The Self-Locating Catheter: Review and Cost Analysis

Magnetic Resonance Visibility, Artifacts, and Overall Safety of the Self-Locating Peritoneal Dialysis Catheter with a Tungsten Tip

Background

The self-locating peritoneal dialysis (PD) catheter, contains a tungsten tip. The effects of magnetic resonance (MR) on the catheter were evaluated, emphasizing its MR signal, artifacts, ferromagnetism, and possible heating production during the MR sequences.

Methods

The catheter was studied in an ex vivo model using a 1.5T MR system and placed into a plastic box containing saline solution. Acquisitions on coronal and axial planes were obtained on fast gradient-echo T1-weighted and fast spin-echo T2-weighted. In vivo abdominal MR exams were also carried out.

Results

Overall, the catheter had good visibility. In all sequences, an extensive paramagnetic blooming artifact was detected at the level of the tip tungsten ballast, with a circular artifact of 5 cm in diameter. The catheter showed no magnetic deflection, rotation, or movements during all MR sequences. After imaging, the temperature of the saline solution did not change compared to the basal measurement. Patients safely underwent abdominal MR.

Conclusions

The results point to the possibility of safely performing MR in PD patients carrying the self-locating catheter. The self-locating PD catheter is stable when subjected to a 1.5T MR system. However, it creates some visual interference, preventing an accurate study of the tissues surrounding the tungsten tip.

Influence of peritoneal dialysis catheter type on complications and long-term outcomes: an updated systematic review and meta-analysis

BACKGROUND

There is currently no consensus regarding the optimal type of peritoneal dialysis catheter (PDC). We compared the outcomes of PDCs according to the number of cuffs, intercuff and intraperitoneal segment shape, and presence of a weighted tip.

METHODS

A systematic review of the literature was performed using the MEDLINE and Cochrane Library databases (end-of-search date: October 16th, 2019). We included studies comparing double-cuff vs. single-cuff, swan-neck vs. straight-neck, coiled-tip vs. straight-tip, and weighted vs. non-weighted PDCs for the outcomes of interest. We performed meta-analyses using the random-effects model. We assessed the risk of bias using the Newcastle-Ottawa scale and the Cochrane Collaboration's Tool.

RESULTS

In total, 38 studies were identified, of which 20 were randomized controlled trials (RCTs) and 18 were observational studies. No statistically significant differences were detected between double-cuff vs. single-cuff, swan-neck vs. straight-neck, and coiled-tip vs. straight tip PDCs in any of the outcomes of interest. Weighted catheters were associated with significantly lower rates of tunnel infection (relative risk [RR] 0.52, 95% confidence interval [CI] 0.31-0.95, p = 0.03), migration (RR 0.07, 95% CI 0.03-0.16, p < 0.001), drainage failure (RR 0.62, 95% CI 0.39-0.96, p = 0.03), cuff extrusion (RR 0.40, 95% CI 0.21-0.74, p < 0.001), and complication-related removal (RR 0.53, 95% CI 0.44-0.64, p < 0.001).

DISCUSSION

Among the different types of PDCs, weighted catheters result in lower complication rates and superior long-term outcomes compared to non-weighted catheters. Other aspects of the catheter design do not significantly affect PDC outcomes.

PROTOCOL REGISTRATION

PROSPERO 2020 CRD42020158177.

Finding the Right Position: A Three-Year, Single-Center Experience with the “Self-Locating” Catheter

Background

Peritoneal dialysis (PD) catheter displacement is a major cause of dysfunction. Various catheter forms have been designed to improve outcome. One of them is based on the classical Tenckhoff catheter, but includes a small tungsten cylinder at the distal end to optimize location and to prevent dislocations.

Methods

In this retrospective study, we analyzed the functionality and complication profile of the self-locating catheter implanted at our center from November 2005 to September 2008 in our PD program.

Results

Data from 27 self-locating catheters implanted in 25 patients (12 women) were obtained. Patients were followed for up to 30 months (median observation time: 13 months), resulting in a cumulative study period of 357 PD months. A total of 22 complications were identified, including 1 episode of peritonitis per 52 patient–months, 1 tunnel infection, and 1 exit-site infection. The “functional catheter failure incidence rate” was approximately 0.01 catheters per month on PD (or approximately 1 catheter loss per 100 PD months). The catheter survival was 93% at 1 year.

Conclusions

The “self-locating” PD catheter demonstrates low rates of catheter migration and dislocations, and good catheter survival.

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.

Prospective Randomized Study Comparing a Single-Cuff Self-Locating Catheter with a Single-Cuff Straight Tenckhoff Catheter in Peritoneal Dialysis

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OBJECTIVES

Peritoneal dialysis (PD) catheters are critical to the success of the technique. However, few studies provide evidence about which design helps to reduce complications. Self-locating catheters (SLCs) are used to avoid displacement of the catheter tip. The incidence of mechanical and infectious complications and catheter survival rate were assessed in Tenckhoff PD catheters. ♦

DESIGN

The prospective randomized study compared drainage problems in 40 incident PD patients using a single-cuff SLCs and 38 patients using a single-cuff, straight Tenckhoff catheter (TC). ♦

RESULTS

No significant differences were observed in the number of complications in the Pre period (from the insertion of the catheter to the start of the technique); however, the number of complications was lower in the SLC group during Post (p = 0.021) and Total period (p = 0.048). The number of problems related to catheter malfunction for each period: Pre, Post, and Total, was significantly lower with SLCs vs TCs (p = 0.018, p = 0.001 and p = 0.003, respectively). Problems were solved more easily with SLCs, using laxatives, with less need for fluoroscopic placement and no need for surgical replacement, as opposed to the TC group: Pre (not significant), Post (p = 0.007), and Total (p = 0.011).Median survival was 39.6 months (30.9 - 48.3) for SLCs and 30.1 months (22.6 - 37.5) for TCs, which is not a significant difference. However, SLCs have a higher malposition-free survival rate. Multivariate logistic regression models only included the variable "type of catheter" as a predictor of malfunction during the Pre period (odds ratio [OR] = 4.154). The Post period included the variables, "type of catheter" (OR = 7.701) and "age" (OR = 1.047), and the Total period only included the variable "type of catheter" (OR = 4.487), which indicates an increased probability of malfunction with the use of TCs vs SLCs. The variables (gender, previous intra-abdominal surgery, body mass index (BMI) and diabetes mellitus) did not add predictive value to the models (p > 0.05). ♦

CONCLUSION

The study confirms the hypothesis that TCs have more malfunctions and a lower malposition-free survival rate than SLCs, and TCs are considered as the highest risk factor for malfunction during all study periods.

Comparison between the fixation of peritoneal dialysis catheters to the peritoneal wall and the conventional placement technique: clinical experience and follow-up of a new implant technique for peritoneal dialysis catheters

Peritoneal dialysis (PD) catheters often become severely dislocated, which may lead to malfunction. With the aim of preventing this complication, we have developed a simple method of fixing the catheter downwards in the peritoneal cavity (fixation technique), a technique that does not require a laparoscope. Sixteen patients were implanted using the conventional placement technique and 25 patients were implanted using the fixation technique. The location of the catheter tip was classified from grade 1 (downward, normal) to 5 (dislocated). The frequency of dislocation (defined as the extended time and/or decrease in volume when draining the PD solution) was measured for both the fixation technique and conventional placement technique. There was a significant difference in grade between the fixation technique (2.72 ± 1.01) and conventional technique (3.92 ± 1.31). The time until first dislocation was significantly different between the fixation technique (59.3 ± 48.1 days) and conventional technique (8.8 ± 14.6 days). The time until any dislocation was significantly different between the fixation technique (69.2 ± 41.9 days) and conventional technique (12.9 ± 13.7 days). Complications were not significantly different between the fixation technique and conventional technique. The fixation technique appears to be simple, safe, and useful for preventing severe dislocation and for lengthening the time until dislocation in PD patients.

A brief recap of tips and surgical manoeuvres to enhance optimal outcome of surgically placed peritoneal dialysis catheters

Background. Peritoneal dialysis (PD) is an effective option of renal replacement therapy for ESRF, offering advantages over haemodialysis. Peritoneal dialysis catheter (PDC) placement is thought to be the key to successful PD and the economic advantages are lost if a patient switches to HD in the 1st year. This paper is a brief document elaborating a recap of published literature, looking at various surgical tips and manoeuvres to enhance optimal outcome of PDC placement. Methods. A search strategy assessing for access team, preoperative antibiotic prophylaxis, type of catheter, catheter exit site, intraoperative catheter trial, optimal time to commence PD, hernia repairs, number of cuffs, catheter-embedding procedures, rectus sheath tunnelling, laparoscopic fixing, omentopexy, omentectomy, the "Y"-Tec system, resection of epiploic appendages, adhesiolysis, a trained surgeon, and perioperative catheter care protocol was used looking at various databases. Findings. The complications of catheterrelated dysfunction can be reduced with advanced planning of access placement, immaculate surgery, and attention to catheter insertion techniques. Conclusion. The success of a peritoneal dialysis programme depends upon functional and durable long term access to the peritoneal cavity; this depends on placement techniques and competent surgeons and psychosocial support to the patient. The various technical tips and manoeuvres elaborated here should be considered options carried out to improve outcome and reduce catheter dysfunction.