Surgeons close off blood vessels using a range of instruments, from simple hand-held clamps to advanced energy devices that seal tissue with heat or ultrasonic vibration. The right tool depends on the vessel’s size, whether the closure needs to be temporary or permanent, and whether the surgery is open or minimally invasive.
Hemostatic Forceps
Hemostatic forceps are the most fundamental instruments for clamping blood vessels during surgery. They work by physically crushing the vessel walls together to stop blood flow, and they come in several sizes matched to different vessel diameters.
The smallest and most precise is the Halstead mosquito forceps, used for pinpoint control of small bleeding vessels. Its delicate jaws make it ideal for superficial tissue or areas where precision matters. For larger vessels, surgeons step up to Kelly forceps or Crile forceps. These two look similar but differ in one key way: Kelly forceps have grooved serrations only on the tips of the jaws, while Crile forceps have serrations running the entire jaw length. That full-length grip gives the Crile a stronger hold on bulkier tissue.
For the largest jobs, Rochester-Carmalt forceps are heavy crushing instruments with long, wide jaws featuring longitudinal grooves and fine cross-hatching at the tip. These are typically used to clamp thick tissue bundles (called pedicles) before they’re tied off with suture.
Vascular Clamps for Temporary Occlusion
When a surgeon needs to stop blood flow through a vessel temporarily, without damaging the vessel wall, they use atraumatic vascular clamps. These are designed with smooth or lightly serrated jaws that hold the vessel closed gently enough to preserve the inner lining for later repair.
Bulldog clamps are small spring-loaded devices that snap onto a vessel to block flow during the procedure. They’re commonly used on smaller arteries and veins where quick, temporary occlusion is needed. Satinsky clamps serve a different purpose: they’re shaped to clamp only part of a large vessel’s wall, allowing the surgeon to work on one section of the aorta or another major vessel while blood continues flowing through the rest. This partial, or tangential, occlusion is a core technique in cardiovascular surgery.
Microvascular Clamps
Microsurgery on tiny vessels (often less than a few millimeters in diameter) requires instruments scaled down to match. Microvascular clamps are typically single-piece stainless steel devices with a V-shaped spring design that relies on the metal’s own elasticity to hold the vessel closed. They come in sizes ranging from extra-extra-small to extra-large, with the smallest used in highly specialized procedures like lymphatic-to-vein connections and tissue flap surgery.
Beyond simple single clamps, surgeons use double clamps (two clamps mounted on one frame to isolate a segment of vessel) and gamma clamps, which add a third clamp on a perpendicular rail. The gamma design is particularly useful for end-to-side vessel connections, where one vessel is being sewn into the side of another. The rail system holds both vessels in position without needing an extra pair of hands.
Ligating Clips
When a vessel needs to be permanently sealed, especially in minimally invasive surgery, surgeons often apply small clips rather than tying sutures by hand. A clip applier places a metal or plastic clip across the vessel, crimping it shut.
The two main clip materials are titanium and absorbable polymer. Titanium clips are strong and widely used, but they’re permanent metal implants that can interfere with CT scans and, in rare cases, erode into surrounding tissue. Absorbable polymer clips dissolve over weeks and actually grip harder initially. Testing on excised tissue showed that the force required to dislodge an absorbable clip was significantly greater than for titanium clips in both directions of pull. The trade-off is that absorbable clips lose strength over time, retaining only about 11% of their original holding power by day 21. By that point, the body’s own healing has typically sealed the vessel permanently.
Energy-Based Vessel Sealers
Modern surgery increasingly relies on devices that use electrical current or ultrasonic vibration to fuse vessel walls shut. These tools seal and cut in a single step, which speeds up procedures and reduces the number of clips or ties left in the body.
Bipolar electrosurgical sealers pass controlled electrical current through the vessel tissue clamped between two jaws. The heat denatures proteins in the vessel wall, creating a permanent seal. Devices in this category (such as the LigaSure and EnSeal systems) consistently produce the highest burst pressures in testing, meaning the sealed vessel can withstand significant internal pressure before failing. A successful arterial seal needs to hold at least 300 mmHg, more than double normal blood pressure, and top-performing bipolar sealers regularly exceed this threshold.
Ultrasonic sealers (such as the Harmonic Scalpel) vibrate at extremely high frequency, generating frictional heat that coagulates and cuts tissue simultaneously. They produce less lateral heat spread than electrosurgical devices, which can matter near delicate structures. In comparative testing on arteries of various sizes, ultrasonic devices performed well on small and medium vessels (2 to 5 mm) but showed a slightly higher failure rate on medium-diameter arteries compared to the best bipolar sealers.
Both types of energy devices are effective on vessels up to about 7 mm in diameter. For vessels larger than that, surgeons generally rely on sutures or stapling devices.
Suture Ligation
The oldest and still widely used method of closing a blood vessel is tying it off with suture thread. A surgeon clamps the vessel, wraps suture around it, and ties a secure knot. For larger or higher-pressure arteries, a transfixion ligature adds security: the needle passes through the vessel wall before tying, which prevents the suture from slipping off the stump.
Suture material choice matters for long-term outcomes. Absorbable sutures (like polyglactin, sold as Vicryl) and non-absorbable sutures (like silk) both seal arteries effectively. However, studies comparing the two on ligated arteries found that silk caused noticeably more inflammation and granuloma formation at eight weeks than absorbable suture did. Both materials triggered some thickening of the vessel’s inner lining, but the reduced tissue reaction with absorbable suture makes it the preferred choice in many settings.
How Surgeons Choose the Right Instrument
The decision comes down to a few practical factors. Vessel size is the most important: mosquito forceps and small clips work for tiny bleeders, while energy sealers and suture ligation handle medium to large arteries. Whether the closure is temporary or permanent matters too. Bulldog and Satinsky clamps are designed to come off, leaving the vessel intact, while clips, sutures, and energy seals are meant to be final.
The surgical approach also plays a role. In open surgery, a surgeon can tie sutures by hand with relative ease. In laparoscopic or robotic procedures, where instruments pass through small ports, clip appliers and energy sealers are far more practical because they can be operated with one hand through a narrow space. Cost, availability, and the specific anatomy of the surgical site all factor in as well. In practice, most procedures use several of these tools in combination, matching each instrument to the vessel and moment it’s best suited for.