Forum topic

I seem to have the same problem as you Heather; know there's references out there but could only locate this one, which refers to ports:

...Vascular injury with subsequent thrombosis has been reported to occur more frequently in patients who have a left-sided catheter (34,35). When inserted from a left-sided approach, the catheter tip will turn from the left brachiocephalic vein into the SVC and will lie against the right lateral wall of the SVC. The catheter must be of sufficient length to completely turn this corner to position the catheter tip into the lower segment of the SVC. However, if the catheter is too short, the catheter tip will poke into the right lateral wall of the SVC. Continual movement of the catheter tip caused by cardiac pulsations or patient movement may incite progressive damage to the vascular wall and increase the likelihood of thrombosis. Puel and colleagues (34) evaluated the association between catheter tip position and subsequent thrombosis in 379 patients who received a port for chemotherapy. Ten patients (2.6%) had symptomatic venous thrombosis documented by contrast material–enhanced venography, nine of whom had thrombosis of the SVC and one of whom had thrombosis of the left subclavian vein. An analysis of the data revealed that there was a 28.6% incidence of thrombosis if the catheter was inserted from the left side and the tip was positioned in the upper half of the SVC. There was a 3% incidence of thrombosis when the catheter was inserted from the right side and the tip was positioned in the upper SVC. However, if the catheter tip was positioned in the lower SVC or upper right atrium, the incidence of thrombosis was 1.5% when the catheter was inserted from the right side. There were no episodes of thrombosis if the catheter was placed from the left side and the tip was positioned in the lower SVC or upper right atrium (34).

Vesely, Thomas M. MD Central Venous Catheter Tip Position: A Continuing Controversy. Journal of Vascular & Interventional Radiology. 14(5):527-534, May 2003