Acessa
®
ProVu System User’s Guide
PL-01-0040
CO 20-131 Revision: C
20
11.
Special Considerations: General Ablation Procedures
11.1.
Highly Vascularized Tissue
If all connections are verified to be correct and desired temperatures continue to not be obtainable, the electrode
arrays may have been deployed into a highly vascular area. Consider withdrawing the electrode arrays (if deployed)
into the Handpiece and then rotating or repositioning the Handpiece.
11.2.
One or More Electrode Arrays in a Duct or Vessel
If one or more Electrode temperatures reads much lower than the rest of the temperatures, the electrode array may
be in or near a vessel or duct. To correct this condition, stop the delivery of RF energy by depressing the foot pedal.
Fully retract the electrode arrays (if deployed), then rotate the Handpiece. Redeploy the electrode arrays, and restart
the ablation by depressing the foot pedal again.
11.3.
Ablation of Dense or Calcified Fibroid Tissue
Incremental advancement of the electrode arrays will aide in penetrating dense tissue. With Console set for
temperature control and the Handpiece tip placed at the required depth for ablation, activate RF until target
temperature is reached. Deploy the electrode arrays ½ cm and maintain this deployment until target temperature is
reached. Continue with ½ cm to 1 cm deployment increments, reaching target temperature, until the last deployment
is achieved (e.g., 5 cm deployment in muscle for 12 minutes creating a final ablation size of 5.6 cm by 4.4 cm). Maintain
target temperature for stated target time for the last deployment stage to allow for complete tissue destruction.
If a fibroid is densely concentrated with calcium to the degree that there is abnormal resistance to insertion and/or
rotation of the Acessa Handpiece tip (with electrode arrays fully retracted):
o
discontinue rotating the device
o
withdraw the Handpiece by pulling back along the path of insertion (electrode arrays retracted, do not rotate)
o
re-enter the fibroid from another direction (ideally where the sonographic appearance demonstrates
fewer/smaller calcium deposits).
Once the tip of the Handpiece is positioned in a desired location, if deployment of the electrode arrays is impeded by
calcium deposits:
o
Fully retract the electrode arrays and carefully rotate the device 3-5 degrees, then re-attempt deployment (repeat
the retraction/slight rotation/deployment method if necessary until deployment is achieved).
o
deployment cannot be achieved in spite of repeated efforts, fully retract the electrode arrays and attempt
deployment with the Acessa Handpiece tip repositioned in another location within the fibroid.
12.
Ex-Vivo Studies
12.1.
Ex-Vivo Studies
Bench top studies were conducted using Bovine liver. The purpose of these studies was to characterize the ablation
size when created with different deployments for varying amounts of time and at different power and temperature
settings. Generally, for a given time, increasing the target power or temperature tends to produce larger ablation
sizes. For a given target power or temperature, increasing the time tends to produce larger ablation sizes.
12.2.
Representative Ablation Shape per Deployment
*Major dimension = length or axial length
*Minor dimension = width
