Long-term peritoneal membrane changes

There is increasing evidence that long-term peritoneal dialysis (PD) is ass ociated with structural changes in the peritoneal membrane. These consist o f thickening of the sub-mesothelial space owing to collagen deposition and alterations in small blood vessel morphology. These alterations become more pronounced with duration of PD therapy. These changes are associated with a tendency to increasing small solute transport rate with reduced ultrafilt ration. The relationship between these structural and functional changes re mains unknown, but the evidence suggests that both peritonitis and exposure to dialysate contribute. The most likely components of the fluid responsib le for this effect are glucose and/or its degradation products generated du ring heat sterilisation. Serial monitoring of peritoneal function is well e stablished, but repeat biopsies are not practical. Effluent markers are not yet of proven value but do alter in response to a change in dialysate comp osition. Hopefully, a combination of reduced inflammation and more biocompa tible fluids will reduce long-term changes in peritoneal membrane structure and function with a consequent improvement in patient and technique surviv al. (C) 2000 by the National Kidney Foundation, Inc.