Improved perioperative outcomes by early unclamping prior to renorrhaphy compared with conventional clamping during robot-assisted partial nephrectomy: a propensity score matching analysis

  • Daisuke MotoyamaEmail author
  • Yuto Matsushita
  • Hiromitsu Watanabe
  • Keita Tamura
  • Toshiki Ito
  • Takayuki Sugiyama
  • Atsushi Otsuka
  • Hideaki Miyake
Original Article


The objective of this study was to evaluate the impact of the early unclamping (EU) technique on perioperative outcomes in patients who underwent robot-assisted partial nephrectomy (RAPN). This study included 96 patients with small renal masses who underwent RAPN performed by a single surgeon using the da Vinci Xi between April 2016 and September 2018. EU and conventional clamping (CC) procedures were defined as those removing the renal artery clamp before and after renorrhaphy, respectively. In this series, contrast-enhanced computed tomography was performed 3–5 days after RAPN to examine the incidence of renal artery pseudoaneurysm (RAP). After adjusting patient variables by 1:1 propensity score matching, 45 patients were included in both the EU and CC groups, and no significant differences in major clinical characteristics were noted between these two groups. Although there was no significant difference in the proportion of patients achieving trifecta or the margin, ischemia and complications score between the two groups, the EU group was significantly superior to the CC group regarding the operative time, console time, warm ischemia time, impairment of renal function 1 day after RAPN, incidence of RAP and postoperative length of hospital stay. Furthermore, RAP occurred in seven patients in the entire cohort (13.3%) receiving CC, including two who required trans-arterial embolization due to severe macrohematuria, whereas RAP was completely prevented by the use of EU. The introduction of the EU technique to RAPN may improve perioperative outcomes, particularly by markedly reducing the risk of RAP even with renorrhaphy.


Robot-assisted partial nephrectomy Renal artery pseudoaneurysm Early unclamping 


Compliance with ethical standards

Conflict of interest

Authors Motoyama, Matsushita, Watanabe, Tamura, Ito, Sugiyama, Otsuka and Miyake declare that they have no conflict of interest.

Ethical standards

All procedures performed in the studies involving human participants were in accordance with the ethical standards of our institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Formal consent from the patients was not required for this study.


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Copyright information

© Springer-Verlag London Ltd., part of Springer Nature 2019

Authors and Affiliations

  • Daisuke Motoyama
    • 1
    Email author
  • Yuto Matsushita
    • 1
  • Hiromitsu Watanabe
    • 1
  • Keita Tamura
    • 1
  • Toshiki Ito
    • 1
  • Takayuki Sugiyama
    • 1
  • Atsushi Otsuka
    • 1
  • Hideaki Miyake
    • 1
  1. 1.Department of UrologyHamamatsu University School of MedicineHamamatsuJapan

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