Intrapulmonal dislocation of a totally implantable venous access device

BACKGROUND: Totally implantable venous access devices are widely used for infusion of chemotherapy or parenteral nutrition. Device associated complications include technical operative problems, infections, paravasal infusions and catheter or punction chamber dislocation. CASE PRESENTATION: We present the case of a 49-year-old patient with the rare complication of a intrapulmonal catheter dislocation of a totally implantable venous access system. Treosulfane for chemotherapy of metastatic breast cancer was infused via the catheter causing instant coughing and dyspnoea which lead to the diagnosis of catheter dislocation. The intrapulmonal part of the catheter was removed under thoracoscopic control without further complications. CONCLUSION: Intrapulmonal catheter dislocation is a rare complication of a totally implantable venous access device which can not be avoided by any prophylactic measures. Therefore, the infusion system should be tested before each use and each new symptom, even when not obviously related to the catheter should be carefully documented and evaluated by expert physicians to avoid severe catheter-associated complications.     

The YUMIKO catheter: a useful tool for angiography of the right internal mammary artery via a right brachial approach

The YUMIKO catheter (Goodman, Nagoya, Japan) was recently developed for a left internal mammary artery (IMA) angiography with a right radial or brachial approach. The present authors experienced an interesting case where the YUMIKO catheter was useful for a right IMA angiography via a right brachial artery. A 53-year-old man with bilateral IMA grafts underwent follow-up coronary angiography via a right brachial artery. Native coronary artery and left IMA angiography were performed without difficulty using the Judkins Right and Left and YUMIKO catheters. Angiography of the right IMA was attempted with the Judkins Right catheter and IMA catheter, resulting in a nonselective angiogram with poor imaging. The YUMIKO catheter, however, enabled smooth cannulation to the right IMA and provided good images of the selective right IMA angiography.     

Prevention of catheter-related infections by a new, catheter-restricted antibiotic filling technique

Catheter-related infections pose a hazard to both humans and laboratory animals. The aim of this study was to develop a technique preventing bacterial colonization of intravascular catheters. In 27 dogs a total of 70 catheters were implanted. On an average catheters were used for 207 days. Three protocols were compared: (1) flushing the catheters with a heparinized solution; (2) filling only the catheter lumen with alpha-chymotrypsin solution (225 units/ml); (3) filling only the catheter lumen with a solution containing a mixture of the aminoglycoside antibiotic gentamicin (20 mg/ml) and chymotrypsin (225 units/ml). Catheter fillings were always withdrawn before catheter use. Catheter exit sites were all treated with povidone iodine ointment once a day. Body temperatures and weights were recorded, bacteriological and electron microscopical examinations of catheters performed. Without gentamicin filling all catheters were colonized after a few weeks. The dogs showed clinical signs of chronic bacteraemia. Gentamicin filling eradicated colonization. No further bacteraemia was observed. We conclude that filling only the catheter lumen with a concentrated solution of chymotrypsin and gentamicin, combined with measures to prevent infections via the subcutaneous catheter tunnel, is an effective and safe technique to prevent catheter-related infections.     

The analysis of glucose kinetics using a single jugular catheter in awake rats

The rates of glucose production and utilization can be estimated by a primed-constant infusion technique using separate catheters for the infusion of radiolabelled glucose and periodic blood withdrawal. In rats, a carotid artery catheter is most often combined with a jugular or femoral venous catheter in such studies. We presently describe a method which utilizes a single jugular catheter for both infusion and sampling in the awake rat. This method is directly compared with simultaneous carotid artery sampling during both the dynamic steady state and a nonsteady state induced by a constant infusion of insulin. Our results demonstrate the validity of a single vein design for the analysis of glucose kinetics in either state. Rapid sampling and complete flushing prevent disruption of infusate equilibrium and sample contamination respectively. This single catheter method requires less technical skill for placement, reduces surgical intervention and enhances the comfort of the awake rat.     

Percutenous catheter ablation of the accessory pathway in a patient with wolff-Parkinson-white syndrome associated with familial atrial fibrillation

Percutenous catheter ablation of the accessory pathway in Wolff-Parkinson-White syndrome is a highly successful mode of therapy. Sudden cardiac arrest survivors associated with WPW syndrome should undergo radiofrequency catheter ablation. WPW syndrome associated with familial atrial fibrillation is a very rare condition. Herein, we describe a case who presented with sudden cardiac arrest secondary to WPW syndrome and familial atrial fibrillation and treated via radiofrequency catheter ablation.     

Lasso technique for retrieving a broken, dislocated port-a-cath fragment

A 52-year-old woman suffering from breast cancer had a port-a-cath implanted to administer chemotherapy. A port-a-cath (a portmanteau of portal and catheter) consists of a reservoir compartment (the portal) which has a silicone bubble for needle insertion (the septum) mounted to the catheter. Six and a half months after implantation, she complained of palpitations. An ECG showed sinus rhythm with premature atrial complexes. An X-ray showed dislocation of the distal tip of the catheter with migration into the right atrium (RA) and right ventricle (RV).     

Determination of cardiac contractility in awake unsedated mice with a fluid-filled catheter

Today, cardiac contractility in mice is exclusively measured under anesthesia or in sedated animals because the catheters available are too rigid to be used in awake mice. We therefore developed a new catheter (Pebax 03) to measure cardiac contractility in conscious mice. In this study, we evaluated the accuracy and utility of this new catheter for assessment of cardiac contractility in anesthetized and conscious mice. With the use of a balloon-pop test, the Pebax catheter with an inner diameter of 0.3 mm was found to exhibit a high natural frequency, a low damping coefficient, and a flat frequency of up to 50.5 +/- 0.6 Hz. Under anesthesia (0.5% or 1.0% halothane), no difference was found in heart rate (HR), left ventricular (LV) systolic pressure (LVSP), the maximum rates of LV pressure rise and fall (LV dP/dt(max) and LV dP/dt(min), respectively), ejection time (ET), and isovolumic relaxation time constant (tau) when measured with either the 1.4-Fr Millar or Pebax 03 catheter. However, when HR, LVSP, LV dP/dt(max), and LV dP/dt(min) were recorded with the Pebax catheter in awake mice, values were significantly higher, and ET and tau were lower, than under anesthesia, suggesting a major impact of anesthesia on these parameters. The Pebax catheter was also used in a normotensive one-renin gene mouse model of cardiac hypertrophy induced by DOCA and salt. In this model, DOCA-salt induced a severe decrease in cardiac contractility in the absence of changes in blood pressure. These data demonstrate that cardiac contractility can be measured very accurately in conscious mice. This new device can be of great help in the investigation of cardiac function in normal and genetically engineered mice.     

External irrigation of a non-irrigated ablation catheter for effective AV node ablation during conduction system pacing

Ablation using non-irrigated catheter can lead to rapid rise in temperature of electrode tissue interface from tissue desiccation, steam and coagulum formation and this may limit power delivery and lesion size. We present a novel technique of external irrigation through the long sheath while using a non-irrigated ablation catheter during AV Node ablation and conduction system pacing. By bringing the long sheath closer to the tip of non-irrigated catheter and injecting cold normal saline allows cooling of electrode tissue interface leading to increase in power delivery resulting in a deeper lesion.     

Ventilation of a rat with a large-animal respirator

Rats were effectively ventilated with 100% O2 mixed with room air utilizing a modified tracheostomy tube and a Bird Mark 7 respirator to maintain arterial blood gases within normal limits. A 3-cm segment of rubber pilot tubing was attached to a 15-mm respiratory connector and a 3-cm piece of polyethylene catheter tubing was fitted snugly into the other end. The catheter was inserted and secured into the trachea of 250- to 500-g Sprague-Dawley rats with the adaptor hose of the respirator fitted onto the 15-mm connector following tracheostomy. Manometer and inspiratory flow rate controls of the respirator were set to their minimum operating position. Appropriate rate control adjustments were made when necessary as determined by arterial blood gas measurements. By use of the above ventilation system, adequate arterial blood gases of anesthesized rats can be maintained for greater than 3 h.     

A methodology for numerically analysing the hepatic artery haemodynamics during B-TACE: a proof of concept

Balloon-occluded transarterial chemoembolisation (B-TACE) is an intraarterial transcatheter treatment for liver cancer. In B-TACE, an artery-occluding microballoon catheter occludes an artery and promotes collateral circulation for drug delivery to tumours. This paper presents a methodology for analysing the haemodynamics during B-TACE, by combining zero-dimensional and three-dimensional modelling tools. As a proof of concept, we apply the methodology to a patient-specific hepatic artery geometry and analyse two catheter locations. Results show that the blood flow redistribution can be predicted in this proof-of-concept study, suggesting that this approach could potentially be used to optimise catheter location.     

Intramuscular pressures during exercise: an evaluation of a fiber optic transducer-tipped catheter system

The efficacy of a modified fibre optic transducer-tipped catheter system for measuring intramuscular pressures during exercise was determined. A microcapillary infusion technique using a catheter was employed as the standard of comparison due to its established dynamic properties. Pressures were measured in the tibialis anterior muscle of six healthy adults at rest before exercise, during isometric and concentric exercise, and at rest after exercise. The fibre optic system measured contraction pressures equal to the microcapillary infusion technique during all phases of the exercise protocols but recorded a lower relaxation pressure during isometric exercise and a lower rest pressure following 20 min of concentric exercise. Negative relaxation pressures were recorded by the fibre optic system for two subjects during continuous concentric exercise. It is hypothesized that a piston effect, due to the sliding of muscle fibres at the catheter tip following a contraction, rendered falsely low pressures during relaxation and that this artefact was reflected in the subsequent rest pressure following exercise. The larger volume (157 mm3) and area (3.49 mm2) of the fibre optic catheter in the muscle made it more prone to this effect than the conventional catheter (39 mm3 and 0.87 mm2, respectively). The fibre optic system may be preferred when recording the muscle contraction pressures during complex limb movements but should not be used when assessing the relaxation pressures or the pressure at rest following exercise.     

Description and validation of a novel technique to study the bacterial flora of the teat duct of ewes

We describe a new technique that may be used for studying the bacterial flora of the teat duct in live ewes, and we present evidence regarding its accuracy, safety and repeatability. A sterile, plastic, 20 G catheter is used for sampling. The catheter stylet is taken out and the plastic catheter cut with a sterile blade to a length of 2 mm. In order to ensure accurate and consistent cutting of the catheter at the desired length, a sterilized ruler is placed beside the catheter. The whole procedure is carried out under aseptic conditions, on sterilized surgical screens. Before sampling, a thorough disinfection with povidone iodine scrub solution of the teat apex and the lower (1 cm) part of the teat skin is carried out. The catheter is held by the investigator from the cannula hub; then, it is inserted into the teat, rolled around the internal teat wall, in order to sample the mucosa and then withdrawn. Material collected on the tip of the catheter is plated onto bacteriological media. The sensitivity of the technique compared to a method that detects the bacterial flora of the teat after slaughter of the animals (scratching of the teat mucosa by means of a scalpel blade) was 99.1% for field samples and 100% for experimental samples; specificity of the technique was 90.7 and 100%, respectively, kappa coefficient between results of the two methods was 0.9045. The safety of the technique was assessed in an investigation, where ewes were repeatedly (eight times) sampled by means of this technique, throughout their lactation; in no case was clinical or subclinical mastitis recorded. Finally, the repeatability of the method was assessed in 37 paired samples, obtained 30–40 min apart; a 100% match was recorded between bacteriological results of the two samplings of each pair. We conclude that the method can be useful in research studies, in order to obtain information regarding bacterial ecology and dynamics inside the teat of ewes.     

Flow in a catheterized curved artery with stenosis

The fluid mechanics of blood flow in a catheterized curved artery with stenosis is studied through a mathematical analysis. Blood is modelled as an incompressible Newtonian fluid and the flow is assumed to be steady and laminar. An approximate analytic solution to the problem is obtained through a double series perturbation analysis for the case of small curvature and mild stenosis. The effect of catheterization on various physiologically important flow characteristics (i.e. the pressure drop, impedance and the wall shear stress) is studied for different values of the catheter size and Reynolds number of the flow. It is found that all these flow characteristics vary markedly across a stenotic lesion. Also, increase in the catheter size leads to a considerable increase in their magnitudes. These results are used to obtain the estimates of increased pressure drop across an arterial stenosis when a catheter is inserted into it. Our calculations, based on the geometry and flow conditions existing in coronary arteries, suggest that, in the presence of curvature and stenosis, and depending on the value of k (ratio of catheter size to vessel size) ranging from 0.1 to 0.4, the pressure drop increases by a factor ranging from 1.60 to 5.16. But, in the absence of curvature and stenosis, with the same range of catheter size, this increased factor is about 1.74-4.89. These estimates for the increased pressure drop can be used to correct the error involved in the measured pressure gradients using catheters. The combined effects of stenosis and curvature on flow characteristics are also studied in detail. It is found that the effect of stenosis is more dominant than that of the curvature. Due to the combined effect of stenosis, curvature and catheterization, the secondary streamlines are modified in a cross-sectional plane. The insertion of a catheter into the artery leads to the formation of increased number of secondary vortices.     

A procedure to secure a jugular vein catheter system onto the neck of the hamster

We describe a procedure to secure a jugular vein catheter system at the dorsal nape of the neck in the hamster. An 8-cm piece of silicone tubing is connected with a 2.6 cm L-shaped metal tubing which is embedded in prosthetic material. The prosthetic material is placed underneath the neck skin of the hamster and keeps the metal end of the catheter system in a sturdy, upright position.     

In vitro simulations of embryo transfer in a laboratory model of the uterus

Embryo transfer (ET) is the final manual intervention during which the newly formed embryo is placed within the uterus by a transcervical catheter. The loading of the syringe-catheter complex with the transferred volume consists of the transfer media (which contains the embryos) separated by air spaces on both sides. The dynamics involved in injecting the syringe-catheter complex is not well understood nor has it been investigated to date. We developed an in vitro experimental setup for simulations of ET into a rigid transparent uterine model. The catheter was loaded in sequences of liquid and air as it is in the clinical setting. The transferred liquid was colored with a dye and its dispersion within the uterine cavity was recorded by a video camera. The results demonstrated, for the first time, the importance of having a gas phase in the catheter load. The resulting air bubbles within the uterus were carried upward towards the fundus by buoyant forces, thereby dragging behind them the transferred liquid which contained the embryos. This could be expected to substantially increase the probability for the embryos to be present near the fundal wall at the time window for implantation. There was also evidence of a dependency of the rate of injection upon the catheter load into the uterus: a low speed generated several air bubbles which led to more of the transferred liquid being carried towards the fundal end, thus possibly enhancing the potential for implantation.     

Pulsatile flow in a catheterised artery

A model is presented for the physiological problem of a catheter which is inserted in a femoral artery to measure the pressure gradient. As the catheter will modify the pressure distribution in the artery, the pressure gradient which would be recorded by a perfect pressure transducer attached to it would differ from that in the uncatheterised artery. To estimate the magnitude of this error, it is assumed that the rates of flow of blood through the catheterised and the uncatheterised artery are described by the same known periodic function of time.     

Central venous catheter infection with Bacillus pumilus in an immunocompetent child: a case report

Background

Bacillus organisms are common laboratory contaminants. The majority of Bacillus bacteraemias are transient and not clinically significant. Clinically significant infection due to Bacillus species is rare and mostly due to Bacillus cereus infections in immuno-compromised hosts.

Case presentation

We report a case of central venous catheter infection with Bacillus pumilus in an immunocompetent child with tufting enteropathy on long-term parenteral nutrition (PN). There were three episodes of central venous catheter infection with Bacillus pumilus in three months. Despite adequate and appropriate use of intravenous antibiotics, the infection failed to clear resulting in the need for removal of the catheter for complete cure.

Conclusion

Bacillus species can cause clinically significant central venous catheter infection, even in an immunocompetent host. Despite adequate antibiotic treatment, the central venous catheter may need removal for complete cure.     

Reduction of image artifacts in mice by bladder flushing with a novel double-lumen urethral catheter

In electron paramagnetic resonance imaging (EPRI), the accumulation of contrast agent in the bladder can create a very large source of signal, often far greater than that of the organ of interest. Mouse model images have become increasingly important in preclinical testing. To minimize bladder accumulation on mouse images, we developed a novel, minimally invasive, MRI/EPRI-friendly procedure for flushing a female mouse bladder. It is also applicable to other imaging techniques, for example, PET, SPECT, etc., where contrast agent accumulation in the bladder is also undesirable. A double-lumen urethral catheter was developed, using a standard IV catheter with a silicone tube extension, having a polyethylene tube threaded into the IV catheter. Flushing of the bladder provides a substantial reduction in artifacts, as shown in images of tumors in mice.     

Primary cutaneous mucormycosis. Report of a case in a HIV patient

Primary cutaneous mucormycosis is an unusual mycotic infection associated to immunosupression. We present a 34 year-old woman with HIV infection with a necrotic primary mucormycosis of the skin associated to a venous catheter. She was treated with amphotericin B and surgical debridement.     

Cryoablation of Anteroseptal Accessory Pathways with a His Bundle Electrogram on the Ablation Catheter

Background

Radiofrequency catheter ablations of anteroseptal (AS) accessory pathways (AP) in pediatric patients have higher incidence of atrioventricular (AV) block than other AP locations. We report our experience using cryoablation in pediatric patients where a His bundle electrogram was noted on the ablation catheter at the site of the successful ablation.

Methods and Results

We retrospectively reviewed all patients ≤21 years that underwent cryoablation for an AS AP from 2005 to 2012 at our institution (n=70). Patients with a His bundle electrogram noted on the cryoablation catheter at the location of the successful lesion were identified (n=6, 8.5%). All six patients had ventricular preexcitation. Median age of 15.9 years (7.2 - 18.2). AV nodal function was monitored during the cryoablation with intermittent rapid atrial pacing conducted through the AV node (n=2), with atrial extra-stimulus testing (n=2), or during orthodromic reentrant tachycardia (n=2). Acute success occurred in all patients. Two patients had early recurrence of AP conduction. Both patients underwent a second successful cryoablation, again with a His bundle electrogram on the cryoablation catheter. At a median follow-up of 13 months (3 to 37 months) there was no recurrence of accessory pathway conduction and AVN function was normal.

Conclusion

In a small number of pediatric patients with AS AP with a His bundle electrogram seen on the ablation catheter, the use of cryotherapy was safe and effective for elimination of AP conduction without impairment of AV nodal conduction.