World Journal of Urology

, Volume 36, Issue 5, pp 811–817 | Cite as

Micro-ureteroscopy vs. ureteroscopy: effects of miniaturization on renal vascularization and intrapelvic pressure

  • Juan-Pablo Caballero-Romeu
  • Jua-Antonio Galán-Llopis
  • Federico Soria
  • Esther Morcillo-Martín
  • Pablo Caballero-Pérez
  • Alejandro Garcia
  • Julia E. De La Cruz-Conty
  • Jesús Romero-Maroto
Original Article



Ureteroscopy (URS) is related to complications, as fever or postoperative urinary sepsis, due to high intrapelvic pressure (IPP) during the procedure. Micro-ureteroscopy (m-URS) aims to reduce morbidity by miniaturizing the instrument. The objective of this study is to compare IPP and changes in renal haemodynamics, while performing m-URS vs. conventional URS.


A porcine model involving 14 female pigs was used in this experimental study. Two surgeons performed 7 URS (8/9.8 Fr), for 45 min, and 7 m-URS (4.85 Fr), for 60 min, representing a total of 28 procedures in 14 animals. A catheter pressure transducer measured IPP every 5 min. Haemodynamic parameters were evaluated by Doppler ultrasound. The volume of irrigation fluid employed in each procedure was also measured.


The range of average pressures was 5.08–14.1 mmHg in the m-URS group and 6.08–20.64 mmHg in the URS (NS). 30 mmHg of IPP were not reached in 90% of renal units examined with m-URS, as compared to 65% of renal units in the URS group. Mean peak diastolic velocity decreased from 15.93 to 15.22 cm/s (NS) in the URS group and from 19.26 to 12.87 cm/s in the m-URS group (p < 0.01). Mean resistive index increased in both groups (p < 0.01). Irrigation fluid volume used was 485 mL in the m-URS group and 1475 mL in the URS group (p < 0.001).


m-URS requires less saline irrigation volumes than the conventional ureteroscopy and increases renal IPP to a lesser extent.


Ureteroscopy Urolithiasis Ureteral stones Miniaturization Model, animal Minimally invasive surgical procedures 



Intrapelvic pressure




Systemic inflammatory response syndrome


Retrograde intrarenal surgery












Millimeter of mercury




Body mass index




Peak systolic velocity


Peak diastolic velocity


Resistance Index


Mean arterial flow


No significative


Confidence interval


Student’s test


Wilcoxon signed-rank test


European Association of Urology


Author contributions

JPC-R: project development, data collection, and manuscript writing. JAG-L: project development, data collection, and manuscript writing. FS: project development, data collection, and manuscript writing. EM-M: data collection. PC-P: data analysis. JEC-C: data collection. AG-S: manuscript writing. JR-M: manuscript writing.

Compliance with ethical standards

Conflict of interest

Authors received research funds from a public research institute (ISABIAL-FISABIO) and from Presurgy SL.

Ethical approval

The experimental protocol received approval from the Ethics Committee on Animal Experimentation of the Jesús Usón Minimally Invasive Surgery Center (Cáceres), Spain.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Juan-Pablo Caballero-Romeu
    • 1
  • Jua-Antonio Galán-Llopis
    • 1
  • Federico Soria
    • 2
  • Esther Morcillo-Martín
    • 2
  • Pablo Caballero-Pérez
    • 3
  • Alejandro Garcia
    • 4
  • Julia E. De La Cruz-Conty
    • 2
  • Jesús Romero-Maroto
    • 5
    • 6
  1. 1.Urology Department, University Hospital of VinalopóAlicante Institute for Health and Biomedical Research (ISABIAL-FISABIO Foundation)AlicanteSpain
  2. 2.Endoscopy UnitJesús Usón Minimally Invasive Surgery CenterCáceresSpain
  3. 3.Community Nursing, Preventive Medicine and Public Health and History of Science DepartmentUniversity of AlicanteAlicanteSpain
  4. 4.Urology DepartmentElche University General HospitalAlicanteSpain
  5. 5.Urology DepartmentSan Juan University Clinic HospitalAlicanteSpain
  6. 6.Miguel Hernández UniversityAlicanteSpain

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