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

This study explored the concept of a novel intra peritoneal absorption chamber for fluids removal through the peritoneal membranes. Fluid overload is a common & challenging clinical problem in acutely decompensated heart failure patients (ADHF). Normalization of fluid status in ADHF is associated with improved long term prognosis. Diuretic therapy is limited by kidney function and perfusion pressure, while dialysis and ultrafiltration are associated with significant hemodynamic and electrolyte imbalances when performed in the acute settings. We suggest a novel approach, in which a permeable absorption chamber is implanted in the peritoneum. 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 an ex vivo collection system or into 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 transplanted chamber. An absorption chamber was prepared from a stainless steel coil with a diameter of 0.4 cm and a length of 3-6 cm covered by a collagen membrane (Permacol, Medtronic). The absorption chamber was implanted in the peritoneum cavity of four Sprague-Dawley rats. Two weeks post implantation the rats were anaesthetized and a peritoneal 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 negative hydrostatic pressure induction. The fluids electrolytes and proteins were comparable to the serum content. Implantable absorption chamber enables extracellular fluids removal through the peritoneal membranes. This study suggests that an implantable absorption chamber may be used in fluid-overload clinical conditions, and serve as a possible novel heart failure therapy in acute and potentially chronic settings.