Renal Division, Department of Internal Medicine, University Hospital, Gent, Belgium
Keywords: peritoneal dialysis catheters; percutaneous implantation; surgical placement
Introduction
Uncomplicated access to the peritoneal cavity using a permanent in-dwelling catheter is a key factor for successful peritoneal dialysis (PD). Since the introduction of the Tenckhoff catheter [1], different catheter designs (arcuate swan neck or not, number of cuffs, straight or curled intraperitoneal part) [24] placement modalities (surgical laparatomy, bedside, laparoscopic) [5], paramedian vs median insicion and different locations of the exit site (abdominal or thoracic) [6] have been proposed to reduce complications. The latter include migrations of the catheter, clotting, exit-site infection, and leakage.
The question what defines a good peritoneal access? has many potential answers. Some clinicians will argue that the long-term reliability regarding flow is most important, others will point to the prevention of exit-site infection and peritonitis, and still others will look at the price or the simplicity and safety of the insertion. Taking into account all these different factors, it becomes clear that the preferred access method does not exist, but that each modality has its pros and cons, and its specific indications.
Catheter design
Concerning catheter design, the two-cuffed, curled Swan-neck catheter seems to have some advantages over the simple, straight Tenckhoff [7]. In a first prospective study where patients were randomized for either a single-cuff straight Tenckhoff catheter or a permanently bent, single-cuff Swan neck catheter, no significant differences in 2-year catheter survival and probability of episodes of peritonitis, or exit-site infections could be demonstrated [8]. However, only 40 patients were enrolled in this study, so these negative results were probably due to the lack of statistical power. In a much larger prospective study, Gadallah et al. [7] examined two similar double-cuff, curled-end catheters: one with a straight segment (group I), and one with a 60° Swan-neck bend (group II) between the two cuffs. All catheters were placed by the closed laparoscopic technique. Where in group I, 33 of the 219 patients (15%) developed catheter migration, in group II only two of the 243 patients (<1%) developed this complication. The authors conclude that the Swan-neck catheter was superior in the prevention of catheter migration. The superior survival of the curled as compared with the straight Tenckhoff PD catheter was demonstrated by Nielsen et al. in a prospective randomized study [9]. Other adaptations of the catheter design have been proposed [3], but none have until now been proven to be superior [10].
Implantation technique
Although no hard evidence exists, it is quite obvious that not only the catheter type per se, but mainly the implantation technique (used method, experience and care of the performer) will have impact on the catheter outcome.
In this issue, Özener et al. [13] report their extensive experience with percutaneous placement of 113 CAPD catheters, and compare that with a historical control group of 82 surgically implanted catheters. Although this publication has the merit of being one with the largest patient numbers on this topic, some remarks have to be made. The fact that the study is retrospective is of minor importance, as data are derived from a database that was prospectively designed, although not specifically for this study. However, as most surgically placed catheters were placed in the first years of the PD programme, it might well be that the catheter survival was more improved by the increased general experience in handling of the PD patient rather than by the catheter insertion method itself. The interpretation of the results is further complicated by the fact that most of the percutaneously placed catheters are of a different type than the surgically placed catheters (curled vs straight). In addition, percutaneous placement was only performed in patients without prior abdominal surgery, and surgical placement was preferred in patients at risk of complications, e.g. very obese patients.
Bearing these remarks in mind, the conclusion of Özener et al. [13] is that percutaneous placement of catheters compares favourably with the surgical technique for both catheter-related mechanical and infectious complications.
Surgical insertion, percutaneous placement using the Seldinger technique as well as peritoneoscopic placement of PD catheters were in the 1988 Official Report of the International Society for Peritoneal Dialysis (ISPD) [11] on peritoneal catheters and exit-site practices all described as accepted techniques with no indication that one technique is superior to the other. However, the committee gives a warning not to perform a blind insertion with a Seldinger technique in obese patients, or in patients in whom intra-abdominal adhesions may be expected because of the increased risk of bowel perforation, early leakage, outflow failure, and infectious complications. The results presented by Özener et al. [13] fit well with these recommendations: in well-defined indications, the blind insertion technique gives very good results. In these patients, the placement of the catheter can be done in an outpatient setting by the nephrologist who has taken care of the pre-end-stage renal disease management. The procedure, which can easily be performed under local anaesthesia increases the commitment between the PD team and the patient, and reduces costs and inconvenience for the patient. In this way, the procedure fits in the integrated care concept, using low-budget techniques in the appropriate settings. Some recommendations, also applying for surgical catheter placement, are however of critical importance for a successful outcome. The bladder should be empty during the procedure, so an indwelling bladder catheter or a pre-procedure bladder catheterization is mandatory. As constipation increases the risk for catheter dislocation and/or malfunctioning, a bowel enema should be advised. The exit site should be marked in the sitting position to avoid the belt line. The procedure should be performed by an experienced nephrologist in a room that is specially designed for catheter placement or that at least ensures a sterile, calm, and quiet environment. Under these conditions, the reported complication rate is rather low. Visceral injury or severe haemorrhage was only seen in 1.5% of cases in the series of Swartz et al. [14], in the study of Özener et al. [13] one wound haematoma occurred and Nielsen et al. [9] reported only one visceral laceration (bladder), an event that resolved after catheter removal. The percutaneous technique results in a very small scar (±2 cm) and no postoperative hospitalization or rehabilitation is requested. The technique is thus quite safe.
In patients where introduction under visualization is warranted, or in patients not willing to accept a procedure under local anaesthesia, placement of the catheter can either be performed by dissection (true surgical) or by peritoneoscopic technique.
As far as we know, there is only one prospective randomized study comparing surgical placement with the peritoneoscopic technique using the Y-TEC system [12]. Gaddalah et al. compared the outcome of 76 patients in whom the PD catheters were placed peritoneoscopically with that of 72 patients who received surgically implanted catheters. Early peritonitis episodes (within 2 weeks of catheter placement) occurred in nine of 72 patients (12.5%) in the surgical group, vs two of 76 patients (2.6%) in the peritoneoscopy group (P=0.02). This higher rate of infection was most likely related to a higher rate of exit-site leaks in the surgical group (11.1%) as compared with the peritoneoscopy group (1.3%). Moreover, peritoneoscopically placed catheters were found to have better survival (77.5% at 12 months, 63% at 24 months, and 51.3% at 36 months) than those placed surgically (62.5% at 12 months, 41.5% at 24 months, and 36% at 36 months) (P=0.02, 0.01, and 0.04), respectively. To our knowledge there is no study comparing the percutaneous Seldinger technique to the Y-TEC system.
The incidence of 1.5% early leakage (2/133) and of 3.16% early infectious complications (5/133) in the percutaneous placement group of Özener et al. [13] is comparable with the complication rate observed with the peritoneoscopic technique [12]. The first and second year catheter survival of Özener's percutaneous series is excellent compared with any other surgical or peritoneoscopic series [11].
Conclusion
The percutaneous catheter implantation technique is a simple procedure, which, however, requires experience and meticulous attention. It is fair to state that in experienced hands percutaneous placement of Tenckhoff catheters is a safe and dependable method for creation of the peritoneal access. This technique is accessible to the nephrologist, saving time and costs and minimizing patient discomfort.
The technique also has, however, its limitations, and cannot be advised for at-risk patients, where surgical or peritoneoscopic placement is the preferred alternative.
Notes
Correspondence and offprint requests to: Norbert Lameire, Renal Division, Department of Internal Medicine, University Hospital, De Pintelaan 185, B-900 Gent, Belgium. Email: isabel.vandorpe{at}mg.ac.be
References