Novel Approach to Treating Kidney Insufficiency: Mild Controlled Negative Pressure Treatment (rNPT) at the Renal Pelvis

Background: Many treatments that aim to improve kidney function and volume overload (VO) interfere with renal selective reabsorption and volume and electrolyte homeostasis. This disruption and its sequelae can be avoided via modification of intrarenal hydrostatic forces. One such method utilizes specially designed ureter catheters to deliver rNPT. Controlled negative pressure treatment at the renal pelvis offers a compelling option to sustain and enhance kidney function without blocking vital reabsorptive transport. Methods: Healthy swine (n=16) received bilateral rNPT catheters. Control group (n=8) received no negative pressure. Treatment group (n=8) received -15mmHg rNPT for 24 hours. Both groups were measured for CrCl, UO, RPF, Na+ and K+ excretion, and kidney injury biomarkers. Results: rNPT increased all measures of kidney function including Na+ and K+ excretion (non-significant) without elevating KIM-1, NGAL or histological injury markers. Conclusion: This study in healthy animals highlights rNPT mechanism to preserve renal function and selective reabsorption. Previous studies demonstrate compelling efficacy of rNPT to enhance renal function in cases of prior renal insufficiency and VO. rNPT significantly improved CrCl, UO and Na+ excretion in VO swine (Rao et al, AJP, 2021) and in a US clinical trial in cardiorenal syndrome (VOID-HF, Parker, ASAIO, 2025). rNPT also shows renoprotective effects to prevent post-surgical AKI. rNPT reduced perioperative renal hypoxia incidence in cardiopulmonary bypass (CPB) swine model (Stafford-Smith et al, AKI and CRRT abst #111, 2025). rNPT prevented post-surgical serum Cr rise in a European cardiac surgery clinical trial with CPB and prior renal insufficiency (BIPASS, Washington et al, AKI and CRRT abst #73, 2025). In conclusion, rNPT appears to safely sustain and enhance kidney function while preserving renal autoregulatory mechanisms. Funding: Commercial Support - 3ive Labs, LLCFigure 1. GFR and Renal Plasma Flow