Step-by-step Development of a Cold Ischemia Device for Open and Robotic-assisted Renal Transplantation

Abstract

Background: Kidney transplantation (KT) is the best renal replacement treatment. The rewarming time is associated with ischemia/reperfusion damage. In both the open (open KT [OKT]) and the robotic (robotic-assisted KT [RAKT]) approaches, ice slush is used to maintain graft temperature (T°) below 20 °C. This may result in nonhomogeneous graft T° maintenance and, particularly during RAKT where the graft is completely inside the abdominal cavity, rises concerns regarding systemic hypothermia.

Objective: To design a cold ischemia device (CID) to maintain a constant and homogeneous low graft T° during surgery.

Design, setting, and participants: In IDEAL phase 0, a CID was developed and tested to determine its cooling effect on the kidney inside a closed system at 37.5 °C, by comparing it with kidney alone versus a gauze-jacket filled with ice slush. The CID was evaluated in pigs undergoing OKT and RAKT, assessing feasibility and adverse reactions. In IDEAL phase 1, the CID was tested in human OKT and RAKT.

Surgical procedure: OKT and RAKT.

Measurements: In all phases, T° was evaluated at scheduled time points.

Results and limitations: In the preliminary tests of IDEAL phase 0, the CID was able to maintain a low graft T° and superiority to other groups (p = 0.002). In the in vivo animal model, the CID maintained a low and constant graft T° in OKT (n = 3) and RAKT (n = 3), with a mean T° at 50 min of 10.8 °C and 14.9 °C, respectively. IDEAL phase 1 demonstrated feasibility of both approaches (OKT, n = 2 and RAKT, n = 3) using the CID, and graft T° never exceeded 20 °C (mean T°: OKT 15.7 °C vs RAKT 18.3 °C). No complications were recorded. The main limitation consists in the low number of participants.

Conclusions: The CID assured a constant low graft T° during rewarming time, in both OKT and RAKT.

Patient summary: A cold ischemia device (CID) is the first step toward a feasible, safe, and reproducible method to maintain a low graft temperature during surgery. The employment of a CID may optimize the functional outcomes.

Keywords: Cold ischemia device; Kidney transplantation; Robotic surgery.