Which numbing drug works best for dialysis access surgery?

This study tests two numbing medicines, ropivacaine and lidocaine, in 40 adults with end-stage kidney disease who need surgery to create a blood vessel connection (fistula) for dialysis. Patients are randomly assigned to receive one of the two drugs during surgery, and neither they nor their surgeons know which one is used. Researchers measure pain levels, surgery time, need for extra pain relief, and how well the fistula works over the next 5 years. The goal is to find which drug provides better pain control and may improve long-term surgical success.