A vessel sealer is a specialized surgical instrument that achieves permanent closure of blood vessels and tissue bundles during medical procedures. This handheld device uses precise mechanical compression and energy to stop bleeding, a process known as hemostasis. It is employed in various surgical settings to manage blood flow and prepare tissues for dissection or removal. This technology creates a reliable seal, which helps maintain a clear surgical field and reduce patient blood loss.
The Sealing Mechanism
Vessel sealers apply high-frequency electrical energy, typically radiofrequency (RF) energy, to tissue captured between the instrument’s jaws. This energy, combined with mechanical compression, generates heat within the vessel walls. The heat denatures collagen and elastin proteins within the vessel. As these proteins cool, they reform and cross-link, fusing the vessel walls to create a permanent, biological seal. This process can seal vessels up to 7 millimeters in diameter.
The device incorporates a feedback loop system that monitors tissue changes during sealing. It measures the tissue’s electrical impedance, indicating its state of desiccation and protein denaturation. Based on these measurements, the system automatically adjusts energy delivery to optimize the seal. This control minimizes thermal spread to surrounding tissues and helps prevent complications like charring or sticking. The system automatically stops energy delivery once the seal is complete, typically within 3 to 5 seconds for a 5 mm vessel.
Common Surgical Applications
Vessel sealers play an important role in both traditional open surgeries and minimally invasive procedures, such as laparoscopic operations. Their ability to provide reliable bleeding control in confined spaces makes them useful in minimally invasive settings where manual suturing is challenging and time-consuming. These devices combine sealing and cutting functions into a single instrument, reducing the need for multiple instrument exchanges. This dual functionality increases surgical efficiency and potentially shortens operating times.
These instruments are used across various surgical specialties, including general, gynecological, and urological surgeries. Specific procedures where vessel sealers are commonly used include hysterectomies (uterus removal), cholecystecties (gallbladder removal), splenectomies (spleen removal), and colon resections. They are also used for tumor resections and adhesiolysis (releasing adhesions). Their precise sealing capabilities help reduce intraoperative blood loss and contribute to a clearer surgical field.
Comparison to Traditional Hemostasis Methods
Before vessel sealers, surgeons primarily relied on methods such as sutures, surgical clips, and standard electrocautery to control bleeding. Sutures involve manually tying off blood vessels with thread. While effective, manual ligation can be time-consuming, especially when many vessels need securing. It also leaves a foreign body, the suture material, within the patient, which can lead to inflammation or adhesions.
Surgical clips, typically made of metal or polymer, are another method used to clamp vessels shut. These clips provide quick occlusion and are easy to apply. However, like sutures, they leave a foreign body in the patient, with a possibility of shifting or dislodging post-surgery. Vessel sealers, by contrast, create a fused, biological seal without leaving foreign material behind, promoting faster wound healing and reducing foreign body complications.
Standard electrocautery, often called monopolar or conventional bipolar coagulation, uses electrical current to burn tissue and coagulate blood. Unlike vessel sealers, which create a strong, fused seal by denaturing collagen and elastin, electrocautery primarily desiccates tissue to stop diffuse bleeding. Vessel sealers offer a more robust and consistent seal, particularly for larger vessels up to 7 mm, and result in less thermal spread to surrounding tissues compared to traditional electrocautery. This precision leads to less tissue trauma and improved patient outcomes.
Types of Energy-Based Sealing Devices
Energy-based vessel sealing devices utilize two forms of energy: advanced bipolar (radiofrequency) and ultrasonic. Advanced bipolar devices, such as the LigaSure system, deliver high-frequency, low-voltage electrical current directly between the instrument’s two jaws. This energy heats the tissue, forming a permanent seal.
Ultrasonic devices, like the Harmonic Scalpel, employ high-frequency mechanical vibrations to generate heat. One jaw vibrates at a very high frequency, typically around 55,000 cycles per second, while the other applies compression. This frictional heating denatures proteins and vaporizes water within the tissue, leading to coagulation and simultaneous cutting. Both advanced bipolar and ultrasonic technologies effectively seal vessels, with some ultrasonic devices capable of sealing vessels up to 7 mm in diameter. Each technology offers unique benefits in terms of lateral thermal spread, sealing speed, and dissection capabilities.