Abstract

Intermittent catheterisation is considered as the gold standard for subjects who suffer from urinary retention or incomplete bladder emptying. Essentially two types of male catheter tips are available, a straight tip (Nelaton) and a tapered, curved tip (Coudé or Tiemann). A new omnidirectional, flexible tip has recently been introduced and therefore the navigational properties associated to the various tips of intermittent catheters have been investigated in 9 unselected, fresh, un-embalmed male cadaveric specimens. The hydrophilic catheters were rendered radiopaque through exposure to water soluble contrast media and a <1mm metal piece in the tip. In a randomised fashion the catheters were evaluated with regard to reaching the bladder, ease of insertion and navigational properties. The cadavers (44-88 years old) all displayed some degree of urethral pathology, as expected for this age group. The insertion of catheters with the omnidirectional, flexible tip was in all cases judged as very easy/easy, with no significant difference between them. The fluoroscopic evaluation showed that the omnidirectional properties of the tips were directly translated into smooth less passage of the urethral lumen into the bladder. The conventional catheters did not display such a feature and could in some instances not reach the bladder. The results support the usefulness of flexible catheter tips and future studies in human will disclose whether this mucosal sparing effect has the potential to reduce urethral trauma in subjects in need for intermittent catheterisation.

Keywords: Urinary catheters; Fluoroscopy; Cadaver; Flexible catheter tip, Straight tip; Coudé tip; Tiemann tip; Nelaton; SpeediCath® flex