Surgical clips are small, specialized medical devices used by surgeons to mechanically secure tissues or close off tubular structures, such as blood vessels and ducts, during an operation. They serve as an alternative to traditional suture tying, offering a faster and often more precise method of sealing anatomy. Designed for rapid application with specialized instruments, clips provide immediate and secure compression, achieving hemostasis or ligation.
Physical Appearance and Composition
Surgical clips are tiny, precisely formed objects that vary significantly in size, typically ranging from a few millimeters to a little over a centimeter in length when closed. Their visual appearance depends on the material. Metallic clips have a shiny silver or gray sheen, while polymer clips are often colored (e.g., green or purple) to aid visibility and match their applicator size. Metal clips are commonly made of biocompatible materials like titanium or stainless steel, preferred for their inert nature and strength.
The shape of the clips is designed for function. Many small hemostatic clips resemble a V-shape before application and are crimped closed to securely compress the target structure. Larger clips, often polymer or polymer-metal combinations, may feature a hinged design with an internal locking mechanism for a secure, non-slip closure on wider ducts or vessels. The surface of some clips is etched with microscopic serrations or striations, which help grip the tissue and prevent slipping after application.
Primary Functional Categories
Clips are categorized primarily by the function they perform. Hemostatic clips are frequently used to control bleeding by clamping and occluding blood vessels. They provide immediate mechanical pressure, which is a fast method of sealing arteries or veins, particularly when numerous small bleeders must be secured quickly.
Another major category is ligation clips, which are used to permanently close off ducts or tubes rather than blood vessels, such as the cystic duct during a gallbladder removal or the fallopian tubes in a sterilization procedure. These clips often utilize a locking mechanism, especially in polymer variants, to ensure the closure remains secure over time. Specialized clips, such as aneurysm clips used in neurosurgery, are placed on the neck of an aneurysm to exclude it from circulation and prevent rupture.
Clips in the Body: Permanence and Imaging
When surgical clips are placed, their fate depends entirely on the material composition, as they are either permanent or absorbable. Most metal clips, particularly those made from titanium, are designed to remain in the body indefinitely and are considered inert, meaning they do not react with surrounding tissue. Absorbable clips, made from polymers like polyglycolic acid, maintain their strength temporarily before gradually dissolving, typically disappearing within six months after placement.
The long-term presence of metal clips makes them visible on medical imaging, appearing as bright white, dense objects on X-rays and Computed Tomography (CT) scans. While useful for post-operative follow-up, they can sometimes create artifacts or streaks on CT images. A significant concern is Magnetic Resonance Imaging (MRI); however, most modern surgical clips, especially those made from titanium, are considered MRI-safe because they are non-ferromagnetic. They will not move or heat up dangerously in the strong magnetic field. Patients with any implanted device are always screened carefully before undergoing an MRI, as older or specialized clips, such as some aneurysm clips, may still carry a risk.