Polyurethane Catheters for Long-Term Hemodialysis Access

Abstract: 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.     

Central venous dialysis access: experience with a dual-lumen, silicone rubber catheter

The central venous dialysis catheter has gained wide acceptance for short-term hemodialysis with the realization of the need to spare peripheral extremity vessels for the creation of more durable internal arteriovenous fistulas. The Hemocath (Quinton Instrument Co., Seattle, Wash.), a soft, silicone rubber, double-lumen central venous dialysis catheter, was introduced as a permanent access device in 1984. A prospective evaluation of 53 catheters placed in 51 patients over a 9-month period is presented. Forty-nine catheters were placed for temporary access and four were placed for permanent access. All 53 catheters were discontinued after functioning an average of 63.9 days (range, 5 to 324 days). No major complications occurred during insertion or on dialysis. One catheter fragmented during removal and was retrieved in the operating room. Infection led to the removal of 17 catheters (34.7%). Thrombosis occurred in 11 catheters and was the cause of removal in two (4.1%). Excluding the two catheters that functioned at the time of the patient's deaths and those placed for permanent access, 91.5% of the catheters performed successfully as temporary accesses devices until permanent access sites were available for use. The catheter provided reliable, relatively safe, and easily maintained central venous access for hemodialysis.     

Ultrasound-guided cannulation of the femoral vein for acute hemodialysis access with silicone catheters

The percutaneous femoral approach for temporary central venous hemodialysis access is a mandatory part of patient management in many clinical settings. It is usually achieved with a blind, exter-nal landmark-guided technique. The aim of this study is to evaluate whether an ultrasound technique can improve on the external landmark method. From 1990 to January 2000, cannulation of the femoral vein was performed on 230 patients (125 male, 105 female, mean age 72 years, range 52-95 years) for temporary vascular access for hemodialysis (172 patients with acute renal failure and 58 patients in end-stage renal disease), using landmark localization with semi-rigid, uncuffed catheters. Between January 2000 and February 2001, ultrasound-guided can-nulation of the femoral vein was utilized in 38 patients (20 male, 13 female, mean age 71 , range 55-93 years) for temporary vascular access for hemodialysis (28 patients with acute renal failure and 10 patients in end-stage- renal failure). Uncuffed, dual-lumen silicone catheters were used. Cannulation of the femoral vein was achieved in 100% of cases using ultrasound, and in 87% using the landmark-guided technique. Using ultrasound, puncture of the femoral artery occurred in 2.6% of patients, and hematoma in 0%. Using the 'blind' technique, puncture of the femoral artery occurred in 11.2% of patients, and hematoma in 3.9%. The average catheter dwell time, in accordance with NKF-DOQI guidelines, was 5 days (range 2 - 14 days) for semi-rigid catheters and 45 days (range 5-120 days) for silastic catheters. The number of complications rose significantly in the patients with semi-rigid catheters. In this group, local exit infection occurred in 105 persons (45% of cases), total catheter thrombosis in 46 (20%), bacteriemia in 28 (12%), and phlebitis of the leg in 6 (2.6%). In the group with silicone catheters local exit infection occurred in 4 patients (10 % of cas-es), total catheter thrombosis in 1 (2.6%), bacteriemia in 2 (5.2%) and phlebitis in 0 (0%). The result of the study suggests that ultrasound-guided cannulation of the femoral vein is superior to traditional techniques relying on anatomic landmark; it reduces the numbers of unsuccessful attempts and the possible acute complications of the procedure. We believe that femoral cannulation with modern flexible silicone catheters can be considered as a reliable temporary access, even for extended periods.     

Do AshSplit haemodialysis catheters provide better flow rates in the long term?

BACKGROUND: Recently, interventional radiologists have adopted an increasingly prominent role in the placement and management of hemodialysis catheters, as well as in the research and development of new and better catheters. The purpose of this study was to evaluate the viability and hemodialysis efficiency of the AshSplit catheter and the Permcath catheter. METHODS: 204 consecutive patients requiring radiological insertion of hemodialysis catheters were followed, retrospectively, over a 42-month period. Both hemodialysis catheters were placed using a combination of ultrasonic and fluoroscopic guidance and tunneled appropriately. Information collected included catheter insertion sites, insertion complications, catheter duration, and final outcome. RESULTS: Over the study period of two years, 269 catheters were placed into 204 patients with end stage renal failure. Patients received either an AshSplit (101 patients, 127 catheters) or a Permcath (103 patients, 142 catheters). Vascular access route of choice was the right internal jugular vein (67% AshSplit, 71% Permcath). Insertion complications occurred in 18 patients overall (6.6%), with only 1 requiring further intervention (hemopneumothorax). Flow rates averaged 259 mls/min for AshSplits and 248 mls/min for Permcaths (p < 0.001). Follow-up of catheter viability for 42 months yielded a mean AshSplit catheter duration of 246 days (range 6-932) and 239 days (range 1-1,278) for Permcath (p = 0.46). Reasons for catheter failure and elective catheter removal were similar in both groups; however, Permcaths required significantly more thrombolysis than AshSplits, p < 0.001. CONCLUSION: The AshSplit provides significantly better flow rates and less thrombolysis compared to the Permcath, with similar catheter dwell times.     

Use of permanent dual lumen catheters for long-term haemodialysis.

Permanent dual lumen catheters (PDLC) provide alternative vascular access in patients considered unsuitable for arteriovenous fistula, arteriovenous graft or peritoneal dialysis. Experience with their use for long-term haemodialysis is presented. Between January 1990 and April 1994, 101 catheters were inserted into 63 patients (median age 62 years). A PDLC was the primary vascular access type in 5 patients. Of the first catheters, 70% were inserted percutaneously into the subclavian vein. The median duration of catheter use was 168 days (range 5-1582 days). The overall cumulative observed catheter survival rate was 94% at 6 months, 89% at 1 year and 75% at 4 years following insertion. The major complications were blockage and catheter related infection occurring in 28% and 15% of catheters, respectively. Death and blockage were the commonest reasons for catheter removal. PDLC play a vital role in the provision of access for long-term dialysis and should be considered the access type of choice in patients with limited life expectancy.     

Clinical evaluation of percutaneous insertion and long-term usage of a new cuffed polyurethane catheter for central venous access.

A new, long-term venous access catheter was evaluated in clinical practice and the insertion time, complication rate and prospective follow-up recorded. Fifty novel polyurethane catheters (Cuff-Cath) were inserted in 48 patients, for cytotoxic chemotherapy in 36, long-term total parenteral nutrition in five and miscellaneous indications in seven. All catheters were inserted by a percutaneous technique under local anaesthesia. The mean insertion time was 18 min. There were three insertion complications; failure to cannulate, pneumothorax and malposition. Seven catheters required removal (sepsis in five, subclavian vein thrombosis in two) and one catheter fell out. Total catheter days to date has been 6607 (mean 132, range 18-831 days). Eleven catheters are still in use a mean of 154 days (range 38-490 days) after insertion. Furthermore, a new technique has been described which prevents inadvertent displacement. This new catheter combines the mechanical advantages of polyurethane, together with those of a Dacron cuff. Early results suggest that this catheter may be a useful alternative to silicone catheters of the Hickman/Broviac type for long-term central venous access.     

The use of the internal mammary vein for central venous access

Purpose: To describe the use of the internal mammary vein as an alternative access for central venous catheters.Methods: We performed a retrospective review of patients who underwent placement of central venous catheters via the internal mammary vein. Patient demographics, indication for venous access, technical success, catheter type, dwell time and indication for exchange or removal were recorded.Results: Placement of central venous catheters via the internal mammary vein was attempted in 11 patients including 8 children (4 males, mean age 5.7 years) and 3 adults. The most common indication was parenteral nutrition in patients with intestinal failure (7/11). Initial needle access of the vein was successful in all patients. Catheter placement was successful in 9 and unsuccessful in 2 patients due to occlusion of the superior vena cava. There were no immediate complications. A total of 20 catheters of various sizes (3–14.5 French) and lengths (8–23 cm) were either placed (n = 12) or exchanged (n = 8). The most common indications for catheter exchange were poor function and malposition (7/8). Four catheters were removed for infection and 4 were accidentally removed. The mean dwell time was 141 days (range 0–963 days) per catheter for a total of 2829 catheter days. The total mean dwell time per patient, including primarily placed and exchanged catheters, was 314 days (range 5–963 days).CONCLUSIONS: The internal mammary vein may provide a safe alternative route for patients who have lost their traditional access veins.     

Conversion of temporary hemodialysis catheters to permanent hemodialysis catheters: a retrospective study of catheter exchange versus classic de novo placement

Many clinicians believe that de novo access is required when converting temporary hemodialysis (HD) catheters to long-term or permanent catheters. However, since vascular access sites are at a premium in the dialysis patient, it is important to preserve existing central venous catheters and conserve future access sites. In this retrospective study, data from 94 patients referred to interventional radiology for placement of long-term, tunneled HD catheters between July 2001 and September 2002 were reviewed. The study group consisted of 42 patients in whom the temporary catheter was exchanged for a peel-away sheath and a tunneled catheter inserted using the existing venous access site. The control group included 52 patients who received traditional de novo placement of permanent catheters. Based on available follow-up data, we report a 100% technical success rate, with 72% patency at 30 days in the study group (n = 32; mean age 58 years). By comparison, de novo catheter placement (n = 35; mean age 59 years) yielded a 100% technical success rate, with 83% patency at 30 days. The overall infection rate was 0.30 per 100 catheter-days (total 3036 catheter-days) and 0.36 per 100 catheter-days (total 3295 catheter-days), respectively (chi2 = 0.64, p > or = 0.05). There was no incidence of exit site infection, tunnel infection, or florid sepsis in either group. Likewise, no stenosis or bleeding complication was noted. Thus conversion of a temporary HD catheter to a tunneled catheter using the same venous insertion site is safe, does not increase the risk of infection, and allows conservation of other central venous access sites.     

Prospective evaluation of a Dacron cuffed hemodialysis catheter for prolonged use

Double lumen subclavian venous hemodialysis catheters are in wide use in the United States to provide temporary vascular access. The disadvantages of these catheters include a high infection rate and short use-life (2 to 3 weeks). We evaluated a felt cuffed tunnelled jugular venous hemodialysis catheter (PermCath) to determine its ability to overcome these shortcomings and compared it with standard noncuffed double lumen dialysis catheters. Eighty PermCaths were inserted during this prospective study in patients needing temporary vascular access in excess of 1 month. Median use-life of these catheters was 8 weeks with a use range of 3 weeks to 5.4 months. Only four functioning catheters failed before elective removal. Despite the prolonged use-life there was only one episode of catheter mediated bacteremia. Seven catheters (9%) failed to function immediately after insertion. These failures were caused by catheter kinking in the region of the felt cuff. Thrombosis of the catheter lumen was the most frequent complication (137 episodes) but resolved in over 95% of the instances with urokinase instillation. Exit site infections (23 instances) were successfully treated conservatively. We conclude that the PermCath (Quinton Instrument Co, Seattle) is a safe and reliable new device with a low complication rate and a longer use-life than standard subclavian dialysis catheters. This longer use-life allows more time for maturation of primary arteriovenous (AV) fistulas and Tenckhoff peritoneal dialysis catheters, and provides time for the healing of infected vascular access grafts. Its primary disadvantage is the need for surgical insertion.     

Conversion of temporary hemodialysis catheters to tunneled hemodialysis catheters

PURPOSE: To determine the feasibility and clinical outcomes of conversion of temporary to tunneled hemodialysis catheters using the same venous insertion site. METHODS: Data from 42 patients with existing temporary hemodialysis catheters referred for placement of tunneled hemodialysis catheters were retrospectively reviewed. In these patients, the temporary catheter was exchanged for a peel-away sheath, and a tunneled catheter was inserted using the existing venous access site. Technical success, procedural complications, and clinical outcomes were evaluated. Hemodialysis records were reviewed to assess catheter patency during a 30-day follow-up period. RESULTS: The study group consisted of 20 males and 22 females (mean age: 58 years). All 42 temporary catheters were successfully converted to tunneled hemodialysis catheters without immediate procedure-related complications. Follow-up data were available for 32 patients (total: 3038; median 71 catheter days). Nine catheters were removed for infection, yielding a catheter infection rate of 0.30/100 catheter days; three catheters were removed for blood flow <200 ml/min. 13 patients had catheters removed when catheters were no longer needed. Three patients died with working catheters. The patency rate was 72% at 30 days, with four catheters functioning at the end of the study period. CONCLUSION: Conversion of a temporary hemodialysis catheter to a tunneled hemodialysis catheter using the same venous insertion site is a safe procedure that avoids complications associated with venotomy and allows conservation of other central venous access sites. Patency and infection rates in these catheters are comparable to several studies of catheter exchange and de novo placement of tunneled hemodialysis catheters.     

All currently used measurements of recirculation in blood access by chemical methods are flawed due to intradialytic disequilibrium or recirculation at low flow

Blood flows and recirculations with standard and reversed direction of lines were measured by chemical (urea and creatinine) and ultrasound dilution (saline) methods in 47 chronic hemodialysis patients. Thirty-seven patients had 47 dual-lumen, central vein (CV) catheters: 32 were PermCath (Quinton Instruments Company, Seattle, WA), 6 were Access Cath (MEDCOMP, Harleysville, PA), 3 were Soft Cell PC (Vas Cath, Mississauga, Ontario, Canada) and 6 were SNIJ (experimental catheters). Three of these last catheters had the tip staggered 7 mm, and three had flush tips; PermCath, Access Cath, and Soft Cell PC catheters have the tips staggered 23 to 25 mm. Forty-six catheters were implanted into the superior vena cava/right atrium, and one catheter was implanted through the left saphenous vein into the left iliac vein. The catheters were studied 1 to 31 months after implantation (median, 3.0 months). Ten patients with arteriovenous (AV) graft access were also studied. The stop-flow method was used in catheter dialysis, and the slow-flow method was used to calculate recirculations in AV access dialysis with samples for systemic blood concentrations taken from arterial line both before and after samples from the arterial and venous lines. At 500 mL/min pump speed, actual blood flow was 436+/-18 mL/min (mean+/-SD; range, 407 to 464 mL/min) with standard direction of catheter lines. At 500 mL/min pump speed, the arterial chamber pressure was -330+/-48 mm Hg (mean+/-SD; range, -380 to -225 mm Hg, and the venous chamber pressure was 259+/-48 mm Hg (mean+/-SD; range, 140 to 310 mm Hg). Arterial chamber pressure was less negative, and venous chamber pressure was less positive with SNIJ catheters, which had larger internal diameter (2.1 mm) compared with the other catheters (2.0 mm). Recirculation varied with the catheter design and the location of the catheter tip. In the catheters with tip staggered more than 20 mm and with standard line connection at pump speeds of 50 mL/min and 500 mL/min, recirculations were approximately 1 % and 5%, respectively, when measured by the chemical method. In the same catheters with reversed lines, the recirculations were approximately 5% and 27%, respectively. Inflow failure catheters with reversed lines had similar recirculation values to those of well-functioning catheters with reversed lines. In catheters with tips staggered 7 mm, and with standard connection of lines, recirculations were approximately 3% and 8%, respectively, at pump speeds of 50 and 500 mL/min. With reversed lines, at the same pump speeds, the values were 7% and 12%, respectively. In flush-tip catheters, the recirculation was higher at a 50 mL/min pump speed (approximately 17%) than at a pump speed of 500 mL/min (approximately 13%). The ultrasound dilution method usually gave lower values than the chemical methods, most likely because of overestimation of recirculation by chemical methods. At least triplicate measurements are needed because single measurements by the ultrasound dilution method are associated with substantial variation. We conclude that both currently used methods (stop flow and slow flow) of taking systemic samples for measurements of recirculation by chemical methods are flawed because of disequilibrium and recirculation at low flow.     

A retrospective study of palindrome symmetrical-tip catheters for chronic hemodialysis access in China

Abstract

Hemodialysis catheters remain necessary for long-term vascular access in patients for whom arteriovenous access may be problematic or impossible. Developments in catheter design have improved long-term catheter functionality, and reduced the rate of infection and complications associated with their use. This retrospective study of 284 cases of chronic catheterization in 271 patients treated between 2009 and 2011 using Tal Palindrome? symmetrical-tip (N?=?118) or Quinton? Permcath? step-tip (N?=?166) hemodialysis catheters evaluates the efficacy and the safety of symmetrical-tip dialysis catheters for chronic hemodialysis, compared with a step-tip catheter. Measurements of catheter performance included mean catheter dwell time, incidence of low blood flow, and rates of infection and catheter-related blood stream infection (CRBSI). The symmetrical-tip catheter had a significantly longer mean dwell time compared with the step-tip catheter; 329.4?±?38.1 versus 273.1?±?25.4?d (p?<?0.05). In addition, the rate of occurrence of low blood flow per 1000 catheter days was lower for the symmetrical-tip compared with the step-tip catheter; 1.13 versus 6.86 (p?<?0.01). The symmetrical-tip catheter was also associated with a lower incidence of complications; the rates of infection (0.28 vs. 0.78; p?<?0.01) and CRBSI (0.15 vs. 0.44; p?<?0.01) were lower compared with those for step-tip catheters, and catheter removal occurred less often for the symmetrical-tip catheter (8% vs. 16%; p?<?0.05). The symmetrical-tip hemodialysis catheter was associated with a longer mean dwell time, lower incidence of low blood flow, and lower infection rate compared with the step-tip catheter.     

Use of Permcath (Quinton) catheter in uraemic patients in whom the creation of conventional vascular access for haemodialysis is difficult

During the last 4 years, the Permcath Quinton double-lumen silicone catheter was inserted into the internal jugular vein of 57 uraemic patients with difficulty for creating conventional vascular access for haemodialysis. In 4 patients, with definitive contraindication of conventional vascular access, this catheter still permits haemodialysis after a duration of 8-25 months. In 25 further patients with terminal uraemia, but poor vein system, it allowed the maturation of an arteriovenous fistula after 2-14 months of use. In 17 patients already on chronic haemodialysis, but who lost abruptly their vascular access (15 grafts and 2 arteriovenous fistulae), it allowed a new arteriovenous fistula to mature in 16 cases after a mean duration of 7.3 +/- months. In 5 patients with short life expectancy because of neoplasia, it allowed to dialyse them until their death which occurred after 6.5 +/- 2.2 months. In 6 patients with acute renal failure and haemostasis problems, it allowed to perform not only dialysis, but also plasmapheresis in 3 and parenteral nutrition in 3 other cases. The complications were the following: sepsis (n = 3); episodes of hypocoagulability due to inadvertent injection of heparin stored in the lumen (n = 2), thrombosis of the lumen (n = 3), and insufficient flow (n = 6). In no case these complications prevented continuation of haemodialysis. The catheter had to be removed in 2 cases because of septis and in 1 case because of insufficient flow. In 3 cases the catheter had to be replaced because of thrombosis and in 1 case because of laceration. These complication rates are, however, fewer than those reported in the literature for arteriovenous shunts or rigid subclavian and femoral catheters. The Permcath catheter seems, therefore to be the method of choice for immediated vascular access in patients in whom the creation of conventional vascular access is difficult.     

Implantation of permanent jugular catheters in patients on regular dialysis treatment: ten years' experience

Dual-lumen cuffed central venous catheter proved an important alternative vascular access compared to conventional arteriovenous (Cimino-Brescia) shunt in a selected group of patients on regular dialysis treatment. Typically, these catheters are used as bridging access, until fistula or graft is ready for use, or as permanent access when an arteriovenous fistula or graft is not planned (NKF-DOQI). We conducted a prospective study on IJV permanent catheter insertion and its related earlier and long-term complications. From February 1991 to February 2001 we inserted in 124 patients in end stage renal disease 135 cuffed catheters (130 in the right IJV and 5 in the left IJV), 92 of which were Permcath, 27 Vascath, and 16 Ash-Split. We performed the insertion of catheters by puncturing the IJV under ultrasonographic guid-ance in the lower side of the Sedillot triangle and checking the accurate position of the tip by endocavitary electrocardiography (EC-ECG). The duration of catheter use was from 60 to 1460 days, mean 345 days. The actuarial survival rate at 1 year was 82%, at 2 years 56%, at 3 years 42% and at 4 years 20%. The exit site infection and septicemia rates were 5.2 and 2.86 per 1000 catheter days respectively. Catheter sepsis was implicated in the death of three patients, all of whom had multiple medical problems. Several episodes of thrombosis (6% of dialyses) occurred which required urokinase treatment, and catheter replacement in 12 patients (9.6%). In 3 cases the catheters were displaced and correct repositioning was performed. Two catheters (Ash-Split) were replaced due to accidental damage of the external portion of catheters (alcoholic disinfectant). Catheter tip embolism occurred on one occasion during elective catheter exchange over guide-wire. One of the common problems encountered with cuffed tunneled catheters is poor blood flow, most often secondary to the formation of a fibrin sheath around the lumen. Even if we conducted a non-randomized study, in our experience, the higher rate of malfunctioning catheters was in the group with no anticoagulation therapy. Therefore, we suggest anticoagulation treatment in all patients wearing central vascular catheters with no contraindication. Just one year ago, we followed NKF-DOQI clinical practice guidelines for vascular access that indicated that for patients who have a primary AV fistula maturing, but need im-mediate hemodialysis, tunneled cuffed catheters are the access of choice and the preferred insertion site is the right IJV. Considering recent reports of permanent central venous stenosis or occlusion after IJV can-nulation, currently, our first choice is femoral vein cannulation with smooth silicone rubber catheters, tunneled if long-term utilization is needed (more the 3-4 weeks). In our opinion, the right IJV puncture is to be avoided as much as the venipuncture of arm veins suitable for vascular access placement, particularly the cephalic vein of the non-dominant arm. Our data confirm that permanent venous catheters might rep-resent an effective long-term vascular access for chronic hemodialysis, particularly for older patients with cardiovascular disease and for cancer patients.     

The Incidence of Subclavian Vein Stenosis Using Silicone Catheters for Hemodialysis

Abstract: Complications related to the use of silicone subclavian catheters for hemodialysis were prospectively studied in 21 consecutive patients with acute and chronic renal failure. Between July 1991 and December 1992, 34 double-lumen silicone catheters (Medcomp; 12 French; 20 or 24 cm) were inserted in 21 patients. The mean duration of catheterization was 20 days (range, 2–58 days). Venograms were performed in 16 patients (22 subclavian veins) within 6 months following removal of the catheter. Excluded from angiography were patients whose catheters had been in place less than 1 week or who underwent fewer than 3 dialysis sessions because of minor risk of stenosis. Patients who had ipsilateral repeated catheters were also excluded. Two angiographies showed subclavian vein stenosis, both occurring in the same patient. One showed 50% stenosis with collaterals; one showed 50% stenosis without collaterals. One other complication was a pneumothorax. Catheter thrombosis was observed in 3 patients; catheter sepsis did not occur. We conclude that use of silicone catheters for subclavian cannulation is safe and effective to provide temporary vascular access for acute hemodialysis. The incidence of subclavian vein stenosis is lower compared with polytetrafluoroethylene and polyurethane catheters.     

Clinical trials of the T-fluted (Ash Advantage) peritoneal dialysis catheter

The Ash Advantage is a T-shaped peritoneal catheter with a single transabdominal tube joining to a tube lying against the parietal peritoneum. Segments with long flutes (grooves) serve as fluid ports rather than 1-mm diameter holes. The folded catheter is placed through the expandable Y-TEC Quill positioned peritoneoscopically, similar to the procedure for a conventional Tenckhoff catheter. In a clinical study, we placed 18 Ash Advantage ("Advantage") catheters, 8 in patients with prior hydraulic or infectious complications of Tenckhoff catheters and 10 in patients initiating peritoneal dialysis. Mean follow-up has been 8.4 months. Outflow rate for the Advantage catheters is uniformly higher than for Tenckhoff catheters at 220 +/- 100 mL/min for the first 5 minutes and 145 +/- 72 mL/min for the next 5 minutes, with outflow completed in 6 to 15 minutes. Variation of outflow volumes for similar exchanges in the same patient is +/- 3% to 5%, much less than with Tenckhoff catheters. Four catheters failed after placement, each for a different reason including outflow failure because of preexisting intraperitoneal adhesions, preexisting peritonitis failing to clear, tubing kink during placement, and catheter break after a freak accident. Life-table analysis of the production version of the catheter in study patients and 12 additional unselected patients indicates a 90% survival at 12 months. In long-term use, the fixed position of the cuffs of this catheter may avoid catheter extrusion, pericatheter hernias, and pericatheter leaks. Multiple fluted ports appear to diminish omental attachment. The catheter may be a useful alternative to conventional Tenckhoff catheters in patients at high risk of catheter failure or in standard peritoneal dialysis patients.     

Acute vascular access catheters for haemodialysis: complications limiting technique survival

The use of acute vascular access catheters (AVACs) has facilitated the delivery of haemodialysis to patients lacking functioning access. A review of the experience of a tertiary Australian renal treatment centre, consisting of 205 sequential AVACs in 93 patients, was undertaken over 1 year, to identify issues limiting technique survival. Acute vascular access catheters were inserted as acute dialysis access for patients with chronic renal failure (CRF; 21%), failed grafts or fistulae (18%), acute renal failure (12%), failed chronic ambulatory peritoneal dialysis (CAPD; 8%) or failed prior AVACs (37%). The majority of AVACs were on the right (74%), and the placement site was simple jugular (69%), tunnelled jugular (15%), femoral (12%), or subclavian (4%). During follow up, 198 of 205 AVACs were removed. The mean AVAC survival was superior (P < 0.0001, Fisher's protected least significant difference (PLSD) for tunnelled jugular AVACS (62 +/- 46 (SD) days) compared with simple jugular (20 +/- 19), subclavian (18 +/- 13) and femoral (7 +/- 6). Causes for AVAC removal were: elective (47%), blockage (31%), infection (20%) or cracked catheter (1%). Routine postremoval tip cultures grew coagulase negative Staphylococcus (CNS, 46%), negative culture (33%), methicillin-resistant Staphylococcus aureus (MRSA; 9%), Staphylococcus aureus (9%), Gram-negative rods (1%), Pseudomonas (0.5%) or other uncommon organisms (2%). Blood cultures were drawn through the AVAC in the setting of suspected bacteraemia in 42 of 198 AVACs. Blood cultures were negative in 40%. Positive cultures included Staphylococcus species in 55%: including MRSA (19%), Staphylococcus aureus (29%) and CNS (34%). Rare cultures identified Escherichia coli (2%) or Serratia (2%). Infection and blockage significantly reduced AVAC survival, affecting more than 50% of cases. Approaches to minimize these complications are likely to lead to improved clinical outcomes with AVAC use.     

Mini‐laparoscopic placement of peritoneal dialysis catheter: New technique

Background: Leakage remains a problem with all methods of catheter placement. We describe our experience with a new mini‐laparoscopic technique for catheter placement in patients with end‐stage renal failure. Patients and methods: Between May 2002 and March 2004, 24 patients underwent mini‐laparoscopic placement of peritoneal dialysis catheters. All patients had end‐stage renal failure with difficult vascular access for haemodialysis. There were 11 men and 13 women with a mean age of 51.4 years (range: 18–75 years). Operative time, interval to initiation of successful peritoneal dialysis, postoperative pain management, resumption of diet and postoperative complications were recorded. Results: The mean operative time was 32.3 min (range: 15–40 min). All patients were given a normal diet on the day of surgery. Postoperative pain was controlled with paracetamol tablets three times daily for 2–3 days. The mean hospital stay was 3.2 days (range: 3–4 days). No patients developed leakage either from the ports or around the catheter. Two (8.3%) patients had blockage of the catheter and underwent diagnostic laparoscopy and laparoscopic correction. Two (8.3%) patients had migration of the catheter which required laparoscopic repositioning. The follow‐up range was between 2 and 22 months. Conclusion: Mini‐laparoscopic technique for placement of peritoneal dialysis catheter is unique because it uses only two ports. The catheter is made to exit via a 2 mm port site and does not require specially designed instruments.     

Radiological placement of the AshSplit haemodialysis catheter: a prospective analysis of outcome and complications.

BACKGROUND: The AshSplit catheter has recently been introduced as an alternative permanent tunnelled haemodialysis catheter, combining ease of insertion with good long-term patency and flow rates. METHODS: Data were collected prospectively on all the long-term tunnelled haemodialysis (AshSplit) catheters inserted radiologically between January 1998 and March 1999. Information was obtained regarding the initial insertion, ongoing catheter function and re-intervention up to September 1999. RESULTS: A total of 118 catheters were inserted in 88 patients (50 male), median (range) age 64 (20-86) years. Ultrasound guidance was used routinely and the right internal jugular vein was used in 80 (68%) cases. Initial complications occurred in 14 (11.9%) cases, which included local haemorrhage, carotid artery puncture, and air embolism. Infection occurred in 34% of catheters (2.4/1000 catheter days). Line thrombosis was documented in 20% (1.2/1000 catheter days). Satisfactory mean urea reduction ratio (URR) of 63 was obtained for all catheters. There were 47 re-interventions, mainly for fibrin sheath stripping (34) and/or thrombectomy (25). Total catheter duration was 21600 days with a 1 month cumulative survival of 87% (Kaplan-Meier probability 85%). At the end of the study, 20 (17%) catheters were still functioning, 39 (33%) had been removed electively, and 22 (18%) patients had died with a functioning catheter in situ. Catheter infection was implicated in four deaths. CONCLUSIONS: Radiological insertion of the AshSplit catheter is well tolerated, providing reliable short- and long-term dialysis access. Radiology also has a role in maintaining patency. As with all tunnelled catheters, infection remains a problem.