Over-the-wire (OTW) balloons are frequently used for coronary interventions with a guide wire as they provide extra support while crossing a tight lesion and the capability of providing a confirmatory picture of the distal vessel. They also allow for guide wire exchanges. Using a long wire with an OTW balloon is often cumbersome. A short wire on the other hand, needs an extension to exchange the OTW balloon for another device (i.e., stent), which in turn adds cost and complexity to the procedure.
We have previously described the “hydroglide” technique “booster” that enables us to more safely use a short guide wire in an OTW balloon and glide the balloon out while retaining the guide wire in its coronary position.1 The OTW balloon is completely pulled within the guide catheter while retaining the guide wire tip in its distal coronary position. A 5 cc saline-filled syringe that is free of air is then connected to the balloon catheter and the saline is injected, resulting in the balloon catheter gliding out over the guide wire while the guide wire’s tip is retained in its original position. This technique is diagrammatically represented in Figure 1. The technique can be boosted by opening the side port of the guide catheter so as to allow for blood return through this while “hydrogliding” the balloon catheter out.
While this technique works well, there is a potential difficulty in “hydrogliding” if there is any problem with the inner lumen of the OTW hypotube such as luminal irregularity, tortuosity, or cholesterol debris that could potentially increase its resistance. Then, a higher “hydrogliding” pressure would be required, that may not be obtainable manually with a 5 cc saline-filled syringe. We have encountered such a situation, where in spite of applying maximal manual pressure to the 5 cc saline-filled syringe (resulting in bending and breaking of its plunger), the balloon catheter stopped halfway into the gliding out process and pulling the pressurized system back would pull the guide wire back, too. Thus, we decided to use an indeflator for applying controlled and higher pressure. The indeflator was attached to the end port of the OTW balloon and a pressure of about 14 atmospheres was generated by continuous turns on its handle, resulting in the OTW catheter gliding out with ease. This “power glide” technique uses the same principle as the initial “hydroglide” technique, but the indeflator is used to generate a high and controlled pressure that is not possible to generate manually with the 5 cc syringe. The system is shown assembled outside the body in Figures 2-4.
We subsequently bench tested the pressure generated by the 5 cc syringe by connecting it to the indeflator and it registered at about 6-8 atmospheres, causing already, at this point, some injury to the operator’s hand at less than half of the pressure that would be needed to glide the OTW balloon catheter out in this situation. A 10 cc and 20 cc syringe could generate, using similar forces, only 5 atm and 4 atm of pressure, respectively (Figure 5). Using an indeflator instead of a syringe with the “hydroglide” system enables us to generate higher and better controlled pressure that is not otherwise possible.
- Stys AT, Khan MA, Rajpurohit N, Stys TP, Petrasko M. Guidewire hydroglide technique “booster”. Cath Lab Digest. 2014 July; 22(7). Available online at http://www.cathlabdigest.com/articles/Guidewire-Hydroglide-Technique-%E2%80%98Booster%E2%80%99. Accessed March 21, 2015.
The authors can be contacted via Dr. Adam Stys at email@example.com.