Inherent Tissue Selectivity; Increasing Tissue Selectivity - Integra Cusa Excel Service Manual

CUSA EXcel Ultrasonic Surgical Aspirator System Service Manual

Inherent Tissue Selectivity

With all other variables remaining constant, the tip does not fragment all tissue
types equally effectively. Another variable—tissue strength—affects
fragmentation rate.
• "Low strength" tissues (easiest to fragment) include the brain and most
organs. Older, partially dried tissues are also easy to fragment. "High
strength" tissues (most difficult to fragment) include vessel structures,
tendons, ligaments, healthy skin, and organ capsules.
• Strength increases and fragmentation rate decreases with tissue containing
greater collagen, elastin, or both (collagen type, quantity, and organization
affect cell structural quality).
Tissue strength also affects tactile feedback. The surgeon can feel a difference
between the tip contacting low-strength tissue and the tip contacting high strength
tissue. As the tip works through low strength tissue, the surgeon feels a smooth,
rhythmic sensation from the handpiece. When the tip contacts high strength
tissue, it feels like it is "bouncing off" the tissue. Also, the smooth, rhythmic
sensation becomes rougher. To avoid fragmenting high strength tissue, the
surgeon must apply less pressure to the tip or move the tip away from the tissue.
To continue fragmenting high strength tissue, the surgeon must manually apply
more pressure.
However, the surgeon may not always recognize the difference in tactile feedback
quickly enough, or react quickly enough, to avoid damaging vital structures,
particularly those with a tissue strength similar to the tissue being fragmented.
The CUSA EXcel system can help the surgeon when dissecting near vital
structures.

Increasing Tissue Selectivity

It is possible to increase the inherent selectivity resulting from variations in tissue
strength while maintaining stroke amplitude, tip acceleration, and suction. This
increase in selectivity results from reducing the reserve power that drives the tip.
How the TissueSelect Feature Works
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