Stridor and Horner's syndrome, weeks after attempted right subclavian vein cannulation

A 23-year-old woman presented with renal failure resulting from polycystic kidney disease (PKD) aggravated by tubulo-interstitial nephritis. Emergency haemodialysis was planned, and cannulation of the right subclavian vein was attempted, but failed. During this procedure, inadvertent arterial puncture occurred. Transient mild ischaemia of the right arm, and a transient Horner's syndrome were noted. Seven weeks later she presented with severe stridor with impending respiratory failure necessitating emergency intubation; the right-sided Horner's syndrome had recurred. CT imaging showed a large pseudo-aneurysm of the brachiocephalic artery resulting in severe compression of the trachea. Using a prosthetic graft, the operation for the pseudo-aneurysm was successful; there were mild neurological sequelae. Although her family history was negative, autosomal dominant PKD should be considered, and we discuss the possible role of a pre-existing PKD-associated aneurysm.