Side-hole Catheter Research Articles

Educational Exhibit Abstract No. 305 - Utility of customized trapdoor cecostomy tube for long-term internal biliary drainage in the setting of benign biliary strictures

Learning Objectives Introduce the technique of placement of customized cecostomy tubes (c-tubes) as an alternative to conventional biliary drains for long-term biliary drainage. Background Benign biliary strictures remain a frequent cause of morbidity in liver transplants requiring multiple percutaneous biliary interventions such as balloon cholangioplasty, long term locking loop biliary catheter placement, and biliary catheter upsizing. The complications of locking loop catheters include catheter dislodgment, kinking, and interference with daily activities. Clinical Findings/Procedure Details A 10.2F Cook Chait TrapdoorTM C-tube (Bloomington, Indiana) has been placed with technical success on 3 patients with split liver transplants complicated by benign central strictures. The first (age 17 yrs) over the last two years has had 9 exchanges with mean interval between exchanges of 10.8 weeks (range 7 - 14 wks.) The second (age 5 yrs) recently had the c-tube placed without complication. The third (age 21 mo) had the c-tube for 3 weeks. On follow up, the catheter was no longer required and removed. The tube has not fallen out in any case. The access of the biliary system does not differ. Prior to placement the c-tube must be molded using steam to temporarily undo the coils. There is no locking loop. The catheter is supported by the distal coils.The benefits include low external profile, stability from the increased coils in the bowel, and decreased excursion within the biliary tree. The low profile has been reported by parents to fit conveniently under clothing, limit the stigmata of chronic disease, prevent entanglement and pulling by the child. Limitations include the increased time of steaming (~2 min), tendency to accordion on placement, creation of proximal catheter side holes, and extra steps required in flushing. Conclusion and/or Teaching Points Technical differences in placing customized c-tube as opposed to conventional internal/external biliary drains for long-term internal biliary drainage are not substantial. However, there is a decreased potential of dislodgement and improved aesthetics for the child and family. Given initial positive experience in the pediatric population, the technique may prove beneficial in adults.

2:26 PM Abstract No. 203 - Intraperitoneal chemotherapy catheter placement using percutaneous technique in patients without ascites

Purpose The addition of intraperitoneal chemotherapy (IP) to intravenous chemotherapy (IV) for the treatment of advanced ovarian cancer has demonstrated improved survival in comparison to IV chemotherapy alone. Traditionally, IP catheters where placed surgically with reported complications in 9.6% to 34% of patients. We seek to review the outcomes of using a percutaneous IP catheter placement technique in patients without ascites. Materials and Methods IP catheter placement was carried out while undergoing conscious sedation. Ultrasound guidance was initially used to access the peritoneal cavity over the right lobe of the liver. A 5 Fr catheter was placed into the IP cavity and the abdomen was distended with carbon dioxide. Under fluoroscopic guidance, the abdominal right upper quadrant was accessed at the site of the accumulation of gas, thus avoiding potential injury to bowel. A 14.3 Fr multi side-holed catheter was then placed into the pelvis with the port reservoir tunneled over the anterior chest wall subcutaneous tissues. We retrospectively reviewed all patients who received percutaneous IP catheter placement from 12/2008 through 8/2012. Results Twenty-three patients underwent percutaneous IP catheter placement. One patient (4.3%) had an intra-procedural complication although the catheter was ultimately placed. Fourteen patients (60.8%) completed IP chemotherapy. Four patients (17.4%) continue to receive IP chemotherapy. One catheter (4.3%) was removed due to a catheter related infection. Four patients (17.3%) had their catheters removed for reasons unrelated to the IP catheter: two due to side effects from chemotherapy, one due to sepsis caused by perforated diverticulitis that was felt to be unrelated to the IP catheter by the surgeon who preformed the exploratory laparotomy, and the last due to sepsis from an infected IV catheter which did not involve the IP catheter. Conclusion Percutaneous placement of IP catheters in patients without ascites using carbon dioxide insufflation has a high technical success rate with low risk of catheter-related complications. This procedure offers a viable alternative to traditional surgical placement.

Side-hole Catheter Placement for Hepatic Arterial Infusion Chemotherapy in Technically Difficult Cases

Side-hole Catheter Placement for Hepatic Arterial Infusion Chemotherapy in Technically Difficult Cases

Successful Thrombolysis of Occluded Inferior Vena Cava Filter with IVC Syndrome.

Thrombosis of Inferior Vena Cava (IVC) following filter insertion can occur in up to 30% of the cases. The optimal management of such cases is unknown. We describe a simple and less expensive method of achieving successful recanalization of the IVC in a 40 year old hypertensive man who developed recurrent pulmonary embolism after his orthopedic treatment. An IVC filter was inserted, which developed extensive thrombosis of the whole IVC and venous system of the lower limbs. Catheter directed thrombolysis using a multiple side-hole multipurpose catheter and balloon angioplasty was carried out in order to "crush and lyse" the IVC thrombi.

Safety and efficacy of catheter directed thrombolysis in children with deep venous thrombosis

Safety and efficacy of catheter directed thrombolysis in children with deep venous thrombosis

Hemodynamics in the Cardiac Catheterization Laboratory of the 21st Century

There has been a striking evolution in the role of the cardiac catheterization laboratory over the past decades.1 In the 1950s and 1960s, hemodynamic assessment in the cardiac catheterization laboratory was essential for understanding the physiology and pathophysiology of patients with cardiovascular diseases. With the development of surgical interventions to treat patients with valvular and congenital heart disease, it became necessary for the cardiac catheterization laboratory to provide an accurate hemodynamic assessment, laying out a therapeutic road map. Nearly all patients who had open heart surgery underwent a complete hemodynamic catheterization before surgery. In the 1980s and 1990s, the evolution of 2-dimensional echocardiography and Doppler echocardiography provided an alternative noninvasive approach for the assessment of both cardiac anatomy and hemodynamics in patients with structural heart disease.2 By measuring blood flow velocities noninvasively, Doppler echocardiography was able to provide information on volumetric flow, intracardiac pressures, pressure gradients, and valve areas, as well as diastolic filling of the heart. Furthermore, noninvasive studies could be repeated easily, allowing the practitioner to follow the progress of his/her patient's condition longitudinally. At the same time, there was growing emphasis on coronary angiography for defining epicardial coronary disease with the subsequent development of interventional approaches for coronary disease with catheter-based therapies. As the major focus in the catheterization laboratory shifted to the diagnosis and treatment of the patient with acute and chronic coronary artery disease, the hemodynamic assessment of patients with structural heart disease was left to the noninvasive echocardiographic laboratory. As a consequence, many cardiac catheterization laboratories provided neither the training nor the expertise to assess hemodynamics properly. However, the advent of procedures such as balloon valvotomy, percutaneous valve implantation, and septal ablation has revived interest in structural heart disease and provided the invasive cardiologist with an armamentarium to treat patients who previously …

A novel endoesophageal magnetic device to prevent gastroesophageal reflux

Endoscopic methods to prevent gastroesophageal reflux (GER) show scarce effectiveness and may narrow the esophageal lumen more or less stiffly, sometimes impairing bolus transit and leading to dysphagia. The aim of this study was to demonstrate the possibility of reinforcing lower esophageal sphincter (LES) tone by implanting endoluminally a magnetic device. The device consists of two small magnetic plaques to be implanted in the submucosa close to LES with opposite polarities facing so that they attract one other, closing the esophageal lumen. The magnets were implanted by means of a special endoluminal device in five esophageal-gastric ex vivo specimens taken from swine. Variation in endoluminal pressure at the LES level was measured by means of slow pull-through of a thin side-hole manometric catheter in each specimen, before and after insertion of the magnets. The new high-pressure zone exhibited a length of about 2 cm and a pressure of 14.2+/-1.27 mmHg [mean +/- standard deviation (SD)], significantly (p<0.001) higher than that measured before insertion of the magnetic valve (1.5+/-0.26 mmHg). The present research demonstrates that it is possible to create at the LES level a dynamic closure of a value considered sufficient to prevent GER, by implanting in the esophageal submucosa of anatomical specimens a magnetic device by means of a special endoluminal probe. Once effectiveness and tolerability of magnets covered by a biocompatible sheath have been demonstrated in vivo, this device could become a simple and effective nonsurgical solution to GER.

Side-Hole Catheter Placement for Hepatic Arterial Infusion Chemotherapy in Patients with Liver Metastases from Colorectal Cancer: Long-Term Treatment and Survival Benefit

The objective of this study was to evaluate retrospectively correlations between catheter placement methods and treatment outcomes of patients treated with hepatic arterial infusion chemotherapy for unresectable liver metastases from colorectal cancer. This study involved 135 patients with liver metastases from colorectal cancer who underwent intrahepatic chemotherapy using catheter-port systems. Complications, treatment discontinuation, hepatic progression, and survival of patients treated with each method were evaluated retrospectively using the Kaplan-Meier method. Conventional 5-French end-hole catheter placement (n = 10) was compared with three side-hole catheter placement methods: 5-French side-hole catheter placement with a fixed catheter tip (original fixed catheter tip method, n = 77); long tapered side-hole catheter placement using a fixed catheter tip method (modified fixed catheter tip method, n = 24); and long tapered side-hole catheter inserted distally in the hepatic artery (long tapered catheter placement method, n = 24). The following treatment outcomes were significantly better for patients treated using the original or modified fixed catheter tip or long tapered catheter placement method than for those treated using the conventional method, respectively: hepatic arterial patency (1 year: 76.3%, 95.0%, and 94.4% vs 38.9%; p = 0.0014, 0.0007, and 0.0006), catheter stability (1 year: 96.7%, 95.5%, and 95.2% vs 42.9%; p < 0.0001, p = 0.0003, and p = 0.0009), time to treatment discontinuation (medians: 11.7, 14.4, and 12.4 vs 3.2 months; p < 0.0001, 0.0002, and 0.0019), time to hepatic progression (medians: 14.7, 15.7, and 15.8 vs 5.5 months; p = 0.0049, 0.0141, and 0.0004), and overall survival (medians: 21.1, 22.5, and 23.1 vs 13.1 months; p = 0.0146, 0.0036, and 0.0017). Compared with the conventional method, side-hole catheter placement methods allowed long-term intrahepatic chemotherapy and resulted in improved survival.

Alfimeprase

Alfimeprase

An Uncommon Problem with the Use of an Ultrasound Guided Interscalene Catheter in a Five-Year-Old Child

Purpose of the study: We wish to report the case of a 5-year-old boy who had an interscalene catheter placed under ultrasound guidance. There is low level evidence to support the use of ultrasound when performing peripheral nerve blocks in adults and children. We will discuss the technique and an unusual complication with the catheter. Methods: A 5-year-old, 20 kilogram, ASA I child was scheduled for a humeral osteotomy. Following induction of general anaesthesia an interscalene catheter was placed using both a nerve stimulator and ultrasound guidance. The catheter threaded easily and a dose of 7 ml 0.5% Ropivicaine was injected down the catheter, followed by another 3 ml at the end of surgery. Results: The child had a successful sensory block and required only simple analgesia (oral paracetamol and ibuprofen) post-operatively. Of interest we were unable to elicit appropriate muscle twitches with the nerve stimulator despite good visualization of the brachial plexus and needle with the ultrasound. In addition, after a short period post-operatively we were unable to inject local anaesthetic down the catheter and it was subsequently removed. Following removal we found blood clot occluding all but one of the catheter side holes. Conclusions: Ultrasound guidance was used to place an interscalene catheter in a 5-year-old—to date, the smallest child having this procedure in our hospital. Although the block was successful the catheter became occluded by clot. We have been unable to find other reports of this problem in the literature. Using ultrasound has the potential to reduce the risk of complications when placing interscalene catheters, particularly in children. Furthermore, this case illustrates that the use of a nerve stimulator may not guarantee adequate localization of the nerves during neural blockade.

A simple catheter‐vessel model for MR assessment of drug distribution in arteries and optimization of catheter design for intraarterial infusion therapy

To investigate the efficacy of a new catheter-vessel model for MRI to evaluate drug distribution and to optimize catheter design for intraarterial infusion therapy The model consisted of a hepatic artery simulant tube through which blood simulant water flowed continuously and a water cistern. Catheters were inserted into the tube and a gadolinium contrast medium was injected at rates suitable for angiographic or computed tomographic evaluation and commensurate with the clinical drug infusion rate. Axial images of the tube were obtained with a 0.2-T scanner and gradient echo technique. Preliminary studies and catheter tests were conducted. The points at which drug and water were completely mixed were defined as the site with uniform enhancement nearest the catheter tip. Flip angle and gadolinium concentrations were optimized at 90 degrees, and at 62.5 and 500 mM for the high and low infusion rates, respectively. Drug distribution near the catheter tips was clearly visualized. The drug was mixed in shorter distances via the slit side-hole than the end- or side-hole catheters, and the smaller diametrical than the larger at either rate. This model appeared to be effective for evaluation of drug distribution and optimization of catheter design.

Placement of a Long Tapered Side-Hole Catheter in the Hepatic Artery: Technical Advantages, Catheter Stability, and Arterial Patency

The purpose of this study was to evaluate the technical advantages, safety, and efficacy of placing a catheter distally in the hepatic artery using a long tapered side-hole catheter with an implantable port for hepatic arterial infusion chemotherapy. Fifty patients with unresectable malignant liver tumors underwent radiologic implantation of catheter-port systems using the long tapered catheter placement method. A 2.7-French distal shaft of the catheter was inserted distally in the hepatic artery with its side hole located proximally, and a 5-French proximal shaft was placed in the aorta; the catheter tip was not fixed. Technical success, complications including catheter stability and hepatic artery patency, and tumor response were assessed and compared with the following two historical controls: 35 patients with a 5-French catheter inserted simply in the hepatic artery (conventional method), and 131 patients with a 5-French catheter, the tip of which was fixed in the gastroduodenal artery (the fixed-catheter-tip method). The technical success rate using the long tapered catheter placement method was 92% (46/50 patients), whereas the feasibility of the fixed-catheter-tip method was confined to 79% of historical controls (131/166 patients). Among patients in whom the gastroduodenal artery was present, a decreased frequency of gastroduodenal artery embolization was seen using the long tapered catheter placement method (39%; 17/44 patients) compared with the conventional method (p = 0.0112) and the fixed-catheter-tip method (p < 0.0001). Cumulative stability rates of the catheter (6 months, 94.9%; 1 year, 94.9%; 2 years, 86.2%) and cumulative patency rates of the hepatic artery (6 months, 89.9%; 1 year, 89.9%; 2 years, 83.5%) were significantly higher using the long tapered catheter placement method than using the conventional method (p = 0.0208 and p = 0.0066, respectively) but were similar to those using the fixed-catheter-tip method. The time of hepatic tumor progression was significantly longer using the long tapered catheter placement method than using the conventional method (p = 0.0299) but was comparable to the time using the fixed-catheter-tip method. The long tapered catheter placement method should find wider application in hepatic arterial infusion chemotherapy because it is useful in preventing catheter dislodgment and hepatic artery occlusion.

Comparison of side hole versus non side hole high flow hemodialysis catheters

Current literature suggests that side holes may be detrimental to dialysis catheter performance. Today, these catheters are primarily available with side holes. The purpose of this study was to compare flow rates, infection rate, and survival of side hole vs. non side hole hemodialysis catheters. Over a 16-month period patients were arbitrarily assigned to either a 14.5 F MAHURKAR MAXID cuffed dual lumen tunneled catheter with side holes or a 14.5 F MAHURKAR MAXID cuffed dual lumen tunneled catheter without side holes ("non side hole catheters"). We performed a retrospective analysis of catheter flow rates, patency, catheter survival, and catheter-related infections. Information was gathered for the life of the catheter or up to 28 weeks. A total of 54 patients were enrolled in the study. Thirty-seven of 54 (68%) patients received a catheter with side holes for a total of 3,930 catheter days and 17/54 (32%) received a similar catheter without side holes for a total of 2,188 catheter days. Catheter infection necessitating removal of the catheter occurred in 10/37 catheters with side holes and 1/17 without side holes. Infection rates per 1,000 catheter days were 2.545 with side holes and 0.254 without side holes (p<0.001). Slightly improved catheter survival (p<0.05) was recorded with the non side hole catheters. No insertion complication (e.g., air embolization, bleeding, or kinking) occurred with either catheter. One catheter without side holes had to be repositioned 5 days after insertion because of poor flows. No significant difference was recorded in mean blood flow rates between the catheters. Results indicate reduced catheter infection rate in hemodialysis patients with the use of non side hole dual lumen tunneled cuffed catheters.

IMPACT OF SIDE HOLES AND TIP LOCATION ON SHEAR STRESS DISTRIBUTION AND ACCESS RECIRCULATION IN A CENTRAL VENOUS CATHETER

Shear stresses and access recirculation (AR%) are two major indicators of the hemodynamic performance of a hemodialysis catheter. In this study the impact of the presence and size of catheter side holes (SH) and the effect of the location of the tip on these performance parameters are quantified using 3D computational fluid dynamics simulations (Fluent 6). The catheter under study is of a shot-gun type with two cylindrical lumens: a blood withdrawing arterial lumen (AL) with two SH and a venous lumen without SH. The catheter is either inserted in a cylinder representing the Vena Cava (tip in vein) or with its tip in an anatomically realistic 3D model of the right atrium and the caval veins (reconstructed from The Visible Human Project, NLM-NIH). The shear stress distribution is assessed for SH open, closed or reduced in size (diameter/2). AR% is calculated at different caval vein and catheter flow rates with normal or reversed catheter connections. In both models, shear stress is elevated at the AL tip wall (closed SH) or near the SH inlet and outlet (open SH). Opening or closing the SH does not affect the range of shear stress (50–200Pa) but more elevated shear stresses appear when SH are reduced. AR% with normal connections is nil for both tip locations but differs between the models when connections are reversed. Moreover, a decreased catheter flow rate causes an increased AR% when the tip is in the vein, compared to a decreased AR% when the tip is in the right atrium. We conclude that the presented models are useful to study impact of flows on AR%.

Hepatic arterial cannulation using the side holed catheter

Hepatic arterial infusion chemotherapy (HAIC) has been recognized as one of the effective treatments for patients with hepatic metastatic tumor. However it is difficult to perform HAIC in the long term without complications. This report describes the laparotomic approach using the side holed catheter, which is a novel method of implanting a catheter-port system. We designed a new anti-thrombotic catheter for HAIC. This catheter is tapered from 5F (diameter of shaft) to 3.3F (diameter at tip), and a side hole is opened 7 cm from the tip of catheter. This catheter is inserted from the gastroduodenal artery to the common hepatic artery (CHA), and the tip is put in the aorta or in the splenic artery. The side hole is adjusted distal to the CHA. In our surgical department, our new catheter was inserted in four patients at the time of their abdominal surgery. The cannulation was performed successfully in all patients. In two of them, HAIC was finished without problems at 6 months after starting, and two were still treated by HAIC at 9 and 8 months after starting. Initial results from a study of a new method of implanting a catheter-port system in the hepatic artery using the new tapering side hole catheter suggest that this method may enable operators to avoid complicated selective coiling and may lower the incidence of hepatic artery occlusion in patients receiving long-term HAIC.

Radiologic Placement of Side-hole Catheter with Tip Fixation for Hepatic Arterial Infusion Chemotherapy

To investigate the technical outcome of radiologic catheter placement with use of a side-hole catheter with distal fixation for hepatic arterial infusion chemotherapy. Between January 1993 and September 1999, 426 patients were referred to our department to undergo intraarterial infusion chemotherapy for unresectable malignant liver tumors. A subclavian artery was exposed under local anesthesia and a catheter was inserted. After inserting the tip of the side-hole catheter into the gastroduodenal artery, splenic artery, or peripheral branch of the hepatic artery, the catheter tip was fixed to the vessel with use of coils and a mixture of n-butyl cyanoacrylate (NBCA) and iodized oil. The proximal end of the catheter was connected to an implanted port, and the port system was embedded subcutaneously. Placement was successful in 425 of 426 patients (99.8%) in a mean time of 76 minutes. Catheter dislodgement was noted in 12 patients (2.8%). Cumulative patency rates of the hepatic artery calculated according to the Kaplan-Meier method for the entire group were 91.0%, 81.4%, and 58.1% at 6 months and 1 and 2 years, respectively. Complications related to catheter placement were observed in nine cases and included dysfunction of the implanted system (n = 3), significant bleeding around the implanted port (n = 2), improper infusion of NBCA and iodized oil (n = 2), and cerebral infarction (n = 2). Radiologic catheter placement via a subclavian artery with side-hole catheter placement with distal fixation for hepatic arterial infusion chemotherapy is a highly successful procedure with a reduced risk of catheter dislodgment and arterial occlusion.

Coronary Pulsed-Spray: Accelerated Pharmacomechanical Intravascular Thrombolysis in Acute Coronary Events Followed by Immediate Endovascular Therapy

Coronary thrombolysis and percutaneous coronary angioplasty (PTCA) have improved the short— and long-term prognosis in patients with acute coronary events. This study proposes a rapid approach to lyse the thrombotic material present in the ischemic related vessel (IRV) and immediately apply the most appropriate therapy based on the underlying anatomy. Fifty patients, 24 with myocardial infarction (MI) and 26 with unstable angina (UA), were treated. Once the IRV was identified, a 15 multiple side-hole infusion catheter was placed across the clot matrix and 25,000 units of urokinase were administered forcefully every 30 seconds in pulses of 1 mL, using a 1-mL syringe to obtain a spray effect until a total of 1,000,000 units were completed in 20 minutes. Immediate results after the pulsed-spray thrombolysis (PST): The % stenosis decreased from 96 ± 9 to 49 ± 37 and the flow increased from TIMI 0.06 ± 0.02 to TIMI 2.7 ± 0.6, P < 0.001. Therapeutic procedures immediately after the PST: 30 patients were treated with percutaneous transluminal coronary angioplasty (PTCA) followed by stent deployment, 8 with conventional PTCA, 10 received medical therapy, and 1 underwent elective surgical revascularization. Two patients had minor self-limited gingival bleeding. One patient had a groin hematoma, and another patient developed a right femoral artery pseudoaneurysm, corrected surgically. One patient with unstable angina died with no-reflow phenomenon in the circumflex coronary artery. Twenty four patients (48%) have been followed up (11 ± 3.6 months), all in functional Class I–II. Eight (16%) who underwent repeat coronary angiography 4 ± 2.2 months post-PST, had TIMI 3 flow in the IVR. PST applied to the coronary circulation in acute ischemic events is a method able to lyse the thrombotic material associated with the complicated plaque. This approach allows better selection of an immediate endovascular therapy for each patient based on the underlying anatomy and results in a shorter hospital stay. (J Interven Cardiol 2000; 13:19–26)

Hepatic arterial infusion chemotherapy using percutaneous catheter placement with an implantable port: Assessment of factors affecting patency of the hepatic artery

OBJECTIVE: To assess the factors affecting patency of the hepatic artery during hepatic arterial infusion chemotherapy (HAIC) with an implantable port system inserted percutaneously. PATIENTS AND METHODS: Ninety patients with malignant hepatic tumours were given HAIC using percutaneous catheter placement. An end-hole catheter was inserted into the hepatic artery (conventional method) in 41 patients. An end-closed and side-hole catheter was used in 49 patients, in which the catheter tip was fixed in the gastroduodenal artery and the side hole was placed in the common hepatic artery (fixed catheter-tip method). The patency of the hepatic artery was evaluated with computed tomography (CT) arteriography using the implantable port system and angiography. Then, the factors affecting hepatic arterial patency were analysed. RESULTS: Hepatic arterial occlusion was observed in 15 patients (17%). The overall patency of the hepatic artery was 86.9%, 78.4% and 51.5% at 6 months, 1 year and 2 years, respectively. The patency rate of the hepatic artery was significantly higher in patients with catheter placement using fixed catheter-tip method than those using conventional method ( P = 0.01), and in patients without transcatheter arterial chemoembolization (TACE) prior to catheter placement than those with prior TACE ( P = 0.01). When the variables affecting patency of the hepatic artery were studied together by multivariate analyses, the important factors were the method of catheter placement and the presence or absence of prior TACE. CONCLUSION: We consider that it is important for long-term patency of the hepatic artery during HAIC to use fixed catheter-tip method for percutaneous catheter placement instead of conventional method, and to select patients without prior TACE.

Umbilical artery catheters in the newborn: effects of catheter design (end vs side hole).

This section is under preparation and will be included in the next issue. To determine whether the design of an umbilical arterial catheter influences the frequency of ischemic events, aortic thrombosis, intraventricular hemorrhage, mortality or necrotising enterocolitis in newborn infants. Randomized and quasi randomized controlled trials of umbilical catheterization use were obtained from the following sources: 1. Effective Care of the Newborn Infant, edited by JC Sinclair and MB Bracken. 2. Medline Search using Melvyl Medline Plus and the keyword headings 'Umbilic#', 'Catheter#' and subject heading 'Infant, Newborn' 3. Search of personal data files Randomized trials in newborn infants of any birthweight or gestation. Comparison of end hole catheters with side hole catheters. Clinically important end points such as ischemic events or aortic thrombosis. There appears to be only a single trial which has addressed this issue (Wesstrom 1979). End hole catheters are associated with a much decreased risk of aortic thrombosis compared to side hole catheters. RR = 0.27 (95% CI 0.11, 0.67) Side hole catheters should be avoided for umbilical arterial catheterisation in the newborn.

Study of catheter designs and drug mixing processes using 2D steady numerical simulations.

The effectiveness of substance delivery through catheters is an important issue in interventional radiology, especially for infusion therapies where the pharmacokinetic advantage of local intra-arterial drug administration has been firmly established. In principle, the procedure is used to provide appropriate local concentrations while maintaining low systemic values so as to minimise the global effect and toxicity of the intervention. However, poor drug mixing may produce excessive local concentrations potentially damaging for the surrounding tissues and may lead to unsuccessful therapies. These phenomena have been observed in the infusion therapies of liver cancers through the hepatic artery and with brain tumour therapies through the carotid artery. Many aspects of the drug delivery methodology have been explored in order to determine the infusion conditions that would provide optimal mixing: the catheter tip design is considered one of the most important characteristics to be investigated for this purpose. Interestingly, it turns out that angiographic procedures could also benefit from this, because better mixing properties are associated with designs that provide potentially less harmful flow conditions such as jets, whipping and recoil of the catheter on the vascular wall. A 2D steady numerical model is proposed, to simulate the main physical processes occurring during catheter substance infusion: blood dynamics is taken into account with the Navier-Stokes equations and substance dispersion by the flowing blood with the advection-diffusion equation. The model is used to evaluate mixing properties of certain catheter designs in different flow conditions. In particular, two types of side hole catheter are compared in the context of water bath injection and in the context of vessel injection. The simulations suggest that the improved mixing reported with water bath experiments would not be maintained in the clinical context of arterial circulation.