Cardima NAVIPORT® Deflectable Guide Sheath for Ablation of Cardiac Arrhythmias

Byron K. Lee, MD
Byron K. Lee, MD
Sheaths are very useful in the ablation of cardiac arrhythmias. However, choosing the right sheath with the correct shape for a particular ablation procedure can sometimes be challenging. Often, multiple sheaths have to be pulled off the shelves before the ablation is successful. Recently, Cardima (Fremont, California) has developed the 11 French (Fr) NAVIPORT ® deflectable guide sheath (Figure 1) which can be used in conjunction with standard ablation catheters. The deflectable tip allows the sheath to take on many possible shapes. The ablation catheter sits inside the sheath. The ablation catheter can slide back and forth in the sheath and the deflectable tip of the ablation catheter can be used together with the deflectable tip of the guide sheath. With this sheath, the electrophysiologist has additional freedom of motion and can stably place the ablation catheter tip at many more areas of targeted cardiac tissue. Therefore, the usage of multiple standard sheaths with fixed conformation can often be avoided. We present a redo atrial flutter case in which the deflectable sheath was very useful in facilitating the ablation. The patient was a 55-year-old man who presented with recurrent palpitations. He had a history of atrial fibrillation and atrial flutter. Atrial flutter ablation was originally attempted seven months previously. During that procedure, the patient was diagnosed with typical counterclockwise atrial flutter. A St. Jude/Diag 8 Fr atrial flutter ablation sheath (SAFL) and an EPT Blazer II ablation catheter was used in the first case for ablation. Although the atrial flutter terminated during ablation, bidirectional block could not be clearly demonstrated at the end of the procedure. Subsequently, the patient presented again with palpitations, which were eventually diagnosed as recurrent atrial flutter. When the patient was brought to the electrophysiology laboratory for the second time, he was still in atrial flutter. Quadripolar catheters were placed in the high right atrial position and the His position. A duodecapolar catheter was looped along the lateral wall of the right atrium and across the isthmus. A Boston Scientific/Cardiac Pathways (Natick, Massachusetts) Chilli ablation catheter was inserted through the NAVIPORT ® deflectable guide sheath and placed at the isthmus (Figure 2). The intracardiac electrograms indicated that the patient had recurrence of his typical counterclockwise atrial flutter. Overdrive pacing at the isthmus showed concealed entrainment, which proved that the isthmus was in the circuit (Figure 3). Ablation was performed at the isthmus using the NAVIPORT ® deflectable sheath to direct the tip. The NAVIPORT ® allowed us to direct the tip precisely and to get excellent contact. Atrial flutter terminated during ablation. Pacing medial and lateral to the ablation line clearly showed bidirectional block. The ablation portion of the procedure, which excludes the diagnostic parts of the study, took only 15 minutes. At 3 months follow-up, the patient is doing well and still free of atrial flutter. As demonstrated in the case above, the NAVIPORT ® deflectable guide sheath can be very useful for the ablation of arrhythmias, particularly in redo cases. We recognize that for our patient, the success of the second ablation procedure may very well have been due to the use of the Boston Scientific/Cardiac Pathways Chilli ablation catheter, which can achieve deeper burns. However, we felt strongly that the NAVIPORT ® also was helpful in the redo procedure. The NAVIPORT ® gave us better maneuverability. We could deflect the sheath at just the right angle to create the ablation line at the desired region of the isthmus. Furthermore, we were able to use the deflectability of the guiding sheath to push us stably down onto the target tissue. No additional sheaths had to be used to achieve success. The ablation portion of the study was done unexpectedly swiftly. Cardima makes several NAVIPORT ® deflectable guide sheaths. The newest design with the largest diameter is the sheath most suitable for radiofrequency ablation. The outer diameter is 11 French and the inner diameter is 8.2 French. It has a working length of 73 centimeters (94 centimeters including the direction handle) and a curve reach of 4 centimeters. The shaft is radiopaque and the tip is soft to prevent trauma. It can be used with a variety of standard ablation catheters, including the ones listed below (Figure 4). NAVIPORT ® deflectable guide sheaths can also be used for the delivery of diagnostic catheters or for obtaining access into the coronary sinus. Use of the NAVIPORT ® deflectable guide sheath can potentially save time and lower cost by replacing the use of multiple fixed curve sheaths. The NAVIPORT ® deflectable guide sheath is useful for ablation of arrhythmias. It can be used with several standard ablation catheters. By replacing the usage of multiple fixed curve sheaths, it can potentially save time and lower cost.