Efficacy of thrombolytic therapy for occlusion of long-term catheters

Efficacy of Urokinase and Alteplase to Reopen Occluded Central Venous Catheters in Children

Objective:

To compare the efficacy of alteplase with that of urokinase (UK) in restoring the patency of occluded central venous catheters in children.

Study Design:

Retrospective case–control study at Hôpital Ste-Justine, a pediatric teaching hospital.

Results:

87 UK and 46 alteplase prescriptions were studied. Alteplase was effective in 93.2% of cases of occluded central venous catheters and UK in 54.5% of cases (p < 0.001).

Conclusions:

Alteplase was clearly superior to UK for restoring the patency of occluded central venous catheters in children. The study is limited by its retrospective design.

The effect of peripherally inserted central catheter (PICC) valve technology on catheter occlusion rates--the 'ELeCTRiC' study

PURPOSE

Peripherally Inserted Central Catheters (PICCs) are increasingly being used to provide short to medium-term central venous access. The current study was designed to test the hypothesis that PICC valve technology does not influence PICC occlusion rates.

METHODS

Intensive care unit (ICU) patients who required a PICC were randomized to one of three types of dual lumen PICC (open ended non-valved, Groshong valve, PASV valve). PICC occlusions were recorded and managed with a protocol that used urokinase.

RESULTS

A total of 102 patients were recruited to the study. The overall risk of occlusion per catheter was 35% (95% CI 26% to 44%). The overall rate of occlusion was 76 occlusions per 1000 catheter days (95% CI 61 to 95). Presence or type of valve did not significantly influence this rate (open-ended non-valved PICC 38% of catheters, 79 occlusions per 1000 catheter days; Groshong 38% of catheters, 60 occlusions per 1000 catheter days; PASV 27% of catheters, 99 occlusions per 1000 catheter days). The dose of urokinase required to treat PICC occlusions did not significantly differ between PICC types.

CONCLUSIONS

Valved PICCs do not appear to influence PICC occlusion rates.

[Indications, technique and complications of port implantation]

Implanted central venous access devices are becoming increasingly more important in oncology as an important tool for therapists and patients. As an intracorporeal system with reduced risk of infection compared to percutaneous tunnelled catheters they ensure a permanent and safe access to the central venous system. However, they can be associated with risks and sometimes severe complications which should not be underestimated so that planning and performance of the implantation require a high level of care and attention. Postoperative care and the correct allocation of all groups of persons involved in the therapy can reduce complication rates and are thus of prognostic relevance.

Catheter thrombosis and superior/inferior vena cava syndrome are rare complications of long term parenteral nutrition

The objective of this study was to determine the incidence of catheter thrombosis and superior/inferior vena cava (SVC IVC ) syndrome in a large population of patients receiving home total parenteral nutrition (TPN), using retrospective data collection and analysis. 527 patients including 138 children who were discharged on home TPN and followed in the UCLA home TPN program for a minimum of one week between April, 1973 and October, 1991. There was a total of 1154 years of patients follow-up, including 241 years in children. Fifty-seven patients (11%) developed 81 episodes of catheter thrombosis excluding SVC IVC syndrome with an incidence of 0.07 episodes per catheter year. The median catheter duration prior to thrombosis was 7 months. Twenty-one thromboses occured in children with an incidence of 0.09 per catheter year. Eleven percent of thrombotic episodes were associated with catheter sepsis. Thirty-nine percent of patients had a PTT less than control values. Twenty-two patients including 6 children developed SVC IVC syndrome with an incidence of 0.02 per catheter year. SVC IVC syndrome was not associated with catheter sepsis in any patient. Sixty-eight percent of patients had catheter thrombosis at some point prior to developing SVC IVC syndrome. It is concluded that catheter-related thrombotic events are rare complications of home TPN and are uncommonly associated with infection. However, we recommend warfarin anticoagulation following an initial thrombotic event, in the absence of catheter malposition, for all such patients as long as they maintain a central venous catheter.

Central venous port systems as an integral part of chemotherapy

BACKGROUND

Port systems are easy to implant on an in- or outpatient basis and provide reliable, long-lasting central venous access. They are used mainly for cancer patients.

METHODS

This article is based on a selective literature review, the guidelines of the German Society for Nutrition Medicine and of the European Society for Clinical Nutrition and Metabolism, and the recommendations of the German Society for Pediatric Oncology and Hematology.

RESULTS

In modern oncology, central venous port systems are increasingly replacing short-term and permanently tunneled central venous catheters. They are indicated for patients who need long-term intravenous treatment involving, e.g., the repeated administration of chemotherapeutic drugs, parenteral nutrition, transfusions, infusions, injections, and/or blood sample collection. Port systems can markedly alleviate the burden of intravenous therapy and thereby improve these patients' quality of life. The planning, preparation, and performance of port system implantation require meticulous attention to detail. The rate of implantation-associated complications is less than 2% in experienced hands; overall complication rates have been reported from 4.3% to as high as 46%. The proper postoperative use and care of the port system are of decisive importance to the outcome. Reported infection rates during port system use range from 0.8% to 7.5% in current clinical studies.

CONCLUSION

The treatment, follow-up care, and rehabilitation of cancer patients are interdisciplinary tasks. Optimal treatment and complication avoidance require a collaborative effort of all of the involved specialists-not just the physician implanting the port system, but also the oncologists, nutritionists, visiting nurses, and other home health care providers. Continuing medical education, too, plays a role in improving outcomes.

Access technique and its problems in parenteral nutrition - Guidelines on Parenteral Nutrition, Chapter 9

Catheter type, access technique, and the catheter position should be selected considering to the anticipated duration of PN aiming at the lowest complication risks (infectious and non-infectious). Long-term (>7-10 days) parenteral nutrition (PN) requires central venous access whereas for PN <3 weeks percutaneously inserted catheters and for PN >3 weeks subcutaneous tunnelled catheters or port systems are appropriate. CVC (central venous catheter) should be flushed with isotonic NaCl solution before and after PN application and during CVC occlusions. Strict indications are required for central venous access placement and the catheter should be removed as soon as possible if not required any more. Blood samples should not to be taken from the CVC. If catheter infection is suspected, peripheral blood-culture samples and culture samples from each catheter lumen should be taken simultaneously. Removal of the CVC should be carried out immediately if there are pronounced signs of local infection at the insertion site and/or clinical suspicion of catheter-induced sepsis. In case PN is indicated for a short period (max. 7-10 days), a peripheral venous access can be used if no hyperosmolar solutions (>800 mosm/L) or solutions with a high titration acidity or alkalinity are used. A peripheral venous catheter (PVC) can remain in situ for as long as it is clinically required unless there are signs of inflammation at the insertion site.

Thrombotic and infectious complications of central venous catheters in patients with hematological malignancies

Central venous catheters (CVCs) have considerably improved the management of patients with hematological malignancies, by facilitating chemotherapy, supportive therapy and blood sampling. Complications of insertion of CVCs include mechanical (arterial puncture, pneumothorax), thrombotic and infectious complications. CVC-related thrombosis and infections are frequently occurring complications and may cause significant morbidity in patients with hematological malignancies. CVC-related thrombosis and infections are related and can therefore not be seen as separate entities. The incidence of symptomatic CVC-related thrombosis had been reported to vary between 1.2 and 13.0% of patients with hematological malignancy. The incidence of CVC-related bloodstream infections varies between 0.0 and 20.8%. There is need for a specific approach regarding diagnosis and treatment of CVC-related thrombosis and infection with specific attention to the preservation of the catheter. Since data on CVC-related infections and thrombosis in hematological patients have been obtained mainly from retrospective studies of small sample size, prospective, randomized studies of prophylactic measures concerning CVC-related thrombosis and infection are warranted.

Lock method using sodium hydroxide solution to clear occluded central venous access devices

Occlusion of central venous access devices (CVADs) is not an uncommon problem duringlong-term parenteral nutrition. A number of techniques have been developed to deal with obstructed CVADs. This study investigated the effectiveness of the sodium hydroxide (NaOH) lock method for gradual CVAD occlusion. When a progressively declining flow was noticed, 0.1 N NaOH solution was injected into the CVAD and locked. Nineteen CVAD occlusions in 11 home parenteral nutrition patients were treated Sixteen of 19 trials cleared the occlusions, whereas 3 of 19 failed. One of the failures was due to a mechanical occlusion and the other two were able to be restored by using ethanol. There were no significant complications. The benefits of this method are: (1) a shorter treatment time and a lower dose than NaOH infusion therapy, (2) it does not require hospital admission and (3) it does not result in bursting of the catheter.

Lack of efficacy of twice-weekly urokinase in the prevention of complications associated with Hickman catheters: a multicentre randomised comparison of urokinase versus heparin

Hickman catheters (HC) are associated with complications, in particular infection, occlusion and thrombosis. We tested the hypothesis that regular flushing of catheters with urokinase would reduce the frequency of these complications. Patients who required a double-lumen HC for (1) bone marrow or peripheral blood progenitor cell transplantation or (2) intensive combination chemotherapy for haematological malignancies were randomised to receive twice-weekly flushes of either urokinase (5000 units) or heparin (50 units). HC-survival analysis was determined by Cox regression. 100 patients were enrolled (urokinase=52; heparin=48) and treated for a mean of 8.5 weeks. No significant difference was observed in the incidence of HC-associated septicaemic events, which occurred in 8/52 in the urokinase group and 9/48 in the heparin group (actuarial incidence 20% versus 25%, P=0.50). Similarly, there was no differences in the incidence of exit site infections (urokinase=27/52 and heparin=28/48, P=0.122); HC-septic thromboses (urokinase=2/52 and heparin=4/48, P=0.34); lumen occlusion (urokinase=30/52 and heparin=30/48, P=0.681); or venous thrombosis (urokinase=8/52 and heparin=6/48, P=0.726). Overall, a high incidence of HC-related complications was seen in both groups; 40/52 in the urokinase group and 40/48 in the heparin group (actuarial incidence 80% versus 90%, P=0.367). Despite this only 18% of HC required early removal due to complications (urokinase=8, heparin=10). There was no difference in the incidence of complications in patients undergoing transplantation (n=68) compared with chemotherapy alone (n=32). Patients with haematological malignancies were more likely to have HC-related infective complications (P=0.006), and patients with solid tumours more likely to have venous thrombosis (P=0.027). The cumulative incidence of HC-related complications in this prospective study was higher than in previously reported series. Urokinase did not appear effective in reducing the frequency of these complications.

Techniques in dosing for thrombolysis of occluded central venous catheters

Dosing of thrombolytic agents for restoration of flow to thrombotically occluded central venous catheters has been empiric. The lowest effective dose of any agent is not known. Given that none of the dosing regimens in current use has ever been found to be toxic, this is probably not a major clinical problem as long as the regimen is highly effective. Thrombolytic regimens differ in the type of drug, dose of drug, method of administration (injection versus prolonged infusion), and duration of administration. All of these variables are important in determining the efficacy, and possibly the toxicity, of a regimen. Active research is being conducted to determine the most effective ways of using the expanding number of thrombolytic medications that are now, or soon may be, on the market.

Alternatives to Urokinase for the Management of Central Venous Catheter Occlusion

The nationwide shortage of urokinase that began in late 1998 forced the medical community to find suitable alternatives to this agent for the management of various thrombotic processes. A high-use indication for urokinase in our institution is the management of occluded central venous catheters. A comprehensive search of the medical, pharmacy, and nursing literature produced limited but useful information on various alternative agents, including streptokinase, alteplase, hydrochloric acid, ethanol, and sodium hydroxide. This article reviews the available literature on each of these agents.

Alteplase (t-PA) Bolus: Occluded Catheters

Off-Label Drug Uses

ThisHospital Pharmacy feature is extracted from Off-Label DrugFacts, a quarterly publication available from Facts and Comparisons. Off-Label DrugFacts is a practitioner-oriented resource for information about specific FDA-unapproved drug uses. This new guide to the literature will enable the health care professional/clinician to quickly identify published studies on off-label uses and to determine if a specific use is rational in a patient care scenario. The most relevant data are provided in tabular form so that the reader can easily identify the scope of information available. A summary of the data—including, background, study design, patient population, dosage information, therapy duration, results, safety, and therapeutic considerations—precedes each table of published studies. Finally, references direct the reader to the full literature for more comprehensive information prior to patient care decisions.

Changes in tunneled catheter tip position when a patient is upright

PURPOSE

To determine the relative changes in position of tunneled catheters from supine to upright patient position and factors affecting catheter tip migration.

MATERIALS AND METHODS

One hundred forty-six different tunneled catheters were placed through the subclavian or jugular veins radiologically, and catheter positions were documented with use of cine radiography at the time of placement. Follow-up chest radiographs were obtained with the patient in the upright position within 48 hours after placement. Catheter tip positions were numbered from 1 to 8, with 1 representing the innominate/superior vena cava junction and 8, the lower right atrium. Patient sex and weight, the site of catheter entry, and the size and type of catheter were correlated with the relative change in position on the follow-up chest radiogrpahs.

RESULTS

There was a statistically significant (P < .0001) change in catheter position on the follow-up chest radiographs, with a mean difference of 1.5 catheter positions (usually mid-right atrium initially to low superior vena cava on follow-up). Catheter tip migration was greater for catheters in the subclavian veins, in females, and in obese patients.

CONCLUSIONS

The catheter tip migrates significantly from the initial position at the time of placement as compared to when the patient assumes the upright position. This knowledge is important in achieving the desired final catheter position.

Central venous catheter clots: incidence, clinical significance and catheter care in patients with hematologic malignancies

In a 7-month period we studied 38 Hickman central venous catheters (CVCs) positioned in children with hematologic malignancies with the aim of evaluating the incidence and clinical impact of CVC clots. Clots were found in 74% of the CVCs. Three methods of catheter care were developed for flushing the clotted CVCs: (a) use of a heparinized solution (400 IU/mL) on alternate days, (b) use of a heparinized solution (400 IU/mL) and saline solution containing urokinase (10,000 IU/mL) on alternate days, and (c) use of a saline solution containing urokinase (10,000 IU/mL) daily. Only method b decreased clot formation (33% success rate). There were no major mechanical complications in any of the CVCs with clots. Eighteen percent of patients with clots in their CVCs presented with CVC-related infections while no infective complications were observed in the patients without clots in their CVCs. In conclusion, CVC clots may predispose the patient to infections, which must be correctly treated.

Seldinger technique as an alternative approach for percutaneous insertion of hydrophilic polyurethane central venous catheters in newborns

The use of hydrophilic central venous catheters, percutaneously inserted by means of the Seldinger technique, was evaluated in this prospective study. Between 1988 and 1991, 138 catheters were inserted in newborns who were admitted to our neonatal intensive care unit. An adequate position of the tip, evaluated radiographically, was achieved in 130 (94.2%) of these insertions. The side effects associated with these 130 catheters and the duration of their use were recorded. Results were compared with those of percutaneously inserted Silastic catheters described in the literature. The rate of adequate catheter placement seems comparable. Because of a high rate of minor mechanical complications, the mean catheter duration was rather short (8.3 days). However, the incidence of serious complications, especially infectious complications, was low.

Central line occlusion with three-in-one nutrition admixtures administered at home

The use of single-container parenteral nutrition admixtures can be cost effective and can simplify home administration. Three-in-one admixtures (dextrose, amino acids, lipid emulsion, and other additives in a single bag) were in use when a marked increase in catheter occlusions was seen in the pediatric home parenteral nutrition population. Insoluble laminar deposits were found in the removed catheters. In all subsequently placed catheters, separate (SPLIT) infusions of lipid and parenteral nutrition solution were used rather than three-in-one admixtures. This was associated with an obvious decrease in catheter occlusions. Catheter life-span was retrospectively determined for 15 catheters of identical size and style that were used in eight patients who had received either infusions of three-in-one admixtures or SPLIT infusions. Life table survival analysis revealed a median survival time of 70 days for the three-in-one group (n = 8) and 290 days for the SPLIT group (n = 7). Survival distributions for the two groups were significantly different (p = .025). During the period of clustered catheter occlusion, the use of three-in-one admixtures that were stored in the home for up to 7 days was associated with a shortened catheter life-span. Occlusion or deposit development was not seen in catheters used for inpatient parenteral nutrition support when admixtures were prepared and infused within 28 hours. Catheter deposits were implicated as sanctuary sites for pathogenic bacteria in two patients. Failure to retrieve and inspect occluded catheters delayed the identification of the deposits.(ABSTRACT TRUNCATED AT 250 WORDS)

The incidence and management of catheter occlusion in patients on home parenteral nutrition

For patients on Home parenteral nutrition (HPN), catheter-related problems are the major source of morbidity and occlusion of the central venous catheter is one of these. We have managed 17 episodes of catheter occlusion in 10 patients on HPN. The median time from insertion to occlusive episode was 23 months. 10 catheters (59%) were saved by the used of thrombolytics (one by thrombolytics and ethanol) and 7 were replaced. The recent incidence of catheter occlusion in this cohort was one episode per 150 patient-months of HPN (0.08 episodes per year). Patients with Crohns disease appear to be at greater risk of developing catheter occlusion (p = <0.05).

Intravesical urokinase for the management of clot retention in boys

We successfully used intravesical urokinase in 2 young boys to relieve clot retention occurring as a consequence of upper tract bleeding. Urokinase clot dissolution appears to offer a simple, minimally invasive, atraumatic solution to this infrequent problem.

Occlusion of silastic broviac catheters as a result of twisting between the catheter and hub assembly

Occlusion is a common cause of catheter malfunction during home parenteral nutrition (HPN). We report 5 cases of central venous catheter occlusion, encountered over a 24 month period, which were associated with twisting of the catheter at the hub assembly. One catheter was replaced before the cause of the occlusion was identified. In 4 cases, twisting was noted prior to catheter removal, and this was corrected in three, allowing HPN to continue without catheter replacement. In 1 case the catheter was repaired. The current design of silastic Broviac catheters allows the catheter to twist around the hub assembly. Over-enthusiastic tightening of the cap of the catheter leads to twisting which causes catheter occlusion. A high index of suspicion should be maintained when dealing with catheter occlusion associated with silastic Broviac catheters. Recognition of the problem allows catheter salvage without recourse to catheter replacement.

Vascular access devices: perspectives on designs, complications, and management

The use of vascular access devices in hospitalized and home care patients has expanded rapidly in the past decade. New designs, materials, insertion techniques, and protocols for care related to vascular access devices have emerged. Complications associated with them, however, have remained a persistent problem. Septicemia, thrombosis, and occlusion are three of the more serious complications that can lead to the need for removal of the device. These complications are reviewed and areas for future research are identified.

Use of sodium hydroxide solution to clear partially occluded vascular access ports

Gradual vascular access port or tunneled central venous catheter occlusion during total parenteral nutrition is a common complication of unknown etiology, usually unresponsive to treatment with urokinase, ethanol, or hydrochloric acid. After establishing safety with regard to catheter materials and efficacy in dissolving the occluding substance in vitro, we treated a total of 13 vascular access ports (10 patients) that had occluded gradually during "three-in-one" total parental nutrition by slow perfusion with 10 to 20 mL of 0.1 mmol/mL sodium hydroxide solution. We found a mean increase in flow (results are flow rates under gravity-dependent vascular access port inlet pressure of 1.5 kPa) from 37 microL/s (95% upper confidence limit, 45 microL/s) to 75 microL/s (95% lower confidence limit, 64 microL/s; p < .001). For normal use, a flow of 50 microL/s is sufficient. There were no side effects. Five vascular access ports remained in excellent function during a follow-up period of 9 months. The others had reocclusions, but the partial reocclusions could be treated successfully.

Thrombolytic Therapy: A Comprehensive Review of Its Use in Clinical Medicine. Part II

The second part of this comprehensive review of thrombolytic therapy in clnical medicien focuses on its use in a wide renge of thrombotic disorders, including pulmonary embolism, deep venous thrombosis, arterial thrombocmbolism, catheter-related thrombosis, arterial thrombocmbolism, catheter-relted thrombosis, and prosthetic valve occlusion. New experimental applications in the management of unstable angina and cerebrovascular disease are also discussed.

Reoperation in patients with the short bowel syndrome

The clinical courses of 53 adult patients with the short bowel syndrome (SBS) were evaluated to determine the incidence of and indications for reoperation. Mesenteric vascular disease (23 patients) and malignancy/irradiation (18 patients) were the most frequent causes of resection. Early reoperation was necessary in nine (17%) patients, primarily for intestinal complications. Twenty (53%) of the 38 patients leaving the hospital required a later abdominal procedure during the mean follow-up of 30 months (range: 2 to 108 months). Three (33%) of nine patients with ulcer disease had gastric resection. Six (21%) of 28 patients at risk for cholelithiasis developed symptoms. Four of these patients underwent cholecystectomy, and three others had a prophylactic cholecystectomy. Ten patients underwent ostomy closure or formation. Intestinal disease necessitated stricturoplasty (three), serosal patch (one), minimal resection (three), or takedown of an ileal conduit (one). Twenty-four (63%) of 38 patients with SBS received home total parenteral nutrition for a mean of 22 months (range: 2 to 105 months). Eleven patients required more than 1 vascular access procedure, and 4 had more than 3 procedures. Patients with the SBS frequently require reoperation for intestinal conditions, cholelithiasis, peptic ulceration, and vascular access. Prophylactic cholecystectomy and strategies for preserving intestinal length are important considerations in these patients.

Thrombosed central venous catheters: restoring function with 6-hour urokinase infusion after failure of bolus urokinase

Nineteen central venous catheters with radiographically proven thrombotic occlusion failed to have function restored with a mean of 1.6 5000-unit boluses of urokinase per catheter. Catheters then underwent a 6-hour infusion of urokinase at 40,000 units per hour followed by repeat contrast injection and evaluation of function. Reduction in thrombus size occurred in all but one patient. Catheter function was restored in 15 patients. In two patients, thrombus dissolved but catheters remained occluded because of tip malposition. In the remaining two patients, catheter function was restored with an additional 6-hour infusion. No adverse reactions to the infusion were seen. After infusion catheters continued to function normally for a mean of 36.2 days. Five catheters rethrombosed, two of which responded to urokinase bolus instillation. Thrombosed catheters failing standard intracatheter bolus urokinase are generally salvaged with a 6-hour infusion of low-dose urokinase.

Fibrinolytic therapy in a patient with Denver peritoneovenous shunt occlusion

Urokinase thrombolytic therapy was used on three separate occasions to lyse thrombosed Denver peritoneovenous shunts in a 51-year-old woman. Shunt patency was preserved over a 2-year period, with a fatal complication following the third procedure. The authors suggest that thrombolytic therapy might be a viable alternative to immediate surgical revision in patients with failed Denver shunts.