The relationship between the force applied and perceived by the surgeon during ureteral access sheath placement: ex-vivo experimental model.

To define a peak force of insertion (PFOI) threshold for ureteral damage during ureteral access sheath (UAS) placement on an experimental ureteral orifice model.

A specially designed water tank using 2 laparoscopic 5 mm ports and 2 different size (10 Fr and 8 Fr) sealing cap adaptors (SCA) as ureteral orifices was used to perform the test. A 10-12 Fr UAS was fixed to a load cell and the force of insertion (FOI) was continuously recorded with a digital force gauge.13 experts in the field of endourology who participated performed 3 UAS insertions. The FOI was recorded initially with 10 Fr followed by 8 Fr SCA. On the final insertion, the orifice was obstructed, leaving a 5 cm length to insert the UAS. The experts were asked to "Stop at the point they anticipate ureteral damage, and they would not proceed in real life".

Using 10 Fr SCA the PFOI was 2.12 ± 0.58 Newton (N) (range:1.48-3.48) while 8 Fr SCA showed a PFOI 5.76 ± 0.96 N (range:4.05-7.35). Six of the experts, said they would stop proceeding when they reached above 5.1 N. Three experts had PFOI < 5.1 N and the other 4 stated they would go with PFOIs of 5.88, 6.16, 6.69 and 7.35 N when using SCA of 8 Fr.The highest load they would stop proceeding had a PFOI of 6.09 ± 1.87 N (range: 2.53-10.74).

The PFOI threshold for ureteral damage inserting UAS of the experts is variable. Although FOI is a subjective perception, experience suggests that ureteral injury may occur at an average of 6.05 N perceived by surgeons' tactile feedback. In-vivo measurement of UAS PFOI may confirm a threshold.

World journal of urology. 2024 May 16*** epublish ***

Tzevat Tefik, Rifat Burak Ergül, Palle Osther, Guido Giusti, Glenn M Preminger, Michael Straub, Jens Jochen Rassweiler, Emanuele Montanari, Marianne Brehmer, Christian Seitz, Michael Grasso, Margaret Pearle, Silvia Proietti, Jonathan Cloutier, MGuven Gunver, Ismet Nane, Faruk Ozcan, Olivier Traxer

Department of Urology, Istanbul University Istanbul Faculty of Medicine, Istanbul, Turkey. ., Department of Urology, Istanbul University Istanbul Faculty of Medicine, Istanbul, Turkey., Department of Urology, Urological Research Center, Lillebælt Hospital, University Hospital of Southern Denmark, Vejle, Denmark., Department of Urology, IRCCS San Raffaele Hospital, Milan, Italy., Department of Urology, Duke University Medical Center, Durham, USA., Department of Urology, Technical University Munich, Munich, Germany., Department for Urology and Andrology, Danube Private University, Krems, Austria., Department of Urology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy., Department of Urology, Stockholm South General Hospital Stockholm, Karolinska Institutet, Stockholm, Sweden., Department of Urology, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria., Department of Urology, Phelps Hospital/Northwell Health, New York, USA., UT Southwestern Medical Center, Dallas, TX, USA., Progress in Endourology, Technology and Research Association (PETRA), Paris, France., Department of Medical Statistics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.