This article received a double-blind peer review from members of the Cath Lab Digest editorial board.
Disclosure: The authors report no conflicts of interest regarding the content herein.
The authors can be contacted via Muhammad A. Khan, MD, at Muhammad.Khan@SanfordHealth.org.
Over-the-wire (OTW) balloon catheters offer advantages in appropriate scenarios. An OTW system can provide extra support for a coronary guide wire that can be utilized to cross difficult lesions. An OTW system can also be used for distal injection of a coronary artery, to confirm the intra-coronary presence of equipment. This can be very helpful in situations where the distal coronary circulation is not well defined due to complete coronary occlusion. This scenario requires removal of the coronary guide wire from the OTW balloon catheter and the attachment of a contrast-filled syringe for injection. One disadvantage to the use of an OTW system is the need for a longer guide wire for exchanging catheters, which makes the case more cumbersome to perform. If guide wire position is to be maintained while using a short guide wire in an OTW balloon catheter, a guide wire extension can be used to exchange equipment; however, this adds an extra cost.
OTW systems can be retrieved without the use of guide wire extension by utilizing the “hydroglide” technique. The OTW system is pulled back until the guide wire is completely inside the balloon catheter. A small syringe is filled with normal saline and connected to the end of the catheter. Care must be taken to draw back into the syringe in order to avoid air embolism. While injecting through the syringe, the wire maintains an intra-coronary position and the jet of saline leaving the end of the OTW balloon catheter pushes it out in accordance with Newton’s third law of motion. Once the balloon catheter is out of the patient, all tubing is purged and flushed to avoid the risk of embolism. We describe a new technique that further improves the efficiency of the above method.
The above steps are followed until the operator is ready to inject saline through the OTW catheter. At this point, the three-way stopcock connecting contrast tubing to the side port of the hemostasis valve is opened “towards” the patient. This allows blood to flow back in the guiding catheter, to the side tubing, and out. This backwards flow of blood further helps the balloon catheter float out the guiding catheter. The technique reduces the force needed to inject saline through the balloon catheter and only minimal injection pressure is required for safe retrieval of the catheter. We have noted that the higher the patient’s blood pressure, the more support this method provides. One can try “hydrogliding” with the stopcock in the usual position and then, during the syringe injection, turning the stopcock to the position that allows the blood to backflow from the equipment to assist in retrieving the balloon catheter.
In summary, we describe a new technique for removal of an OTW balloon catheter while maintaining coronary guide wire position. This technique can be utilized in situations where other measures for safe catheter exchange fail or are unavailable.