A surgical clip is a small metal or polymer device used during surgery to clamp shut blood vessels, ducts, or other tubular structures. Think of it as a tiny, permanent (or sometimes temporary) clamp that pinches tissue closed to stop bleeding or prevent leakage. Surgical clips are one of the most common tools in modern surgery, used in everything from gallbladder removal to brain aneurysm repair.
How Surgical Clips Work
The basic mechanism is straightforward: two small arms or prongs come together to compress tissue, squeezing a vessel or duct shut. This mechanical pressure stops blood flow through a vessel or prevents fluids like bile from leaking out of a cut duct. Once applied, the clip holds the tissue edges tightly together. Over time, the body forms a thin layer of new tissue across the clamped area, essentially sealing it permanently and reconstructing the vessel wall.
Clips range in size from a few millimeters to roughly 17 millimeters, depending on the structure they need to close. Surgeons choose the size based on the diameter of the vessel or duct and how much compression force is needed to keep it sealed.
Materials: Titanium vs. Absorbable Polymer
Most surgical clips fall into two categories: metal or absorbable polymer.
Titanium clips are the traditional choice. They’re strong, lightweight, and stay in your body permanently. Once placed, the surrounding tissue gradually encapsulates them in a thin layer of scar tissue, and they typically cause no issues for the rest of your life. Titanium is also largely compatible with MRI machines, though your doctor will want to know about any clips before ordering a scan.
Absorbable polymer clips are made from materials like polyglycolic acid or polydioxanone. These dissolve in the body over time through a natural process called hydrolysis, where water gradually breaks the material down. The breakdown products are either processed through your body’s normal metabolic pathways or excreted in urine. Polydioxanone clips, for example, take roughly 180 to 238 days to fully dissolve.
Research comparing the two types has found that absorbable clips actually grip harder than titanium ones. In testing on excised tissue, the force required to dislodge an absorbable clip was significantly greater than for a metal clip, in both pulling directions. That grip strength does decrease over time as the material dissolves, dropping to about 11% of its original strength by day 21. But by that point, the body’s own healing has typically sealed the tissue shut.
Where Surgical Clips Are Used
The most common setting is laparoscopic cholecystectomy, the minimally invasive surgery to remove the gallbladder. During this procedure, the surgeon must securely close the cystic duct (the tube connecting the gallbladder to the bile duct) and the cystic artery before detaching the gallbladder. Clips are the standard method for this. If the cystic duct isn’t sealed properly, bile can leak into the abdomen, causing infection and potentially serious complications.
Beyond gallbladder surgery, clips are used in vascular procedures to seal off blood vessels, in neurosurgery to close aneurysms (weak, ballooning spots in blood vessel walls), and in tumor removal to control bleeding from small vessels. They’re also placed during some biopsies as tiny markers so the surgical site can be located later on imaging.
What Clips Look Like on Imaging
If you’ve had surgery involving clips and later get a CT scan or X-ray, those clips will likely show up. Metal clips appear as small, bright white objects on imaging. Polymer locking clips (like the Hem-o-lok brand) are also visible on CT, appearing as small radiopaque objects with a density around 222 Hounsfield Units, a measurement radiologists use to characterize what they’re seeing.
This visibility matters for a practical reason: if you develop pain months or years after surgery and get a CT scan, those clips can be mistaken for foreign bodies, kidney stones, or even signs of disease recurrence. Knowing you have surgical clips, and telling your radiologist about them, helps avoid unnecessary worry or follow-up procedures. The clips will generally appear near the site where the original surgery took place, such as near the bile duct area after gallbladder removal or near the renal hilum after kidney surgery.
MRI Safety With Clips in Place
One of the most common concerns people have after learning they have permanent clips is whether they can safely get an MRI. The answer depends on the clip material. When clips made from ferromagnetic metals (metals attracted to magnets) are exposed to the strong magnetic field inside an MRI machine, they can shift position or heat up, potentially damaging nearby tissue.
Most modern surgical clips are made from titanium or specific stainless steel alloys that are classified as MRI-safe or MRI-conditional. “Conditional” means they’re safe under specific conditions, such as a certain magnetic field strength. Your surgical records should note the brand and type of clip used. The website mrisafety.com maintains a searchable database where specific clip models are listed with their safety classifications. If you’re unsure what clips you have, let the MRI team know before the scan so they can verify safety.
Possible Complications
Surgical clips are generally very safe, but complications can occur. The most relevant risks include:
- Clip slippage: If a clip loosens or comes off the structure it was clamping, the vessel or duct can reopen. In gallbladder surgery, this can lead to bile leakage, which may require additional intervention.
- Migration: In rare cases, clips can slowly shift from their original position. After cholecystectomy, migrated clips can end up inside the bile duct and act as a seed for stone formation. This is uncommon, with only about 100 cases reported in the medical literature despite millions of cholecystectomies performed worldwide each year.
- Thermal injury: During laparoscopic surgery, energy-based instruments used near the clip site can transfer heat to the clip, potentially causing tissue damage at the clamp point.
- Imaging interference: Metal clips can create artifacts on CT scans, appearing as bright streaks or distortions that obscure surrounding anatomy and make it harder for radiologists to read the images clearly.
For most people, surgical clips cause no symptoms or problems whatsoever. Titanium clips stay in place for life, surrounded by a thin capsule of scar tissue, and are essentially inert. Absorbable clips eliminate long-term concerns entirely by dissolving within six to eight months. If your surgeon used clips during a procedure, they’ll typically note the type and number in your operative report, which becomes part of your medical record.