# Comparative Analysis Between Insulated Gel Bags and Direct Cooling for Temperature Management During Kidney Transplant Vascular Anastomosis

## TL;DR

This study compares two cooling methods for kidney transplants and finds that an insulated gel bag maintains better temperature control during surgery without affecting short-term kidney function.

## Contribution

The study is the first to compare renal temperature changes between the Organ Pocket® and conventional cooling methods during kidney transplantation.

## Key findings

- The Organ Pocket® group had significantly higher renal surface temperatures during vascular anastomosis compared to the control group.
- Short-term renal function outcomes were comparable between the two groups.
- The Organ Pocket® may improve surgical efficiency and is beneficial in robot-assisted kidney transplantation.

## Abstract

Background/Objectives: Ischemic time plays a crucial role in graft function and survival during kidney transplantation. Cooling methods, including cold perfusion and ice slush, are predominantly applied to preserve the kidney, but they may cause uneven cooling and complications. The Organ Pocket®, an insulated gel bag, has been introduced as an alternative cooling method. However, no studies have compared renal temperature changes between the Organ Pocket® and conventional cooling methods. Methods: We retrospectively analyzed 49 cases of living-donor kidney transplantation. Among these, 33 received kidney grafts preserved with the Organ Pocket® (OP group), and 16 underwent conventional cooling (control group). Renal surface temperatures were recorded at 5 min intervals during vascular anastomosis using thermography. Postoperative renal function was assessed with estimated glomerular filtration rate (eGFR), serum creatinine (sCr), and liver-type fatty acid-binding protein (L-FABP) levels. Results: The OP group demonstrated significantly higher renal surface temperatures than the control group during vascular anastomosis (p < 0.05). Renal surface temperature before reperfusion was 20.4 °C ± 2.5 °C and 17.2 °C ± 2.5 °C in the OP and control groups, respectively. No significant differences in postoperative eGFR, sCr, and L-FABP levels; delayed graft function (DGF); or acute rejection rates were observed between the groups. Conclusions: The Organ Pocket® effectively stabilized renal temperatures during vascular anastomosis without direct cooling, thereby reducing continuous manual cooling requirements. Short-term renal function outcomes were comparable between groups; however, the Organ Pocket® may improve surgical efficiency and be particularly beneficial in robot-assisted kidney transplantation. Further studies are warranted to investigate its long-term benefits.