography technology.

Magnetic‐Guided Percutaneous Coronary Intervention Enabled by Two‐Dimensional Guidewire Steering and Three‐Dimensional Virtual Angioscopy: Initial Experiences in Daily Clinical Practice

Percutaneous coronary intervention (PCI) has been broadly established and often includes highly complex stenoses that require difficult navigation. The purpose of this study is to assess the feasibility of a new magnetic navigation system (MNS) to enable intracoronary guidewire deployment and PCI in daily clinical practice and to compare the 2D guidance to the virtual 3D angioscopy feature. We included 30 consecutive patients (pt) in whom 36 coronary arteries were PCI targets. Patients were randomized to guidewire steering by either 2D guidance or virtual 3D angioscopy (33%). In 31/36 (86%) interventions the MNS guidewire successfully passed the culprit stenosis and the procedure was accomplished by PCI. In 5/30 pt an MNS multivessel intervention was performed. Three of 5 unsuccessful procedures failed due to an unsuccessful recanalization of a subtotal chronic occlusion including 1 pt who required surgical intervention. In 2/36 procedures the magnetic guided intervention was performed effectively after prior conventional failure related to complex anatomy. The contrast medium amount needed to position the magnetic guidewire was 60 +/- 101 mL in 2D accomplished interventions vs. 14 +/- 15 mL in 3D procedures (p < 0.05). In 3 pt the MNS did not harm the implanted pacemaker or defibrillator system. Magnetic guided PCI is useful in selected patients. In our experience, success is less likely in evidence of a subtotal occlusion.

頭部３Ｄ−ＣＴＡにおける造影法‐ＴＤＣから考える撮像時間を基準にした造影方法の検討‐

In three-dimensional CT angiography (3D-CTA), good reproducibility can be obtained by maintaining the maximum CT numbers (HU) at a specified level. However, the correlation between the scan time and the injection time showed that the maximum CT numbers increased and varied due to the additional contrast enhancement effect from recirculation of the injected contrast medium for longer injection times when the dose of iodinated contrast medium per unit time (mgI/s) was maintained at a specified level based on the time-density curve (TDC) of the phantom. The amount of contrast medium employed at our hospital has been optimized based on an iodinated contrast medium dose per unit time providing a contrast enhancement effect of 300 HU in the middle cerebral artery. Using this standard, a TDC phantom was employed to obtain an iodinated contrast medium dose per unit time, permitting equivalent maximum CT values (used as standard values) to be obtained by changing the injection time. A contrast-enhancement technique that accounts for the variation in the scan time was evaluated. Strong correlations were observed between the scan time and the injection time (R2=0.969) and between the injection time and the dose of iodinated contrast medium per unit body weight (R2=0.994). We conclude that adjusting the dose of iodinated contrast medium per unit body weight per unit time according to the scan time permits optimization of the contrast-enhancement technique.

Renal Insufficiency Following Contrast Media Administration Trial (REMEDIAL): A Randomized Comparison of 3 Preventive Strategies

Conclusion: A combination of volume supplementation by sodium bicarbonate plus N-acetylcysteine (NAC) provides better renal protection after contrast administration in patients with chronic kidney disease (CKD) than strategies of hydration with a combination of normal saline and NAC or the addition of ascorbic acid. Summary: The optimal strategy for preventing contrast agent–induced nephrotoxicity (CIN) in patients with CKD is uncertain. Guidelines suggest volume expansion with saline, along with use of low or iso-osmolar contrast agents and limits on the volume of contrast agent (Kidney Int 2006;69:S51-3). Additional strategies focus on the use of antioxidants because reactive oxygen species are considered an important pathophysiologic cause of CIN (Kidney Int 2005;68:14-22). Both NAC and ascorbic acid have antioxidant properties. The authors sought to determine efficiency in preventing CIN in patients with CKD after administration of contrast agents. Of 326 consecutive patients with CKD undergoing coronary or peripheral procedures, or both, 111 were assigned randomly to prophylactic administration of 0.9% saline infusion plus NAC, 107 to 0.9% saline plus ascorbic acid plus NAC, and 108 to sodium bicarbonate infusion plus NAC. All patients had an estimated glomerular filtration rate of <40 mL/min and a serum creatinine level >2 mg/dL. A contrast nephropathy risk score was calculated for each patient. An iso-osmolar, nonionic contrast agent (iodixanol) was used. A >25% increase in creatinine level 48 hours after the procedure was considered the primary end point of the study. Similar amounts of contrast media were administered to each group (P = .69), and contrast nephropathy risk scores were also similar (P = .21). In the saline plus NAC group, CIN occurred in 11 of 111 (9.9%). In the bicarbonate plus NAC group, CIN occurred in 2 of 108 (1.9%; P = .019). CIN occurred in 11 of 107 patients (10.3%) in the saline plus ascorbic acid plus NAC group (P = 1.00 vs saline plus NAC group). Comment: The study calls into question the concept of reactive oxygen species as an important pathophysiologic cause of CIN and suggests a different protective mechanism of action for bicarbonate. Additional studies will need to be performed to determine whether a combination of antioxidant therapy plus bicarbonate is even more efficacious than bicarbonate therapy alone.

Abstract 1690: Prevention of Contrast-Induced Nephropathy by Carperitide

Introduction: Contrast-induced nephropathy (CIN) remains as a common complication of angiographic procedure. Carperitide, an antagonist of secretion of rennin, aldosterone and vasopressin with natriuretic effects, has renal protective effects. Hypothesis: Carperitide may be effective in preventing CIN. Methods: We prospectively studied 170 consecutive patients with chronic renal failure (serum creatinine(SCr) concentration &gt;1.3mg/dl)who underwent coronary angiography. The patients were randomly assigned to either 1.3ml/kg/hr of lactated Ringer’s infusion plus carperitide 0.042μg/kg/min (Carperitide group N=86) or lactated Ringer’s infusion alone (Control group N=84). The administration was initiated 6 hours prior to the procedure and continued for 48 hours after angiography. The concentration of SCr and cystatin C were measured at baseline, 24 hours, 48 hours, 1 week, and 1 month following the angiography. Results: The SCr concentration increased gradually up to one month in the Control group, whereas remained almost unchanged in the Carperitide group (p=0.001 for the trend, Figure ). The cystatin C concentration also showed the same trend (p=0.013 for the trend, Figure ). When CIN was defined as an increase of ≥0.5 mg/dl or ≥25% in the SCr at 48 hours after angiography, CIN developed in 7 of 84 patients (8%) in the Control group and 1 of 86 patients (1%) in the Carperitide group (P=0.047). Multivariate analysis disclosed that carperitide infusion (OR 0.097, P=0.041) and quantity of contrast media (OR 14.06, P=0.004) were significantly related to the development of CIN. Conclusions: Carperitide is effective in preventing CIN in patients with chronic renal failure.

Gadolinium:Nonionic Contrast Media (1:1) Coronary Angiography in Patients With Impaired Renal Function

This study was to test safety and efficacy of 1:1 mixture of gadolinium:nonionic contrast media in avoiding contrast nephropathy during coronary angiography in patients with renal dysfunction. Although "off label" for x-ray angiography, gadolinium has drawn attention for its potential to avoid contrast nephropathy during coronary angiography. Initial data seem promising. Patients with a baseline creatinine of 1.5 mg/dl or more were included. In order to minimize contrast nephropathy risk, all patients were thoroughly hydrated and treated by N-acetylcysteine. After coronary angiography and/or percutaneous coronary intervention, renal function tests were remeasured on days 1, 2, and 3. A rise of 0.5 mg/dl or more in creatinine value in the following 3 days or the need for dialysis were considered as a contrast nephropathy event. Twenty-six patients were enrolled in this study. Ten were women and 16 were men. The mean age was 65.7 +/- 11. Baseline creatinine value was 2.47 +/- 0.74 mg/dl. The total amount of contrast medium used on 1:1 fashion was 57.1 +/- 27.2 ml. No procedure-related cardiac complication or contrast nephropathy event occurred in this study. Although there was a slight loss in image quality, we felt that the results were adequate for interpretation. Although "off label," using gadolinium contrast media in a 1:1 mixture with standard nonionic low osmolar contrast media seems to be a viable option in decreasing the likelihood of contrast nephropathy. Further evaluation appears to be warranted.

Retrospective Study of Rapid-Exchange Monorail Versus Over-the-Wire Technique for Femoropopliteal Angioplasty

The purpose of this study was to compare procedural outcome of rapid-exchange (RX) monorail versus conventional over-the-wire (OTW) technique for femoropopliteal angioplasty. Demographic data, procedure details, angioplasty success, and complications of 328 consecutive percutaneous transluminal angioplasties (PTAs) were collected from a prospective database and retrospectively analyzed. Procedure details included duration of fluoroscopy, area-dose product, amount of contrast agent, sheath sizes, access route, length of stenosis, presence of total occlusion, technical and anatomical success (residual stenosis < 30% in the absence of complications), need for bail-out stenting, and periprocedural complications. The RX technique alone was used in 102 of 328 cases (31%); the OTW technique, in 226 of 328 of cases (68%). Technical success was 98% for the RX versus 95.4% for the OTW technique (p = 0.2). A significantly greater number of stents had to be implanted due to angioplasty failure when the OTW technique was used (RX, 5.9%; OTW, 13.7%; p = 0.04). There were no significant differences in fluoroscopy time, dose-area product, or amount of contrast medium used. The RX system facilitated the use of smaller sheath sizes (5 Fr = 38% and 6 Fr = 59% for RX versus 5 Fr = 16.8% and > or = 6 Fr = 82.5% for OTW) but showed only a tendency toward lower overall complication rates (16.6% [17/102] in the RX group versus 19.9% [45/226] in the OTW group; p = 0.09). There was no effect on length of hospitalization. RX monorail systems were not associated with higher procedural costs when compared to conventional OTW technique. We conclude that RX monorail systems seem to enhance the technical success of femoropopliteal angioplasty. Although smaller sheath sizes can be used due to the lower profile of the RX systems, there is only a tendency toward lower complication rates.

CT Pulmonary Angiography and CT Venography: Factors Associated with Vessel Enhancement

The objective of our study was to determine factors associated with enhancement on CT pulmonary angiography and CT venography. Two hundred forty-two cases (83 men and 159 women; mean age, 63 years; age range, 21-92 years) underwent CT pulmonary angiography using a bolus-tracking technique; 189 cases subsequently underwent CT venography 3 minutes after the start of the contrast injection. Two different amounts of nonionic iodine contrast medium were administered: patients weighing > 50 kg who were undergoing both CT pulmonary angiography and CT venography received 450 mg I (group B), whereas all other patients received 300 mg I (group A). The enhancement of vessels was subjectively estimated using a four-point scale, and attenuation values were measured at predetermined levels. Multiple regression analyses were performed with attenuation as the dependent variable and patient age, sex, and weight; amount of contrast medium; scanning delay; and presence of embolism as the independent variables. The scanning delay for CT pulmonary angiography ranged from 10 to 31 seconds (mean, 19 seconds; SD, 3.3). Subjective estimates of enhancement quality on CT venography were significantly better for group B than for group A (p < 0.001). Multiple regression analyses revealed that body weight and age were the only significant and consistent independent variables associated with enhancement of the pulmonary arteries. The amount of contrast medium, body weight, and scanning delay were the independent variables that were consistently associated with enhancement of the deep veins. The bolus-tracking technique showed relatively small variations in the scanning delay time. Patient age, body weight, and the amount of contrast medium were the important factors associated with vessel enhancement in combined CT pulmonary angiography and CT venography.

Multidetector-row Computed Tomographic Angiography of Thoracic and Abdominal Aortic Aneurysms

To compare the quality of multidetector-row computed tomographic angiography in patients with and without aortic aneurysms by 3 different amounts of contrast media (CM). A total of 115 patients with aortic aneurysms were divided into 3 groups: group A, 100 mL CM; group B, 75 mL CM with 20 mL saline flush (SF); and group C, 50 mL CM with 20 mL SF. Twenty-five patients without aortic aneurysms were also enrolled (group D, 50 mL CM with 20 mL SF). Quantitative and qualitative analyses were performed by measuring attenuation in thoracoabdominal/aortoiliac lumen, aneurysmal lumen, and superior vena cava. In group C, attenuation was lower in distal than those in proximal and middle areas (P < 0.05). Contrast enhancement in abdominal aneurysmal lumen was more inhomogeneous in group C (P = 0.003). Visual analysis showed contrast enhancement was more nonuniform in group C (P = 0.004), and perivenous artifacts were more conspicuous in group A (P < 0.0001). Seventy-five milliliters CM followed by 20 mL SF can produce optimal contrast enhancement at systemic multidetector-row computed tomographic angiography in patients with aortic aneurysms.

Endoscopic palliation of unresectable hilar-cancer

Background: Hilar cholangiocarcinoma is a relatively infrequent malignancy. Unfortunately, less than 30% of these tumors are resectable due to both, the stage of the cancer or the advanced age and comorbidities of the patients. Jaundice, cholestasis, and pain are frequent clinical features present in hilar-cancer. In patients with unresectable tumor, palliative measures as endoscopic and/or percutaneous biliary stent placement are indicated for reduction of cholestasis. However, ERCP and endoscopic stent placement across hilar strictures harbors more chance of complications, most importantly infection. Our aim was to provide a summary of published endoscopic research related to this issue and present our experiences on the endoscopic palliation of hilar- cancer. Results: Our retrospective study showed that using self-expanding metallic stents (SEMS), the survival time significantly increased [median: 2 months (0.25–48)], but he rate of septic complications were not reduced (40%), as compared to the group of patients where plastic stents were placed. The presence of sepsis proved to be an independent predictor of decreased survival. The Bismuth stage, the gender, age of the patients and the severity of initial cholestasis were not predictors of survival. The patency of SEMS were significantly longer as compared to that of plastic stents (1.1 vs. 3.1 months). Conclusions: Based on our experience and the data of the literature the following conclusions can be drawn: 1. SEMS should be used instead of plastic stents.2. Stent may be placed unilaterally and positioned distally into the most easily accessible intrahepatic duct. 3. The smallest necessary amount of contrast media should be used. 4. It is also important that contrast media should be injected only in intrehepatic segments, which will be possible to subsequently drain.

Erfolgs- und Komplikationsrate der Coil-Embolisation arteriovenöser Fisteln nach Vena-saphena-magna-in-situ-Bypassanlage

To determine the success and complication rate of coil embolization of arteriovenous fistulae on in situ saphenous vein bypasses. 82 AV-fistulae on 30 bypasses (28 patients, 20 men, age 62.5 +/- 8.3 years) were treated using coils. The success rate, complications, duration, amount of contrast material and radiation exposure were measured. Color-coded duplex sonography was performed 1 - 2 days and up to 6 - 18 months after embolization. The success rate was 68.3 %. The reasons for persistent fistula perfusion were: 96 % fistula not accessible, 4 % reperfusion during thrombolysis. 7 complications were observed in 6 bypasses: failure of placement and retrieving of coil (n = 4), thrombembolic complications with thrombolysis (n = 3). The duration of intervention was 118.3 +/- 46.6 min, the contrast material need was 277.03 +/- 94.0 ml, and the radiation exposure was 10 966 +/- 11 295 cGy/cm (2). Additional balloon dilatation was performed in 30 % of the bypasses. All bypasses were open 1-2 days after intervention. During follow-up, 11 persistent fistulae were detected. Coil-embolization of arteriovenous fistulae on saphena magna bypasses proved to be a method with moderate success and complication rates.

Duplex-Assisted Internal Carotid Artery Balloon Angioplasty and Stent Placement

Carotid artery balloon angioplasty and stenting (CBAS) is gaining popularity as an adequate alternative to carotid endarterectomy (CEA) in selected patients. Unfortunately, the substantial amount of contrast media used for CBAS, traditionally performed under fluoroscopic guidance, may impair renal function in patients with diabetes or ones with elevated serum creatinine. We attempted to apply duplex assistance to limit or eliminate the use of contrast during CBAS. Fluoroscopy was utilized to assist manipulation of the guidewire into the aorta and the common carotid artery, and positioning of the distal cerebral protection device. Selective catheterization of the internal and external carotid arteries was performed under ultrasound guidance. Balloons and stent were successfully deployed with ultrasound guidance alone in all cases. Appropriate stent apposition and arterial patency were confirmed by duplex in all cases. One ipsilateral stroke (2.9%) occurred intraoperatively with almost complete clinical recovery in 4 months. On-table biplanar cerebral arteriogram performed in this patient was normal. No early (30-day) mortalities were in the series. Duplex-assisted CBAS is feasible and may reduce the need for contrast media in selected patients with high risk for renal failure. Additional advantages include guidance of the femoral puncture, precise position of the balloon and stent and B-mode and hemodynamic confirmation of the adequacy of the technique.