Written and maintained by CASRAI Editorial Board
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General product and regulatory information for laboratory and clinic staff, drawn from the FDA, the manufacturer’s labeling and published papers. It is not medical advice and does not describe how to perform any procedure.
Short answer
LigaSure is Medtronic’s (formerly Covidien’s) brand of bipolar vessel-sealing instruments. An instrument grips tissue, a compatible generator delivers controlled bipolar energy, and the vessel wall is fused rather than tied or clipped. The FDA file for one LigaSure instrument describes it as a sterile, single-use, hand-held bipolar electrosurgical instrument that seals and divides vessels up to 7 mm in diameter.
Definition and scope
“Vessel sealing” is the general term for using pressure plus bipolar radiofrequency energy to fuse the walls of a blood vessel or tissue bundle. LigaSure is one brand of vessel sealing device. In the FDA’s classification, such instruments fall under the regulation for electrosurgical cutting and coagulation devices and accessories (21 CFR 878.4400), class II, product code GEI. The regulation identifies the device type as one “intended to remove tissue and control bleeding by use of high-frequency electrical current” (eCFR, checked 2026-10-31).
The instrument is only one half of the system. The 510(k) summary for the LigaSure Curved, Small Jaw, Open Sealer/Divider (K113572, dated 8/29/2012) says the instrument is designed exclusively for use with the manufacturer’s ForceTriad energy platform (the generator). A cord with a “smart” connector carries a unique product identifier so the generator recognises the instrument. For the wider device family, see our guide to the electrosurgical unit.
How vessel sealing works in practice
Two published descriptions cover the mechanism, with different emphasis.
- The FDA summary for K113572 says the tissue-fusion mode “delivers precise energy to tissue for a controlled time period to achieve complete and permanent tissue fusion”, designed to produce minimal sticking, charring or thermal spread to adjacent tissue. The electrodes sit on the inner jaw surfaces; energy is activated from a handle button or a generator footswitch; and a trigger-controlled stainless steel blade mechanically divides the tissue after fusion.
- A surgeon’s review of the 5 mm blunt-tip laparoscopic instrument (Karande, J Obstet Gynaecol India 2015;65(5):350-352) describes LigaSure as using “a combination of pressure and continuous bipolar energy to create vessel fusion”, with the generator monitoring tissue and adjusting energy. It reports sealing of vessels as large as 7 mm and a “95 % probability of a burst pressure greater than three times normal systolic blood pressure” (the article states LigaSure “has a 95 % probability” of this). This is one author’s narrative summary, not a head-to-head trial.
What is the thermal spread of LigaSure?
Thermal spread is the heating of tissue beyond the jaws. There is no single universal figure for LigaSure; it is stated per device, by the manufacturer. Medtronic’s best-practices sheet for the LigaSure Maryland Jaw thoracic device (LF1930T, 08/2024) states “Average thermal spread is < 2 mm”, citing a Medtronic internal report from December 2017. That is a manufacturer claim for that device, not an independent measurement and not a figure for other LigaSure models.
The FDA file reads differently: for K113572, bench testing showed higher mean burst pressure and lower mean temperatures than the predicate devices, and animal testing showed mean thermal spread “comparable to the predicates for all vessel sizes evaluated”. The 510(k) summary therefore supports a claim of comparability to earlier cleared devices, not a stated millimetre figure.
What does the labeling and FDA file actually say?
| Item | What the source states | Source |
|---|---|---|
| Regulatory class | Class II, 21 CFR 878.4400, product code GEI; common name “bipolar electrosurgical instrument” | FDA 510(k) summary K113572; eCFR |
| Supply form | Sterile, single-use, hand-held | K113572 |
| Generator | Designed exclusively for use with the ForceTriad energy platform; smart connector with a unique product identifier | K113572 |
| Vessel size | Vessels up to 7 mm in diameter, tissue bundles and lymphatics (open general surgery) | K113572 |
| Open ENT use | Labeled for adults in open ENT surgery | K113572 |
| Exclusion | Not shown to be effective for tubal sterilization or tubal coagulation; not for these uses | K113572 |
| Thoracic device | Pulmonary arteries and veins up to and including 7 mm; safety and efficacy not established for lung parenchyma | Medtronic LF1930T sheet, 08/2024 |
What are the different types of LigaSure devices?
The FDA file, Medtronic labeling and a published review document three distinct device types. This is not a catalogue of the full product line.
- Open small-jaw sealer/divider (LF1212, K113572): a curved, small-jaw open instrument for open general surgery and, in adults, open ENT.
- Maryland-jaw thoracic device (LF1930T): labeled for pulmonary arteries and veins up to and including 7 mm, and for tissue bundles and lymphatics up to 7 mm.
- 5 mm blunt-tip laparoscopic instrument: described in the Karande review as the laparoscopic member of the family; see our guide to laparoscopic instruments for how energy devices sit among other instruments.
What is the difference between LigaSure and Harmonic scalpel?
They are different energy technologies. LigaSure is bipolar radiofrequency with pressure; Harmonic is ultrasonic. Per the Karande review, Harmonic uses a “high-frequency ultrasonic transducer (55,000 cycles/s) to create mechanical vibration of one of the two jaws”. The author states that Harmonic has “the least thermal spread and smoke production of all the devices” and LigaSure the highest burst pressure, and notes that older Harmonic versions had “poor reliability” sealing vessels while the Harmonic Ace+7 can coagulate vessels up to 7 mm in diameter. These are one author’s conclusions from a narrative review, so treat them as a summary of the literature at that date rather than a current head-to-head result.
| Feature | LigaSure (vessel sealing) | Harmonic (ultrasonic) |
|---|---|---|
| Energy | Pressure plus continuous bipolar energy | Ultrasonic vibration of one jaw (55,000 cycles/s) |
| Vessel size cited | Up to 7 mm | Harmonic Ace+7 can coagulate vessels up to 7 mm |
| Strength cited by author | Highest burst pressure | Least thermal spread and smoke |
Both columns summarise Karande 2015 (PMC4579154).
Where it matters for labs, clinics and supply decisions
A checklist built only from what the sources state:
- Generator compatibility. The K113572 instrument is designed exclusively for the ForceTriad platform, so the instrument and generator are a matched pair.
- Single-use status. The cleared instrument is labeled sterile and single-use.
- Indication per device. Open, laparoscopic and thoracic instruments carry different labeled indications; the thoracic sheet excludes lung parenchyma and the open small-jaw summary excludes tubal sterilization.
- Which thermal figure. A “< 2 mm” claim belongs to LF1930T only; the 510(k) summary uses comparability to predicates.
- Not a clip or tie. Sealing devices and ligating clips are different hemostasis tools; see hemostasis clips.
Common misunderstandings
- “LigaSure” is not a generic term. It is one brand; “vessel sealing” is the category.
- A thermal spread number is not universal. It is device-specific and, in the cited case, a manufacturer figure.
- Cleared does not mean interchangeable. A 510(k) clears a specific device for specific indications.
FAQ
What is the thermal spread of LigaSure?
For the LF1930T thoracic device, Medtronic states average thermal spread under 2 mm. Other devices have their own labeling; the FDA file for K113572 calls animal thermal spread comparable to its predicates.
What are the different types of LigaSure devices?
The FDA file, Medtronic labeling and a published review document an open small-jaw sealer/divider, a Maryland-jaw thoracic device and a 5 mm blunt-tip laparoscopic instrument. Each has its own labeled indications.
What is the difference between LigaSure and Harmonic scalpel?
LigaSure fuses vessels with pressure and bipolar energy; Harmonic uses ultrasonic vibration. One surgeon’s 2015 review credits LigaSure with the highest burst pressure and Harmonic with the least thermal spread and smoke.
What does vessel sealing mean?
It is the fusion of vessel walls with pressure and bipolar energy, rather than closing them with a tie or clip. In the US such instruments are class II under 21 CFR 878.4400.
Sources
- FDA 510(k) summary K113572, Covidien LigaSure Curved, Small Jaw, Open Sealer/Divider LF1212, 8/29/2012: accessdata.fda.gov (checked 2026-10-31).
- 21 CFR 878.4400, Electrosurgical cutting and coagulation device and accessories: eCFR (checked 2026-10-31).
- Medtronic, Optimizing pulmonary vessel sealing with the LigaSure Maryland Jaw thoracic device (LF1930T), 08/2024: Medtronic PDF (checked 2026-10-31).
- Karande VC, LigaSure 5-mm Blunt Tip Laparoscopic Instrument, J Obstet Gynaecol India 2015;65(5):350-352: PMC4579154 (checked 2026-10-31).
