An approximation method for the prevention of knot formation during catheterization in children

Published:October 08, 2022DOI:



      Knotting during urethral catheterization in children is an unpleasant situation. We aimed to minimize this risk.


      To prevent knot formation, we must understand its nature. We focused on the simplest, and most fundamental, known as overhand knot.


      Calculating the maximum length of catheter inserted in the bladder without risk of knotting, we estimated the minimum length of catheter needed for an overhand knot.


      This theoretical approach provides a rough estimation which may contribute to secure catheterization.


      Adding the calculated length to the appropriate for gender and age urethral length, may reduce knotting risk.


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