Pre-clinical Evaluation of a Variable Length and Conforming Peritoneal Dialysis Catheter Weighted Anchor: In Vitro Analysis and Cadaver Feasibility Study

Abstract

Purpose Peritoneal dialysis (PD) catheters function best when residing within the retrovesical space of the peritoneal cavity, but they frequently migrate and fail. A novel variable length and conforming PD catheter weighted anchor to prevent migration has been evaluated.Methods Test devices were placed in normal saline for 21 months. The effluent was periodically measured for heavy metals, including tungsten. The water-tight property of the device was also tested separately. Four cadavers were subjected to three-dimensional imaging and maneuvering to evaluate percutaneous insertion, function, stability within the retrovesical space, and percutaneous retrievability in 10 test devices.Results Liquid leakage was low, with a mean absorbance of the test device effluent saline of 0.015. Mean methylene blue absorbance of the test device was significantly lower than the positive control (p-value = 0.01). Leakage of tungsten from devices made with medical grade Silastic tubing was also low, with a mean of 0.362 mg/L in the effluent saline, compared to a background concentration of 0.166 mg/L. Each test device was successfully inserted into the retrovesical space and retrieved percutaneously and remained completely intact following placement and insertion. No test device migrated as shown on axial cone beam CT imaging. Mean flow times and volumes were satisfactory at 3 minutes and 0.92L, respectively, for all test devices. For all catheters, the mean flow rate was 312 cc/min. No significant difference was found between the pre-roll and post-roll mean flow rates of the test devices (p-value = 0.35).Conclusion This PD catheter weighted anchor showed stability, with minimal leakage of tungsten. All test devices were successfully inserted and retrieved percutaneously, with no damage or migration, and mean flow rates were satisfactory. Further investigation is warranted.