The cannon catheter--a prospective analysis.

Clinical outcomes associated with hemodialysis catheters often depend on correct tip positioning. Improper positioning of the catheter tips can reduce blood flow and lead to long-term complications. The authors evaluated the clinical performance of the Arrow Cannon II Plus hemodialysis catheter (Teleflex Medical, Research Triangle Park, North Carolina), a catheter that was designed for tip-first (retrograde) placement to ensure accurate central positioning in the right atrium for optimal flow and minimal recirculation. This 6-month prospective analysis found that the catheter provided high blood flow rates (maximum flow, 410.9-to 430.4 mL/min; mean flow, 378.9-402.4 mL/min) with recirculation rates well below the Kidney Disease Outcomes Quality Initiative (KDOQI) limit (3.6% to 0%). In summary, the Arrow Cannon II Plus hemodialysis catheter was associated with high blood flow rates and minimal complications. Tip-first placement of this novel device represents an important advancement in vascular access for high-performance hemodialysis.

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. Direct portography was performed by injecting CO(2) via the fine needle/guide wire complex or a 5-F catheter in a branch of the intrahepatic portal vein. RESULTS: Hepatic lymphatic vessels mimicked cavernous transformation of the portal vein in 29 of the 147 patients (19.7%). One patient with portal vein occlusion showed profuse lymphatic filling without filling the extrahepatic portal vein. Hepatic parenchymal CO(2) injections safely permitted targeting of the portal vein in all patients. CONCLUSIONS: During fine-needle CO(2) TIPS procedures, what was believed to represent reversed flow of hilar collateral vessels represented hepatic lymphatic vessels. Despite the lack of visualization of the portal vein in nearly one-fifth of patients, targeting of the portal vein was facilitated by the fact the hepatic lymphatic vessels showed a periportal distribution. The high incidence of hepatic lymphatic filling suggestive of cavernous transformation necessitates direct portography or wedged hepatic venography to verify portal vein patency before the procedure is aborted.

Technical success and safety of retrieval of the G2 filter in a prospective, multicenter study.

PURPOSE: To assess the technical success and safety for retrieval of the G2 filter. MATERIALS AND METHODS: The authors performed a prospective, multicenter study of 100 patients with temporary indication for caval interruption. Patients were enrolled consecutively between December 2005 and July 2006. There were 67 men and 33 women with a mean age of 52.1 years (range, 19-82 years). Indications for filter placement were trauma (n = 56), perioperative risk (n = 16), and medical indications (n = 28). Forty-two patients had venous thromboembolism at filter placement. Fifty-eight filters were placed prophylactically. RESULTS: Retrieval was attempted in 61 patients. Fifty-eight of the 61 filters (95%) were successfully retrieved after a mean dwell time of 140 days (range, 5-300 days). In all failed retrievals, the filter tip was against the caval wall. There was no difference in dwell times between successful and unsuccessful retrievals. Although there were no cases of cranial migration, caudal migrations were observed in 12% of cases (10 of 85 patients with a complete data set). Other device-related complications included filter fracture (1/85, 1.2%), filter tilt of more than 15 degrees (15/85, 18%), and leg penetration (16/61, 26%). The recurrent pulmonary embolism (PE) rate was 2%, with no PE in the 30-day period after filter retrieval. CONCLUSIONS: Retrieval of the Recovery G2 filter was safe and successful in most patients. Caudal migration was observed as an unexpected phenomenon.

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. Thirty-day mortality after TIPS creation was examined by logistic regression. Cox proportional-hazards analyses were performed to analyze the cumulative 90-day and 1-year survival. Selected variables such as creatinine, bilirubin, and International Normalized Ratio (INR) were assessed with respect to survival. RESULTS: The study included 352 patients, of whom 229 (65.1%) were male. The mean age at the time of TIPS creation was 53.6 years (range, 21-82 y). A Model for End-stage Liver Disease (MELD) score greater than 15 was significantly associated with poor survival (P < .05) at 30 days, 90 days, and 1 year after TIPS creation. Independently, a serum total bilirubin level greater than 2.5 mg/dL, an INR greater than 1.4 (P < .05), and a serum creatinine level greater than 1.2 mg/dL were predictive of poor survival. Finally, age greater than 70 years was associated with poor survival at 90 days and 1 year after TIPS creation (P < .05). CONCLUSION: The choice to create a TIPS in individuals whose MELD score is greater than 15 and/or whose age is greater than 70 years should involve a careful consideration of risk/benefit ratio, taking into account the finding that such patients have significantly poorer survival after TIPS creation.

Vascular Imaging with Carbon Dioxide: Confidence in a Safe, Efficacious, User-Friendly System.

Carbon dioxide (CO2) has been used as an imaging agent since the early 1900s. The intravascular use of CO2 for imaging began in the 1960s. Its use was limited, as the available technology for imaging and safe delivery was poor. Even until today its use as an imaging agent has not reached its potential because of non-user friendly and cumbersome delivery methods. Confusing tanks, valves, and assembly of do-it-yourself systems create an aversion to its use. As an invisible agent with properties vastly different from liquid contrast, well-seasoned interventionalists are hesitant to use it because of perceived often unrealistic potential complications. Despite many of the advantages of a gaseous imaging agent, insecurity has translated to its lack of use and availability to the benefit of patients. With the development of the new CO2mmander/AngiAssist delivery system (AngioAdvancements, Inc; Ft. Meyers, FL), a compact, unwieldy, easily understood, closed system that does not require assembly is replacing the various makeshift systems in the CO2 community. This system combines a small multiuse disposable cylinder, compact regulator, and a dual syringe delivery system to the patient. A unique proprietary valve (K-valve) prevents the possibility of CO2 overload during delivery. Because of one-way valves and the prepackaged complete setup, operator error and air contamination with inadvertent connections are eliminated. Noncompressed CO2 is administered in the volume of choice in a nonexplosive manner. This simple, yet safe and effective, delivery system will undoubtedly promote the greater use of intravascular CO2. This in turn will translate into improved patient care in both the diagnostic and interventional arena.

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 = 59.4 +/- 2.5 yr) patients with carcinoid and unresectable hepatic metastases, confirmed by urinary 5-hydroxyindole acetic acid (5-HIAA) measurement and biopsy, were treated with Lipiodol/Gelfoam HAE from 1993-2001. Median follow-up was 35.0 months. Before HAE, 14 patients (58.3%) had malignant carcinoid syndrome, with symptoms quantified using our previously reported Carcinoid Symptom Severity Score, and 13 patients (54.2%) required octreotide for symptom palliation. Following treatment, symptom severity, octreotide dose, and tumor response were measured. Asymptomatic patients did not develop symptoms or require following treatment. Hepatic metastases remained stable (n = 4) or decreased (n = 19) in 23 patients (95.8%). Mean pretreatment Symptom Severity Scores (3.8 +/- 0.2), decreased to 1.4 +/- 0.1 post-treatment (P < 0.00001), with 64.3% of patients becoming asymptomatic. Mean pretreatment octreotide dosages (679.6 +/- 73.0 microg/d), decreased to 262.9 +/- 92.7 microg/d (P = 0.0024) post-treatment, with 46.2% of patients discontinuing octreotide. There were no treatment-related serious complications or deaths. This study demonstrates that Lipiodol/Gelfoam HAE produces excellent control of malignant carcinoid syndrome, allowing patients to decrease or eliminate use of octreotide, while controlling hepatic tumor burden.

Impact of transarterial therapy in hepatitis C-related hepatocellular carcinoma on long-term outcomes after liver transplantation.

OBJECTIVES: To evaluate the impact of long-term outcomes of transarterial embolization (TAE) therapy in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) on the waiting list for liver transplantation (LT). METHODS: We retrospectively evaluated the post-LT patients with HCV-related HCC who received TAE intervention (n=33) and those who had no treatment (n=47) while on the waiting list to determine long-term outcomes. RESULTS: Over a 10-year period, of the 424 patients transplanted with HCV, 80 patients had HCC with a tumor burden within Milan criteria. For the entire study cohort, the mean duration of post-LT follow-up was 3.5 years; mean time of transplant waiting list was 120 days; and median post-LT survival was 8.9 years. The survival rates at 1, 3, 5, and 10 years were 82%, 70%, 55%, and 35%, respectively. From the study cohort, 33 patients received TAE and 47 patients did not while on the waiting list. The 2 groups were well matched, except, that the intervention patients received post-LT interferon more often and had a shorter time on the waiting list (56.2 d) when compared with the no treatment group (164.6 d, P<0.001). Median survival in the TAE group was 4.8 years and 8.9 years in the no treatment group. The recurrence rate was 15.6% in the treatment group and 6.9% in the no therapy group (P=0.275). CONCLUSIONS: Pre-LT transarterial therapy has no benefit on post-LT survival and tumor recurrence in patients with HCV-related HCC who underwent a mean waiting period of <3 months to transplant.

Transcatheter treatment of hepatocellular carcinoma with Doxorubicin-loaded DC Bead (DEBDOX): technical recommendations.

Tranarterial chemoembolization (TACE) has been established by a meta-analysis of randomized controlled trials as the standard of care for nonsurgical patients with large or multinodular noninvasive hepatocellular carcinoma (HCC) isolated to the liver and with preserved liver function. Although conventional TACE with administration of an anticancer-in-oil emulsion followed by embolic agents has been the most popular technique, the introduction of embolic drug-eluting beads has provided an alternative to lipiodol-based regimens. Experimental studies have shown that TACE with drug-eluting beads has a safe pharmacokinetic profile and results in effective tumor killing in animal models. Early clinical experiences have confirmed that drug-eluting beads provide a combined ischemic and cytotoxic effect locally with low systemic toxic exposure. Recently, the clinical value of a TACE protocol performed by using the embolic microsphere DC Bead loaded with doxorubicin (DEBDOX; drug-eluting bead doxorubicin) has been shown by randomized controlled trials. An important limitation of conventional TACE has been the inconsistency in the technique and the treatment schedules. This limitation has hampered the acceptance of TACE as a standard oncology treatment. Doxorubicin-loaded DC Bead provides levels of consistency and repeatability not available with conventional TACE and offers the opportunity to implement a standardized approach to HCC treatment. With this in mind, a panel of physicians took part in a consensus meeting held during the European Conference on Interventional Oncology in Florence, Italy, to develop a set of technical recommendations for the use of DEBDOX in HCC treatment. The conclusions of the expert panel are summarized.

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. It is the only safe contrast agent for patients in renal failure, which is extremely important in view of the increasing incidence of diabetes and complexities of interventional procedures. The low viscosity of CO(2) not only improves the sensitivities of several diagnostic procedures but may afford advantages for several interventional procedures.

Apparently nonspecific enzyme elevations after portal vein delivery of recombinant adeno-associated virus serotype 2 vector in hepatitis C virus-infected chimpanzees.

Hepatic gene transfer is envisioned as a substitute for protein replacement therapies, many of which are derived from blood products. Thus, the target populations may have a high prevalence of blood-borne pathogens, such as hepatitis C virus (HCV). We sought to determine whether the safety of recombinant adeno-associated virus serotype 2 (rAAV2) would be altered by preexisting HCV infection. Doses of approximately 1 x 10(13) vector genomes of an rAAV2-chimpanzee alpha(1)-antitrypsin (rAAV2-cAAT) vector were injected into the portal vein of each of three HCV genome-positive (HCV+) chimpanzees and three HCV-negative (HCV-) controls. Acute safety studies were performed up to 90 days after vector administration, along with analyses of the peripheral blood and liver tissue for rAAV2-cAAT genomes. Vector genome copy numbers in blood and liver tissue were similar in both groups. All animals demonstrated increases in liver and muscle enzyme levels after the pretreatment liver biopsy (5 days before vector injection) and after the vector injection. However, HCV+ animals demonstrated a substantially greater rise in aspartate aminotransferase, alanine aminotransferase, and creatinine phosphokinase values than HCV- animals. Histopathology demonstrated abnormal lipid accumulation (steatosis) in the hepatocytes of HCV+ animals, both before and after vector injection. These data indicate an increased susceptibility to subclinical liver toxicity from portal vein injection of rAAV2 in the presence of HCV infection.

Renal artery embolization: application and success in patients with renal cell carcinoma and angiomyolipoma.

Renal artery embolization is a procedure primarily performed by interventional radiologists that can be utilized for treatment of renal tumors, both malignant and benign. It has many applications, including pretreatment of renal cell carcinomas prior to planned resection to decrease hemorrhagic complications intraoperatively, treatment of malignant renal tumor in patients who are not deemed suitable surgical candidates, as well as treatment of benign renal tumors and their potential hemorrhagic complications. There are many different techniques. We describe how the procedure is approached at the University of Florida-Gainesville and provide examples of two cases, a renal cell carcinoma and an angiomyolipoma, treated at our institution with transcatheter embolotherapy.

Budd-Chiari syndrome: hepatic venous web outflow obstruction treated by percutaneous placement of hepatic vein stent.

Budd-Chiari syndrome (BCS) denotes a heterogeneous group of diseases characterized by hepatic venous outflow obstruction at the level of the hepatic veins or inferior vena cava resulting in portal hypertension. Traditional approach to treatment of BCS involves systemic thrombolysis and surgical portosystemic shunt or transjugular intrahepatic portosystemic shunt in progressive cases of BCS or as a bridge to transplantation. Recently, an increasing number of successful reports of BCS therapy have involved endovascular techniques, including angioplasty and stent placement. The present report illustrates successful percutaneous recanalization of complete hepatic vein occlusion by angioplasty and stent implantation in a patient with membranous obstruction.

Spurious hypocalcemia after gadodiamide-enhanced magnetic resonance imaging: a case report and review of the literature.

Gadolinium-enhanced magnetic resonance imaging is a diagnostic modality widely used in urologic practice. We report on a 54-year-old woman in whom a critically low serum calcium level was measured with standard colorimetric assay after gadodiamide-enhanced magnetic resonance imaging. The same phenomenon was noted in 2 other patients seen in our practice. Repeat serum calcium measurements performed several hours later were within normal limits. Commercially available gadolinium-based contrast agents might precipitate critically low serum calcium values when measured by standard colorimetric assay. Physician awareness of gadodiamide-induced spurious hypocalcemia might prevent unnecessary therapeutic interventions.

Efficacy and safety results with the LifeSite hemodialysis access system versus the Tesio-Cath hemodialysis catheter at 12 months.

PURPOSE: To compare the performance and safety of a fully subcutaneous vascular access device, the LifeSite hemodialysis access system, versus a tunneled hemodialysis catheter, the Tesio-Cath, at 1 year after implantation. MATERIALS AND METHODS: Sixty-eight patients who required hemodialysis received implantation of the LifeSite device or a Tesio-Cath device as a part of this multicenter study. Thirty-four patients were treated in each group. The endpoints observed included blood flow rates and associated venous pressures, overall and device-related adverse events, the need for thrombolytic infusions, device-related infections (DRIs) and associated hospitalizations, and technical device survival. RESULTS: During the 12-month observation period, significantly higher venous pressures were required in patients with the Tesio-Cath to achieve blood flow rates comparable with those achieved with the LifeSite device. Patients in the LifeSite group experienced a significantly lower rate of non-device-related adverse events (P < .001), device-related adverse events (P < .016), need for thrombolytic infusions (P < .002), and DRIs (P < .013) compared with patients in the Tesio-Cath group. There was a trend toward a lower number of hospital days per month for DRIs in the LifeSite group, with the rate for the Tesio-Cath group being twice that in the LifeSite group. The use of the LifeSite device was also associated with a significantly higher probability of device survival for 12 months after censoring for planned removals (P < .031). CONCLUSIONS: The results of the present study demonstrate superior device performance and technical device survival, reduced complications, and the need for fewer interventions with the LifeSite hemodialysis access system compared with a standard hemodialysis catheter during a 1-year time period after implantation.

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. CONCLUSION: CO2 splenoportography is safe and expedient and provides adequate visualization of the portal system for surgical planning in selected patients.