Gadolinium contrast agents: their role in vascular and nonvascular diagnostic angiography and interventions.

Gadolinium-based contrast agents can be used for diagnostic and interventional angiographic procedures to reduce contrast-related nephrotoxicity or in patients with a history of severe allergic reaction to iodine-containing contrast material. These agents are best used in conjunction with CO(2) to complete nondiagnostic CO(2) angiograms and to monitor the progress of a percutaneous intervention. However, the total volume of gadolinium that can be administered, the reduced quality of gadolinium digital subtraction angiography images, and the increased cost of the gadolinium-based agents can limit their use.

Feasibility of gadodiamide compared with dilute iodinated contrast material for imaging of the abdominal aorta and renal arteries.

PURPOSE: To determine the quality of digital abdominal angiograms obtained with use of full-strength, intra-arterial gadodiamide compared with similar volumes of half-strength iodinated contrast material for evaluating the abdominal aorta and renal vessels. MATERIALS AND METHODS: Twenty-five consecutive patients underwent digital subtraction arteriography of the abdominal aorta performed with equal volumes (32 mL) of either half-strength (300 mg/mL iodine) iodinated contrast material or full strength gadodiamide (0.11-0.25 mmol/kg) to evaluate the abdominal aorta and renal arteries. The contrast agent used was not known to the image readers. The abdominal aorta, left and right renal main renal artery, and first and second order segmental branches were graded separately as diagnostic or nondiagnostic by four angiographers. RESULTS: Images of the abdominal aorta were diagnostic 100% of the time for iodine and gadodiamide, 76% and 80% diagnostic for iodine and gadodiamide in the left main renal artery, respectively; and 100% and 80% diagnostic for iodine and gadodiamide in the right main renal artery, respectively. The first order segmental branches of the right and left renal arteries were graded diagnostic 72% and 56% of the time, respectively, for dilute iodinated contrast material, and 40% and 28% of the time, respectively, for gadodiamide. The second order segmental branches of the right and left kidney were graded diagnostic 24% of the time for iodinated contrast and 8% and 4% of the time, respectively, for gadodiamide. CONCLUSION: Full-strength, intra-arterial gadodiamide at doses smaller than 0.3 mmol/kg can produce diagnostic images of the abdominal aorta and main renal arteries. However, images of the intrarenal branches are usually not diagnostic.

Lower extremity arteriography with use of iodinated contrast material or gadodiamide to supplement CO2 angiography in patients with renal insufficiency.

PURPOSE: To determine if the use of nonionic contrast material, as compared to the use of gadodiamide to supplement carbon dioxide angiography in patients with peripheral vascular disease (PVD) and chronic renal insufficiency (CRI), results in significant worsening of renal function. MATERIALS AND METHODS: Lower extremity angiographic procedures (diagnostic and diagnostic/intervention) were performed in 40 patients with CRI (baseline serum creatinine [Cr] > 1.5 mg/dL) using CO2 alone or CO2 supplemented with the use of either nonionic contrast material or gadodiamide (up to 0.4 mmol/kg). Serum creatinine levels were obtained before the procedure and at 48 hours after the procedure. The peak Cr level was also determined for patients with a significant (> 0.5 mg/dL) Cr elevation. RESULTS: Forty-two lower extremity angiographic procedures (19 diagnostic and 23 diagnostic/interventions) were performed in 40 consecutive patients from August 1997 to October 1998, with a mean preprocedure Cr of 2.2 mg/dL and a mean postprocedure Cr of 2.4 mg/dL. Twenty-five of the 40 patients (63%) had diabetes mellitus. Fifteen procedures, including six interventions, were performed utilizing CO2 and nonionic contrast material in 15 patients. Six of these 15 patients (40%) demonstrated a Cr increase > 0.5 mg/dL at 48 hours. Seven procedures, including two interventions, were performed with CO2 alone in seven patients. No patients in this group demonstrated an increase in serum creatinine of greater than 0.5 mg/dL at 48 hours. Twenty procedures, including 15 interventions, were performed with CO2 and gadodiamide in 18 patients. In one of these 20 procedures (5%) there was an increase in Cr > 0.5 mg/dL at 48 hours The difference in worsening renal function for the nonionic contrast group (six of 15) compared with the CO2/gadodiamide group (one of 20) was statistically significant (P = .03). When comparing the use of CO2 and nonionic contrast material versus CO2 alone and with gadodiamide (six of 15 versus one of 27), the difference is also statistically significant (P < .01). The average volume of supplemental contrast material was similar in the nonionic contrast material and gadodiamide groups, as was the average volume of supplemental nonionic contrast material in the six patients with an increased Cr. CONCLUSION: The use of small volumes of nonionic contrast material to supplement CO2 angiography in patients with PVD and CRI can be associated with a significant increased risk of worsening renal function when compared to angiography performed with CO2 alone or CO2 and gadodiamide.

Interventional uroradiologic procedures performed using gadodiamide as an alternative to iodinated contrast material.

Three patients with either a history of severe allergic reactions to iodinated contrast or marked renal insufficiency underwent interventional uroradiologic procedures using full-strength gadodiamide (Gd) as a contrast agent in place of iodinated contrast material. The procedures were percutaneous access for nephrostolithotomy, antegrade pyelography with placement of a nephroureteral stent, and a diagnostic nephrostogram with exchange of a nephroureteral stent. Gd was visualized fluoroscopically and produced satisfactory digital radiographs without allergic reaction or worsening renal function. Gd can be useful in guiding interventional uroradiologic procedures when iodinated contrast material is contraindicated.

Flow characteristics of peripherally inserted central catheters.

PURPOSE: Clinical applications of peripherally inserted central catheters (PICCs) are limited by the relatively small lumina and long lengths of these devices. Quantitative analysis of the flow capabilities of a variety of PICCs was performed to aid in deciding which patients should have a PICC and in selecting the appropriate catheter. MATERIALS AND METHODS: Sixteen different PICCs from six manufacturers were infused at flow rates of 25-270 mL/h. Infusions were performed with distilled water, normal saline, total parenteral nutrition solution, intralipids, and blood. Flow versus pressure curves were generated for each PICC and infusate. Additional catheter data recorded included the working length, outer diameter (OD), and inner diameter (ID) of the PICCs. RESULTS: Because of the thin wall construction of polyurethane catheters, PICCs made from polyurethane showed much better flow rates than silicone PICCs of a comparable OD. The measured ODs of the PICCs were 4-6 F, whereas the IDs ranged from 0.012 to 0.032 inch. Because of the small ID of some PICCs, infusing blood or intralipids is not practical. CONCLUSION: There is significant variability in the flow capabilities of available PICCs. Many of the PICCs require pressures greater than those that can be generated by commercially available infusion pumps. Matching PICC characteristics to the desired application will avoid many of the clinical problems currently encountered with PICCs.

Reducing the discomfort of lidocaine administration through pH buffering.

PURPOSE: A prospective, double-blind study was undertaken to evaluate the effect of using a buffered lidocaine solution on the perception of pain experienced by a patient during its intradermal injection. PATIENTS AND METHODS: One hundred fifty patients undergoing diagnostic angiographic and interventional procedures at the authors' institution were randomly assigned to receive a 1-mL aliquot of one of three lidocaine solutions: plain 1% lidocaine, 1% lidocaine diluted with normal saline in a 10:1 ratio, and 1% lidocaine diluted with 8.4% sodium bicarbonate in a 10:1 ratio. The lidocaine solutions were administered intradermally over 10-15 seconds. A numerical value was placed on the patient's perception of pain, separate from that associated with the 25-gauge needle insertion, with use of a linear visual analog scale. RESULTS: Mean pain scores were as follows: for the 1% lidocaine solution, 2.83 +/- 2.60; for 1% lidocaine plus normal saline solution, 2.89 +/- 2.34; and for 1% lidocaine plus sodium bicarbonate solution, 1.37 +/- 1.73 (P = .0018). CONCLUSION: Buffering lidocaine significantly decreased the discomfort associated with its administration as a local anesthetic.

Balloon angioplasty above the aortic arch: immediate and long-term results.

OBJECTIVE: Angioplasty above the level of the aortic arch is becoming more common, and the indications for it are increasing. We report our experience with this procedure, including life-table analysis of the long-term results. MATERIALS AND METHODS: We dilated 32 lesions in 29 patients. Early in our series, patients were referred primarily because of arm claudication or vertebrobasilar insufficiency. Subsequently, the indications were expanded to include inflow to left internal mammary-coronary artery bypass grafts, inflow to axillobifemoral bypass grafts, and inflow to dialysis fistulas in the upper extremity. A femoral artery approach was used in 18 patients and an axillary approach was used in 11. Clinical follow-up included evaluation of symptoms and bilateral measurements of peripheral pulses and blood pressure. Follow-up angiograms were obtained in nine patients. RESULTS: Eighteen of the lesions dilated were located in the left subclavian artery, eight were in the right subclavian artery, four were in the axillary or proximal brachial artery, and two were in the innominate artery. Interestingly, three of eight right subclavian arteries treated had an anomalous origin from the arch of the aorta. Initial technical success was 100%. All 29 patients had long-term follow-up of 4-88 months (mean, 36 months). In one patient, stenosis recurred 8 months after angioplasty. This patient subsequently had redilatation. Life-table analysis projected a 7.5-year cumulative primary patency rate of 96.6%. No cerebrovascular complications or embolic events occurred. CONCLUSION: Angioplasty of the great vessels is safe and effective, and the long-term results are favorable when compared with results after surgery. As a result, the indications for this procedure should be broadened.

Results and complications of angioplasty in fibromuscular disease.

Percutaneous transluminal angioplasty (PTA) was used to treat 66 patients with 85 renal artery stenoses due to fibromuscular dysplasia. The hypertension was refractory to medical management in 46 patients, and the initial success rate was 100%. Clinical follow-up has been obtained in all patients, who were followed for as long as 121 months. The recurrence rates were 8% of lesions and 10% of patients. Cumulative patency rate predicted for 10 years was 87.07%. The mean systolic pressure decreased by 52 mm Hg and the mean diastolic pressure decreased by 35 mm Hg in response to treatment. Twenty-six patients (39%) were cured, 39 (59%) were classified as improved, and one (2%) did not respond to PTA. Fourteen of the patients also had elevated blood urea nitrogen and creatinine levels. Renal function was improved in 86% of the patients and stabilized in 14% of the patients. Analysis of the long-term results suggests that PTA should be the initial treatment for choice of patients with fibromuscular dysplasia in the renal arteries.

Results and complications of angioplasty in aortoiliac disease.

Percutaneous transluminal angioplasty was used to treat 340 aortoiliac lesions in 200 patients who were followed for as long as 90 months (mean, 28.7 months; median, 23 months). The initial success rate was 94.7% for lesions and 93.0% for patients. The indications for percutaneous transluminal angioplasty included claudication in 117 patients (58.5%), rest pain or ischemic night pain in 47 (23.5%), limb salvage in 33 (16.5%), and aiding in wound healing in three (1.5%). In the series, 70% of the patients had two or more cardiovascular risk factors. Angioplasty was initially unsuccessful in 14 patients, and 10 patients were lost to follow-up. Follow-up was obtained in 176 patients. The long-term results were analyzed using the life table method to determine cumulative patency. Fourteen patients were considered failures because of recurrent disease or symptoms. The projected 7.5-year cumulative patency rate was 85%. When the response to redilatation was considered, the projected 7.5-year cumulative patency rate was 92%. The results indicate that percutaneous transluminal angioplasty can successfully correct aortoiliac lesions and provide a long-term benefit for as long as 7.5 years.

Development and implementation of a quality assurance program for mammography.

As a pilot study for a national campaign to promote the use of screening mammography, the Virginia Division of the American Cancer Society conducted a breast cancer awareness project with mammography screening. An important part of the program was the development of a quality assurance program for mammography. Guidelines were established for equipment, image recorders, processing, dose, and patient positioning. A survey of information about the mammographic equipment was conducted, and the mammograms from each facility were reviewed. A total of 63 mammographic units in 56 facilities statewide were included in the month-long program during which approximately 9,000 women were screened.