Shortening peel-away sheaths prior to dialysis line insertion—potential decrease of patient risk

Placement of tunnelled dialysis lines is effective using ultrasound and fluoroscopic guidance [1] and has a higher success rate than ‘blind’ insertion [2]. After the ultrasound guided access into a neck vein, wires and catheters are guided in to a suitable position in the venous system. After dilatation, a 16F peel-away sheath is introduced. A dual-lumen dialysis catheter is tunnelled from an appropriate skin entry site and inserted through the peel-away sheath. The sheath is then split and removed by peeling it away. The 16F or similar sized sheath, available from a variety of manufacturers, is 17 cm long and placed together with a rigid dilator of similar size (Figure 1). This means the peel-away sheath assembly is usually inserted well into the heart. When left-sided access is used, there is the potential for wall trauma at the confluence of the left brachiocephalic vein and superior vena cava. In this and other units, we have seen morbidity and mortality due to venous and cardiac perforation during instrumentation. The venous insertion site is usually only 1–3 cm from the skin access site. In principle, the peel-away sheath system need not be any longer than this, as venous access is maintained after removal of the wire and dilator. This point was made by Nixon in a letter to the Br Med J [3]. We have started to cut the peel-away sheath to half its length (8 cm) (Figure 2) Once the dilator part of the assembly is a few centimetres in (Figure 3), the shortened peel-away sheath can be advanced over the dilator into the vein while holding the dilator steady (Figure 4). The dilator is removed and the dialysis line inserted as normal. There is therefore no intra-cardiac insertion of the stiff peelaway sheath/dilator assembly, minimizing the risk of cardiac trauma.