A stitch left in your body after surgery or wound repair is not automatically an emergency, but it does need attention from a healthcare provider. Whether it is a surface skin suture that was missed at a follow-up visit or an internal stitch discovered months later, the right first step is always the same: contact the surgeon or doctor who placed it. Most retained stitches can be removed in a brief office procedure, and the sooner they come out, the lower the chance of complications like infection, scarring, or a chronic inflammatory reaction called a suture granuloma. What happens next depends on the type of stitch, where it is in your body, and how long it has been there.
How Stitches End Up Getting Left In
Not every retained stitch is a medical mistake. There are a few common scenarios. The most frequent is a surface suture that a patient was supposed to return to have removed but never did, either because the appointment was missed or the wound looked healed and the stitches seemed unnecessary. Another possibility is a deep internal suture placed during surgery. These are usually absorbable, meaning the body is supposed to break them down over weeks or months, but sometimes the material does not dissolve completely or takes far longer than expected. A third scenario involves a genuinely forgotten stitch, where one suture was missed during a removal appointment because it was hidden by swelling, a scab, or scar tissue.
In larger surgical procedures, retained suture material can also be an oversight during closure. Legal analysis of malpractice cases involving hernia repair, for instance, found that retained foreign bodies appeared in roughly one in six lawsuits reviewed.1PubMed. Medical malpractice and hernia repair: an analysis of case law That does not mean one in six surgeries has this problem; it means that when something does go wrong after hernia repair and ends up in court, a forgotten item is a recurring theme.
Absorbable Versus Non-Absorbable Stitches
The type of suture material matters a great deal in determining how urgent the situation is. Absorbable stitches are designed to lose their strength and eventually dissolve inside the body. Some fast-absorbing types weaken within about nine to twelve days and lose around 30% of their strength by three weeks.2MDPI. Short-Term Hydrolytic Degradation of Mechanical Properties of Absorbable Surgical Sutures: A Comparative Study – Section: 3. Results Others maintain their strength for well over 40 days. In theory, your body handles the cleanup. In practice, absorption timelines are not perfectly standardized and can vary from person to person. A case report involving silk sutures left after a tooth extraction found that even material considered partially resorbable was only partially broken down, with the remaining portion becoming embedded in the healing bone.3PubMed Central. Partially resorbed unremoved silk sutures after tooth extraction: A unique Case report
Non-absorbable stitches, such as nylon or polypropylene, are designed to stay intact permanently. These are the ones that absolutely need to come out if they are in the skin, because the body will never dissolve them on its own. When non-absorbable stitches are used internally, such as in tendon repairs or hernia meshes, the surgeon expects them to remain. But if one migrates, works its way to the surface, or starts causing pain, it becomes a problem that requires intervention.
Signs a Retained Stitch Is Causing Trouble
Many retained stitches sit quietly for a while before causing symptoms. The warning signs to watch for include:
- Redness and swelling: persistent or worsening inflammation around the wound or scar, especially if it develops weeks or months after the initial healing.
- A lump or nodule: a firm bump forming under or near the scar line, which may be tender to the touch.
- Drainage: any fluid, pus, or cloudy discharge coming from the wound area, especially if the wound had appeared fully closed.
- A thread poking through: sometimes a suture end will literally emerge from the skin. This is called suture extrusion, and it is your body pushing out a foreign object.
- Recurring pain: discomfort at the surgical site that does not improve or that returns after an initial pain-free period.
If you notice any of these, call the office of the doctor who performed your procedure. You do not need to go to the emergency room unless you have a high fever, rapidly spreading redness, or signs of a serious infection.
The Infection Risk
One of the bigger concerns with a retained stitch is its potential to become a home for bacteria. Suture material sitting in tissue provides a surface where bacteria can attach and form a biofilm, which is essentially a thin, slimy colony that shields the organisms from your immune system and from antibiotics. Research examining chronic surgical-site infections found bacteria including staphylococci living in biofilms on retained suture material, and in those cases, antibiotics alone could not clear the infection.4PubMed Central. Chronic Surgical Site Infection Due to Suture-Associated Polymicrobial Biofilm – Section: Results The infections only resolved after the stitches themselves were physically removed.
A separate study examining persistent surgical-site infections confirmed the same pattern across 15 patients. Every one of them had visible biofilm on their retained sutures, and every one was cured only once all the suture material was taken out.5PubMed Central. Bacterial Biofilms on Implanted Suture Material Are a Cause of Surgical Site Infection This is why a wound that keeps getting infected despite antibiotic treatment should prompt your doctor to consider whether foreign material is still present underneath.
The type of suture material also influences how aggressively bacteria colonize it. Silk sutures, an older material still sometimes used, tend to provoke a stronger inflammatory response and attract more bacterial adherence than synthetic alternatives like nylon or polyglecaprone.6PubMed Central. Tissue Reactions to Various Suture Materials Used in Oral Surgical Interventions – Section: Results If you know silk sutures were used and one was left behind, there is a slightly stronger reason to have it addressed promptly.
Suture Granulomas
When a retained stitch does not get infected, the body sometimes walls it off in a different way by forming a granuloma. This is a small nodule of immune cells that surrounds the foreign material, trying to contain something it cannot break down. A granuloma can form around both absorbable and non-absorbable stitches.7PubMed Central. An Exceptional Case of Suture Granuloma 30 Years Following an Open Repair of Achilles Tendon Rupture: A Case Report – Section: Introduction They often show up as a painless lump near a surgical scar, sometimes appearing years or even decades after the original operation.
A suture granuloma is not dangerous in itself, but it can cause real problems in two ways. First, it can be uncomfortable, growing large enough to press on surrounding tissue or to be cosmetically noticeable. Second, and more unsettling for patients, it can look like something much more serious on imaging. One reported case involved a granuloma detected on a PET scan 56 years after an appendectomy. Because the patient had a history of lymphoma, the lump lit up on imaging in a way that looked like cancer recurrence, and even a biopsy could not immediately rule out lymphoma. The patient ultimately had the mass surgically removed, and it turned out to be nothing more than granulomatous inflammation wrapped around old suture material.8PubMed Central. PET-positive suture granuloma of abdominal wall 56 years post-appendicectomy mimicking recurrence of lymphoma
Another case report documented a granuloma extending into the abdominal cavity five months after an appendectomy. Pathology confirmed it was an inflammatory reaction to retained suture material, not a tumor.9PubMed Central. Suture granuloma extending intra-abdominally, detected five months postappendectomy – Section: Outcome and follow-up The practical takeaway is that if you develop a lump near an old surgical scar, mention your surgical history to whatever doctor is evaluating it. Knowing that suture material could be present narrows down the possibilities quickly.
How Retained Stitches Are Found
Surface stitches are usually visible or palpable during a physical exam. The trickier cases involve deeper retained sutures, where imaging is needed. Ultrasound is the go-to first step. On an ultrasound screen, a retained suture shows up as a bright, echogenic line in the tissue, and if there is a reaction around it, you may see a darker fluid-filled area surrounding it.10Journal of Orthopedic Research and Therapy. Magnetic Resonance and Ultrasound Imaging of Intra-Tendinous Suture Reaction: A Case Series – Section: Discussion
Color Doppler ultrasound, which visualizes blood flow in real time, can be especially useful. In one reported case, color Doppler was used not only to identify a retained anchoring suture but also to trace its exact path through the tissue, allowing the doctor to remove it with a minimally invasive “retract-and-cut” technique rather than performing a full surgical exploration.11PubMed Central. A Diagnostic and Therapeutic Approach to Retained Anchoring Sutures: Color Doppler Ultrasound for Diagnosing and the Retract-and-Cut Technique for Minimizing Invasive Interventions MRI can also pick up suture reactions, though ultrasound tends to be the faster and cheaper option and in some cases catches material that MRI misses.
How Removal Works
For surface stitches, removal is quick and straightforward. The doctor lifts the suture with forceps, snips it, and pulls it out. If the stitch has been there long enough for tissue to grow over it, a small amount of local anesthetic may be used and the doctor may need to make a tiny nick to access the buried end. The whole process usually takes minutes.
Deeper retained sutures require more planning. If the stitch is near the surface and its path can be traced on ultrasound, a minimally invasive extraction is often possible, as described with the retract-and-cut approach. When the suture is embedded in deeper tissue, or when a granuloma has formed that needs to come out along with it, minor surgery under local or general anesthesia may be necessary. In biofilm-related infections, complete removal of every fragment of suture material is the goal. Leaving even a small piece behind can allow the infection to recur.
Timing matters. Animal studies on nylon skin sutures have shown that local tissue reactions escalate the longer stitches remain. By about three weeks, granulation tissue and inflammatory cell buildup are noticeable, and by five weeks, researchers observed loss of the outer skin layer, destruction of hair follicles and sweat glands, fibrosis, and dense immune-cell infiltration at the suture site.12Nigerian Veterinary Journal. Duration-dependent effects of nylon skin sutures on some systemic inflammatory markers and local tissue reaction That research recommended removing nylon skin sutures no later than 21 days after placement to avoid these progressive changes. In humans, the standard is even faster: most skin sutures are removed between 5 and 14 days depending on body location.
Retained Stitches Near the Eyes
One of the more alarming scenarios involves sutures left behind after eyelid surgery, particularly the “buried suture” technique used in double-eyelid blepharoplasty. Because the inner surface of the eyelid sits directly against the cornea, even a small thread end poking through can cause serious eye problems. A case series of patients who developed recurrent corneal erosion after blepharoplasty found that retained nylon sutures had been left for anywhere from one to ten years before symptoms appeared. The patients experienced pain, tearing, and corneal damage that did not respond to artificial tears or contact lens treatment. Their symptoms resolved within a week once the offending stitches were removed.13PubMed. Recurrent corneal erosion caused by retained sutures in blepharoplasty
The consequences can be far worse than irritation. A review of suture-related complications after buried-suture blepharoplasty documented cases of corneal ulcers and even one patient who developed a perforating eye injury when a suture penetrated through the sclera, ultimately requiring a major surgery called a vitrectomy to address an infection inside the eye.14PubMed. Cause and Management of Suture-related Ocular Complications after Buried-suture Double-eyelid Blepharoplasty A separate study of 14 patients with corneal complications after the same procedure found that every patient had symptoms of light sensitivity, tearing, pain, and a foreign-body sensation, with six developing corneal ulcers.15PubMed Central. Misdiagnosis and Treatment of Corneal Complications Caused by Suture Exposure After Buried-Suture Double-Eyelid Blepharoplasty If you have had any kind of eyelid surgery and develop new eye irritation, redness, or a scratchy feeling that will not go away, a retained stitch is worth considering and mentioning to your eye doctor.
When a Retained Stitch Mimics Cancer
The case of the PET-positive granuloma mimicking lymphoma is not a one-off oddity. A review of retained surgical items found that chronic cases involving the extremities often present as a mass that looks suspicious for a sarcoma or other type of malignancy.16International Journal of Academic Medicine. Retained surgical items: Building on cumulative experience – Section: Skin and soft tissues The lump is firm, it grows slowly, and on imaging it can have features that overlap with soft-tissue tumors. This means biopsies, anxiety, and sometimes unnecessary surgery before the true cause is identified.
If you know you have an old surgical scar anywhere on your body and a lump develops near it, always volunteer that history to your doctor, even if the surgery was decades ago. Suture granulomas are capable of sitting dormant for years and then becoming symptomatic or suddenly visible on a scan done for an unrelated reason. Knowing about the prior surgery lets the radiologist or pathologist consider a benign foreign-body reaction as a leading explanation rather than jumping straight to a cancer workup.
The Human Cost and Patient Experience
Beyond the physical complications, living with a retained surgical item takes a psychological toll that often gets overlooked. An analysis of Australian case law involving retained surgical items found that ongoing pain was the most frequently reported physical complaint, appearing in nearly every civil case reviewed. In a third of those cases, patients also suffered psychosocial symptoms severe enough to need treatment.17PubMed Central. Exploring Risk, Antecedents and Human Costs of Living with a Retained Surgical Item: A Narrative Synthesis of Australian Case Law 1981-2018 The anxiety of knowing something foreign is in your body, combined with frustration at a preventable error, can be significant. If you are dealing with this, it is reasonable to ask your surgeon not only about physical management but also to be forthcoming about what went wrong and what comes next. You are also within your rights to seek a second opinion if you feel your concerns are being dismissed.
Who Bears Responsibility
From a legal perspective, the surgeon bears primary responsibility for ensuring nothing is left behind. An analysis of the legal framework around retained foreign bodies emphasized that both the lead surgeon and any assistant are liable for not thoroughly checking the surgical site before closing it. While nurses perform instrument and material counts, the count is considered an additional safety measure and does not substitute for the surgeon’s own inspection.18PubMed. Penal liability from retained foreign body inside the surgical site In practical terms, this means that if a retained stitch causes you harm, the responsibility falls squarely on the surgical team, not on you for failing to notice it.
This does not mean every retained stitch warrants a lawsuit. Many cases involve skin stitches that were supposed to be removed at a follow-up but were not, sometimes because the patient did not return. In those situations, the picture is murkier. The best thing you can do is attend every scheduled follow-up, ask at each visit whether all stitches have been removed, and keep records of your post-surgical care. If you notice something that feels like a stitch months or years later, documenting when symptoms started gives you a clearer path whether the next step is a simple removal or a more involved conversation about what happened.
What Suture Material Means for Your Risk
Not all stitches provoke the same reaction if left behind. Research comparing tissue responses to different suture materials consistently finds that silk causes the most intense inflammatory reaction and the slowest healing, while synthetic monofilament sutures like nylon tend to cause the mildest tissue response.6PubMed Central. Tissue Reactions to Various Suture Materials Used in Oral Surgical Interventions – Section: Results Absorbable synthetics like polyglecaprone and polyglactin (brand names Monocryl and Vicryl) fall somewhere in between, with one comparative study finding that Vicryl produced the mildest tissue reaction among several absorbable options.19PubMed. Comparison of four different suture materials in soft tissues of rats – Section: RESULTS
An animal study comparing silk, nylon, polypropylene, and polyglactin found that while silk showed the highest rates of moderate inflammatory infiltration, the overall differences among materials were not statistically significant for inflammation, fibrosis, or new blood vessel formation.20Journal of Experimental and Molecular Pathology. A comparative study of biological reactions to different suture materials in animal model The takeaway is that no suture material is truly inert. Even the best-tolerated synthetic will eventually provoke a local reaction if it stays where it is not supposed to be. The differences in severity exist, but the message is the same regardless of material: get it out.
Practical Steps If You Suspect a Retained Stitch
If you think a stitch has been left in, here is a sensible course of action:
- Do not pull it yourself: tugging on what looks like a thread can break it off below the skin, push bacteria deeper into the wound, or damage healing tissue. Even if you can see the end, let a professional handle it.
- Call the surgeon’s office: describe what you are seeing or feeling. They will usually bring you in within a few days. If you notice signs of infection like spreading redness, warmth, pus, or fever, request a same-day or next-day appointment.
- Bring your surgical records: knowing what type of suture was used, when the surgery was, and what follow-up was planned helps the doctor decide how urgent the situation is.
- Ask about imaging: if the stitch is not visible on the surface and you have a lump or recurring pain near a scar, ask whether an ultrasound would help locate the material before any procedure is attempted.
- Follow through on removal: once a retained stitch is identified, do not put off having it removed. The tissue reaction only escalates with time, and what could be a five-minute office procedure now may require minor surgery later.
A retained stitch is among the most fixable complications in all of surgery. The earlier you act, the simpler the fix tends to be.