FACTORS PREDICTING OUTCOMES OF UPPER LIMB RADIO-CEPHALIC ARTERIO-VENOUS FISTULA- A PROSPECTIVE OBSERVATIONAL STUDY

Abstract

AIMS AND OBJECTIVES: To study the factors predicting outcomes of upper limb radio-cephalic arterio-venous stula. MATERIALAND METHODS: This was an observational prospective study that included all chronic renal failure patients requiring AV Fistula surgery between June 2018 to December 2019. All patients whose vascular anatomy does not permit the construction of a native AV stula, as detected on preoperative doppler study, were excluded from the study. RESULTS: Out of 120 cases studied, 88 were male, and 32 were females. In males out of 88 cases, 61 cases had successful outcome (69%) and in 27 cases, stula failed (31%). No signicance on the outcome of the AV stula noted related to comorbidities. Mean preoperative radial artery diameter of 2.8 and 1.9 mm was associated with successful and failed stula, respectively. Mean preoperative cephalic vein diameter of 2.2 and 1.9 mm were associated with successful and failed stulae, respectively. Results suggested a threshold PSV of at least 50cm/sec for stula success. A stula diameter of > 0.4 cm and a minimum ow rate of > 58mL/min resulted in a 93% chance that the stula would be adequate versus 28 % if neither of the minimum criteria were met. Mean post-operative cephalic vein diameter 4.24 and 3.28 mm were associated with successful and failed stula, respectively. CONCLUSION: In our study the cephalic vein size, arterial size and ow rate is the predominant factor determining the success of the radio cephalic stula. There is increasing evidence that routine preoperative duplex USG reduces the rate of primary stula failure and unnecessary surgical exploration. Aminimum arterial diameter of 2mm is associated with successful stula formation. Below this diameter, the success of the stula depends on the ability of the artery to dilate. Athreshold for the minimal venous diameter is difcult to establish. But most clinical studies use a value of 2.5mm for AFV.