Thermal Spread of LigaSure Impact Handheld Device
The LigaSure device produces lateral thermal spread of approximately 4.5-5.9 mm in tissue, with significantly higher thermal damage compared to ultrasonic devices but lower than monopolar electrocoagulation.
Quantified Thermal Spread Measurements
Based on direct comparative research, the LigaSure device demonstrates the following thermal characteristics:
Lateral Thermal Damage
- Mean full-thickness thermal spread: 4.5 mm 1
- Superficial lateral thermal spread: 5.9 mm 1
- Mean blade temperature: 103.14°F (39.5°C) - second lowest among energy devices tested 1
Comparative Context
When compared to other surgical energy devices 1:
- Harmonic ACE: 2.4 mm full-thickness spread (significantly less thermal damage)
- Harmonic LCS-C5: 3.1 mm full-thickness spread (less thermal damage)
- Monopolar diathermy: Substantially greater thermal spread, reaching 59.2°C at 1 cm distance 2
Clinical Implications
LigaSure produces significantly more thermal injury than ultrasonic devices 3. A recent study specifically found "significantly higher thermal damage was found on the mesoappendix and appendiceal base in patients treated with LigaSure than in patients for whom Harmonic Scalpel was used" 3.
Tissue-Specific Findings
In veterinary palatoplasty studies, LigaSure demonstrated:
- Mean thermal injury depth: 874.94 ± 184.92 μm 4
- Tissue damage grade: 3.7 ± 0.48 (on a 1-4 scale) 4
- Significantly higher than CO2 laser (451.76 μm depth, grade 2.8) 4
Temperature Profiles
In thyroid tissue studies, LigaSure showed 5:
- Maximum temperature: 96.5 ± 5.6°C
- Time above 60°C: 5.3 ± 0.97 seconds
- No significant difference in lateral spread at 39°C, 40°C, or 60°C thresholds compared to ultrasonic devices
Important Caveats
Thermal spread is NOT directly correlated with blade temperature alone 1. Multiple factors influence tissue damage:
- Transection time
- Tissue properties and vascularity
- Power settings used
- Duration of application
The device remains above 42°C for approximately 15 seconds after a 5-second application 2, which can contribute to ongoing thermal injury if not properly managed.
Clinical Recommendations from Guidelines
The 2020 WSES Jerusalem Guidelines state that monopolar electrocoagulation and bipolar energy are the most cost-effective techniques for mesoappendix dissection, while LigaSure represents a high-cost option that may be advantageous specifically in inflamed, edematous, or gangrenous tissue 3.
There are no clinical differences in outcomes, length of hospital stay, and complication rates between different energy devices when used appropriately 3, suggesting that thermal spread measurements, while important for understanding device characteristics, do not necessarily translate to different clinical outcomes in routine use.