We conducted a technical feasibility and safety study of intraureteric renal negative pressure treatment (rNPT) in patients with chronic kidney disease undergoing elective cardiac surgery with cardiopulmonary bypass

After written informed consent, 10 patients with preoperative estimated glomerular filtration rate of 15 to 59 mL/min per 1.73 m² were enrolled at 3 sites. At the end of surgery, a urologist advanced a specialized ureteral catheter into each renal pelvis under radiographic guidance. Intra.renal negative pressure of −15 mm Hg was initiated postoperatively and continued for 24 hours. Patients were followed up on postoperative days 14 and 28.

Three patients had major protocol deviations with primary catheter misplacement; acute kidney injury developed in 1 of these. Bilateral renal pelvis catheters were deployed per protocol in 7 patients. All patients had microhematuria; 2 had transient hematuria. In the per-protocol group, acute kidney injury developed in 1 patient with stage 4 chronic kidney disease. No patient suffered any other major adverse event. Serum creatinine concentration remained normal in 6 patients at 72 hours; and in 5 patients, estimated glomerular filtration rate had improved from baseline at 28 days.

rNPT is feasible after cardiac surgery. If catheter placement protocol is strictly followed, it is associated with minimal patient risk and potential benefit. A controlled study (NCT07017933) is in progress to evaluate rNPT started before cardiopulmonary bypass and continued postoperatively.