Use of Dacron cuffed silicone catheters as long-term hemodialysis access

Salvage Insertion of Tunneled Central Venous Catheters in the Internal Jugular Vein after Accidental Catheter Removal

Purpose

Tunneled catheters are widely used for intermediate to long-term hemodialysis (HD) access, but are prone to several complications that can require catheter replacement. Replacing malfunctioning catheters with a new line, placed in a different access site, can lead to problems with multiple vein occlusions. This has led many nephrologists to continue using the same vein as long as possible by guidewire catheter exchanges, to preserve other veins for future use. We describe a guidewire exchange technique for the Ash-Split catheter in the internal jugular vein.

Methods

In three patients, the exchange was performed because of partial catheter removal, as evidenced by the outward dislocation of the Dacron cuff. In these patients, the guidewire was inserted through the catheter. In two additional patients, the catheter had been completely removed by accident: the replacement of the dislodged tunneled venous catheters was attempted 5 hr and 1 day after accidental removal. In these patients, the guidewire was inserted through the previous tunnel. After guidewire placement, a skin incision was made in the supraclavicular region. The metal guidewire was easily located inside the fibrous structure that had previously surrounded the catheter. The guidewire was then extracted from the subcutaneous tunnel and used to insert a new catheter safely and easily after creating a new tunnel. Patients were routinely given antibiotic prophylaxis (1 g of cefazolin) immediately before the procedure. A strict aseptic technique was used, including several sterile glove changes.

Results

No infections developed following this procedure, which has the potential for bacterial contamination. All procedures were successful. Only in one patient did we have to convert to a different catheter: it was not possible to replace the old Ash-Split catheter with the same dual-lumen catheter because of difficulties in inserting the peel away introducer-catheter complex. In this patient, rather than forcing it with larger dilators or trying to disrupt the fibrin sheath with balloon dilatation, a single lumen Tesio catheter was successfully placed. In both patients who completely lost the previous catheter, the guidewire was readily reinserted through the subcutaneous tunnel into the vein. Catheter function was excellent in all patients, with a test blood flow rate on the 1st catheter use >350 ml/min.

Conclusions

We described a new method for catheter exchange, which allows the easy insertion of a new catheter and the creation of a new and safer subcutaneous tunnel. In addition, we demonstrated that in cases of complete catheter removal, it is possible to reinsert a catheter in the same vein through a guidewire, even when reinsertion was attempted up to 1 day later.

Type of peritoneal dialysis catheter and outcomes

In peritoneal dialysis (PD), a well-functioning catheter is of great importance, because a dysfunctional catheter may be associated with incidence of peritonitis, efficiency of dialysis, and to the overall quality of treatment, representing one of the main barriers to optimal use of PD. When considering the relationship between PD catheter type and outcomes, we should keep in mind the different types of available PD catheters, those that are most commonly used in clinical practice, and the available head-to-head comparisons in the literature. The main differences in PD catheter design include the number of cuffs, the shape of subcutaneous tract (straight vs. swan neck), and the shape of intraperitoneal tract (straight vs. coiled). The availability of the best catheter design and materials, along with a skillful management of PD access, may have the greatest impact on long-term patient outcome on PD. It is now established that the use of straight catheters may improve outcomes and technique survival, but further advances in PD catheter technology can potentially improve technique survival. The self-locating PD catheter is a well established device that has not been fully studied and it may represent, based on the available observational evidence and on the clinical experience, an already existing technological advance deserving further studies.

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.

Recombinant tissue plasminogen activator infusion for hemodialysis catheter clearance

Hemodialysis (HD) catheter occlusion is a common cause of poor blood flow and inadequate dialysis. In order to address this problem in our pediatric dialysis unit, we elected to use short (2-h) infusions of low-dose recombinant tissue plasminogen activator (rtPA) for thrombolysis of occluded catheters. Catheters meeting diagnostic criteria for thrombosis were infused with 2.5 mg rtPA in 25 ml 0.9 normal saline over 2 h prior to dialysis. Retrospective data collection was carried out to assess the success of this procedure. Variables assessed included blood flow (Qb), transmembrane pressure (TMP) and venous pressure (VP) before and after rtPA infusion. Seven catheter thromboses in six patients were successfully treated with rtPA; there were significant improvements in Qb ( p <0.01), TMP ( p <0.01), and VP ( p <0.02). At 32 weeks after rtPA therapy, Kaplan-Meier survival analysis showed a 60% probability of primary catheter patency. At the end of the study, 85% of catheters had adequate function as defined by a Qb >200 ml/min. No adverse events were observed. Low-dose rtPA infusion is safe and effective for catheter thrombolysis in outpatient pediatric HD patients. It may serve as an alternative method of administration to local instillation and may be used to restore patency before resorting to surgical revisions.

A prospective study of hemodialysis access-related bacterial infections

The objective of this study was to describe hemodialysis vascular-access related infections that occurred in hemodialysis patients over an 18-month period. The study is a prospective descriptive analysis of incidence infection rates in a hemodialysis unit in a tertiary-care medical center. Prospective surveillance for hemodialysis vascular access-related infection was performed for all patients undergoing hemodialysis from November 1999 through April 2001 at King Fahd Hospital of King Faisal University, Al-Khobar, Saudi Arabia. The total number of dialysis sessions was calculated. The type of vascular access was noted. Cultures were obtained and all infections were recorded and infection rates were calculated. There were 9627 hemodialysis sessions (5437 via permanent fistulae or grafts, 2409 via temporary central catheters, and 1781 via permanent tunneled catheters) during the 18-month study period. We identified a total of 109 infections, for a rate of 11.32/1000 dialysis sessions (ds). Of the 109, 23 involved permanent fistulae or grafts (4.23/1000 ds); 18 involved permanent-tunneled central catheter infections (10.1/1000 ds); and 68 involved temporary-catheter infections (28.23/1000 ds). There were 38 bloodstream infections (3.95/1000 ds) and 34 episodes of clinical sepsis (3.53/1000 ds). Seventy-one vascular access infections without bacteremia were identified (7.38/1000 ds), including 16 permanent-fistulae or graft infections (2.94/1000 ds), 7 permanent-tunneled central catheter infections (3.93/1000 ds), and 48 temporary-catheter infections (19.92/1000 ds). Staphylococcal organisms were responsible for 77% of the infections, with Staphylococcus epidermidis being the strain most commonly implicated. Gram-negative organisms were responsible for 23% of the infections. In conclusion, infection rates were highest in hemodialysis patients with temporary vascular access, compared with rates in those with permanent arteriovenous fistulae and synthetic grafts. Most of the bacterial organisms isolated from the vascular access sites were gram-positive cocci, with S. epidermidis accounting for 50% of the organisms. The rate of infection with gram-negative bacilli was higher than in other reports. Our greater dependence on central venous catheters, due to local factors, coupled with the immune-compromising comorbid conditions of our patients, may be contributory to the pattern of infection reported. Delays in the creation of vascular grafts for hemodialysis access should be avoided.

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).

Central venous dialysis catheters: catheter-associated infection

Tunneled dialysis catheters (TDC) are extensively used for long-term venous hemodialysis access and their use is frequently associated with infectious complications. Catheter-related bacteremia (CRB) is the most common and important infection associated with TDC use and may be caused by a wide variety of Gram-positive or Gram-negative organisms. Prevention of CRB can be difficult despite use of rigorous infection-control techniques for catheter insertion and access. A number of antibacterial catheter-packing solutions hold promise for reduction of CRB. Treatment of CRB with antibiotics alone yields poor results and may increase the risk for other infectious complications, especially endocarditis. In selected cases where initial infection control can be achieved with antibiotics, guidewire exchange of the TDC results in cure rates equivalent to those of TDC removal and subsequent replacement. Dialysis programs should monitor TDC infections with attention to incidence, bacteriology, and outcomes.

Guidelines for the management of intravascular catheter-related infections

These guidelines from the Infectious Diseases Society of America (IDSA), the American College of Critical Care Medicine (for the Society of Critical Care Medicine), and the Society for Healthcare Epidemiology of America contain recommendations for the management of adults and children with, and diagnosis of infections related to, peripheral and nontunneled central venous catheters (CVCs), pulmonary artery catheters, tunneled central catheters, and implantable devices. The guidelines, written for clinicians, contain IDSA evidence-based recommendations for assessment of the quality and strength of the data. Recommendations are presented according to the type of catheter, the infecting organism, and the associated complications.

Intravascular catheter-related infections are a major cause of morbidity and mortality in the United States. Coagulase-negative staphylococci,Staphylococcus aureus, aerobic gram-negative bacilli, andCandida albicansmost commonly cause catheter-related bloodstream infection. Management of catheter-related infection varies according to the type of catheter involved. After appropriate cultures of blood and catheter samples are done, empirical iv antimicrobial therapy should be initiated on the basis of clinical clues, the severity of the patient's acute illness, underlying disease, and the potential pathogen (s) involved. In most cases of nontunneled CVC-related bacteremia and fungemia, the CVC should be removed.

Tunneled hemodialysis catheter survival: comparison of radiologic and surgical implantation

Cuffed, tunneled hemodialysis catheters (caths) are often implanted in the operating rooms (OR) by surgeons or by interventional radiologists in radiology suites (RS). Comparative outcome studies between OR and RS placed caths are few and tend to favor the specialty of the authors. In this longitudinal study, we monitored cath survival in patients while awaiting maturation of their fistulae, and compared outcomes between OR and RS placement. A total of 95 caths were placed in 50 patients between July 1996 and July 1999. Radiologically placed caths had a shorter primary patency duration than OR placed caths (80 +/- 40 days vs. 100 +/- 31 days, p = 0.04) and a lower primary patency rate at 120 days than OR placed caths (42% vs. 67%, p = 0.04). Cumulative infection rate per 1,000 catheter days was higher in RS than OR cases (3.8 Vs 2.2, p = 0.09), whereas mean sepsis free duration was shorter in RS than OR (60 +/- 45 days vs. 88 +/- 40 days, p = 0.02). The risk of infection was 1.7 times greater in RS than OR cases (chi-square = 6.4, p = 0.01). The RS placed caths also had a higher rate of primary nonfunction (31% vs. 8.3%, p = 0.04) and bleeding complications (42% vs. 17%, p = 0.04), but significantly shorter procedure scheduling time than OR cases (1.1 +/- 0.3 days vs. 2.5 +/- 0.6 days, p < 0.0001). In conclusion, radiologically placed caths seem to have higher rates of infection, bleeding, and functional failure but shorter scheduling time than surgically placed caths. Discussions are under way to improve the survival of RS placed caths at our affiliated hospitals.

Direct peripheral venopuncture: another new choice of temporary vascular access

BACKGROUND

Femoral, subclavian, and internal jugular veins access have been widely used for temporary vascular access for hemodialysis, but their use has been associated with a significant complication rate. We report in three selected hemodialysis patients with the procedure of direct peripheral venopuncture as temporary vascular access to reduce complications.

METHODS

We have demonstrated hemodialysis via direct puncture of peripheral veins of the antecubital fossa (cephalic vein in the process of arterial inflow to dialyzer and venous outflow from dialyzer to basilic vein) as temporary vascular access for these patients.

RESULTS

Renal function of case 1 and case 2 progress to normal status after several sessions of dialytic therapy as well as quit hemodialysis, and case 3 successfully shifts to peritoneal dialysis following four sessions of dialytic therapy.

CONCLUSIONS

We recommend this short-term access contribute a important additional new choice in selected patients with acute, reversible renal failure, obstructive uropathy, initiation of peritoneal dialysis, patients on peritoneal dialysis with peritonitis, or under plasmapheresis therapy.

Standardized surveillance of hemodialysis vascular access infections: 18-month experience at an outpatient, multifacility hemodialysis center

OBJECTIVE

To develop a standardized surveillance system for monitoring hemodialysis vascular-access infections in order to compare infection rates between outpatient sites and to assess the effectiveness of infection control interventions.

DESIGN

Prospective descriptive analysis of incidence infection rates.

SETTING

An outpatient hemodialysis center with facilities in Idaho and Oregon.

PATIENTS

All outpatients receiving chronic outpatient hemodialysis.

RESULTS

There were 38,096 hemodialysis sessions (31,603 via permanent fistulae or grafts, 5,060 via permanent tunneled central catheters, and 1,433 via temporary catheters) during an 18-month study period in 1997 to 1998. We identified 176 total infections, for a rate of 4.62/1,000 dialysis sessions (ds). Of the 176, 80 involved permanent fistulae or grafts (2.53/1,000 ds), 69 involved permanent tunneled central catheter infections (13.64/1,000 ds), and 27 involved temporary catheter infections (18.84/1,000 ds). There were 35 blood-stream infections (0.92/1,000 ds) and 10 episodes of clinical sepsis (0.26 /1,000 ds). One hundred thirty-one vascular-site infections without bacteremia were identified (3.44/1,000 ds), including 65 permanent fistulae or graft infections (2.06/1,000 ds), 42 permanent tunneled central catheter infections (8.3/1,000 ds), and 24 temporary catheter infections (16.75/1,000 ds).

CONCLUSIONS

Infection rates were highest among temporary catheters and lowest among permanent native arteriovenous fistulae or synthetic grafts. This represents the first report of extensive incidence data on hemodialysis vascular access infections and represents a standardized surveillance and data-collection system that could be implemented in hemodialysis facilities to allow for reliable data comparison and benchmarking.

Recombinant tissue plasminogen activator is a useful alternative to heparin in priming quinton permcath

Soft, cuffed, implantable central venous catheters such as the Quinton Permcath (Quinton Instrument Co, Seattle, WA) are increasingly used as permanent access in patients with end-stage renal disease. Their major limitations, besides infection, are thrombosis and inadequate blood flow. To prevent those complications, heparin is conventionally used for priming the Quinton Permcath between dialysis sessions. In this study, we compared recombinant tissue plasminogen activator (rTPA) with heparin for priming the Quinton Permcath in a prospective, randomized, crossover design. Twelve patients were randomly assigned to receive 2,000 IU of heparin or 2 mg of rTPA injected into each catheter lumen at the end of each dialysis session over a period of 4 months, followed by a switch to the other substance. Blood flow rate (flow), venous pressure (VP), and arterial pressure (AP) were monitored at each dialysis session hourly. Flow was significantly greater (P = 0.0001) with rTPA (mean +/- SD, 237.7 +/- 18.1 and 231.6 +/- 12.4 mL/min for the first and second 2 months, respectively) compared with heparin (208.5 +/- 10.1 and 206.9 +/- 14.2 mL/min for the first and second 2 months, respectively). VP was significantly less (P = 0.0001) with rTPA (135.4 +/- 8.2 and 140 +/- 15.2 mm Hg for the first and second 2 months, respectively) compared with heparin (160.5 +/- 16.1 and 159.2 +/- 20.7 mm Hg for the first and second 2 months, respectively). AP was significantly greater (P = 0.0002) with rTPA (-113.5 +/- 11.8 and -115.9 +/- 12.7 mm Hg for the first and second 2 months, respectively) compared with heparin (-136.5 +/- 23.3 and -134.7 +/- 25.8 mm Hg for the first and second 2 months, respectively). In addition, fewer complications (flow problems, clotting, and need for fibrinolysis) occurred in the rTPA period. These results show that rTPA is superior to heparin for priming the Quinton Permcath between hemodialysis sessions and can be used as a valuable alternative to conventional heparin in selected patients.

Bacteremia associated with tunneled, cuffed hemodialysis catheters

Bacteremia is a frequent complication associated with tunneled, cuffed, permanent catheters (PCs). The incidence, spectrum of infecting organisms, and optimal treatment for catheter-associated bacteremia (CAB) have not been clearly established. In this study, 101 chronic hemodialysis (HD) patients with PCs for blood access were prospectively monitored for infection during a 24-month period. Data recorded for each patient included the number of catheter-days, episodes of suspected bacteremia, blood culture results, method of treatment, complications, and outcomes. All patients with CAB were treated with a 21-day course of intravenous antibiotics. The PC was removed if the patient had uncontrolled sepsis or if other vascular access was ready for use. Once the infection was controlled, catheter salvage was attempted, either by exchanging for a new catheter over a guidewire or treating with antibiotics only, leaving the original PC in place. Catheter exchange was the recommended approach in our program, but this was decided in each case by the treating nephrologist. During this study, there were 15,581 catheter-days, with 86 episodes of CAB, or 5.5 episodes/1,000 catheter-days (95% confidence interval, 4.5 to 6.8/1,000 d). Forty-five infections (52.3%) were caused by gram-positive cocci only, including Staphylococcus aureus, coagulase-negative Staphylococcus, and Enterococcus species. Twenty-three infections (26.7%) were caused by gram-negative rods only, including a wide variety of enteric organisms. Eighteen infections (20.9%) were polymicrobial. Thirty-nine of 86 episodes (45.3%) included at least one gram-negative organism. Five PCs were removed because of severe uncontrolled sepsis, and eight PCs were removed because they were no longer required. Of the remaining 73 cases, attempted PC salvage was successful in 11 of 30 patients (36.7%) treated with antibiotics alone versus 35 of 43 patients (81.4%) who underwent PC exchange in addition to antibiotic therapy (P = 0.0005). The only important complication of CAB was endocarditis, occurring in 3 of 86 episodes (3.5%). We conclude that in our HD units, CAB is relatively common and frequently involves gram-negative bacteria. PC salvage is significantly improved when antibiotic treatment is combined with PC exchange over a guidewire.

Interventional radiology placement of twin Tesio catheters for dialysis access: review of 75 patients

PURPOSE

To evaluate the safety and efficacy of modern interventional radiology techniques and imaging guidance for placement of jugular vein twin Tesio hemodialysis catheters.

MATERIALS AND METHODS

Eighty-two sets (75 patients) of twin Tesio catheters were percutaneously placed in the right (n = 70) and left (n = 12) internal jugular veins with use of ultrasound (US) and fluoroscopic guidance. Immediate procedural and late complications were recorded. The efficacy of the Tesio system was also evaluated.

RESULTS

With US and fluoroscopic guidance, the technical success for access and catheter placement was 100%. Measured dialysis blood flow rate of greater than 375 mL/min was obtained in 95% of the patients and recirculation averaged 4.6% +/- 5%. An inadvertent common carotid artery puncture occurred in one (0.6%) patient and prolonged exit site bleeding occurred in another five patients (3%). Each of these was successfully controlled with compression. More chronically, catheter thrombosis and exit site infection occurred each at the rate of 0.16 episodes per 100 catheter days. All thrombosis and exit site infections responded to local thrombolysis and antibiotic therapy, respectively. Bacteremia occurred in 20 patients and required catheter removal in five patients. There was no clinical evidence of upper extremity or superior central vein thrombosis.

CONCLUSION

Placement of internal jugular, twin Tesio catheters with use of imaging and interventional techniques provides a safe and efficacious means of either short or long-term hemodialysis.

Replacement of failing tunneled hemodialysis catheters through pre-existing subcutaneous tunnels: a comparison of catheter function and infection rates for de novo placements and over-the-wire exchanges

PURPOSE

Tunneled hemodialysis catheter dysfunction often occurs from fibrin sheath formation. As a way to preserve existing catheter venous access sites, the authors evaluated over-the-wire exchange of catheters through pre-existing subcutaneous tunnels as an alternative to catheter removal and de novo catheter replacement.

PATIENTS AND METHODS

One hundred nineteen catheters were placed in 68 patients. Seventy-seven catheters were placed de novo and 42 catheters were placed through the pre-existing subcutaneous tunnels of failing catheters. Technical success, short-term complications, infection rates, and functional catheter longevity were evaluated.

RESULTS

Technical success for catheter exchange was 93%. Infection rates were comparable to those of de novo catheter placement: 0.15 and 0.11 infections per 100 catheter days for de novo and exchanged catheters, respectively. Catheter duration of function was not significantly different for de novo versus exchanged catheters: 63% and 51% at 3 months, 51% and 37% at 6 months, and 35% and 30% at 12 months, respectively.

CONCLUSIONS

Over-the-wire exchange of tunneled hemodialysis catheters is safe and easily performed. It causes no increase in infectious complications and provides similar catheter longevity to de novo catheter placement. The procedure is an important option for prolonging tunneled hemodialysis catheter access sites.

Applications and outcome of hemodialysis in cats: a review of 29 cases

Hemodialysis (HD) has been used in the management of renal failure in dogs, but its feasibility has not been reported for uremic cats. Therefore, we investigated the technical possibility, efficacy, and complications of intermittent HD in cats with severe uremia. A total of 160 HD treatments were performed on 29 cats with acute renal failure (ARF) (n = 15), chronic renal failure (CRF) (n = 6), or acute on CRF (n = 8) between November 1993 and June 1996. Hemodialysis treatments were performed with transcutaneous dialysis catheters using a bicarbonate-based delivery system, sodium modeling, and volumetric-controlled ultrafiltration. Presenting serum chemistries (mean +/- SD) for all cats were creatinine, 16.4 +/- 7.5 mg/dL; blood urea nitrogen (BUN), 229 +/- 87 mg/dL; phosphate, 15.4 +/- 5.4 mg/dL; potassium, 6.0 +/- 1.6 mEq/L; and HCO3-, 16.0 +/- 4.4 mEq/L. For intensive HD treatments, pre-HD versus post-HD creatinine changed from 10.3 +/- 4.4 to 1.6 +/- 0.9 mg/dL and BUN from 105 +/- 33 to 8 +/- 10 mg/dL. One or more adverse events occurred during 111 (69%) treatments. Dialysis-related events included hypotension, dialysis dysequilibrium, clotting, and bleeding. Nine of 15 (60%) cats with ARF and 1 cat with CRF recovered sufficiently to survive without ongoing need for HD. For the remaining cats, the proximate causes of death were dialysis related in 9 cats, uremia related in 6 cats, and iatrogenic or unknown in 4 cats. Hemodialysis is technically feasible and effectively controls the biochemical disturbances of uremic cats. It is especially valuable for the management of severe ARF, permitting recovery in a large number of cats refractory to conventional therapy. Technical complications and chronic debility, however, may limit its usefulness for cats with advanced CRF.

Stripping of failing haemodialysis catheters using the Ampltaz gooseneck snare

The development of a fibrin sheath at the tip of a long-term haemodialysis catheter may lead to deteriorating blood flow rates, resulting in inadequate haemodialysis. Restoration of functional patency has been described using the technique of percutaneous fibrin sheath stripping (PFSS) using a wire snare device. Our purpose was to assess this technique within an established renal vascular access service. All catheters referred for the assessment of low blood flow rates on dialysis were considered for the procedure. Initial fluoroscopic assessment of the catheter was followed by stripping of the tip of the catheter using a gooseneck snare. Seventeen of 22 well-positioned catheters undergoing a single PFSS attempt were restored to function with a median prolongation of patency of 4.25 months. Two catheters underwent a second PFSS procedure providing additional patency. Nineteen of a total of 24 (79%) PFSS procedures successfully restored catheter function. Seven catheters with poorly positioned tips or a kink were not restored to functional patency using PFSS. Two patients developed a puncture site haematoma. No patient developed symptoms of pulmonary emoblism. In conclusion, PFSS restored function in 79% of attempts in well positioned catheters. The method is technically straightforward, with a low complication rate and has become a routine part of the renal vascular access service.

Central venous catheters for maintenance hemodialysis: a cautionary approach

There is an increasing trend toward the use of indwelling central venous catheters (CVC) for maintenance hemodialysis. Although such devices are necessary in some problematic cases, the general use of CVC is worrisome. Not only may CVC prejudice the ultimate success of future permanent vascular access, but CVC also may be associated with reduced dialysis delivery and with several important complications. This review summarizes recent developments in catheter design, placement techniques, maintenance of the indwelling catheter, and complications of CVC use. Based on cumulated experience, a judicious position is taken that recognizes the place of CVC among the various access options but that favors permanent vascular access whenever feasible.

Polyurethane catheters for long-term hemodialysis access

Chronic hemodialysis patients with failed native fistulas and/or synthetic arteriovenous grafts are usually dialyzed via surgically placed silicone jugular catheters such as the PermCath (Quinton, Seattle, WA, U.S.A.). We report a successful experience with the use of double lumen polyurethane central venous catheters placed percutaneously. Catheters with poor flows were replaced over a guidewire at the bedside. Eleven long-term hemodialysis patients failed arteriovenous access, 9 of them having had multiple attempts at fistulas and/or grafts. Seven of these patients had also failed peritoneal dialysis. They were dialyzed with polyurethane catheters for a mean of 681 +/- 280 days (range 282-1150 days), requiring a mean of 3.4 +/- 0.4 new venous punctures and 8.2 +/- 1.5 catheter changes over a guidewire over that period of time. Actuarial patient survival was 50% at 2 years, and mean urea reduction during dialysis was 64.2 +/- 1.7%. The septicemia rate was only 1.2 episodes per 1,000 catheter-days, but about 20% of patients experienced central venous occlusion, attributable to the use of subclavian catheter placement in 82% of the sites. The success of this technique and its elimination of the need for urokinase, radiologic interventions, and surgical placement warrant its consideration as an acceptable form of long-term vascular access, provided jugular placement allows reduced central venous occlusion rates.

Tearing down the barriers to daily home hemodialysis and achieving the highest value renal therapy through holistic product design

Renal therapy value can be defined as the ratio of outcomes achieved by a dialytic therapy to the total cost of providing that therapy. One desirable goal of any dialysis modality would be the achievement of maximum value. Unfortunately, with conventional hemodialysis and peritoneal dialysis modalities, improving outcomes has always been linked to a simultaneous increase in costs, thereby leaving value relatively unchanged. However, a new modality, daily home hemodialysis, finally may allow this linkage to be broken. The outcomes are dramatically improved as a result of a higher quantity and quality of dialysis dose resulting from the greater frequency of treatments. The costs can be reduced by minimizing the consumed items, avoiding the labor and overhead of dialysis clinics, and reducing the costs associated with morbidity. Provision of this therapy is, however, predicated on the availability of instrumentation designed specifically for it because conventional equipment designed for in-center use is not suitable. By starting with a clean sheet of paper and incorporating such features as insitu reuse of the entire extracorporeal circuit, remote telemonitoring, automated system disinfection, and integrated water purification, most of the impediments to performing this modality can be overcome.

Percutaneous translumbar inferior vena cava cannulation for hemodialysis

The purpose of this study was to evaluate the percutaneous translumbar approach for long-term hemodialysis catheter access. Seventeen double-lumen hemodialysis catheters were placed percutaneously from the right flank to the inferior vena cava in 12 patients. Catheter placement was successful in all patients. Adequate flow rates were obtained. Seven episodes of thrombosis-related access failure occurred (0.33 episodes/100 days at risk). Two catheters were removed and five catheters were managed with urokinase infusion. Six episodes of infection occurred (0.28 episodes/100 days at risk). Four required catheter removal. Two catheters were removed after defects developed in the catheter. Five catheters were removed electively because catheter hemodialysis was discontinued. Four catheters remained in place. Cumulative patency was 52% at 6 months and 17% at 12 months. Translumbar inferior vena cava hemodialysis catheters represent a valuable alternative in cases in which traditional catheter sites have failed.

Catheter-related sepsis complicating long-term, tunnelled central venous dialysis catheters: management by guidewire exchange

Standard therapy of catheter-related sepsis of long-term, tunnelled, silicone dialysis catheters is catheter removal, parenteral antibiotics, and catheter replacement in a new venous site after documented clearing of bacteremia. This leads to loss of future venous access sites. Thirteen consecutive cases of dialysis catheter-related sepsis in 10 patients successfully managed by guidewire exchange with preservation of the same central venous access site are reported. Although the most common cause of catheter sepsis in this series was coagulase-negative staphylococcus, guidewire exchange also was successful in cases due to gram-negative rods and yeast. To preserve future venous access sites in the chronic hemodialysis population, long-term, tunnelled dialysis catheter-related sepsis should be managed by a short course of parenteral antibiotics and by changing the catheter over a guidewire using the same venous insertion site.

Technology and clinical application of large-bore and implantable catheters

The access of choice for patients receiving regular dialysis therapy remains the surgically created arteriovenous fistula. In a number of such patients as well as those requiring treatment for acute renal failure, plasmapheresis or hemoperfusion alternative techniques of access are used. Of the techniques used subclavian and femoral catheterization are preferred for short-term vascular access while in patients requiring long term vascular access the use of a surgically inserted central venous line is favoured. The technology performance and clinical aspects of the use of large bore and implantable catheters are reviewed.

Successful use of indwelling cuffed femoral vein catheters in ambulatory hemodialysis patients

Three hemodialysis patients with multiple upper extremity vascular access complications and central vein stenosis were treated for as long as 3 months using an indwelling femoral vein catheter having a buried felt cuff in its subcutaneous tunnel. Four catheters were placed in these three patients. In one case, initial failure due to poor flow and clotting occurred using a straight catheter with its tunnel crossing the inguinal ligament and exiting caudally on the anterior thigh. Otherwise, each patient had successful placement of a 180-degree, curved catheter that exited the femoral vein in the usual fashion but had a subcutaneous tunnel and skin exit pointing cephalad in the inferior portion of the right lower quadrant. The three successful devices functioned immediately after placement, having acceptable outflow pressures and recirculation values. One of three catheters was removed 3 weeks after placement when persisting infection was thought to reside on the device. No other bleeding, thromboembolic, or infectious complications occurred in these patients. In conclusion, short-term indwelling femoral vein access may be feasible in ambulatory hemodialysis patients with previous access difficulties that complicate temporary dialysis treatment.