Aneurysmal Degeneration of the Brachial Artery Following Chronic Arteriovenous Fistula Ligation.

Introduction: Arteriovenous fistulas (AVF) are currently considered to be the best vascular access option for patients with end stage chronic kidney disease requiring haemodialysis. In rare cases of patients with chronic AVF, thrombosis or ligation of the access can lead to the development of brachial artery aneurysms. Despite being uncommon, reports of this phenomenon have arisen in recent decades due to an increase in the number of patients undergoing dialysis worldwide. This case presented with a brachial aneurysm that developed after AVF ligation. Case report: A 62 year old male presented to the emergency department with swelling of the medial aspect of his left arm associated with pain, inflammatory signs, and finger paraesthesia. Swelling had started two months previously but had worsened within the last week. He had history of kidney transplant 20 years ago and a chronic functioning radiocephalic fistula that had not been used since, and which had been ligated in the past year due to the development of venous aneurysms. Physical examination revealed a pulsatile mass in his left arm and absent radial and ulnar pulses, without signs of hand ischaemia. There was significant venous collateralisation of the arm and chest and numbness of the left fingers, suggesting venous and neurological compression. Computed tomography angiography showed a large left brachial artery aneurysm (108 x 87 x 180 mm). The patient underwent aneurysm sac emptying and collateral ligation followed by great saphenous vein interposition, with clinical improvement. Conclusion: The presence of a chronic AVF can lead to progressive changes in the arterial wall. Sudden ligation or thrombosis of a functioning AVF causes increased blood pressure within the artery, which may further contribute to its aneurysmal degeneration. In addition, immunosuppressive therapy following kidney transplant has been described as a synergistic risk factor leading to aneurysm formation. Despite being a rare complication, patients with a chronic AVF should be monitored closely after vascular access ligation.