Percutaneous nephrostomy catheters: drainage flow and retention strength.

Objectives: To evaluate the impact of percutaneous nephrostomy catheter configuration on drainage flow and retention strength.

Methods: The Cook nephrostomy 16F (symmetric balloon), Bardex Council 16F (eccentric balloon), Microvasive Flexima 14F (pigtail), and Bardex Malecot 16F (flange) nephrostomy catheters were attached to an artificial renal pelvis (12-in.-round latex balloon). The balloon was subsequently filled with either 60 mL of water or orange juice with pulp, and gravity drainage of this fluid was recorded as flow into a flowmeter. Using a Force Five Model FDV-100 force gauge, the retention strength was tested by measuring the force required to pull the nephrostomy catheter through an 8-mm hole in a 35-mm-thick biologic tissue specimen (bologna).

Results: The maximal flow rate using both orange juice and saline was significantly greater for the Cook nephrostomy than for the Microvasive Flexima, Bardex Malecot, and Bardex Council catheters (P < or = 0.016). The average flow rate using saline for the Cook nephrostomy catheter was significantly greater than for all other catheters (P < or = 0.02) and was significantly greater than for the Microvasive Flexima and the Bardex Council catheters (P < or = 0.036) using orange juice. The retention strength was strongest for the Cook nephrostomy catheter (3.41 +/- 0.14 lb) compared with the Bardex Council (1.75 +/- 0.1), Microvasive Flexima (1.35 +/- 0.3), and Bardex Malecot (0.29 +/- 0.03) catheters. In addition, the Microvasive Flexima catheter resulted in greater maceration of the biologic tissue after forceful dislodgement.

Conclusions: The results of this study have demonstrated that the Cook nephrostomy catheter combines strong drainage flow and strong retention strength during in vitro testing. Clinical evaluations of the ease of use and patient comfort are warranted.