A new catheter type for superselective angiography and embolization

PURPOSE AND MATERIAL: A new family of catheters was developed to overcome the shortcomings of conventional catheters and to avoid the use of coaxial catheters in superselective angiography and embolization. The new catheter is nylon, 1.67 mm (JF) long, and has a rigid proximal part (to ensure torque control and pushability) and a long 2-step flexible tip (to follow arterial tortuosities). It has a hydrophilic coating, and a long-lasting shape memory. This new catheter type was compared experimentally with conventional catheters. RESULTS: Clear advantages were found with the new catheters in pushability and trackability as they, more often than conventional catheters, permitted us to reach the periphery of an artery. Departmental experience with the new catheters currently amounts to over 500 arterial procedures. CONCLUSION: The new catheters could frequently replace coaxial catheters, which would contribute towards reducing the costs of intravascular procedures.     

Filling hemodialysis catheters in the interdialytic period: heparin versus citrate versus polygeline: a prospective randomized study

Heparin and saline are commonly used to fill hemodialysis central venous catheters to prevent their thrombosis during the interdialytic period. The purpose of this prospective clinical study was to evaluate whether replacing heparin with citrate or polygeline could ensure satisfactory catheter function without exposing patients to the risk of systemic heparinization. Thirty end-stage renal disease (ESRD) patients with subclavian or jugular single lumen catheters as temporary vascular access for hemodialysis were enrolled. After the insertion of the catheters, the patients were randomly assigned to one of the following three filling groups: Group A, heparin; Group B, citrate; Group C, polygeline. Before each dialysis, the filling solution was aspirated and clot volume, if present, was measured. The catheter usage time and the clot volume were 23 +/- 24 days and 0.052 +/- 0.035 ml in Group A, 51 +/- 36 days and 0.059 +/- 0.032 ml in Group B, and 32 +/- 10 days and 0.056 +/- 0.038 ml in Group C, respectively. Our results indicate that citrate or polygeline can replace heparin effectively as a filling solution for single lumen temporary hemodialysis catheters.     

Simple reinforcement for thin nephrostomy catheters

PURPOSE: Nephrostomy catheters are prone to kinking or damage because the thin, flexible silicone tube is too vulnerable against mechanical stress even when the proximal end is carefully fixed. We developed a simple method to reinforce the outside part of a thin catheter protruding from the skin. MATERIALS AND METHODS: We treated 7 children with nephrostomy catheters or ureteral stents with a diameter of 8F or smaller. After insertion a large plastic tube was wrapped around the small catheter, and fixed to the skin and to the peripheral collection system with adhesive tape. RESULTS: Handling of the catheters improved and there was less need for re-fixation. CONCLUSIONS: Thin nephrostomy catheters can be effectively protected by wrapping them into a larger, outer tube after insertion.     

Analytical and biologic variability in measures of hemostasis, fibrinolysis, and inflammation: assessment and implications for epidemiology

CONTEXT: Central venous catheters impregnated with chlorhexidine and silver sulfadiazine have recently been introduced for the prevention of catheter-related infections. However, there remains some uncertainty regarding the efficacy of these catheters because of conflicting reports in the literature. OBJECTIVE: To evaluate the efficacy of chlorhexidine-silver sulfadiazine-impregnated central venous catheters in the prevention of catheter-related bloodstream infection. DATA SOURCES: Studies identified from a computerized search of the MEDLINE database from January 1966 to January 1998, reference lists of identified articles, and queries of principal investigators and the catheter manufacturer. STUDY SELECTION: Randomized trials comparing chlorhexidine-silver sulfadiazine-impregnated central venous catheters with nonimpregnated catheters were included. The outcomes assessed were catheter colonization and catheter-related bloodstream infection confirmed by catheter culture. DATA EXTRACTION: Twelve studies met the inclusion criteria for catheter colonization and included a total of 2611 catheters. Eleven studies with a total of 2603 catheters met the inclusion criteria for catheter-related bloodstream infection. Most patients in these studies were from groups considered to be at high risk for catheter-related infections. Summary statistics were calculated using Mantel-Haenszel methods under a fixed-effects model. DATA SYNTHESIS: The summary odds ratio for catheter colonization was 0.44 (95% confidence interval [CI], 0.36-0.54; P<.001), indicating a significant decrease in catheter colonization associated with impregnated catheters. The studies examining the outcome of primary interest, catheter-related bloodstream infection, had a summary odds ratio of 0.56 (95% CI, 0.37-0.84; P = .005). CONCLUSIONS: Central venous catheters impregnated with a combination of chlorhexidine and silver sulfadiazine appear to be effective in reducing the incidence of both catheter colonization and catheter-related bloodstream infection in patients at high risk for catheter-related infections.     

Catheter infection in intensive care: influence of systematic replacement of central venous catheters on a guide wire every 4 days

OBJECTIVES: Determine whether systematic replacement of central venous catheters on a guide wire every 4 days leads to a lower rate of catheter infection. METHODS: We conducted a prospective randomized study comparing systematic catheter replacement with the standard procedure where one-way catheters are left in situ as needed. RESULTS: The study included 150 patients and 170 catheters. Catheter replacement on a guide wire was performed 169 times. The rate of infection was not significantly different between the group of patients with replacement (3.7 for 1000 catheter days) and the group with systematic replacement (5.4 for 1000 catheter days). No mechanical complications occurred during the replacement procedures on guide wires. CONCLUSION: We do not recommend systematically replacing catheters on a guide wire for the prevention of catheter infection. This procedure may however be indicated in case of suspected catheter infection as no mechanical of infectious complications occurred.     

Transient up-regulation of ciliary neurotrophic factor receptor-alpha mRNA in axotomized rat septal neurons

PURPOSE: To determine prospectively the feasibility, complications, and mid- and long-term advantages of peripheral insertion of central catheters in infants and children. MATERIALS AND METHODS: During a 15-month period between March 1995 and June 1996, a total of 285 catheter placement attempts were made to peripherally insert central catheters in 183 pediatric patients (89 boys, 94 girls). Phlebographic guidance was used, and the catheters were inserted below the elbow in 99% of cases. Catheter insertion was indicated for prolonged antibiotic therapy in 108 patients (158 catheter placement attempts), hematologic or oncologic care in 24 patients (40 attempts), total parenteral nutrition in 16 patients (46 attempts), and venous access for fluid or blood in 35 patients (41 attempts). The success rate and complications were recorded along with the indication, patient age, and duration of catheter placement. RESULTS: One hundred fifty-two of 158 (96%) catheter placement attempts were successful in outpatients (n = 108), 124 of 127 (98%) in hospitalized patients (n = 75), and 70 of 73 (96%) in patients aged less than 1 year. Infection and pericatheter venous thrombosis were the main complications and were seen in 17 of 276 (6%) and one of 276 (0.3%) catheter placement attempts, respectively. Catheter occlusion occurred in 23 of 276 (8%) catheter placement attempts. CONCLUSION: Peripheral insertion of central catheters was highly feasible in infants and children with this protocol. Such catheters were well tolerated in the pediatric population with a low frequency of complications.     

Interleukin-12 gene-expression of macrophages is regulated by nitric oxide

PURPOSE: To determine the origin of subclavian vein catheter and lead dysfunction. MATERIALS AND METHODS: Cineradiography was performed on 10 patients with subclavian venous catheter dysfunction and three patients with pacemaker or defibrillator lead dysfunction. The leads and catheters were removed and replaced with use of a fluoroscopically guided technique; the needle entered the vein lateral to the first rib. Repeat cine examinations were performed following placement of new catheters. RESULTS: The cause of the dysfunction of all 10 catheters was shown to be pinch by the subclavicular musculotendinous tissues as the catheter passed below the clavicle toward its entry into the vein. All three leads were entrapped in the subclavicular tissues and stretched during abduction. The abnormal motion and clinical problems were eliminated after replacement. CONCLUSION: Subclavian catheter and lead malfunction is not due to compression between the first rib and the clavicle. It is due to entrapment in the subclavius muscle-costoclavicular ligament complex, which binds or compresses the device during movements. These problems can be avoided by employing fluoroscopically guided puncture techniques that enter the vein lateral to the first rib.     

Use of optical catheters for diagnostic office laparoscopy

OBJECTIVE: To evaluate several small optical catheters (1.8-mm outer diameter) developed to allow access to the pelvic cavity for laparoscopic diagnosis in the operating room and in an office setting. STUDY DESIGN: Thirty-six procedures are reported, 20 performed in the operating room so that proper placement could be monitored and ensured, and the findings were compared with those obtained with a standard, 10-mm laparoscope. The remaining 16 procedures were performed in an office setting. The patients were women who were candidates for second-look laparoscopy, had pelvic pain and no physical findings, or were evaluated for possible tubal anastomosis. CONCLUSION: The small, rigid catheter, with its excellent optics, provided a clear view of the pelvis without the need for general anesthesia and associated costs. The procedure was performed easily and successfully with a local anesthetic and with minimal discomfort for the patient.     

Safety and efficacy of hydrogen peroxide plasma sterilization for repeated use of electrophysiology catheters

OBJECTIVES: The purpose of this study was to evaluate a new technique for sterilizing nonlumen electrophysiology catheters that uses hydrogen peroxide gas plasma. BACKGROUND: The reuse of electrophysiology catheters may potentially result in a significant cost savings. While ethylene oxide sterilization appears to be safe and effective from a clinical standpoint, toxic ethylene oxide residuals, which exceed Food and Drug Administration standards, have been reported. METHODS: Ten nonlumen electrophysiology catheters were extensively evaluated. Each catheter was used five times and resterilized after each use with hydrogen peroxide gas plasma. Tests for sterility, mechanical and electrical integrity, chemical residuals and standard and electron microscopic inspection were performed. RESULTS: Loss of electrical integrity or mechanical integrity was not observed in any catheter. No evidence of microbial contamination was found. Surface integrity was preserved except for one ablation catheter that exhibited fraying of the insulation at the insulation-electrode interface. Surface inspection using standard magnification and electron microscopy revealed no significant change in surface characteristics associated with the sterilization process. Hydrogen peroxide was the only chemical residual noted, with an average concentration of 0.22% by weight, which is within accepted American Association for the Advancement of Medical Instrumentation limits. The cost for a standard electrophysiology catheter ranges from $200 to $800, and one sterilization cycle costs $10. If electrophysiology catheters are used five times, resterilization could potentially result in a savings of $2,000 per catheter, or $9,000 for five ablation procedures. CONCLUSIONS: Hydrogen peroxide gas plasma sterilization may provide a cost-effective means of sterilizing nonlumen electrophysiology catheters without the problem of potentially harmful chemical residuals. However, careful visual inspection of catheters, particularly at the insulation-electrode interface, is required if catheter reuse is performed.     

Central venous catheter failure is induced by injury and can be prevented by stabilizing the catheter tip

PURPOSE: Thrombosis associated with central venous catheters is a significant cause of device failure, morbidity, and loss of access sites. We hypothesized that central vein thrombosis is caused by catheter injury to the vein wall and that it can be reduced by stabilizing the catheter tip. To test these hypotheses, we studied central vein catheters in a porcine model. Test catheters had a silicone-encased stainless steel loop at the indwelling end that contacted the vein wall and stabilized the catheter tip in the center of the vessel. METHODS: Sealed silicon elastic (Silastic) catheters (3.2 mm outer diameter) with and without a stabilizing loop were inserted via the external jugular vein into the superior vena cava just above the right atrium. Animals were killed at 1, 2, 4, and 8 weeks, and the vena cava was inspected for the presence of thrombus and entrapment of the catheter tip. RESULTS: In control animals mural thrombus developed at the site of the catheter tip. This thrombus organized by invasion of macrophages and smooth muscle cells, eventually forming a lesion similar to intimal hyperplasia. Lesion cross-sectional area was significantly smaller in animals with loop catheters than in control animals at 2 weeks (1.2 +/- 1.3 vs 34.5 +/- 23.9 mm2; p = 0.05) and 4 weeks (2.8 +/- 0.3 vs 13.9 +/- 5.8 mm2; p < 0.05). By 8 weeks the vena cava was nearly occluded in most animals and the catheter tip was entrapped in this lesion in all cases. Test catheters eliminated the injury process for up to 8 weeks (p < 0.01, chi2 control vs loop catheter entrapment). Very little injury response was found where the loop contacted the vein wall, and the catheter tip was free of thrombus in all cases. CONCLUSIONS: Mural thrombosis at the tip of indwelling central catheters is caused by chronic mechanical venous wall injury. Vessel injury and the resulting thrombosis can be prevented by a catheter modification that stabilizes the tip. Such a catheter may significantly reduce catheter malfunction and morbidity associated with these devices.     

Effects of gallstone solvents on commonly used catheters

PURPOSE: To determine what interaction and effect different cholesterol gallstone solvents have on catheters used for gallstone chemolysis. MATERIALS AND METHODS: Five types of catheters used for biliary procedures were chosen: polyethylene, Percuflex, silicon, Silitek, and polyurethane. The solvents chosen were methyl tert-butyl ether, ethyl propionate, isopropyl acetate, and N-propyl acetate. After incubation of the catheters in the solvents for 72 hours, they were air dried. Weight and area changes were determined for each catheter. Additionally, carbon-13 nuclear magnetic resonance (NMR) spectroscopy was performed for analysis of composition changes. RESULTS: Three catheters--silicone, Silitek, and polyurethane--showed changes in their physical characteristics that would make them less desirable for stone chemolysis. The silicone catheter showed changes in elastic texture as well as marked weight reduction. The Silitek and polyurethane catheters had similar, but less dramatic changes. C-13 NMR analysis of collected solvents showed that commonly used plasticizers were leached out of some catheters. CONCLUSION: These results suggest that all catheters are not suitable for use with all solvents. The choice of catheter should be made based on the solvent in use. The polyethylene catheter performed best under the conditions and endpoints used in this study.     

In vivo evaluation of the new antithrombogenic reservoir-catheter coated with polymer blend copolymer

We evaluated the antithrombogenicity of 4F-catheters coated with the new antithrombogenic material fluorine-acryl- styrene-urethane-silicone (FASUS) graft-block copolymer by dissecting microscopic and scanning electron microscopic observations. These catheters were temporarily used for the infusa-A-port, which was prepared for the treatment of four patients with bladder cancer. Two heparin-coated catheters were also evaluated. All FASUS-coated catheters contained thrombi consisting of red thrombi and/or fibrin thrombi. Massive red thrombus was seen at the site of curvature of the catheters, 1 cm distal to the tip of the catheter. However, the portion 20 cm distal to the tip of the catheter had no red thrombus, but contained minimal fibrin thrombus or plasma protein. The heparin-coated catheters showed the same findings as the FASUS catheters. The FASUS-coated catheters were not superior in antithrombogenicity to the heparin-coated catheters. It was concluded that the FASUS-coated catheters used in this study seemed to have problems in regard to their preshaped curvature and the material used in catheter. These aspects need to be improved.     

Prospective study of infective complications in newborns with fine silicone catheters used for parenteral nutrition infusion

OBJECTIVE: Percutaneous silastic central venous catheters have contributed to improve the care of neonates. They are quite safe; however, sometimes complications occur, with infections being the most frequent. A prospective study was undertaken in our NICU to know the rate of catheter-related sepsis, the influence of the duration of catheterization, the predominant portal of entry and the microorganisms isolated. PATIENTS AND METHODS: Fifty-two catheters were analyzed. Cultures were obtained once a week by aspiration from the catheter hub, the luer-lock connection and parenteral nutrition solution directly from the bag. If sepsis was suspected, blood cultures were obtained from a different vein. The tip was cultured after catheter withdrawal by the semiquantitative technique of Maki. RESULTS: Nineteen catheters (36.5%), 19 luer-lock connections (21.3%) and 7 parenteral nutrition solutions were colonized. We found a significant increase of the rate of colonization after the catheter had been in place 3 weeks or more (p < 0.05). Coagulase negative Staphylococcus was isolated in 75.7% of the samples. The rate of catheter related sepsis was 15.4% (7/8 caused by coagulase negative Staphylococcus). CONCLUSIONS: Catheter related sepsis may be more frequent than expected it colonization of the catheter were analyzed systematically. Screening catheter colonization allows an earlier diagnosis of pathogens if sepsis develops. Finally, we believe that the use of sterile techniques to handle the catheter and connections will further decrease catheter related infections.     

The 2-His-1-carboxylate facial triad--an emerging structural motif in mononuclear non-heme iron(II) enzymes

PURPOSE: To determine in-line pressures generated in small-bore central venous catheters during power injection of computed tomographic (CT) contrast media. MATERIALS AND METHODS: Five 3.0-7.0-F central venous catheters for pediatric patients were tested at full and half lengths in vitro. In-line pressures were measured during power injection of three contrast media. Rates of injection were increased in steps from 0.1 to 5.0 mL/sec or until a peak pressure of 100 psi (700 kPa) was achieved. The maximum tolerated flow rate was determined with reference to the manufacturer's suggested operating pressure limit for each catheter. RESULTS: At full length, the maximum tolerated flow rates were as follows: 2-3 mL/sec for the large lumen and 1-1.4 mL/sec for the small lumen of the 7.0-F double-lumen catheter; 0.2-0.4 and 0.8-1.2 mL/sec for the 3.0- and 4.0-F peripherally inserted central catheters, respectively; 0.7-1.2 mL/sec for the 6.6-F catheter; and only 0.2 mL/sec for the 4.2-F catheter, which ruptured during testing at higher flow rates. CONCLUSION: Flow rates were documented at which certain small-bore central venous catheters should tolerate power injection of CT contrast media with peak pressures remaining below the manufacturer's recommended operating pressure limits. These data may serve as a guide for clinical use.     

Prevalence of nocardiosis in an area of endemic tuberculosis

OBJECTIVE: To assess the quantity and nature of the proteins that adsorb to hydrocephalus shunt catheters after implantation, and to determine whether sufficient could accumulate to obstruct the catheter. DESIGN: Elution of proteins from 102 explanted shunt catheters, with protein assay and electrophoresis of the eluate, and scanning electron microscopy (SEM) of the catheters. RESULTS: The amount of protein elutable was extremely low, and significant protein, apart from a thin film, was not found on SEM. Qualitative analysis disclosed that most of the adsorbed protein was albumin. CONCLUSIONS: Protein deposition on hydrocephalus catheters does not occur in sufficient quantities to cause catheter obstruction.     

Proteolytic processing of ricin A chain is not required for cytotoxicity

PURPOSE: To evaluate prospectively the use of peripherally inserted central catheters in a large pediatric population. MATERIALS AND METHODS: During a 3-year period, data were collected prospectively on 523 consecutive attempts to place peripherally inserted central catheters in children. Patients underwent radiologically guided placement because attempts were unsuccessful on the inpatient units or a patient request was made. Fluoroscopy with use of contrast material and venography were used to place catheters and document the position of the catheter tip. Follow-up data were collected until treatment cessation or catheter removal. RESULTS: Among 523 attempts, 486 (92.9%) catheters were successfully placed. In the 37 (7.1%) unsuccessful cases, more than half of these children were younger than 24 months of age or weighed less than 5 kg. Ages of patients in whom 523 placement attempts were made ranged from 3 weeks to 18 years (mean, 6.9 years). Catheters were in place from 1 to 390 days (mean, 20 days). Frequency of infection was 1.9% (nine cases); incidence of infection was 0.93 per 1,000 catheter-placement days. There were two cases (0.4%) of central venous thrombosis. Most patients were discharged within 2 days of catheter placement. CONCLUSION: Fluoroscopically guided placement of peripherally inserted central catheters is a safe and effective method for establishing intermediate- and long-term central venous access in the pediatric population.     

Interleukin-12 enhancement of antigen-specific lymphocyte proliferation correlates with stage of human immunodeficiency virus infection

OBJECTIVE: The purpose of this study was to evaluate the use and complication rate of tunneled femoral hemodialysis catheters placed in patients with no remaining thoracic venous access sites. MATERIALS AND METHODS: Over a 3-year period, 41 tunneled femoral vein catheters (35 right, six left) were placed in 21 patients (15 women, six men; 21-89 years old; mean, 52 years). Catheters ranged in length from 40 to 60 cm. Tips were positioned immediately above the iliac bifurcation, at the mid inferior vena cava (IVC), or at the junction of the IVC and right atrium. Catheters were exchanged through the existing tract if the flow rate decreased to less than 200 ml/min. Catheters were removed if an episode of bacteremia did not resolve with antibiotics or if the insertion site became infected. RESULTS: Technical success of placement was 100%. The 30-, 60-, and 180-day primary patency rates were 78%, 71%, and 55%, respectively. The 30-, 60-, and 180-day secondary patency rates were 95%, 83%, and 61%, respectively. Average time of function per intervention was 61 days. Infections requiring catheter removal occurred at a rate of 2.4 per 1000 catheter days. One episode of partial IVC thrombosis occurred after a catheter infection developed 78 days after initial catheter placement. No episodes of symptomatic pulmonary embolism occurred. Total length of follow-up was 2506 catheter days. CONCLUSION: Femoral vein catheters require more frequent interventions than do thoracic catheters and are more susceptible to infection. However, in patients with difficult central venous access, the common femoral vein may be successfully used for permanent tunneled hemodialysis access.     

Revision of dysfunctional Tenckhoff catheters by laparoscopic technique in continuous ambulatory peritoneal dialysis patients

A laparoscopic technique was used to rescue dysfunctional Tenckhoff catheters in five continuous ambulatory peritoneal dialysis (CAPD) patients. This method proved to be effective in recovering the function of the catheters, whose malfunction was found to be due to catheter entrapment or endoluminal tamponing by the omentum. The videoscope-assisted laparoscopic technique provides access and allows identification and eradication of the specific etiology leading to catheter drainage failure. It also provides an alternative for treating patients with a dysfunctional Tenckhoff catheter. This method avoids the need to remove the original catheter or to reimplant a new catheter.     

Comparative experience of a simple technique for laparoscopic chronic ambulatory peritoneal dialysis catheter placement

BACKGROUND: Chronic ambulatory peritoneal dialysis (CAPD) is now an established technique for renal dialysis. Patients with renal failure cope poorly with major surgery and it is vital that the dialysis catheter tip is sited accurately in the pelvis if long-term catheter function is to be achieved. Laparoscopic placement of CAPD catheters may have potential advantages for renal patients by avoiding the morbidity of a laparotomy. METHODS: A retrospective audit was performed of all CAPD catheters inserted at the John Hunter Hospital over a 2-year period. Results of laparoscopically inserted catheters and those placed at laparotomy were compared. RESULTS: Sixty catheters were inserted, 30 laparoscopically and 30 at laparotomy. The mean operative time was 41 min in the laparoscopic patients and 57 min in the laparotomy patients (P = 0.0001). The mean total dose of narcotic administered postoperatively was significantly less in the laparoscopic group (5 mg vs 65 mg, P = 0.00002). There were three minor peri-operative complications in the laparoscopic group and seven peri-operative complications in the laparotomy group, three required reoperation and one resulted in the patient's death. There were no significant differences in the incidence of exit-site infection, catheter blockage, peritonitis, and overall catheter survival, although the laparoscopically placed catheters had been followed up for a shorter period (10 vs 16 months). CONCLUSIONS: This laparoscopic technique is safe and effective. Postoperative pain was less than for open placement. Laparoscopically placed catheters had a low incidence of peri-operative complications. Medium-term patency is similar to conventionally placed catheters. This procedure requires no additional equipment to that available for laparoscopic cholecystectomy and takes less time than the open operation.     

Comparison of the effects of Ca2+ and those of Mg2+ and La3+ on endplate currents in mouse interosseus muscles

Intravascular ultrasound imaging (IVUS) is a new method that permits in vivo visualization of central venous catheters with hitherto unknown image resolution. It provides information not only about thrombus formation, but also about catheter movement, catheter malposition, and vessel wall injuries. In the present investigation the method was applied to evaluate the frequency of thrombus formation on double-lumen hemodialysis catheters and its significance for catheter malfunction. In 14 patients who had a double-lumen hemodialysis catheter for temporary or long-term vascular access, IVUS of the catheter and the mediastinal vein stems was performed. Mean indwelling duration at the time of the ultrasound investigation was 101 days (range. 3 to 730 days; median, 58 days). Four patients had catheter-related thrombotic complications: IVUS failed to detect an intracatheter thrombus in one case; a catheter thrombus and superior vena cava stenosis were found in a catheter with normal function in one case; in one case with catheter malfunction, a combined catheter-mural thrombus was found; and in the remaining case, a catheter thrombus and a mural superior vena cava thrombus were found in a patient with normal catheter function and pulmonary emboli. Thus, two of 12 patients with well-functioning catheters (16%) had thrombotic complications demonstrated by IVUS, and one of two patients with catheter malfunction had thrombus identified by IVUS. It is concluded that thrombus formation is less likely in patients without signs of catheter malfunction.(ABSTRACT TRUNCATED AT 250 WORDS)