Comparative study of percutaneous nephrostomy using catheters with and without locking strings

Background: Although it is generally felt that a catheter with a locking string can achieve better fixation and thus prevent catheter displacement, no formal study has ever substantiated this. Methods: We retrospectively reviewed the charts from 80 patients (mean age of 64.6 ± 14.76 y) who underwent percutaneous nephrostomy (PCN) over a 1-year period. Results: Most patients had catheters without locking strings and only 17 patients (21.3%) had catheters with locking strings. The median duration of catheter placement was 29 days (interquartile range 14 - 57 d). There were no significant differences in patients' characteristics or catheter outcomes between catheters with and catheters without locking strings (p > 0.05). In addition, no significant difference in the catheter 90-day survival between catheter types was found (log rank test, p = 0.638). On univariate analysis, tumor as an indication for PCN (p = 0.018), obstruction (p = 0.021) and displacement (p = 0.007) were associated with reduced catheter survival. The multivariate analysis indicated that tumor as an indication for PCN (HR: 0.28, 95% CI: 0.13 - 0.63, p = 0.002), obstruction (HR: 0.25, 95% CI: 0.08 - 0.77, p = 0.015) and catheter displacement (HR: 0.09, 95% CI: 0.03 - 0.31, p < 0.001) were independent hazard factors for reduced catheter 90-day survival. Conclusion: No significant difference in either complication rate or 90-day survival was found between catheters with or without locking strings. These findings may prove helpful to the clinician in deciding the type of catheter to use during PCN.