Experimental evaluation of drainage properties of polymer stents under mechanical compression. Standard and tandem stenting

Mamaev I.E., Glinin K.I., Kotov S.V.

1) FGAOU VO N.I. Pirogov Russian National Research Medical University of the Ministry of Health of Russia, Moscow, Russia; 2) GBUZ “Moscow City Clinical Hospital named after V.M. Buyanov”, Moscow, Russia

Aim. To assess the resistance to the mechanical compression of single and tandem stents.
Materials and methods. An in vitro model of the ureter using a silicone tube connecting the proximal and distal reservoirs was assembled. The proximal reservoir was sealed and connected to a pressure gauge. Stents were placed sequentially in the lumen of the tube. A part of the model of ureter was passed through a compression platform which had a length of 4 cm, a bending angle of 35–40° and the ability to apply variable pressure. Five different 7 Ch polymer ureteral stents were tested in single and tandem manner. The compression force was applied and measured at the level of the compression platform. A criterion of stent failure was an increase of the pressure in proximal reservoir over 20 cm H2O with irrigation of saline at a rate of 30 ml/hour.
Results. Measurements were performed in 11 variants, including without a stent, with single stent (5) and with tandem stents (5). Polyurethane stents showed the least resistance to mechanical compression. In case of tandem stenting, all stents demonstrated an increase in resistance to compression compared to a single stent.
Conclusions. Polymer stents are more resistant to mechanical compression compared to polyurethane ones. Tandem stenting can be an effective tool to counteract the compression by the tumor.

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About the Authors

Corresponding author: I.E. Mamaev – assistant professor of the Department of Urology of FGAOU VO N.I. Pirogov Russian National Research Medical University of the Ministry of Health of Russia, Moscow, Russia, e-mail: dr.mamaev@mail.ru

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