Development of a prognostic model for fistula maturation in patients with advanced renal failure

Abstract

Introduction This study aimed to explore the role of haematological markers and predictive factors on the maturation of arteriovenous fistulae in patients who underwent vascular access surgery at the Royal Infirmary of Edinburgh.

Methods Retrospective analysis of 300 patients was retrieved who had undergone fistula creation between 2006 and 2009. A predictive model was developed using backward stepwise logistic regression. The model discrimination was assessed by the receiver operating characteristics curve and its calibration by the Hosmer and Lemeshow goodness of fit test.

Results Three variables were identified which influenced fistula maturation. Gender - Males were twice as likely to undergo fistula maturation, compared to that of females (odds ratio [OR] 0.514; 95% confidence interval [CI] 0.308 to 0.857). Peripheral Vascular Disease - Patients with no evidence of PVD were three times more likely to mature their fistula (OR 3.140; 95% CI 1.596 to 6.177). Vein Size - A pre operative vein diameter > 2.5mm resulted in a five fold increase in fistula maturation compared to a vein size less than 2.5mm (OR 4.532; 95% CI 2.063 to 9.958). There was a good calibration as indicated by Hosmer and Lemeshow goodness of fit test (P=0.79) and the c-index was 0.677.

Conclusion Gender, PVD and vein size are useful predictors of arteriovenous fistulae maturation. The clinical utility of these risk categories in the maturation of arteriovenous fistulae requires further clinical evaluation in a prospective study.