Suturing a central venous catheter (CVC) to the skin is the most common method of securing the line after insertion. The goal is straightforward: keep the catheter from migrating or pulling out while avoiding excessive tension that damages the surrounding skin. Most central lines are secured using a combination of a clamp stitch, a compression suture at the insertion site, and a finger-trap technique along the catheter body, typically with 2-0 or 3-0 braided silk or polyester suture on a curved needle.
Suture Material and Setup
The standard choice for central line securement is 2-0 or 3-0 braided, non-absorbable suture. Silk is the most traditional option because it handles well and ties securely, though braided polyester is also widely used. The suture comes on a small curved cutting needle, which makes it easier to pass through skin near the catheter. You want a non-absorbable material because the suture needs to hold for the life of the line, which can range from days to several weeks.
Before placing any sutures, the insertion site should be prepped and draped with full sterile technique. The catheter position should already be confirmed, and the operator should have a clear view of the skin anchor points and the catheter’s built-in clamp or wing.
The Three Components of Securement
A fully secured central line typically uses three suture elements working together. Each one addresses a different failure point.
Clamp Stitch
Most central line kits include a plastic clamp or wing that sits against the skin near the insertion site. The first suture secures this clamp to the skin. Pass the needle through the skin on one side of the clamp, loop the suture through or over the clamp’s eyelets, then pass back through the skin on the other side. Tie down with a square knot. This anchors the rigid part of the catheter assembly and prevents gross movement.
Compression Suture at the Insertion Site
A simple interrupted suture is placed at the skin puncture site itself, snugging the skin around the catheter where it enters. This serves two purposes: it reduces the gap between the catheter and the wound edge (which helps limit bacterial entry) and adds a second fixation point independent of the clamp. The stitch should approximate the skin around the catheter without cinching so tightly that it blanches or strangles the tissue. Excessive tension at this point causes ischemic necrosis of the skin edges, which paradoxically increases infection risk and can cause the suture to pull through.
Finger-Trap Technique
The finger trap is what prevents the catheter from sliding in or out even if the clamp loosens. Place a single stitch through the skin near the insertion site, then wrap the two free ends of the suture around the catheter body in alternating spirals, similar to a Chinese finger trap. Carry the wraps distally along the catheter to the point where the lumens branch apart, then tie the ends together. This distributes the holding force along the length of the catheter rather than concentrating it at one point. In laboratory testing, the combination of all three techniques (clamp, compression, and finger trap) produced the highest resistance to dislodgement across catheters from multiple manufacturers.
Getting the Tension Right
The most common technical error is tying sutures too tightly against the skin. When a suture compresses the skin beyond its perfusion threshold, the tissue underneath loses blood supply. Over hours to days, this leads to localized skin death, breakdown of the wound edges, and a higher chance of both infection and suture failure. The tissue turns white or dusky, then eventually sloughs, leaving the catheter less secure than it would have been with a properly tensioned stitch.
The practical rule is to tie your knots so the suture sits firmly against the skin without indenting it. You should be able to slide the tip of a fine instrument under the knot. If you see skin blanching immediately after tying, the suture is too tight and should be replaced.
Differences by Insertion Site
The internal jugular, subclavian, and femoral veins each present different challenges for suture securement. The internal jugular site sits in the neck where head movement constantly tugs on the catheter, so secure fixation is especially important. This site also carries a higher rate of infectious complications compared to the subclavian approach. In one controlled comparison, central line bloodstream infections occurred at a rate of 6.9 per 1,000 catheter-days with internal jugular lines versus zero with subclavian lines.
The subclavian site offers a more stable skin surface with less movement, which makes sutures less prone to loosening. However, the skin over the clavicle can be thin in some patients, so there is less tissue to anchor into. Femoral lines sit in the groin crease where moisture and movement are constant concerns, and sutures here tend to loosen faster.
Regardless of site, the suturing principles are the same. What changes is how vigilant you need to be about checking the sutures in the days after placement. Even with proper technique, about 42% of sutured central lines show at least 2 millimeters of migration over time, and roughly 2% experience unplanned removal.
Sutureless Alternatives
CDC guidelines include a recommendation to consider sutureless securement devices to reduce infection risk. These adhesive-based devices grip the catheter hub and stick to the surrounding skin, eliminating needle punctures that can serve as entry points for bacteria. They work well with PICCs and certain types of tunneled catheters that have a compatible adapter molded into the line.
That said, sutureless devices cannot be used with all catheter types. Standard silicone tunneled catheters, for example, lack the built-in adapter needed for these devices. For tunneled cuffed lines, the initial suture is typically removed at around four weeks, once the catheter’s subcutaneous cuff has had time to become anchored by tissue ingrowth. Leaving the suture in longer than necessary increases the risk of local infection at the stitch site.
In head-to-head comparisons, neither sutures nor integrated securement devices have shown a clear advantage in preventing catheter-related bloodstream infections. Both methods effectively keep the line in place when used correctly. The choice often comes down to the catheter type, institutional protocol, and the clinical scenario.
Suture Removal During Line Discontinuation
When it is time to remove the central line, the sutures come out first. Start by removing the dressing and carefully inspecting the insertion site. Identify every anchoring suture, including any finger-trap wraps along the catheter body. Cut each suture close to the skin on one side of the knot and pull it free. Leaving a suture fragment behind can cause a foreign-body reaction or serve as a nidus for infection.
Once all sutures are removed and the site has been inspected for signs of infection (redness, purulence, tenderness), the catheter can be withdrawn. The key detail during this step is making sure no suture is still tethering the catheter to the skin before you pull. Attempting to remove a line with a suture still in place can tear the skin or, in rare cases, damage the catheter itself.