configuration, curled or straight catheter, on catheter survival and mechanical and ... catheter (Quinton Instrument Company, Seattle, U.S.A.). When a patient.
Peritoneal Dialysis International. Vol. 15, PP 18-21 Printed in Canada All rights reserved
08968608/95 $300 + 00 Copyright © 1995 International Society for Peritoneal Dialysis
COMPARISON OF STRAIGHT AND CURLED TENCKHOFF PERITONEAL DIAL YSIS CATHETERS IMPLANTED BY PERCUTANEOUS TECHNIQUE: A PROSPECTIVE RANDOMIZED STUDY
Palle K. Nielsen, Claus Hemmingsen, Steffen U. Friis, Jorgen Ladefoged, and Klaus Olgaard
Department of Nephrology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
KEY WORDS: Straight Tenckhoff catheter; curled Tenckhoff catheter; catheter survival; catheter com
plications.
have been reported to be associated with lower complication rates (7), even though another study failed to prove this (8). Apart from a recently published study comparing standard straight Tenckhoff catheters with permanently bent Swan neck catheters, both with a straight intra-abdominal segment, which showed no difference in catheter survival or complication rates when implanted by surgical technique (9), the literature lacks controlled prospective studies comparing straight and coil catheters. We therefore performed a prospective randomized study examining the catheter survival of the curled catheter compared to the straight catheter, using the percutaneous technique. METHODS CATHETERS From April 1992 to J uly 1993, 72 consecuti ve patients selected to the continuous ambulatory peritoneal dialysis (CAPD) program were randomized to receive either a single cuff straight Tenckhoff catheter (LPP, Leo Pharmaceutical, Ballerup, Denmark) or a single cuff coil Tenckhoff catheter (Quinton Instrument Company, Seattle, U.S.A.). When a patient was prepared for catheter implantation, the next in a sequentially numbered series of sealed envelopes containing the catheter type in random order was opened. Allocation to the catheter was, therefore, independent of the physician's choice. In case of catheter replacement, the initial randomization was followed. The study was approved by the local ethical committee. CATHETER INSERTION
safe and permanent access to the peritoneal cavity is a prerequisite for successful chronic peritoneal dialysis. Since the introduction of the peritoneal dialysis catheter by Tenckhoff in 1968 ( I ), several different alternatives to the Tenckhoff catheter have been introduced, but the standard straight Tenckhoff catheter is still the most widely used catheter (2,3). Several studies have shown low complication rates and improved cat heter survi val, compared to historic controls, with the permanently bent Swan neck catheter ( 4-6). In addition, coil catheters
A
Correspondence to: P.K. Nielsen, Department of Nephrology P 2131, Rigshospita1et. 9 B1egdamsvej, 2100 Copenhagen 0. Denmark. Received 31 March 1994; accepted 20 June 1994.
The catheters were inserted percutaneously by members of the nephrology staff, and the types of catheters were evenly distributed among the five nephrologists performing the catheter implantations. All patients received premedication of a minor tranquilizer ana morphine; in all cases local anesthesia (lidocaine 1% containing norepinephrine ) was used. A vertical midline incision 2 cm long opened the cutis and then blunt dissection to the
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.Objective: To examine the impact of peritoneal dialysis catheter configuration, curled or straight catheter, on catheter survival and mechanical and infectious complications. .Design: Prospective randomized trial. .Setting: Department of Nephrology of a single university hospital. .Patients: Seventy-two consecutive patients initiating peritoneal dialysis were randomized to receive either a single cuff straight catheter or a single cuff curled catheter, implanted by percutaneous technique. .Results: Significantly higher (p < 0.01) survival rate of the curled as compared to the straight catheter. The difference in catheter survival was due to a significantly higher (p < 0.01) incidence of drainage failure associated with catheter tip migration of the straight catheter than of the curled catheter. No difference in infectious complication between the two types of catheters was seen. Catheter survival at 12 months was 77% for the curled catheter and 36% for the straight catheter. .Conclusion: This study demonstrates superiority of the curled Tenckhoff peritoneal dialysis catheter survival as compared to the straight catheter. This difference in catheter survival is due to the higher displacement rate of the straight catheter .
fascia was performed. The opening to the peritoneal cavity was performed by a trocar (Leo Pharmaceutical, Ballerup, Denmark), with the catheter placed on a blunt stylet. The catheter was placed in the lowest part of the peritoneal cavity, preferentially the fossa ischiorectalis, while retracting the stylet. The catheter placement was assured by x ray and catheter function was tested by infusion of isotonic saline 100 mL for any resistance to inflow and outflow. With the cutaneous end of the catheter placed on a tunneler, the catheter was pulled through the subcutaneous tissue with the tunneler, the cuff was placed subcutaneously 3 -4 cm from the exit site, and the catheter was placed without sutures. No prophylactic antibiotic treatment was given in relation to catheter implantation. Immediately after implantation, low volume (I L) supine intermittent peritoneal dialysis was initiated for 24 hours (60 L) and was continued one day per week for the first 3 -4 weeks after implantation in order to facilitate fibrous incorporation to the dacron cuff before starting CAPD. No patients needed additional hemodialysis. All patients were started on a disconnect CAPD system. P A TIENTS
CATHETER RELATED COMPLICATIONS AND CATHETER SURVIVAL Patients whose only reason for catheter removal was successful transplantation, elective transfer to hemodialysis due to causes other than catheter malfunction, or death from concurrent disease were regarded as lost to follow-up. Drainage failure was defined as inability to drain effluent reliably, even after conservative manoeuvres to restore catheter function such as abdominal massage, ambulation, enema, and clot dislodgement with heparin or urokinase. Tunnel or exit-site infection was defined clinically as an inflammation, with or without discharge. Initial antibiotic regimen was oral flucloxacillin. modified depending on culture; in case of prolonged infection (more than three weeks) with Staphylocaccus, flucloxacillin was substituted for
RESULTS Patient characteristics are shown in Table 1. N o differences between the two study groups were found. The cumulative time for catheter use was 231 patient-months for the straight catheters and 250 patient-months for the curled catheter, with a mean observation time of 6.0 (0 -14) and 6.3 (1 -15)
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Patient characteristics of the two groups are shown in Table I. No difference between the groups was found. Patients' medical histories are shown in Table 2. No patients had previously received renal replacement therapy. After allocation there were no differences in azotemic levels, number of patients with abdominal surgery prior to catheter implantation, nor in skin status at the time of catheter implantation. The study was designed to include 120 patients, with an evaluation of the results after inclusion of 60 patients in the study and no minimum period of follow-up built into this analysis. Due to significant difference in catheter outcome the study was terminated after inclusion of 72 patients, 34 allocated to curled catheters and 38 to straight catheters.
rifampicin. Peritonitis was defined as two criteria present out of a possible four: 1) cloudy effluent; 2) abdominal pain; 3) leukocyte count above 100 x 106/ L (>50% neutrophils); 4) positive culture. Standard antibiotic regimen was netilmycin and vancomycin each exchange, modified depending on culture and sensitivity. The catheter was removed only in case of resistance to antibiotic treatment. Leakage of dialysis fluid, either external around the catheter or internal into subcutaneous tissue, was treated with supine low-volume dialysis or temporary discontinuation; other complications registered were placement in the bladder and damage to the catheter. We calculated the actuarial catheter survival of the first catheter implanted using the Kaplan-Meier estimate ( 10). Statistical analysis was performed on life-table constructions using log rank test for comparison between the two catheter types. Chi-square test for statistical analysis was performed to examine the difference between the groups at the end of the observation period. A p value less than 0.025 was considered significant.
initially included in the study were able to continue in the PD program with a functioning peritoneal dialysis catheter, while 94% of the patients receiving only curled catheters continued in the PD program with a functioning peritoneal dialysis catheter. Life-table analysis comparing the two types of catheters resulted in a significantly higher (p < 0.0 I ) survival rate for the curled, as compared to the straight, catheter (Figure I ). DISCUSSION The present prospective randomized study comparing straight and curled peritoneal dialysis catheters implanted by percutaneous technique showed a significantly higher survival rate for the curled than for the straight catheter. Previous retrospective reports have shown results in accordance with those of the present study (7) but, to date, there has been no controlled study demonstrating the superiority of one catheter over the other. One recently published prospective randomized study (9) comparing Swan neck and standard straight Tenckhoff catheters, both with a straight intra-abdominal segment and placed by surgical technique, did not show any difference in catheter survival. Drainage failure associated with catheter tip migration was the only complication causing a difference in catheter survival between the two types of catheters. Early drainage failure due to catheter tip migration within the first four weeks after catheter implantation accounted for more than 50% of the catheter loss with the straight catheter. Based upon our own experience with attempts to reposition the catheters by a blunt stylet, we decided not to use this method due to the poor outcome, with a low longterm success rate of only 25%. And, in addition, the procedure was associated with an increased complication rate in the form of leakage and tunnel infections (II). We found no difference in infectious complications and, in addition, no episodes of tunnel
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months, respectively. There was no difference in medical history between the two groups, as shown in Table 2. Complications causing catheter removal of the first implanted catheter are shown in Table 3. We found a significant difference (p < 0.0 I) in the number of catheters with drainage failure, and in all cases we found early drainage failure to occur within the first eight weeks after implantation. The drainage failure was in all cases associated with catheter tip migration. Peritonitis incidence as cause of catheter removal was identical between the two groups. In one case, a curled catheter perforated the bladder and was removed later the same day, and the patient was transferred to hemodialysis. In another case, the cathet er was accidentally removed by the patient: this patient received a second catheter the following day, which functioned throughout the rest of the observation period without complications. In one case, the patient developed a subcutaneous leakage ten weeks after implantation of a straight catheter: the catheter was broken on the inside of the cuff and the abdominal part of the catheter was electively removed later, prior to transplantation. N o other episode of leakage or episodes of exit-site/tunnel infection caused catheter removal. In case of catheter replacement, we found an increasing survival rate for the straight Tenckhoff catheter, resulting in an increasing number of patients being able to continue on the peritoneal dialysis (PD) program (Table 4). After two catheter replacements-if needed-we found that, in the group receiving only straight catheters, 89% of the patients
tion, we could demonstrate a significantly higher survival rate for the curled, compared to the straight, Tenckhoff catheter when placed by percutaneous technique. REFERENCES 1. Tenckhoff H, Schechter HA. Bacteriologically safe peritoneal access device. Trans Am Soc Artif Intern Organs 1968; 14:181-7. 2. Gokal R. Ash SR, Helfrich GB, et al. Peritoneal catheters and exit -site practices: toward optimum peritoneal access. PeTit Dial Int 1993; 13:29-39. 3. Ash S. Chronic peritoneal dialysis catheters: effects of catheter design, materials and location. Seminars in Dialy,sis 1990: 3:39-46. 4. Twardowski ZJ. Nolph KD. Khanna R, Prowant BF, Ryan LP, Nichols WK. The need for a "Swan-neck" permanently bent, arcuate peritoneal dialysis catheter. Perit Dial Bull 1985; 5:219-23. 5. Twardowski ZJ, Prowant BF, Khanna R, Nichols WK, Nolph KD. Long-term experience with Swan neck Missouri catheters. ASAIO Trans 1990: 36:M491-4. 6. Twardowski ZJ, Prowant BF, Nichols WK, Nolph KD, Khanna R. Six-year experience with swan neck catheters. Perit Dial Int 1992; 12:384-9. 7. Swartz R, Messana J, Rocher L, Reynolds J, Starmann B, Lees P. The curled catheter: dependable device for percutaneous peritoneal access. PeTit Dial Int 1990; 10:231-5. 8. Biermann MH. Kasperbauer J, Kusek A. et al. Peritoneal catheter survival and complications in endstage renal disease. PeTit Dial Bull 1985: 5:229-33. 9. Eklund BH. Honkanen EO, Kala A-R. Kyllönen LE. Catheter configuration and outcome in patients on continuous ambulatory peritoneal dialysis: a prospective comparison of two catheters. PeTit Dial Int 1994; 14:70-4. 10. Kaplan EL. Meier P. N on parametric estimation from incomplete observations. J Am Stat Assoc 1958; 53:457-81. 11. Nielsen PK, Hemmingsen C, Ladefoged J, Olgaard K. A consecutive study of 646 peritoneal dialysis catheters. Perit Dial Int 1994; 14:170-2.
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infection or leakage causing catheter removal. In one case, a catheter perforated the bladder and was removed the same day, without causing any complications. Our results with a one-year survival rate of 77% for the curled catheter implanted by percutaneous technique are comparable to the results by surgical implantation of straight catheters (9); the straight catheter placed percutaneously, on the other hand, had a very poor outcome compared to surgical placement. Catheter configuration at the intraperitoneal segment might explain this difference; and, in addition, the surgical method secures a placement of the catheter farther away from the omentum and probably reduces the risk of capture of the catheter by the omentum as compared to the percutaneous technique. The percutaneous technique can be performed as bedside implantation under local anesthesia in the outpatient clinic, whereas the surgical implantation is performed under spinal or general anesthesia. Despite an unacceptably poor outcome after the first implantation of the straight catheter, we found increasing success rates and catheter survival after catheter replace-ment and, for both catheters, we found a success rate of approximately 90% in keeping a peritoneal access with a functioning catheter. The increasing success rates might be due to the fact that the abdominal cavity often contained more than 1 L of PD fluid during the second catheter implantation, in contrast to the first implanted catheter with an empty abdominal cavity, apart from small volumes of ascites. This study demonstrated that the percutaneous implantation of peritoneal dialysis catheters is a dependable method of gaining peritoneal access and that the technique is simple and accessible to nephrology staff, allowing a considerable flexibility in the day-to-day management of chronic renal failure. In conclusion, in this prospective randomized study for the evaluation of catheter performance and outcome in CAPD with respect to catheter configura
