Randomized controlled trial of prophylactic repair of hemodialysis arteriovenous graft stenosis

Background. Previous nonrandomized studies suggest that prophylactic repair of hemodialyisis arteriovenous (AV) graft stenosis reduces thrombosis rates and increases cumulative graft survival. The present study is a randomized trial comparing prophylactic repair of AV graft stenosis with repair at the time of thrombosis. Methods. Sixty-four patients with elevated static venous pressure measured in an upper extremity AV graft were randomized to Intervention or Observation. Monthly static venous pressure/systolic blood pressure ratios (SVPR) were determined for all patients throughout the duration of study participation. Patients in the Intervention group underwent angiography and repair of identified stenoses if the monthly SVPR was elevated (greater than or equal to0.4). Patients in the Observation group underwent stenosis repair only in the event of access thrombosis or clinical evidence of access dysfunction. The primary end point was access abandonment. Results. Access abandonment occurred in 14 patients in the Intervention group and 14 patients in the Observation group during the 3.5-year study period. Time to access abandonment did not differ significantly between the treatment groups (hazard ratio for randomization to Intervention 1.75, 95% CI 0.80-3.82, P = 0.16). The proportion of patients with a thrombotic event was greater in the Observation group (72%) than in the Intervention group (44%) (P = 0.04), but overall thrombosis rates were similar in the groups. Conclusion. Compared with a strategy of observation and repair of accesses only in the event of thrombosis, prospective static venous pressure monitoring with prophylactic stenosis repair did not prolong graft survival.