Which is better for kidney preservation, HTK (Histidine-Tryptophan-Ketoglutarate) solution or UW (University of Wisconsin) solution?

UW Solution is Superior to HTK for Kidney Preservation

For kidney preservation, University of Wisconsin (UW) solution is superior to Histidine-Tryptophan-Ketoglutarate (HTK) solution, particularly for longer preservation times, as it results in better graft survival and function. 1

Comparative Effectiveness of UW vs HTK Solutions

• UW solution demonstrates better long-term preservation capabilities compared to HTK solution alone, resulting in significantly better survival rates in transplant models (18.5 days for combined HTK/UW vs. 2.6 days for HTK alone) 1
• UW solution is associated with lower rates of initial non-functioning kidneys (75% for UW vs. 100% for HTK) 1
• UW solution shows better cellular energy conservation with higher tissue ATP/ADP concentrations compared to HTK-only preservation 1
• UW solution results in decreased production of free radicals compared to HTK solution, as measured by lower urine concentrations of isoprostanes (oxidative stress markers) 1

Clinical Outcomes with UW Solution

• Kidneys preserved with UW solution demonstrate more rapid reduction in postoperative serum creatinine compared to Euro-Collins solution 2
• UW solution preservation leads to higher creatinine clearance rates post-transplantation 2
• Patients receiving kidneys preserved in UW solution require less postoperative dialysis (21% vs. 31% with Euro-Collins) 2
• At three months post-transplant, 92.4% of patients with UW-preserved kidneys have functioning grafts compared to 88.4% with Euro-Collins solution 3
• One-year graft function rates are higher with UW solution (88.2% vs. 82.5% with Euro-Collins) 3

Physiological Advantages of UW Solution

• UW solution provides better protection against ischemia-reperfusion injury 1
• UW solution contains hydroxyethyl starch (HES), which contributes to its effectiveness in organ preservation, though the quality of HES may affect outcomes 4
• The electrolyte composition of UW solution appears to be optimized for kidney preservation 4

Combined Approach Considerations

• A combined approach using HTK for initial flush followed by UW for storage may provide the best outcomes, leveraging HTK's low viscosity for initial perfusion and UW's superior preservation properties 1
• This combined approach results in:
  • Better survival rates (18.5 days vs. 13 days for UW alone) 1
  • Lower rates of initial non-functioning kidneys (33% vs. 75% for UW alone) 1
  • Lower oxidative stress markers 1

Cost-Effectiveness Considerations

• Despite the higher initial cost of UW solution compared to alternatives, the improved outcomes make it cost-effective 3
• The extra cost of UW solution (approximately $230 per kidney over Euro-Collins) is offset by reduced healthcare expenditures within three months post-transplant 3
• Long-term savings from using UW solution are estimated at approximately $7,000 per patient, primarily from reduced dialysis requirements 3

Practical Application

• For standard kidney preservation, UW solution should be the primary choice, especially for anticipated longer cold ischemia times 1, 2
• For multi-organ procurement, UW solution is particularly advantageous as it effectively preserves all intra-abdominal organs 2
• When available, consider a combined approach using HTK for initial flush followed by UW for storage to maximize preservation quality 1

In conclusion, while both solutions can be used for kidney preservation, UW solution demonstrates superior outcomes in terms of graft survival, function, and cost-effectiveness, making it the preferred choice for kidney preservation.