M. Dagli

Removal of retrievable inferior vena cava filters with computed tomography findings indicating tenting or penetration of the inferior vena cava wall.

PURPOSE To examine the feasibility and safety of removing retrievable inferior vena cava (IVC) filters with struts external to the IVC wall on computed tomography (CT) imaging. MATERIALS AND METHODS This retrospective study included 64 IVC filter retrievals from 62 patients over a 5-year period. CT images obtained before retrieval were used to describe the various imaging characteristics of filter interactions with the IVC wall. Patient medical records were reviewed for filter type, results of filter removal with standard or nonstandard techniques, and complications. RESULTS Filter struts outside the IVC wall were a common finding on CT with 55 (85.9%) filters showing some degree of perforation. Of 64 filters, 57 (89.1%) were removed successfully; 7 (10.9%) filters could not be removed because of incorporation of filter struts or tip into the IVC wall. Before retrieval, filter fracture was detected in eight (12.5%) cases, and IVC stenosis was present in three (4.7%) cases. No major complications occurred during any retrieval. Two (3.1%) cases were complicated by postprocedure abdominal pain. Both cases clinically resolved, and no abnormalities were detected on postprocedure CT. CONCLUSIONS The appearance of filter struts tenting or penetrating the IVC wall is a common finding on CT performed before filter retrieval. IVC filters with these findings can be removed safely and should not be a contraindication for IVC filter retrieval.

Silicone and Polyurethane Tunneled Infusion Catheters: A Comparison of Durability and Breakage Rates

PURPOSE To examine the overall durability and breakage rates of dual-lumen silicone catheters in comparison with power-injectable dual-lumen polyurethane catheters. MATERIALS AND METHODS Patients who received a 10-F dual-lumen silicone catheter or 9.5-F dual-lumen polyurethane catheter between January 2002 and July 2009 were identified through a quality assurance database. Medical records were reviewed retrospectively. A total of 117 silicone and 94 polyurethane catheters were identified in 192 patients. Reasons for catheter placement and removal were recorded, as were cases of breakage and repairs. Catheter durability was compared; survival analysis was also performed. RESULTS Breakage occurred in nine of 117 silicone catheters (8%) and none of 94 polyurethane catheters (P = .005). Most catheters were placed for malignancy (162 of 211; 77%); nonmalignant indications such as total parenteral nutrition accounted for 49 out of 211 catheters (23%). The mean silicone catheter dwell time was 99 days (11,612 total catheter-days), and the mean polyurethane catheter dwell time was 78 days (7,362 total catheter-days). There was no significant difference in overall duration of function (ie, survival) between silicone and polyurethane catheters (P = .12). The infection rates were 3.6 per 1,000 catheter-days for silicone catheters and 3.5 per 1,000 catheter-days for polyurethane catheters (P value not significant). CONCLUSIONS There were fewer catheter fractures with the polyurethane catheter compared with the silicone catheter, although there was no difference in the total access site service interval for the two catheter types.

Long-Term Outcomes of a Benign Biliary Stricture Protocol

PURPOSE To evaluate long-term outcomes of a structured protocol for percutaneous treatment of benign biliary stricture. MATERIALS AND METHODS Seventy-one patients (37 men, 34 women; mean age, 54 y; age range, 23-84 y) entered the protocol, which consisted of staged upsizing of internal/external biliary catheters, balloon dilation (nominally 8 mm), and prolonged stent treatment (6 mo) at maximal catheter size (nominally 18 F). It concluded with a capping trial and catheter removal if the stricture remained patent. Fifty-three patients completed the protocol and 18 did not (6 died, 6 underwent alternative treatment, 4 were lost to follow-up, and 2 underwent repeat transplantation). Stricture features, treatment parameters, complications, and outcomes were reviewed, and Kaplan-Meier analysis was conducted. RESULTS Strictures were anastomotic in 45 patients (64%), intrahepatic in 14 (20%), extrahepatic in 7 (10%), and multiple (intra- and extrahepatic) in 5 (7%). A right-sided approach was used in 47 patients (66%) patients, a left-sided approach in 18 (25%), and a bilateral approach in 6 (9%). Forty-six patients who entered the protocol (65%) and 46 patients who completed the protocol (87%) showed stricture patency. Four of 7 patients in whom a capping trial failed underwent surgical revision, 2 required chronic biliary drainage, and 1 received a metal stent. Follow-up (range, 0-12 y; mean, 4.7 y) was obtained for 42 of 53 patients who completed the protocol (79%). Kaplan-Meier analysis showed stricture patency probabilities of 84% at 1 year after treatment, 78% at 2 years, 74% at 5 years, and 67% at 10 years. CONCLUSIONS Use of a structured protocol for the percutaneous treatment of benign biliary strictures yields durable long-term results, suggesting that percutaneous treatment is an effective therapy.

Malfunctioning and Infected Tunneled Infusion Catheters: Over-the-Wire Catheter Exchange versus Catheter Removal and Replacement

PURPOSE To compare the safety and effectiveness of over-the-wire catheter exchange (catheter-exchange) with catheter removal and replacement (removal-replacement) at a new site for infected or malfunctioning tunneled infusion catheters. MATERIALS AND METHODS Using a quality assurance database, 61 patients with tunneled infusion catheters placed during the period July 2001 to June 2009 were included in this study. Patients receiving hemodialysis catheters were excluded. Catheter-exchange was performed in 25 patients, and same-day removal-replacement was performed in 36 patients. Data collected included demographic information, indication for initial catheter placement and replacement, dwell time for the new catheter, and ultimate fate of the new device. Statistical comparisons between the two cohorts were analyzed using the Kaplan-Meier technique and Fisher exact test. RESULTS Catheters exchanged over the wire remained functional without infection for a median of 102 days (range, 2-570 days), whereas catheters removed and replaced were functional for a median 238 days (range, 1-292 days, P = .12). After catheter replacement, there were 11 instances of subsequent infection in the catheter-exchange group and 7 instances in the removal-replacement cohort, accounting for infection rates of 4.4 and 2.3 per 1,000 catheter days (P = .049). Patients in the catheter-exchange group had 3.2 greater odds of infection compared with patients in the removal-replacement group. Five malfunction events occurred in each group, accounting for 2.0 and 1.7 malfunctions per 1,000 catheter days in the catheter-exchange and removal-replacement groups (P = .73). CONCLUSIONS Catheter-exchange of tunneled infusion catheters results in a higher infection rate compared with removal-replacement at a new site. The rate of catheter malfunction is not significantly different between the two groups. Catheter-exchange is an alternative for patients with tunneled infusion catheters who have limited venous access, but this technique should not be expanded for use in all patients. Because of the size of this initial study, further investigation is needed to verify the results in a larger sample size.

Recurrent Bleeding, Survival, and Longitudinal Pulmonary Function following Bronchial Artery Embolization for Hemoptysis in a U.S. Adult Population.

PURPOSE To report outcomes of bronchial artery embolization (BAE) for hemoptysis, including recurrent bleeding, survival, and longitudinal pulmonary function. MATERIALS AND METHODS A prospective database identified 69 patients who underwent 97 BAE procedures (n = 1-7 per patient) at a tertiary academic medical center over a period of 11 years. Technical and clinical success were determined. Recurrent bleeding and survival were compared by etiology of lung disease. Rates of change in pulmonary function (forced expiratory volume in 1 s [FEV1] and forced vital capacity [FVC]) were measured and compared before and after index BAE by linear regression in 17 patients. RESULTS The technical success rate of BAE was 90%. Clinical success rates at 24 hours and 30 days were 82% and 68%, respectively. Thirty percent of patients had recurrent bleeding that required bronchoscopy (7%) or additional embolization (23%). Median time to recurrent bleeding was 29 days among the 13 patients with sarcoidosis, compared with 293 days among patients without sarcoidosis (P = .0013). The hazard ratio for death in patients with sarcoidosis compared with those without sarcoidosis was 4 (95% confidence interval, 2.6-14.6). Analyzing all instances of pulmonary function tests, slopes of decline in FEV1 and FVC were significantly different (FEV1, P = .0048; FVC, P < .0001) before and after index BAE, with an improvement after BAE (FEV1, 0.8%/y; FVC, 1%/y) and a decrease before BAE (FEV1, -1.6%/y; FVC, -1.4%/y). CONCLUSIONS BAE is an effective therapy for hemoptysis, but patients with sarcoidosis are at significant risk of recurrent bleeding and death compared with patients with other lung diseases. BAE does not accelerate deterioration in lung function.

Catheter-based Intraaccess Blood Flow Measurement as a Problem-solving Tool in Hemodialysis Access Intervention

PURPOSE To investigate retrospectively the use of catheter-based intraaccess blood flow measurements as an adjunct to physical examination and fistulography in hemodialysis access interventions. MATERIALS AND METHODS Among 1,540 dialysis interventions performed at a single institution in a 2.5-year period, 104 qualifying catheter-based flow measurements were made in 70 mature native fistula interventions in 55 patients and 34 graft interventions in 31 patients. The flow rate threshold prompting intervention was generally 600 mL/min, but some variation existed depending on the clinical setting. RESULTS The most common indication for measurement of blood flow was to determine the hemodynamic significance of a fistula inflow stenosis (n = 25), of which only four had subsequent intervention. Other common indications included decision-making resulting in further angioplasty or stent implantation of noninflow lesions (fistulas, n = 10; grafts, n = 23) versus termination of the procedure (n = 23), problem-solving in cases in which there was no visible lesion to explain the clinical indicator of access failure (n = 17), evaluation for high-flow-related cardiac risk in aneurysmal fistulas (n = 13), suboptimal evaluation of the inflow (n = 8), and suboptimal physical examination (n = 6). Overall, flow measurements supported a decision to perform angioplasty (n = 11) or stent placement (n = 3) in 17% of fistula interventions and 35% of graft interventions. CONCLUSIONS The major benefit of flow measurement was to support a decision to withhold further angioplasty or stent placement.

Evaluation of Immature Hemodialysis Arteriovenous Fistulas Based on 3-French Retrograde Micropuncture of Brachial Artery

OBJECTIVE The objective of our study was to assess outcomes after evaluation of immature hemodialysis arteriovenous fistulas (AVFs) via 3-French brachial artery access and to identify the incidence of arterial and venous puncture site spasm. MATERIALS AND METHODS One hundred twenty-three outpatients (82 men, 41 women; mean age, 58 years; age range, 20-90 years) with immature AVF were identified retrospectively in whom diagnostic fistulography was performed via 3-French retrograde brachial artery puncture. Percutaneous transluminal angioplasty was performed via a separate venous puncture during the same visit in 95 patients. Patient age and sex, fistula age and type, and technical success and complications were recorded. Images were reviewed for lesion location, potentially competing vessels, and arterial and venous puncture-related spasms. RESULTS The mean fistula age was 99 days (range, 21-639 days). There were 49 AVFs in the left forearm; 30 in the left upper arm; 26 in the right forearm; and 18 in the right upper arm. Twenty-eight AVFs were transposed. Angioplasty was technically successful in 81 of 95 patients (85%; mean diameter, 7 mm; range, 4-10 mm). Brachial artery puncture caused no major complication. Arterial spasm occurred in 19 patients (15%) and was severe in one patient. There were two hematomas (1.6%). Venous spasm, ranging from mild (four patients) to occlusive (8 patients), occurred in 38 patients (40%) at the site of venipuncture for intervention. Nitroglycerin (mean, 325 mcg; range, 100-600 mcg) was used in 26 procedures (21%). Venous spasm was more common with forearm (50%) than upper arm (24%) fistulas (p = 0.02) and with decreasing vein diameter (p = 0.02). CONCLUSION Evaluation of immature AVFs based on 3-French micropuncture of the brachial artery can be safely performed on an outpatient basis. Spasm is more common in forearm AVFs and in smaller veins.

Effect of Central Venous Angioplasty on Hemodialysis Access Circuit Flow: Prospective Study of 25 Symptomatic Patients

PURPOSE To quantify the effect of central venous percutaneous transluminal angioplasty (PTA) on blood flow within hemodialysis access circuits in patients with symptomatic central venous stenosis (CVS). MATERIALS AND METHODS This prospective study enrolled 30 adults with symptoms attributable to CVS ipsilateral to their access. Five subjects were deregistered because of a lack of CVS (n = 1), untreatable lesion (n = 1), or improper flow measurement timing (n = 3); 25 completed the study (15 men and 10 women; mean age, 62 y; age range, 33-87 y). There were 7 fistulae, 15 grafts, and 3 hybrid access circuits. Mean access age was 675 days (range, 16-3,039 d). Mean CVS symptom duration was 37 days (range, 3-120 d). Peripheral stenoses, if present, were treated first. Intraaccess flow was measured immediately before and immediately after CVS treatment (PTA, stent). RESULTS Eleven patients had only CVS, whereas 14 had at least 1 peripheral lesion in addition to CVS. All stenoses underwent PTA. Mean flow rates were 1,424 mL/min (range, 565-2,765 mL/min) before PTA and 1,535 mL/min (range, 598-2,545 mL/min) afterward, yielding a mean increase of 111 mL/min ± 456 or 15% ± 34 (range, -70% to +100%; 95% confidence interval, 1%-29%). Flow was decreased in 9 patients (36%). CVS symptoms were reduced in 24 patients (96%) and recurred in 14 (58%) within a mean of 110 days (range, 7-459 d) after initial PTA. Mean follow-up was 371 days (range, 17-592 d). CONCLUSIONS CVS symptoms were observed to occur over a wide range of blood flow rates. On average, central venous PTA only mildly increased flow yet reduced symptoms regardless of flow change.

Effect of Substituting 50% Isovue for Sterile Water as the Delivery Medium for SIR-Spheres: Improved Dose Delivery and Decreased Incidence of Stasis.

Purpose The objective of this study was to evaluate the effect of substituting 50% Isovue (Bracco Diagnostics Inc, Monroe Township, NJ) for sterile water on the delivery of 90Y resin microspheres (SIR-Spheres [Sirtex Medical Limited, Sydney, Australia]). Materials and Methods The authors retrospectively reviewed all SIR-Spheres radioembolizations at the authors’ institution from January 1, 2011, to February 10, 2014. From January 1, 2011, to April 30, 2013, all users performed SIR-Spheres radioembolization per the manufacturer’s original instructions using sterile water in the B and D lines and intermittently checking the progress of the embolization by injecting contrast via the B line. Beginning May 1, 2013, a modified technique using Isovue diluted 50% with saline in place of sterile water in both the B and D lines of the infusion set. The authors compared the prepared versus administered activity of 90Y SIR-Spheres, fluoroscopy time, administration time, and frequency of radioembolizations terminated for stasis when using water versus dilute contrast in the B and D lines. Results One hundred seventy-five radioembolizations were performed, 132 (75%) with water as the delivery medium and 43 (25%) with 50% contrast as delivery medium. The mean percentage of the 90Y activity administered was 98% with contrast versus 87% with water (P < 0.01). More than 95% of cases using contrast resulted in 90% or more delivery of the prepared 90Y activity versus 59% of cases with water (P < 0.01). For cases using water, 17% were terminated for stasis, whereas 2% (1 case) using contrast was terminated for stasis. The mean 90Y administration time was 7 minutes with contrast versus 22 minutes with water (P = 0.015). Excluding the 37 cases involving coil embolization, the mean fluoroscopy time was 8.3 minutes with contrast versus 11.5 minutes with water (P < 0.05). No complications occurred with the contrast method; however, there were 4 complications with water, including 1 nontarget gastric ulceration. Conclusions Using dilute contrast as the delivery medium for SIR-Spheres resulted in a significantly greater percentage of the prepared activity administered to the patient with substantially shorter administration time. Termination for stasis occurred less often with dilute contrast. No complications were observed when using dilute contrast, which allowed continuous real-time monitoring of the 90Y microsphere administration.

Initial Clinical Experience: Symmetric-Tip Dialysis Catheter with Helical Flow Characteristics Improves Patient Outcomes

PURPOSE To report preliminary clinical experience with a new symmetric-tip dialysis catheter compared with a conventional split-tip catheter. MATERIALS AND METHODS Over a 5-month period, patients requiring a tunneled catheter for hemodialysis or undergoing exchange of a dysfunctional dialysis catheter at a tertiary academic medical center were retrospectively analyzed. Patients underwent placement of a VectorFlow or Ash Split Cath catheter at the discretion of the inserting interventional radiologist. Patient demographics, catheter patency, mean blood flow rate, and arterial and venous pressures were compared according to catheter type. Catheter failure was analyzed based on clinical and anatomic variables by using a multivariate Cox proportional-hazards model. RESULTS A total of 33 VectorFlow and 46 Ash Split Cath catheters were placed. Patients in the VectorFlow group had significantly higher body mass index (P = .013) and Charlson Comorbidity Index (P = .049), as well as more non-internal jugular vein placements. At 120 days, 89% of VectorFlow catheters remained functional, compared with 45% of Ash Split Cath catheters (P = .046). The VectorFlow catheter was associated with 16% lower arterial pressures during dialysis (P = .009); mean blood flow rate was equivalent. On multivariate analysis, the risk of catheter failure was 13.3 times higher in the Ash Split Cath group compared with the VectorFlow group (P = .004). Left-sided catheters were also predictive of catheter failure (relative risk = 5.5; P = .02). CONCLUSIONS The VectorFlow catheter was associated with a significant increase in intervention-free catheter patency compared with the Ash Split Cath catheter, with equivalent flow at lower arterial pressures during dialysis.