Gastro cystoplasty and chronic renal failure: An acid-base metabolism study

Purpose: To verify in an experimental model whether gastrocystoplasty may p rotect patients with chronic renal failure from acid loading associated aci dosis a wedge-shaped portion of the middle stomach was used to improve blad der capacity in animals with chronic renal failure. Materials and Methods: An experimental model was used to study 112 adult fe male Wistar rats (EPM-1) weighing between 156 and 259 gm. The animals were randomly assigned to groups, including 41 controls, 24 undergoing five-sixt hs nephrectomy to create chronic renal failure, 26 undergoing gastrocystopl asty and 21 undergoing gastrocystoplasty and five-sixths nephrectomy to cre ate renal failure. To provide an acid overload a 5% NH4Cl diet was administ ered to a subgroup of each group. Two months after surgery 24-hour urine wa s collected, and volume and pH were measured as well as the amount of bicar bonate, ammonium, titratable acidity and chloride. The animals were then ex sanguinated through an abdominal aorta puncture. The blood was used for blo od gas analysis and to measure sodium, potassium, chloride, ionized calcium and creatinine. Results: When undergoing an acid overload, the animals with gastrocystoplas ty had no acidosis since acid radicals were eliminating in the urine as NH4 Cl. When given the same acid overload, metabolic acidosis developed in the animals with gastrocystoplasty and chronic renal failure. Conclusions: Gastrocystoplasty protected healthy rats from acidosis when th ey were given an acid overload but failed to protect the rats with chronic renal failure under the same conditions.