CLOSE MENU
Student’s reassessment of flawed analysis has broad implications for standards of care for kidney disease patients
Hemodialysis is required to cleanse the blood of CKD patients, but it can cause life-threatening complications. A recent meta-analysis by Ravani et al. came to the surprising conclusion that there was no significant benefit to active monitoring and surgical intervention upon first sign of complications. Dr. Raimann and colleagues re-visited this meta-analysis and found it was compromised by a data entry error and by failure to account for differences in the importance of pre-emptive surgical intervention between the two commonly used methods for accessing the blood stream for hemodialysis.
For maintenance hemodialysis over protracted periods of time permanent arteriovenous accesses to the circulatory system are required. The most commonly used access is the arteriovenous fistula which is a direct surgically created connection between an artery and a vein, followed in prevalence by the arteriovenous graft which is a connection of an artery and a vein with prosthetic material (either synthetic or autologous). Unfortunately, both fistulas and grafts are often presenting with complications differing in nature and timing in reference to its creation, both aspects notably characteristically differing between accesses. “For this very reason it was surprising to us that a recent meta-analysis had pooled both and investigated, based on data from 10 prospective trials, the effect of preemptive surgical access correction (surgical intervention upon first sign of complication) compared to deferred care (standard of care with intervention only when some predefined criteria are met or hemodialysis is no longer feasible with the access) on the relative risk of losing the access altogether (requiring the creation of an entirely new access). Even more surprising the authors reported no significant differences between both approaches,” explains Dr. Raimann.
Dr. Raimann and colleagues revisited the data extraction of the Ravani et al. paper and amended an obvious error that affected the significance of the overall model and also conducted Monte Carlo simulation studies to outline the effect of heterogeneity on the overall results of this study. They found that there was a non-significant protective benefit of 13% conferred by preemptive correction on loss of arteriovenous grafts and a remarkable beneficial effect on arteriovenous fistulas (halving the risk of loss compared to standard of care).
“Our findings have implications for the standard of care of more than 400,000 CKD patients in the United States,” explains Dr. Raimann. “In contrast to the conclusions of Ravani et al. we think it is evident based on these data that preemptive correction has a substantial positive effect on the risk of access loss in hemodialysis patients and given the potentially deleterious consequences of losing the access, the dialysis community should not hesitate to opt for a preemptive correction approach.”