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Nonmaturation of arm arteriovenous fistulas forhemodialysis access: A systematic review of riskfactors and results of early treatmentEduard H. J. Voormolen, BSc,a,b Abdelkarime Khodadade Jahrome, MD,c Lambertus W. Bartels, PhD,bFrans L. Moll, MD, PhD,c Willem P. Mali, MD, PhD,a and Peter J. Blankestijn, MD, PhD,dUtrecht, The NetherlandsIntroduction: Arteriovenous fistula (AVF) nonmaturation increases reliance of hemodialysis patients on grafts andcatheters, exposing them to associated high complication risks. This systematic review assessed the success rates andcomplications of therapeutic interventions in arm hemodialysis AVFs experiencing nonmaturation. It also compared theefficacy of preoperative clinical factors (eg, age, gender, race), and preoperatively and postoperatively acquiredhemodynamicparameters (eg, arterial diameter or blood flow through the AVF) at stratifying risk of nonmaturation.Methods: Two independent researchers used a systematic strategy to search literature databases and extract data fromarticles judged relevant and valid. The evidence base for this review comprised 33 articles, 12 about treatment, and 21concerning risk stratification. A meta-analysis was performed to calculate summary measures for nonmaturationtreatment success and risk stratification efficacy (eg, excess risk and relative risk) of preoperative clinical, preoperativehemodynamic, and postoperative hemodynamic risk factors.Results: The success rate of early endovascular or surgical treatment, defined as the possibility of achieving adequatehemodialysis, averaged 86%, with 1-year primary patencies of 51%, 1-year secondary patencies of 76%, and complicationrates of 9.3%, with 5.5% minor complications. Overall, patients with preoperative clinical risk factors had excessnonmaturation risks of 21% (95% confidence interval [CI], 11%-30%) and a relative risk of 1.7 (95% CI, 1.3-2.1). Patientswith preoperative hemodynamic risk factors had average estimated excess risks of 24% (95% CI, 15%-33%) and a relativerisk of 1.7 (95% CI, 1.4-2.0). Patients with hemodynamic risk factors present shortly after operation had excessnonmaturation risks of 50% (95% CI, 42%-58%) and a relative risk of 4.3 (95% CI, 3.4-5.5).Conclusions: Patients can be treated effectively for AVF nonmaturation early on, and it is possible to identify thosepatients at risk of nonmaturation most effectively with an early postoperative assessment of hemodynamic risk factors.Additional research is needed that concentrates on adopting the strategy of early treatment of patients with postoperativerisk factors. ( J Vasc Surg 2009;49:1325-36.)Meta-analysis• 1794 articles 33 articles with 745 patients fit criteria• Summary measures for risk stratification efficacy• Methodological quality of studies evaluated• Excess risk and relative risk for non-maturation calculated– Excess risk: The difference between the absolutenonmaturation risk of patients considered at risk (ie, patientswith risk factors) and considered not at risk (ie,patientswithout risk factors). A measure of 0% means no risk isconferred by the risk factor.– Relative risk: The nonmaturation risk of a patient at riskdivided by the nonmaturation risk of a patient not at risk. Ameasure of 1.0 means no risk is conferred.Voormolen E. J Vasc Surg 2009Meta-analysis•Methodological quality for most studies was poorRisk FactorsExcess Non-maturationRiskRelative Non-maturationRiskPre-operative Clinical Risk Factors 21% (95% CI, 11%-30%) 1.7 (95% CI, 1.3-2.1)Pre-operative Hemodynamic Factors 24% (95% CI, 15%-33%) 1.7 (95% CI, 1.4-2.0)Post-operative Hemodynamic Factors 50% (95% CI, 42%-58%) 4.3 (95% CI, 3.4-5.5)Voormolen E. J Vasc Surg 200987