Evaluation of a noise reduction imaging technology in iliac digital subtraction angiography: noninferior clinical image quality with lower patient and scatter dose.

PURPOSE: To determine whether equivalent-quality images can be obtained from digital subtraction angiography (DSA) of the iliac artery after implementation of a novel imaging technology that reduces patient and scatter x-ray dose. MATERIALS AND METHODS: Imaging using two randomly ordered DSA runs was performed in 51 adults scheduled for iliac artery angiography or intervention or both. One DSA run used standard acquisition chain and image processing algorithms (referred to as " reference DSA"), and the other DSA run used dose-reduction and real-time advanced image noise reduction technology (referred to as "study DSA"). The quality of each pair of runs, consecutively performed without changes in working projection or injection parameters, was independently rated by five radiologists blinded to the imaging technology used. Patient radiation dose was evaluated using air kerma and dose area product, and scatter dose was evaluated using three dosimeters (DoseAware, Philips Healthcare, Best, The Netherlands), located at fixed positions. RESULTS: Comparable image pairs were available in 48 patients. There were 44 patients undergoing treatment involving the common (n = 33) or external (n = 29) iliac arteries. Study DSA images were rated as equal to or better than reference DSA images for 96% of comparisons, with an average overall agreement among raters of 0.93 (95% confidence interval, 0.65-0.96). Mean patient radiation dose (n = 48) and scatter dose rate for the three dosimeters (n = 50) was 83% ± 5 and 69% ± 10 lower, respectively, using the study technology (P < .001). CONCLUSIONS: Iliac artery DSA performed using a dose-reduction and real-time advanced image noise reduction technology results in image quality that is noninferior to conventional DSA but with significantly lower patient and scatter radiation exposure (P < .001).

MISAGO 2: one-year outcomes after implantation of the Misago self-expanding nitinol stent in the superficial femoral and popliteal arteries of 744 patients.

PURPOSE: To evaluate the safety and efficacy of the Misago self-expanding rapid-exchange nitinol stent system for the treatment of femoropopliteal occlusive disease in a prospective multicenter observational trial (ClinicalTrials.gov; identifier NCT01118117). METHODS: Between April and October 2008, the registry enrolled 744 patients (496 men; 69 ± 10 years) who had symptomatic ≥ 70% stenosis or occlusion of the superficial femoral or popliteal arteries treated with the Misago stent. Mean length of the 750 lesions was 63.9 mm; 282 (37.6%) vessels were completely occluded. Primary study endpoints were the need for target lesion revascularization (TLR) and event-free survival rates for the assessment of efficacy and safety, respectively. At 6 and 12 months post intervention, clinical symptoms of recurrent ischemia and/or claudication, Rutherford category, and ankle-brachial index (ABI) at rest were assessed. RESULTS: In the study period, 945 stents were successfully deployed in the 750 lesions. The overall TLR rate was 10.1% among 671 (90.3%) patients evaluated at 1 year [3.1% among 709 (95.3%) patients at 6 months]. Event-free survival at 12 months was 84.9%. Mean ABIs improved by ≥ 0.1 in three quarters of the patients (76.0%) over 12 months. The Rutherford grade improved or remained stable in the majority of patients (95.5%) after 1 year. Stent fractures (13 grade 1, 2 grade 2) in 3.1% of stents examined radiographically (n=484) at 1 year were not related to any clinical events. Primary patency was recorded in 574 (87.6%) patients evaluated at 1 year post procedure. CONCLUSION: The Misago rapid-exchange nitinol stent showed promising efficacy and safety results, with a low stent fracture rate, in patients with femoropopliteal disease, making it a safe and reliable treatment option.

Image quality of digital direct flat-panel mammography versus an analog screen-film technique using a phantom model.

OBJECTIVE: The objective of our study was to compare the detection and distinguishability of microcalcifications on mammograms obtained with a digital direct flat-panel detector versus an analog system using an anthropomorphic breast phantom. MATERIALS AND METHODS: Studies were performed with a digital mammography system (Selenia) and an analog mammography system (Mammomat 3). Sixty-five transparent films were used as test specimens. Randomly distributed round and heterogeneous silicate particles (diameter, 100-1,400 microm) and an anthropomorphic scatter body were applied to the films. All radiographs were taken at identical settings and exposures. Six radiologists rated the films and monitor-displayed images independently of each other in random order on a standardized electronic questionnaire. RESULTS: Interpretations based on monitor reading produced superior results over those based on digital image reading and analog film reading. In 41.1% (95% CI, 38.7-43.5%) of all the monitor readings, 20.2% (18.2-22.2%) of all digital images, and 19.6% (17.6-21.6%) of all analog films, the number of detectable microcalcifications agreed with the gold standard method. The diameter of visible microcalcifications was interpreted correctly in 35.6% (33.2-38.0%) of monitor readings, 19.0% (17.1-21.0%) of digital images, and 21.0% (18.9-23.0%) of analog films; and microcalcification shape was interpreted correctly in 53.8% (51.4-56.3%) of monitor readings, 28.2% (26.0-30.4%) of digital images, and 28.3% (26.0-30.5%) of analog films. Microcalcification number and size were underestimated more frequently than overestimated. Regardless of display medium, accuracy increased proportionately with the diameter of the simulated microcalcifications for all evaluation variables. CONCLUSION: Digital flat-panel mammography is superior to the analog screen-film method for the detection and morphologic characterization of microcalcifications larger than 200 microm in diameter when the display medium is a monitor.

The human error: delayed diagnosis of intravascular loss of guidewires for central venous catheterization.

We report three recent cases in which there was intravascular loss of the entire guide wire. In one case, this loss was discovered more than three months after the patient's procedure. In another case, the loss was detected one month later, and in the third case, four days was the interval of the loss. We discuss the problems of human error and failure of diagnosis, both of which were responsible for serious sequelae.

Sirolimus-eluting versus bare-metal low-profile stent for renal artery treatment (GREAT Trial): angiographic follow-up after 6 months and clinical outcome up to 2 years.

PURPOSE: To evaluate the patency of sirolimus-eluting stents (SES) compared to bare-metal stents (BMS) in the treatment of atherosclerotic renal artery stenosis (RAS). METHODS: Between November 2001 to June 2003, 105 consecutive symptomatic patients (53 men; mean age 65.7 years) with RAS were treated with either a bare-metal (n=52) or a drug-eluting (n=53) low-profile Palmaz-Genesis peripheral stent at 11 centers in a prospective nonrandomized trial. The primary endpoint was the angiographic result at 6 months measured with quantitative vessel analysis by an independent core laboratory. Secondary endpoints were technical and procedural success, clinical patency [no target lesion revascularization (TLR)], blood pressure and antihypertensive drug use, worsening of renal function, and no major adverse events at 1, 6, 12, and 24 months. RESULTS: At 6 months, the overall in-stent diameter stenosis for BMS was 23.9%+/-22.9% versus 18.7%+/-15.6% for SES (p=0.39). The binary restenosis rate was 6.7% for SES versus 14.6% for the BMS (p=0.30). After 6 months and 1 year, TLR rate was 7.7% and 11.5%, respectively, in the BMS group versus 1.9% at both time points in the SES group (p=0.21). This rate remained stable up to the 2-year follow-up but did not reach significance due to the small sample. Even as early as 6 months, both types of stents significantly improved blood pressure and reduced antihypertensive medication compared to baseline (p<0.01). After 6 months, renal function worsened in 4.6% of the BMS patients and in 6.9% of the SES group. The rate of major adverse events was 23.7% for the BMS group and 26.8% for the SES at 2 years (p=0.80). CONCLUSION: The angiographic outcome at 6 months did not show a significant difference between BMS and SES. Renal artery stenting with both stents significantly improved blood pressure. Future studies with a larger patient population and longer angiographic follow-up are warranted to determine if there is a significant benefit of drug-eluting stents in treating ostial renal artery stenosis.

Percutaneous embolization for cervicofacial neoplasms and hemorrhages.

OBJECTIVE: To retrospectively assess the effectiveness of percutaneous embolization for curative, preoperative or palliative management of hypervascular neoplasms, vascular malformations and bleedings of the head and neck area. METHODS: A retrospective 8-year analysis of outcomes in 85 patients undergoing preoperative embolization for tumors or vascular lesions of the head and neck or embolization for refractory tumor bleeding and epistaxis at our hospitals was performed by reviewing case records. Outcome of the preoperatively embolized patients was defined as successful if intraoperative bleeding was <500 ml and/or postinterventional angiogram showed complete occlusion of all tumor-feeding or bleeding vessels. RESULTS: Complete preoperative tumor embolization was achieved in 83.5% of the patients. Partial embolization was possible in 10.5%. All tumor bleedings refractory to conservative therapy and bleedings from epistaxis showed a successful outcome. CONCLUSIONS: In vascular lesions and tumors of the head and neck, preoperative percutaneous embolization improved the surgical outcome, reduced intraoperative blood loss significantly and facilitated tumor resectability. Cervicofacial bleeding resulting from a tumor, vascular malformation or epistaxis can be managed effectively by endovascular techniques.

Low-profile stent system for treatment of atherosclerotic renal artery stenosis: the GREAT trial.

PURPOSE: The Palmaz Genesis Peripheral Stainless Steel Balloon Expandable Stent in Renal Artery Treatment (GREAT) Trial was designed to assess the safety and performance of a low-profile stent for the treatment of obstructive renal artery disease by looking at 6-month renal artery patency uniformly analyzed by a Core Lab. MATERIALS AND METHODS: Fifty-two consecutive patients (mean age, 63.7 years) were successfully treated with the Palmaz Genesis Peripheral Stent (Cordis, Miami, FL) on the Slalom 0.018-inch Delivery System (Cordis Europe N.V., Oosteinde 8, NLO-9301 LJ Roden, The Netherlands) at 11 investigational centers. Patients with severe renal failure and > 8-mm renal artery were excluded. Primary endpoint was angiographic determination of in-stent percent diameter stenosis at 6 months. Fifty-one patients were treated with one stent, one patient was treated with two stents to cover the complete lesion. RESULTS: Mean percentage diameter stenosis before renal angioplasty was 68.2% +/- 12.0%. No stent implantation failure, displacement, need for additional stent implantation, or procedural complication was observed. Six-month angiography was performed in 41 of 52 patients (79%) resulting in a mean in-stent percent diameter stenosis or Quantitative Vessel analysis (QVA) at 6 months of 23.9%. The in-stent binary (percent diameter stenosis > 50%) restenosis rate at 6 months was 14.3%. No fatal events occurred up to 6 months after implantation. Major adverse events occurred in five patients: four patients (7.7%) required a revascularization and one patient (1.9%) experienced a cerebrovascular event, which regressed spontaneously. CONCLUSIONS: The Palmaz Genesis stent (Cordis) provides good results for renal artery stent placement, with an in-stent binary restenosis rate (percent diameter stenosis > 50%) at 6 months of 14.3% as determined with angiography.

Femoral pseudoaneurysms: management with percutaneous thrombin injections--success rates and effects on systemic coagulation.

PURPOSE: To determine the success rate of percutaneous ultrasonographically (US) guided thrombin injection in the treatment of femoral pseudoaneurysms and to evaluate the effects of thrombin injection on systemic coagulation parameters. MATERIALS AND METHODS: Fifty femoral pseudoaneurysms (37 simple pseudoaneurysms with one lobe and 13 complex pseudoaneurysms with two or three lobes) were treated with US-guided percutaneous thrombin injections. Pseudoaneurysm size, neck length and width, thrombin dose, outcome of therapy, and complications were documented prospectively. Duplex sonographic follow-up examinations were performed at 12-24 hours and 5-7 and 21-25 days. In 25 patients, activated thromboplastin time, Quick test (prothrombin time), thrombin time, fibrinogen, D-dimer, antithrombin III, thrombin-antithrombin III complex, and prothrombin fragments 1 and 2 were determined before and at 2, 5, and 10 minutes after thrombin injection. Differences in results before and those after thrombin injection were evaluated by means of the one-sample t test. RESULTS: Mean volume of pseudoaneurysms was 5.84 cm(3) +/- 4.89 (SD). Fifty-eight thrombin injections were performed. Mean thrombin dose was 357 IU +/- 291 in simple and 638 IU +/- 549 in complex pseudoaneurysms. Primary success rate was 36 of 37 (97%) for simple and eight of 13 (61%) for complex pseudoaneurysms. Reperfusion occurred in four complex pseudoaneurysms (none in simple ones). Secondary success rate was 100%. No thromboembolic, infectious, or allergic complications occurred. During follow-up, reperfusion was detected in one patient with a complex pseudoaneurysm. Levels of thrombin-antithrombin III complex increased significantly (P <.05) after thrombin injection, whereas changes in all other laboratory tests were not significant. CONCLUSION: US-guided percutaneous injection of thrombin is successful and safe in the management of femoral pseudoaneurysms. The increase of thrombin-antithrombin III complex indicates the possibility of thrombin passage into the arterial circulation.