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 \uf001stula.\nMATERIALAND METHODS: This was an observational prospective study that included all chronic renal failure patients requiring AV Fistula\nsurgery between June 2018 to December 2019. All patients whose vascular anatomy does not permit the construction of a native AV \uf001stula, as\ndetected on preoperative doppler study, were excluded from the study.\nRESULTS: 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\n27 cases, \uf001stula failed (31%). No signi\uf001cance on the outcome of the AV \uf001stula noted related to comorbidities. Mean preoperative radial artery\ndiameter of 2.8 and 1.9 mm was associated with successful and failed \uf001stula, respectively. Mean preoperative cephalic vein diameter of 2.2 and 1.9\nmm were associated with successful and failed \uf001stulae, respectively. Results suggested a threshold PSV of at least 50cm/sec for \uf001stula success. A\n\uf001stula diameter of > 0.4 cm and a minimum \uf002ow rate of > 58mL/min resulted in a 93% chance that the \uf001stula would be adequate versus 28 % if\nneither of the minimum criteria were met. Mean post-operative cephalic vein diameter 4.24 and 3.28 mm were associated with successful and failed\n\uf001stula, respectively.\nCONCLUSION: In our study the cephalic vein size, arterial size and \uf002ow rate is the predominant factor determining the success of the radio\ncephalic \uf001stula. There is increasing evidence that routine preoperative duplex USG reduces the rate of primary \uf001stula failure and unnecessary\nsurgical exploration. Aminimum arterial diameter of 2mm is associated with successful \uf001stula formation. Below this diameter, the success of the\n\uf001stula depends on the ability of the artery to dilate. Athreshold for the minimal venous diameter is dif\uf001cult to establish. But most clinical studies use\na value of 2.5mm for AFV.