Implantation tools and techniques
While many of the fundamental aspects of device implantation are no different when utilizing a lumenless lead, the process of placing the lead in the desired location within the heart is fundamentally different. When using a standard stylet-driven lead the stylet can be withdrawn and shaped to allow the implanter to direct the lead. The stylet is a stainless-steel wire (26-29 gauge) designed to direct the lead tip by torquing the stylet wire within the lead inner lumen with the stylet knob at the proximal end. The shape applied to the stylet is critical to achieve the desired location. When implanting a lumenless lead the implanter utilizes either pre-shaped or deflectable delivery catheters to direct the lead. The intent of utilizing catheter delivery is to provide increased control over positioning the lead tip in the desired anatomical location. [10]. For right ventricular lead placement, we target placement on the interventricular septum and mainly utilize either a curved catheter with a short 90-degree secondary curve (C315 His), a straight deflectable catheter with a short 90-degree secondary curve (C304-HIS), or for large ventricles a straight deflectable (C304-L69 and C304-S59) catheter. For atrial lead placement we utilize either a J-shape catheter (C315J) or the straight deflectable catheters mentioned above which can allow for placement on the interatrial septum. These designs are intended to create the flexibility for lead placement anywhere in the right atrium or ventricle. The non-deflectable sheaths have an outer diameter allowing for introduction through a 7F outer sheath while deflectable sheaths have an 8.4F outer diameter and must be placed through a 9 F outer sheath. While the delivery catheters can be placed directly into the vasculature, the potential advantage of using an outer sheath is that it avoids the need to regain vascular access should a lead become dislodged during or after removal of the delivery catheter. While we recommend the routine use of separate venipunctures, if an outer sheath is used, a second guidewire can be placed into the outer sheath alongside the lead allowing for retention of vascular access. For these reasons, we suggest the use of an outer sheath when beginning to use the 3830 lead.