Carbon dioxide in angiography to reduce the risk of contrast-induced nephropathy.

In the 1970s, Hawkins pioneered the intra-arterial use of carbon dioxide gas for high-risk patients who were allergic to iodinated contrast material and for those with renal failure. With the advent of digital subtraction angiography in 1980, reliable imaging of "low-density" CO(2) contrast agent became available. Subsequently, with the addition of high-resolution of digital subtraction angiography, stacking software (adding multiple images), tilting tables and a reliable, user-friendly delivery system, CO(2) imaging has become nearly comparable to and, in some cases, superior to that of iodinated contrast media.

False-positive "Cavernous Transformation" secondary to lymphatic filling in parenchymal hepatic CO(2) injection for portal vein visualization in TIPS procedures.

Purpose: To determine the frequency and potential importance of findings initially interpreted as portal vein occlusion with "cavernous transformation" at transjugular intrahepatic portosystemic shunt (TIPS) placement with hepatic parenchymal CO(2) injection.

Materials And Methods: One hundred forty-seven patients underwent hepatic parenchymal CO(2) injections in the setting of fine-needle CO(2) TIPS procedures. Hepatic parenchymal CO(2) injections were retrospectively reviewed for findings suggestive of cavernous transformation in which direct portal venography confirmed portal vein patency.

Factors predicting survival after transjugular intrahepatic portosystemic shunt creation: 15 years' experience from a single tertiary medical center.

Purpose: This retrospective analysis was conducted to identify factors predictive of survival after transjugular intrahepatic portosystemic shunt (TIPS) creation.

Materials And Methods: Patients who underwent TIPS creation between January 1991 and December 2005 at a tertiary-care center were identified. Log-rank tests were used to compare the cumulative survival functions among groups of patients who underwent TIPS creation for various indications.

Potential air contamination during CO2 angiography using a hand-held syringe: theoretical considerations and gas chromatography.

Purpose: To assess air contamination in the hand-held syringes currently used for CO2 delivery and to determine whether there is an association between their position and the rate of air contamination.

Methods: Assessment of air contamination in the syringe (20 ml) included theoretical modeling, mathematical calculation, and gas chromatography (GC). The model was used with Fick's first law to calculate the diffusion of CO2 and the amount of air contamination.

A simple DSA method to detect air contamination during CO2 venous studies.

The use of CO2 as a contrast agent has increased significantly for visualization of the central veins, inferior vena cava, and portal vein. The most serious complication associated with CO2 studies is air contamination. We evaluated a simple digital subtraction angiogram (DSA) method to detect air contamination during CO2 venous studies.

Preoperative portal vein embolization for extended hepatectomy.

Objective: To examine the authors' experience with preoperative ipsilateral portal vein embolization (PVE) and assess its role in extended hepatectomy.

Summary Background Data: Extended hepatectomy (five or more liver segments) has been associated with higher complication rates and increased postoperative liver dysfunction than have standard hepatic resections involving lesser volumes. Recently, PVE has been used in patients who have a predicted (postresection) future liver remnant (FLR) volume less than 25% of total liver volume in an attempt to increase the FLR and reduce complications.

CO2 splenoportography: preliminary results.

Objective: Previously, splenoportography with 18-gauge needles provided excellent portal imaging. However, because of concern about bleeding, this technique was replaced with arterial portography and noninvasive techniques, which are not always accurate. We present a modification of splenoportography using CO2 and an ultrafine needle in eight patients whose previous imaging studies were inconclusive.

Hepatic artery embolization for control of symptoms, octreotide requirements, and tumor progression in metastatic carcinoid tumors.

Hepatic artery embolization (HAE) has been utilized for treatment of advanced hepatic carcinoid metastases, with promising symptom palliation and tumor control. Our institution employs transcatheter HAE using Lipiodol/Gelfoam for treatment of carcinoid hepatic metastases, and this report presents our experience with twenty-four patients, examining symptom control, quality-of-life, octreotide dependence, and tumor progression. Twenty-four (11 male, 13 female, mean age = 59.

Minimizing hemodialysis vascular access trauma with an improved needle design.

The maintenance and longevity of hemodialysis vascular access remains one of the most problematic topics in the care of dialysis patients. Although much attention has focused on neointimal hyperplasia, the repetitive trauma to vessel walls by dialysis needles causes significant cumulative damage that has undergone little investigation. Commercial needles have beveled tips with intentional cutting surfaces to ease insertion.