The Impact of Seasonality on Prosthetic Arteriovenous Vascular Access Graft Thrombosis

Highlights Abstract Introduction: Arteriovenous prosthetic grafts are susceptible to recurrent thrombotic occlusions mainly due to venous outflow disease secondary to neointimal hyperplasia. Maintenance of vascular access for dialysis is a perpetual challenge for both patients and health care systems. In regions with hotter climates, there is a clinical impression that episodes of prosthetic arteriovenous vascular access graft thrombosis are more frequent during hot dry summers secondary to dehydration and increased blood viscosity. Seasonality of thrombotic events has been observed in multiple vascular beds. However, a seasonal pattern or any association of arteriovenous graft thrombosis with temperature and relative humidity levels has never been fully demonstrated. Methods: Data were collected prospectively from January 2014 until December 2020 but analyzed retrospectively. In this 7-year timeframe, 289 episodes of arteriovenous graft thrombosis were identified from 142 grafts fashioned. Results: No monthly variation (P = 0.35) or seasonal variation (P = 0.91) was identified. No statistically significant correlation between episodes of thrombosis and mean monthly temperature and mean relative humidity was noted. Conclusion: No evidence was identified to support this theory. However, multiple issues with assessments of events must be conceded. Graft thrombosis is multifactorial in nature, and venous outflow disease contributes toward a significant number of these events. Within our local cohort, a low primary patency rate was identified, which further contributes to graft interventions. Relatively small numbers were recruited, and therefore, potential correlations could have been missed.

Dialysis access graft occlusion with contrast and ultrasound guided thrombin injection for intractable arm edema and pseudoaneurysm

We present the case of a patient with a brachio-basilic graft forearm loop with intractable edema and thrombosed central veins. She showed up with an important edema after some effort and a previously thrombosed pseudoaneurysm with significant growth. She refused angioplasty treatment for central veins, the graft had not been used for dialysis during the last year, so that arteriovenous graft (AVG) ligation was considered. Due to local conditions thrombin percutaneous embolization was performed to avoid possible complications of a conventional surgery approach. AVG occlusion was done in 10 min by fluoroscopy and ultrasound guidance. In 24 h the patient was significantly better and after 1 week she had no edema at all. There were no complications and no recanalization was observed after 3 months. Percutaneous thrombin embolization is a safe and effective technique for AVG occlusion in case of intractable arm edema with central vein thrombosis, and most likely to be considered in other situations where arteriovenous graft or fistula ligature is needed.