Low-dose streptokinase for occluded Hickman catheters

Streptokinase Therapy for Occluded Tenckhoff Catheters in Children on CAPO

Streptokinase was infused through the partially thrombosed Tenckhoff catheters of four children on continuous ambulatory peritoneal dialysis (CAPD). Radiographic contrast studies performed before and after the infusions demonstrated dramatic dissolution of the fibrin thrombi associated with restoration of normal catheter function. The catheters subsequently functioned for an average of 12.5 months. No allergic or hemorrhagic complications were noted in association with the infusions. Coagulation studies revealed no evidence for systemic streptokinase absorption. We suggest that streptokinase, when given in the manner described, is a safe and effective treatment of thrombosed Tenckhoff catheters in children.

Analysis of early failure of tunneled hemodialysis catheters

OBJECTIVE

Tunneled hemodialysis catheters are often placed by the interventional radiology service using sonographic guidance and fluoroscopy for safe and optimal placement. The aim of this study was to determine the causes of early failure (<or=7 days) of these catheters in our practice.

SUBJECTS AND METHODS

Data were prospectively collected for 639 radiologically placed tunneled hemodialysis catheters. The reason for catheter removal was recorded in each case. Tips of removed catheters were routinely sent for microbial culture.

RESULTS

Fifty-two (8.1%) of 639 catheters were removed within 7 days of insertion. Six (0.9%) of these had completed their purpose and had not failed; these were not included in the study. Of the 46 catheters having early failure, six (0.9%) were clotted and 12 (1.9%) were suspected of being infected, only three of which had a proven catheter-related infection. Twenty-eight catheters (4.4%) were removed for other reasons. In this group, the most common reasons were poor tip position (n = 9) and catheter replacement over a guidewire into a preexisting fibrin sheath (n = 8). Only two failed because of poor tip orientation. Other reasons for failure were kinked or pinched catheters (n = 4) and bleeding (n = 3), including one exsanguination, and two unknown reasons.

CONCLUSION

By paying careful attention to catheter tip position, searching diligently for the presence of a fibrin sheath when catheter exchanges are made over a wire, and better investigating presumed catheter infection, we could reduce the early failure rate by more than half, from 46 cases to 20 cases (nine cases of suspected infection were in fact not infected).

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.

Histologic development of the sheath that forms around long-term implanted central venous catheters

BACKGROUND

Chronically implanted catheters often become covered with a thin, white adherent covering of tissue that has been referred to as a fibrin sheath. This tissue often interferes with catheter function.

METHODS

To chronicle the development of this sheath, rats were implanted with silicone rubber central venous catheters. Five rats were euthanized at 3,7, and 60 days postimplantation so that gross necropsy and histology could be performed on the catheterized vessels.

RESULTS

The coating that developed around the external portion of the catheter started as a dark red thrombus containing fibrin and progressed into vascularized, fibrous connective tissue.

CONCLUSIONS

The translucent to white sheath that forms around chronically implanted catheters is not composed of fibrin and is therefore not likely to be dissolved by fibrinolytic agents such as urokinase, streptokinase, or tissue plasminogen activator.

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).

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.

[Thrombosis of the superior vena cava after prolonged catheterization. Treatment by progressive removal of the catheter combined with urokinase-heparin administration]

A retrospective study of 13 cases of complete superior vena cava thrombosis due to prolonged catheterization is reported. All the polyurethane catheters had been inserted by anaesthetists in theatre between January 1985 and December 1989, using Seldinger's technique. On the 10th day after the first catheter had been placed, the catheter was replaced by using a guide wire. Superior vena cava obstruction was diagnosed clinically (eyelid, neck, facial and upper limb oedema, cyanosis, collateral venous circulation, lack of blood reflux in the catheter). The clinical diagnosis was confirmed by phlebography. Treatment consisted in administration of urokinase (1,500 IU.kg-1.h-1), together with 10,000 to 25,000 IU.day-1 of heparin, both being injected via the catheter. The catheter was removed progressively (1 cm every 2 to 4 h). As soon as a venous pressure curve was obtained, the catheter was completely removed. Overall 8,784 catheters were inserted during that period. The incidence of superior vena caval obstruction may therefore be estimated to be 1.48 per 1,000 catheters. The catheters remained in place up to a mean of 14.75 +/- 9.6 days before the obstruction occurred. Treatment with urokinase and heparin lasted a mean of 2.53 +/- 1 days. The clinical picture returned to normal in all 13 patients. Phlebography carried out in three of them, after treatment, showed an excellent degree of venous repermeability. Thrombolysis was confirmed by the increase in the concentration of D-dimers, without any decrease in fibrinogen concentration. There were five haemorrhagic complications, including two haematomas of the psoas muscle, one of which required surgical drainage.(ABSTRACT TRUNCATED AT 250 WORDS)

Obstructed central venous catheters. Restoring function with a 12-hour infusion of low-dose urokinase

Thrombotic obstruction frequently prohibits infusion through or withdrawal of blood from central venous catheters and can occur in conjunction with symptomatic thrombosis of the subclavian vein. Thirty catheters were radiographically proved to be obstructed by thrombus and had not responded to at least one instillation of 5000 units of urokinase. All catheters were treated with a 12-hour infusion of urokinase at the rate of 40,000 units/hour. The obstructing thrombus was either eliminated or reduced in size in all instances and full function was restored in all but one catheter. No bleeding complications were seen. Six patients with obstructed catheters also had symptoms of subclavian vein thrombosis. All patients with symptoms of subclavian vein obstruction became asymptomatic on anticoagulant therapy even though no attempt at dissolving the thrombus obstructing the subclavian vein was made. A 12-hour infusion of low doses of urokinase can safely salvage function of obstructed catheters that otherwise may require replacement. Patients with concomitant subclavian vein thrombosis become asymptomatic on anticoagulant therapy without need to dissolve the obstructing thrombus.

Efficacy of thrombolytic therapy for occlusion of long-term catheters

Nineteen ambulatory outpatients requiring a tunneled central venous access device with catheter occlusion were studied. Mean catheter life was 7.9 +/- 8.2 months (range, from 1-36 months) at the time of the occlusion. Urokinase (5000 units/ml) was injected in sufficient amount to fill the internal volume of the catheter and allowed to stay for 5 to 10 min before attempting to aspirate. Repeated aspiration attempts were performed every 5 to 10 min for a maximum of 30 to 60 min or patency. In the event catheter patency was not restored, the thrombolytic solution was aspirated from the catheter and a maximum of two additional trials were instituted. Results included clearance of four out of 15 withdrawal occlusions (27%) and two out of four resistance to infusion occlusions (50%). Overall, successful catheter clearance occurred in six out of 19 occlusions (32%). The efficacy rate of thrombolytic therapy for successfully clearing occluded catheters at our institution using conventional low-dose thrombolytic therapy is markedly lower than previously reported rates of 57 to 100%. The reasons for this discrepancy may reflect differences in dosage of thrombolytic agent, method of administration, frequency of monitoring of catheter patency, and catheter life.

Treatment of an infected silicone right atrial catheter with combined fibrinolytic and antibiotic therapy: case report and review of the literature

Tunnelled silicone rubber right atrial catheters are commonly used to administer long-term total parenteral nutrition (TPN), cancer chemotherapeutic agents, and antimicrobial agents. The indwelling devices potentiate platelet-fibrin thrombi formation, providing a nidus for infection. Although many episodes of sepsis associated with thrombotic tunnelled catheters respond to antimicrobial therapy alone, a significant number require catheter removal. Evidence from case studies and small clinical trials suggests that fibrinolytic agents may increase the response rate and prevent removal of the device when combined with antimicrobial therapy. We present the first case reported of bacterial sepsis secondary to a thrombotic indwelling Hickman catheter for long-term TPN successfully treated with a combination of streptokinase and antibiotic therapies.

Application of thrombolytic therapy in vascular occlusive disease. A surgical view

The use of fibrinolytic agents to control the fibrinolytic enzyme system and lyse pathologic fibrin deposits or thrombus has now assumed a position with anticoagulants and vascular surgery in the physician's therapeutic armamentarium. The principal exogenous activators that are used clinically are streptokinase, urokinase, and tissue plasminogen activator. Acute arterial occlusions are more likely than chronic occlusions to respond to thrombolytic therapy, especially if treatment is instituted within a few hours of onset of symptoms and if the disease is due to embolic material rather than in situ thrombosis. Since the duration of drug infusion necessary to lyse arterial thrombus cannot be predicted, patients in whom tissue viability cannot be determined or in whom ischemia cannot be tolerated during the drug infusion interval are not candidates for intraarterial fibrinolytic drug infusion. In treating patients with venous occlusion, thrombolytic therapy is more effective against proximal clots than in calf thrombosis. No protective effect from pulmonary embolism has been noted in trials comparing heparin with streptokinase. Fifty percent of patients with an initial episode of deep venous thrombosis treated within 72 hours of onset will have complete resolution of thrombus with preservation of valve function.

The malfunctioning silastic catheter--radiologic assessment and treatment

Occlusion of silastic catheters is attributed to several documented causes. One factor not yet adequately documented is fibrin sleeve formation. In this instance, the catheter functions for infusion purposes, but blood withdrawal is no longer feasible. This is a troublesome occurrence when encountered in the clinical setting. This report reviews the assessment of fibrin sleeve formation, the use of catheter phlebography and treatment with low-dose streptokinase. Seventeen instances of the inability to aspirate blood from silastic catheters are evaluated with restoration of full catheter function in all cases after streptokinase administration.

DSA evaluation of indwelling central venous catheters

Indwelling central venous catheters are widely used for the management of many disorders but have a high incidence of dislodgement, thrombosis, or occlusion. Contrast studies of these complications are hampered by difficulty injecting contrast through the catheters or peripheral veins. Use of digital subtraction angiography allows adequate visualization with small amounts of contrast and greatly facilitates the study of these catheters and the surrounding venous system.