2025/10/29 | People | Surgical technologies

PhD Defense: Pedro Pereira Amado Proposes Clean, Long-Lasting and Personalized Ureteral Stent Solutions

On October 29, 2025, Pedro Pereira Amado successfully defended his PhD thesis: "Investigating the interplay between urine flow, crystal deposition, and bacteria to improve the performance of ureteral stents."

In this thesis, Pedro addressed the complications associated with ureteral stents. He performed five studies, combining fluid dynamics, bioinspired design and machine learning to investigate the mechanisms of ureteral stents and propose passive and active strategies to improve their performance and move ureteral stents toward cleaner, longer lasting, and personalized solutions.

Applications of ultrasound-activated ciliary bands (UACBs) for biofilm and encrustation control. Illustration from the paper published in PNAS (see publications below). ©Pedro Pereira Amado

The first study was concerned with the impact of vesicoureteral reflux (VUR)—when urine flows backward toward the kidneys—on encrustation patterns and wall shear stress (WSS). The second study addressed this issue, evaluating the effect of additional side holes (ASHs) at both ends of the stent using computational fluid dynamics.

The third and fourth study were concerned with active cleaning approaches using bioinspired ultrasound-activated ciliary bands (UACBs), for the prevention of encrustation and biofilm in long-term stenting. A fifth study used machine learning to classify and identify risk factors linked to recurrent stone events (RSE) to identify which patients benefit from stent placement and provide personalized stent management and help in the selection of appropriate stent technologies.

Congratulations to Dr. Pedro Pereira Amado on this incredible achievement and moving ureteral stenting toward long-lasting, patient-oriented solutions!

Publications:

Amado, Pedro; Zheng, Shaokai; Burkard, Fiona; Obrist, Dominik; Clavica, Francesco (2025). Rethinking ureteral stent design: Do more side holes improve performance? Computers in Biology and Medicine 196(Part C):110895. Elsevier 10.1016/j.compbiomed.2025.110895

Amado, Pedro; Dillinger, Cornel; Bahou, Chaimae; Hashemi Gheinani, Ali; Obrist, Dominik; Burkhard, Fiona; Ahmed, Daniel; Clavica, Francesco (2025). Ultrasound-activated cilia for biofilm control in indwelling medical devices. Proceedings of the National Academy of Sciences (PNAS) 122(18):e2418938122. National Academy of Sciences 10.1073/pnas.2418938122

Amado, Pedro; Zheng, Shaokai; Lange, Dirk; Carugo, Dario; Waters, Sarah L.; Obrist, Dominik; Burkhard, Fiona; Clavica, Francesco (2024). The interplay between bacterial biofilms, encrustation, and wall shear stress in ureteral stents: a review across scales. Frontiers in Urology 3:1335414. Frontiers 10.3389/fruro.2023.1335414

Zheng, Shaokai; Amado, Pedro; Obrist, Dominik; Burkhard, Fiona; Clavica, Francesco (2022). An in vitro bladder model with physiological dynamics: Vesicoureteral reflux alters stent encrustation pattern. Frontiers in Bioengineering and Biotechnology 10:1028325. Frontiers 10.3389/fbioe.2022.1028325

Zheng, Shaokai; Amado, Pedro; Kiss, Bernhard; Stangl, Fabian; Haeberlin, Andreas; Sidler, Daniel; Obrist, Dominik; Burkard, Fiona; Clavica, Francesco (2022). Quantitative Evaluation of Encrustations in Double-J Ureteral Stents With Micro-Computed Tomography and Semantic Segmentation. Frontiers in Urology 2:836563. Frontiers 10.3389/fruro.2022.836563

Patent:

Dillinger, Cornel; Ahmed, Daniel; Obrist, Dominik; Burkhard, Fiona; Clavica, Francesco; Amado, Pedro Pereira (2024). Medical device for use as ureteral stent, biliary stent or urinary catheter in a human or animal body, medical system comprising such a device and method of acoustically activating such a device. (Patent No. CH000336/2024)