Inferior pancreaticoduodenal artery aneurysms in association with celiac axis stenosis or occlusion.

PURPOSE: To describe the pathophysiology, identification and management of inferior pancreaticoduodenal artery aneurysms in association with celiac axis stenosis or occlusion has been reported. REVIEW FINDINGS: These aneurysms are thought to arise due to increased flow through the pancreaticoduodenal arcades. The arcades first enlarge, and then form focal aneurysms which may rupture. The aneurysms can be treated through endovascular techniques or by surgery, though the former is a preferred approach.

Endovascular stent-graft in abdominal aortic aneurysms: the relationship between patent vessels that arise from the aneurysmal sac and early endoleak.

PURPOSE: To determine the association of patent sac branch vessels (lumbar and inferior mesenteric arteries [IMAs]) with early endoleak rate after stent-graft repair of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: Pre- and postoperative computed tomographic (CT) angiograms in 158 patients who underwent stent-graft AAA repair were retrospectively reviewed to determine the preoperative patency of IMAs and other sac branch vessels (feeders) and presence or absence of immediate postoperative endoleak. Relationships of early endoleak rate with total branch vessel, IMA, and lumbar artery patency and graft type were evaluated. RESULTS: There was a significant association between patency of sac feeders and rate of early endoleak, especially type 2. As total patent feeders increased from zero to three to four to six, total endoleak rate increased from 6% (one of 17) to 35% (30 of 86); type 2 endoleak rate, from 0% to 25%. IMA patency was significantly associated with total early endoleak rate. Increasing lumbar artery patency also was associated with significantly higher total and type 2 endoleak rates: With zero to three lumbar arteries, the total endoleak rate was 17% and type 2 endoleak rate was 13%, as compared with 60% and 50%, respectively, with more than six patent lumbar arteries. CONCLUSION: Sac branch vessel patency is associated with significantly higher early total and type 2 endoleak rates after stent-graft repair of AAAs; thus, patent sac branches play an important role in the pathogenesis of endoleaks.

Inferior vena caval filters: review of a 26-year single-center clinical experience.

PURPOSE: To review a 26-year single-center clinical experience with inferior vena caval filters. MATERIALS AND METHODS: During 1973-1998, 1,765 filters were implanted in 1,731 patients. Hospital files were reviewed, and data were collected about the indications, safety, effectiveness, numbers, and types of caval filters. Fatal post-filter pulmonary embolism (PE) was considered the primary outcome. Morbidity and mortality were determined as secondary outcomes. Survival and morbidity-free survival curves were calculated. RESULTS: The prevalence of observed post-filter PE was 5.6%. It was fatal in 3.7% of patients. In most patients, fatal PE occurred soon after filter insertion (median, 4.0 days; 95% CI: 2.2, 5.8 days). Major complications occurred in 0.3% of procedures. The prevalence of observed post-filter caval thrombosis was 2.7%. The 30-day mortality rate was 17.0% overall, higher among patients with neoplasms (19.5%) as compared with those without neoplasms (14.3%; P =.004). Filter efficacy and associated morbidity were not different in 46 patients with suprarenal filters. The rate of filters placed for prophylaxis was 4.7% overall and increased to 16.4% in 1998. From 1980 to 1996, there was a fivefold increase in the number of caval filter implants. In recent years, more filters were implanted in younger patients. CONCLUSION: Inferior vena caval filters provide protection from life-threatening PE, with minimal morbidity.

Clinical outcome of internal iliac artery occlusions during endovascular treatment of aortoiliac aneurysmal diseases.

PURPOSE: To determine the clinical outcome of hypogastric artery occlusion in patients who underwent endovascular treatment of aortoiliac aneurysmal disease. MATERIAL AND METHODS: From January 1994 to March 1998, 94 patients underwent endovascular treatment of aneurysmal diseases involving the infra-abdominal aorta or iliac arteries. Preoperative and intraoperative radiologic data were reviewed. Discharge summaries, clinic visits, and phone calls formed the basis for clinical follow-up, with a mean follow-up period of 7.3 months (range, 1-24 months). RESULTS: Because of the anatomy of the aneurysms, 28 patients required occlusion of one or more hypogastric arteries. One of the 28 patients died of unrelated causes before follow-up. Seven (26%) of the remaining 27 patients developed symptoms attributable to the hypogastric artery occlusions. Five patients developed new buttock or thigh claudication; of these five patients, three with initially mild symptoms noted complete or near complete resolution of symptoms upon follow-up. One patient with originally significant claudication at 2-year follow-up noted near resolution of symptoms. The other patient with severe pain did not improve significantly on final 1-year follow-up before his death (of unrelated causes). Other clinical complications were worsening sexual function in one patient and a nonhealing sacral decubitus ulcer that developed in a debilitated patient in the postoperative setting, which required surgery. No bowel ischemia was observed. CONCLUSION: When treating aortoiliac aneurysmal disease through an endovascular approach, the occlusion of internal iliac artery is often necessary but carries with it a small but finite chance of morbidity.

Custom bifurcated stent-graft for abdominal aortic aneurysms: initial experience.

PURPOSE: To describe a custom bifurcated stent-graft for possible treatment of abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: Five male patients (mean age, 76 +/- 6 years), who had AAA (mean diameter, 4.7 +/- 0.4 cm) and who were considered to be at high risk for conventional surgery, were treated with a custom modular bifurcated stent-graft constructed with bifurcated 24-mm x 12-mm (upper body diameter x iliac limb diameter) Cooley Veri-Soft Woven polyester grafts and Gianturco-Rösch Z stents. The stent-graft body was delivered through 20-22-F sheaths, and the contralateral iliac limb was delivered through a 16-F sheath by means of surgical exposure of the common femoral arteries. A flared distal limb extender (12 mm to 14 mm) was created for one patient to accommodate a large common iliac artery. RESULTS: Stent-grafts were successfully deployed without complications in all five patients. There were no proximal or distal leaks. A lumbar-to-inferior mesenteric artery leak was seen in one patient at 24 hours. At 6-month follow-up, all devices were intact, with complete exclusion and shrinkage of the aneurysm in four of five patients. Aneurysm size remained stable in the one patient with a lumbar-to-inferior mesenteric artery leak. CONCLUSION: A custom, bifurcated stent-graft was utilized for endovascular treatment of AAA. Long-term follow-up is necessary for the device.

Gadolinium-based contrast agents as an alternative at vena cavography in patients with renal insufficiency--early experience.

The authors reviewed results of digital subtraction vena cavography with a gadolinium-based contrast agent in 14 patients with serum creatinine levels greater than or equal to 1.5 mg/dL (133 mumol/L). All cavograms were diagnostic. In 11 patients, there was no impairment of renal function. In three patients, a rise in serum creatinine level of greater than or equal to 0.5 mg/dL (44 mumol/L) was attributable to concurrent medical problems. Gadolinium-based contrast agents may be suitable for digital subtraction vena cavography in patients with renal insufficiency.

D-dimers in the diagnosis of pulmonary embolism.

The aim of this study was to determine if the absence of circulating D-dimers, as determined by latex agglutination assays, can correctly exclude the presence of pulmonary embolism using pulmonary angiography as the diagnostic endpoint. Blood samples were obtained prospectively at the time of angiography for suspicion of acute pulmonary embolism. Plasma was assayed for D-dimer by five different latex agglutination assays. Angiographic evidence of pulmonary emboli was found in 34% (35/ 103) of patients. The latex agglutination assays had sensitivities of 97 to 100% and specificities of 19 to 29%. The negative predictive value was 94 to 100%. However, a negative D-dimer was rare in patients with recent surgery, malignancy, or total bilirubin > 34 micromol/L (> 2 mg/dl). In 31 patients suspected of pulmonary emboli but without these confounding factors, the five D-dimer assays were negative in 46 to 55% of patients with normal pulmonary angiograms. The negative predictive value in these patients was 100% by all five latex agglutination assays tested. The latex agglutination assays for D-dimer, when the pulmonary angiogram is used as the diagnostic endpoint and in the absence of recent surgery, malignancy, or liver disease, appears to be a clinically useful test in the diagnosis of acute pulmonary embolism.

Cost comparison of radiologic versus surgical placement of long-term hemodialysis catheters.

OBJECTIVE: The purpose of this study was to compare the cost of radiologic versus surgical placement of long-term hemodialysis catheters. MATERIALS AND METHODS: Our cost analysis was based on 47 long-term hemodialysis catheters radiologically placed in 45 patients and 25 catheters surgically placed in 25 patients from October 1996 through March 1997. Variable and total costs were calculated using data from the hospital administrative computer system that records the actual costs incurred by the hospital in caring for patients. RESULTS: The average total hospital cost was $926 for each radiologic placement and $1849 for each surgical placement of long-term hemodialysis catheters. The total cost saving for radiologic placement was $923 for each catheter. CONCLUSION: Radiologic placement of long-term hemodialysis catheters resulted in substantial savings over surgical placement.

Gadopentetate dimeglumine: a possible alternative contrast agent for CT angiography of the aorta.

We report the use of a gadolinium chelate for limited CT angiography of the aorta in a patient in whom iodinated contrast agent was contraindicated and who had undergone nondiagnostic MRI.

Acute pulmonary embolism: assessment of helical CT for diagnosis.

PURPOSE: To determine the sensitivity and specificity of helical computed tomography (CT) for the diagnosis of acute pulmonary embolism. MATERIALS AND METHODS: This prospective study included 47 patients who underwent pulmonary arteriography for evaluation for possible acute pulmonary embolism. Tailored helical CT and pulmonary arteriography were performed within 24 hours of each other. Each CT scan was interpreted by two chest radiologists, blinded to arteriographic results, at two institutions. CT scan interpretations were compared with findings on bilateral selective pulmonary arteriograms interpreted by two vascular radiologists at one institution. RESULTS: Fifteen (32%) of 47 patients had angiographically proved pulmonary embolism. For the readers at the first institution, helical CT had 60% sensitivity, 81% specificity, 60% positive predictive value, 81% negative predictive value, and 75% overall accuracy. For the readers at the second institution, helical CT had 53% sensitivity, 97% specificity, 89% positive predictive value, 82% negative predictive value, and 83% accuracy. CONCLUSION: Detection of pulmonary embolism with helical CT may be less accurate than previously reported. Given its high specificity but relatively low sensitivity, helical CT may not have the ideal attributes of a first-line imaging study for the diagnosis of pulmonary embolism.

Evaluation of renal artery stenosis with dynamic gadolinium-enhanced MR angiography.

OBJECTIVE: The purpose of this study was to compare dynamic gadolinium-enhanced three-dimensional spoiled gradient-recalled MR angiography with conventional arteriography in the evaluation of proximal renal artery stenosis (RAS). MATERIALS AND METHODS: MR angiography and conventional arteriographic examinations of 30 patients evaluated for RAS were analyzed retrospectively. Three-dimensional MR angiography was performed with an RF spoiled gradient-recalled imaging sequence acquired during the dynamic i.v. injection of gadolinium (0.2-0.3 mmol/kg), MR data and conventional arteriograms were independently evaluated for the number and location of renal arteries and the degree and location of stenoses. The patients had a mean age of 70 years old and a mean serum creatinine level of 2.9 mg/dl, reflecting a population in whom atherosclerotic RAS was the primary concern. RESULTS: Gadolinium-enhanced MR angiography revealed 100% of main renal arteries. For RAS of 50% or greater occlusion, the technique was 100% sensitive and 71% specific; the negative predictive value was 100%. The technique was 100% sensitive and 71% specific for RAS of 75% or greater occlusion. CONCLUSION: Dynamic gadolinium-enhanced three-dimensional spoiled gradient-recalled MR angiography has a high sensitivity for revealing proximal RAS and is a quick and reliable technique for obtaining helpful anatomic information.

Migration of central venous catheters: implications for initial catheter tip positioning.

PURPOSE: To evaluate the change in position of chest wall central venous access catheters (CVACs) after placement. Complication rates associated with catheter tip position were reviewed. PATIENTS AND METHODS: Fifty patients (36 women, 14 men) with chest wall CVACs placed in the angiography suite were studied. Catheter migration was calculated as the difference between the carina-catheter tip measurements on immediate supine and upright postprocedure (within 24 hours) chest radiographs. Catheter-related complication data were gathered via telephone interview and review of the medical records. RESULTS: Peripheral catheter migration occurred in 49 of 50 patients (average, 3.2 cm +/- 1.8); central catheter migration occurred in one of 50 patients (3.9 cm). Catheter type was the only significant factor that affected the amount of migration; side of insertion or the patient's gender were not significant. Catheter malfunction and symptomatic upper extremity venous thrombosis rates tended to be lower in patients with right atrial versus superior vena cava catheters (18% vs 34%), but differences were not significant (P = .202). CONCLUSION: Catheter migration after chest wall CVAC placement is a common event. The catheter tip should be initially positioned approximately 3-4 cm more centrally than the desired final position. Further study is necessary of catheter-related complication rates relative to the final position of the catheter tip.

Evaluation of a new percutaneous stainless steel Greenfield filter.

PURPOSE: To evaluate a new percutaneous Greenfield filter with an alternating hook design and over-the-wire delivery system. MATERIALS AND METHODS: The alternating hook stainless steel Greenfield filter was evaluated in a prospective clinical trial between March 10, 1994, and January 27, 1995. Filters were placed in 75 patients in nine clinical centers and follow-up with radiographs and ultrasound scans was carried out at 30 days. RESULTS: Clinical trial results revealed successful placement in all patients. There were four cases of filter limb asymmetry (5.3%) without clinical sequelae, with one incidence of failure to span the cava. No significant migration was found. There were no clinically suspected pulmonary emboli, but one instance of probable caval penetration (1.7%) did occur. Caval occlusion was documented in three patients (5%). CONCLUSION: The percutaneous stainless steel Greenfield filter provides ease of insertion and improved deployment while maintaining the high standards of efficacy and safety associated with the standard and titanium Greenfield filters.