The formation of guidewire knots during PICC insertion is an extreme rare complication. Forced insertion or withdrawal of a knotted guidewire may cause tearing of the veins. Surgical guidewire removal is required due to risk of vascular injury.
Saito H, Suda T, Nishida Y. Guidewire knot formation with peripherally inserted central catheter. Clin Case Rep. 2020 Dec 15;9(2):1035-1036. doi: 10.1002/ccr3.3662. PMID: 33598295; PMCID: PMC7869393.