Hydrostatic pressure gradient ultrafiltration device: A novel approach for extracellular fluids removal

Background: Diuretic therapies aiming to enhance fluid removal in chronic heart failure are limited by kidney function, high central venous pressure, and cardiorenal syndrome. Dialysis and ultrafiltration are associated with multiple visits of the patient in dedicated centres. We suggest a novel approach, in which a permeable absorption chamber is implanted intraperitoneally. A negative hydrostatic pressure in the absorption chamber is induced by a pump, prompting fluids ultrafiltration through the peritoneal membranes into the chamber. The accumulated extracellular fluids are drained to the urinary system. To examine the feasibility of this concept, we implanted an absorption chamber in the peritoneum of rats and drained fluids through the implanted chamber.

Methods and Results: An absorption chamber was prepared from a stainless steel coil with a diameter of 0.4 cm and lengths of 3-6 cm covered by a collagen membrane. The absorption chamber was implanted in the peritoneum cavity of four Sprague-Dawley rats. Two weeks post implantation the rats were anaesthetised and venflon needle was inserted to the chamber. Extracellular fluid were drained from the chamber at an average rate of 16 ± 6 cc/kg/day during 3 hours of intermittent hydrostatic vacuum induction. The fluids electrolytes and proteins were comparable to the serum content.

Conclusions: Implantable absorption chamber enables systemic extracellular fluids removal through the peritoneal membranes. More broadly, this study suggests that an implantable absorption chamber may be used in fluids overload clinical conditions, providing possible future novel heart failure therapy, which is developed nowadays by the authors.