The role of peritoneal lavage and the prognostic significance of mesothelial cell area in preventing encapsulating peritoneal sclerosis.

BACKGROUND

Severe peritoneal injury and encapsulating peritoneal sclerosis (EPS) as complications of long-term peritoneal dialysis (PD) are issues of concern. The usefulness of peritoneal lavage after withdrawal of PD and the risk factors for EPS have not been addressed until now. Little is known about mesothelial cell area (MCA) in the effluent as a marker of peritoneal injury. In the present study, we investigated the clinical significance of peritoneal lavage after PD withdrawal and tried to clarify the risk factors related to MCA, with the aim of preventing EPS. We also developed an algorithm for the clinical management of long-term PD patients.

METHODS

We assigned 247 PD patients to one of two cohorts after PD withdrawal: a non-lavage group (73 patients) and a lavage group (174 patients). To clarify the risk factors, we studied these potential predictors: PD duration, dialysate-to-plasma ratio of creatinine (D/P Cr) at the time of PD withdrawal, frequency of peritoneal lavage, type of PD or lavage solution, MCA at the time of PD withdrawal ("PD area"), and MCA at the time of peritoneal lavage withdrawal or censoring ("LA area"). Recurrent intestinal obstruction was defined as the main manifestation of EPS. Diagnostic performance and cut-off values were then calculated for the selected risk factors.

RESULTS

The overall incidence of EPS was significantly lower in the lavage group, at 6.9% (5.2% during lavage and 2.5% after lavage), than in the non-lavage group, at 15.1%. The risk factors and cut-off values were PD area (350 µm(2)) and PD duration (78 months) for the non-lavage group; and PD area (350 µm(2)) and LA area (320 µm(2)) for the lavage group. Patients with a PD duration of 78 months or more and a PD area of 350 µm(2) or more were defined as high-risk patients in the non-lavage group (risk ratio: 11.14), and patients with a PD area of 350 µm(2) or more and an LA area of 320 µm(2) or more were defined as high-risk patients in the lavage group (risk ratio: 10.43).

CONCLUSIONS

Peritoneal lavage is effective in reducing the incidence of EPS after PD withdrawal. The PD duration and MCA are significant risk factors, and these markers are useful for classifying patients into low- and high-risk groups for the development of EPS.