Medical adjuvant treatment to increase patency of arteriovenous fistulae and grafts.

backgroundEnd Stage Renal Failure (ESRF) patients often require either the formation of an arteriovenous (A-V) fistula or an A-V interposition prosthetic shunt for haemodialysis.

objectivesTo determine the effects of adjuvant drug treatment on the patency of fistulae and shunts in patients with ESRF undergoing haemodialysis by assessing the number of thrombotic episodes. SEARCH STRATEGY: Publications describing (or potentially describing), randomised controlled trials of medical adjuvant treatment of patients with ESRF on haemodialysis via A-V fistula or interposition prosthetic A-V shunt, were sought through electronic searches of the Cochrane Peripheral Vascular Diseases Specialised Trials Register (last searched October 2002), and the Cochrane Central Register of Controlled Trials (CENTRAL) database (last searched Issue 3, 2002). SELECTION CRITERIA: Randomised controlled trials of active drug versus placebo in patients with ESRF undergoing haemodialysis via an A-V fistula or prosthetic interposition A-V shunt. DATA COLLECTION AND ANALYSIS: Two reviewers (ADS, PAR), independently assessed trial quality and three (ADS, XE, PAR) extracted data. Information on adverse events was collected from the trials. The outcome measure analysed was the long term fistula, or shunt patency rate. MAIN

resultsThe overall search identified three randomised controlled trials of aspirin versus placebo with a total number of 173 participants followed up to a maximum of 18 months. The aspirin dosage given was different in each of the trials (325 mg/once daily; 500 mg/once daily; and 160 mg/once daily). The overall result of the meta-analysis favoured treatment with aspirin (Odds Ratio (OR) 0.42, 95% Confidence Interval (CI) 0.20 to 0.86). The overall p-value for the three studies was 0.02. Three ticlopidine (a platelet aggregation inhibitor) versus placebo trials were also identified with a total number of 312 participants. All patients were followed up for one month, and the dose of ticlopidine given was the same for all three studies (250 mg/twice daily). The overall result of the meta-analysis also favoured treatment. (OR = 0.47, 95% CI 0.26 to 0.85). P-value for overall effect was 0.01. One trial in a parallel group design examined the effect of dipyridamole versus placebo, and dipyridamole plus aspirin versus placebo, and followed up patients for eighteen months. The overall result favoured treatment (OR 0.29, 95% CI 0.06 to 1.40) and (OR 0.77, CI 0.19 to 3.19) respectively. REVIEWER'S

conclusionsThe meta-analysis confirmed the beneficial effect of antiplatelet treatment as an adjuvant to increase the patency of A-V fistulae and shunts in the short term.